Derang Jitpl-o&m Manual_xrp1103-1 Mill

M/s JINDAL INDIA THERMAL POWER LTD

C

The copyright on all documents, drawings and other instruments are the property of Bharat heavy Electricals Limited. These shall not be used without their express written permission in any form or part thereof for any other purposes than for which it is sent to receiver.

C

The copyright on all documents, drawings and other instruments are the property of Bharat heavy Electricals Limited. These shall not be used without their express written permission in any form or part thereof for any other purposes than for which it is sent to receiver.

Bowl Mill

1.0.

INTRODUCTION

XRP1103

1.0

INTRODUCTION ................................................................................................................................... 1

2.0

TECHNICAL DESCRIPTION ........................................................................................................................ 2

2.1 MILL TECHNICAL TECHNICAL DATA:............................................................. .............................................................................................................................. ................................................................... 2 2.2 3.0

MAJOR ASSEMBLIES: ..................................................... ...................................................................................................................... ............................................................................. ............ 3

OPERATION: ............................................................................................................................................ 5 CHECKLIST OF “DO’S” -

BOWL MILL........................................................................................................... 5

3.2 CHECK LIST OF “DON’TS”

- BOWL MILL ............................................................ ......................................................................................................... ............................................. 8

3.1

3.3

PRINCIPLES OF OPERATION: ................................................................ ....................................................................................................................... ....................................................... 9

3.4

OPERATING PARAMETERS: .............................................................................................. ..................... 12

3.5 START - UP: ................................................................................................................................................. 13 3.6

NORMAL SHUT DOWN: ......................................................... ....................................................................................................................... ................................................................ .. 14

3.7

EMERGENCY SHUT DOWN: ................................................................ ..................................................................................................................... ..................................................... 14

3.8

START UP AFTER EMERGENCY SHUT DOWN: ............ .............................................................. ........................................................................... ............. 15

3.9

MILL FIRES: ...................................................... ....................................................................................................................... ...................................................................................... ..................... 16

3.10

FIRE EXTINGUISHING PROCEDURES: ........................................................... ...................................................................................................... ........................................... 17

3.11

MILL REJECTS: ....................................................................................................................................... 19

Bowl Mill

1.0.

5.8

INTRODUCTION

XRP1103

LIST OF EQUIPMENT ................................................................................................................................. 31

TABLE - 6 ........................................................................................................................................................ 32 5.9

LOCKING GUIDELINES .............................................................................................................................. 32

5.10 SPARE PARTS STOCK................................................................................................................................ 33 6.0

MILL OPTIMIZATION .............................................................................................................................. 36

7.0 TROUBLESHOOTING ............................................................................................................................... 38 TABLE- 8 ......................................................................................................................................................... 39 8.0 8.1

PULVERISED COAL SAMPLING: ........................................................................................................... 43 NON-ISOKINETIC SAMPLING METHOD: (For ISO KENITIC SAMPLING refer ............................................ 43

to O& M manual of Vendor, if applicable) ........................................................................................................ 43 8.2

ADJUSTMENT OF FINENESS: ............................................................................................ ..................... 45

8.3 MILL WEAR LIFE ASSESSEMENT ................................................................................................................ 49 9.0. MAINTENANCE ........................................................................................................................................ 50 10.0 GENERAL MAINTENANCE: ...................................................................................................................... 51 10.1 INSTRUCTIONS FOR INTERFERENCE FIT: .........................................................................................

53

Bowl Mill

1.0.

INTRODUCTION

XRP1103

12.4 JOURNAL HEAD TO JOURNAL SHAFT ASSEMBLY ................................................................................... 108 12.5 Adjustment of the Seal Air Gap ............................................................................................................... 109 13.0 STORAGE AND PRESERVATION OF MILL COMPONENTS ..................................................................... 111 13.1 PRESERVATION WITH PRESERVATIVE ................................................................................................... 111 TABLE-13 Recommended preservatives for PGB ........................................................................................ 111 13.2

SPARE ROLLER JOURNAL ASSEMBLIES PRESERVATION:...................................................................... 112

13.3

PRESERVATION OF JOURNAL ASSEMBLIES IN THE MILL: ..................................................................... 112

13.4

DRIVE COUPLINGS: .............................................................................................................................. 112

13.5

MILL DISCHARGE VALVES ASSEMBLY: ................................................................................................. 112

13.6

INTERIOR AREAS: ................................................................................................................................. 113

13.7

MILL MOTOR: ...................................................................................................................................... 113

13.8

GENERAL: ............................................................................................................................................ 113

13.9 LONG TERM PRESERVATION OF THE PLANETARY GEAR BOX: ................................................................ 113 14.0 SPARES ............................................................................................................................................... 118 14.1

RECOMMENDED SPARES LIST .............................................................................................................. 120

Bowl M ill

CONTENTS

XRP1103

LIST OF DRAWINGS

Fig

Description

No.

A B C D E F G H. I J K L M

Bowl Mill cross-section Bowl Mill General Arrangement Drawing Planetary gear box assembly Mill foundation drawing Deflector Control Assembly Removal and Weight of Mill Parts Gear box withdrawal procedure Bull ring segment assy. Tightening Torque for Fasteners Roll Removing Fixture Special Tools Journal opening frame liner assembly Protective Seal Application (17 deg tilt) venturi

Bowl Mill

1.0.

1.0

INTRODUCTION

XRP1103

INTRODUCTION

Bowl mills are employed to pulverize the pre-crushed raw coal to the required fineness before it is admitted into the boiler furnace for combustion. The operating characteristics of bowl mills make it the best mill available for the direct firing system of the coal. The best features of all the pulverisers have been incorporated in the design of the bowl mill. The mill output can be easily varied, as per the turndown ratio from its minimum to maximum load and it will operate for long periods without mechanical problems or stoppages for cleaning, oiling or adjusting.

Crushed raw coal at a controlled rate is fed into the revolving bowl of the Bowl Mill. Centrifugal force feeds the coal uniformly over the replaceable grinding ring where independently spun rolls exert the required grinding pressure. The rolls do not touch the grinding ring even when the mill is empty. Therefore the Bowl Mill operates silently without the rumble that is characteristic of the mills in which there is metallic contact between the grinding elements. This mill is designated as XRP 1103 Bowl Mill where

Bowl Mill

2.0.

2.0

TECHNICAL DATA

XRP1103

TECHNICAL DESCRIPTION

2.1 MILL TECHNICAL DATA:

TYPE OF MILL

XRP 1103

MILL BASE CAPACITY(T/Hr)*

78.5 (Design Coal)

MOTOR SPEED(RPM)

990

TOTAL WEIGHT OF MILL(T)

170

(including motor) TYPE OF LOAD

Moderate Shock Load

ROTATING WEIGHT OF MILL(T)

22.88

SPRING RATE(Kg/cm)

5359

SPRING PRE LOAD(Kg)

9500

MILL OUTLET TEMPERATURE RANGE

65ºC -90ºC

AIR FLOW (T/Hr)

136

FINENESS *

70% Through 200 Mesh 98% Through 50 Mesh

Bowl Mill

2.0.

2.2

TECHNICAL DATA

MAJOR ASSEMBLIES:

a)

PLANETARY GEAR BOX AND BOWL HUB ASSEMBLY:

Planetary gear box is used to give required torque to the bowl & bowl hub Assembly which is directly mounted and bolted to the gear box top table. The direction of torque transmission in planetary gear box changed from horizontal

to

vertical.

The

bowl

assembly consists of Bull ring assembly (mounted

on

the

bowl),

Skirt

&

Scrapper Assembly and vane wheel assembly (attached to the bowl).

XRP1103

Bowl Mill

2.0.

TECHNICAL DATA

XRP1103

c) SEPARATOR BODY ASSEMBLY:

The

separator

body

holds

the

components that give necessary grinding

pressure

(journal

spring

assembly), journal assembly and also the components that direct the coarse sized coal particles back to the bowl for re grinding.

d) ROLLER JOURNAL ASSEMBLY:

The roller assembly consists of journal shaft,

Bowl Mill

2.0.

TECHNICAL DATA

e) MILL DISCHARGE VALVE ASSEMBLY: The mill discharge valve assembly consists of four multiport outlet and mill discharge valves mounted on the multiport outlet plate. Air cylinders operate the flaps in the mill discharge valves.

Solenoid

valves

and

limit

switches are provided to effect and indicate the open or close position of the flap. This assembly does the distribution of pulverised fuel into four pipes and also it isolates the mill from boiler when required

XRP1103

Bowl Mill

3.0.

3.0

OPERATION

XRP1103

OPERATION: Pulverization is the method of preparing raw coal for complete burning. Mechanically pulverizing coal into fine powder enables the pulverized fuel to burn like an oil or gas in a steam generator, thus allowing more efficient combustion. The Pulverised coal Transported by hot air and introduced directly into th e boiler furnace zone for combustion.

3.1

A.

CHECKLIST OF “DO’S” - BOWL MILL

Before start up : 1.

Check lubrication with reference to proper level and cleanliness of lubricants.

2.

Check sufficient raw coal in the raw coal bunker.

3.

Check for proper operation of mill discharge valves, hot air shut off gate, hot air damper and cold air damper and seal air system.

4.

Check that all three roller journal pressure springs are compressed to the same

Bowl Mill

3.0.

OPERATION

XRP1103

15.

Check that cold air gate is open.

16.

Check that adequate primary air pressure is available in the hot air header.

17.

After the mill lube system has been started at least 15 minutes before, checkup the oil flow, temperature and pressure to the planetary gear box.

18.

Feeder must be started only after the mill has been started and warmed up.

19.

Check that there is proper coal flow into the mill (an annunciation for the no coal flow from raw coal feeder will come when there is no coal flow to the mill)

20.

During the initial period and load picking up of the mill check that sufficient ignition energy is available in the furnace till Pulverised fuel from each mill attains selfsustained combustion.

21.

During a relight-up of the unit, after a unit trip out, ensure that the discharge valves of all non-operating coal laden pulverisers are closed whenever a fresh fuel (oil/coal) elevation is cut in until the furnace draft has stabilized, to avoid any Surging back of furnace gases into the coal laden pulverisers in case of furnace

Bowl Mill

3.0.

OPERATION

XRP1103

9.

Check level and quality of lube oil in lube oil tank and journal assemblies regularly.

10.

Check for any abnormal sound.

11.

Check for any air or pulverized coal leakage and attend to them promptly.

12.

Check for hot air leakage through the Gland packing seal. This indicates trouble with the Labyrinth Seal and or Gland packing seal or inadequate seal air supply, pressure and flow.

C.

SHUT-DOWN :

i)

During Normal Shut-Down : 1.

Cool the mill during and after shut-down.

2.

Run the mill for at least 5 minutes until coal is completely emptied before shut down.

3.

Keep cold air regulating damper slightly throttled to approximately 5° after the mill has stopped.

Bowl Mill

3.0.

2.

OPERATION

XRP1103

If a fire exists completely through the mill and fuel piping, clear all personnel from the area surrounding the mill, its associated feeder and fuel piping. Shut off the feeder and allow the mill to clear itself all the fuel. Maintain a flow of cold air through the mill until all evidence of fire has disappeared and the mill is cold, then shut- down and isolate the mill. Spray emergency firefighting water into the mill to quench the fire.

3.

When a fire has been extinguished and the mill has cooled, stop the mill, open inspection doors carefully and thoroughly clean the interior of the mill of any accumulation including coal water slurry. Check lubricants for evidence of carbonizing. Check all parts where the fire has occurred for any damage, especially the O Rings & Oil seals.

3.2 CHECK LIST OF “DON’TS” - BOWL MILL

BEFORE START-UP

OPERATION

Bowl Mill

3.0.

OPERATION

XRP1103

1.

Do not Open any of the Manhole Doors to get into the mill for maintenance without ensuring that driving motor has been isolated, mill discharge valve is closed (if the boiler is in operation), and the mill is isolated from the air side as well as raw coal side.

2.

Do not use steel hammers directly on grinding rolls and bull ring segments.

3.

Do not use direct flame torch for heating bearing assemblies.

4.

Do not leave tools, work pieces, electrodes etc., inside the mill after maintenance work has been carried out.

5.

Do not carry out maintenance work inside the mill without proper personnel safety equipment.

6.

Do not weld on the bowl or any part attached to it unless the welding machine is grounded to the bowl to prevent arching across bearing assemblies.

7.

Do not use 230 volts supply lights, and electrical grinders inside the mill (Use 24 volts supply for hand lamps as a safety measure).

Bowl Mill

3.0.

OPERATION

XRP1103

grinding. The partially ground coal moves outward and over the edge of the bowl. Heated air enters the mill side housing below the bowl and is directed upward around the bowl outside diameter and separator body annulus, by the rotating vanes. It continues upward and into the deflector openings in the classifier at the top of the inner cone, then out through the venturi and multiple port outlet assembly. As the air passes upward around the bowl, it picks up the partially pulverized coal; particles are carried up through the deflect or openings of the classifier. The deflector blades in the openings cause the coal - air mixture to spin within the inner cone. The angle of the blades determines the velocity of the spin and the resulting fineness of the finished product. Coarser Pulverised coal particles are returned through the inside of the inner cone to the bowl for further grinding. Coal that is Pulverised t o the desired fineness leaves the pulveriser and enters the fuel piping system. Any tramp iron or dense and difficult to grind foreign material in the coal feed is carried over the top of the bowl, where it drops through the air stream and rotating vanes to the mill bottom. Pivoted scrapers attached, to the lower skirt, sweep the tramp iron or other material to the tramp iron discharge opening. The tramp iron spout is fitted with a valve. Under normal operation this valve remains

Bowl Mill

3.0.

OPERATION

XRP1103

For good pulveriser performance, the temperature of the coal-air mixture leaving the classifier should be maintained as high as possible within the safe temperature limit for that particular coal. Too high an outlet temperature may lead to a pulveriser fire. The safe temperature limit for a given coal depends on the percentage of volatile matter, moisture and pyrites either individually or a combination of them in the coal. BHEL pulveriser systems are designed to perform effectively with coals with a wide range of moisture content and grindability. In order to obtain rated capacity from the pulveriser, it is necessary to have sufficient hot air entering the pulveriser to dry the coal, sufficient pressure on the rolls to pulverise it and proper setting of the classifier deflector vanes to obtain fineness reasonably close to that for which the pulveriser is designed. Operating experience will help determine the pulveriser’s optimum conditions for a given coal.

CAUTION PULVERISER OUTLET TEMPERATURE IN EXCESS OF 95° C COULD RESULT IN PULVERISER FIRES.

Bowl Mill

3.0.

3.4

OPERATION

XRP1103

OPERATING PARAMETERS: To meet the safe and optimized mill operating criteria, the following operating parameters must be established for the given coal i). MILL AIR FLOW:

Mill should be operated at the design air flow at all loads. Operating at higher air flow will cause excess wear and upset the performance of classifier etc. If mill is operated at lower air flow it may result in coal rejects, low bowl differential pressure, excess fineness, coal settlement etc. The air flow is controlled by the simultaneous operations of hot and cold air dampers. ii). MILL OUTLET TEMPERATURE: For good pulverizer performance, the temperature of coal air mixture leaving the classifier should be maintained as high hi gh as possible within the safe temperature limit of the coal coal being ground. ground. Too high a outlet outlet temperature may lead to a pulverizer fire. When grinding coal with a volatile content below 25% on an “as received” basis, the mill outlet temperature outlet temperature of 75°C to 80°C is recommended. If a high volatile coal is also a high sulphur coal, the maximum safe operating

Bowl Mill

3.0.

OPERATION

XRP1103

TECHNICAL POINT IF LOW CALORIFIC VALUE OF COAL IS USED, THE AMOUNT OF COAL REQUIRED BY THE STEAM GENERATOR IS MORE. THUS MILL CAPACITY IN TERMS OF HEAT INPUT TO STEAM GENERATOR DECREASES. The indications of mill overloading are the following, out of which one or more indication may be present during mill overloaded condition: a) b) c) d)

High mill motor current. High bowl differential pressure. Low mill outlet temperature. Mill rejects having large amount of coal.

3.5 START - UP: Before the pulveriser motor circuit is energized and the pulveriser is run under power for

taking

up

coal

firing.

The

following

completion/readiness. 1. Pre – Pre – Start Start up checks: a)

Pulveriser / motor coupling alignment.

b)

Roll ring clearance.

items

must

be

checked

for

Bowl Mill

3.0.

OPERATION

XRP1103

to a temperature range of 60 C to 70  C and exact temperature set point to be established later, depending upon operating experience with the given coal. 6.

Establish the required ignition energy. Then start the feeder with a fairly high feed rate. When the pulveriser begins to grind, (this is indicated by an increase in the motor amperes.) reduce the feed rate to the desired setting. Increase the feed rate as per unit load demand. The second and successive mills should be placed in service when the loading on the t he operating pulveriser(s) reaches 80%.

3.6

NORMAL SHUT DOWN: If possible cool the mill before shutting it down. i)

Close the mill hot air regulator damper and hot air shut off gate and cold air damper should be opened to maintain 100 percent air flow.

ii)

Continue feeding coal till the mill outlet temperature reaches 50 C. Then stop the feeder.

iii)

Run the mill for another few minutes till it becomes empty and then shut

Bowl Mill

3.0.

OPERATION

XRP1103

An emergency trip may subject residual fuel in the mills to cause spontaneous combustion. The unit should be re-fired within a reasonable time (45 minutes) to clear the mills. If this cannot be done, the mill should be cooled and manually cleared (see CAUTION). As a minimum precaution, the mill should be isolated, and all inspection doors removed / opened to prevent volatile gases from mill entering the furnace.

NOTE: If an inerting system is installed, start the mill steam inerting system for one minute immediately after shut down and again before opening the pulveriser inspection doors. The inerting steam line isolation valves must be properly closed before the mill manhole doors are opened.

CAUTION A HOT MILL WILL DISTILL COMBUSTIBLE GASES, FROM RESIDUAL COAL. THEREFORE TAKE PRECAUTIONS WHEN OPENING THE MILL FOR CLEANING.

Bowl Mill

3.0.

vi)

OPERATION

XRP1103

Repeat (ii) to (VI) above for all mills containing coal. When mills have been emptied and/ or placed back in service, the discharge valves of remaining idle mills should be opened to allow the required minimum cold air flow through them.

3.9

MILL FIRES: Causes: The usual causes of pulveriser fires are: i)

Excessive Mill Outlet Temperatures: Do not permit the mill outlet temperature to exceed 95 C regardless of the material being pulverised.

ii)

Foreign Material such as Paper, Bags, Straw, Wood and Excelsior collection in the inner Cone and other points in the Mill: These materials do not pulverise readily and therefore should be kept out of the raw fuel supply. When they get into the system, they collect and may catch fire. Each time the mill is opened for any reason, remove any such debris from air inlet, inner cone, bowl or other areas.

Bowl Mill

3.0.

OPERATION

XRP1103

must initiate the trouble. For instance, if a mill is operated with low air flow, higher mill inlet temperatures are necessary to maintain the set outlet temperatures. The air flow may be so low that additional coal settles out of the air stream. This condition can result in more heat, less coal movement and a potential for fire.

Another example would be failure to close the hot air gate when there is reason to believe an operating condition may have allowed a fire to start. Such a condition could be a sluggish damper drive mechanism or a sluggish damper control system, coupled with a substantial and rapid change in coal moisture.

An example of unusual operation would be running coal through a mill from a bunker that is known to be on fire. Of course extreme care must be taken while doing this. Everything possible must be done to make feeding continuous at a moderate to heavy rate.

Bowl Mill

3.0.

c)

OPERATION

XRP1103

Place the feeder on manual control and continue feeding coal at a high rate without overloading the mill.

Closing the hot air gate will frequently extinguish the fire, but if the mill temperature continues to rise:

d)

Stop the feeder as well as supply of Cold air to Mill and cool the mill by admitting steam or water.

NOTE : On pressurised mill where the air ducts and mill feeders are sealed, it is recommended that spray nozzles be installed in the mixing air ducts and mill center feed pipe so they may be used to admit water or steam to the milling system. The nozzles can be permanently piped to a supply system with suitable valves or they can be equipped with some type of quick disconnect coupling to allow connection to portable water supply hoses.

CAUTION FIRES UNDER THE BOWL USUALLY DO NOT CONTRIBUTE TO ABOVE BOWL FIRES OR EXPLOSIONS UNLESS SOMETHING IS ALLOWED TO VIOLENTLY DISPERSE THEM, SUCH AS A SUDDEN SLUG OF WATER. THE MOST EFFECTIVE WAY OF TREATING THEM IS TO CONTINUE RUNNING THE MI LL WITH COLD AIR UNTIL THE FIRE

Bowl Mill

3.0.

i)

OPERATION

XRP1103

Maintain a flow of cold air through the mill until all evidence of fire has disappeared and the mill is cold.

j)

Shut down and isolate the mill.

k)

Open all inspection doors (see WARNING) and hand hole covers.

l)

Inspect the mill interior and check the separator body, inner cone, upper and lower mill sides and feeder.

m)

NOTE:

Clean where necessary.

After any fire or mill puff, the entire milling system from the feeder to the fuel nozzles, including the coal feeder mill air inlet duct, coal pipes, internal coal nozzles and tilt mechanism should be checked for possible damage and cleanliness. Repeat the checks and be sure to remove any accumulations

Bowl Mill

3.0.

OPERATION

XRP1103

iron spout to pyrite hopper, from where they are periodically removed. Any material having a bulk density above 1.7 tons/ m3 should be rejected. (For coal bulk density is 1.2 TO 1.6 t/ m 3) However sometimes the raw coal is also rejected. This could happen due to:

i)

Over loading of mill.

ii)

Improper operation and adjustments.

iii)

Worn out parts.

i)

Over loading of Mill can be due to:

a) Mill capacity reduction due to low grindability index of raw coal, high fineness, high moisture. b) Physical overloading of mill due to feeder problems. (Refer feeder supplier’s manual)

ii)

Improper Operation and Adjustments:

Bowl Mill

4.0

4.0

PULVERISER LUBE OIL SYSTEM

XRP1103


GENERAL: The Pulveriser gear box (planetary) is completely lubricated from the external lube oil system. The Pulveriser lube oil system and piping is constructed so that oil can be circulated to the planetary gear and its bearings at the required location and flow back to the lube oil tank while the mill is in operation. The journal assembly is filled with oil and internal circulation takes place as the roller assembly rotates around its axis when the mill is in operation and loaded. Recommended lubricant specifications are given in the lubrication schedule in this chapter. 4.1

JOURNAL

The Roller Journals are lubricated by means of a self-contained circulation system. The oil level in the shaft is maintained at a point just below the top of the seal and checked by using a dip stick.

Bowl Mill

4.0


XRP1103

If no leakage is observed (indicating that the oil seals have seated properly) a normal interval of inspection, at least once in every three months and/ or when the opportunity presents itself, can be initiated. When checked, if the oil shown signs of contamination, or a laboratory test indicates oil break down, it should be changed.

To change oil, siphon out the old oil and add new oil to bring the oil back up to 4.2

the level. Do this repeatedly until the oil is clear.

MISCELLANEOUS & IDLE MILLS:

The Deflector Regulators and Journal Stop Bolts should be greased as per recommended Bowl Mill Lubrication schedule.

The Mill to Motor Coupling should be lubricated according to the manufacturer’s recommendations (given in the lubrication schedule).

Bowl Mill

4.0


XRP1103

BOWL MILL OIL COOLER - COOLING WATER REQUIREMENT PER MILL IN LITERS / MINUTE AT 32°C WATER TEMPERATURE

Recommended Inlet Pressure

:

4.5 Kg/cm2.

Pressure Drop in Cooler

:

Water quantity per cooler

:

0.7 Kg/cm2.

20 m3/hr.

ROLLER JOURNALS OIL QUANTITY AND LEVELS:

MILL SIZE

Quantity of lubricant

Quantity of lubricant

Oil level (in mm)

per assembly (in liters)

per mill (in liters)

from bottom

85

255

810-910

XRP- 1103

GEAR CASE OIL QUANTITY:

Mill Size

Quantity of lubricant per mill

Bowl Mill

4.0


XRP1103

4.3 PULVERISER LUBE OIL SYSTEM OPERATING INSTRUCTIONS GENERAL CONFIGURATION

The oil supply system described below is used for oil cooling and/or lubrication of a gear unit (see Vendor’s “O&M Manual of Lube Oil System”). The oil supply system has been subjected to an exhaustive trial run. The oil supply is ensured by means of two pump assemblies, one of which acts as a standby pump. The pump draws the oil from the oil reservoir of the oil supply system.

A filter is provided in the oil circuit for filtration of the circulating oil. The quantity of heat generated by losses, which is not dissipatable by convection, is dissipated by means of a cooler. Filtered and re-cooled oil is then passed back to the gear unit via a pressure line. The modules described above are mounted on the oil reservoir of the oil supply system.

4.3 1. FILLING WITH OIL

Bowl Mill

4.0


XRP1103

oil. If the flushing oil is to be used in another system, it should first be carefully purified/ filtered.

Fresh oil in accordance with the specification should be used for startup (see operating instructions “Planetary Gear box” Section-5).

Fill the oil supply system tank with oil in accordance with the Operating Instructions ”Planetary Gear box”- Section-5.

Fill until the specified oil level is reached on the oil level gauge with the pump stationary (see Operating Instructions “Planetary Gear box”- Section-5). The pump should then be started.

Before initial startup of the gear unit, the oil supply system must be run for at least 15 minutes to allow all oil compartments to fill up (see Operating Instructions “Planetary Gear box”- Section-5). Stop the oil supply system again afterwards and correct the oil level if necessary.

Bowl Mill

4.0


XRP1103

Before starting up the oil supply system, check that the requirements in accordance with these Operating Instructions and the requirements in accordance with the gear unit Operating Instructions have been fulfilled.

CAUTION 1.0 Before startup, filling with oil must be carried out. 2.0 Before startup, check the cooling water circuit! 3.0 Stop valves are to be secured to prevent accidental cl osure.

Before startup and after repairs and maintenance work, the oil supply system is to be cleaned thoroughly to remove any impurities. This applies particularly to water (e.g. rain water and leakage of the cooler) in order to prevent mixture of water and oil. All pumps, filters and coolers must be suitably bled.

NOTE: The works setting of the pressure relief valves/safety valves carried out at works may NOT be altered, as it is not used to regulate the pressure and rate of

Bowl Mill

4.0


XRP1103

a) One on the oil tank (HVA CT 502). b) One each at the cooler outlet & inlet (HVA CT500, 501). 4.4.2 PRESSURE MEASUREMENT: -

Two Pressure Switches (HVA CP101, CP102) are provided in the lube oil line, after the oil cooler assembly.

-

A differential pressure switch (HVA CP100) is provided across the oil filter unit for alarm. A differential pressure indicator (local- HVA CP503) is also provided.

-

Pressure indicators are provideda) One each at the filter inlet and outlet (HVA CP500, CP502). b) One at the cooler outlet (HVA CP501).

4.4.3 LEVEL MEASUREMENT: -

Two oil level Switches (HVA CL100, CL101), one for high level alarms and the other for low level (pump trip), are provided in the oil tank. One oil level gauge (HVA CL500) is provided on the oil tank for visual check of “OIL LEVEL”.

Bowl Mill

4.0


XRP1103

4.6 PLOS OPERATION: Once the lube oil system flushing along with the gear box is completed the same is declared ready for normal operation. When the oil temperature in the tank (HVA CT103) is greater than 10 deg. C the lube oil pump is permitted to start and at oil temperature value greater than 30 deg. C at the cooler outlet (HVA CT100) the mill is released for start. Below 30 deg. C oil temperature in the tank (HVA CT104) the oil heater (HVA AH001) is energized, provided the pump is in service. The heater is de-energised at the tank oil temperature (HVA CT105) of 36 deg.C or when the lube oil pump is stopped. Charge one of the duplex filters and the oil cooler. Once the permissive conditions are met with, start the lube oil pump. The lube oil pump can be started either from Local push button OR from FSSS through a potential free contact & CRT and when pump stop command is not present, lube oil level is not low (HVA CL101) and tank oil temperature is not low (HVA CT103). The filter change over can be done on line for cleaning the filter element. Cooler change over can be done on line too. 4.7 MILL START PERMISSIVE CONDITIONS FROM THE PLOS: THE MILL MOTOR CAN BE ENERGISED ONCE THE FOLLOWING PERMISSIVE CONDITIONS ARE FULL FILLED.

Bowl Mill

4.0


XRP1103

4.9 PUMP TRIP CONDITIONS: The lube oil pump stops/ shall be stopped when any one of the following conditions are acknowledged or satisfied. a) Lube oil level in tank is low (HVA CL101). b) Lube oil temperature in tank is low ( HVA CT103 < 10 deg. C) c) Pulveriser OFF for more than 60 minutes and pump stop push bottom actuated. 4.10 STAND-BY PUMP START CONDITIONS: a) The running pump is ‘ON’ for more than 60 seconds and discharge pressure at pump outlet is low (HVA CP101< 0.8 bar), the standby pump to start. b) When Pump-1 (Main) fails to start on giving start command, after 10 sec. time delay, the stand by pump to start. c) The running pump trips on fault, the stand-by pump to start immediately. 4.11 OUTPUT CONTACTS PROVIDED: a) b) c) d)

Pulveriser Start Permissive ( to FSSS) Pulveriser Stop Command ( to FSSS) Start lube oil pump (to motor starter) Stop lube oil pump (to motor starter)

Bowl Mill


LUBRICATION SCHEDULE

XRP1103

EQUIPMENT: BOWL MILL XRP 1103 TABLE -1

Recommended Lubricants

Sl. No.

Parts to be Lubricated

1

2

3

1

Mill Drive Gear Housing

Servomesh SP-320

Parthan EP-320

AMOCAM OIL-320

External tank

2

Roller Journals

Servomesh SP-680

Parthan EP-680

AMOCAM 680

Reservoir cap on journal shaft

255

Journal Stop Bolts Discharge valve shafts and Seals Journal Shaft Oil Seals Mill Drive Motor Drive Coupling ( Grid-Disc) Drive oupling ( if GridGear)

Servogem3

Lithon-3

MP Grease3

Grease fitting

Fill chamber initially. Lubricate after making adjustments.

Servogem3

Lithon-3

MP Grease3

Grease fitting

Grease the shafts and seals initially and every 2 weeks.

3

4

5 6

7

8

IOC

HP

BP 4

5

Type of filling

Qty. of Lub. In litres/Mill

Frequency of oilcheck

Frequency of observation

6

7

8

9

Molykote 33 or equivalent

1600

6 Months

Once daily check gauges, lines and headers

6 months

Check when accessible at least once in every 3 months

Grease the shafts and seals initially and every replacement time.

Remarks 10 Oil level shall be maintained in the external lube oil tank Level 810 mm to 910 mm

Wipe clean all grease fittings before and after greasing. Remove excess grease

As per Motor Manufacture's Recommendation Not Required at Disc End ServoGem-3/HTXX of IOC at Grid End

Pack completely initially & Every Three months. Clean Out & Renew the Grease Every three months.

ServoGem HTXX of IOC at Gear End & Grid End

Pack completely initially & Every Three months for grid end. Clean Out & Renew the Grease 15 days at Gear end.

BHARAT HEAVY ELECTRICALS LIMITED

14

5.0.

PLANETARY GEAR BOX

Bowl Mill XRP1103

5.0 PLANETARY GEAR BOX 5.1 PLANETARY GEAR BOX OPERATING INSTRUCTIONS 5.1.1

MEASURES AND CHECKS BEFORE START UP

Measures before startup Warranty shall only be given if the initial startup was carried out by BHEL specialists or by specialists of the plant engineer after prior consultation with BHEL. Note: Any attempt to make the drive move will be regarded as startup! Especially in case of maintenance work on the mill where the mill is rotated and the gear unit rotates, too, the Operating Instructions should be observed.

Checks before startup After the assembly and before the first cold dry run, check all drive parts and remove all residues of material, tools and assembly aids. The oil supply system function is tested before delivery. Before the dry run of the

5.0.

-

PLANETARY GEAR BOX

Bowl Mill XRP1103

Are the pipes and tubes mounted and arranged correctly? CAUTION MAKE ABSOLUTELY SURE THAT THE OIL FEED PIPES ARE CLEAN AS ANY CONTAMINATIONS IN THE PIPES WOULD BE LED THROUGH THE GEAR UNIT BEFORE THEY CAN BE CAUGHT IN THE FILTER OF THE OIL SUPPLY SYSTEM, RESULTING IN BEARING DAMAGE

- Were the pipe and tube connections checked for leaks? Pay special attention to the flange connections of the suction pipe. When air enters, the oil tends to foam. - Does the oil in the oil container (tank of the oil supply system or the gear unit, respectively) show little foam on the surface? A thin layer of foam of appr ox. 3 ... 4 mm (0.12 – 0.16 inch) on the surface is permissible. When foam develops, check all suction pipe connections. If necessary, contact the manufacturer of the oil. - Is the oil container filled with oil up to the respective marks? - Is the pad bearing filled with oil up to the mark? - The oil level may be checked while the oil supply system is running and the gear unit is stationary.

5.0.

5.1.3

Bowl Mill

PLANETARY GEAR BOX

XRP1103

FLUSHING General A clear difference must be made between ”flushing” before the initial startup and ”flushing” before/ after repair and maintenance work.

Flushing before the initial startup The purpose of flushing before the initial startup is to minimize the residues of previously used lubricating oils or preservative oils. The selected operating lubricating oil shall be used for flushing. -

Put in selected lubricating oil.

- Flushing times: run the oil pump of the lubrication circuit for 6 hours at least for flushing or the filter is found on visual inspection reasonably clean, whichever occurs later.

CAUTION AFTER FLUSHING, DRAIN THE OIL COMPLETELY THROUGH THE OIL DRAIN COCKS ON THE GEAR UNIT AND THE OIL SUPPLY SYSTEM. THE OIL MAY ONLY BE RE-USED AS

5.0.

PLANETARY GEAR BOX

PLANETARY GEAR BOX ASSEMBLY

CAUTION

Bowl Mill XRP1103

5.0.

PLANETARY GEAR BOX

Bowl Mill XRP1103

- The oil supply system is equipped with a tank and the oil is to be filled-in through the oil tank of the oil supply system.

5.1.4.2 Oil quantity

a)

Oil quantity for flushing For flushing, the gear unit & piping the tank of the oil supply system should be filled with just sufficient quantity of oil to run the oil pump of the oil supply system for this purpose. Depending on the gear unit, this oil quantity can be between 50 % and 60 % of the total oil filling quantity.

b) Oil quantity for the initial startup Fill in so much oil that the prescribed oil level is reached on the oil level indicators of the gear unit (see cross section drawing-FIG A) and the oil supply system tank with the gear unit stationary and the oil pump of the oil supply system running. After the pre-run of the oil supply system (see Section 4.7), the gear unit can

5.0.

PLANETARY GEAR BOX

Bowl Mill XRP1103

During this phase, pay special attention to the following: 

Noises If possible, check the gear unit for abnormal noises (anti-friction bearings) with a stethoscope in different places during this time.



Oil leakages Check all flange connections of the oil pipes for oil leakages and re-seal them, if necessary!



5.1.6

Measure the vibration at the gear box input shaft end SHUT-DOWN -

Switch off the drive assembly to shut down the gear unit. It is recommended to let the oil supply system run during short interruptions of operation. For a longer standstill, we recommend to let the oil supply run for approximately 60 minutes to prevent heat from building up. However in case of sudden standstill, e. g. due to a power failure, there i s no danger of damage.

CAUTION SECURE THE DRIVE ASSEMBLY TO PREVENT ACCIDENTAL SWITCH-ON!

5.0.

PLANETARY GEAR BOX

Bowl Mill XRP1103

- Correct oil level (see also Section “Startup”). Note:

To check the oil level, the gear unit should be shut off and the oil pump of the lubrication circuit of the oil supply system should be running.

The oil level should be between the two marks on the oil level indicator. If the oil level is below the lower mark of the oil level indicator, top up oil if necessary. CAUTION IF IRREGULARITIES ARE DETECTED DURING OPERATION OR IF A PRESSURE TRANSMITTER, A TEMPERATURE TRANSMITTER OR A VOLUMETRIC FLOW TRANSMITTER IN THE OIL SUPPLY SYSTEM INITIATES AN ALARM AND LATER ON A TRIP SIGNAL, THE DRIVE ASSEMBLY SHOULD BE SHUT OFF IMMEDIATELY.

Control information: See Section 4.4, “PLOS Operating Procedure” for control information. 5.3 GENERAL TROUBLESHOOTING The Trouble Shooting Table lists possible malfunctions, their causes and

suggestions

for remedying them. If the cause cannot be determined or there is no facility for repair with suitable own equipment, it is recommended calling in BHEL for service fitters.

5.0.

Bowl Mill

PLANETARY GEAR BOX

Defective cooler Defective cooling water

Gear unit oiled up

Pressure control trips alarm

meter trips alarm Temperature at temperature sensor in pad bearing (part

Observe operating instructions for Cooler.

supply

Check cooling water supply. Observe Operating Instructions for cooler.

Insufficient sealing of the housing Cover or the joints.

Check seals, replace if necessary. Seal joints.

Breather assembly clogged

Clean it

Oil temperature is < 300C

Heat the Oil

Oil level too low in tank Operating temperature too high

Pipes leaking

Check oil level, top up oil if necessary See above-“Excessive Operating Temperature” Clean oil filter, Observe Operating Instructions for oil Filter. Warm up oil Clean oil filter Observe Operating Instructions for oil filter Check pipes, replace if necessary

Oil filter clogged Oil level of pad bearing housing is too low Monitoring devices

Check oil filter for clogging Check the setting of the pump/ system relief valves. Check all monitoring devices.

Oil filter clogged Volumetric flow

XRP1103

Oil too cold Oil filter clogged

5.0.

5.4

Bowl Mill

PLANETARY GEAR BOX

XRP1103

INSPECTION The inspection comprises all measures to determine and evaluate the actual condition. It is recommended to use a check list. A suggested check list is given below: TABLE-2 (Check list for evaluating the condition of PGB lube oil system)

Measures General visual check for cracks, leaks & damages Visual check of the flank condition for damage Check the oil filter of the oil supply system for clogging.

Frequency/ Periods Every 4 weeks

Remarks

Every 4 weeks every 4 weeks

visual indication, see also Operating Instructions for oil supply system.

5.0.

5.5

Bowl Mill

PLANETARY GEAR BOX

XRP1103

MAINTENANCE a) Maintenance Measures:

Measures

Frequency/Periods

Remarks

Clearing the filter elements

Every 4 weeks or when

See operating instructions

filters are dirty

for individual components

Testing

oil

for

water

content

First time after approx. 400 operating

hours’

then

See item 5.5.1

once per year atleast First

&

subsequent

oil

Depending on analysis of

See item 5.5.1 (b)

change after start-up

oil carried out

Oil analysis

Every 1000 operating hours

See item 5.5.1

Subsequent oil changes

Depending on result of oil

See item 5.5.1(b)

analysis;

(without

oil

analysis every 18 months or 60000 operating hours) Checking of air filter

Every 12 weeks

See item 5.5.1(c)

5.0.

b)

Bowl Mill

PLANETARY GEAR BOX

XRP1103

Examining oil for water content / making of oil analysis

Detail information on examining the oil for water content or on making of oil analysis can be obtained from the lubricant manufacturer or from BHEL service department. - The oil sample for an oil analysis has to be taken downstream the gearbox in the drain line of the lubrication system while the system is running. A suitable connection can be provided on the oil drain piping (for example an oil drain line with isolation valve and end plug). - The minimum amount required is 1 liter of oil in a clean and for transportation purposes closeable safety vessel. - The decrease in oil viscosity should not exceed 10% of the value of the new oil. -

Oil purity must be between 15/13/10 (high availability) and 17/15/12 (normal availability) according to ISO 4406.

Limit values for oil contamination: Material Iron

(Fe)

Limit content

possible source

[ mg/kg ] 40

Internally toothed gear, cage of a bearing

5.0.

Bowl Mill

PLANETARY GEAR BOX

XRP1103

CAUTION WHEN CHANGING THE OIL, THE GEAR UNIT SHOULD ALWAYS BE FILLED WITH THE OIL GRADE PREVIOUSLY IN USE.

When changing the oil, the gear housing and the lube oil system must also be cleaned thoroughly by flushing with oil to remove oil sludge, abraded particles and residue of old oil. For this purpose, the same oil grade should be used as is in use for operation of the gear unit. Viscous V iscous oils should be warmed beforehand. Only when all residues have been removed, shall the fresh oil be poured in.

Note:

The oil should be changed directly after shutting off the gear unit while the oil is still warm. -

Shut down the gear unit by switching off the drive unit.

CAUTION SECURE THE DRIVE UNIT TO PREVENT ACCIDENTAL STARTUP

5.0.

PLANETARY GEAR BOX

Bowl Mill XRP1103

Detailed illustrations of the gear unit will be found in the drawings in the gear unit documentation.

Note:

Dispose-off the old old oil according to the regulations on environmental protection. protection.

CAUTION THERE IS A RISK OF SCALDING FROM THE HOT OIL EMERGING. WEAR PROTECTIVE

5.0.

Bowl Mill

PLANETARY GEAR BOX

XRP1103

CAUTION ANY OIL LEAKAGE SHOULD BE REMOVED IMMEDIATELY WITH OIL BINDING AGENT. . d)

CLEANING THE AIR FILTER 

Every 12 weeks or when the air filter (breathing filter) is clogged, heavily.



Unthread the filter and clean it with petroleum benzine or similar detergents. CAUTION

BE EXTREMELY CAREFUL WHEN CLEANING WITH COMPRESSED AIR. WEAR SAFETY GLASSES!



e)

Reinstall the dry air filter.

CHECKING THE BINDING BOLTS FOR TIGHTNESS

All binding bolts with metric thread according to DIN 13, sheet 20, of pr operty class 5.8 according to DIN 267 should be tightened to the following pre-stressing forces.

5.0.

f)

Bowl Mill

PLANETARY GEAR BOX

XRP1103

CHECKING THE BINDING BOLTS FOR TIGHTNESS

All binding bolts with metric thread according to DIN 13, sheet 20, of pr operty class 5.8 according to DIN 267 should be tightened to the following pre-stressing forces.

Thread size

Prestressing Force (in Newton)

Prestressing Force ( in Lbf)

Tigtening Torque ( In N-m)

M 20

71250

16017

256

189

M 24

102500

23042

443

327

M 30

163750

36811

906

668

M 36

238750

53671

1580

1165

M 42

328750

73903

2540

1873

M 48

433120

97365

3830

2825

M 56

599370

134738

6150

4536

Tightening Torque ( in Lbft)

Pre-stressing Device ( In Bar)

See the Operating Instructions of

5.0.

g)

Bowl Mill

PLANETARY GEAR BOX

XRP1103

COMPLETE GEAR UNIT INSPECTION The gear unit inspection should be entrusted to BHEL Service Division as by virtue of vast experience, technicians can most reliably assess whether and which part of the gear unit need to be replaced.

Maintenance comprises all measures to maintain the desired condition.

Measures Cleaning the filter inserts Test oil for water content First oil change after start – up Oil analyses subsequent oil changes

Frequency Every 4 weeks or if filter element is dirty. after approx. 400 service hours /at least once a year after approx. 1000 service hours or depending on result of oil analysis every 1000 service hours depending on result of oil analysis; (without oil analysis every 18 months or 60000 operating hours)

Remarks see Operating Instructions for the individual components see item 5.5.1 see item 5.5.1(b) see item 5.5.1 see item 5.5.1(b)

5.0.

5.6

PLANETARY GEAR BOX

Bowl Mill XRP1103

REPAIR Repair comprises all measures to re-establish the desired condition after a malfunction.

CAUTION WHEN CARRYING OUT REPAIR WORK USING ELECTRIC WELDING AT ANY POINTS OF THE UNIT, MAKE SURE THAT THE WELDING CURRENT IS NOT CONDUCTED THROUGH ANTI-FRICTION BEARINGS OR OTHER MOVING CONNECTIONS AND MEASURING DEVICES. THEREFORE, THE WELDING CURRENT RETURN CABLE SHOULD BE DIRECTLY CONNECTED TO THE PART TO BE WELDED.

When replacing components and larger sub-assemblies, make sure that they are fastened and secured carefully to hoists to avoid hazardous situations.

CAUTION ONLY USE SUITABLE HOISTS IN PERFECT TECHNICAL CONDITION AND SUSPENSION DEVICES WITH SUFFICIENT CARRYING CAPACITY! DO NOT STAND OR WORK BELOW SUSPENDED LOADS

5.7

LUBRICANTS

5.0.

Bowl Mill

PLANETARY GEAR BOX

XRP1103

TABLE - 6 QUANTITY

DESCRIPTION

PARTNO.

MANU FACTU RER

TAG. NO.

Temperature element Duplex PT100 Resistance thermometer EL =280 mm HFC01 CT020 Connection : G ½ A HFC01 CT021 4 Precision resistor : Double PT 100 DIN 800 BHEL HFC01 CT022 IEC 60751 HFC01 CT023 Four-wire circuit from Terminal box Degree of protection : IP 65 > 75 °C : WARNING > 85 °C : MILL STOP Temperature control of the rolling bearings Temper “x” is adjusted to: Actual temperature (after approx.. 100 Operational hours) +15 K: WARNING +20 K: MILL STOP However, not above 1000C x1 = T(act) + 15 K= ….,x2 = T (act) +20 K Temperature element

5.0.

PLANETARY GEAR BOX

Temperature of pad bearing (800)

Bowl Mill XRP1103

< 75 °C

Temperature of bearings (806 / 808) < x1 °C

A warning should be output if one of the following conditions is met:

Temperature of pad bearing (800) > 75 °C Temperature of bearings (806 / 808) > x1 °C

The mill motor should be stopped if one of the following conditions is met:

Temperature of pad bearing (800) > 85 °C Temperature of bearings (806 / 808) > x2 °C

CAUTION AFTER SWITCHING OFF THE GEAR UNIT, THE OIL SUPPLY SYSTEM SHOULD TO BE IN SERVICE, AT LEAST FOR ANOTHER HOUR TO AVOID THE ACCUMULATION OF HEAT.

5.0.

Bowl Mill

PLANETARY GEAR BOX

XRP1103

Please note that special production and supply specifications frequently exist for individual components and that BHEL always supply replacement parts in accordance with the state of the art and the latest legal requirements.

The relevant data should be stated when ordering replacement parts: SPARE PARTS LIST-KMP 350 PART NO

DESCRIPTION

QTY

WEIGHT(Kg)

0318

PLUG

1St

0.4

0040

Oil level Indicator

1 St

0.2

0045

Ball Cock

1 St

1.4

0046

Ball Cock

1 St

1.4

0056

Air Filter

2St

0.1

0099

Pair Of Mating Bevel Wheels

1 St

1105.0

0100X

Bevel Pinion Shaft

1 St

170

0402X

Bevel Gear

1 St

722

5.0.

PART NO

Bowl Mill

PLANETARY GEAR BOX

XRP1103

DESCRIPTION

QTY

WEIGHT(Kg)

0302

Gear Wheel

3 St

162.0

0350

Rolling Contact Bearing

3St

61.0

0400

Shaft 195x555 1.6587

1 St

110.0

0390

Coupling Sleeve

1 St

25.0

0428

Shim Ring, 2-Piece

1 St

7.0

0450

Paired Taper Roller Bearings

1 St

29.4

0451

Rolling Contact Bearing

1 St

11.7

0800

Resistance Thermometer EL=265

4St

0.3

0806


1 St

0.1

0808


1 St

0.2

X Parts

belongs to the sub assembly. Hence the sub assembly must be replaced complete. TABLE – 7

6.0.

6.0

MILL OPTIMIZATION

Bowl Mill XRP1103

MILL OPTIMIZATION

PURPOSE:

The purpose of this program is to optimize the mill operation to ensure the rated mill capacity with required PF fineness and at the same time, the best wear life of grinding elements and other wear prone areas is achieved.

ADJUSTMENTS:

One or more of the following adjustments may be required for the mill optimization:

1)

Area of opening around the bowl for primary air flow to maintain desired differential pressure across the bowl, with low mill rejects.

2)

Vary the journal spring compression value to achieve the required mill output, fineness and mill rejection level.

6.0.

MILL OPTIMIZATION

Bowl Mill XRP1103

Procedure:

1)

Collect one set of mill readings from Unit Control Room (UCB), raw coal analysis data, Pulverised fuel fineness details, quantity and quality of mill rejects and raw coal size and grindability index etc.

2)

Check and ensure the requirements of raw coal feeder, condition of mill DP instruments, and primary air flow through the mill and the quantity of raw coal.

The above adjustments may be carried out to maintain the required bowl DP, PF fineness, quantity & quality of mill rejects and for the said purpose.

7.0

TROUBLESHOOTING

Bowl Mill XRP1103

7.0 TROUBLESHOOTING The trouble shooting guide lists Mill Malfunctions generally faced but a large number of the problems are off shoot of a problem, which has not been take care in time. Mill problems can be reduced to maximum extent if the Instructions are listed here are followed. If the malfunction is not clear, we recommend therefore that the specialist personnel of BHEL be consulted in tracing possible cause.

Instructions:1. Maintain proper air flow and mill outlet temperature 2. Do not run the mill with spillage. 3. Change or service labyrinth seal as soon as it fails. 4. Prevent foreign material entry to mill with coal. 5. Check and maintain proper internal clearances regularly. 6. Follow the lubrication chart/schedule. 7. Empty the pyrite hopper periodically.

Bowl Mill

TROUBLESHOOTING

XRP1103

TABLE- 8 Disturbances, Reasons and Remedy Bowl Mill Troubleshooting Guidelines PROBLEM

Mill Vibration Under Load

PROBLEM CAUSE Spring Compression too high Improper assembly of Bull Ring segments Excessive wear of Bowl and extension ring Loosening of Separator body bolts Roll to Bowl clearance

RECOMMENDATION Reset Spring compression Assemble Properly Replace Extension Ring. Build up bowl by weld deposit Tighten the Separator body bolts. Adjust roll to bowl clearance.

Foreign material in mill

Take mill offline and remove foreign material

Over feeding Insufficient primary air flow

Reduce feeder speed/ coal feed to mill Correct the primary air flow quantity. Attend to worn out seal air skirts. Service the bearings and oil seals Check and clean seal air supply to journal assembly. Reduce Cold air, increase hot air supply. Reduce feeder speed. Replace roll/or Ring and adjustment. Increase spring pressure load. Reset classifier Blades towards open position. Reset the classifier towards open position. Reset to the required pressure load.

Jamming of rolls Mill Coal spillage High

High Pulverized fuel fineness

Low Pulverized Fuel Fineness

Low Mill outlet temperature Worn grinding roll Low journal spring Pressure set Classifier set for higher fineness Improper setting of classifier Excess spring compression Improper Method adopted for : i. Pulverized Fuel sampling technique ii. Sieve Analysis Improper setting of classifier Improper Alignment of classifier vanes High air Flow

Train the manpower. Reset classifier Blades towards closure position(max position “5”). Properly align classifier vanes Repair/ Replace Worn out Parts.

Table 8(cont.) BHARAT HEAVY ELECTRICALS LIMITED

39

Bowl Mill

TROUBLESHOOTING

XRP1103

Table 8 (cont.)

Low Pulverized Fuel Fineness (cont.)

Oil Leakage from Flanges

Lubricating Oil Temp. too High Lubricating Oil Temp. too Low

Lubricating Oil header pressure too Low

Reduce air flow to design value. More gap between cone and feed pipe More gap between inverted cone and classifier cone. Improper setting of:i. Ring Roll clearance ii. Pressure spring seat- journal head clearance Mating surface not cleaned properly. Seal compound not applied Improper gasket used

Excess wear of mill parts Correct the gap. Correct the gap.

Assemble properly. Apply Gasket eliminator or any suitable sealing compound. Use compressed asbestos gasket.

Bolts not properly tightened, threads damage

Tighten properly. Rethread to mark high size bolt.

No cooling water Cooler contains air

Rectify cooling water supply. Bleed cooler.

Cooler dirty

Replace Cooler,/ Clean or Replace contaminated pipe bundle.

Gear unit not yet warmed up to operating temperature. Too much cooling water Filter Clogged Pressure limiting valves defective/wrong set Suction line blocked Pump Aspirating air Lubricating oil temperature too High Oil Viscosity too low

Check whether heaters are working Reduce cooling water supply. Switch over to clean filter and clean filter and clean filter element. Replace Pressure limiting valve if defective. Clean suction line. Check suction line and remedy any leaks. Check cooler performance. Check viscosity and if necessary fill with correct oil.

NOTE: Also refer to Sec: 5 on Planetary Gear Box BHARAT HEAVY ELECTRICALS LIMITED

40

Bowl Mill

TROUBLESHOOTING

Lubricating oil pressure too high

Gear unit not yet warmed up to operating temperature Pressure limiting valve wrongly set Pressure limiting valve defective Lubricating oil lines to and at gear unit blocked High Mill outlet Temperature

Mill Fire

Journal Oil Contamination

Coal settlement in mill Rapid change in moisture content of coal Putting burning coal in mill Bearing damaged Oil contaminated improper oil No Bearing clearance Oil seal damage/ worn out wear sleeve Pipes dirty(scale, welding residues)

Clearly appeared or accumulated filter residues

Abraded particles from gear unit Lubricating oil dirty Oil tank dirty


XRP1103

Wait, Reduce cooling water flow/ isolate. Correct oil pressure at limiting valve. Repair or replace pressure limiting valve Locate blocked line and clean. Do not exceed mill o/l temp. Recommend as per volatile matter content in coal. Do not leave coal in idle mill. Remove the coal either manually or taking the mill in service. Remove accumulated mill rejects from air duct and mill side housing, periodically. Keep a close watch at mill outlet temperature. Empty the bunker and remove smoldering coal. Change bearing. Change oil as per recommendations Set bearing clearance. Change them. Clean pipes. Check gear unit (bearing, tooth systems, alignment)and rectify defects. Carry out oil change. Clean oil tank and carry out oil change.

41

Bowl Mill

TROUBLESHOOTING

Interrupted coal flow

Check & take necessary action

Too high air flow, particularly hot air flow

Open cold air and reduce hit air keeping air flow to mill constant.

Fire in mill/ coal fed to mill

Check mill/feeder for fires See that coal flow is optimum(Bowl Differential, feeder speed, mill motor current) If this measure are not fr uitful and temperature continuous to rise, isolate mill & spray water t o quench fire.

High Mill outlet temperature

Oil consumption too high

XRP1103

Leak in pipes, connections, valves or gear unit. Cooler Leaking Shaft outlets on gear unit leaking

Tighten screws. Seal cooler or renew cooler element. Renew seal ring. Refer to BHEL-Pulv.Engg. division for solution.


42

8.0.

PULVERISED COAL SAMPLING

ANALYSIS & ADJUSTMENT OF FINENESS

8.0

Bowl Mill XRP1103

PULVERISED COAL SAMPLING:

Pulverised coal samples should be taken for fineness test periodically and whenever furnace or pulveriser operation suggests fineness has changed.

In order to obtain repeatable and comparable fineness test results, it is necessary to maintain the pulveriser and furnace conditions as constant as possible during the sampling procedure. The pulveriser should be on manual control at or near its full load rating and should be allowed to settle out for at least 10 minutes before testing starts, pulverisers with obvious indications of trouble (heavy coal spillage, rumbling) should not be tested. 8.1

NON-ISOKINETIC SAMPLING METHOD: (For ISO KENITIC SAMPLING refer to O& M manual of Vendor, if applicable)

A sampling device, illustrated in Figure – ‘O’ is supplied for each installation. The sampling device consists of a cyclone separator, a sampling jar (receiver) and a

8.0.



Bowl Mill XRP1103

sample should then be placed on the top screen of nest ed 50 mesh, 100 mesh and 200 mesh sieves. The sieves should be shaken on a Ro-tap or similar shaker for a total of 15 minutes. After 5 and 10 minutes stop the shaker, remove the collecting pan, brush the bottom of the 200 mesh sieve and discard the contents of the pan.

After 15 minutes the amount of coal left on each of the sieves is individually weighed and fineness is calculated as per the following example.

Sample Calculation

Example

% on 50 mesh ( 2 x Wt. on Sieve)

2 x 0.5 = 1.0%

% through 100 mesh

100 - 2 (0.5 + 4.4) = 90.2%

100 - 2 (Wt. on 50 + on 100)

% though 200 mesh

8.0.



Bowl Mill XRP1103

NOTE: Holes in the inner cone, holes in the deflector vanes or missing deflector vanes can produce erratic coal fineness test results. Check the calibration of air flow instrumentation if high air flow is suspected. Improper ring-roll setting, journal spring compression too would affect the P.F. fineness.

The following publications may be used as references for sampling and sieving procedures.

Sampling

:

A.S.ME. P.T.C. 4.2 ------ for non iso-kinetic method or ISO 9931 for ----------- Isokinetic sampling

Sieving 8.2

:

A.S.T.M.D. 197 “Test for Fineness of Powdered Coal”.

ADJUSTMENT OF FINENESS:

The degree of coal fineness obtainable with air separation is extremely high, and with in normal limits it is possible to control fineness with considerable exactness.

8.0.



Bowl Mill XRP1103

It should be remembered that with increasing fineness there is a decrease in the capacity of the pulveriser in tons per hour and an increase in the power required per ton of Pulverised coal.

The fineness is adjusted by moving the deflector handle(s) on the separator top. When the handle point is set on “0”, the deflector vanes are at their maximum opening , producing minimum fineness. As the handle is moved to higher numbers on the scale, the deflector blades close and fineness increases. See Figure –‘E’ for deflector blade set up. The fineness for which the pulverising equipment and system were designed is given in the contract. If the coal is finer than necessary when deflector handle point is set on “0”, the handle should be reset to allow for a greater blade opening. If deflector blades are radial and the fineness is still too high, then there is the possibility that the spring force on the journals should be reduced. If the coal is too coarse when the deflector handle point is set on “10”, the spring force may have to be increased.

8.0.



Bowl Mill XRP1103

8.0.



Bowl Mill XRP1103

8.0.



Bowl Mill XRP1103

8.3 MILL WEAR LIFE ASSESSEMENT The objective of this test is to realize the maximum wear life of grinding element. Attach wear measurement gauge to journal assy. It is important to hold the gauge securely against lower journal housing and roller back face to ensure accurate reading as shown in figure 8B

9.0.

Bowl Mill

MAINTENANCE

XRP1103

9.0. MAINTENANCE

The Bowl Mill and its auxiliaries require continuous monitoring and periodical maintenance to ensure reliable operation and availability. Monitoring and Maintenance are required both during operation and when the unit is at standstill. Some maintenance works require with the mill at shut down position, while some maintenance works may be carried out during normal operation of the mill. This Maintenance Section of O & M manual is divided into three sub-sections:-

MAINTENANCE

GENERAL

PREVENTIVE

COMPONENT MAINTENANCE

10.0 GENERAL MAINTENANCE

Bowl Mill XRP1103

10.0 GENERAL MAINTENANCE:

The pulveriser is a rugged machine, designed and built for continuous operation over an extended period, with minimal wear on the working parts. However iron pyrites and other abrasive substances in the coal are apt to shorten the l ife of parts such as the rolls, bull ring, rotating vanes and scrapers.

Since wear of pulveriser parts depends on many factors that vary from one installation to another, it is difficult to prescribe a specific routine inspection and maintenance program. Characteristics of the fuel, operating hours of individual pulverisers, availability of pulveriser due to unit load demands, and trained maintenance staff availability are all factors that determine the frequency and scheduling of pulveriser inspection and maintenance. An effective program can be established only on the basis of actual plant operating experience. It is therefore imperative that an accurate log be kept from the beginning, to relate individual pulveriser running time (see NOTE) with pulveriser performance, plant operating schedules, unit load, outages, inspection reports, and other


Bowl Mill XRP1103

Reduced pulveriser capacity and increased spillage even after carrying and ring roll setting periodically are indications of excessive wear requiring part replacement. Contour templates, made when the equipment is new, may aid in checking the degree and location of wear as it progresses. In case sand accumulation is noticed on the bowl which would also stop the mill output, carryout “Mill Purging” periodically. Stop coal feeding and air supply to mill and run it empty for 5 minutes till all the sand from bowl is removed by centrifugal action of the rotating bowl. II) Airport Ring (Figure. 11.d):

Check and maintain a vertical clearance of 5 to 11 mm between the top of rotating vanes and the bottom of the body liner segment. III) Bowl Extension Ring:

The ring should be replaced when worn excessively.

Bowl Mill


XRP1103

VII) Mill Discharge Valves:

Excessive clearance in valve flap closed position is an indication of wear. Disc should be replaced when worn out. Most of the inspection and repair works inside the pulveriser above the bowl can be accomplished by removing one journal assembly cover and journal assembly. Work below the bowl is normally done by entering the mill through the mill side access door.

CAUTION WHEN MAINTENANCE IS REQUIRED ON A PULVERISER WHILE THE UNIT IS IN OPERATION, MAKE SURE THE PULVERISER IS COMPLETELY ISOLATED (DAMPERS, GATES AND VALVES ARE CLOSED, MOTOR CIRCUIT BREAKERS LOCKED IN OPEN POISTION, AND THE MEANS FOR OPERATING THIS EQUIPMENT SUITABLY TAGGED) BEFORE ENTERING THE PULVERISER.


a)

Bowl Mill XRP1103

Heating:

Heat must be applied uniformly to the entire piece. Acetylene torches with rosebud tips are not recommended, since heating by this method is not sufficiently uniform. Heat can best be applied in a commercial type oven. However, it is also possible to shroud the part in an insulated enclosure and increase the part temperature with space heaters.

b)

Cooling: Chilling of components can be done in a commercial freezer. It is usually easier to submerge the part, after providing a protective oil or grease coating, in an ice/salt bath or to pack the part in dry ice.

Bowl Mill

11.0. PREVENTIVE MAINTENANCE

11.0

XRP1103

PREVENTIVE MAINTENANCE

Preventive maintenance is conducted to extend the life of the equipment. It involves the regular inspection, testing and replacement OR repair of equipment and operational systems. Preventive maintenance takes proactive approach to the problems before they occur And also saves money from mill breakdowns. . 11.1

MILL CLEARANCES i)

INVERTED CONE CLEARANCE

The inverted cone prevents the Pulverised coal from by-passing the classifier. Inverted cone clearance is the perpendicular distance between the inverted cone and the classifier inner cone.

Bowl Mill


XRP1103

classifier inner cone can occur, which would result in carry over large coal particles to the boiler furnace leading to other related problems periodically. If the clearance is too large, the primary air can carry large particles out of the mill by passing the classifier. This results in poor Pulverised fuel finen ess. ii)

GRINDING ROLL-TO-BULL RING SEGMENT CLEARANCE: The roll-to-ring clearance should be set to 4 to 6 mm parallel for the entire length of the roll in new condition. This clearance setting affects the performance of the mill upon wear.

Bowl Mill


Fig -11.c

iv)

AIR PORT RING CLEARANCES

XRP1103

Bowl Mill


XRP1103

Bowl Mill


XRP1103

The entire journal assembly (Figure - P) including the roll, pivots about the center of the Trunnion shaft and can be raised or lowered with the journal stop bolt. As roll and ring wear progress, the first adjustment is to lower the rolls using the stop bolts. Continue to make stop bolt adjustments until they are no longer effective. Trunnion shaft bushings in the Trunnion shaft end caps support the Trunnion shaft so that when the end caps are rotated from position 1 to 5, the location of the center of the Trunnion shaft is changed and this alters the position of the entire journal assembly. The Trunnion shaft end caps can be used to make roll-ring clearance adjustments, once the stop bolt adjustments are no longer effective in position 1.

a) To make a roll - ring clearance adjustment with the stop bolt:

I) Slack off the journal stop bolt lock nut. Pulveriser running with empty bowl and no coal being fed, slowly retract the journal stop bolt until contact between ring and roll can just be heard or felt with the roll rotating on the journal shaft assembly. Then turn the stop bolt by one flat with new roll and

Bowl Mill


XRP1103

b) To make a roll-ring clearance adjustment using the Trunnion end caps:

Note:

.

When a new grinding elements (rolls and bull ring segments) are fitted in the mill, the trunnion shaft end cap should be positioned one position prior to numeral “1”, by rotating in the opposite direction to the arrow marking made on the end cap face. Once the mill has operated for 1000 hours and wear in the grinding elements sets in there by increasing the gap between the rolls, the Trunnion shaft end cap is to be brought back to its original envisaged position, i.e numeral “1” lines up with indicating arrow on the journal opening cover (JOC). This is done to avoid mill vibrations and other related damages in case the rolls are touching each other during mill operation. i) Slack clamp plate stud locknuts and retract studs several turns. This frees the pressure spring assembly inside the spring cup. Loosen the journal stop bolt lock nut and back out the journal stop bolt until the roll just touches the rings. ii)

Remove the bolts from both Trunnion end caps and slack off the four

Bowl Mill


XRP1103

Bowl Mill


XRP1103

11.2 JOURNAL SPRING COMPRESSION

The spring compression must be set before the pulveriser is placed in service. The initial compression setting (9 or 10 tons) should be checked and if necessary, the springs should be compressed using the spring compression fixture supplied. If some coal or load characteristic causes poor operation changing the spring compression should be considered.

To prevent undue stress on pulveriser components, spring compression on the three journals in one pulveriser should check within 450 Kg.

The most common reasons (and action) for changing spring compression are:

1.

Rough operation at low loads (reduce the compression).

2.

High or unstable power consumption (increase the compression).

Bowl Mill


XRP1103

of 76 mm is required. Screw the nut (item 5) on to the preload stud (item 4) with the cylinder (item 1) fully retracted.

v)

Slide, back off the spring stud locknut keeper from the spring preload stud.

vi)

Use the cylinder to draw the spring guide. To contact the spring housing cover pump the cylinder (item 1) until the pressure gauge reads “P” ± 10 kg/Sq. cm. This will compress the spring “X” from the static length. Using the locknut wrench (item 7) advance the locknut until it contacts the spring guide.

vii)

Before carrying out the journal spring compression initial setting (F Kg’s), ensure that the required information/ data is available to calculate and arrive at the hydraulic cylinder oil pressure (P Kg/ Sq.Cm) to be maintained in the pressure gauge, to achieve the desired result. For this one should have a complete set of hydraulic kit in good working condition, the pressure gauge calibration checked and the hydraulic

Bowl Mill


x)

XRP1103

Remove the preload stud (item 4) and preload fixture (item 2), and install Hex. Hd. cap screw & keeper washer. Torque the Hex. Hd. cap screw to 75 ft-lbs and weld Hex. Hd. cap screw, keeper washer & locknut keeper together.

xi)

Weld a locking plate (L-plate) between the stud lock nut keeper and screw of the journal spring assembly, after performing the journal spring compression setting. This would ensure that the spring stud lock nut would not get disturbed from its place; otherwise it would change the spring compression setting value during mill operation.

xi)

Mount six Hex. nuts onto the adjusting threaded studs. Refer to the ring to roll setting procedure before adjusting these studs.

xii)

The spring compression should be checked whenever time permits to ensure near equal loading all the three springs.

xiii)

The spring compression can be adjusted, by stopping the mill, to get the desired pulverized coal fineness or mill output, especially when the grinding elements are worn out.

Bowl Mill


XRP1103

Bowl Mill


XRP1103

CAUTION USING THE SPRING COMPRESSION MEASUREMENT TAKEN, DO NOT ALLOW THE PRESSURE GAUGE READING TO EXCEED 3000 KG FOR EACH CENTIMETER OF THREAD ENGAGEMENT. THEN BACK OFF THE SPRING ADJUSTING NUT THE DESIRED AMOUNT OR 6 MM. FOR THE PURPOSE OF ESTIMATION, THE FOLLOWING TABLE GIVES THE SPRING RATE FOR THE MI LL.

Mill Size

XRP 1103 1103

Spring Rate ( Kg/Cm) 5359

Spring load to be registered at Pr. gauge in Kg.

9500

Bowl Mill

11.0. PREVENTIVE MAINTENANCE 11.3

XRP1103

CHECKING SPRING COMPRESSION (Refer Figure. 11.f):

It is normally necessary to open the pulveriser in order to check spring compression, but it should be run for 5 minutes with no feed to clear itself of coal. Note: Carryout steps i) to vi) as per Spring preload setting procedure (Refer to 11.2.a). Check the existing setting by applying the hydraulic force up to 70 Kg/Sq.Cm pressure and then fix the dial indicator as well as set it to “0” on the dial, and increase the hydraulic force further, noticing the pressure gauge reading, till the indicator has moved to about 0.2 mm on the dial. At this point, the pressure gauge reading will give the existing spring load set value. If the set value is to be reduced loosen the locknut. If more than 6mm compression is to be moved, release all the hydraulic force, back off the lock nut keeper another 6mm and repeat the above as many times as required.

NOTE:

Bowl Mill

11.0. PREVENTIVE MAINTENANCE 11.4

XRP1103

INSPECTION TASKS

Reliable operation of the mill will be ensured only if inspections and overhauls are carried out at regular intervals so that any faults can be detected and corrected before they result in costly failures. The Bowl mill needs a periodic check to be done on the lubricating system, mill clearances and other operating parameters of mill. The spare parts stored for repairs and overhauls should be checked at regular intervals.

SUGGESTED CHECKLIST FOR MILL PREVENTIVE MAINTENANCE INSPECTION

INSPECTION TASKS 1. Check grinding roll wear depth using the wear measuring gauge and Record the data. Readings may be taken approximately after every 1000 Hrs. of mill operation. 2. Check roll to bowl clearance, nominal clearance for roll to bowl is 4 to 6 mm. If clearance value is not proper, correct it either by adjusting stop bolt or by adjusting Trunnion end caps.

Bowl Mill


XRP1103

It is suggested that, the maintenance staff, based on their experience with the mill in operation, update the inspection tasks check list and follow the same periodically on daily, weekly basis. So that the mill availability and performance can be sustained nearly 100%

12.0. COMPONENT MAINTENANCE

12.0

12.1

Bowl Mill XRP1103

COMPONENT MAINTENANCE

GENERAL DIS-ASSEMBLY AND RE-ASSEMBLY OF COMPONENTS:

ISOLATION OF THE PULVERISER (Refer fig.1):

It is a good operating practice to isolate the pulveriser, before attempting any maintenance job, that calls for opening the mill or dismantling its components. To isolate the mill close the hot gas shut-off gate, the cold gas shut-off gate, the coal line gate (if provided), the feeder discharge valve (if provided) and open the mill feeder motor breakers. (Tag and/or lock open).

For most maintenance procedures a complete general disassembly of the bowl mill is not required. Planetary Gearbox is designed to perform for long time smoothly, provided the operation guide lines are followed strictly. Periodical cleaning of filter element and or replacing the same with spare element, keeping a watch on the oil quality through periodical sampling and testing only are expected to be the normal maintenance


removing the

Bowl Mill XRP1103

fasteners holding the journal opening cover to the journal

opening frame and the Trunnion bushing flange.

3.

Disconnect and remove the lube oil piping, both inlet and outlet side from the gear box, till the withdrawal path is clear. Plug the openings to avoid any dirt entry.

4.

Disconnect the HT / LT and instrument cable connections made to the drive motor and the junction box fitted on the gearbox.

5.

Remove the skirt assembly including the scrapper assembly from the bowl/bowl hub. Remove the labyrinth seal assembly.

6.

Loosen and remove the holding down studs & nuts (M56) between bowl hub and the table top/flange of the gear box. Use hydraulic j acks to loosen the nuts.

7.

Remove the drive coupling guard and disconnect the mill-Motor coupling.


11.

Bowl Mill XRP1103

Alternately, Rig and lift the bowl and bowl hub together using 4 no.’s of 10 tons jacks placed in the mill side air inlet housing to free the bowl hub from the gearbox table top/ flange, by 65 mm. The bowl hub shall clear the keys provided on the table top/ flange of the gear box. Fix suitable size of wooden blocks/ shim plates between the mill side bottom insulation cover plate and the bowl hub. Lower the jacks such that the bowl hub assembly load is transferred to the wooden blocks/ shim plates. Remove the jacks for lifting the gear box as explained below.

12.

Loosen and remove the holding down bolts between gear box and base plate.

13.

Jack and raise the gear box assembly and fix the roller assemblies as shown in Figure G.

14.

Using the pull and lift equipment (2 no’s), one to hold and allow the gear box movement slowly from the rear end, and the other one to pull the gear box out, from the input shaft end, between the concrete piers on to the rails.


Bowl Mill XRP1103

CAUTION FOR DETAILS ON THE ALIGNMENT, LEVELING AND CLEARANCES TO BE MAINTAINED DURING GEARBOX RE-INSTALLATION, WITH THE BASE PLATE, MILL SIDE AIR INLET HOUSING ETC. REFER TO THE SECTION 6 OF THE BOWL MILL ERECTION MANUAL.

1.

Ensure that the gear box assembly is positioned such that the input shaft is facing the Motor side. Lift, move and set the gear box on rollers wh ich are mounted on gear box withdrawal fixture as shown in Figure G.

CAUTION BEFORE MOVING THE GEAR BOX, ENSURE THAT THE THRUST PAD BEARING HOUSING IS FILLED WITH RECOMMENDED LUBRICATING OIL (SERVOMESH SP 320) SO THAT THE THRUST BEARING IS TOTALLY IMMERSED IN THE OIL.

2.

Using the pull and lift equipment, as done previously, slide in the gear box into position.

3. Jack up the gear box and remove the roller assemblies. Lower the gear box on


7.

Bowl Mill XRP1103

Replace all the components removed in the Planetary gear box withdrawal procedure (step 5.0 to 10.0) in the reverse order.

8.

Torque tighten the gear box holding down bolts to the base plate to 391 Kgm.

9.

Rig and place the drive motor in its place, after removing the gear box removal fixture assembly. Fix the holding down bolts (M42) between the Motor and the base plate. Torque tighten them to 259 Kgm.

10. Fix the Mill-Motor coupling, after checking their alignment, as per procedure, and replace the guard assembly. 11. Connect the lube oil piping, HT/LT / instrumentation cables to the respective equipment which were removed for gear box withdrawal (step no. 3 & 4). 12. Establish power supply and run the gear box lube oil system to ensure that there are no leakages and also flush the newly assembled gear box till the filter is found reasonably clear/ clean.


Fig 12.a. JOC WITH PRESSURE SPRING ASSEMBLY

Bowl Mill XRP1103


Bowl Mill XRP1103

12.1.3 DISCHARGE VALVES & MULTIPLE PORT OUTLET ASSEMBLY REMOVAL (Fig. 12.b & Fig.-A) Table shows the removal tasks for multiport outlet assembly REMOVAL TASKS 1.

Disconnect the purge air piping over the mill discharge valves from the air supply header.

2.

Disconnect electricity and compressed air from the mill discharge valve drivers and remove the Victaulic / dresser couplings between the coals feed pipes and the valves.

3.

Disconnect Instrument connection

4.

Unbolt the multi-port outlet assembly flange and remove the assembly with the mill discharge valves from separator top.

5 Unbolt and remove the upper center feed pipe.

5. Unbolt Venturi Assembly and lower it down


Bowl Mill XRP1103

12.1.4 SEPERATOR BODY REMOVAL (Fig. 12.C & Fig-A): Table shows the removal tasks for separator body.

REMOVAL TASKS 1. Remove the bolts from the flange between the separator body and mill side, separator body and separator top. 2.

Disconnect instrument and other piping, and any other equipment attached to the separator body and top. Make adequate slinging facility ready.

3. Remove the entire separator top with deflector assembly, inner cone, feed pipe and liners from mill separator body and place on suitable place. 4. Remove the separator body with liners from mill side liner assembly and place on wooden blocks.


12.1.5

Bowl Mill XRP1103

BOWL AND BOWL HUB REMOVAL After disassembly of the three journal assemblies, the discharge valve and multiple port outlet assembly, and the separator body, follow the procedure given for removal of bowl and bowl hub assembly. Table below shows the removal procedure for bowl and bowl hub. TASKS 1.

Remove the skirt assembly including the scrapper assembly from the bowl/bowl hub.

2.

Remove the labyrinth seal assembly.

3.

Remove the bowl and bowl hub insulation cover sheet and t he insulation.

4. Loosen and remove the holding down studs & nuts (M 52) betw een bowl hub and the table top/flange of the gear box. Use hydraulic jacks to loosen the nuts.


Bowl Mill XRP1103


12.2

Bowl Mill XRP1103

GENERAL DIS-ASSEMBLY AND RE-ASSEMBLY OF OTHER COMPONENTS: The following mill components subjected to wear like bull ring segment and journal rolls are required to renew or replaced periodical intervals based on the inspection reports and date records. The procedure for renewal of bull ring segment, airport ring assembly and journal roll are given below:-

12.2.1 RENEWAL OF BULL RING SEGMENTS (Figure 12.d & FIG-H):

1.

For access to the bowl, remove a journal assembly as per disassembly procedure “Journal Cover and Journal assembly Removal”

2.

Unbolt and remove the split clamping ring. Use the jack screws provided to loosen the ring if necessary. Remove the retaining ring.

3.

Remove the old bull ring segments. It may be necessary to air-arc the first segment into several pieces. When air-arcing, make sure the welding machine is firmly grounded to the bowl. Exercise care not to cut the bowl.


Bowl Mill XRP1103

b)

Check all mill side wall liners are in proper position.

c)

Align and weld new extension ring with bowl.

d)

Use two bolts of bowl and bowl extension ring to hold each segment of rotating vanes in position (of airport assembly). Fix a pointer and by rotating the bowl, level all the vanes in one plane. Tighten the bolts.

e)

Select the highest segment of vane assembly and put a distance piece of thickness 8mm on the outer ring to fix the position of body liner segments. Tackweld the same to the separator body shell.

f)

Repeat the procedure for the rest of the segments of body liners, to complete the circle, taking the reference of the same segment of rotating vane assembly.

g)

Once again check the clearance between vane assembly and body liners by rotating the bowl. It should be within the limit of 8 3mm.

h)

Lock the position of vane assembly and body liners with lock plate temporarily, to avoid distortion during full welding.

i)

Weld all tack weld joints in sequence i.e. diagonally opposite positions and in small pass. Welding rod to be used is E7018 with pre-heating. Also peening of


3.

Bowl Mill XRP1103

After removing journal screws lift the journal head to a vertical position and let it rest on the bottom face of the lower journal housing.

4.

Attach a sling around the journal head and apply just enough strain to take the weight off the bottom face of the lower journal housing. The rigging should be such that the bottom face remains horizontal.

5.

Tap the roll with a brass or lead hammer to knock it off. Do not use a steel hammer, as it may chip the roll and cause injuries. If the roll cannot be tapped off, heat it evenly with a torch or roll removal fixture. TECHNICAL POINT IF THE ROLL IS HEATED, ALLOW THE LOWER JOURNAL HOUSING TO COOL BEFORE LOWERING IT INTO A NEW ROLL.

6.

When the roll is loose, raise the journal out of the roll and lower it into the new roll, placed on 100 X 100 mm blocks to permit the lower journal housing to pass


3.

Bowl Mill XRP1103

Apply RTV sealer to all liner joints. Place liners through on the journal opening frame with an approximate 3 mm gap between the liners. Secure the journal frame liners with weld plugs.

4. 12.2.5

Apply silicone cement to ceramic plugs and install as shown on the weld plug.

JOURNAL HEAD LINER ASSEMBLY REPLACEMENT: Table below shows the replacement tasks of journal head liner assembly

TASKS 1.

Remove worn journal head liners from journal head liners support.

2.

If necessary, wash the tack welds off and remove hex. head screws and journal head liner assembly.

3.

If removed, position journal head liner assembly and secure with hex. head


1)

Bowl Mill XRP1103

Establish the upper bearing bench end play by grinding the spacer supplied with the double bearing.

2)

Assemble the upper journal housing subassembly and check the bearing end play.

3)

Assemble the lower journal housing sub-assembly and install the journal roll.

4)

Assemble the journal shaft sub-assembly.

5)

Assemble journal shaft sub-assembly and journal housing assemblies. Check the journal assembly bearing end play.

6)

Journal Assembly Bearing End-Play

TECHNICAL POINT THE MEASUREMENTS TAKEN DURING THE ASSEMBLY OF THE BEARINGS MUST BE SO


Bowl Mill XRP1103

1 .Establish Upper Bearing Bench End Play TASKS 1.1. Measure and record the upper journal housing bearing bore. Use procedure given in Figure 12.A. Retain data for future reference.

1.2. Grind the bearing spacer. 1.3 Measure and record the spacer length and bearing O.D.; use procedure given in Figure. 12.B. SPACER GRINDING CALCULATION Lateral clearance = (etched on O.D. of Spacer) Lateral clearance = _________________________ Fit = Average bearing O.D. (Fig. 12.B.) - Average housing bore (Fig. 12.A). Fit = (

) - (

) =

Bowl Mill


XRP1103

1. Use dial bore to determine bore dimensions. 2. Measure at two depths, 1/4A and 3/4A, on 45 increments, ‘A’ equals the bearing length or bore depth whichever is smallest. 3 Record readings, BU and BL in the table below. All measurements must agree within 0.0254 mm TIR. 4.

Average the upper, lower and total bore dimension Cu, CL. The average reading D must meet blue print specification that is base dimension + 0.051/0.000 mm.

ORIENTATION

BU UPPER DIMNS.

BL LOWER. DIMNS.

AVERAGE


Bowl Mill XRP1103

Figure – 12.B Journal Bearing Spacer Length Determination

1.

Use a micrometer to measure spacer length “E” at eight locations on 45  intervals


Bowl Mill XRP1103

TASKS 2.1.

Install the double bearing in the upper journal housing along with spacer.

2.1.1 Heat the upper journal housing to 80  C to 100  C. For, ease of assembly, each 0.025 mm of interference requires a 5.5C temperature differential between the bearing cups and bearing housing. NOTE: - To facilitate future disassembly coat the O.D of the bearing cups with Molykote 41 or equal. (If bearings are chilled for insertion coat the bearing housing bore). 2.2 Install the lower bearing cup squarely in the housing, follow in rapid order and sequence

with the finish ground bearing spacer, the bearing cone

assembly(s)., the second bearing cup, the bearing ring (if so equipped) and the bearing keeper. 2.3

Insert and torque the bearing keeper bolts to 6.91 kgm to ensure that the


Bowl Mill XRP1103

3.3 Measure the gap between the end face of the housing and the bearing keeper In four places, reference Figure-12.D. Average the measurements. 3.4 Assemble a shim ack with a total thickness of 0.0762 mm to 0.127 mm less than the gap measured in step 4.3. Check thickness of the shims with a micrometer. 3.5 Remove cap screws and bearing keeper. Assemble the shim pack to the Upper housing. 3.6 Replace the bearing keeper. 3.7 Use a thread locking/sealant, reinstall the cap screws and uniformly torque.

TECHNICAL POINT AS AN ALTERNATE ASSEMBLY METHOD, THE BEARING CUPS AND SPACER MAY BE CHILLED IN DRY ICE INSTEAD OF HEATING THE BEARING HOUSING. IF THE CHILLING METHOD IS USED, THE BEARING CUPS AND CONES AND ROLLER BEARINGS MUST BE COMPLETELY COATED WITH THE RECOMMENDED JOURNAL OIL IMMEDIATELY AFTER ASSEMBLY TO PPREVENT “WATER ETCHING”.


1.

Bowl Mill XRP1103

Use a micrometer to measure the outside diameter of the bearing cups at four locations 0, 45 , 90, and 135.


1.

Bowl Mill XRP1103

Measure clearance between the bearing housing and bearing keeper with a feeler gauge at four locations.


Bowl Mill XRP1103

TASKS 4.0 Check upper bearing end play 4.1 Arrange the upper journal housing and bearings in the end play fixture. Refer to Figure 12.F. A base capable of withstanding a lift load of 2000 kg must be made available.

4.2 Attach an overhead hoist, a come-along and a direct reading load cell of approximately 5 ton capacity to the eyebolt of the end play fixture. All components must be of sufficient capacity to withstand the lift load of bearing, upper housing assembly given on the Upper Bearing Lift Load and End Play Table -12.

4.3 Mount three dial indicators as shown in Figure.12. F. Rest the contact buttons on the top of the housing.


Bowl Mill XRP1103

4.11 Repeat steps 4.5 through 4.10 until at least three average readings are recorded on worksheet. 4.12 Average the average readings on the worksheet and record. The final value must be within the end play limits give on the Upper Bearing End Play Table (Table 12) or the assembly must be reworked.


Bowl Mill XRP1103

Bowl Mill


Trial

Indicator A

1

2

3

4

5

Indicator Readings No Load Lifted No Load HA

B

HB

C

HC

A

HA

B

HB

C

HC

A

HA

B

HB

C

HC

A

HA

B

HB

C

HC

A

HA

B

HB

XRP1103

AVG. Readings Lifted Position H1 AVG. = HA+HB+HC 3

H2 AVG =

H3AVG =

H4AVG =

H5AVG =

Bowl Mill


XRP1103

USAGE

When using this table ensure that the upper bearing and upper housing part number match those listed in the table.

The lift load is used in determining upper bearing end play described in steps 4.1 through 4.12. The results obtained in step 4.12 should be compared with the values for the end play tolerance given in Table 12.

The values given are used in determining journal housing flange gap shims, Step: 13.5 and Figure 12.L. and journal assembly end play steps 13.6 through 13.14 and Fig 12.M.

UPPER BEARING Mill Size

JOURNAL ASSEMBLY

Load

End play

Load

End play ‘A’

(Kgs)

(mm)

(Kgs.)

(mm)


Bowl Mill XRP1103

2. Assemble the Lower Journal Housing Sub-Assembly

TASKS 5.

Grinding Roll with taper fit connection.

5.1 Use Prussian blue to determine the contact pattern between the lower housing taper and the grinding roll taper. There must be at least 80% contact between the mating tapers and any “no contact” zones must not exceed 10  of arc. Modify the roll to achieve proper contact.

5.2 Once the taper contact has been verified, press the grinding roll and lower housing together with 50 tons force. 5.3 Tighten the locknut on the lower housing while maintaining the 50 ton force. 5.4 Spot drill the grinding roll through the set screw holes.


Bowl Mill XRP1103

6.2

Measure the O.D. of the lower journal bearing cup, reference procedures on Figure C. Record on Figure-J.

6.3

Calculate the bearing housing interference F3 AVG minus DB. It must be between 0.025 mm and 0.180 mm.

6.4

Coat the lower journal housing bearing bore with Molykote 41 or equal.

6.5

Chill the lower bearing cup in dry ice or liquid nitrogen and install in lower housing.

NOTE: - AS THE BEARING CUP RETURNS TO NORMAL TEMPERATURE WIPE DRY AND COAT WITH JOURNAL OIL TO PREVENT WATER ETCHING. 6.6 After the cup has returned to room temperature, check beneath the cup with a feeler gauge to assure proper seating. A 0.025 mm feeler gauge must not fit between the bearing cup and the housing backing shoulder.

Bowl Mill


XRP1103

Note: For Bore determination use procedure Figure 12.A: For Bearing O.D. use procedure Figure 12.C. ORIENTATION

BRG. BORE BBL

0

BBU

PILOT BORE BPL

BPU

LWR. BRG. CUP F3 OUTSIDE DIM


Bowl Mill XRP1103

4. Journal Shaft Sub-Assembly TASKS 7. Check the journal shaft for straightness and roundness. Measure and record the information, reference Figure12. K. The shaft must be straight and round with in 0.025 mm. 8.0 Assembly of long spacer shaft journals 8.1

Install the oil seal wear ring.

8.2

Measure the I.D. of the oil seal wear ring, compare with shaft O.D. measurements. The interference must be between 0.102 to 0.28 mm.

8.3

Heat oil seal wear ring in an oven or in oil to 150C maximum.

8.4

Locate oil seal wear ring on journal shaft as shown in the assembly drawing (either by a given dimension or against a shaft shoulder). Allow wear ring to cool.

9.

Install the upper bearing assembly


10.

Bowl Mill XRP1103

Install the lower journal bearing cone

10.1 Assemble the lower bearing spacer (if applicable) on the journal shaft. The chamfer on the spacer must clear the shaft fillet. 10.2 Coat the lower bearing seat on the journal shaft with Molykote 41 or equal. 10.3 Check the I.D. of the bearing cone, use procedure Figure 12.A and compare with shaft measurement Figure12. K. The interference must be between 0.025 to 0.178 mm. 10.4 Heat the bearing cone in an oven or oil bath to 120C maximum and install it on the journal shaft. 10.5 Install the bearing keeper and torque cap screws to 14 kgm. 10.6 Allow bearing to return to room temperature. 10.7

Check with a feeler gauge to assure proper seating of the bearing. A 0.025 mm feeler gauge must not fit between the bearing spacer and cone or the


Bowl Mill XRP1103

5. Assemble the Journal Shaft to the Housing Assemblies TASKS 12

Assemble journal shaft with housing and sub-assemblies.

NOTE:- PRIOR TO ASSEMBLY COAT ALL BEARINGS WITH STANDARD JOURNAL OIL 12.1 Install a lifting eye in the end of the journal shaft. 12.2

On journal shafts with the long spacer, lower the shaft and upper housing assembly without the “O” ring & the spring pins into the lower housing and seat the lower bearing cone in its cup.

12.3 Turn the shaft five complete revolutions in one direction. 12.4 Measure the gap between the upper and lower journal housing flanges in eight places, 45 increments, with feeler gauges. Record the reading, reference Figure. 12. L. all readings should be alike within 0.076 mm. Average the readings. 12.5

Prepare a shim pack with a thickness equal to the average housing gap


6

Bowl Mill XRP1103

Journal Assembly Bearing End-Play TASKS 13

Check journal assembly bearing end play.

13.1 Fasten two rods threaded at their lower ends in the lifting holes in the flange of the upper journal housing 13.2 Lock the rods with hex nuts.

13.3 Install a dial indicator on each rod. Mark the indicator locations (1800 apart) on the top of the journal shaft.

13.4 Rotate the journal five revolutions in one direction and return the dial indicators to their marked locations.

13.5 Zero the indicators.


Bowl Mill XRP1103

13.12 Zero the dial indicators and repeat steps 13.6 through 13.11 until three average indicator readings, within 0.025 mm are obtained.

13.13 Average the three average readings.

13.14 The value obtained in step 13.13 should be 1/2 the end play of the two row bearing, Figure 12.F. plus value “A” from the Assembly End Play Ta ble (Table 12). The acceptable tolerance is 0.025 mm. 13.15 If the journal assembly end play is not within acceptable limits, disassemble the housings, and adjust shims (steps 12.3 through 12.9) as required. After shims are adjusted, recheck journal assembly end play by repeating steps 13.1 through 13.14. 13.16 If the journal assembly end play is within the acceptable limits, remove the rods installed in step 13.1 and plug the lifting and jack screw holes in the upper journal bearing with set screws.

Bowl Mill


XRP1103

Shaft Outside Diameter Measurements. Use a Micrometer. ORIENTATION

L.R. BRG. SEAT K

0 45 90 135

UPP. BRG. SEAT L

M

SEAL RING SEG N

Bowl Mill


A

XRP1103

UPPER JOURNAL HOUSING FLANGE GAP Orientation

1st TRIAL GAP

2nd TRIAL GAP

3 rd TRIAL GAP

0 45 90 135 180 225 270 315 AVG. Shim Pack = AVG Gap +

SHIM PACK = (

Bearing end play,Step 4.12

)+(

2. )+(

+ End play ' A' Table - 12

)

Bowl Mill


TRIAL

INDICATOR

INDICATOR READINGS No Load

1

A

2

3

4

5

HAVG =

2

Lifted

AVG. READINGS No. Load

HA

B

HB

A

HA

B

HB

A

HA

B

HB

A

HA

B

HB

A

HA

B 1

XRP1103

H1 AVG =

H2 AVG =

H3 AVG =

H4 AVG =

H5 AVG =

HB 3

4

5

H AVG + H AVG+ H AVG + H AVG + H AVG 5

LIFTED POSITION

=

H A + HB 2


Bowl Mill XRP1103

12.4 JOURNAL HEAD TO JOURNAL SHAFT ASSEMBLY a.

Lubricate the threads on the journal shaft with anti-seize compound and install the lock nut.

b.

Slug lock-nut tight using the supplied wrench and a sledge hammer. Scribe the nut and the head with chalk and strike the wrench with three additional solid blows of the sledge hammer. If the nut moves less than 3 mm, it is sufficiently tight. If the nut moves more than 3 mm the tightening process should be repeated. Lock the set-screw on the lock nut once it is properly tightened.

c. Weld a locking plate (L-Plate) between the lock nut and journal shaft,. This would ensure that the stud lock would get disturbed from its place. d.

Stamp the serial number of the journal assembly which is located on the end of the journal shaft on the journal head for future identification.

Bowl Mill


XRP1103

12.5 Adjustment of the Seal Air Gap

ORIENTATION

0 45 90 135 180 225 270 315 AVG GAP =

0 + 45+...........315 8

1st TRIAL

2nd TRIAL

3 rd TRIAL

GAP

GAP

GAP


Bowl Mill XRP1103

Caps through the Separator Body Journal Opening. Install the Roller Journal Assembly by carefully lowering it through the Journal Opening i n the Separator Body. Bolt up the Trunnion shaft End caps on to the Journal opening frame on either side. This will partially support the Trunnion shaft ends, Bring in the match marked journal opening cover and assemble on to the separator body. The Trunnion end caps should be turned so that the numeral "-1" lines up with the indicating arrow on the Journal opening cover.

Tighten all bolts connecting separator body and Journal Opening Cover. DO NOT INTERCHANGE THE JOURNAL OPENING COVERS AS THESE HAVE BEEN MATCH MACHINED WITH THE SEPARATOR BODY. Draw up tight the other bolts connecting the Trunnion Shaft End Caps and the Journal Opening Cover. Proceed with the remaining setting up of ring roll clearance and spring compression as described elsewhere in this manual.

13.0. STORAGE AND PRESERVATION OF MILL COMPONENTS

Bowl Mill XRP1103

13.0 STORAGE AND PRESERVATION OF MILL COMPONENTS When the mill is not operated for more than one week, any one of the following preservation procedures may be adopted to protect th e interior parts of the gear case like worm shaft, vertical shaft, bearings, worm gear etc.

13.1 PRESERVATION WITH PRESERVATIVE Before longer storage times, the gear unit should be run with no load with preservative.

We recommend the preservatives listed in the table below for preservation of the gear unit:

STORAGE SATBILITY up to 24 months

PRESERVATIVE

SPECIAL MEASURES

SERVOMESH SP320 OF

Plug the gear unit air tight, replace air filter with plug screws (replace before startup)

IOC


Bowl Mill XRP1103

OIL TESTING: The

CAUTION THERE IS A RISK OF SCALDING FROM HOT PRESERVATIVE EMERGING. WEAR PROTECTIVE GLOVES.

oil may be

tested every 3 months to ensure its properties. Refer PGB section for oil properties and impurity limits.

13.2

SPARE ROLLER JOURNAL ASSEMBLIES PRESERVATION: These assemblies shall be stored in closed storage in vertical position (Standing on roll).The journal assemblies are completely filled with recommended lube oil prior to shipments from workshops. Oil to be used: Servo Mesh

SP 680 of IOC. At site, the

condition of oil, level and leakage if any should be checked periodically. Use Oil Dip Stick for level measurement. Prior to commissioning excess oil is to be removed with the help of siphon hand pump.


Bowl Mill XRP1103

etc. These assemblies should be stored in fully covered condition with the integrally mounted instrumentation components protected against moisture and dust.

13.6

INTERIOR AREAS: The air passages, grinding and classifying areas of the Mill, Mill Discharge Valve, Reject Hoppers, etc. should be stored under cover and protected as much as possible. Water should not be allowed to accumulate and stand in or on these parts.

13.7

MILL MOTOR: Follow manufacturer’s instructions.

13.8

GENERAL: All exposed machined surfaces like shaft extensions, threaded or drilled bolt holes, classifier link mechanisms should be periodically preserved with protective grease or by such means and covered. Note: Refer Lubrication Schedule (TABLE-1), for the recommended Lubricants.

13.0. STORAGE AND PRESERVATION OF MILL COMPONENTS vi.

Bowl Mill XRP1103

The breather assembly fitted to the Gearbox (two numbers) shall be removed and the opening to be sealed with a screw plug. The breather assembly from the thrust pad bearing chamber shall be removed only after completion of oil filling activity and then plugged.

a. i.

Filling with oil The oil to be put in must be filtered beforehand with a 25 micron filter gauge. Note: Re-use and preparation of the recommended lube oil, for normal operation, after long periods of preservation and storage must be checked up with the oil manufacturer.

ii.

The gear unit must be filled with oil via the oil drain valve of the thrust pad chamber. During filling care must be taken that the vent of the “Preservation cap” fitted at site on the input shaft is not sealed until oil emerges from it. Oil filling further shall be continued after sealing the cap vent, once oil emerges from it.

iii. The rate of filling the oil into the thrust pad bearing chamber shall be such that oil


Bowl Mill XRP1103

viii. Before starting up the gear unit the preservation oil must be drained off at the oil drain points on the thrust pad bearing chamber and the gear unit base. The Preservation cap is to be dismantled and stored for future use. The breather assemblies have to be installed back in their position and the thrust bearing housing labyrinth seal adhesive tape shall be removed. Then installation and start-up of the spare Gearbox must be carried out in accordance with the Erection/ O&M instruction manuals. ix. The quantity of Lube oil required per mill for filling Gearbox top and bottom chambers together is 1000Liters. Long term preservation of Gearbox fitted in mill and put into operation: For Gearbox which is in operation, in case the unit outage is for long period, the long term preservation procedure is different. In that case we need to run the Lube oil system for one hour and then the mill at no load for 15 minutes to ensure that all the gearbox internals are thoroughly lubricated and oil film applied. Otherwise, with lube oil system kept in service, the Gearbox input shaft shall be manually rotated such


Bowl Mill XRP1103

Long Time Preservation Method - Preparation – Fixing of end cap on the input shaft to avoid oil leakage when the housing is filled with lube oil up to the output flange labyrinth seal


Bowl Mill XRP1103

14.0. SPARES

Bowl Mill XRP1103

14.0 SPARES A stock of spares for important replacement and wearing parts is essential for satisfactory operation and serviceability of the bowl mill at all times. Classification of Bowl Mill spares are given below:-

BOWL MILL SPARES - CLASSIFICATION Bowl mill spares can be classified on the given following basis. i.

Long Delivery Items

ii.

Short Delivery Items

iii.

Low Value Items

iv.

High Value Items

v.

Fast Wear Items

vi.

Special Items

LONG DELIVERY ITEMS (DELIVERY 12 TO 18 MONTHS) This type of items consist following spares

14.0. SPARES

Bowl Mill XRP1103

SHORT DELIVERY ITEMS This type of items consists following spares. i.

Trunnion Shaft end Cap

ii.

Bowl Extension ring

iii.

Air Seal & Dust Guard Assembly

iv.

Seal assembly And Seal Runner Assembly

v.

Scraper Assembly

vi.

Valve Body & MPO

vii.

Inner cone

FAST WEAR OUT ITEMS (DELIVERY 6 TO 12 MONTHS) This type of items consists following spares:-

i.

Grinding Elements Like Rolls & Bull Rings

ii.

All Liners Like 

Journal Head Liners

14.0. SPARES

Bowl Mill XRP1103

14.1

RECOMMENDED SPARES LIST

ONE MILL QTY FORMS A SET – REFER O&M MANUAL FOR FIGURE REFERRED HEREIN: SL

DESCRIPTION OF PART

NO

NO. OFF PER MILL

RECOMMEND ED SETS./ 8 MILLS

UNIT OF MEASUR EMENT

FIGUREN O- ITEM NO

A

ROLLER JOURNAL ASSEMBLY- FIG

01

3

24

SET

P-08

3

3

SET

FIG R

03

GRINDING ROLLS – 62 " (SINTERED CARBIDE INSERT TYPE) JOURNAL ASSEMBLY (WITH G.ROLLS & LINERS) JOURNAL BEARING LOWER

3

8

SET

P-02

04

JOURNAL BEARING (UPPER)

3

8

SET

P-01

3

8

SET

P-14

3

8

NO’s

Q-02

3

42

SET

R-04

3

8

SET

P-09

3

24

SET

P-10

02

05 06 07 08 09

JOURNAL CAP SCREW LOCK PLATE JOURNAL HEAD JOURNAL HEAD LINERS SET TYPES) JOURNAL SHAFT

(5-

HEX. Head SCREW M 36 x110

14.0. SPARES

Bowl Mill XRP1103

26

SHIM SET ( UPP BRG KEEPER)

3

8

SET

P-18

27

SEAL WEAR RING

3

5

SET

P-21

28

AIR SEAT RING UPPER

3

2

SET

Q-16

29

AIR SEAL RING SHIM SET

3

2

SET

Q-17

B

MILL DRIVE & BOWL ASSY.

01

BOWL EXN.RING SEGMENT

1 SET

42

SET

V-18

02

BOWL HUB CLAMPING RING

1 SET

24

SET

V-13

03

BOWL HUB COVER

1

8

SET

V-08

05

1 SET

24

SET

V- 17

06

BULL RING SEGMENT ASSEMBLYHICHROME LAYBRINGTH SEAL ASSEMBLY

1

8

SET

V-27

07

SKIRT ASSY

1

5

SET

V-20

08

SCRAPER

2

24

SET

S-03

09

SCRAPER & GUARD ASSY

2

8

SET

V-22

10

SCRAPER BUSH

4

33

SET

S-12

14.0. SPARES

Bowl Mill XRP1103

14

JOURNAL STOP BOLT BUSHING

6

24

SET

A-32

15

O-RING OIL SEAL (STOP BOLT)

3

6

SET

A-33

16

OUT LET VENTURY ASSEMBLY

1

8

SET

A-17

17

1

8

SET

A-28

4

8

SET

A-22

19

OUT LET VENTURY COLLAR ASSEMBLY VENTURI VANE (WITH CERAMIC LINER DRUM SECTION

1

8

SET

A-29

20

CENTER FEED PIPE UPPER

1

4

NO

A-20

21

GASKET FOR VICTAULIC COUPLING

4

8

SET

A-34

22

GASKET FOR DRESSER COUPLING

1

8

NO

A-21

E

MILL DISCHARGE VALVE ASSEMBLY

18

01

MDV ASSEMBLY

1

8

NO

01

CERAMIC LINED VALVE BODY

4

8

SET

A-19

02

CERAMIC LINED MPO

4

8

SET

A-30

02

GASKET FOR FLANGE

1

20

SET

A-31

01

SOLENOID VALVES

2

8

SET



            

        

   

      

        





Derang Jitpl-o&m Manual_xrp1103-1 Mill

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