VA1 NHI 00100 M M1C MAN 0003 Rev1 Coal Mill Operation Manual

DOCUMENT DOCUMENT SUBMISSION SUBMISSION STATUS: STATUS: FC

1

20132013-0303-25 25

0

2012-12-01 2012-12-01

REV

DATE

4 paragraphs be modified which painted yellow DESCRIPTION

OWNER

Zhang Pengxiao Pengxiao

Li Hongsheng

Yu Tingwei

Zhang Pengxiao

Li Hongs heng

Yu Tingw ei

DRWN

CHKD

APPN

OWNER’S CONSULTANT

POYRY ENERGY LTD

VIETNAM OIL AND GAS GROUP (PVN) EPC CONTRACTOR

EPC CONTRACTOR’S CONSULTANT

VIETNAM MACHINERY MA CHINERY INSTALLATIONCORPPORATION (LILAMA)

FICHTNER GmbH & Co. KG

PROJECT TITLE

VUNG ANG 1 THERMAL THERMAL POWER PLANT 2 x 600MW CONTRACT No.

251209/LILAMA-NHI

DRAWING TITLE

Coal Mill Operation Manual SUB-CONTRACTOR

NORTHERN HEAVY INDUSTRIES GROUP CO.LTD

FUNC FUNCTI TION ON

NAM NAME

DRWN DRWN

Zhan Zhang g Peng Pengxi xiao ao

13-0 13-033-25 25

CHKD

Li Hongsheng

13-03-25

Yu Tingwei

13-03-25

APPD

SIGN IGN

SCALE

DOCUMENT No.

VA1-NHI-00100-M-M1C-MAN VA1-NHI-00100-M-M1C-MAN 0003

DATE DATE

REV

1

Vung Ang I Thermal Power Plant 2×600MW Coal Fired Project

Coal Mill Operation Manual

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Content 1. General 1.1 Principle of operation 1.2 Mechanical instruction 1.3 Instruction of control system 2. Preparation before Preoperation 2.1 Visual inspection 2.2 Pipeline inspection 2.3 Inspection on electric and instrument 2.4 Mechanical inspection 2.5 Charging lubrication and grease 2.6 Manual inspection 3. First Operation (preoperation) 3.1 General principle 3.2 Special regulations for several devices 3.3 Inspection after first operation 4. Operation (ball charged) 4.1 First step 4.2 Second step 4.3 Third step and Fourth Step 5. Inspection before Operation 6. Startup of Coal Mill without Coal 6.1 Startup of the first coal mill after the combustion of fuel 6.2 Startup of coal mills without coal except for the first coal mill 7. Startup of Coal Mill with Coal (After Abnormal Stop or Tripping Operation) 7.1 Startup of the first coal mill (without the other coal mills) 7.2 Startup of the other coal mills 8. Shut Down 9. Emptying the Coal Mill 9.1 Partial emptying 9.2 Complete emptying 9.3 Sign when no coal in the coal mill 9.4 Sign when overload 9.5 Ball charge during operation



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Attachments:

1. Check Sheet for non-load operation of main motor (without coupling) 2. Trail Run Check Sheet for main motor (connected to ball mill) 3. Check Sheet for ball charging test operation



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1. General

1.1 Principle of operation Double-inlet and Double-outlet Coal Mill (BBD) comprises two grinding loops which are arranged symmetrically. Each loop can be described as follow: The raw coal is discharged from the chute by a coal feeder, the speed of which can be controlled automatically. The coal is conveyed to the mixer from the outlet of the coal feeder, and then dried by the by-pass air. Then, the coal is conveyed into the coal mill through the hollow shaft by the rotary movement of the screw convey device. Finally, the grinding to the coal is carried out by the steel balls inside the rotating shell. Hot primary air blows into the coal mill through the center pipe of the hollow shaft. After dried the coal, the primary air conveys the pulverized coal out of the coal mill along the reverse direction of the raw coal through an annular channel arranged between the center pipe and the hollow shaft. The pulverized coal, primary air and the by-pass air which comes from the mixer are mixed together, and get into the classifier. In normal condition, the classifier and the coal feeder are installed at the same height. The double-cone classifier is provided with adjustable laminas which can adjust the fineness of the coal according to specified requirements. The unqualified coal would fall back to the inlet of the hollow shaft because of the gravity force, and get back with the raw coal for re-grinding. The qualified pulverized coal is suspended in the primary air, conveyed to the burner from the outlet of the classifier, and then blown into the boiler for combustion. The only grinding medium for the coal mill is steel ball, and the grind is carried out by the friction between the coal and the steel ball. Because of the friction, the grinding medium will suffer unavoidable abrasion. When coal is provided with high-load of corrosive ash or the requirement for pulverized fineness is strict, the abrasion will be highly increased. 1.2 Mechanical instruction The coal mill is mainly formed by a hollow shaft and a rotating shell which is arranged on two bearings (one on each side). 1.2.1 Shell



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The shell comprises a shell which is rolled and welded, and two heads which are welded on the shell. Wear-resistant linings are installed inside the shell and the heads, and the steel balls can be driven by the linings. 1.2.2 Hollow shaft The hollow shaft is a hollow body which is fixed on the heads by bolts. It has two functions: (1) The hollow shaft can be used for air supply, coal feed and mixture discharge of air and pulverized coal The heat air gets into the coal mill through the center pipe which is rotated by beam. The inner side of the beam is fixed on the lining, and the outer side is supported by roller bearings outside a heat-air inlet case. The coal is sent into the shell by helical laminaes which are fixed outside the center pipe through protective chain. (2) The hollow shaft can rotate the shell with the coordination of sliding bearing. 1.2.3 Bearing The structure of the bearing can compensate the sag of the coal mill with loads. The bearing is made of wear-resistant metal, and can avoid damages. The bearing pedestal is formed by welded steel components. During lubrication, the oil is transmitted by a hydraulic drive device: - During high pressure, the oil is transmitted under the hollow shaft to float the hollow shaft. - During low pressure, plenty oil is transmitted onto the hollow shaft for cooling. The oil is transmitted under the hollow shaft for lubrication. 1.2.4 Seal system During operation, the coal mill is in positive pressure. Thus, a special connecting component which is used for preventing the pulverized coal from getting into the outside air is arranged between the fixing components and rotating components of the hollow shaft. The connecting component is a flange made of composite material, which is stuck to the smooth component. The seal air fan provides the opposite pressure to avoid the leakage of pulverized coal. 1.2.5 Classifier



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The dynamic classifier is assembled with variable frequency motor the frequency of which can be changed by the frequency converter. Therefore, the speed of the rotor blades of the classifier can be changed between 0 ～ 150r/min to change the fineness of the pulverized coal. 1.2.6 Drive device The drive device is used for driving the coal mill, and the power is provided by motor. The speed of the motor is reduced by speed reducer. The output end of the speed reducer is used for driving the center shaft of the pinion, and then the pinion meshes the girth gear to drive the shell. Automatic jet lubrication is used on the pinion and girth gear, and spray lubrication is used on speed reducer. 1.2.7 Inch device (low-speed drive) The inch device can drive the coal mill with the 1/100 speed of the rated speed during maintenance and stop. Thus, specified position of the stop of the coal mill can be achieved. 1.2.8 Sound-proof shield A sound-proof shield is installed because of the noise made by the coal mill. The shield is made of structural steel with a layer of mineral wool inside. 1.2.9 Ball charge system The ball charge system can charge balls into the coal mill without stop. Each coal mill is provided with one ball charge system. 1.2.10 Inert system Inert system is used for transmitting steam into the coal mill during stop. 1.2.11 Fire-extinguishing system This system is used for extinguishing fire. When the fire alarm rang out, the system can spray fire fighting steam into the coal mill. 1.3 Instruction of control system 1.3.1 The temperature control of the blast-coal mixture at outlet of the classifier The temperature control can be achieved by adjusting the opening of heat and cool air baffle plates. The temperature of the pulverized coal is controlled by the primary air, which limits the temperature of the outlet in certain range.



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1.3.2 Volume control of primary air The volume control can achieve a proportion between the primary air and the by-pass air. The signal for transmitting the primary air is sent out by main controller: 1) The air volume through the coal mill is adjusted in accordance to the flow rate at outlet of coal mill. 2) The volume of the by-pass air is adjusted in accordance to the flow rate at outlet of coal mill. 1.3.3 Adjustment of coal level inside coal mill 1) The output of pulverized coal is modified in accordance to the load of the boiler, and the coal feed volume is also modified relevantly. 2) No matter how the load of the coal mill is changed, the coal level inside the coal mill shall retain the same. 3) The control of the coal level is achieved by the coal level detection, which can be achieved by two ways: - by controlling the differential pressures at two points The pressures between two different points are detected, and ar e sent to the speed controller of the coal feeder. Then the speed of the coal feeder is adjusted to retain the same pressure at different points. - by the electric ear device The coal level is controlled by detecting the sound signal to adjust the volume of primary air and the speed of the coal feeder. As a main control method of the coal level, the differential pressures measuring device controls the coal feeder. The electric ear device is an auxiliary control device used at the starting stage of operation to output control signal. During the starting stage, the differential pressures is not stable enough to provide rightful information of coal level. The signal from electric ear device can provide a general information inside the shell to the operator as a protection to avoid the situation of coal blockage inside or lack of coal inside. 1.3.4 Automatic control system The coal mill is provided with an automatic control device to guarantee safety when error occurs during operation. When error occurs to the boiler, at which emergency shut down is needed, the coal mill shall be provided with other self-protection device, such as non-stop of lubrication and start of low-speed drive.



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The inlet and outlet of the coal mill are provided with valves which can be used for isolating the coal mill when the entire system stops. 2. Preparation before Preoperation

2.1 Visual inspection Before start the coal mill, the following ordinary inspections shall be carried out: 1) All parts and components shall be assembled well, and all important devices shall not be lost. In this case, the coal mill can be started safely. 2) No obvious damage occurs, and all devices are in good conditions. 3) No error is allowed during installation, or the installation shall be carried out again from the start. The installation of all components shall be carried out strictly in accordance to the instruction. The questions about the installation shall be raised immediately during installation. 4) The sundries (such as tools, scrap iron, scrap wood, etc) are not allowed to retain in coal mill. 2.2 Pipeline inspection Before operation, all pipeline shall be inspected and get ready. 1) Inspection is carried out to all valves (rotation, open, and close). Then the valves are set into the condition of opening or close in accordance to the requirements of working condition. 2) All necessary parts (such as water and comprised air) are prepared, and the performance (such as temperature and pressure) is checked. 3) All pipes are drained, and then the outlet valves are closed. 2.3 Inspection on electric and instrument Ordinary inspections are carried out to the electric and instruments in accordance to the following requirements: 1) Inspections are carried out to all wire connections (including power, control and instruments). 2) All cables are arranged, and are assembled with bushing.



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3) Operation inspection is carried out to instrument (such as flow switch, pressure switch, switch and baffle plate) if possible. 4) All junction boxes and control cabinets shall be open for inspection. 5) Fuse and interlock devices are disconnected for inspection separately. 6) The electric devices are disconnected with the main machines for nonload operation to inspect the current and the rotating direction. 7) The power consumption of the electric devices is recorded when the devices are disconnected with the main machines. 2.4 Mechanical inspection First, the stableness of the foundation bolts for main components and auxiliary devices are inspected. The drive devices must be inspected. The couplings shall be disassembled for the inspection of axiality if necessary. 2.5 Charging lubrication and grease The cleanliness of all lubrication pipes are inspected. The devices need lubrication, and the specification and quantity for the oil are marked in the instruction of lubrication. Then, the charge for lubrication and grease can be carried out. 2.6 Manual inspection Most devices shall be rotated by hand to inspect whether there is interference or inflexibility. 3. First Operation (preoperation)

3.1 General principle In order to execute start operation for single coal mill, the interlock devices shall be disconnected. The first preoperation shall be non-load operation without coal and steel balls. Simultaneously, the coal mill shall be disconnected with the boiler, but safety devices shall be in application.



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The instruments shall be started in accordance to procedures gradually without using the interlock device. Device cannot be started individually unless the instruments have been in operation for a while or all operational parameters are stable. Then, inspections are carried out to the operation and setting position of the instruments. During operation, the technical staff shall inspect the following item near the devices: - Temperature (such as bearings) must not be high. - No abnormal noise exists. - Whether the wastage of the motor is close to the value of calculation. - No leakage (such as water, oil) occurs. - The oil level is correct. - Oil film thickness of the main bearing is inspected, as the coal mill could be jacked up by operating the jacking oil pump of the main bearing. The abnormal occurrence during the first operation should be analyzed and solved, and make sure that there is no problem left. 3.2 Special regulations for several devices 3.2.1Bearing lubrication The commissioning of the lubrication device must be carried out in the manufacturer and the device can’t be used without the oil, the electric heater switch and cooling circuit shall be provided, when the oil temperature meets the requirements, the oil pump is started and the oil condition is inspected, (if there is no oil in one minute, the inspection to oil pump shall be ceased) The inspections are carried out to the oil mist on the hollow shaft (the both side are equal), and the oil return is normal. The oil pressure of the high-pressure pump is inspected, and the raised height of the both side of coal mill is recorded. The oil level in the tank in inspected, the oil level must be over the height of pipeline and be above the minimum oil level. The filter of the low pressure pump should be cleaned regularly. 3.2.2 Lubrication of speed reducer



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The motor is started and the inspections are carried out to the oil condition. The filter must be cleaned frequently. If possible, the access eye shall be opened to inspect the spray condition in the speed reducer. 3.2.3Lubrication of girth gear The pressure of the comprised air is inspected and there is no moisture in the air. The girth gear is started for one circle regularly. The operations of all the components are inspected, especially the injection oil on the girth gear. The nozzle should cover the entire width of the girth gear and the formed oil films are similar. The jet circle and the interval between the two jets are adjusted. 3.2.4 Coal mill Warning: the coal mill must be started without the steel ball and coal. The sealed fan of gear cover, the motor and speed reducer are started. The coal mill is ceased after the 30 minutes smoothly operation. The bearing temperature is monitored during the operation, if the bearing temperature is too high, the coal mill shall be ceased, and the conditions of race rotation and oil film are inspected by the observation door on the bearing cap. The vibrations of the coal mill are inspected. The inspections are carried out to the operations of the girth gear and main bearing. The power equipment of the coal mill drive is observed. 3.2.5 Main electric machine of the coal mill The bearing temperature is inspected. The winding temperature is inspected. The absorbed power of the electric machine is recorded. 3.2.6 Screw convey device The frictions between the stranding cage and hollow shaft are inspected (listening).



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The temperature of the steady bearing is inspected. The inspections are carried out to the vibrations. 3.2.7 Trial run of dynamic classifier The following shall be checked before the trial run: Check the direction of the stator blade. Check the rotating direction of the classifier motor (shall be counterclockwise direction seen from ouotput shaft) Check the condition of the lubricant and grease on the speed reducer and the transmission part of the classifier. Check the connection of the seal air pipe. Check whether there’s leakage. Start up the variable frequency motor. The design speed of the rotor blade on classifier is 107rad/min. The speed can be adjusted based on the actual condition during operation. The trial run of the classifier is 4 hours. Check the stability of the rotor blade rotation. Check the classifier whether there’s abnormal noise or vibration. When the coal mill is put into operation, the blades of the classifier shall be checked regularly in case there’s material winding on the blade. The grease shall be added to the transmission part of the classifier regularly by manual pump. 3.2.8 The operations of all the control system are inspected. 3.2.9 The raw-fuel feeder is inspected in accordance to the manufactory instructions. 3.3 Inspection after first operation The coal mill and auxiliary device are inspected after first operation (30 minutes at most), and the errors shall be recorded and be restored or regulated. 4. Operation (ball charged)

The amount of steel balls is increase gradually during the operation.



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——first step: A quarter of the total steel balls ——second step: Two fourth of the total steel balls ——third step: Three quarters of the total steel balls ——fourth step: All of the steel balls. Important hints:—— The rotation is carried out without coal in order to avoid the fire. —— It is very important to record the quantity of steel ball which had been added in the coal mill. —— The characters (such as absorption power, friction, oil pressure etc.) are recorded during operation. —— The coal mill should rotate for 30 minutes with the maximum amount of load. —— The first ball charge must be carried out through the access door rather than the ball charge system. 4.1 First step 25% steel balls are added in the coal mill in the first step, the following methods are carried out: ——The access door is put upwards under the sound-proof shield through one of the access door, the bearing lubrication system is operated and the shell needs the brake and is locked at this site. The support bearing lubrication is started while the brake is disengaged in order to avoid the frictions between the metals. The grinding mediums are added into the shell with the help of hoisting machine. The access door is fixed on the shell. All the devices (including lubrication system and sealed fan) are started. All the devices are inspected, especially the bearing temperature during the operations. The coal mill is ceased and cooled after the 30 minutes operation. The looseness of the liner bolt is inspected. 4.2 Second step 25% steel ball are added in the coal mill by the above methods and the coal mill is started and inspected. The coal mill stops after 30 minutes operation.



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4.3 Third step and fourth step The entire steel balls are charged by repeating the above steps. The inspections are carried out to the coal mill after the operation and the errors shall be restored and regulated. 5. Inspection before operation

All the devices and components are to be ensured of the normal startup and safe work before operation. Especially the following required inspections: 1) The actions of the coal mill and auxiliary devices, especially the coal feeder, blower, sealed system, coal dust, air, pipe shutoff valve of air and dust mixture and controlled blind. 2) The individual devices must be ensured to be provided with the lubricant system, especially the oil level, pressure, temperature shall be in accordance with the requirements. 3) The temperature, dust delivery system and air system are normal. 4) The remote control is normal. 5）The warning system and safety device should follow the instructions, the range of instruments shall be adjusted to the setting point. 6）The power system such as electric machine is to be ready for the instructions. 7) The measuring instruments, indicator and optional switch of automatic device are in the satisfying state. 8) The enough oil is put into the lubrication system of burner during the entire stage to ensure the smooth burning in the boiler, the boiler burning is raised while in the trouble. 9) The steam inert system can be used while the coal mill is on fire. Any abnormal occurrence which is not accordance with the normal requirements shall be recorded in the device and main control room recording, the shutting down or close watching shall be decided for the grave circumstance and error. Thus, the responsible operator could understand the circumstance, the allowed scope of the above circumstances and the methods which is carried out should be recorded while overrunning the scope. 10) The no coal warning device of the coal feeder is inspected.



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11) The outlet valve of coal feeder is started. 12) The water cooling system of the lubrication device is inspected, and the inspection is carried out to the water cooling which should pass the pipeline. 13) The sealing system is adjusted to the starting state. 14) The sites are inspected for the door and baffle plate of the entire air and pulverized coal pipe. 6. Startup of coal mill without coal

6.1 Startup of the first coal mill after the combustion of fuel The meaning of “coal mill without coal” is that the coal mill has coal, but after the period of stall, the amount of coal may reduces because of the wind. The following advises are applicable to the thermal and cool state coal mill, the difference is that the operation time of cool state coal mill(the stable adjustment for flow rate and temperature) is longer than the thermal state coal mill , the stable grind time must be considered. The operator must ensure the sufficient load of boiler before the combustion of coal in order to avoid the danger which could be caused by the fuel in the boiler during the period of startup. The first startup must be careful. The boiler must work on the upmost ability of the fuel device. Then, as the short instability of the combustion, the amount of reduced fuel is ensured by text in order to avoid the danger to boiler. After all the chapter 3 requirements are achieved and the interlocking mechanism can be used and be operated completely, the coal mill can be started. The startup of coal mill without coal and the restartup are carried out in accordance to the following steps. 6.1.1 The control of all the milling system is installed on the automatic control procedure. 6.1.2 The control baffle plates which are provided with the air system, coal dust pipe, raw coal pipe and ball charge system are closed.



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6.1.3 The temperatures of all the devices are inspected. 6.1.4 Startup of lubrication system Note: The low pressure pump of the main bearing lubrication system is started before the last several hours startup. Under the normal conditions, the pump keeps working even in the period of stop. The pump stops working only while the longtime stop and maintenance. 6.1.5 The low-speed device is closed after a few minutes startup, if the doubt about the rotating flexibility of coal mill is there. 6.1.6 The output system of instrument which measures the pressure and coal level is inspected. 6.1.7 The fire protection system of coal mill can follow the working instructions. 6.1.8 The sealed air fan of the gear cover is started. 6.1.9 The valve under the raw coal bin is opened. 6.1.10 The burner is combusted by fuel oil while the startup of coal mill is ensured. 6.1.11 The primary air fan is started. 6.1.12 The air flow rate and pressure in the bellows are inspected. 6.1.13 The inspection is carried out to the primary air temperature which should be higher than 150 ℃ at the air preheater outlet. 6.1.14 The coal mill is started by the automatic procedure. 6.1.15 The inspections are carried out to the primary air volume (include the air volume of coal mill and bypass) which should be more than the minimum flow rate.



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6.1.16 The automatic purge device of the coal level detection system is inspected. 6.1.17 The temperature of the classifier setting value is inspected. 6.1.18 After the classifier outlet temperature reaches to the enough degree (110℃) for 2 minutes or the coal mill is started for nine minutes, the rawfuel feeder is started and is set in the state of coal supply. 6.1.19 The temperature of the classifier outlet is monitored, if the temperature is abnormal, the flow rate of raw coal must be adjusted, the stability and performance of the combustion are inspected and the inspection is carried out to the secondary air volume of burner in order to reach the good combustion state. 6.1.20 When the electric ear sign is lower than 35% for two minutes, the coal level is controlled by coal feeder 6.1.21 The coal mill load is added progressively, controlled by automatic procedure and continued to increase in accordance with the control requirements, the secondary air passed burner is inspected. 6.1.22 The purge wind should purge the detecting device of coal level control system at regular intervals. 6.2 Startup of coal mill without coal besides the first coal mill The general inspection is carried out to the coal mill in accordance with the regulations of the third chapter and fifth chapter, before the startup of remaining coal mill which follow the first coal mill. The boiler load is inspected and the steps in the 6.1 paragraph are carried out after the boiler program permits the startup of coal mill. 7. Startup of Coal Mill with Coal



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The coal mill is started under the coal feeding conditions (the abnormal stop or devices trip), before the startup, the inspections are carried out to the coal mill in accordance with the requirements of the fifth chapter. The boiler load is inspected and the following steps shall be carried out after the program permits the startup of coal mill. 7.1 Startup of first coal mill (no operations of other coal mills). 7.1.1 All the controls to the relevant coal mill milling system are set on the automatic control program. 7.1.2 Startup of coal mill burner, the stability of firing combustion is inspected. 7.1.3 Startup of primary air fan. 7.1.4 The works for coal level detection system are inspected. 7.1.5 Inspections are carried out to the lubrication system. 7.1.6 Startup of coal mill. 7.1.7 The temperature of classifier outlet is normal. The primary air flow is higher than the minimum value. 7.1.8 Monitoring is carried out to classifier temperature and the adjustment can be carried out to the raw coal flow if the temperature is abnormal. 7.1.9 If necessary, the manual operation could be carried out to keep the control normal and eliminate the errors which could effect the coal mill operation. Warning: If the error of coal feeder makes the stop of coal mill and the coal feeder can not be used at once, the restart-up of coal mill is prohibited. 7.2 Startup of remaining coal mill.



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The protective measures are carried out before the operations in accordance to the steps of 7.1 sections to start oil burner which fits the coal dust burner. The oil combustion load must keep the combustion stable. 8. Shut down

The boiler load requires that the coal mill can be shut down systematically or by force in the emergency, such as a sudden tripping which is caused by the startup of safety interlock. When the coal mill shuts down, the coal mill inside is full of pulverized coal (all or part of pulverized coal), the coal mill can be operated continually by the low-speed device which should operate about 6 hours to avoid the fire in coal mill. If the time of stop is short (less than 40 hours), the coal mill can be shut down with full load. If the time of stop is long (more than 40 hours), coal mill can be shut down after10 minutes operations without the coal feeding to keep the coal mill empty. Before the maintenance, the coal mill must be empty, when the coal activity is high, coal mill must be emptied in the inert gas conditions (mixture of pulverized coal, primary air and steam). While the low-speed device or steam inert system can not be used, the coal mill can be shut down after it was empty. The coal mill with coal can be shut down by low-speed device because of the tripping. During the period of stop, the shell temperature of milling system must be kept under observation in order to find the abnormal occurrence or ignition danger. The coal mill must combust before the stop operation, otherwise the fuel burner is operated, and all the fuel burner must be kept on working by force until the pulverized coal pipeline is clean. 9. Emptying the Coal Mill

9.1 Partial emptying (10 minutes)



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The operations are carried out in accordance with the following steps: 9.1.1 The pulverized coal burner is closed, the combustion of coal mill adopts fuel burner and the load of coal mill could keep the combustion stable. 9.1.2 The stability of the fuel burner combustion is inspected. 9.1.3 The primary air flow is controlled by hand. 9.1.4 The coal feeder is shut down and the outlet gate of coal feeder is closed. 9.1.5 The primary air flow is reduced progressively to the permissible minimum flow. 9.1.6 The temperature of the classifier outlet is monitored and the temperature is stabilized on the normal value by hand. 9.1.7 After 10 minutes of shutting down the coal feeding, the primary air gate is closed. 9.1.8 The main motor of coal mill is closed and the low-speed motor is started. 9.1.9 Startup of the steam inert system (last 3 minutes). 9.1.10 The stop valve of pulverized coal is closed. 9.1.11 While the coal mill is shut down, the fuel burner can be closed after make sure that other burners can keep the combustion stable. 9.2 Complete emptying 9.2.1 The pulverized burner is closed, the burner combustion is adopted and its load should keep the combustion stable. 9.2.2 The stability of fuel burner combustion is inspected.



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9.2.3 The primary air flow is controlled by hand. 9.2.4 The coal feeder is shut down and the outlet valve of coal feeder is closed. 9.2.5 The heat air baffle plate is closed, the steam valve is opened. 9.2.6 After 30 minutes stop of the coal feeding, the seam valve and primary air gate are closed. 9.2.7 The main motor of the coal mill is shut down. 9.2.8 The seal air fan is shut down. 9.2.9 The stop valve of pulverized coal is closed. 9.2.10 While the coal mill is shut down, the fuel burner can be shut down after make sure that other burners can keep the combustion stable. 9.3 Sign when no coal in the coal mill The assurance is confirmed by the following observations after the stop. 9.3.1 Low coal level is detected by coal level control system. 9.3.2 High noise level. 9.3.3 The difference in temperature between the coal mill inlet and classifier outlet has a sharp drop. 9.4 Sign when overload 9.4.1 High coal level is detected by coal level control system. 9.4.2 Low noise level. 9.4.3 Pressure drop of the coal mill is very high.



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9.4.4 Absorption power increases. 9.5 Ball Charge during operation

9.5.1 Since the steel balls will be worn out during operation, new ones shall be charged into the shell regularly in order to fulfill the output capacity and the PC fineness. 9.5.2 During operation, the steel balls are charged into the shell by ball charging device when the the operation of the coal mill is not stop. 9.5.3 If tge current of the main motor is increased or the output is decreased, the new steel ballsshall be charged. The quantity of the new steel balls is based on the current-quantity curve chart during the test of the steel ball charging. 9.5.4 When the new steel balls are charged into the shell by ball charging device, only the φ50 steel balls is needed. Each charge shall be less than 50kg. If the charging quantity is large, then it shall be separated by several times in order to avoid damage to the ball charging device or blockage of the pipe. 9.5.5 The valve of the ball charging device is controlled by the local control cabinet of the ball charging device. First, 50kg of steel balls shall be added to the ball container from the 13.7m operation floor manually. Then open the upper layer valve. When all the steel balls are into the ball container, the upper layer valve is closed. After that, open the lower layer valve so that the steel balls inside the ball container can be dropped into the shell through the pipe. Finally, close the lower layer valve. The above procedure is a complete ball charging procedure for one time. The name and the instruction



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of the equipment refers to VA1-NHI-00100-M-M1C-DGA 2012 BALL CHARGING DEVICE. 9.5.6 If new steel balls are still needed to charge, please repeat item 9.5.5.

Check Sheet for Non-load operation of main motor (without coupling) Unit

System

Equipment Name

KKS

Test Date

Rated Voltage

Rated Current

Rated Speed

Running Current

Main Motor of Ball Mill

Megger Value of motor before run ： Direction of Rotation MΩ Measurement and Tool Insulation Resistance: measured by operator at site with megger ( megohmmeter). Vibration velocity: measured by operator at site with vibration meter. Temperature: indicated on local control cabinet or DCS. Vibration velocity

Time

Location Direction axial direction Vertical horizontal axial direction Vertical horizontal

Temperature

Bearing Temperature Oil Temperature

Shaft

Countershaft End

mm/s mm/s mm/s mm/s mm/s mm/s Ambient Temperature

Time Location

Winding Temperature

Main End

0.5h

1h

1.5h

2h

3h

4h

DCS Reading/ Local Reading

1 2 3 1 2

Measured by：

Company：

Signature：

LLM/Vendor ：

Owner/Consultant：

Signature ：

Trail Run Check Sheet for Main Motor (connected to ball mill) Unit

System

Equipment Name

KKS

Test Date

Rated Voltage

Rated Current

Rated Speed

Running Current

Megger Value of motor before run

Main Motor of Ball Mill

MΩ

Measurement and Tool Insulation Resistance: measured by operator at site with megger ( megohmmeter). Vibration velocity: measured by operator at site with vibration meter. Temperature: indicated on local control cabinet or DCS Vibration

Time

Location

Main Shaft End

Countershaft End

Direction axial direction Vertical horizontal axial direction Vertical horizontal Temperature

Ambient Temperature

Time Location

Winding Temperature Bearing Temperature Oil Temperature

mm/s mm/s mm/s mm/s mm/s mm/s

0.5h

1h

1.5h

2h

3h

4h

DCS Reading/ Local Reading

1 2 3 1 2

Measured by：

Company：

Signature：

LLM/Vendor ：

Owner/Consultant：

Signature ：

Check Sheet for Ball Charging Test Operation (1) Unit

Equipment Name：Ball Mill

System

KKS

Test Date

Measurement and Tool Jacking Height: measured by operator at site with dial indicator. Pressure at high-pressure pump: indicated on outlet pressure gage of lube station. Jacking Height of Shell & Pressure of High-pressure oil

Item

Continuous working period

Non-load Steel Ball

Stationary State

1/4 Steel Ball Load

Stationary State

2/4 Steel Ball Load

Stationary State

3/4 Steel Ball Load

Stationary State

Steel Ball Load during normal operation

Stationary State

Jacking Height Pressure of High-pressure oil (MPa) （mm） Drive NonDE DE NDE NED End Drive instantaneous stable instantaneous stable End peak value value peak value value

Measured by：

Company：

Signature：

LLM/Vendor ：

Owner/Consultant：

Signature ：


System

Equipment Name Ball Mill

KKS

Test Date

Measurement and Tool: Current of main motor: indicated on DCS or other indicator Bearing Temperature: measured by operator at site with thermodetector. Current of Main Motor

A

Item


Non-load Steel balls 1/4 Steel balls load 2/4 Steel balls load 3/4 Steel balls load Steel Ball Load during normal operation

30min 30min 30min 30min 30min

Bearing Temperature

Item

Ambient Temperature


Non-load Steel balls 1/4 Steel balls load 2/4 Steel balls load 3/4 Steel balls load Steel Ball Load during normal operation

Current

Bearing of Pinion Input End

Output End

Bearing Reducer Input End

of

Speed

Output End

Bearing of conveying device DE end NDE end


Measured by：

Company：

Signature：

LLM/Vendor ：

Owner/Consultant：

Signature ：


System

Equipment Name

KKS

Test Date

Measurement and Tool: Vibration velocity: measured by operator at site with vibration meter. Vibration velocity mm/s

Item


Direction

Non-load steel ball

30min

1/4 steel ball load

30min

2/4 steel ball load

30min

3/4 steel ball load

30min


30min

axial direction Vertical horizontal axial direction Vertical horizontal axial direction Vertical horizontal axial direction Vertical horizontal axial direction Vertical

Bearing seat of pinion DE

NDE

shaft extension of speed reducer Inout end Output end

Bearing Sear conveying device DE NDE

Measured by：

Company：

Signature：

LLM/Vendor ：

Owner/Consultant：

Signature ：

of


System

Equipment Name

KKS

Test Date

Measurement and Tool: Vibration velocity: measured by operator at site with vibration meter. Vibration velocity mm/s

Item


Direction

Non-load steel ball

30min

1/4 steel ball load

30min

2/4 steel ball load

30min

3/4 steel ball load

30min


30min

axial direction Vertical horizontal axial direction Vertical horizontal axial direction Vertical horizontal axial direction Vertical horizontal axial direction Vertical

Bearing seat of pinion DE

NDE

shaft extension of speed reducer Inout end Output end

Bearing Sear conveying device DE NDE

Measured by：

Company：

Signature：

LLM/Vendor ：

Owner/Consultant：

Signature ：

of


System

Eqipment Name

KKS

Ball Mill

Test Date

Measurement and Tool Temperature: indicated on local or DCS. Temperature of main motor and main bearing

item

Non load 1/4 load 2/4 load 3/4 load Normal load during operation



Ambient Temperature

Winding Temperature

Bearing temperature of main motor

1

1

2

3

2

Oil Main temperature bearing of ball mill 1

2

Outlet temperature of lube station


System

Eqipment Name

KKS

Ball Mill

Test Date

Measurement and Tool Temperature: indicated on local or DCS. Temperature of main motor and main bearing

item

Non load 1/4 load 2/4 load 3/4 load Normal load during operation


Ambient Temperature

Winding Temperature

Bearing temperature of main motor

1

1

2

3

2

Oil Main temperature bearing of ball mill 1

2


Measured by：

Company：

Signature：

LLM/Vendor ：

Owner/Consultant：

Signature ：

Outlet temperature of lube station

VA1 NHI 00100 M M1C MAN 0003 Rev1 Coal Mill Operation Manual

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