Drying-out of newly installed refractory materials SF and CB cooler, kilnhood and tertiary air duct Original instructions
Erection, Operation and Maintenance, Safety
Approved date:19th Jan 2012 Created by: TMN-IN Approved by:Klkr
Doc. No.: 70001614-1.55
Drying-out of newly installed refractory materials 70001614-1.55
Page Table of contents 1 General information information ....................................................................................... 3
2
1.1 Scope........................................................................................................... 3 1.2 Definition and abbreviation ............................................................................. 4 1.3 Legend ......................................................................................................... 4 The drying-out process .................................................................................. 4
3
Heating up ................................................................................................... 4 3.1 3.2
4
Equipment .................................................................................................... 4 Preparations ................................................................................................. 5 3.2.1 SF and CB Cooler grates ..................................................................... 5 3.2.2 Bulkheads ......................................................................................... 5 3.2.3 Further draft control ...................................... .................. ........................................ ..................................... ................. 5 3.2.4 Thermocouples .................................................................................. 5 3.2.5 Burners ............................................................................................ 6 3.2.6 Fuel supply ....................................................................................... 7 3.2.7 Weep holes ....................................................................................... 7 3.3 Firing ........................................................................................................... 7 Suggested suppliers ...................................................................................... 8
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The information transmitted by this document is the proprietary and confidential property of FLSmidth and may not be duplicated, disclosed or utilized without written consent from FLSmidth.
Drying-out of newly installed refractory materials 70001614-1.55
NOTE ! The present instruction manual is concerned with the situations which, according to the experience of F. L. Smidth, are the most likely to occur. An exhaustive enumeration of all conceivable situations, which may occur during manufacture, installation, operation and maintenance of the equipment, cannot be provided.
Consequently, if a situation should arise, the occurrence of which is not foreseen in the instruction manual, and which the operator is/or feels unable to handle, it is recommended that F. L. Smidth is contacted without undue delay for advice on appropriate action.
1 General information 1.1
Scope
Mandatory! The local safety legislation for the mentioned equipment must be followed to any time. The supplier’s instructions for the equipment must be carefully studied and followed. During the drying-out operation, all openings must be closed and adequate precaution must be taken to prevent any unauthorized opening of such openings. Attention must be given to the risk of personnel being trapped inside the equipment during drying out. Before the drying-out begins and the manholes are closed, an authorized operator must make sure that all workers has vacated the equipment. equipment.
If a newly installed lining is heated up too quick one might expect steam explosions within the lining. The free water will have left the lining when heated above 100 o C. But plastic refractories still contains chemically bonded water until 500 oC. In order to let the water leave through the pore structure without making damage, the initial heating up process should be controlled. The supplier of lining materials and installation will mostly have their own drying-out instructions and these should always be followed. In absence of any instructions, the general methods mentioned in the following should be applied. The drying-out of the kiln and preheater can be done with the main burner, but the drying of the cooler, kilnhood and tertiary air duct must be done with auxilery burners. The drying-out process is to be applied to newly installed linings both in new plants and major repairs.
The information transmitted by this document is the proprietary and confidential property of FLSmidth and may not be duplicated, disclosed or utilized without written consent from FLSmidth.
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Drying-out of newly installed refractory materials 70001614-1.55
1.2
1.3
Definition and abbreviation Authorized person
An authorized person is a skilled person, who is qualified and who by either the responsible manager or a qualified person is entrusted with certain tasks.
Certified person
A person who is skilled and authorized from any legal authority to perform tasks, which must be certified by a third party or which requires a legal authorization to perform.
Legend
Mandatory! This symbol appears in the instruction manual to indicate dangers which, in case of non-observance, may cause fatal or serious injuries!
Attention! This sign is shown in the instruction manual where specific attention and caution is needed to avoid damage to or destruction of the equipment and/or parts of the installation.
2 The drying-out process After a preliminary curing at ambient temperature in 24 hours, the lining should be heated to 500 oC over a period of 96 hours. The temperature is raised with adequate holding ramps during the period, allowing the temperature to soak into the material. The main burner should be applied in direct continuation of the drying-out process.
3 Heating up 3.1
Equipment The must recommendable way to get the drying-out job done is to let a company specialized in the job to do it. When supplied with drawings of the machine and heating curves for the materials, they will supply the equipment, manpower and know-how for the job. If you have to supply your own equipment, the best way is to use a unit including burner, oil pump, air fan and flame surveillance. The equipment for the job should at least consist of the following: High velocity gas- or light oil burners with flame surveillance, ignition and manual operated fuel- and air valves. The burners must be equipped with heat resistant nozzles. The size and numbers of burners needed for the job, depends of the size of equipment to be dried-out. But a total effect of the burners will often be in the range of 2-5000kW.
Mandatory! The burners must comply with local safety legislations!
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The information transmitted by this document is the proprietary and confidential property of FLSmidth and may not be duplicated, disclosed or utilized without written consent from FLSmidth.
Drying-out of newly installed refractory materials 70001614-1.55 One fuel tank with a capacity of 3000 litre oil or a volume of gas with similar energy potential. The tanks should be refilled during the process. One air fan for each burner with a capacity matching the applied burners. In case of oil burners: Oil pumps with a capacity matching the burners’ requirements, plus pressure to compensate for the transport from the tank to the burners. Fuel and air hoses to compensate for the distance between the burners burners and fuel/ air supply. The hoses must be able to with stand the fuel pressure. High pressure fittings for the for the fuel transport system. Thermocouples with corresponding type of compensation cable and reading instruments calibrated for the actual type of thermocouble. The CrNi-Ni type of thermocouple thermocouple is adequate for the actual temperature range.
3.2
Preparations
3.2.1
SF and CB Cooler grates To protect the grates for the heat and limit false draft, the grates must be covered with app. 400mm clinker or mineral wool etc..
3.2.2
Bulkheads To ensure correct draft and heat accumulation, loosely constructed bulkheads of a light refractory insulating material should be erected in the kiln outlet and other places where draft is not desired.
3.2.3
Further draft control Further draft control can be achieved by opening man doors in the preheater tower and using the hoisting damper in the tertiary air duct.
Mandatory! If it is necessary to use man doors for further draft control, access through the man doors must be avoided by screening them off in a secure manner.!
3.2.4
Thermocouples Thermocouples should be installed at the following points: Cooler, Kilnhood and tertiary air duct. The thermocouples hot point should be in the same level as the hot face of the lining. In order to protect the cooler grates; the temperature readings for the grates should be checked regularly, either in the control room or by placing a thermocouple under the clinker layer. For correct readings it is important that the thermocouple and the reading instrument are connected with the correct type of compensation cable. If remote readings are preferred, common cable can be used between the reading instrument and a terminal placed in ambient temperature, the connection between the terminal and thermocouple must be done with compensation cable.
The information transmitted by this document is the proprietary and confidential property of FLSmidth and may not be duplicated, disclosed or utilized without written consent from FLSmidth.
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Drying-out of newly installed refractory materials 70001614-1.55
3.2.5
Burners The burners are placed in the man doors of the cooler; the number of burners depends of the size of the equipment and the effect of the burners. If a burner is placed through the man door behind the crusher, the chain curtain should be pulled aside and fixed in a manner making it possible to release it without entering the cooler. Additional burners can be placed through the main burner hole and at the man door in the tertiary air duct. The man doors are bricked just leaving an opening big enough to let the burner nozzle pas through and a spy hole from which the flame can be observed. The burners are placed at thresholds, with the nozzles protruding far enough into the cooler, to avoid direct flame heat on the steel frame of the man door. The burners are connected with the fuel and air supply and the control unit.
Bulk head Burner nozzle Flame
Ceramic fibre
Figure 1: Burner installation.
1
Burner
2
Thermocouple
3
Bulkhead
4
Kiln
5
Tertiary air duct
6
Kiln hood
7
Cooler
8
Chain curtain
9
Clinker layer
Figure 2: Suggestions for placement of burners, bulkheads a nd thermocouples. 6/8
The information transmitted by this document is the proprietary and confidential property of FLSmidth and may not be duplicated, disclosed or utilized without written consent from FLSmidth.
Drying-out of newly installed refractory materials 70001614-1.55
3.2.6
Fuel supply The fuel is supplied from one central tank, which is easy accessible for refueling. The oil is transported to the burners by the oil pumps and hoses, make sure that all connections are tightened sufficiently. The gas is supplied from the plants main supply.
Mandatory! All gas connections must only be done by certified personnel.
3.2.7
Weep holes To facilitate the steam to escape, it is advisable to drill some weep holes in the steel casing. The holes are suggested to be Ø12 and placed with a density of one hole per square metre. The holes are made where large quantities of steam are likely to escape, for example roofs, walls at the kiln end and around the wear curbs.
3.3
Firing Once the firing has started it should not be interrupted. Sufficient personnel must be allocated to take care of the process 24 hours/ day in the 4 days the drying-out takes. The temperature, burners, fuel tank and all connections must be controlled every hour. The burners should burn with a clear flame. If the flame becomes smoky, the air must be regulated upwards until the flame just turns clear. The temperature is raised to 120 oC in the beginning of the first 24 hours period and kept at this temperature to the end of the 24 hours period. During the next 24 hours periods the temperature is raised to 2-, 3-, 4and 500oC.
Temprature rise 600
C 500 o
e 400 r u t 300 a r p 200 m e t 100 0 0
4
24
30
48
58
72
80
96
hours
Figure 3: Heating curve. At the end of the drying-out programe, program e, the bulkhead at the kiln outlet is demolished, the auxilery burners in the kiln hood removed and the kiln is The information transmitted by this document is the proprietary and confidential property of FLSmidth and may not be duplicated, disclosed or utilized without written consent from FLSmidth.
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Drying-out of newly installed refractory materials 70001614-1.55 stated according to the kiln’s process instruction. At the time when the clinker is about to reach the cooler, burner equipment and bulkheads are removed and the man doors are closed and secured.
4 Suggested suppliers Following companies are well known by FL Smidth and can be used as drying-out specialists for complete drying-out jobs: Hotwork International Thermal Hire, UK Secatherm, France
Following companies are well known by FL Smidth and can be used as suppliers for drying-out burners: Thermal Hire, UK Weishaupt, Germany ---o0o---
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The information transmitted by this document is the proprietary and confidential property of FLSmidth and may not be duplicated, disclosed or utilized without written consent from FLSmidth.
