1) One step kiln drying with simultaneous kiln drying and kiln opening
Firstly, the ash discharging mechanism at the kiln bottom, such as the ash discharging screw cone, ash tray or pallet type ash extractor, shall be covered with lime blocks with a certain thickness and appropriate particle size for protection. Firewood shall be stacked on the formed protective layer, and ignition holes shall be reserved. Stack an appropriate amount of coke on the firewood and add the mixture of limestone and coke on the coke layer to ignite and dry the kiln. After the fire, the air supply volume shall be controlled, and the temperature rise shall be slow and uniform. The temperature measuring points and the total drying and opening time can be determined by referring to the existing experience of drying and opening lime kilns with similar performance, and the drying curve can be formulated for drying operation. After the temperature rise process of the drying kiln is stable, the materials can be gradually added and put into production.
2) Two step kiln drying with kiln drying and kiln opening separately
According to the specific conditions of the kiln construction site, select a suitable heating method for kiln drying (for example, a small coke furnace is usually built in the kiln, and warm air can be sent when conditions permit), so that the temperature in the whole kiln can reach and maintain around 150 ℃ for about two weeks, so as to dry the free water in the masonry and avoid the kiln lining masonry from freezing in winter.
After the completion of the kiln drying process and passing the inspection, the kiln can be started as required according to the method in the preceding paragraph.
- precautions for refractory brick kiln drying
1) The reasonable drying curve and drying operation procedures shall be formulated according to the size of the kiln body, the structure of the kiln body, the variety of refractory materials selected, the kiln environment and the different construction seasons.
Kiln drying curve includes: kiln drying period, maximum kiln temperature, heating rate, kiln insulation temperature, insulation time, cooling rate, etc.
When the kiln lining is a refractory castable, the kiln drying curve shall also be formulated according to its material, thickness and forming process.
When the kiln lining is composed of different kinds of refractory materials, the kiln drying curve shall be formulated according to the material characteristics and the primary and secondary relationship.
2) Representative temperature measuring points should be set at appropriate parts of kiln lining to monitor and control the temperature required for kiln drying.
3) The temperature rise of the kiln shall be uniform and slow. Sudden temperature rise or drop is strictly prohibited to avoid damage to the refractory lining or nodulation caused by local overheating.
4) In the process of kiln drying, if a fault occurs that affects the normal temperature rise, insulation measures shall be taken immediately, and the temperature rise can be continued only after the fault is eliminated.
The kiln drying process shall be recorded in detail. In case of any abnormal phenomenon, corresponding countermeasures shall be taken and the reasons shall be noted.
5) During kiln drying, the kiln temperature shall be measured and recorded as required, and the actual kiln drying curve shall be drawn.
6) After the completion of kiln drying, after the temperature of the kiln drops to normal temperature, relevant personnel must be organized to enter the kiln for cleaning and inspection in time, and the defects can be put into production only after they are corrected.