April 8, 2022
Gasifier lining atmosphere is different, the use of castable is also different. Zirconia series refractory castables are used for oxidizing atmosphere and silicon carbide series refractory castables are used for reducing atmosphere.
Silicon carbide series castable have the advantages of corrosion resistance, high wear coefficient. It is very effective in reducing melting loss. Moreover, silicon carbide castables have the advantages of high thermal conductivity and good thermal shock resistance. It is best used in reducing atmosphere gasifier lining.
The upper temperature of the gasifier is low, and the material is sprayed with high strength. Near the tuyere, due to the thermal decomposition of the residual solids, ash melting serious, and side wall parts are also used silicon carbide series of refractory castable.
Furnace is oxidation atmosphere, will produce slag alkali erosion, the general use of al2o3-Cr2O3 series of refractory castable, but also useful castable containing chromium oxide properties, this castable slag resistance ability, good corrosion resistance. But the porosity will be higher. Will be in the furnace temperature fluctuation, caused by the thermal spalling or by the influence of slag infiltration, resulting in structural spalling, damaged lining. Also, chromium oxide is rarely used because of its toxic properties.
The addition of zirconia castable can greatly improve the spalling resistance, and the effect of erosion resistance and slag resistance of castable is good.
What kind of refractory castable is used for gasification furnace lining determines the service cycle and cost control. When choosing castable, the operating atmosphere and slag composition of the furnace should be carefully studied. To choose between silicon carbide castable or zirconia castable series.
Because the furnace lining atmosphere is different, can not use the same series of refractory castable, after distinguish the atmosphere, choose the appropriate series of castable as lining, not only increase the use time of furnace lining, but also save the production cost.