As a new type of environmentally friendly boiler, the circulating fluidized bed has a complex structure and contains a large number of high-concentration, high-speed circulating coal particles in the combustion system. This requires that its lining wear resistant refractory castable must first have excellent construction performance, and secondly must have high strength and good wear resistance.
Wear resistant refractory castables are mainly used in parts with complex structures, where vertical casting is possible and vibration is small, such as air distribution plates, header areas at the bottom of the furnace, furnace outlets, cyclone separators, etc. According to the needs of different furnace types and different working conditions, refractory materials with different materials and properties should be used in different parts of the boiler to achieve balanced lining corrosion and improve the comprehensive economic benefits of the boiler.
1) The fluidized chamber is entirely water-cooled, that is, pins are densely arranged on the membrane wall, and then high-strength wear-resistant refractory castables are poured.
2) The structural design of the furnace roof is the same as that of the fluidizing chamber. Generally, high-strength wear-resistant refractory castables are used and hoisted as a whole after pouring on the ground. There are also designs for wear-resistant plastics to be prefabricated on the ground or rammed after hoisting.
3) The water-cooled air chamber has a small space and a complex structure, but is not very susceptible to wear. It is cast and cured on the ground using ordinary wear resistant and refractory castables and then hoisted as a whole.
4) The flue gas velocity at the top of the superheater is high and suffers severe wear, so high-strength and wear-resistant castables are used.
5) The flue gas velocity before entering the economizer is relatively high, so the rear side wall is still made of high-strength wear-resistant castable.
6) The cyclone separator is subject to considerable wear due to the passage of a large amount of high-concentration, high-speed circulating coal particles. In addition, the cyclone separator is a simplified structure, which makes its construction somewhat difficult, so wear resistant refractory castables are used.