Light heat insulating castable for lower part of CFB circulating fluidized bed separator and preparation method thereof

Abstract

The invention discloses a light heat insulating castable for the lower part of a CFB circulating fluidized bed separator and a preparation method thereof. The castable comprises a light framework material, a wear-resistant heat-insulating material, a bonding sizing material, a composite additive and deionized water; the preparation method of the castable comprises the following steps: S1, carrying out coarse crushing, calcination and fine powder treatment on the light framework material to obtain powder; then adding part of deionized water into the powder, and extruding to obtain a light framework material precursor; and finally, drying and baking the light framework material precursor to obtain the light framework material. S2, calcining and crushing the wear-resistant heat insulating material to obtain a heat-treated material; s3, uniformly mixing the heat-treated material with a bonding sizing material, a composite additive and the rest of deionized water to obtain a premix; s4, stirring and fusing the premix and the light framework material obtained in the S1, and obtaining a casting material; the castable prepared by the method has the advantages of light weight, low thermal conductivity and strong wear resistance, and is suitable for large-scale popularization.

Description

technical field [0001] The invention relates to the technical field of lightweight thermal insulation castables, in particular to a lightweight thermal insulation castable for the lower part of a CFB circulating fluidized bed separator and a preparation method thereof. Background technique [0002] Circulating fluidized bed combustion technology is a new type of coal-fired technology. The materials in the boiler have the characteristics of high heat capacity, strong mixing, and low-temperature combustion. This combustion technology has strong adaptability to fuels. It can not only burn lignite, bituminous coal, Anthracite, coal gangue, gas-making slag, petroleum coke and other low-quality fuels, and multiple types of coal can be burned on the same boiler at the same time; it can also achieve clean combustion of coal, and achieve high-sulfur coal by adding limestone powder or calcium carbide slag The flue gas desulfurization in the furnace is beneficial to the comprehensive u...

AI Technical Summary

Problems solved by technology

[0004] At present, the most popular circulating fluidized bed separator with the highest share in the international and domestic markets is a high-temperature cyclone separator made of refractory materials. Its main advantage is high separation efficiency, and its main disadvantages are bulky size and high wind speed at the tangential inlet of the separator. , high resistance, high power consumption of induced draft fan, high-speed flow of gas-solid two-phase toward the silo air flow reversely entrains a large amount of fly ash, and the original emission concentration of smoke and dust is high. The separator needs inner lining and outer heat insulation. The large amount of high-temperature grinding materials not only increases the cost of raw materials and manufacturing and installation of the separator, but also increases the thermal inertia, which is easy to coke at high temperature and slows down the boiler start-up and shutdown.

Some boilers use water-cooled or steam-cooled cyclone separators. Although the wear-resistant and high-temperature resistant materials are reduced, the problem of large thermal inertia is solved, the boiler does not coke, and the start and stop are fast, but there are also high wind speeds, large resistance, and induced draft fans. The power consumption is high, and the separation efficiency and stability are lower than those of cyclone separators made of wear-resistant high-temperature materials. In addition, the manufacturing process is complicated, resulting in high prices, which are not easy for customers to accept, and the market share is very low.

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