Method for preparing ceramic filter tube for purifying high temperature gas

Abstract

The present invention relates to preparation of filtering ceramic tube, and is especially one kind of filtering ceramic tube for purifying high temperature gas in coal gasifying power generating field and its preparation process. The preparation process of the filtering ceramic tube includes the steps of: preparing liquid phase oxide sintering agent, preparing filtering ceramic tube with SiC particles as the main micro structure carrier, making mullite fiber film, coating film and sintering to obtain filtering ceramic tube product. The present invention has gas passage outside the oxide particle, no residual sintering assistant to ensure the gas passing rate, high mechanism strength of the combined phase, high heat resistance, high chemical stability, easy liquid phase formation, high strength, gas penetrating rate and integrality of the film.

Description

technical field [0001] The invention relates to a preparation method of ceramics, in particular to a preparation method of a ceramic filter tube for clean high-temperature gas used in the field of coal gasification power generation. Background technique [0002] Ceramic filter tubes are used for the filtration of coal gas in high-temperature environments such as coal gasification power generation because of their porous structure and the characteristics of heat resistance, chemical stability and high strength. The preparation of ceramic filter tubes mostly uses SiC particles as the main component, and uses natural materials such as clay and talc as binders to connect SiC particles; because the dust particles to be captured by filter tubes are small in size, membranes must be used at this time. Use ceramic powder to make slurry, and then coat it on the surface of the filter tube with SiC particles as the carrier, form a film, dry and sinter. Histori...

AI Technical Summary

Problems solved by technology

Historically, the filter tube carrier has been made by mixing kaolin clay, talc, calcium carbonate and other natural materials as binders, but the filter tube carrier made by it lacks chemical stability at high temperature and has poor mechanical strength; The forming process adopts extrusion forming or dry pressure forming, and the sintering adopts solid phase sintering or liquid phase sintering, but the extrusion forming and dry pressure forming methods cannot effectively use the surface tension of the liquid phase to form enough SiC particles. In the pore space outside the part of the support, the pressure loss caused by the passage of air is large, and its bending strength is small; during solid-phase sintering, the moving speed of the material is small, and the pore space outside the joint of the support particle cannot be formed too much, and the pressure generated by the passage of air at the same time The loss is relatively large, especially if the casting method is used to make long-sized ceramic filter tubes, its strength and pressure loss caused by air passage are difficult to guarantee; the firing conditions of the membrane require that the membrane must have certain strength, air permeability and integrity, but Due to the difference in shrinkage between the membrane and the ceramic filter tube plain mold during sintering, it is easy to cause cracks

At present, there is no record about the technical scheme of making long-sized ceramic filter tubes and membranes with satisfactory strength.