A high-temperature-resistant, stain-resistant and slagging-resistant ceramic coating and its preparation method and application

Abstract

A high temperature-, stain- and slagging-resistant ceramic coating and a preparation method and use thereof. The ceramic coating comprises the following components by mass percentage: 15-30 percent of a filler, 40-65 percent of an adhesive agent and the balance being water, wherein the filler comprises 3-5 percent of zirconia, 3-5 percent of silicon carbide, 3-5 percent of silicon nitride, 1-3 percent of titanium dioxide, 2-4 percent of kaolin and 3-8 percent of a rare earth oxide. The preparation method thereof comprises the steps of mixing the adhesive agent with water to prepare an adhesive agent liquid, then adding the filler refined to a particle size up to 50-900 nm to the adhesive agent liquid, and then adding an auxiliary, uniformly mixing, filtering and packaging. The coating can be applied on the external surfaces of a boiler tube and a heater tube to form a ceramic coating so as to prepare a boiler tube and a heater tube having high performance.

Description

technical field [0001] The invention belongs to the technical field of special coatings, and in particular relates to a high-temperature-resistant, stain-resistant and slagging-resistant ceramic coating as well as its preparation method and application. Background technique [0002] In the production and operation of power station boilers, petroleum and petrochemical heating furnaces, and small and medium-sized industrial boilers, the contamination of pulverized coal boilers (including fuel gas heating furnace tubes) has caused great hidden dangers to the safe operation of boilers, and at the same time affects the efficiency of boilers and heating furnaces. Under the action of flue gas, the ash and slag bonded to the water wall or high temperature superheater and the furnace tube of the heating furnace will undergo complex chemical reactions with the tube wall to form high temperature corrosion. Contamination and slagging are generally considered to be the prelude to high-te...

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Problems solved by technology

Contamination and slagging on the high-temperature heat exchange surface directly leads to a decrease in the heat exchange capacity of boilers and heating furnaces, a reduction in furnace efficiency and output, and uneven heating of the heat exchange surface leads to uneven thermal stress of the furnace tube and uneven heating of the heated working medium. The rise in temperature leads to overheating of the furnace tube, the generation and emission of nitrogen oxides intensifies, and the exhaust gas temperature is too high. Contamination and slagging aggravate the corrosion of the heat exchange surface. Production capacity, reduce the service life of equipment, and bring heavy losses to the enterprise

[0003] For contamination and slagging, the traditional solution is to strengthen soot blowing, adjust fuel, put into operation decoking agent, mechanical coking, etc., which will bring continuous economic losses to enterprises, and safety hazards still exist

[0004] As a new type of functional material, ceramic coatings can resist high temperature corrosion and increase emissivity, but the existing ceramic coatings cannot solve the problems of high contamination and high temperature corrosion, especially reductive corrosion, so the above functions cannot be realized comprehensively , and there are cracks, peeling, and pulverization of the coating to varying degrees during use, which seriously affect the service life of the coating. At present, these problems cannot be effectively solved

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