What refractory materials are used in fluidized bed incinerators? The application of refractory and wear-resistant materials in circulating fluidized bed incinerators is mainly divided into zones such as wind tunnel, dense phase zone at the bottom of the furnace, combustion zone, feed port, high-temperature cyclone separator, return pipe and so on, and it is necessary to select appropriate refractory and wear-resistant materials according to the atmospheric conditions of each zone.
Generally, refractory brick is suitable for regular-shaped surfaces, while refractory brick or plastic is used for irregular-shaped surfaces where its application is difficult. Water-cooled air chambers are usually designed as lined, single-layer, wear-resistant structures. The material can be made of medium-quality wear-resistant plastic, and the air distribution plate can be made of self-flowing corundum casting material or corundum wear-resistant plastic.
In a fluidized bed incinerator, the density of the bed material and the waste differ significantly. The waste is mainly burned in the dilute phase region. The temperature in the dense phase region is relatively low and the wear is relatively severe. Wear-resistant corundum or plastics are generally used. There is a lack of oxygen required for combustion here, and the reducing atmosphere becomes stronger. In order to improve the material's resistance to CO, the Fe2O2 content in the material must be carefully controlled.
1. The waste discharge and carbon pipe are installed at the junction of the dense phase zone and the lean phase zone. These two parts are subject to wear. It is also possible to combine more wear-resistant corundum with silicon carbide castings or use mixed castings of mullite and corundum.
2. In the combustion zone, that is, above the charging port, the exhaust gas temperature is relatively high, generally above 850°C, and silicon carbide-based wear-resistant refractories and corundum-based wear-resistant refractories can be used.
3. The furnace outlet and separator inlet are parts subject to wear, especially the separator inlet, which can be made of high-strength and wear-resistant silicon carbide bricks or cast bricks. Since the site is uneven, construction techniques and experience are especially important.
4. The return pipe is also an important component of the circulating fluidized bed. It is generally designed as a wear-resistant structure with a multi-layer lining. The materials used are high-strength and wear-resistant refractories and corundum-based wear-resistant bricks, and the specific construction method is determined according to the pipe diameter.
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