Grate firing has been the most commonly used firing method for combusting solid fuels in small and medium-sized furnaces since the beginning of the industrialization. Coal, waste and biomass fuels are usually burned in grate boiler. In the chain boiler, the coal is moved backward from the front of the grate, and the air from the bottom up to the furnace, and as the furnace is constantly moving backwards, the fire, combustion, burning and other stages occur in sequence. Traveling or chain grate stokers feed coal out onto a rotating metal belt that supports the fire. Solid fuel is fed from a hopper. Grate speed is automatically controlled to maintain desired steam pressure. Burning progresses as the belt moves from front to back of furnace. Combustion is essentially complete at the back end of belt, and ash is dumped off into an ash pit there.
The United States is our national enterprise, one of the world's top 500, with very bright glory on the world stage. US air-conditioning as a subsidiary branch, with a very large market competitiveness. 2016, Hubei US air-conditioning due to market demand to expand production lines, need to purchase steam 5000 kw biomass fired boiler to provide energy support for the new production line. After the boiler industry for a number of enterprises contrast, is determined to cooperate with the fast boiler, buy a whole 10 tons of steam condensing gas steam boiler (WNS10-1.25-Y.Q).
Multi fuel CFB 5000 kw biomass fired boilers suitable for 100% biomass and 100% coal combustion.Different emission formation mechanism increase challenges for design of fuel,air and emission control additive feeding locations and controls.
Fuel flexibility characteristic for CFB 5000 kw biomass fired boilers plays an important rule in industrial and utility size applications.Possibility to use wider range of fuels that has been long time considered as by-products or wastes and possibility to design boilers able to operate with alternative fuels is an important factor that improves fuel delivery security and plant economy.Presented article is based on similar publications that present Foster Wheeler's experience in design and delivery of the CFB boilers for wide range of coals and cofiring by-products of crude oil refining and coal processing. Aspects of biomass cofiring will be also presented.