Effects of Raw Material on Combustion in Circulating Fluid Bed(CFB)

Efficient conversion of straw materials for energy purpose has provided one ideal solution in wastes utilization and environment protection.The combustion characteristics of agricultural wastes in circulating fluid bed(CFB) were investigated with rice hull as the feedstock.On basis of long duration successive test with one pilot scale test facility,the effects of fluidizing velocity,particle size and air distribution on the combustion behavior were discussed in detail,as well as agglomeration phenomenon in straw material combustion.The variation of fluidizing velocity was found to be proportional to the variation of combustion efficiency in certain ranges.However,particle size was inversely proportional to combustion efficiency.And it seemed that the best ratio of secondary air in total air output was 50~70 percent for steady CFB operation In order to avoid the high temperature agglomeration in combustion process of straw materials in CFB,the operation temperature should be kept at below 900 ℃,with relatively uniform temperature distribution in CFB reactor under 850 ℃.