流化床燃烧棉秆的混合特性及床料的选择

Mixing Properties of Cotton Stalk Burnt in Fluidized Beds and Choice of Bed Material

在0．2MW热功率的试验台上进行了燃烧试验，研究了棉秆长度、床料粒径、配比和流化速度对混合均匀程度的影响。试验结果表明：①长度10～100mm特别是50mm左右的棉秆，与中0．6～1mm床料能均匀地混合。当床料重量比为2％，在流化数为3～7时，能均匀地混合流化；但流化数大于7时，混合的均匀度稍有降低，棉秆与床料的配比对混合也有影响。②棉秆流化床燃烧宜选择弱酸性床料，不会出现烧结现象而影响床料的正常流化。

Combustion tests have been performed on a test rig of 0.2 MW thermal output. The main topics of study were the influence of stalk length, bed material＇ s particle size, mass percentage and fluidizing velocity on mixing uniformity. Results indicate that： ① cotton stalk of length 10 - 100 mm, especially around 50 mm, can uniformly mix and get fluidized with a bed material of grain size 0.6 - 1 mm for a weight proportion of 2 % and a fluidization number above 3. But uniformity reduces somewhat as soon as the fluidization number exceeds 7. Proportions of cotton stalk to bed material have also a certain influence on mixing. Therefore the fluidizing velocity and the static state bed height should be chosen reasonably when designing fluidizing bed boilers. ② It was found that, when firing cotton stalk in fluidizing beds, weak acidic bed materials should be chosen, and normal fluidization of the bed material will not be affected by sintering.