在内径为182 mm的喷动流化床中安装内径80 mm的导向管,以平均粒径为2.2 mm的尿素颗粒为物料,对喷动气旁路特性进行了实验研究,分别考察了夹带区高度、导向管长度、喷嘴内径、床层高度、喷动气速和流化气速对喷动气旁路分率的影响,结果表明随着喷动气速的增大,喷动气体旁路分率先增后减.导向管安装高度越高,气体旁路分率越大.床层高度增大喷动气体旁路分率略有降低.而喷嘴直径小于50 mm时气体旁路分率随喷嘴直径增大而提高,在大于50 mm时气体旁路分率随喷嘴直径增大维持不变.当气速较小时,导向管高度增大会引起气体旁路分率增大,引入少量流化气能有效地抑制喷动气旁路.%A cylindrical spout-fluid bed (182 mm inner diameter) equipped with a 80 mm inner diameter draft tube and loaded with urea particles (2. 2 mm average particle size) was used to study gas bypassing fraction of spouting gas. The effects of spout nozzle diameter, draft tube length, bed height, entrainment height, spouting velocity and fluidizing velocity on gas bypassing fraction of spouting gas were investigated. The results showed that with increasing spouting velocity, gas bypassing fraction increased first and decreased later. Gas bypassing fraction increased with increasing entrainment height, but decreased slightly with increasing static bed height. When spout nozzle diameter was less than 50 mm, gas bypassing fraction increased with increasing nozzle diameter, but remained unchanged when nozzle diameter was greater than 50 mm. When spouting velocity was low, gas bypassing fraction increased with increasing draft tube length. The introduction of a small amount of fluidizing gas could effectively suppress gas bypassing.
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