喷动流化床内木屑流动特性的研究(Ⅰ)

Hydrodynamics of sawdust in a spout-fluid bed with draft tube

为了开发喷动流化床生物质裂解反应器,建立了一内径为150mm的有机玻璃冷模实验装置,考察了喷动气和流化气流速、木屑粒子的加入量及导向管位置对床层流动特性的影响。发现喷动气的旁路现象对粒子循环速率、中心喷泉高度及床层压降都有显著影响。流化气的加入,可抑制喷动气的旁路趋势。实验还发现,木屑粒子与煤粒这类刚性粒子的流动特性不完全相同,木屑粒子之间相互作用较大。

A 150 mm diameter cylindrical apparatus was used to investigate the effect of operating and geometric parameters on the hydrodynamics of spouted-fluidized bed with a draft tube at ambient temperature. The results show that the solid circulation rate, fountain height and bed pressure drop were all significantly influenced by the bypassing characteristics of the spouting gas. The introduction of fluidizmg gas is helpful to decrease such bypassing. The effects of draft tube location and solid particle loading on the bed hydrodynamics are discussed. It was also found the flow characteristics are not totally same between sawdust particles and rigid particles such as coal grain. Interaction between sawdust particles is much significant.