喷动流化床内的木屑流动特性——II.导向管长度的影响

Hydrodynamics of Sawdust in a Spout-fluid Bed with a Draft Tube II.Effect of Draft Tube Length

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,在室温下考察了不同喷动气和流化气流速下,导向管长度对床层流动特性的影响。结果表明,在其他条件相同时,颗粒循环量、中心喷泉高度及床层压降随导向管长度增长先增加后减少,本装置中导向管的最佳长度为450mm。另外导向管的长度对床层的稳定性也有一定影响。

To develop the reactor for biomass pyrolysis, a 150mm diameter cylindrical spoutfluid bed contactor with draft tube was established. In this paper, the effect of draft tube length on the hydrodynamics of this contactor was investigated with different spouts and fluid gas velocity at ambient temperature. The results showed that for the length of four draft tubes:350mm,400mm,450mm,500mm, all of the solid circulation rates, fountain heights and bed pressure drops increased from 350mm to 400mm and then dropped from 400mm to 500mm when the other factors were all the same. The length affected the operating stability of the bed also. According to the phenomena of the experiment and the hydrodynamics of spoutedfluidized bed, we found 450mm being the best draft tube length in this contactor.