栓流密相气力输送特性的试验研究

Research on Characteristics of Plug-flow Dense Phase Pneumatic Conveying

为研究栓流密相气力输送气固两相流的输送特性,进行了粉煤灰在输送管内的流动模式试验和粉煤灰输送压力、物料流量特性试验。采用ECT技术测试了粉煤灰在输送管内的流动模式,并考察了主进气流量、补气流量、助吹气流量对物料流量、固气比的影响。研究表明:粉煤灰在输送管内的流动模式是以栓流密相为主,其灰栓长度为0.8～2.3m,移动速度为2.8～11.3m/s;输送压力与物料流量成双曲线特性,且随着空气流量的增加物料流量增大;主进气流量起主导作用,并与物料流量成单调上升抛物线关系,与固气比成上凸抛物线关系,即先增大后减小。

Experiment was conducted for the flow pattern of fly ash in the conveying pipe and characteristics of fly ash conveying pressure and material flow rate in order to study the conveying characteristics for the gas and solid phases of the plug-flow dense phase pneumatic conveying. ECT technology is used to examine the flow pattern of fly ash in the conveying pipe,as well as influences by main inlet gas flow rate,makeup gas flow rate,auxiliary blowing gas flow rate on the material flow rate and solid/gas ratio. The research indicates:the flow pattern of fly ash in the conveying pipe is mainly plug flow,whose ash plug length is 0.8～2.3 m,and the travelling speed is 2.8～11.3 m/s;the relationship between the conveying pressure and the material flow rate is characterized by a hyperbola,and the material flow rate increases with the increase of air flow rate;the main inlet air flow rate plays the prevailing role,and has a monotone rise parabola relationship with the material flow rate,and a top-protruding parabola relationship with the solid/gas ratio,which means it will increase before decrease.