粉煤在流化料仓中的下料特性

Flow characteristics of pulverized coal from aeration silo

在自行设计的有机玻璃流化料仓系统上对粉煤下料过程及其特性进行了实验研究。研究发现,在筒仓段与料斗段连接处上方存在一个临界面。在临界面以上的筒仓段,粉煤以柱塞流形式下料,在临界面以下,粉煤以不定向螺旋运动下料。研究结果表明,料斗下部的流化气对下料稳定性和下料流率有重要影响,存在最佳流化气位置区间和最佳流化气表观气速范围,当流化气补气位置太低,在补气位置附近易形成气压平衡拱。研究还表明,增加料仓压力能提高粉煤下料流率,改善下料稳定性,减弱流化气补气位置及气速对下料的影响,阻止气压平衡拱生成。

The flow characteristics of pulverized coal from a glass aeration silo was investigated. There existed a critical surface above the joint of bin and hopper during discharging. Plug flow was discovered above the critical surface in the experimental research, while pulverized coal flowed spirally under the critical surface randomly. The results showed that aeration gas had a great effect on mass flow rate and flow stability. There existed an appropriate location of aeration gas supply and superficial velocity. Gas pressure balance arching would form easily when the aeration gas supply was too low. Flow rate could be increased and flow stability could be improved by increasing silo pressure. Also increasing silo pressure could decrease the effect of the location of aeration gas supply and superficial velocity on flow rate and stability and could prevent the formation of gas pressure balance arching.