高压浓相粉煤气力输送

Dense-phase pneumatic conveying of pulverized coal under high pressure

在高达700kg/m3的高压气力输送试验台上,用氮气进行煤粉高压浓相粉煤气力输送试验研究.分别在不同的总输送差压、煤粉含水率、风量和压力等条件下进行了输送试验,考察操作参数对煤粉质量流量、固气比和单位管道长度的压损等气力输送特征参数的影响.结果表明:随着总差压和流化风流量的增加,煤粉的质量流量增大;当流化风流量较小时,煤粉质量流量受流化风的影响较大,随着流化风流量增大,流化风对煤粉质量流量的影响变缓.固气比随着注入速度的增大先增大后减小,随着总差压的增加而增大;其他输送参数相同的条件下,输送压力越高,煤粉的质量流量和固气比就越大;随着含水率的增加,煤粉的质量流量逐渐减小;在输送相图中,相同煤粉湿度下,输送压损随表观速度的增加先减小后略有升高;相同表观速度下,煤粉含水率越低,压力损失越大.

Experiments of pulverized coal dense-phase pneumatic conveying using nitrogen were carded out in an experimental setup. The influences of total conveying differential pressure, pulverized coal moisture content, injected velocity and pressure on the characteristic parameters were investigated. The results indicate that the pulverized coal mass flow rate rises with increase in total conveying differential pressure or fluidizing gas volume rate. The effect of fluidizing gas on mass flow rate is greater when the fluidizing gas volume rate is less, but it slows down as the fluidizing gas becomes bigger. The solid-gas ratio rises with increase in total conveying differential pressure and increases at first and then declines as injected velocity increases. The higher the total conveying pressures are, the higher the mass flow rate and solid-gas ratio are under the same experimental condition. Mass flow rate decreases with enhancing pulverized coal moisture content. The differential pressure per unit length of horizontal pipeline decreases first and then appreciably rises with decrease in apparent velocity. The lower the pulverized coal moisture content is, the more the pressure drop is under the same apparent velocity.