加压粉煤气力输送试验研究

Experimental study of dense-phase pneumatic conveying of pulverized coal at elevated pressures

通过建立加压粉体气力输送试验系统并进行加压粉煤气力输送试验,重点考察了表征气速、输送背压和粉体流量对管道压损的影响。结果表明:不同输送背压和粉煤流量下,粉煤加速压降、垂直到水平弯管、水平到垂直弯管和水平弯管压损与粉体流量Gs和表征气速Ug的乘积呈近似线性关系,其中水平到垂直弯管压损随GsUg变化最大;水平、垂直和倾斜管段附加压损随着表征气速的增加而逐渐减小,粉煤流量比输送背压对附加压损影响更大;附合压损系数是Re、Fr和气固比μ的函数,通过拟合得到的附加压损公式和总压损公式的预测值也与试验值吻合均良好。

The pressure losses along the pipeline during pneumatic conveying of pulverized coal at elevated pressures were studied experimentally for various superficial velocities,Ug,conveying back pressures and mass solid flow rates,Gs.The results showed that the pressure losses due to acceleration and in vertical-to-horizontal bends,horizontal-to-vertical bends and horizontal bends in the pipeline increased approximately linearly with the product of the superficial velocity and the mass solid flow rate,GsUg,with the pressure loss in the horizontal-to-vertical bends being most sensitive to GsUg.The additional pressure losses in horizontal,vertical and inclined pipes gradually decreased to zero with increasing superficial velocity.The mass solid flow rate had a greater impact on the additional pressure loss than the conveying back pressure.The coefficient of additional pressure loss was a function of Re,Fr and the solid-gas ratio μ.Predictions of empirical correlations for the additional pressure loss and the total pipeline pressure loss both agreed well with the experimental data.