模拟含硼废液喷雾干燥试验

SPRAY DRYING TEST OF SIMULATED BORATED WASTE SOLUTIONS

研究了三种喷雾干燥方式处理模拟含硼废液试验的性能和影响因素。三种喷雾干燥方式为:旋转式雾化并流喷雾干燥、气流式雾化并流喷雾干燥和气流式雾化混合流动喷雾干燥。对于硼浓度21000ppm(10-6)的模拟含硼废液,在供料温度为62～64℃,干燥塔进出口温度分别为210～220℃和110～120℃,压空流量为8.0m3/h,雾化器转速为73.0m/s的条件下,三种喷雾干燥方式均得到了流动性良好的粉体,粉体中占总质量95%的粉体粒径在0.356～0.061mm之间。三种喷雾干燥方式处理模拟含硼废液的减容系数在0.22～0.27之间,气流式雾化并流喷雾干燥方式、气流式雾化混合流动喷雾干燥方式和旋转式雾化并流喷雾干燥方式的废液处理能力依次增大,所得粉体的含水率依次增大。

Performance and the effecting factors of spray drying of simulated borated waste solutions is studied for three contaeting methods between the atomized beads and the heated air, in which boron concentration is arround 21000 ppm. The contacting modes are centrifugal atomizing co-current flow, pneumatic atomizing co-current flow and mixed flow. The results show that a free-flowing product in all these tests when the temperature of the solutions is between 62 ℃ and 64 ℃, the inlet temperature of the spray drying chamber is between 210 ℃ and 220 ℃, the temperature of the outlet of the spray drying chamber is between 110 and 120 ℃, the flow rate of the pressure air is 8.0 m^3/h, the rotational speed of the centrifugal atomizer is 73.0 m/s. The diameters of the powder product which account for 95% of the feed range from 0. 356 mm to 0. 061 mm. The production capacity and water content in the powder increase in the order of pneumatic atomizing co-current flow, mixed flow and centrifugal atomizing co-current flow. The volume reduction coeffecient of spray drying is in the ranged of 0. 22 and 0. 27.