新型湿法除尘除有害气体斜板塔的流场分析

Analysis of flowfield in new types of towers with sloping plates for wet dedusting and hazardous gas removal

研究对象为2种新型湿法除尘除有害气体的斜板塔:矩形斜板塔和伞罩形斜板塔。为了观察塔内流场分布规律,运用CFD(计算流体力学)软件,气相采用标准κ-ε湍流模型描述,液相采用颗粒轨道模型描述,对2种新型塔内气液两相流动进行了数值模拟。预测了无喷淋和有喷淋两种情况下的气相湍流流场,不同空塔气速不同液气比的塔内压力损失。结果表明:采用中心出口的圆柱型塔可以有效地避免气体“死区”的产生;新型斜板塔能有效地增大气液接触面积,延长气体的塔内停留时间;加入喷淋液体以后,气相流场明显均匀化。该模拟也为塔体的进一步优化设计提供了依据。

The tower with rectangle sloping plates and the tower with umbrella sloping plates as two new types of towers for wet dedusting and hazardous gas removal were studied. In order to observe the distribution laws of the towers＇ flowfield, the gas-liquid two-phase flow in the two new types of towers was numerically simulated by using computational fluid dynamics （CFD） software, in which the gas flow and the motion of liquid droplets were respectively described with standard κ-ε turbulence model and particle trajectory method. It was predicted that the gas turbulence flowfield with/without spray, and the pressure loss of towers for two-phase flow. Simulation results showed that the dead areas could be effectively avoided in the cylinder towers with the central outlet, gas-liquid contact areas were effectively increased and the gas residence time was delayed,and the uniformity of gas flowfield was improved greatly when spray was introduced also. The study could provide foundation for optimizing the towers＇ design.