Abstract

The objective of the present research is to evaluate the effect of changing the length of the cylinder and cone such that the total cyclone length remains unaltered. For this purpose, five different cyclone models with increasing lengths of cylindrical section (H_c/D = 0.5, 1.0, 1.5, 2.0, and 2.5) have been considered. A comparison is made among different flow variables as well as the performance parameters. Unlike general engineering flows, cyclonic flows possess strong swirl, resulting in high streamlined curvatures and rapid change in strains that makes it anisotropic in nature. Therefore, we use the Reynolds stress model (RSM)—a closure model to Reynolds-averaged Navier-Stokes equation—to account for such anisotropies in the flow. The Navier-Stokes equations are discretized using finite volume methods and solved using commercial code Fluent. Conclusive results indicate that the collection efficiency, pressure drop, and tangential velocity are maximum for cyclone with H_c/D = 0.5 and minimum for H_c/D = 2.5. It has also been observed that at higher inlet velocities heavier dust particles accumulate near the cyclone roof, which may result in high rates of wall erosion.

摘要

本研究的目的是评估改变圆柱体和圆锥体的长度以使总旋风分离器长度保持不变的效果。为此，五种不同的旋风​​分离器模型随着圆柱截面长度的增加（H _c / D = 0.5、1.0、1.5、2.0 和 2.5）已被考虑。在不同的流量变量以及性能参数之间进行比较。与一般工程流动不同，气旋流动具有强烈的涡流，导致高流线曲率和应变的快速变化，使其在性质上具有各向异性。因此，我们使用雷诺应力模型 (RSM)（雷诺平均 Navier-Stokes 方程的闭合模型）来解释流动中的这种各向异性。Navier-Stokes 方程使用有限体积方法离散化，并使用商业代码 Fluent 求解。结论性结果表明， H _c / D  = 0.5的旋风分离器的收集效率、压降和切向速度最大，而H _{c的收集效率、压降和切向速度最小。}/ D  = 2.5。还观察到，在较高的入口速度下，较重的尘埃颗粒会在旋风顶部附近积聚，这可能会导致高速率的壁腐蚀。