An innovative industrial device named the Square Cyclone Separator with Laminarizer was developed to improve the effectiveness of particle separation in gas streams. Unlike conventional cylindrical cyclone separators, this novel separator has a square-shaped body that offers a compact and space-efficient design. A crucial improvement is the incorporation of a laminarizer at the entrance stream, which guarantees a more consistent flow distribution and lowers turbulence. To simulate such intriguing device, a reference paper entitled “ Improving efficiency of conventional and square cyclones using different configurations of the laminarizer [1]” is selected that lead us through adopting proper assumptions.

• Reference [1]: Fatahian, Hossein, Esmaeel Fatahian, and Majid Eshagh Nimvari. “Improving efficiency of conventional and square cyclones using different configurations of the laminarizer.” Powder technology339 (2018): 232-243.

Figure 1: The geometry of conventional cyclone with laminarizer [1]

Simulation Process

The vortex finder laminarizer has seven hollow tubes positioned vertically at the end part of the vortex finder, whereas the inlet laminarizer has 3 × 5 hollow tubes arranged horizontally at the entry portion. This model is created using Design modeler. Then, the domain discretized into 2540574 tetrahedron cells. The problem has two phases: a continuous phase (air) that carry the discrete phase (particles) from the inlet and laminarizers through the outlet. Hence, the Discrete Phase Model (DPM) is needed to track the particles. The particles` size is in the order of micron, it mean they cannot make remarkable effect on the other phase. Therefore, assuming a 1-way DPM module is fairly acceptable. Notably, the dispersion model is discrete-random-walk, leading to more realistic injection.

Figure 2: The geometry of laminarizers – square cyclone [1]

Post-processing

The particle tracking image shows that the square cyclone separator works well at getting rid of particles because most of them stay inside for only 0.5 seconds. By examining the colored path lines, it is easy to see how the particles enter through the inlet and instantly form a tight spiral pattern as they move downward. What’s interesting is how much better the laminarizer makes the flow behave; those 3×5 hollow tubes at the entrance order the flow so that it flows in organized streams that follow predictable paths. It’s not just better looking; it also makes things work better. Only a few particles make it to the yellow-red zones (0.384-0.640 seconds), but most of the particles move in the blue-to-green range (0.064-0.320 seconds). With such a quick journey, there is less pressure drop and still a high rate of separation.

Figure 3: Injected particles residence time & velocity inside the square cyclone separator

The velocity contours show that the speeds range from almost nothing at the walls to 18.15 m/s at their fastest in the center vortex region. In contrast to cylindrical forms, the square shape makes corner flow patterns that are more effective at separating particles. The ANSYS Fluent simulation with DPM modeling shows how the secondary laminarizer (seven hollow tubes at the vortex finder) keeps particles from going straight to the exit and short-circuiting. The particles take a longer circular path, which gives centrifugal forces more time to push them outward. The square form also makes the pressure field more stable throughout the separator body, which lowers the turbulent eddies that happen in regular cyclones and bring particles back together. In industrial gas cleaning uses, this new design shows that sometimes going against the usual cylindrical cyclone shape can lead to big performance gains.