Influence of a laminarizer at the inlet on the classification performance of a cyclone separator

Effect of a new pattern of surface roughness on flow field and erosion rate of a cyclone

This paper evaluates the impact of a special design of non-uniform surface roughness on the operating parameters of a gas–solid cyclone numerically. The cyclone surface is divided into 32 separate rings with different roughness heights when the roughness height varies from 0.2 to 3 mm. The results show that the tangential velocity is reduced and the axial velocity is enhanced by increasing the height of non-uniform roughness. It is observed that the cyclone with smooth walls can collect 7 μm solid particles while 3.7 and 2.77 μm particles can be separated by one-inlet and two-inlet cyclones, respectively. For the cut-off size diameter of d 50, the one-inlet cyclone with smooth walls can collect the particles with a diameter of 1.24 µm, while the cyclone with R Nu = 0.2, 0.5, 1, 2, and 3 mm can collect 1.3, 1.6, 1.8, 0.83, and 1.88 µm particles, respectively. The results demonstrate that the erosion rate decreases with the roughness and this reduction is larger for the one-inlet cyclone.

Experimental Investigation of the Effects of Helical Roof on the Performance of Stairmand High Efficiency Cyclone

Cost-effectiveness of a standard and a modified Stairmand high-efficiency type cyclone was compared at various inlet gas velocities. The modified design was obtained by replacing the roof of the standard design with a helical roof. Experiments were conducted by both standard and helical roof designs at the same operating conditions. Results showed that helical roof leads to reduced pressure drop in cyclones while having a negative impact on particle collection efficiency. Reductions in pressure drop can reach up to 30%, while particle collection efficiency is reduced by up to 8% simultaneously. Overall, the treatment cost of a cyclone separator can be reduced by 14.1–20.8%. Results indicated that helical roof design cyclones can be used to reduce overall treatment cost by cyclone separators.

Dust Suppression Analysis of a New Spiral Hopper Using CFD-DEM Simulations and Experiments

A new dust suppression hopper with a spiral guide plate embedded in the conventional hopper is proposed for the dust suppression of hopper transfer processes in this article. The Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) coupling numerical method is used to investigate the particle motion and flow field distribution of the hopper transfer process. The experiment is undertaken to determine dust suppression performance. The results show that the maximum particle velocity for the spiral hopper is dropped by 1.6 m/s compared to the conventional hopper, which means the collision of the particles and the spiral hopper is weakened. The axial airflow velocity of the spiral is reduced. In addition, the maximum dust concentration of the spiral hopper inlet is reduced by 56.9% due to the impact velocity of particles is small, and the secondary fugitive dust is controlled inside a semi-closed space formed by the spiral guide plate. It is thus concluded that the spiral hopper provides an effective way in dust control.