Flow Simulation and Performance Comparison of Rough‐Cut Cyclones with Different Structures in Dilute Phase

Abstract

The gas‐solid flow behavior and dust distribution in four rough‐cut cyclones was numerically simulated on the platform of FLUENT 6.2. The Reynolds stress model and stochastic particle tracking model were used to describe the gas flow and particle motion. The calculation results indicated that the particle distribution patterns of the four rough‐cut cyclones were similar. Adding solid particles into the gas phase weakened the gas swirling intensity inside the cyclones. Data of rough‐cut cyclone down‐flow ratios were gained by simulation for the first time. Rough‐cut cyclones with wider diplegs were found to have a massive gas down‐flow through the dipleg which might cause serious coke generation inside the disengager. The simulated cyclone structure with its vortex finder wider than the dipleg and a hopper installed behaved the best. The results may provide indications for industrial anti coke research and rough‐cut cyclone design.

CFD Modeling of Gas–Solid Cyclone Separators at Ambient and Elevated Temperatures

“…One of the important features that is captured by two-and four-way coupled CFD simulations of cyclones is the modulation of velocity field and turbulence statistics as compared to the particle-free flow. The swirl velocity is predicted to reduce substantially with the addition of particles to the flow and decrease further as the loading of particles increases [35,102,106,109,116]. The predicted reduction of tangential velocity magnitude as well as turbulent fluctuations by the addition of 0.05 and 0.1 kg s /kg g of particles to a pilot-scale cyclone is shown in Figure 6 based on the LES study of Derksen et al [116].…”

“…As for the third category of CFD studies, category (III), compared to the previous categories, there are fewer E-L studies with two-way coupling [34,77,[98][99][100][101][102][103][104][105] and only a limited number of studies with four-way coupling [35,[106][107][108][109]. In almost all of the studies (except [99]), due to the lack of available experimental data for the cyclone flow loaded with particles, no comparison of the predicted modification of velocity profiles (compared to the single-phase flow) with the measurements is provided.…”

“…In almost all of the studies (except [99]), due to the lack of available experimental data for the cyclone flow loaded with particles, no comparison of the predicted modification of velocity profiles (compared to the single-phase flow) with the measurements is provided. Instead, the predicted overall/grade efficiencies [34,77,101,102] and/or pressure drops [34,35,98,101,102,106,107,109] are compared with the measurements for certain ranges of particle mass loading. A summary of the existing four-way coupled CFD studies of gas-solid cyclones operating at ambient temperature and with inlet mass loading ratios higher than 0.1 kg s /kg g is presented in Table 2.…”