Investigation on particulate matter and gas motion processes in the advanced multi-channel cyclone-separator with secondary gas inlets

Abstract

Research into gas flow motion as a transported phase and pollutant – particulate matter (PM) is of crucial importance, their changes in particular areas of the object require knowledge of improving the apparatus. A cyclone is considered one of the most popular devices due to the new modified multi-channel design that involves combined separation and filtration phenomena. The findings of an accurate numerical model provide an opportunity to verify long-term experimental studies. In addition, it is possible to determine the impact of the designed principal elements of the structure comprising secondary gas inlets, inner slits and the convex bottom on gas and PM motion through verification conducting experimental research. The study focuses on simulating the upgraded cyclone using the SST k-omega model. The research has been conducted under the specified gas flow conditions such as high temperature and relative humidity (aggressive) gas and presents the results of the physical model to compare with. To achieve greater computational accuracy, a digital model of the cyclone made of specific volumetric elements has been developed thus expanding the grid and stepping to form the boundary zone. As a result, numerical simulation results differ by no more than 12.8% compared to the experimental studies results.

Experimental investigation of a one-level eight-channel cyclone-separator incorporating quarter-rings

“…Results in that study obtained based on the numerical modeling predicted the effectiveness of trapping PM10 of 72 %, which was on average 1.7-fold higher than that predicted for PM2.5 amounting to 41.3 %. These results were confirmed, experimentally, reaching average trapping efficiencies of 46.9 and 78 % for particulate matter of 2.5 μm and 10 μm in diameter, respectively [34].…”

“…That air flowrate is often used in boilers (solid fuel (coal, coke, wood pellets used for heat or hot water production). Cyclone-separator is installed behind the boiler for separation of particulate matter from the emitted flow of a boiler of average power (0.5 -1 MW) while the gas velocity corresponds to the range from 10 to 20 m s -1 usually used in conventional cyclone-separators [33,34]. For example, at the gas flowrate of 113 m -3 h corresponding to the velocity of 16 m s -1 , the cyclone pressure drop was measured as 1200 Pa [35].…”

“…The summarized tests data show that the aerodynamic resistance in this case was 1150 Pa. A study of the aerodynamic resistance of a four-channel cyclone [37] demonstrated that an aggressive dispersed gas and vapor flow increased the pressure drop by approximately 10%. Based on a numerical simulation study [34], the highest static pressure zones are at the beginning of the first and second channels where pressure values reach around 350 Pa. The static pressure of gas flow has been experimentally proved to reach 640 Pa prior to entering the cyclone but decreases by 50 % in the next sections [34].…”

“…Based on a numerical simulation study [34], the highest static pressure zones are at the beginning of the first and second channels where pressure values reach around 350 Pa. The static pressure of gas flow has been experimentally proved to reach 640 Pa prior to entering the cyclone but decreases by 50 % in the next sections [34]. Due to a more complex internal design of the multi-channel cyclone-separator as compared to a hollow conventional cyclone, the pressure drop is for 10-15 % greater at low flowrates, while it is equal in both devices at the maximum inlet flowrate [38].…”

CFD Simulation of an Industrial Dust Cyclone Separator: A Comparison with Empirical Models: The Influence of the Inlet Velocity and the Particle Size on Performance Factors in Situation of High Concentration of Particles

“…Many attempts have been conducted to improve the separation performance of cyclone separators by optimizing the structure dimension, such as vortex length [14,15], vortex fnder shape and diameter [16][17][18], inlet type, including single, double inlet and more than two inlets [19][20][21], tangential, and spiral inlet [20], inlet dimension [22], diferent inlet section angles in relation to the cyclone body [23][24][25], symmetrical inlet and a volute scroll outlet [26], cone tip diameter [27,28], cyclone height [29], conical length [18,30,31], diameter and length of vortex fnder [32,33] and hopper length [9]. Tere are also various kinds of cyclone separators developed to improve the separation efciency, such as Lee type [34], semispherical cyclone [35], dynamic cyclone [36], square cyclone [37], CFC cyclone [38], and the new generation of cyclone separators presented as multichannel cyclone separators [39][40][41][42][43]. Te multichannel cyclone separator's structure has some essential external and internal elements, including upgraded curved elements with openings cut with their plates bent outwards to make curvilinear channels for the continuous movement of the peripheral and transitional gas fows from the infow opening to the central axis [39].…”