| Cyclone separator is widely used in petrochemical industry,gas purification and environmental protection because of its simple structure and convenient maintenance.improving the separation efficiency of separators is a research hotspot in this field.In the airflow movement of the separator,due to the rotation of the outer airflow,the outer pressure is greater than the inner pressure.Hence,the particles follow the airflow and enter the inner vortex area.In the inner vortex region,the tangential velocity decreases as the cylinder radius decreases.At the same time,the inertial centrifugal force also decreases.As a result,the probability of particles trapped in the inner vortex area will also be reduced.In order to prevent dust particles from entering the inner vortex zone,a new cyclone separator is proposed in this paper.Compared with the traditional separator,a group of swirl blades are arranged at the interface of vortex inside and outside the separator along the direction of airflow rotation.Based on CFD,the RSM model and the Discrete Random Walk model of discrete phase were used to simulate the gas-solid two-phase flow of the separator.The relationship between pressure drop,separation efficiency and inlet flow velocity of cyclone separator with conventional and cyclonic blades was studied experimentally.Finally,the effects of different exhaust pipe diameters and exhaust pipe insertion depths on the flow field and separation performance of the base separator and the added swirl vane separator are compared an d analyzed.The results showed that:(1)Under the exhaust pipe,a group of vortex blades are arranged at the interface of the inner and outer vortices along the rotation direction of the airflow to make the airflow flow around the blade.The particles in the airflow collide with the vortex blades,making it more difficult to enter the inner vortex zone,which is conducive to the efficiency improvement of the separator.(2)Compared with the basic separator,the flow field of the separator with cyclone blades is obviously optimized.The short cir cuit flow at the lower part of the exhaust pipe of the separator and the local eddy current at the ash outlet of the separator are obviously improved,which is conducive to the efficiency improvement of the separator.(3)The fractional efficiency of both the basic separator and the swirl vane separator increases with the increase of particle size.(4)The experimental results showed that compared with the basic separator,the total efficiency of the separator with cyclone blades is improved obviously when the inlet velocity is smaller.When the inlet velocity is large,the pressure drop of the separator increases slightly and the particle size of the separator decreases significantly.(5)When the inlet flow velocity is 13.94m/s,the fractional efficiency m easured by experiments is compared with the numerical simulation results.The fractional efficiency of the separator with cyclone blades is significantly improved,especially for particles with a particle size of less than 6μm.The numerical results show that the particle size of the basic separator is 2.07μm and that of the vane separator with cyclone is 1.47μm,which decreases by 29.0%.The experimental results show that the particle size of the basic separator is 2.33μm and the particle size of the vane separator with cyclone is 1.58μm,which decreases by 32.2%.(6)With the increase of the exhaust pipe diameter,the grading efficiency of separator decreases gradually.Compared with the basic separator,the classification efficiency of the cyclone blade separator with the same exhaust pipe diameter is higher,and the cyclone blade can effectively improve the classification efficiency of the separator.(7)With the increase of the exhaust pipe insertion depth,the separation efficiency of the separator is improved.Compared with the basic separator under the same conditions,the separation efficiency of the separator after the addition of the swirl blade is higher due to the difficulty of particles entering the inner vortex zone. |
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