Numerical Simulation And Experimental Research Of Cadmium Removal In ф75/ф100 Hydrocyclone

The cadmium removal hydrocyclone is a soild-liquid hydrocyclone. It separates the cadmium particles from the water by the centrifugal force which produced in the high-speed rotating fluid. The structure of solid-liquid hydrocyclone is quite simple, but the separate efficiency is very high and operation is very convenient, so it is widely applied in many industrial fields. The experimental research costs much and the cycle is long, so more and more researchers begin to use CFD technology to simulate the solid-liquid separate phenomenon in hydrocyclone.In this paper, a comparison study between two kinds of cadmium removal hydrocyclone was made. In order to study easily, firstly this paper uses the Reynolds stress model of the turbulence model to simulate the water flow in the two cadmium removal hydrocyclone of a factory, It is found that the flow of the fluid in the hydrocyclone is in a state of double spiral:in the center of the axi, the air column caused by the negative pressure will run through the bottom port to the overflow port;the tangential velocity of the flow field is the largest, the axial velocity is smaller, and the radial velocity is the smallest, and they are axisymmetrical; the pressure distribution of the flow field is axisymmetrical, the pressure near the wall surface is high,in the center it is low, in the regional of the air column it is lowest, and there is almost no change in the axial.Then a stochastic trajectory model of particle is simulated to the particle track in the two cadmium removal hydrocyclone, the trajectory of cadmium particle and flux, concentration and particle size on the separate efficiency changes are obtained. The research indicates:with the flux increased, the separate efficiency of the two hydrocyclones becomes higher, but when the flux increases to some certain extent, the separate efficiency will decrease; With the concentration increased, the separate efficiency will decrease obviously; The big cadmium particles are easier to be separated than the small cadmium particles, the classification efficiency will be close to 1 when the diameter of cadmium particles increases to some size, the cadmium particles bigger than that size almost can be separated; Compared with the two hydrocyclone, it finds that the separate efficiency will be better in the 75-mm hydrocyclone.Finally though the cadmium removal experimental research to the 75-mm hydrocyclone, the relationship between the entry flow and separate efficiency is obtained, the relative error is small between the numerical results and the experimental data, so it shows that the numerical simulation on the flow field and separate efficiency in this text is basically correct.