Numerical Simulation And Structural Optimization Design Of Flow Field In Solid-liquid Separation Of Ceramic Membrane

Ceramic membrane solid-liquid separation device is widely used in the solid-liquid separation process of "rare,complex and fine" ore pulp.However,ceramic membrane holes are easy to clog in the process,resulting in production efficiency reduction,production cost increase and other shortcomings,which is a practical problem faced in engineering applications.Therefore,a set of ceramic membrane solid-liquid separation test equipment was built in this paper.The flow field characteristics of ceramic membrane solid-liquid separation process were studied.Combined with experimental and numerical simulation methods,the influencing factors and mechanism of membrane hole plugging were analyzed,and the optimal design scheme of ceramic membrane plate structure was proposed.The main research work of this paper is as follows:1? The design and construction of solid-liquid separation device for ceramic membrane in this paper refer to relevant industry standards,and the operation of the device is controlled online by PLC system.This device can independently complete the process of vacuuming,solid-liquid separation,filter cake unloading and membrane cleaning.Through the filtration experiment in pure water state,the device is reasonable in design and good in tightness.2? Establishment of solid-liquid separation device for ceramic membrane.According to relevant industry standards,a set of ceramic membrane solid-liquid separation test equipment was designed and built according to the 1:1 size of ceramic membrane plate,which can realize the continuous operation and control of slurry homogenization,vacuum pumping,solid-liquid separation,filter cake unloading,membrane back blowing cleaning and other processes.The device adopts PLC system and Kingview software for online control,which can realize the acquisition of vacuum degree,flow rate,filter cake thickness and other parameters to meet the requirements of experimental research.3? Numerical simulation of solid particle interception and capture and reverse blow desorption behavior.Based on Fluent and DEM methods,a single straight hole physical model was established to simulate the interception,capture and reverse blowout desorpation behavior of solid particles in the solid-liquid separation process of ceramic membrane plate.The Newton force model and Navier-Stokes equation were used to solve the problem.The results show that the model is reasonable.During the solid-liquid separation process of ceramic membrane plate,solid particles are affected by the liquid bridge force,which makes it easy to bond between particles and between particles and between particles and wall surface,leading to the blockage of solid particles in the middle of the membrane hole channel.The pore blockage of ceramic membrane can be effectively reduced by increasing the solid content of slurry and particle size.The gas pressure is the key factor to clear the particle blockage in the channel of membrane hole,but the influence of extending the back blowing time on the process is relatively low.4? Analysis of gas flow characteristics in ceramic membrane during backblow cleaning.On the size of the ceramic membrane to carry on the physical modeling,model calculated by using Fluent software multiphase ceramic membrane in the process of back plate internal gas-liquid two phase flow characteristics are numerically simulated,results show that the calculated value is close to the experimental values,the institute adopts the calculation model is reasonable,airflow movement are greatly influenced by ceramic membrane internal shores,cause gas blow,The loss of gas pressure and flow rate is large,and the airflow transferred to the bottom of ceramic membrane plate is less,resulting in the decrease of ceramic membrane back blowing cleaning efficiency.5? Optimization design of internal structure of ceramic membrane plate.Based on the Fluent multiphase calculation model,the internal structure of the ceramic membrane plate was optimized.The results show that reducing the diameter and number of the support column can effectively extend the transmission distance of the airflow and improve the back blowing area.In the optimization design of the air intake mode,replacing the two-hole air intake with the surface air intake can effectively prevent the airflow vortex inside the ceramic membrane,increase the air back blowing action surface,and improve the airflow back blowing through speed.