Research On Structure Optimization And Flow Field Simulation Of Heavy Medium Cyclone

Coal preparation technology plays a key role in the efficient use of coal resources in China.By 2020,the rate of raw coal washing will increase to over 80%.Among the many coal preparation methods,the application of heavy medium coal preparation is the most widely,the sorting principle is simple,the separation efficiency is higher than other separation equipment,the space occupied by the equipment is small,and continuous operation can be realized,which is more and more recognized by the market.The traditional heavy medium cyclone technology as the core equipment has made rapid progress in recent years in terms of large-scale,but there are still some problems in the sorting of materials from the structural design for its own sake:There is a continuously oscillating air column inside the cyclone when the cyclone works,which affects the sorting precision and consumes a large amount of energy;when the cyclone is running,the zero-speed envelope surface is very unstable due to the existence of spiral flow along the axial and internal directions.As a result,the accumulation of particulate materials near the zero-speed envelope surface causes the phenomenon of particle retention fluctuations,which seriously affects the sorting accuracy of the product.In the existing cyclone technology,the distributed flow field has eccentricity,which increases the energy to some extent and reduces the sorting accuracy.The working principle of the traditional cyclone determines the inevitable existence of these technical problems,which fundamentally limits the development of the traditional heavy medium cyclone technology to low energy consumption and high efficiency.The development of the existing cyclone is almost in a state of stagnation,so a breakthrough new cyclone is imperative.Through FLUENT numerical simulation,the phenomenon of fluid flow in the flow process can be clearly displayed,and the optimal design parameters of the process can be obtained by changing various parameters in the simulation process.By calculating the numerical simulation,we can more intuitively understand the influence of the setting of various parameters on the simulation results,so it can provide guidance for the later experimental finishing and regular discovery,saving the time and material power required for previous experiments.This paper starts with the separation theory of the traditional cyclone,and overcomes the instability of the internal flow field of the traditional cyclone and the energy loss of the internal air column,which breaks through the traditional theory of rotational flow separation and explores the structural innovation heavy medium cyclone.Due to the high precision,low energy consumption and stable flow field structure,the sorting accuracy of the cyclone has improved and energy consumption has deduced.Through laboratory experiments,the conclusions of numerical simulation were verified.Due to the reduction of turbulent mixing in the new cyclone,the separation accuracy was improved.The possible deviation E_P value obtained by sorting fine coal(-2mm)was 0.04;The sorting density in the heavy medium cyclone can be directly monitored because it is equal to the density of the medium in the overflow;since the density of the feed medium is much higher than the sorting density,the stability problem of the medium can be alleviated or eliminated;and due to the unique overflow tube design,the turbulence phenomenon of the material inside the cyclone is greatly reduced.