Research On Hot Air Drying Characteristics Of Salt Mud And Drying Effect Of Multi-layer Drying Chamber

In the process of salt mud harmless recycling,it is necessary to dry the salt mud particles with a moisture content of about 30%.In view of the problems of low drying efficiency and uneven moisture content after drying of salt mud particles in the process of hot air drying,the hot air drying characteristics of salt mud particles and the drying effect of salt mud in a multi-layer drying chamber were investigated by a combination of ex-perimental research and numerical simulation.Research and analyze the changing law of water content and water content in the drying process of salt mud particles.The main work of this paper is as follows:（1）The relationship between the hot air temperature,wind speed and stacking thickness and the drying rate of the salt mud was obtained through the hot air drying experiment of the thin layer of salt mud particles.Com-paring these laws with several theoretical models,it is shown that:the Mi-dillli model is the best model to describe the hot air drying characteristics of salt mud particles;the hot air drying process of salt mud particles has been in a state of decelerating drying;The key factor of the process is that when the temperature increases from 50℃to 80℃,the effective water dif-fusion coefficient of salt mud particles increases from 2.04×10^-9 to 8.14×10^-98)²/.（2）Based on the theory of heat and mass transfer in porous media and the principle of local non-thermal equilibrium,the above thin-layer drying model and related physical parameters are used to establish a simulation model of moisture and heat transfer in the multi-layer hot air drying process of salt mud in a multi-layer drying box.Through numerical simulation and experimental verification,it is shown that the above moisture and heat transfer model is very suitable for the simulation of the multi-layer hot air drying process of salt mud.The simulated data of particle moisture content and temperature are in good agreement with the experimental data.（3）The drying effect of salt mud particles in the multi-layer drying chamber was studied by using the above-mentioned salt mud multi-layer moisture heat transfer model.After the multi-layer drying chamber is im-proved by the arc transition and the addition of staggered distribution plates,the drying effect is significantly improved,the non-uniformity of moisture content after drying is reduced by 5.4%,and the drying rate is increased by4.6%.The results of the thesis can be used as a reference for the drying pro-cess of salt mud particles and the design of the drying chamber structure.This article has 38 pictures,13 tables,75 references.