Design And Simulation Of Mechanical Stirring Horizontal Spray Drying Process

This study designed a horizontal spray drying progress with mechanical stirring and water vapor internal circulation to conquer the shortage of the traditional treatment of high-salt wastewater,and according to the progress model,it was made a simulation of the details of spray drying and crystallization,in the light of which a correction was given to the model.And according to the modified data,the physical device was made to testify the feasibility of the process.Firstly,an introduction of different parts of the progress that should be calculated and made clear was given.Then,the moving conditions in the horizontal and vertical direction of the droplets was analyzed to make sure how long it would need for the drying progress which gave a basis for the size of the main drying part.And according to the size we got above,the corresponding auxiliary process section could be matched to complete other requirements for the progress.After that,a heat transfer calculation for all related parts was made to determine the power demanded and get the initial geometry.Using the data from the simulation above,the physical device was made,and the according experiment was done which showed that a part of the treated high salt water was turned to crystal proving that the process mentioned above was feasible.Secondly,in line with geometric model and the different physics filed coupling situation the required simulation tools and simulation process was decided,that was using the Solideworks for the construction of geometry,meshing for the grid division,fluent for the calculation of flow field.Then,adjust the parameters in the calculation to make sure it have a convergence result and can be repeated.Thirdly,it was made an exploration for the different factors' influence on the field's situation.The discussion of the moving condition of the vapor phase was the first,taking the change of inlet speed of vapor phase and stirring speed into account,which showed that the appropriate range for the speed of inlet vapor is10-15 m·s-1,and the stirring speed is 100-150 rpm.Then it was the turn of the movements of the droplets,which was affected by its feed amount and the stirring speed.And it showed that 0.29 kg·h-1and 75-125 rpm should be a recommended result.After that,the temperature of the dispensed phase(concluding the droplets and solids)was studied under the change of the temperature of vapor inlet?the feed amount of the droplets and the speed of stirring,giving us a result that parameters should be 10 m·s-1?1.45 kg·h-1,150 rpm.Afterwards,it came to the judgement the crystalline ratio which had two factors(feed amount of droplets and stirring speed)to influence.It showed that when the stirring speed is above 125 rpm,the droplets could get a drying ratio about 100%when its feed amount was below 1.16 kg·h-1,which declined to 90%when the feed amount is between 1.16-1.45 kg-h-1.Finally,the range of 75-125 rpm and 250-500 rpm was selected and the 75-125 rpm range was finally selected.