Study On The Law Of Heating And Mixing In The Device Of Spinning Disk Coupled With Microwave

For some viscous heating processes,such as biomass pyrolysis,hydrolysis and polymer devolatilization,the traditional kettle wall heating method has the problems of low heat utilization,uneven heating and limited mixing/surface renewal rate,resulting in poor product quality and low process efficiency.It is necessary to strengthen the heating and mixing process at the same time.The spinning disk reactor can strengthen the turbulence in the liquid film and then strengthen the mixing/surface renewal speed in the liquid phase,and the microwave has the characteristics of rapid bulk phase heating.Therefore,this topic proposes to carry out the experimental research on the heat supply and mixing law in the spinning disk coupled microwave device,study the influence law of various parameters in the coupling device on the heat supply effect and micro mixing effect,and then obtain its better operating parameters,so as to provide a basis for the application research of the coupling device.The main research contents are as follows:（1）Study on heat transfer law of viscous system strengthened by spinning disk coupled microwave.The effects of the relative position of microwave source,the number of microwave sources,rotational speed,viscosity and liquid volume flow rate on the temperature distribution and temperature rise rate of liquid on the disk surface were investigated.The results show that among the two groups of microwave sources parallel to each other,the microwave source installed vertically and parallel produces better temperature uniformity;The difference of temperature uniformity of several groups of microwave sources perpendicular to each other is small;When four microwave sources are turned on at the same time,the temperature uniformity is the best,but the temperature rise when the solution leaves the disk is low;When the vertically mounted single microwave source is turned on,the temperature rise of the solution is the largest and the temperature uniformity is good;The increase of viscosity will reduce the uniformity of temperature;Increasing the speed and flow rate will help to improve the uniformity of temperature.At 600 r·min^-1,the COV value decreases to 0.006,and the temperature uniformity is improved by90%compared with 200 r·min^-1;Compared with conventional microwave heating,it is found that the spinning disk coupled microwave not only speeds up the heating rate,but also improves the temperature uniformity.（2）Study on micro mixing performance of spinning disk coupled microwave reactor.The effects of rotational speed,microwave power,H⁺concentration and liquid volume flow rate on the segregation index were investigated.The results show that high speed and high flow can reduce the segregation index;The increase of H⁺concentration will increase the segregation index;With the increase of microwave power,the segregation index first increases and then decreases,and the segregation index decreases at high speed and high power.And the separation index is 0.027 under better conditions.And combined with the experimental results of heat supply law,it is found that the mixing effect in the coupling field is consistent with the variation law of heat supply uniformity.