Design And Experiment Of Corn Dryer With Counter Current

Mechanized drying has been popularized,but there are still some defects in the use of drying tower for drying operation.The most typical problem is that the moisture content of machine grain cannot be accurately controlled.Each drying operation depends on experience to set some drying parameters such as air temperature and drying time.The main reason for this problem is that the online moisture testing equipment is very expensive,and because of the large size of the drying tower,it is very inconvenient to measure the instant drying parameters in the drying operation.To solve this key problem,this paper designs and manufactures a parallel and counter current corn dryer by referring to the internal structure of large-scale drying tower and the ratio of slow to solvent.The production capacity of the dryer is required to be 8 t/%?h.The specific research contents and conclusions are as follows:(1)Solid Works software is used to carry out three-dimensional design of each part of the dryer and complete the overall assembly work,and the simulation module is used to carry out numerical analysis of the key parts of the dryer.The results show that:the stress in the middle of the angular box is relatively concentrated,and the maximum stress is 7.07×10~7N/m~2(the yield strength of Q235-B is 2.35×10~8N/m~2);the surface temperature cloud of the angular box has no obvious change,and the heat transfer effect is good;the stress in the middle of the discharge wheel is relatively concentrated,and the maximum load is 2.72×10~7N/m~2,and the maximum torque is 5.44×10~6N?m;(2)The flow module is used to analyze the corn fluid.The results show that:when the initial velocity of corn is 1m/s,the falling velocity of corn is parabolic with the displacement of corn;when the displacement of corn reaches 110mm,the velocity of corn reaches the maximum value,about 1.85m/s,and then begins to drop to 1m/s;when the medium density is1200kg/m~3,the turbulence intensity of corn is M-shaped;when the distance between corn and the edge of angular box is 300mm and 900mm,the turbulence intensity of corn is M-shaped The results show that the temperature of the fluid subdomain in the angular box is set at50℃(323k),and there is no obvious change at 325k.(3)The effect of pre temperature on the quality of corn was similar to that of th e laboratory.The evaluation indexes of corn quality were electrical conductivity,starch yield and fatty acid value.The results showed that the electrical conductivity,starch yield and fatty acid value of corn changed significantly when the grain temperature ex ceeded 50℃,so the grain temperature should be≤50℃.(4)Under the condition of grain temperature≤50℃,the drying capacity,precipitation range and production capacity of the dryer were verified.The results showed that the drying unevenness of corn grain was less than 1%,the precipitation range of corn grain was 4.55%,the increasing value of crushing rate was 0.3%,the increasing value of crack rate was 5.2%,and the processing capacity per unit time was 1.8t/h.The production capacity of the dryer was8.29t/%?h(>8t/%?h)The production capacity of the dryer meets the design requirements.