Design And Test Of Control System For A Double-layer Tea Winnowing Machine

The wind selection process is necessary to affect tea values and the efficiency of the next operation.The wind selecting effect of the winnowing machine directly affects the value of tea,as well as the efficiency of the next operation.After the field visit in the tea factory,it was found that the existing single-layer winnowing machine in the tea factory was less efficient and usually required multiple re-selecting to improve the tea quality.Therefore,according to the requirements of wind selecting process,this project designs a PLC(Programmable Logic Controller)based double-layer winnowing machine control system and configures the best process parameters for different kinds of tea materials to improve the wind selecting efficiency.The main work of this paper is as follows.(1)To address the problem of repeated wind selecting in the traditional wind selecting process,a double-layer winnowing machine is designed,focusing on the design of the winnowing machine chamber,the end flake chamber,the feeding device and the tea divider in it.(2)In order to realize the automatic control of the double-layer winnowing machine,an automatic control system based on programmable logic controller is constructed,which realizes the speed frequency conversion of the double-layer fan and the automatic feeding process of the materials,which improves the intelligence and automation of the double-layer winnowing machine and optimizes the wind selecting results.(3)In order to adapt to the efficient wind selecting of a variety of tea materials,the AC motor control technology is used to establish an automatic regulation and control system for the position of the separating baffle,which can form a recipe library of different tea material parameters to adapt to the actual production needs of tea factories.(4)Two different tea materials are selected for testing on the winnowing machine.The three main factors affecting the effect of the winnowing machine are feeding speed,wind speed and the position of the tea divider.For the above three points to test,firstly,by changing the feeding speed and wind speed respectively to determine the optimal parameters,and then design a three-factor and three-level orthogonal test to find out the best parameters for the position of the tea divider,establish a database of process parameters,and finally find out that when the tea materials are basket tea raw materials,the feeder When the input voltage is 40%,the upper fan frequency is 30 Hz,the lower fan frequency is 35 Hz,the running time of No.3 tea divider is 5S,and the position of No.5 and No.6 plates remain unchanged,the double-layer winnowing machine achieves the optimal effect,and the main outlet contains 3.72% impurity rate.When the tea material is fried green tea,the input voltage of feeder is 30%,the upper fan frequency is 25 Hz,the lower fan frequency is 30 Hz,No.3 plate does not move,No.5 plate to the right to move 5s,No.6plate to the right to move 4.5s,winnowing machine can achieve the best effect of the main tea outlet containing 4.28%.The test results show that the double-layer winnowing machine has higher efficiency and better compared with the single-layer winnowing machine.