Optimal Design And Test Of Cotton-picking And Discharging System

Cotton is one of the most important crops in China,and its annual output has been ranked first in the world for many years.The sharp increase of output and the sharp decrease of labor force make the rapid development of cotton mechanized harvesting in China,but also bring some problems.Mechanized picking of cotton(machine picking cotton)is not like manual picking of cotton(hand picking cotton)when the immature peach,cotton stalk,cotton leaf,three silk,chemical impurities and other substances are selected out,so there are problems of high impurities and high moisture content in machine picking cotton,which brings great difficulty to the subsequent cleaning and processing of machine picking cotton.Therefore,based on the existing machine picking cotton cleaning processing technology,equipment,process and other aspects,this paper designs a kind of machine picking cotton cleaning and impurity removal automatic device,carries out the feasibility analysis,theoretical analysis,gas-solid two-phase flow analysis and heat source analysis through simulation,and makes a small self-propelled machine picking cotton conveying device test platform,which has the advantages of time saving,energy saving and impurity removal Experimental analysis was carried out.The specific research contents are as follows:(1)Through the investigation in the southern area of Xinjiang,it is found that the material conveying mode of constant time and speed is generally adopted in the process of cleaning and removing impurity of machine-picked cotton.By adding an energy-saving control system to the machine-picked cotton impurity removal conveying device,and optimizing it to meet the local characteristics,it can effectively solve the problems of large energy consumption,short life,long working time and slow impurity removal efficiency of the device.(2)The material characteristics of machine-picked cotton were measured and analyzed.The measurement results show that the impurity content of machine-picked cotton is between 9%-18%.There are many types of impurity mainly including: Cotton bell shell,immature cotton peach,cotton rod,cotton leaves,hair,chemical impurities,etc;moisture content Usually between 8%-16%;the specific quality and size parameters of the impurities in the machine-picked cotton and the machine-picked cotton;the suspension speed of a single machine-picked cotton is usually between 2.6-5.6m/s,in the actual pneumatic conveying process In consideration of the difference in the physical characteristics of the machine-picked cotton and the conveying air velocity 1.8-2.0 times of the suspension velocity,the air velocity is set between 20-24m/s as the best range;The cleaning and processing principle and mechanical cleaning efficiency were analyzed.(3)According to the parameters obtained from the investigation and pre-test results,the automatic cleaning and impurity removing device for machine picking cotton is designed.Solid Works is used to complete the modeling of the cleaning and impurity removing automatic device for machine picking cotton,and the assembly is simulated and adjusted to determine the device mechanism.The device is composed of the automatic feeding and conveying part,the first impurity removal system,the drying part,the second impurity removal system and the third impurity removal part and several key mechanisms are analyzed theoretically and selected.(4)Using Flow Simulation is used to simulate the pneumatic conveying part of the automatic device for cleaning and impurity removal of machine picked cotton,and the factors such as the speed and pressure distribution of machine picked cotton in the conveying pipeline are analyzed.The simulation results verify the rationality of the design of the pneumatic conveying mechanism in the device,and the mechanism optimization and simulation test analysis of some mechanisms are carried out,as well as the thermal source simulation analysis of the drying mechanism Finally,the single factor test is carried out on the test platform of the small self-propelled machine cotton picking and conveying device.The test results show that the energy-saving efficiency reaches 30% and the energy-saving efficiency reaches 18.1% after adopting the energy-saving control system.