| Pig breeding industry is an important pillar industry in rural areas of China.With the continuous expansion of pig farms,the harm caused by feed dust has become an important problem faced by many breeding enterprises.At present,most domestic pig breeding enterprises are using pellet feed.The dust produced by this feed is difficult to be removed by conventional means such as air purification,and the effect is poor and the use cost is high.Therefore,the combination of dust removal operation and feeding device is a more efficient and convenient means,and an efficient dust removal and feeding device is urgently needed to solve the harm problem of feed dust.In view of the defects of the existing dust removal device and technology,based on the analysis of the physical characteristics of pellet feed,through the combination of theoretical analysis,discrete element software simulation and prototype test,a dry feed dust removal device was designed and manufactured.The main research contents are as follows:（1）Analysis of physical characteristics of pellet feed.The macroscopic characteristics of pellet feed,such as diameter,length,volume density and Angle of rerest,were studied by experimental method.Compressive strength and shear strength and other mechanical properties;Contact characteristics such as collision recovery coefficient and static friction coefficient.It provides a theoretical basis for the design and calculation of dry feed dust removal device and the simulation test of discrete element software.（2）Design of dry feed dust removal device.The dust can be raised by rotating the spiral winch and the material lifting plate,and the dust removal can be improved by water mist.According to the demand of the actual throughput,the diameter of the spiral blade D is110mm,the diameter of the spiral shaft D is 30 mm,and the rotating speed range of the spiral winch is 100～140 r/min.And through the mechanical analysis of the pellet feed on the hoisting plate,the installation Angle range of the hoisting plate is determined to be 15°～55°.The theoretical driving power of the motor is 4.95×10-3 k W by analyzing the energy consumed during the transportation of the spiral winch.Determine the basic parameters of the atomization dust removal device and the installation method of the atomization nozzle by analyzing the actual dust removal requirements of the device.According to the design requirements of the feeding device,the prototype was completed.（3）Motion simulation of feeding process in dry feed dust removal feeding device.EDEM discrete element software was used to simulate the mixed movement process of pellet feed and dust,and the movement characteristics of feed and dust flow in the device were studied.It was found that the feed discharge rate became stable and the feed flow inside the body became stable after 3s of exercise.At this time,the number of particles inside the device was basically in dynamic balance.And the simulation test shows that when the number of lifting plates is 5 and the rotation speed of spiral winch is 100r/min,the percentage of dust on the upper part of the machine reaches the maximum of 64.61%,which gives full play to the dust lifting capacity of the device.（4）Experimental study on dry feed dust removal device.With spiral twisted dragon speed,spray volume per unit time,feed plate installation Angle as test factors,collection coefficient and moisture content uniformity as evaluation index,the three factor and three level center combination test,regression model is established,and get the optimal working parameters combination for:spiral twisted dragon speed of 100 r/min,spray volume per unit time is 3.8 ml/s,feed plate installation Angle of 20°.The experimental results are as follows:the average dust removal rate of dry feed dust removal device is 89.54%,the average uniformity of water content is 93.46.Meet the design requirements.The research results can provide references for feed dust removal and feeding devices. |
