Design Of Constant Volume Roll Feeder And Optimization Of Throwing Part Structure Based On Discrete Elementof Throwing Parts

Factory farming mode is one of the main modes of freshwater fish farming in China.The main feeding mode for this farming model is manual feeding,which has high labor costs and poor feeding uniformity.At present,there is a lack of feeding machines that can be used in industrialized breeding mode,and the existing feeding machines generally have problems such as inaccurate feeding amounts and uneven feeding.Therefore,this paper designs and develops a constant volume roller feeder suitable for industrialized breeding mode,and optimizes the structure of the throwing parts of the feeder based on the discrete element method.The main research contents and conclusions of this paper are as follows:(1)The physical parameters of two fish feeds were calibrated.In this paper,the intrinsic parameters of two kinds of fish feeds were measured by bench test;The discrete element models of two kinds of fish feed were established in EDEM;Combined with bench test and simulation test,the relevant contact parameters between fish feed and contact materials and between fish feed are calibrated;The results show that the two fish feed discrete element models established in this paper and the calibrated physical parameters of fish feed can be used in discrete element simulation experiments.(2)A constant volume roller feeder suitable for industrialized breeding mode was designed and developed.The constant volume roller feeder is mainly composed of the feeding box,the rotating blanking part,the feed dispersion part,and the throwing part.The rotating blanking part adopts the method of intermittent rotating,and realizes quantitative and accurate blanking by controlling the rotation of the volume roller in the blanking part.The throwing part adopts the method of centrifugal throwing,and the scattered feed is evenly distributed in the breeding pond through the cooperation of the centrifugal rotary table and the round table baffle.(3)The discrete element method is used to optimize the structure of the throwing part of the baiting machine.The discrete element simulation model of the throwing part is established.Taking the bending angle of the centrifugal rotary table,the taper of the circular baffle and the speed of the centrifugal rotary table as the test factors and the feed distribution variation coefficient as the test index,the influence of each test factor on the feed distribution variation coefficient is analyzed through the single factor simulation test and response surface test,and the structure of the throwing part of the baiting machine is optimized.The results show that when the test object is hard pellet feed,the optimal parameter combination is that the bending angle of the centrifugal turntable is 78°,the taper of the circular baffle is 140°,and the rotating speed of the centrifugal turntable is 326r/min.at this time,the coefficient of variation of simulation distribution of hard pellet feed is0.772%;When the test object is expanded floating feed,the optimal parameter combination is that the bending angle of the centrifugal turntable is 90°,the taper of the circular baffle is 140°,and the rotating speed of the centrifugal turntable is 338r/min.at this time,the coefficient of variation of expanded floating feed simulation distribution is 0.203%.(4)The results of the discrete element simulation test are verified.The self-designed fixed roll feeder prototype was used for the verification test.The test results showed that the actual distribution variation coefficient of hard pellet feed was 0.781%,which was consistent with the simulation distribution variation coefficient of 0.772%;The actual distribution variation coefficient of expanded floating feed is 0.211%,which is consistent with the simulation distribution variation coefficient of 0.203%,which verifies the accuracy of the simulation optimization test results of the throwing parts of the baiting machine by using the discrete element method.The results showed that the crushing rate of hard pellet feed was 0.171% and that of expanded floating feed was 0.114%.The results show that the optimized feeder has a good throwing uniformity and low crushing rate.