Mechanism Analysis And Experimental Study Of The Tumble Ration Mixer

With the scale and intensive development of foreign and domestic ruminant animal breeding industry,as well as the improvement of raise and management level,total mixed ration breeding technology has been widely used in ruminant farms,and the key to the implementation of total mixed ration breeding technology is the configuration of ration mixer.The study of ration mixer in China was carried out relatively late,and the current study is mainly focused on the study and development and experimental study on several mature models.There are few innovative studies based on the mixing mechanism of ration mixer,and it is still in the stage of development.Therefore,based on the actual demand of the ruminant animal breeding industry in China and the study status of ration mixer,a tumble ration mixer was put forward,and the comprehensive study method of theoretical analysis,high-speed photography technology,simulation analysis and experimental study was used in the course of in-depth study of its mixing mechanism and mixing performance.The main study contents and results were as follows:(1)Study on the characteristics of components of the experimental ration.According to the different properties of the material components of ruminants,the typical representative feed materials were chosen as the experimental ration,and basic and rheological mechanical characteristics of each material component were measured to obtain the wet moisture content of the material,geometric characteristics,density,shear modulus,Poisson’s ratio,collision recovery coefficient and friction coefficient.The study content was used to provide support for the study of the particle model establishment of each material component during the discrete element simulation analysis and the study of the tumble ration mixer.(2)Design of experimental platform of the tumble ration mixer.On the basis of analysis,a hollow-positive-decagonal tumble ration mixer was proposed,and key structures such as the main mixing work mechanism and supplementary system were designed and analyzed.Based on the above analysis,experimental platform of the tumble ration mixer was designed,and the comprehensive study and analysis of the representative tumble ration mixer without shoveling plate and with shoveling plate were performed,which was helpful for further in-depth innovative study.(3)Mechanism analysis and experimental study of mixing performance of the tumble ration mixer without/with shoveling plate.Using the theoretical analysis,simulation analysis and high-speed photography technology,the mixing mechanism analysis results of the tumble ration mixer without shoveling plate and with shoveling plate showed that: according to the movement characteristics of material particle group in the drum of the tumble ration mixer without shoveling plate,the material distribution area was divided into follow-up area,disturbance area,and rolling area(main mixing area),and the mixing movement of the material particles in the follow-up area was dominated by weaker shear mixing,the mixing movement of the material particles in the disturbance area was dominated by weaker shear mixing and diffusion mixing,the mixing movement of the material particles in the rolling area was dominated by a small range of shear mixing and diffusion mixing.According to the movement characteristics of material particle group in the drum of the tumble ration mixer with shoveling plate,the material distribution area was divided into lifting area,throwing area,and returning area,and the mixing movement of the material particles in the lifting area was dominated by shear mixing,the mixing movement of the material particles in the throwing area was dominated by main shear mixing and diffusion mixing and auxiliary convection mixing,the mixing movement of the material particles in the returning area was dominated by weaker shear mixing.The location,size and shape of each movement area were greatly affected by the structural and operating parameters.Results of the experimental study by the usage of the experimental platform of the tumble ration mixer showed that: for the tumble ration mixer without shoveling plate,the descending order of influence of experimental factors on coefficient of variation was loading rate of materials,mixing time and rotary speed of drum;And the descending order of influence of experimental factors on net power consumption was mixing time,rotary speed of drum and loading rate of materials;The optimal parameter combination scheme was rotary speed of drum 22 r/min,loading rate of materials 51%,mixing time 12 min,and coefficient of variation and net power consumption were 5.86% and 39.75 kJ,respectively.For the tumble ration mixer with shoveling plate,the descending order of influence of experimental factors on coefficient of variation was inclination angle of shoveling plate,rotary speed of drum,loading rate of materials,mixing time and height of shoveling plate;And the descending order of influence of experimental factors on net power consumption was mixing time,rotary speed of drum,loading rate of materials,inclination angle of shoveling plate and height of shoveling plate;The optimal parameter combination scheme was rotary speed of drum 23.5 r/min,loading rate of materials 65%,mixing time 4 min,inclination angle of shoveling plate 11° and height of shoveling plate 109 mm,and coefficient of variation and net power consumption were 2.09% and 33.73 kJ,respectively;The mixing condition of the tumble ration mixer with shoveling plate was better than that of the tumble ration mixer without shoveling plate.(4)Mechanism analysis and experimental study of the tumble ration mixer with paddle.On the basis of the above study work,a tumble ration mixing experimental device with paddle was proposed.Using the theoretical analysis and high-speed photography technology,the mixing mechanism analysis results showed that: in the rotating process of drum,there were a small range of circulation mixing in a part of drum that realized through the support of drum to materials,and a large range of circulation mixing in the upper part of drum that realized through the combined support and convey of drum and paddles,the uniform mixing of material particles was realized repeatedly and quickly.Results of the experimental study by the usage of the tumble ration mixer experimental device with paddle and the measuring system showed that: the descending order of influence of experimental factors on coefficient of variation was loading rate of materials,rotary speed of drum,mixing time and gyrating radius of paddle;And the descending order of influence of experimental factors on net power consumption was mixing time,rotary speed of drum,loading rate of materials and gyrating radius of paddle;The optimal parameter combination scheme was mixing time 3.5 min,loading rate of materials 66%,rotary speed of drum 29 r/min,gyrating radius of paddle 236 mm,and coefficient of variation and net power consumption were 7.02% and 32.62 kJ,respectively;The mixing condition of the tumble ration mixer with paddle was better than that of the tumble ration mixer with shoveling plate.The study content is of practical significance in improving the theory of tumble ration mixer,and it will provide the basis for the study,optimization design and parameter selection of the tumble ration mixer.