Experimental Study And Mechanism Analysis Of Paddle-wheel Total Mixed Ration Mixer

With the scale development of cow industry in our country, the advantages of total mixed ration(TMR)technology such as increasing the milk yield, reducing the incidence of disease, greatly improving the number of per capita cow have been understood and applied by more and more ranches, and the TMR mixer is the crux of the implementation of the technology. The study of TMR mixer in China started relatively late, and several developed TMR mixing equipment are mainly tracking the existing technology abroad, our country lack the autonomy of research and development of TMR mixer. At present, TMR mixing equipment of Chinese large ranches are mainly imported from abroad. On the basis of the development status of TMR mixer and the situation of China, the project of paddle-wheel TMR mixer was put forward, and the experimental prototype was developed, and thorough research was conducted, which can provide theoretical and technical support for the original research and development and the thorough research of TMR mixer in China. In this paper, main work and conclusions are as follows:(1)Based on the project of paddle-wheel TMR mixer, the experimental prototype was developed, the overall structure and main parts of it were designed.(2)The properties of experimental material(shear modulus, Poisson’s ratio, density, recovery coefficient, static friction coefficient, sliding coefficient, rolling friction coefficient, etc.) were studied and measured by the use of special equipment or apparatus in this paper.(3)The mixing principle of paddle-wheel TMR mixer was analyzed. To reveal mixing principle of the mixer, materials in the mixing chamber movement of three dimensional space the mixing chamber was divided into the circular movement around the rotating shaft and axial movement, and the main mixing process was divided into 4 districts.For further researched on mixing mechanism, using high speed camera technology analysised the material mixing process, speed, and the trajectories of fitting material in the mixing chamber. Through the circumferential movement of the material analysis shows that under the different condition, mixing chamber material circumferential trajectory curve mainly include arc and parabola, and rotor speed larger effect on the material circumferential motion.Through the analysis of the axial movement of material, mixing blade plate Angle and rotor speed larger effected on axial movement of material.As long as the choised of appropriate structure and operation parameters of the machine, the material in the mixing chamber was able to form a three-dimensional space mixed movement. By analyzed the mixing process drew that the mixing process are mainly shear mixing, Convective mixing and diffusion process, and in the process of mixing with the sliding movement of material, waterfall movement and eddy motion.The main mixed way material in the mixing chamber each area was: shearing mixing in the mixed Ⅰarea, shearing and convective mixing in the mixed area Ⅱ, shearing mixing and diffusion spread in the mixed area, Ⅲshearing mixing and convective mixing in the mixed area.Ⅳ(4)Based on the discrete element method used software EDEM simulation analysis to Paddle-wheel total mixed ration mixer.For the actual situation of experimental material in this study, Modeling of evaluation model to the experimental material granule 、 quantity and mixing uniformity.Through the simulation analysis concluded that the rotor speed, mixing plate angle, fullness of coefficient and mixing time has a great influence on the mixing process of material, and deviation coefficient as evaluation indicators, through simulation experimental confirmed the appropriate of structure and operation parameters when the deviation coefficient was low value range, provide a reference for determining the scope and parameter optimization for experimental factors.material deviation coefficient curve show that selected the size of the particles close to concentrate particles as tracer, then the results were more close to the mixing uniformity actual values, the conclusion can provide reference for the Paddle-wheel total mixed ration mixer selection tracer for mixing uniformity experiment.(5)Rotor speed, mixing plate angle, mixing time and fullness coefficient were decided as experimental factors, and mixing uniformity and power consumption per ton were chosen as the evaluation indexes, experimental study on paddle-wheel TMR mixer were done. By mixing experiment analysis, it could be obtained that rotor speed, mixing plate angle, mixing time and fullness coefficient had greater influences on the mixing uniformity and power consumption per ton of the paddle-wheel TMR mixer, and rotor speed had greatest influences than the other ones. By comprehensive analysis, the main parameters in structure and motion of the paddle-wheel TMR mixer were optimized and determined as follows: rotor speed 29~30 r/min, mixing time 10~11min, fullness coefficient 51%~53%, the angle of the mixing paddle 16°~18°.