Number Simulation And Parameter Analysis Of Tea Water-Removing Process Based On Dem

Tea processing technology and equipment is the foundation of tea industry, and is important for the development of tea industry. Tea processing technology is extremely complex, so it has very high demands for processing equipment. Water-removing is the first procedure of green tea initial system, and is the key procedure, which is so critical to green tea quality. The cylinder water-removing machine has been widely used with its high efficiency and stable quality of de-enzyming leaf. So it is important for guiding production through water-removing numerical simulation and water-removing machine structure optimization.This paper is based on the prototype of6CST-50type cylinder water-removing machine, establishes a three-dimensional geometry of the barrel based on discrete element method, and has carried out thermal-mechanical coupling analysis of water-removing process. This paper has analysed the water-removing process through temperature field and stress field, has given several relevant control model, and has drawn some conclusions as below:(1) Cylinder water-removing machine has an optimum rotating speed. Excessive speed is bad for tea temperature rising rate and water-removing uniformity. Small speed will reduce the water-removing efficiency and burnt edge phenomenon will appear.(2) Compared to the posterior segment structure of cylinder, the number of guide baffle in forepart segment is conducive to increase temperature rising rate and temperature uniformity. Meanwhile, it can increase the transpiration rate.(3) The spread extent of tea in the water-removing process, which is good for improving tea mixing quality and tea temperature rising rate, could be improved by increasing proper angle of guide baffle and using L-shaped guide baffle. When the angle of guide baffle is increasing, the shear stress on tea is also increasing, which is good for the shape of tea.(4) Under the premise of water-removing quality, the average temperature of cylinder wall has a double exponential relationship with the cylinder angle, while the water-removing efficiency has a quadratic function relationship with the cylinder angle.This paper has optimized the structure and movement parameters of cylinder water-removing machine based on the study above. After conducting contrast test, it is considered that the optimized water-removing machine has advantages in water-removing quality, production efficiency and energy efficiency.