| Nowadays,the demand for healthy drinks with tea as raw materials is growing.The raw materials of fresh tea leaves is the key factor to determine the quality of tea,due to the environmental factors,from the process of tea picking,tea transportation to the tea processing sites,fresh tea leaves' surface itself will produce marl and has all kinds of pollution,and we must clean it and carry on surface dehydration.Current productions of centrifugal dewatering machine are almost assisted and stay on semi mechanization level,especially the tea dehydrators widely used in the market have many problems,intermittent operation,low efficiency,the tea is easy to adhere to the centrifugal cylinder wall and so on.Aiming to solving those problems,based on the research that study the stress and movement of the tea leaves particles and water particles in the centrifugal cylinder,the approach of combining EDEM and FLUENT was used to establish the 3D simulation model of centrifugal dewatering machine and dewatering process,and analysis the continuous field and the discrete field,then carry on optimization design for the continuous centrifugal fresh tea leaves dehydration machine,combined with the engineering practice.The main work and results of this paper are as follows:(1)To improve the dewatering rate and achieve continuous dewatering is the problem for centrifugal dewatering of fresh tea leaves.Based on the centrifugal dewatering principle,the study introduced a concept of increasing the dispersion of tea leaves through venting in order to improve the dewatering rate of the tea and realize automatic discharge of the tea.Use the multiphase flow coupling technology of discrete field-flow field to study the influence of the venting direction on the dispersion of dewatering of fresh tea leaves.(2)The approach of combining EDEM and FLUENT was used to establish the 3D simulation model of centrifugal dewatering machine,and analysis the continuous field and the discrete field during the dewatering process to study the effect of the speed of the centrifugal drum,the rotational speed of the screw propeller(dewatering time),the particle size of tea fresh leaves and the speed of the wind on the dehydration rate of tea fresh leaves.(3)The method of orthogonal test was used to analyze centrifugal dewatering machine,and it was found that the difference of rotation speed between centrifugal barrel and spiral body had the greatest influence on the dewatering effect in the case that the direction of blowing air was outwardly blown out of the centrifuge barrel.The centrifugal speed had the second effect on the dewatering effect.The speed of wind had the least effect on the dewatering effect.When the difference of rotation speed between centrifugal barrel and spiral body is 0.4r/s,and the centrifugal speed is 14 r/s,and the speed of wind is 14 m/s,the dewatering effect is better.(4)Based on the result of the study and combined with engineering practice,and the contrast experiments were done and studied.Based on the result of the research,the target model of 6CTS63 centrifugal dehydration machine was optimized,and the contrast experiment showed that.the optimized machine can improve the dewatering rate,the energy utilization rate and so on.Wind was set up in the centrifugal barrel to improve the dehydration rate of the fresh leaves in the centrifugal dewatering process in this paper,and the dehydration rate is improved and the continuous automatic dehydration is achieved.The simulation method of discrete field-flow field is applied to the centrifugal dewatering equipment.The research method has the advantages of low R & D investment,high efficiency,clear target,close to the theoretical results and practical results.It can be used in the research and development of other tea processing equipment and has practical engineering significance and research value. |
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