Design And Experimental Research On Freshwater Fishes' Head And Tail Continuous Removing Device

The development of freshwater fish pre-processing technologies has a direct impact on the modernization of freshwater fisheries.The processing of freshwater fish head and tail removing is an important part of the pre-processing,it separates head and tail of fish from the fish body,improves the utilization of fish resources and determines the efficiency and quality of subsequent processing.Therefore,the development of an efficient head and tail processing equipment for freshwater fish is an important part for developing fishery modernization.In this paper,the physical characteristics of freshwater fish were studied by taking bream and grass carp as the research object.The main contents of the study are as follows: the measurement of body shape parameters,the fish head and tail shear characteristics test,and the fish body compression test.The test of fish head and tail shearing characteristics was based on the factors of flat blade slip angle,tool type,fish body temperature and tool loading speed.The effects of different factors on the maximum shear force required for cutting fish heads were studied.Then the effect of cutting fish heads with different types of tools on meat collection rate of fish was studied.The fish body compression test mainly explores the change law of the fish body under pressure from outside of fish body.The fish head and tail shear characteristics test and fish body compression test are mainly conducted on the universal testing machine for data acquisition.Through the research on the physical characteristics of freshwater fish,it provides scientific guidance and theoretical basis for the development of head and tail removing device.The main conclusions of the research on the physical characteristics of freshwater fish were as follows: 1)the shear force required for the flat knife at the skid cut angle of 30° was the smallest,and the shear force required for cutting the fish head with the sharp knife was the smallest.When bream body temperature is above-4°C and grass fish body temperature is above 4°C,it is easy to cut and the temperature has no obvious effect on the shear force.The shear force increases with the increase of the tool loading speed;2)The fish head produced by the sharp-edged knife accounted for the smallest proportion,so the meat collection rate of fish was the highest;3)The shearing force required to remove the fish tail was less than the shearing force required to remove the fish head.4)The mean value of the appearance damage point of the squid is 545.1N,and the mean value of the plastic deformation point of the curve is 1038.8N.The appearance damage point of the grass carp is the same as the plastic deformation point of the curve,and the average value is 725.0N.Comprehensively cut the required shear force of fishes' head and tail and meat collection rate of the fish.The device chooses the sharp-edged knife as head removing knife and the sharp knife as tail removing knife.In this scheme,the required shear force for head removing is 313.6N,and the shear force for tail removing is 167.1N.Therefore,the sum of shearing force required by the device is 480.7N.The maximum pressure of the fixture in the device needs to be less than the smaller value of each damage point,the value is 545.1N.The analysis of the shear force value and the maximum fixture's pressure required by the device provides a scientific basis for the design of the specific parameters of the device.Based on the study of physical characteristics of freshwater fish,a design idea combining mechanical structure and electrical control is proposed.The main contents of the device design plan are as follows: the sheave wheel mechanism realizes intermittent motion,the transmission mechanism conveys the motion to the conveyor belt to realize intermittent transportation,the cylinder-driven cutter cuts the fish body,and the positioning device uses the brush as the main body to realize the positioning of the fish body.The fixture ensures the stability of the cutter when cutting the fish body,and the electrical control system is designed to ensure the cooperation of the intermittent delivery and the cylinder movement.The success rate of head and tail processing,meat collection rate of fish,the sensory evaluation scores of the cut surface and the degree of pressure were the main evaluation indicators,and the processing effect evaluation test was conducted on the prototype.The conclusion is as follows: the success rate of bream processing is 90%,the success rate of grass carp processing is 85%;bream meat collection rate were 82.1% and grass carp meat collection rate 76.3% respectively,and the sensory evaluation scores were 0.844 to bream and 0.832 to grass carp.The rated power of the device is 2.3kW and the theoretical processing efficiency is 1350 fishes/h.