Tomato Peeling Experiment Research And Device Optimization Based On Infrared Radiation

Tomato is one of the most widely cultivated and consumed vegetable varieties in the world.The planting area of tomatoes in the world is about 5 million.In 2018,the domestic tomato planting area was close to 1.34 million,accounting for 26% of the global tomato planting area,and the tomato output was about 55 million tons.The processing of tomato products has not been fully mechanized,especially the peeling process of tomatoes,which still requires a lot of labor.At present,tomato peeling mainly includes thermal peeling,alkaline peeling and enzyme peeling,all of which require manual assistance.The biggest difficulty in peeling by infrared radiation heating is that it is difficult to achieve uniform heating.Excessive radiant heating will make the tomato peel coked,and insufficient radiant heating will make it difficult to separate the pulp and peel.In addition,the wavelength,power,time and distance from the infrared heating tube are the key factors that affect the peeling effect.This paper explores the solution of uneven heating and optimizes the process parameters by designing test benches,which are of great significance for the processing of tomato products.The main research contents and conclusions are as follows:(1)In order to explore its mechanical properties,the texture tester was used to conduct compression test and peel tensile test on the large tomato "hard powder No.8" and the small tomato "Millennium" respectively.-The displacement curve can be seen,when the flat plate indenter is compressed to the position of 10-13 mm,the appearance of the tomato is broken,and it can be concluded that the force at the yield point of the large tomato is about 60 N.When the flat plate indenter is compressed to the position of 6-7mm,the compressive force reaches the maximum,the range is19-23 N,and the female fruit breaks at the position of the maximum force.The maximum pull range of tomato is 1.77-3.262 N,with an average value of 2.47 N.(2)In order to ensure the working stability and reliability of the lifting platform,the world’s mainstream CAE software ANSYS Workbench is used to analyze and solve the overall deformation,equivalent stress and equivalent strain of the scissor arm.Scissor arm is the main part of the deformation due to excessive hinge holes,so CFD meshing is used.The finite element model of the scissors arm has 1768 nodes and 1068 elements.It can be seen from the displacement cloud of the scissors arm that the maximum deformation The amount occurs at the movable hinge part is 0.52 mm.From the stress cloud of the scissor arm,the maximum stress value is 202 MPa,which appears at the movable hinge hole.The allowable stress value of structural steel when subjected to bending,compression,and tensile It is 215 MPa,and the maximum stress of the scissor arm is less than the allowable stress,which meets the strength requirements.(3)In order to meet the needs of the experiment for height adjustment,the lifting table was designed,and the scissor lifting mechanism was selected.It has a large working stroke and a simple structure,which is more suitable for the test prototype.When the infrared transmitter is working,the hydraulic cylinder is used to horizontally push the movable hinge to achieve the lifting according to the surrounding environment temperature is too high.The initial angle between the centerline of the scissorarm of the lifting table and the base is 12°,the angle between the extreme position is 55 °,and the scissor arm is 41 cm.Considering the space occupied by the fixture and the infrared emitter and the material,the effective stroke of the lifting table is 19cm-28 cm.During the heating process of tomatoes,the phenomenon of uneven heating is often observed.To this end,a conveying mechanism capable of conveying tomatoes and driving the rotation of tomatoes is designed.Under the traction of the chain,the roller rotates on a fixed guide rail to realize the function of turning over the material.At the same time,the chain Driven by the driving sprocket to revolve and transport materials.(4)Taking the peeling grade and surface temperature of tomatoes as the test indexes,the Box-Benhnken central combination test design theory was used to analyze the peeling effect of infrared tube power,heating tube and material distance,and radiation heating time at different levels.Using Design-Expert data processing software to analyze the experimental data,the results show that the significant order of the influence on the peeling level and surface temperature is single infrared tube power> spacing between heating tube and material> radiation heating time.The optimal parameter combination form is as follows: the power of a single infrared tube is 1.17 kw,the distance between the heating tube and the material is 6.32 cm,the radiation heating time is 4.78 min,the peeling rate reaches88.5%,and the surface temperature is 115.8 ℃.