Mechanism Research And Equipment Design Of Kiwifruit Steam Peeling Technology

The cultivation area and production of kiwifruit in China are the largest in the world.However,the export share of international market is still in a low level.Processing kiwifruit into diversified deep-processing products through the different deep processing means of kiwifruit is the key development trend to the kiwifruit industry at present.In all methods of the deep processing,the foremost step is to remove the rough and hairy peel of kiwifruit.The efficiency and quality of the peeling methods and equipments determine the scale and quality of the products.However,the drawbacks such as the low peel efficiency,poor peeling quality,and the environmental pollution limit the development of existing peeling methods and equipments.Therefore,the research and development of efficient,high peeling quality,environment-friendly kiwifruit peeling methods and equipments is the key to improving the international competitiveness of kiwifruit products of China.A new method for peeling kiwifruit: kiwifruit peeling by steam heating is put forward in this thesis on the basis of studying and summarizing the existing methods and equipment of fruit and vegetable peeling in home and abroad.Using superheated steam blanching kiwifruit in a short time,the rapid release of steam causing the decrease in pressure and making the moisture content in the epidermis of the kiwifruit rapidly evaporate to burst the peel.Then,the mechanism of steam peeling is preliminarily studied and the steam blanching equipment is designed in this thesis.The test platform is built on the basis of the simulation.The four factors that affect the effect of kiwifruit steam peeling are selected as the objects.The single factor test and orthogonal test are carried out under the self-defined peeling evaluation index.The main factors affecting the effect of kiwifruit steam peeling and the optimum technological parameters are obtained.Eight mature: steam blanching under 0.15 MPa for 50 s followed 0 ? water cooling for 20 s.Six mature: steam blanching under 0.6MPa for 20 s followed 0? water cooling for20 s.The key equipment of the kiwifruit steam peeling technology——steam blanching equipment is designed and the three dimensions model is created on the basis of the process parameters obtained in the experiment.The structure size of the cylinder,the cylinder flange and the blind plate is designed and calculated.The quick opening parts of equipment——three-petal type clamp structure is selected and the strength stress of the clamp structure is checked.At the same time,the structure of jacket,saddle,steam inlet and outlet pipe,kiwifruit frame car is designed and calculated.The key components of kiwifruit steam blanching equipment are analyzed using ANSYS Workbench.The static simulations of the three-petal type clamp structure and the blind plate connecting bearing in open state are carried out.The thermal structure coupling simulation analysis of the cylinder with jacket structure is carried out.Finally,The static simulation of the welding part of steam outlet pipe and cylinder is carried out.The stress and deformation analysis results of the dangerous parts meet the technological requirements of the equipment and ensure the safe operation of the equipment.In order to ensure the uniformity of steam blanching,the finite element analysis of the flow process of the steam from the steam inlet pipe into the equipment is carried out using Fluent software.According to the simulation results,the structure of the steam inlet pipe is designed and optimized.The size and length of the optimized seamless stainless steel pipe is ?55×4mm and1700 mm.The exhaust hole diameter of the steam pipe is 20 mm.Three pipes are connected in parallel.After optimization,the steam in the inlet pipe has better stable flow,smaller energy loss and more obvious shunt effect.The uniformity and continuity of steam flow in the equipment are excellent which provides a theoretical guarantee for the high efficiency of the equipment.