| Banana is a popular fruit which has large area of planting in the south of our country and other tropical areas.With banana stem harvest every year there are a lot of the waste residue,if not timely treatment can cause serious pollution to the environment,and cause the waste of resources.Related research and test results slow that the banana fiber is excellent and can be used for textile and other applications.Using mechanical method to extract the banana fiber in our country has a short development time;what's more,automatic processing is not too mature.Rolling and scraping banana stem fiber extraction machine is a good scale extraction models,however the machine is still found insufficient through a large number of trials.The optimization and improvement of mechanical mechanism is helpful to the development of the mechanical production of banana fiber.The main optimization for the banana stem fiber extractor is the parameters optimization and some parts of the re design or improvement.Banana stem fiber extraction machine exist lots of defects which are found by experiments,such as blockage,noise and seriously broken fiber.The extraction of fiber and the extraction of crude fiber are directly affected by the quality of the fiber.Combined with fiber extraction process and the actual processing requirements,the design of machine structure and parameter are optimized to improve and redesign.The design and simulation software are used in the optimization process,such as CAD,CREO and ANSYS workbench.The specific optimization includes:(1)It introduces the composition,physical properties of banana fiber,as well as to optimize the rolling scraping type of banana stem fiber extraction machine structure and working principle.(2)In the form ofcontinuous and a large number of trials,it is found that the defects of fiber extraction machine with a brief description of the causes of defects.According to the speed and the moving fixed knives' gap,preliminary findings for monolithic stem fiber extraction,when the knife wheel speed is about 1300 r/min,crude fiber has the highest extraction rate and impurity rate.In the test speed within the range of 1100-1870 r/min,the gap is a main factor to determine the crude fiber in the parameters when it is fed more than three stalks at a time.(3)In order to reduce the size of the machine,the layout of the motor is adjusted,which can be easy to transport and use.To reduce the noise of the machine and the airflow speed of discharging mouth,it is need to redesign cover structure of the machine.Based on the optimum speed of the knife wheel,the transmission mechanism is improved.In order to solve the congestion problem,replaced the belt,enlarge delivery rollers'diameter and Improved baffle structure are putted forward.Fiber extraction is divided into six processes.The important parameters of the scraping knife play a role in the different process,which is used to optimization.The fixed blade structure is redesigned and the number of knife installation is optimized to 10,meanwhile the installation angle is adjusted to 80 degrees.(4)The blade and its improved structure are analyzed by structural statics,and compared the results.The results show that the improved scheme is more excellent in all aspects and is feasible.Modal analysis is carried out on the knife wheel,which found that knife wheel's speed range in more than 2123 r/min or less than 1737 r/min does not appear the resonance.The original speed will appear resonance and the knife shaft will be bending.The speed of 1300r/min is in this range which is determined by experiment.(5)To formulate the corresponding experiment method to verify the rationality of the partial improvement,it is found that the reduction of the speed of the cutter wheel has a significant effect on the noise reduction,the most appropriate gap is 3mm and replacement the conveyor belt for congestion has certain help. |
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