Experimental Study On The Effect Of Vibration Parameters On Forage Compression Temperature

Compression molding is an effective way to solve the problem of forage storage and transportation.The extrusion deformation and friction energy consumption of materials in the compression process will increase the internal temperature of the compressed materials.Appropriate temperature rise can improve the quality of forage products and reduce the energy consumption of compression molding.In this paper,the die and the vibration excitation device of the existing biomass densification test-bench were improved and designed and the compression temperature test system was completed.The experimental research on the influence of vibration parameters on the molding temperature in the compression process was carried out with alfalfa as the raw material,and the conclusions are as follows:(1)Through the comparison test of alfalfa with and without vibration compression,it was verified that vibration can increase the temperature in the compressed material.(2)In order to remove the influence of the ambient temperature on the test,the temperature distribution test in the alfalfa during compression under the vibration force field was carried out by using the temperature-controlled silicone heating plate to provide a stable test environment for the die.The results showed that when the vibration frequency was below 15 Hz,the temperature at center and side of compressed Alfalfa increased slowly with compression time,while the vibration frequency was above 20 Hz,it increased first and then decreased with the increase of time.And as the vibration frequency increasesd,the maximum temperature appreciation of the center and the side of the compressed material increased.Moreover,the maximum temperature value increased significantly when the frequency was above 20Hz.In the same vibration frequency and compression time,the center temperature in compressed Alfalfa was higher than side temperature.In this paper,the optimum vibration compression frequency of Alfalfa was analyzed at the temperature of 20Hz,which provided reference for the following experiments.(3)Based on the open compression test system at room temperature,the side temperature of the compacted material in the process of moving,the center and the side temperature of the material in the stage of compression,the center and the side temperature of Alfalfa block after the die were studied.The experimental results showed that:under the vibration force field,the temperature rise of the moving stage was smaller than that without vibration,indicating that vibration is beneficial to reduce friction;in the process of Alfalfa compression,the center temperature and the side temperature had the same change trend,but the temperature rise value was different.The center temperature was higher than the side temperature.After the Alfalfa block was released from the die,the temperature of the core was higher than the temperature of the side.The research contents and results of this paper provide a theoretical basis for determining the optimal vibration frequency and revealing the mechanism of vibration compression.