During the grinding train operation process,the grinding force between the grinding wheel and the rail is critical in ensuring the grinding quality and efficiency.The coupling vibration among the frame,the grinding wh...During the grinding train operation process,the grinding force between the grinding wheel and the rail is critical in ensuring the grinding quality and efficiency.The coupling vibration among the frame,the grinding wheels,and the wheelsets will seriously affect the stability of the grinding force.In this paper,the coupled mechanical model of the grinding wheel/rail is established based on the contact mechanics theory,which is embedded as a submodel into the dynamic model of the multi-rigid buggy.The interaction among the frame,the grinding wheels and the wheelsets is analysed by setting the convex irregularity on the rail.The grinding effect is evaluated in combination with the subway’s long wave corrugation grinding conditions.The results show that when the grinding buggy passes the convex irregularity,the vibration excited by the wheelset system has a significant impact on the dynamic behavior of the grinding wheels.The vibration of the grinding wheel is mainly transmitted between the grinding wheel and the frame,less affecting the wheelset.For the long wave corrugation of the subway,the grinding effect of the grinding wheel has a certain correlation with the phase angle of the wheelset through the corrugation.The research results provide an important reference for the setting of the grinding pattern.展开更多
To explore the effects of low temperature and washing on the superfine grinding performance of wheat bran,two types of wheat bran samples were prepared:unwashed wheat bran(UWB)and washed wheat bran(WWB).The vibration ...To explore the effects of low temperature and washing on the superfine grinding performance of wheat bran,two types of wheat bran samples were prepared:unwashed wheat bran(UWB)and washed wheat bran(WWB).The vibration grinding experiments of UWB and WWB were carried out at different grinding temperatures by using the low-temperature vibration grinding experimental platform.The results showed that the powder quality of UWB was greatly affected by low temperature,and the effect of low temperature on the WWB was less obvious.The results also showed that the particle size distribution curve of the UWB micro powder changed from a double peak curve to a single peak curve as the grinding temperature decreased.The similarity of the particle size distribution curves of the two types of wheat bran micro powder decreased with the decrease in grinding temperature,and the maximum decrease was about 60%.Compared with the results obtained at ambient temperature,the maximum difference rates of the mass fractions of the two types of wheat bran superfine powder within the grinding temperature range were 29.91%and 50.16%,respectively.At the same grinding temperature,the difference in mass fraction between the two types of wheat bran superfine powder was about 50%.The sensitivity of the yield of UWB superfine powder to grinding temperature was greater than that of WWB.The difficulty of superfine grinding of WWB was greater than that of UWB.According to the laminate theory of composite materials,the essence of the changes in the particle size of UWB superfine powder was revealed,and the relationship between the mass fraction of residual endosperm superfine powder and the grinding temperature was obtained.The results can be applied to improve the yield and quality of the further processing of wheat bran.展开更多
The vibration mill is a high-efficiency ultrafine grinding device;its dynamic char-acteristics,along with the motion of the grinding medium,directly influence both grinding efficiency and product quality.However,there...The vibration mill is a high-efficiency ultrafine grinding device;its dynamic char-acteristics,along with the motion of the grinding medium,directly influence both grinding efficiency and product quality.However,there is a challenge in efficiently simulating the complex behavior of the grinding media within vibratory mills to maximize energy efficiency and enhance grinding performance.To bridge this,the research employs an integrated kinematic-discrete element method-experimental approach specifically designed for eccentric vibration mills.Kinematic analysis reveals that the mill's motion follows a crank-slider mechanism.Engineering discrete element method(EDEM)simulations,experimentally validated through grinding tests,were used to analyze media collision dynamics(including frequency,contact forces,energy distribution,and trajectories)at filling rates of 60%,70%,80%,and 90%.The results indicate that an 80%media filling rate optimizes performance:the collision number is 36035,contact force reaches about 450 N,showing a wave form of a sine function.Through an actual test of the grinding effect under different media filling rates,the newly generated−0.018 mm size fraction content and grinding efficiency reach their highest levels at 0.441 t/m^(3)·h and 0.00557 t/kW·h,respectively.The particle size distribution of the ground material is uniform,validating simulation rationality.Conversely,60%and 70%filling rates yielded suboptimal grinding efficiency,while a 90%filling rate sharply reduces both efficiency and product uniformity due to concentric media motion and low contact forces.This work successfully maps the relationship between filling rate and crushing energy efficiency,provid-ing a validated framework for the operation of eccentric vibratory mills.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.52475137)Sichuan Provincial Science and Technology Program(Grant No.2024YFHZ0280)Sichuan Provincial Nature and Science Foundation Innovation Research Group Project(Grant No.2023NSFSC1975).
文摘During the grinding train operation process,the grinding force between the grinding wheel and the rail is critical in ensuring the grinding quality and efficiency.The coupling vibration among the frame,the grinding wheels,and the wheelsets will seriously affect the stability of the grinding force.In this paper,the coupled mechanical model of the grinding wheel/rail is established based on the contact mechanics theory,which is embedded as a submodel into the dynamic model of the multi-rigid buggy.The interaction among the frame,the grinding wheels and the wheelsets is analysed by setting the convex irregularity on the rail.The grinding effect is evaluated in combination with the subway’s long wave corrugation grinding conditions.The results show that when the grinding buggy passes the convex irregularity,the vibration excited by the wheelset system has a significant impact on the dynamic behavior of the grinding wheels.The vibration of the grinding wheel is mainly transmitted between the grinding wheel and the frame,less affecting the wheelset.For the long wave corrugation of the subway,the grinding effect of the grinding wheel has a certain correlation with the phase angle of the wheelset through the corrugation.The research results provide an important reference for the setting of the grinding pattern.
基金supported by the Science and Technology Research Project of Henan(Grant No.212102110312)the Joint Fund of Henan Provincial Science and Technology Research and Development Plan(Grant No.232103810087)+1 种基金the R&D Special Fund Subsidy Research Project of Zhengzhou(Grant No.22ZZRDZX14)the Scientific Research Foundation for Advanced Talents of Henan University of Technology(Grant No.2020BS020)。
文摘To explore the effects of low temperature and washing on the superfine grinding performance of wheat bran,two types of wheat bran samples were prepared:unwashed wheat bran(UWB)and washed wheat bran(WWB).The vibration grinding experiments of UWB and WWB were carried out at different grinding temperatures by using the low-temperature vibration grinding experimental platform.The results showed that the powder quality of UWB was greatly affected by low temperature,and the effect of low temperature on the WWB was less obvious.The results also showed that the particle size distribution curve of the UWB micro powder changed from a double peak curve to a single peak curve as the grinding temperature decreased.The similarity of the particle size distribution curves of the two types of wheat bran micro powder decreased with the decrease in grinding temperature,and the maximum decrease was about 60%.Compared with the results obtained at ambient temperature,the maximum difference rates of the mass fractions of the two types of wheat bran superfine powder within the grinding temperature range were 29.91%and 50.16%,respectively.At the same grinding temperature,the difference in mass fraction between the two types of wheat bran superfine powder was about 50%.The sensitivity of the yield of UWB superfine powder to grinding temperature was greater than that of WWB.The difficulty of superfine grinding of WWB was greater than that of UWB.According to the laminate theory of composite materials,the essence of the changes in the particle size of UWB superfine powder was revealed,and the relationship between the mass fraction of residual endosperm superfine powder and the grinding temperature was obtained.The results can be applied to improve the yield and quality of the further processing of wheat bran.
基金funded by Hebei Province innovation ability improvement plan project(23564201D)Open Foundation of State Key Laboratory of Mineral Processing(BGRIMM-KJSKL-2021-21).
文摘The vibration mill is a high-efficiency ultrafine grinding device;its dynamic char-acteristics,along with the motion of the grinding medium,directly influence both grinding efficiency and product quality.However,there is a challenge in efficiently simulating the complex behavior of the grinding media within vibratory mills to maximize energy efficiency and enhance grinding performance.To bridge this,the research employs an integrated kinematic-discrete element method-experimental approach specifically designed for eccentric vibration mills.Kinematic analysis reveals that the mill's motion follows a crank-slider mechanism.Engineering discrete element method(EDEM)simulations,experimentally validated through grinding tests,were used to analyze media collision dynamics(including frequency,contact forces,energy distribution,and trajectories)at filling rates of 60%,70%,80%,and 90%.The results indicate that an 80%media filling rate optimizes performance:the collision number is 36035,contact force reaches about 450 N,showing a wave form of a sine function.Through an actual test of the grinding effect under different media filling rates,the newly generated−0.018 mm size fraction content and grinding efficiency reach their highest levels at 0.441 t/m^(3)·h and 0.00557 t/kW·h,respectively.The particle size distribution of the ground material is uniform,validating simulation rationality.Conversely,60%and 70%filling rates yielded suboptimal grinding efficiency,while a 90%filling rate sharply reduces both efficiency and product uniformity due to concentric media motion and low contact forces.This work successfully maps the relationship between filling rate and crushing energy efficiency,provid-ing a validated framework for the operation of eccentric vibratory mills.
