The discrete element method(DEM) has been widely used to simulate microscopic interactions between particles.Screening is a deeply complicated process when considering the law of motion for the particles,themselves.In...The discrete element method(DEM) has been widely used to simulate microscopic interactions between particles.Screening is a deeply complicated process when considering the law of motion for the particles,themselves.In this paper,a numerical model for the study of a particle screening process using the DEM is presented.Special attention was paid to the modeling of a vibrating screen that allows particles to pass through,or to rebound,when approaching the screen surface.Inferences concerning screen length and vibrating frequency as they relate to screening efficiency were studied.The conclusions were:three-dimensional simulation of screening efficiency along the screen length follows an exponential distribution;when the sieve vibrates over a certain frequency range the screening efficiency is stable;and,higher vibration frequencies can improve the handling capacity of the screening machine.展开更多
The adsorption behavior of thiophene and benzene on NiY zeolite has been investigated by the frequency response(FR) method.The FR spectra of thiophene and benzene on NiY zeolite were recorded at 302-335 K in a pressur...The adsorption behavior of thiophene and benzene on NiY zeolite has been investigated by the frequency response(FR) method.The FR spectra of thiophene and benzene on NiY zeolite were recorded at 302-335 K in a pressure range of 26.6-266 Pa.The results showed that adsorption was found to be the rate-controlling process for the thiophene/NiY zeolite system,and there were two different adsorption processes.Two kinds of adsorption models have been proposed,namely:the S-M interaction(low frequency adsorption) and the π-complexation(high frequency adsorption).High frequency adsorption obeyed the Langmuir model.By combining the FR method and Langmuir model,the adsorption site of high frequency adsorption process at 302 K and 335 K was 3.172 mmol/g and 2.974 mmol/g,respectively,and on the combined adsorption isotherms,the adsorption site of the low frequency adsorption process at 302 K and 335 K was 0.308 mmol/gand 0.436 mmol/g,respectively.The low frequency adsorption process(S-M interaction) was the main adsorption process.The diffusion process was the rate-controlling process for the benzene-NiY zeolite system.展开更多
基金Project 2006HZ0002-2 supported by the Special Topic Fund of Key Science and Technology of Fujian Province
文摘The discrete element method(DEM) has been widely used to simulate microscopic interactions between particles.Screening is a deeply complicated process when considering the law of motion for the particles,themselves.In this paper,a numerical model for the study of a particle screening process using the DEM is presented.Special attention was paid to the modeling of a vibrating screen that allows particles to pass through,or to rebound,when approaching the screen surface.Inferences concerning screen length and vibrating frequency as they relate to screening efficiency were studied.The conclusions were:three-dimensional simulation of screening efficiency along the screen length follows an exponential distribution;when the sieve vibrates over a certain frequency range the screening efficiency is stable;and,higher vibration frequencies can improve the handling capacity of the screening machine.
基金the National Natural Science Foundation of China(NSFC.Contract No.20546003 and No.20776064)
文摘The adsorption behavior of thiophene and benzene on NiY zeolite has been investigated by the frequency response(FR) method.The FR spectra of thiophene and benzene on NiY zeolite were recorded at 302-335 K in a pressure range of 26.6-266 Pa.The results showed that adsorption was found to be the rate-controlling process for the thiophene/NiY zeolite system,and there were two different adsorption processes.Two kinds of adsorption models have been proposed,namely:the S-M interaction(low frequency adsorption) and the π-complexation(high frequency adsorption).High frequency adsorption obeyed the Langmuir model.By combining the FR method and Langmuir model,the adsorption site of high frequency adsorption process at 302 K and 335 K was 3.172 mmol/g and 2.974 mmol/g,respectively,and on the combined adsorption isotherms,the adsorption site of the low frequency adsorption process at 302 K and 335 K was 0.308 mmol/gand 0.436 mmol/g,respectively.The low frequency adsorption process(S-M interaction) was the main adsorption process.The diffusion process was the rate-controlling process for the benzene-NiY zeolite system.
