Research interest in pneumatic conveying technologies in processes such as peanut harvesting and shelling has grown rapidly in recent years.However,the use of pneumatic conveyors in this application suffers from high ...Research interest in pneumatic conveying technologies in processes such as peanut harvesting and shelling has grown rapidly in recent years.However,the use of pneumatic conveyors in this application suffers from high pod damage rates and duct obstruction.To address these issues,we analyzed the critical speed of pneumatic transport for conveying the peanut pods and measured the angle of friction and coefficient of restitution of peanut pods on a variety of material surfaces.Based on the results of these tests,optimizations and improvements were made to the separator bowl,air supply duct,and conveying duct.A pneumatic conveying experiment was then performed using peanut pods.In the factorial experiment,it was found that increases in fan speed increase the pod damage rate and transport efficiency,while increases in the thickness of the cushioning/anti-obstruction layer decrease the rate of pod damage and transport efficiency.Pod damage rates were significantly affected by fan speed,the thickness of the cushioning/obstruction prevention layer,and interaction between these factors,while transport efficiency was only significantly affected by fan speed.It is proved by the machine verification test,the optimal parameters for the pneumatic transport of Baisha peanut pods with a moisture content of 7.24%was a fan speed of 2700 r/min and a cushioning/anti-obstruction layer thickness of 6 mm.A pod damage rate of 5.19%and transport efficiency of 92.03%were achieved using these parameters,which are sufficient for meeting the requirements of industrial applications.展开更多
To obtain the optimal operation parameters of fixed-bed reversing ventilation drying of peanuts,a set of partial differential equations indicating the heat and mass transfer relationships between the peanut pods and a...To obtain the optimal operation parameters of fixed-bed reversing ventilation drying of peanuts,a set of partial differential equations indicating the heat and mass transfer relationships between the peanut pods and air during drying was proposed.Then,a series of discretized models were established for simulation,and the time consumed,unevenness,and energy consumption for batch drying were calculated.The results showed that reversing ventilation and segmented drying was helpful to these issues for high drying ability.The optimal operation parameters were determined by uniform design experimentation of mathematical simulation.The result showed that when the moisture content(wet basis)was above 22%,a ventilation velocity of 0.46 m/s was optimal;when the moisture content was between 8%and 22%,a ventilation velocity of 0.20 m/s was optimal.Using the optimal parameters,the computer simulating result was compared with the experimental results.The correlation coefficients between the simulating and the experimental values for the temperature and moisture content were all above 0.98 and the quality of dried peanuts was close to that of natural sun-dried ones,which indicates that the optimization results of the drying parameters are highly reliable.展开更多
文摘Research interest in pneumatic conveying technologies in processes such as peanut harvesting and shelling has grown rapidly in recent years.However,the use of pneumatic conveyors in this application suffers from high pod damage rates and duct obstruction.To address these issues,we analyzed the critical speed of pneumatic transport for conveying the peanut pods and measured the angle of friction and coefficient of restitution of peanut pods on a variety of material surfaces.Based on the results of these tests,optimizations and improvements were made to the separator bowl,air supply duct,and conveying duct.A pneumatic conveying experiment was then performed using peanut pods.In the factorial experiment,it was found that increases in fan speed increase the pod damage rate and transport efficiency,while increases in the thickness of the cushioning/anti-obstruction layer decrease the rate of pod damage and transport efficiency.Pod damage rates were significantly affected by fan speed,the thickness of the cushioning/obstruction prevention layer,and interaction between these factors,while transport efficiency was only significantly affected by fan speed.It is proved by the machine verification test,the optimal parameters for the pneumatic transport of Baisha peanut pods with a moisture content of 7.24%was a fan speed of 2700 r/min and a cushioning/anti-obstruction layer thickness of 6 mm.A pod damage rate of 5.19%and transport efficiency of 92.03%were achieved using these parameters,which are sufficient for meeting the requirements of industrial applications.
基金supported by the Special Expenses for Basic Scientific Research of the Chinese Academy of Agricultural Sciences(Grant No.S201937)New Equipment and New Technology Research,Development and Promotion Project of Jiangsu Province Agricultural Machinery(Grant No.SZ120180032).
文摘To obtain the optimal operation parameters of fixed-bed reversing ventilation drying of peanuts,a set of partial differential equations indicating the heat and mass transfer relationships between the peanut pods and air during drying was proposed.Then,a series of discretized models were established for simulation,and the time consumed,unevenness,and energy consumption for batch drying were calculated.The results showed that reversing ventilation and segmented drying was helpful to these issues for high drying ability.The optimal operation parameters were determined by uniform design experimentation of mathematical simulation.The result showed that when the moisture content(wet basis)was above 22%,a ventilation velocity of 0.46 m/s was optimal;when the moisture content was between 8%and 22%,a ventilation velocity of 0.20 m/s was optimal.Using the optimal parameters,the computer simulating result was compared with the experimental results.The correlation coefficients between the simulating and the experimental values for the temperature and moisture content were all above 0.98 and the quality of dried peanuts was close to that of natural sun-dried ones,which indicates that the optimization results of the drying parameters are highly reliable.
