Threshing is one of the most critical parts of post-harvest operation which affects the quality and quantity of maize production.It could be done manually or mechanically.However,the objective of this study was to eva...Threshing is one of the most critical parts of post-harvest operation which affects the quality and quantity of maize production.It could be done manually or mechanically.However,the objective of this study was to evaluate the performance of a maize cob thresher fabricated at National Centre for Agricultural Mechanization(NCAM)Ilorin at three different moisture contents and analyze the result using ANOVA and bar chart as statistical tools.The average values of parameters evaluated at three different stages of moisture content(15.81%,16.79%and 17.10%)of maize cob are as follow:threshing capacity 754.20,737.38 and 720.23 kg/h;threshing efficiency 99.73%,99.63%and 99.16%;cleaning efficiency 89.82%,89.45%and 88.34%;broken grains ratio 0.84%,0.79%and 0.70%;time taken 43,44 and 45 s,respectively.The total amount of maize cob fed into the machine was 9 kg in three replicates for each of the moisture content and the average values of threshed maize of 8.08,8.05 and 7.95 kg was recovered,respectively.There was significant difference in threshing efficiency,amount of chaffs in the threshed maize and the percentage broken ration.At 17.10%moisture content,the percentage broken grain ratio was minimal.At high moisture content,more force,energy and time is required to thresh certain amount of maize cob.Also,at minimal moisture content less force and energy is required for maximum output.Therefore,considering the previous work on performance evaluation of maize cob thresher,this machine performed satisfactorily and is far better than manual method.The machine is effective,efficient,affordable and available for the small and medium scale farmers in Nigeria.展开更多
In this study,various operating parameters influencing performance of stationary grain crop threshers were established.These parameters were deduced from the established analytical models describing the underlying pri...In this study,various operating parameters influencing performance of stationary grain crop threshers were established.These parameters were deduced from the established analytical models describing the underlying principles for the crop characteristics and machine variables as factors influencing the overall machine performance of a stationary multi-crop thresher.A computer programme written in Visual Basic was used to select optimum operating performance of the threshing process in a stationary tooth–peg grain crop thresher.An IITA-popularized stationary multi-crop thresher was used to test the practical feasibility of the computer based output of the threshing process.A split–split–unit statistical design was used for data collection.The data collected were analyzed using the GENSTAT 5 statistical package with its computer programme.The results showed that graphs of data from measured thresher performance indices against the predicted data for all the established models indicated high correlation between the models and the measured data at p≤5%significance level.The minimum energy requirements for detachment of sorghum and rice were observed at the threshing cylinder speed of 500 r/min(10.5 m/s)and 615 r/min(13.0 m/s),respectively.The combination of the threshing cylinder speed of 500 r/min(10.5 m/s)and 615 r/min(13.0 m/s)at crop moisture content of 12.8%and 16.2%indicated optimum threshing conditions for sorghum and rice,respectively.展开更多
文摘Threshing is one of the most critical parts of post-harvest operation which affects the quality and quantity of maize production.It could be done manually or mechanically.However,the objective of this study was to evaluate the performance of a maize cob thresher fabricated at National Centre for Agricultural Mechanization(NCAM)Ilorin at three different moisture contents and analyze the result using ANOVA and bar chart as statistical tools.The average values of parameters evaluated at three different stages of moisture content(15.81%,16.79%and 17.10%)of maize cob are as follow:threshing capacity 754.20,737.38 and 720.23 kg/h;threshing efficiency 99.73%,99.63%and 99.16%;cleaning efficiency 89.82%,89.45%and 88.34%;broken grains ratio 0.84%,0.79%and 0.70%;time taken 43,44 and 45 s,respectively.The total amount of maize cob fed into the machine was 9 kg in three replicates for each of the moisture content and the average values of threshed maize of 8.08,8.05 and 7.95 kg was recovered,respectively.There was significant difference in threshing efficiency,amount of chaffs in the threshed maize and the percentage broken ration.At 17.10%moisture content,the percentage broken grain ratio was minimal.At high moisture content,more force,energy and time is required to thresh certain amount of maize cob.Also,at minimal moisture content less force and energy is required for maximum output.Therefore,considering the previous work on performance evaluation of maize cob thresher,this machine performed satisfactorily and is far better than manual method.The machine is effective,efficient,affordable and available for the small and medium scale farmers in Nigeria.
文摘In this study,various operating parameters influencing performance of stationary grain crop threshers were established.These parameters were deduced from the established analytical models describing the underlying principles for the crop characteristics and machine variables as factors influencing the overall machine performance of a stationary multi-crop thresher.A computer programme written in Visual Basic was used to select optimum operating performance of the threshing process in a stationary tooth–peg grain crop thresher.An IITA-popularized stationary multi-crop thresher was used to test the practical feasibility of the computer based output of the threshing process.A split–split–unit statistical design was used for data collection.The data collected were analyzed using the GENSTAT 5 statistical package with its computer programme.The results showed that graphs of data from measured thresher performance indices against the predicted data for all the established models indicated high correlation between the models and the measured data at p≤5%significance level.The minimum energy requirements for detachment of sorghum and rice were observed at the threshing cylinder speed of 500 r/min(10.5 m/s)and 615 r/min(13.0 m/s),respectively.The combination of the threshing cylinder speed of 500 r/min(10.5 m/s)and 615 r/min(13.0 m/s)at crop moisture content of 12.8%and 16.2%indicated optimum threshing conditions for sorghum and rice,respectively.
