All parameters in terms of wet alfalfa input capacity,dry alfalfa output capacity,alfalfa stem length,rotary speed,heated air temperature,air flow velocity and number of lifting flights fixed at the interior wall of r...All parameters in terms of wet alfalfa input capacity,dry alfalfa output capacity,alfalfa stem length,rotary speed,heated air temperature,air flow velocity and number of lifting flights fixed at the interior wall of rotary dryer were integrated and derived into fourπterms based on Jiang’s principle.The drying temperature was a significant factor influencing the drying rate and the post-drying quality of alfalfa hay.An improved G.Murphy theorem with high confidence was used to design an experimental program for alfalfa drying in a rotary dryer.Aπequation was derived by using the multiplication of component equations involving the drying parameters and most of its correlation coefficients were higher than 0.99.The validation results show that most of the relative errors ofπterms were lower than 10%and are acceptable in engineering practice.This empirical equation may be used to investigate the parameter interactive effects on conveyor performance,which may be useful in the design and selection of rotary dryers for drying alfalfa hay.展开更多
A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the d...A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the dryer was 10000 g.The rotational speed of the inner drum was controlled.The thermal energy required for the dryer was provided by a solar absorber plate.The dryer per-formance was examined at three levels of rotational speed(0.21,0.42 and 0.84 r.p.m.),drum slope(1°,1.5°and 2°)and air velocity(1.7,1.8 and 1.9 m.s^(-1)).The diameter of the drum was the geometrical parameter that affected the movement of the particles and the ratio of the particle diameter to the drum diameter changed with the change in the drum diameter.Therefore,increasing the diameter of the drum caused a reduction in the repose angle of the paddy without any effect on the filling angle.The displacement of the product along the drum increased with increasing slope and rotational speed.At the lowest air velocity,the time required to remove moisture(<13%)was less.The results showed a significant reduction in cracked brown rice for the paddy dried by the drum dryer at 43-46℃ compared with those dried using a batch dryer.The highest stress-cracking index(11)was observed for the paddy with an initial moisture of 16%.The results showed that for proportional final moisture content,a longer drum should be considered to intensify the slope and rotational speed of the inner drum.展开更多
基金supported by special funding for returned personnel studying abroad by Heilongjiang Province,China(LC07C26)the Preferred Research Funding Project by Heilongjiang Province personnel departments+1 种基金the Scientific and Technological Innovation Project by the Northeast Agricultural University,China(CX006-3)the Qualified Personnel Foundation Project by the Northeast Agricultural University,China.
文摘All parameters in terms of wet alfalfa input capacity,dry alfalfa output capacity,alfalfa stem length,rotary speed,heated air temperature,air flow velocity and number of lifting flights fixed at the interior wall of rotary dryer were integrated and derived into fourπterms based on Jiang’s principle.The drying temperature was a significant factor influencing the drying rate and the post-drying quality of alfalfa hay.An improved G.Murphy theorem with high confidence was used to design an experimental program for alfalfa drying in a rotary dryer.Aπequation was derived by using the multiplication of component equations involving the drying parameters and most of its correlation coefficients were higher than 0.99.The validation results show that most of the relative errors ofπterms were lower than 10%and are acceptable in engineering practice.This empirical equation may be used to investigate the parameter interactive effects on conveyor performance,which may be useful in the design and selection of rotary dryers for drying alfalfa hay.
文摘A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the dryer was 10000 g.The rotational speed of the inner drum was controlled.The thermal energy required for the dryer was provided by a solar absorber plate.The dryer per-formance was examined at three levels of rotational speed(0.21,0.42 and 0.84 r.p.m.),drum slope(1°,1.5°and 2°)and air velocity(1.7,1.8 and 1.9 m.s^(-1)).The diameter of the drum was the geometrical parameter that affected the movement of the particles and the ratio of the particle diameter to the drum diameter changed with the change in the drum diameter.Therefore,increasing the diameter of the drum caused a reduction in the repose angle of the paddy without any effect on the filling angle.The displacement of the product along the drum increased with increasing slope and rotational speed.At the lowest air velocity,the time required to remove moisture(<13%)was less.The results showed a significant reduction in cracked brown rice for the paddy dried by the drum dryer at 43-46℃ compared with those dried using a batch dryer.The highest stress-cracking index(11)was observed for the paddy with an initial moisture of 16%.The results showed that for proportional final moisture content,a longer drum should be considered to intensify the slope and rotational speed of the inner drum.
