M Nurul Amin
Scientific Officer
Farm Machinery and Post harvest Process Engineering Division
Bangladesh Agricultural Research Institute
Gazipur-1701
Sultn Ahmmed
Senior Scientific Officer
Farm Machinery and Post harvest Process Engineering Division
Bangladesh Agricultural Research Institute
Gazipur-1701
K C Roy
Chief Scientific Officer
Farm Machinery and Post harvest Process Engineering Division
Bangladesh Agricultural Research Institute
Gazipur-1701
M Ayub Hossain
Scientific Officer
Farm Machinery and Post harvest Process Engineering Division
Bangladesh Agricultural Research Institute
Gazipur-1701
This study was carried out to determine the effect of moisture on frictional coefficient of chickpea, khesari, blackgram, cowpea, fieldpea, mungbean and lentil. Four levels of moisture contents of chickpea, khesari, blackgram, cowpea, fieldpea, mungbean and lentil ranging form 8.76 to 22.38 percent ( we basis) were considered in this study. Static and kinetic frictional coefficients were of these pulses determined over concrete surface, galvanized iron sheet, plywood and glass sheet. They were varied from materials to materials and depended on the rouughness and wetness of the grain. The highest frictional coefficient of static and kinetic was found over concrete surface and lowest for glass sheet among the materials tested. The highest value of frictional coefficient of static and kinetic has been found for chickpea, which indicates its rough surface than those of other six. The static frictional coefficient irrespective of grain and surface types was always greater than the kinetic frictional coefficients.
Blackgram, cowpea, fieldpea, frictional coefficient, mungbean
Farm Mechanization
Determination of frictional coefficients of pulses on concrete galyanized iron sheet, plywood and glass sheet at four moisture contents
Sample preparation:
The study was conducted at Farm Machinery and Postharvest Process Engineering Division of Bangladesh Agricultural Research Institute Gazipur during, April- May 2003. Dried pulses were collect from Pulse Research Center of BARI. The initial moisture content was determined by drying samples in an air ventilated oven at 103 c temperature for 72 hours (ASAE, 1993). The samples of the selected moisture content were determined by adding calculated amount of water and sealing them in separate polyethylene bags and stored in a refrigerator at 7o C. Before each experiment, the required sample was taken out from the refrigerator and kept in ambient condition for 24 hours to equi9librate the water and temperature throughout the sample. Static and kinetic frictional coefficients of chickpea, khesari, blackgram, cowpea, fieldpea, mungneam and ;lentel, were determined on four surfaces such as smooth concrete galyanized iron sheet , plywood and glass sheet at four moisture contents ranging from 9.25-21.25, 10.28-22.28, 10.38-22.38, 8.76-20.76,10.21-22.21,9.14-21.14, and 10.33-21.00 percent (wb), respectively.
Determination of frictional coefficient:
The measurements were taken at room temperature of 30 -36o C . The static and kinetic coefficient of friction of each variety were determined on concrete, galvanized steel sheet, coefficient of friction of each variety were determined on concrete , galvanized steel sheet plywood and glass sheet . It was determined on each surface by filling a hollow plastic box of dimension 70x 70 x 70 mm with kernels as suggested by (Kaleemullah,1992) the box was pulled parallel to the surface in such a way that it just started to move and static coefficient of friction was determined by using the formula
Research Report
The static and kinetic frictional coefficients for all varieties increase with the increase of moisture content and the chickpea has the highest static and kinetic frictional coefficient compared to khesari, blackgram, cowpwa, fieldpea, mungbean and lentil. The fictional coefficients on concrete surface were found to be higher than other surfaces.
Journal, Report/Proceedings