Design and fabrication of a shredder

Abstract

Over the years, the excessive use of agro-chemicals (pesticides and fertilizers) have adverse effect on the soil health and lead to declining of crop yields and quality of products. The shredding of twigs will provide an alternative for the use of agro-chemicals. For this to happen, the twigs will first be shredded into small bits making it ready for transportation and further processing. This necessitated the development of a shredder machine. The machine consists of three-phase electric motor, bearings, structural frame, cutters, hopper, shredding unit, discharge chute, belt drive and shaft. Four cutters are mounted on the shaft, which rotate by a belt drive. The power from the electric motor is transmitted to the cutter shaft through a belt drive. Cut is made inside the shredding unit due to the effect of tensile, friction and impact effect in shredding process. The twigs get shredded and the small bits are collected at the discharge chute of the shredder. The performance of the machine was evaluated and test results showed that there was a correlation between the weight of the shredded twigs and the shredding time. The shredding operation was done at 4 different time intervals (4 minutes, 8 minutes, 12 minutes and 16 minutes) with the same weight of twigs (40 kg) and the weight of small bits of twigs collected increases with time. The machine is user friendly and recommended for farmers and medium scale entrepreneurs.