Development of a Tractor Mounted Peanut Harvesting Equipment

A peanut harvesting equipment suitable for operation by a 35hp tractor has been designed, developed and tested at the Department of Biological and Agricultural Engineering, UPM, Malaysia. The equipment consists of adjustable V-shaped digging blade where the angle of penetration can be easily adjusted with the help of bolts and nuts. Double discs lifter for gripping the loosened plant above the soil surface follows the digging blade. The loosened plant enters into a threshing mechanism, which consists of two cylinders with different number of fingers to achieve the stripping operation without dragging and clogging the pods then transfers them to the tank at the end of the equipment via a conveyor. Light weight and durable materials were chosen to fabricate most of the peanut harvesting equipment parts. Therefore, in terms of weight, the equipment was lighter (about 315kg) compared with other existing machines (400kg). This facilitates easy hitching and transporting. Overall the peanut harvesting equipment was designed, fabricated, utilised and maintained using local resources and skill, with initial and fabrication cost of about US$1455. Soil moisture content was significant parameter' for harvesting peanut crop in a single operation. This new equipment was designed for higher soil moisture content. The previous machines were operated below 30% soil moisture content. It was also found suitable and efficient for harvesting peanut in rainy season. During the tests the clay soil cause digging, stripping and cleaning problems. Hence the new peanut harvesting equipment was designed to provide proper and efficient digging blade (V-shaped) with the following added features: Suitable clearance between cylinders and their concave (35 mm), suitable spacing between concave bars (25 mm) and conveyor wire mesh (20 mm). Equipment performance test achieved good results on clayey soil (Serdang Series Soils). Results from the field test show that the equipment is suitable for harvesting peanut in a single operation. The total power requirement of a single row equipment was about 15kW (20hp). The losses during digging, lifting, stripping and conveying were 6.23%, 8.65%, 5.06% and 1.96% respectively. Other peanut harvesters had higher digging and stripping losses (15% and % 9.3% respectively). The equipment pods breakage scored lower percentage at 1.91 % compared with the previous designed machines (about 8.9 %). Overall efficiency was 78.1%, considered high compared with other combines efficiencies. The peanut harvesting equipment had an average capacity of 324.9kg/h. The maximum capacity reached by the equipment was about 377.3kglh, while the previous designed harvester had a maximum capacity of337 kg/h