Development and Performance Evaluation of Watermelon Pulper Based on Mechanical Action of Crushing and Shearing Force

Abstract

Pulpers available in market have two concentric drums, one for sieving the crushed fruit pulp and other serve as housing. A motorized single drum brush type watermelon pulper was designed and fabricated unlike the available pulper in market. The pulper designed was simple, low cost, high capacity and easy to operate and required less cleaning effort and time. The pulper consist of the feed hopper, choppers, screw conveyor, cylindrical main housing with baffles, a perforated screen, juice outlet, waste outlet and a shaft with two beaters and nylon brushes. The auger conveyed the chopped fruit pieces while the beaters/brushes crushed, pressed and squeezed the fruits to extract the pulp. The motor, extraction unit shaft and chopper shaft had speed 1440, 360 and 90 respectively for effective pulp recovery. The developed pulper has an overall dimension of 890 mm × 300 mm × 300 mm and weighed 33.20 kg. The pulper has an average throughput of 1100 kg/h with an average extraction efficiency of 90.14 percent.