Design and Performance Evaluation of a Variable Speed Bucket Elevator

Abstract

The bucket elevator was designed and constructed at the Federal University of Technology Owerri, Imo state, Nigeria. A variable speed bucket elevator with dimensions of 0.3 m by 0.243 m and 0.47 m high with a base stand of 0.47 m high making the total height of 0.9 m was designed, evaluated and tested to determine the throughput capacity of the machine, which gave 0.176 tons h-1 at higher speed of 0.5 m s-1 with optimal efficiency at the centrifugal discharge force of 0.366 N when grain (cowpea) was elevated, and a throughput capacity of 0.109 tons h-1 at a slower speed of 0.4 m s-1 with optimal efficiency of 7.78% at the gravitational discharge force of 0.392 N when small lumpy material was elevated. 0.5 m s-1 and 0.4 m s-1 used for the experiment were obtained from the grooved step pulley with variable diameters, connected to a motor of 0.18 kW (1340 rpm) at the head, with a gear reducer of 189.7 rpm coupled to a vee belt. The result obtained during test running of the prototype model of the bucket elevator conveyor, shows that at variable speed, bucket elevator can convey different materials, which becomes an advantage instead of installing different conveyor while the same can perform the same function with a change in the pulley. This will become advantageous to low-income countries, where resources are meager to purchase different equipment whereas, a well-designed single elevator can perform variably and obtain same outcome.