Design, Development and Testing of a Neem Seed Steam Roaster

Abstract

A neem seed roaster which makes use of steam as source of heat energy was designed and fabricated to be used in heating neem seeds prior to expelling oil from them. It helps to check the disadvantage of using seed scorchers which produces burnt or unevenly heated seeds which results in black oil formation. The equipment consists of an insulated heating unit, roaster, seed inlet unit, seed discharge outlet, power transmission unit and the frame work. A gear motor of 0.25kW was selected to supply power to the shaft whose end was welded to the stirrer. The roasting unit consists of three compartments: roasting chamber, steam chamber and insulator chamber. The insulated heating unit has two pipes: water inlet pipe and steam delivery pipe. Also, two electric heating elements of 2.75kW each were installed in the heating unit to help boil the water for steam to form; this steam will then be transported by the steam delivery pipe to the steam chamber which in turn heats up the outer surface of the roasting chamber and thus the seeds inside are roasted through the heat being supplied. The machine was fabricated with about 90% local materials. Test results of the seed roaster using neem seeds indicate successful heating/roasting, the seeds were not scorched or burnt, rather they were looking dry but fresh, this indicates that the design of the machine suits its purpose for heating neem seeds prior to oil expelling . The machine being a simple one will be easy to maintain by the local artisans.