The design of a prototype rice parboiling vessel

Abstract

In Northern Ghana paddy rice is parboiled to reduce breakage on milling. In such arid areas, the rice grains can be extremely brittle and if parboiling is not carried out prior to milling, a large proportion of the milled grains ends up as brokens. Almost all rice produced in these regions, which is about 60% of the total national average, is parboiled in batches of about 40 kg by rural women. They use simple equipment and resources (cooking pots, open fires and earth drying floors) and the work is time-consuming, often laborious, and utilises large quantities of firewood and water. Rice processing is one of several income-generating activities which provides a livelihood for women (Quaye et al., 2000). The quality of parboiled rice has been shown to be be variable and does not compare favourably with imported milled rice (manful and Hammond, 1998). There was therefore the need to put in interventions to increase the batch size of the operation and also to produce a product of consistently high quality. The parboiling vessel designed and tested in Northern Ghana increased the batch size to between 80 and 100 kg, reduced the quantity of fuel utilised by about 50%, reduced the quantity of water used by 20 to 30% and considerably reduced the drudgery involved in the process