Development of a Concentric Cylinder Locust Bean Dehuller

Idriss Audu, A. O Oloso, Bobboi Umar


A locust bean dehuller was developed so as to reduce the amount of time and labour
required in the traditional manual dehulling of African locust bean (Parkia biglobosa)
seeds, which are processed into a food condiment and flavouring agent that is popular in
many African countries. The dehuller principally consists of two concentric cylinders, a
power transmission shaft and a prime mover. The space between the two cylinders
constitutes the dehulling chamber. After design and construction, the dehuller was
evaluated based on three parameters, namely moisture content of beans, length of the
dehulling head and the speed of rotation of the inner cylinder. Tests showed that
efficiency of the machine increased linearly with increases in all the three parameters.
The throughput of the dehuller decreased with increases in moisture content and length of
dehulling head, but increased with increase in dehulling speed. The maximum values of
dehulling efficiency and throughput obtained were 70.3% and 0.51 kg/min. respectively.
This paper describes the design and performance evaluation of the dehuller as well as the
implication of the results obtained.

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