Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 22: 1294 - 1298. Published October 7, 2009.
Fabrication and testing of a pulveriser for starch extraction from cassava in Malawi
Nthonyiwa, A.*, Hesse, H.**^, Makutu, L.***, Mahungu, N.*, Mkumbira, J.*, Mhone, A.*, Moyo,C.*, Sandifolo, V.* and Jumbo, S*.
* IITA/SARRNET, P.O. Box 30258, Lilongwe 3, Malawi; ** Engineers without borders, Ontario, Canada; *** C To C Engineering and Foundry, P.O. Box 619, Lilongwe, Malawi.
^Corresponding author email: hhesse@gmail.com
ABSTRACT
Objectives: A pulverizer for extracting starch from cassava was fabricated and tested at Masinda Cassava Starch Cooperative Society in Malawi.
Methodology and results: The pulveriser was fabricated locally mainly of mild steel. The pulveriser was cylindrical drum shaped measuring 900 millimetres long, 900 millimetres high and with a diameter of 300 millimetres. Inside the pulveriser, there was a shaft (40 mm long) with twelve rotating spines of 40mm wide, 4mm thick and 140mm long. The pulveriser was coupled to a 3.5horse power petrol engine with a speed of 750 revolutions per minute (rpm). The driver pulley had a diameter of 75mm while the driven pulley had a diameter of 150mm. The cost of the pulveriser was USD 462 including the engine. When tested, the pulveriser significantly (P<0.05) increased starch extraction from cassava to 21% as compared to grating only yields 18% of starch. The cost benefit ratio was 0.74.
Conclusion and application of findings: The pulveriser increases the starch extraction efficiency from cassava and it is economically viable to operate. However, it is more suitable for individual medium scale processors or small scale processors under a cooperative or an association due to the relatively high cost of installing, which is over US$ 400.
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