Agro-Tech Book - Agriculture Support Programme

* Dirt, dust and all waste matter must be removed from the seed by winnowing it. Dirt
particles will wear out the piston. If seed from other farmers is being purchased for
expelling, it should be carefully checked �rst. Some local varieties have a very low oil
content and hard shells. A good test is to see how much oil can be expressed from a 5 litre
tin of seed. Seed with acceptable oil yield will 1/2 �ll a 750ml saladi bottle and good seed
will 3/4 �ll it.
* It is best for 2 people to work the press. One prepares the seed and the second operates
the press. Before pressing seed should be warmed in the sun for 15 minutes as this will
increase the extraction rate. If there is no sun the seed can be warmed over a �re in a �at
metal container. Seed should be warm to touch and not hot or burnt.
* The press should be properly set before operation commences, and as regularly as
required, by adjusting the restrictor. The press should only be operated by 1 person and the
handle should be moved up and down smoothly.
* The press should be lubricated twice a week with clari�ed oil and should be cleaned each
time 10 bags has been crushed. Boiling water is poured over the cage cylinder, and then
scrubbed with a brush. A knife is then used to remove residues caught between the cage
bars and the cage is rinsed again with boiling water.
* Oil coming out of the press will be grey. Oil can be clari�ed by allowing it to settle for 72
hours. The particles settle and the clear oil is carefully decanted off. This is the best and
most simple method of clari�cation.
• Simple daily records should be kept of:
• the amount of seed bought; from whom and how much paid (or contractually committed)
• the amount of seed crushed
• the source of the seed
• the quantity of oil (and colour)
• the labour used (cost)
• the quantity of oil sold – and income (credit or cash or barter)
• quantity of cake produced
E.E.O.A.
• the quantity of cake sold – and income (credit or cash or barter)
• Balances of Seed; oil; cake; cash
• Any problems and what action taken
The Sundhara Press, available from Jung & Co Kitwe ( tel 02 212851; 02 210476) extracts
18 litres of oil from 50 kgs of hybrid seed and is run by a 10 hp diesel or electric motor.
The expeller costs $5,150 ( 3 phase electric motor) and has an output of 200 litres of crude
oil a day. The screw worm wears out after 50-70 tons of sun�ower has been expelled. This
reduces extraction rates and the worms then have to be re-faced by the manufacturer.
Operators should have 2 spare worms so processing is not delayed during re-facing.
The business is really only suited to entrepreneurs who have large retail outlets and who
AGRO-TECHNOLOGY: Farming and Processing Equipment
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