|Small Scale Processing of Oilfruits and Oilseeds (GTZ, 1989, 100 p.)|
|5. Selected Equipment|
|5.2 Motorized equipment|
TCC, Kumasi, Ghana
To replace the hand pounding for digesting the fruit before pressing, TCC developed a motorized pounding machine (see Figure 10). The machine consists of a horizontal cylinder, equipped with an inlet funnel on one side and an outlet on the other. A helical screw rotates within the cylinder driven by an 8 HP diesel engine.
The pounder operates continuously at a rate of about 100 kg per hour. As a TCC press has a capacity of 50 kg per hour? the pounding machine has to be combined with two TCC presses. The pounding time is about 10 minutes (which seems relatively short), since no steam for heating is applied. Oil recovery from tenera fruit is reported to be reasonable: 26.51 or 25 kg from 100 kg fruit, which is about 17 % on bunches.
In 1985 the price of the pounder amounted to C (Cedis) 28 000 (US $ 535), excluding the diesel engine. Processing capacity and estimated investment for a complete unit is given in Chapter 4.3.
OPC, Douala, Cameroon
OPC manufactures the equipment as developed by APICA. APICA has developed the CALTECH continuous screw press in principle for hand-operation (see Figure 11 ). However, in practice the machine has to be motor-driven, as the effort required is too much to be continued longer than 30 minutes per day by the same men. When motor-driven, the press should be equipped with an electric motor or a petrol engine (2.3 HP = 1.7 kW; 2000 rpm).
When motor driven, its capacity is 200 kg cooked tenera palm fruit per hour with an extraction rate of 17 % for bunches. (see Table 8.). The machine is particularly suitable for processing of tenera palm fruit. The result with aura palm fruit is less impressive.
Prices (1987 ex- factory) are:
- Manually operated version (80-105 kg fruit/h): F CFA 1.080
- Motorized (petrol) version (150-200 kg fruit/h): F CFA 1.800 000
OPC manufactures also the screw press as originally built by the French firm Colin (now Speichim). This press is available in a manually operated and a motorized version, as well.
Prices (1987 ex-factory) are:
- Manually operated version (110-150 kg fruit/h): F CFA 3 000
- Motorized (petrol) version (275-375 kg fruit/h): F CFA 4 110 000
SPEICHIM, Bondy, France
The expeller press, as originally developed by COLIN (see 2.2.1) is at present offered by SPEICHIM. Two sizes are produced, the so-called single screw press M-10" being the smallest.
This press consists of a perforated cage in which a screw with a special profile turns to realize two functions. After feeding and compacting, the mass is pressed by a counteracting effect of the screw. During the pressing stage, transport of the mass is continued until it reaches the end of the cage. Backpressure is controlled with a control valve at the end of the cage.
Figure 34: Speichim Expeller Press. Source: GRET, 1984, p. 18, after APICA
The cage is equipped with bars to prevent rotation of the cake. Cage and screw are both manufactured from wear- resistant steel. In case the screw becomes damaged by wear it can be reshaped by welding. The screw turns at 5-10 rpm, when driven by a petrol engine of 4.5 HP. The press is equipped with a gear reduction box with ratio 1/150. Empty weight of the press is 400 kg. Its processing capacity is about 300 kg cooked tenera palm fruit per hour. The price of the press (1983, c.i.f., West Africa), is about F.F. 70 000.
Oil recovery depends on rawmaterial and which process is followed.