Procédé d'extraction de l'huile contenue dans une pâte d'olives broyées et extracteur centrifuge perfectionné servant à la mise en oeuvre de ce procédé

摘要

A process for extracting oil from a homogenized cake of ground olives by means of a horizontal centrifugal extractor having two coaxial bowls comprises the steps of feeding the cake by small portions to the inlet of the extractor, combing the fibres contained in each small portion at its entrance into the extractor, directing the combed fibres into a centrifuging area of the extractor and submitting the fibres and other residues to a heating operation. The extractor, Fig. 1, comprises an outer bowl 4 and an inner bowl 5 having helical conveying blades 6 on its outer surface, the bowls being driven in the same direction and at adjustable differential speeds through a device 2. A partitioned casing 7 surrounding the bowls is provided with outlets 8, 9, 10 serving to evacuate respectively residues (including the fibres), aqueous juices and oil obtained in the course of the extracting process. The cake is fed via a nozzle 11 through a conduit 12 and is deflected radially into channels 22, Fig. 3, in an end plate 15 in the inner bowl 5. The channels are provided with toothed surfaces 23 for combing the fibres and lead into the space between the bowls into which space water has been previously introduced via the conduit 12, a conduit 13 provided with end perforations 14 and two conduits 17. Under the action of centrifugal force the oil and aqueous juices are separated in the part of the annular space between the bowls bounded by the cylindrical part of the outer bowl and accumulate in two layers between the helical blades 6. The oil is led by means of two grooves 24, Fig. 4, at the bottom of the blades 6 into a channel 18 bounded by a plate 19 serving to prevent mixing of the separated oil and aqueous juices, the grooves 24 being helically cut into the bowl 5 in a direction opposite to the direction of rotation of the bowl in order to exert a pumping effect. From the channel 18, the oil is evacuated via similarly helically wound tubes 25 into an annular constriction 30 in an end plate 151 for the bowl and then via orifices in the plate against a deflector 32 and a froth-preventing parabolic deflector 33 and into a trough 20 to which the outlet 10 is connected. The aqueous juices which accumulate on the other side of the plate 19 remote from the channel 18 are removed via helical tubes 26 into a constriction 27 in the plate 151 and thence to a trough 29 from which depend the outlet 9. The fibres and other residues which are separated against the wall of the bowl 4 are propelled towards the outlet 8 by the helical blades 6 and are dried, before reaching the outlet, by direct injection of steam or, as shown, indirectly by steam or warm water injected through the pipe 13 inside the bowl 5. Condensate from the interior of the bowl 5 may be passed through the conduits 17 to heat the cake as it is fed into the space between the bowls.