An improved extractor of oil from oily seed or fruit pastes and the like

Abstract

 A tank extractor (1) of a rectangular plan view, the bottom wall of which is substantially shaped in the form of sectors (1b) of two partially interpenetrating cylinders, between which a longitudinal channel (1c) is arranged, housing a screw (2, 2a) for the discharge of the treated paste.
The bottom walls (1b) are formed as longitudinal segments or sub-sectors (3), in which annular slits (5a, 5b) are arranged.
On the outside of each segment (3), a device (6a, 6b) is mounted comprising a longitudinal bar (8a, 8b) supporting two pluralities of small blades (9) designed to penetrate, at predetermined time intervals, through the slits (5a, 5b) so as to maintain these latter disobstructed and to entrain the oil towards the outside.
The devices (6a, 6b) are driven by means, causing the small blades (9) to enter and come out said slits radially and at predetermined time intervals.
In the tank (1) two twin kneading and mixing rotors are mounted comprising two longitudinal shafts (10a, 10b) rotating in opposite directions, each of which carries lengths of helicoidal blades (11a,11b) designed to operate in interlacing zones and which angularly extend within a cylindrical sector of an angular amplitude not higher than 180°, as well as longitudinal bars (4a, 4b) carrying comb-like devices (7a, 7b) with radial teeth (28), made of elastomeric material, and which slide along the respective inner surface of the walls (1 b). The teeth (28) are spaced apart from each other by slots so that the small blades (5) can enter into the tank (1) and then into the slots of the teeth (28) so as to clean also these latter.

Description

[0001] The present invention concerns a tank extractor for the separation of the oil from oily seed or fruit pastes, more in particular, from olive fruits, and in the inside of which two rotors having helicoidal blades rotate, one in clockwise, the other in counterclockwise direction respectively and in interlacing portions of said tank, which is provided with perforated bottom walls for the discharge of the oil therethrough and which comprises a longitudinal central bottom channel into which a screw member rotates in order to discharge the treated oily paste.

[0002] Extractors for the separation of the oil from oily pastes and the like of the press type are already known, as well as other apparatus of extractive type which treat the paste by means of one or two rotors provided with helicoidal blades in the inside of a tank having perforated bottom. Said known apparatus are designed to treat the paste in batchs so that, at predetermined time intervals, the apparatus has to be stopped and the treated paste has to be discharged, in general, by overturning the tank.

[0003] Said extractors of the known type have a reduced yield and require frequent cleaning operations of the oil discharge holes which are often obstructed by the paste.

[0004] The present invention relates to a tank extractor having an automatic charge and an automatic discharge of the treated paste, at the end of the extraction cycle, by means of a bottom channel into which a rotating screw operates so that this apparatus requires very short dwell of time.

[0005] At the upper part of the tank this latter has a parallelepiped shape, rectangular in plan view, while at its lower part it comprises a bottom wall consisting of two sectors of cylinders of a circular cross section, having parallel axes, said cylinders partially interpenetrating one into the other and which at the central lower part are connected to a longitudinal channel, semicircular in cross section, into which a discharge screw operates, said tank being intermittently fed by two superimposed kneading tanks.

[0006] The tank has a form symmetric with respect to a longitudinal vertical plane X-X. In correspondance of axes Y-Y and Z-Z of the respective cylindrical sectors, the tank is provided with two longitudinal shafts, each respectively connected to a transmission assembly, adapted to cause said two shafts to rotate contemporaneously in opposite directions.

[0007] One of said shafts supports pairs of helicoidal blade lenghts, radially extending nearly up to'the tank walls, said blade lenghts having opposite rotation directions and being spaced apart from each other so that other pairs of blade lenghts can operate in interlacing condition therebetween, which are mounted about the other rotating shaft, said helicoidal blade lenghts having respectively an opposite winding arrangement as compared with that of the blade lenghts mounted on the first shaft. The lenghts of helicoidal blades of the first rotating shaft are designed to act along a work surface shaped as a sector of a cylinder of a circular cross section, said cylinder sector having an angular amplitude lightly lesser than 180⁰ and identically the blade lenghts of the second shaft extend within an equal angle, but said blade lenghts are mounted so as to be able to act on the_' oily paste at alternating time periods, i.e. they are dephased with respect to the preceding ones, so that said helicoidal blade lengths alternatively press the oily paste towards the outside or towards the longitudinal center plane of the tank as well as to and from the tank heads, thus causing an intimate squeezing and mixing of the paste, thus promoting the removal of the oil from the oily paste or pulp. Furthermore, by means of at least two radial arms, on the shafts which rotate in.opposite directions two longitudinal bars are respectively mounted, said. bars supporting a longitudinal comb-like member made of an elastomeric material, such as rubber, and which is provided with a row of teeth, duly spaced apart from each other. Each comb-like member slides in contact with the inner cylindrical surface of the respective lower side wall of the tank, said comb-like members tending to clean said surface portions, which are perforated.

[0008] The lower cylindrical tank portions are constructed as separated segments or subsectors of a cylindrical wall and are provided with longitudinal rows of slits extending in planes perpendicular to the axes of the shafts supporting the helicoidal blades and the comb-like members, these latter being provided with teeth duly spaced apart from each other by means of interposed slots so positioned as to respectively face said wall slits. Through said slits are designed to move to and from rows of vertical flat small blades carried by longitudinal bars, mounted on the outside of the tank, each bar being supported by pairs of radial arms which can reciprocate radially so as to cause said rows of small blades to enter from the outside through said slits so as to disobstruck and clean these latter from the paste inserted therein, while during their return stroke said small blades entrain together the oil towards the outer space, where the oil drips down under the effect of the force of gravity.

[0009] The small blades and the wall slits are so mutually positioned that, during the sliding of each comb-like member provided with teeth, said small blades can enter into the slots comprised between each pair of adjacent teeth of the comb-like member so as to clean the respective tooth slots, thus maintaining the elasticity of the respective comb-like member.

[0010] The radial arms mounted on .the outside of each tank head and which are designed to support and reciprocate radially each assembly of small blades, are actuated respectively by a respective came device designed to cause that one of the blade assemblies, in turn, performs radial reciprocating strokes according to a predetermined sequence with respect to those of the adjacent blades series.

[0011] The improved extractor of the invention has a higher yield as compared with those of the known machines and it permits to treat greater amounts of oily paste with a remarkably increased yield per hour.

[0012] These and other characteristics and advantages of the present invention will be better understood from the following description of an embodiment of said invention, reference being made to the accompanying drawings, in which:

Fig. 1 shows a diagrammatic, partial perspective top view of the extractor tank, the other parts of the extractor being omitted;

Fig. 2 shows a detail of the vertical axial sectional view A-A of Fig. 3 of one of the two rotating units supporting the helicoidal blades and operating in the inside of the tank;

Fig. 3 shows a detail view of one of the heads of the tank, taken in the transversal plane B-B of Fig. 2;

Fig. 4 shows in a more detailed manner the detail of Fig. 3 of one of the guiding devices of two rows or series of small blades;

Fig. 5 is a perspective view of the inner end of one of the radial arms provided to actuate the device, shown in Fig. 4; and

Fig. 6 shows, in an exploded perspective partial view, one of cylindrical segments or sub-sectors of the tank, the device carrying two rows of small blades, and the comb-like member, in the position in which is placed a comb-like member on the left side of Fig. 1.

[0013] The tank extractor, which is object of the present invention, is advantageously employed in an extraction plant of the oil from oily seeds or fruits, as olives and the like, in order to perform the first extraction of the oil from the oily paste, said tank extractor being mounted underneath kneading or breaking machines which are fed by a mill unit of the olives conveyed therein through a feeding hopper.

[0014] Said extractor consists of a tank, substantially rectangular in a plan view, generally indicated 1; near one of the heads lt of said tank said kneading machines are mounted (not shown in the drawings, since they are of a well known type), said mechines feeding the oily paste into the extractor tank 1.

[0015] Said tank 1 at its upper part has longitudinal vertical walls la and has a shape which is symmetric with regard to the longitudinal vertical plane X-X. The lower part lb of the tank 1 consists of two walls each having the shape of a sector of a cylinder, circular in cross section, said cylinders have longitudinal axes Y-Y and Z-Z respectively, which are spaced apart from each other of a distance lesser than the radius of these cylinders so that the inner spaces defined by the two cylinders mutually interpenetrate themselves beyond the plane X-X.

[0016] The walls lb end at a certain distance from the plane X-X where they join to a longitudinal channel lc having substantially a semi-cylindrical shape and which houses a longitudinal shaft 2 carrying a longitudinal screw 2a. This channel at the end of the tank 1, opposite to that where said kneading machines are placed, is connected to a kneading-diluting tank, from which the treated paste deprived from the oil, by means of a pump, is conveyed to an extraction centrifugal machine (decanter), not shown, wherein a second extraction step is carried out.

[0017] The walls lb shaped in the form of sectors of circular cylinders, having the axes Y-Y and Z-Z respectively, are constituted of cylinder sub-sectors or lengths 3. Each sub-sector or length 3 is provided with two longitudinal rows of through slits 5, each slit extending in a plane perpendicular to the respective axis Y-Y and Z-Z; these slits 5 pass through the wall of the sub-sector or length 3, while through said slits 5 is designed to be discharged the oil that will be separated from the oily paste. At 10a and 10b are indicated two longitudinal shafts, the ends of which come out the heads It of the tank 1; said shafts are caused to rotate in opposite directions (as shown by arrows in Figures 1 and 3) by means of a transmission unit, not shown in the drawings.

[0018] On the shaft 10a, by means of radial support arms 13a, pairs of lengths of helicoidal blades lla are mounted, designed to work near the inner surface of the cylindrical wall lb, placed on the left hand in Figure 1. The two lengths lla of the respective blades of the respective pairs have opposite operative directions and extend through a cylindrical sector lesser than 180⁰, said blade lengths lla being spaced apart one from the other parallely to the axis Y-Y.

[0019] On the shaft lOb, at the right hand in Figure 1, by means of support arms 13b, lengths of helicoidal blades llb are mounted around the shaft 10b, in the space in which no blade lla is mounted on the shaft 10a.

[0020] Said blade lengths llb, in their turn, are wound in opposite operative directions, either with respect to one another and to the adjacent blade lengths lla. The blade lengths llb operate in a cylindric sector of an angular amplitude substantially equal, but dephased with respect to that in which the blade lengths lla operate. It results that in the zones in which the cylindrical operative spaces of the two rotors 10a, lla and 10b, llb interpenetrate to one another, said blades lla and llb operate in opposite directions with a suitable phase displacement so as to obtain a perfect squashing and the complete releasing of the oil from the oily paste, till the moment in which the discharge takes place and when said oil through an intermediate squeezing and diluting tank by means of a motor pump, is conveyed into an extraction centrifugal machine (decanter) for a second extraction step (not shown).

[0021] On the shaft 10a, by means of the radial arms 13a, is also supported a longitudinal bar 4a which carries, a comb-like member 7a extending towards the outside, and provided with teeth 28, said comb-like member being made of an elastomeric material, as rubber or the like, and being so dimensioned as to be able to slide by means of their teeth 18a in contact with the wall lb at the left hand of Figure 1. The teeth 28 are spaced apart from each other by slots so positioned as to present themselves just in aligned facing relationship with the slits 5a during the rotation of the shaft 10a. Identically radial arms 13b made integral with the shaft 10b carry -a bar 4b supporting a comb-like member 7b provided with teeth 28 arranged and proportioned as the preceding described ones.

[0022] 6 generally indicates a device associated to each wall sub-sectors or length 3. Each device 6 comprises two radial arms 14a or 14b supporting longitudinal bar 8a or 8b, each of which, in this embodiment, supports two pluralities of small blades 9, each blade being so dimensioned and arranged as to be able to enter one split 5a or 5b or to come out therefrom as a result of the reciprocating strokes of the pairs of radial arms 14a or 14b, which are arranged out of the heads lt of the tank, in a radial disposition -with respect to the respective axis Y-Y or Z-Z of the shafts 10a or lOb. To each of the end portions of the shaft 10a or lOb, coming out the tank (Figure 3), and excentric disc 15a (15b) is fixedly connected, each disc 15a or 15b by means of a series of rolling rollers 16 can rotate in the inside of a peripheral ring 17a or 17b, to which, by means of hinge pins 18, the flattened end 14' or 14b' are articulated respectively of the arms 14a or 14b.

[0023] Therefore, as the pairs of excentric discs 15a-15a and 15b-15b rotate, the pairs of arms 14a or 14b in sequence cause the devices 6a, 6b to perform in sequence reciprocating strokes or radial translation, so that the pairs of rows of small blades 9a and 9b come into and out the slits 5a or 5b. During the entrance stroke, they disobstruct the slits 5a, 5b, and during the exit stroke, they entrain the oil towards the outside, owing to an adhesion effect, where said oil under the force of gravity, falls down into a suitable collecting container. It follows that by the use of the improved extractor of the invention the oily paste will be overworked more entirely as compared with what never has been obtained by means of the preceding systems and with a discharge step of the treated paste which does not require a protracted break phase and according to a very quick operative cycle.

Claims

1. An extractor of oil from an oily seed or fruit paste,in particular olive paste, comprising a treatment tank (1), rectangular in a plan view, in to which two rotors (10a, lla and lOb, llb) operate having helicoidal blades (lla, llb) arranged in interlacing positions, said tank having upper vertical side walls (la) and lower walls (lb), each having the shape of a sector of a circular cylinder, the cylinders having longitudinal axes (Y-Y) and (Z-Z), spaced apart one from the other of a value lesser than the radius thereof, characterized by the fact that between the walls (lb) each having a cylindrical shape, at the bottom of the tank (1) a substantially semi-cylindrical channel (lc) is interposed, into which rotates a screw (2a, 2) and which is provided with a discharge orifice of the treated oily paste, within said tank (1) being operatively mounted two rotors (10a, lla and lOb, llb) which rotate in opposite directions around the respective axes (Y-Y) and (Z-Z), said rotors carrying pairs of helicoidal blades (lla-lla and llb-llb), said blades operating near the inner surface of the respective wall (lb) of the tank (1) and having an opposite winding direction and being so angularly positioned that the pairs of blades, (llb) mounted on the shaft (lOb), reach the interlacing space or zone in times, different from those during which operate the pairs of blades (llb), the blades (lla) being so spaced apart from each other so as to permit to the pairs of blades (llb) to operate in the zone which is not traversed by the blades (lla), on the shafts (10a, 10b) which carry blades (lla) and (llb) in only a sector space of an angular amplitude lesser than 180°, by means of radial arms (13a and 13b) 5are mounted comb-like members (7a and 7b) so proportionated that each member can slide on the inner surface of the cylindrical walls (lb), which is provided with longitudinal rows of slits (5a and 5b), while at the outside of the wall (lb) of the tank (1) are operative devices (6a, 6b) associated with means adapted to impart a reciprocating radial motion to said devices, each supporting at least one plurality of small blades (9a, 9b) so arranged and positioned as to be able to enter and slide along the slits (5a, 5b) and which during the entrance stroke disobstruct the slits (5a, 5b) and during the return stroke entrain together the oil towards the outside, owing to an adhesion effect, where the oil, under the effect of the force of gravity, falls down into a suitable container.

2. An extractor according to claim 1, wherein the walls (lb), each having the shape of a cylindrical sector (lb) of the tank (1), are realized in longitudinal cylindric sub-sectors or lengths (3) of the cylindrical sector (lb), each of said lengths (3) having two longitudinal series of through slits (5a, 5b) extending in planes perpendicular to the respective rotor axis, each device (6a, 6b), which operates at the outside of the tank (1) comprising a pair of radial arms (14a, 14b) carrying longitudinal bars (8a, 8b) supporting two rows of small blades (5a, 5b), said arms (14a, 14b) being articulated at their other ends by means on hinge pins (18) to a ring (17) in the inside of which can rotate an excentric disc (15a, 15b) with the interposition of rolling rollers (16), said pair of excentric discs being keyed on the outer ends of the rotor shafts (10a, 10b).

3. An extractor according to claim 1, wherein each comb-like member (7a and 7b) is made of hardened rubber and is supported by a bar (4a, 4b) by means of radial arms (13a, 13b), said comb-like members being mounted in angularly dephased positions on the respective rotors (10a, lla and 10b, llb) and the teeth (28) thereof being so proportionated that the respective slots slide along the corresponding annular wall bands in which the slits (5a, 5b) are so arranged that at the end of the forward strokes of the series of small blades (5a, 5b), these latter can enter also said slots.

4. An extractor according to claim 1, wherein said extractor allows to release the oil up to the last operative extraction instant.

5. An extractor according to claim 1, wherein the two bars carrying the comb-like members made of rubber operate in synchronism, thus hightly promoting the extraction process.

Drawing