EP0252025B1

EP0252025B1 - An improved extractor of oil from oily seed or fruit pastes and the like

Info

Publication number: EP0252025B1
Application number: EP87830230A
Authority: EP
Inventors: Ezio Rapanelli
Original assignee: RAPANELLI FIORAVANTE SpA
Current assignee: RAPANELLI FIORAVANTE SpA
Priority date: 1986-06-24
Filing date: 1987-06-19
Publication date: 1991-01-02
Anticipated expiration: 2007-06-19
Also published as: EP0252025A2; GR3001661T3; ES2020301B3; ATE59601T1; EP0252025A3; IT1191971B; DE3766895D1; IT8648181A0

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 DEG , 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 (1b). 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

The present invention concerns a tank extractor for the separation of the oil or juice from oily seed or fruit pastes, more in particular, from olive paste, 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.
Extractors for the separation of the oil from oily pastes and hte 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. The large part of said known apparatuses are designed to treat the paste in batches so that, at predetermined time intervals, the apparatuses have to be stopped and the treated paste has to be discharged, in general, by overturning the tank.
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.
LU-A-51045 is also known that concerns an apparatus in which a continuous process is applied for the separation of oil from oil palm fruit pulp, subjecting said oil palm pulp to a pressing method in the inside of the tubular treating chamber along which said pulp is caused to be pushed forwards.
Said chamber is defined by a tubular wall open at its ends and having the shape of two partial circular cylinder sectors each having an angular amplitude slightly higher than 180° so as to have a generally oval cross section. The cylinder sectors have parallel axes, spaced apart from one another less than the radius of said cylinders. Along said axes parallel shafts, having interfitting helicoid surfaces are mounted, which rotate in opposite directions.
Holes or slits are arranged through the treatment chamber wall for the escaping of the oil expressed from the oily pulp by passage over helicoid pressing surfaces. Said separation system of the oil from the oily pulp, under the effect of a high pressure, has the disadvantage that this system causes an undesired overheating of the oil.
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.
At the upper part the tank is open; this latter has a parallelopiped shape, rectangular in plan view, while at its lower part it comprises a bottom wall consisting of two sections of cylinders of a circular cross section, having parallel axes, said cylinders partially interpenetrating one into the other and at the central lower part they 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.
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.
One of said shafts supports pairs of helicoidal blade lengths, radially extending nearly up to the tank walls, said blade lengths having opposite rotation directions and being spaced apart from each other so that other pairs of blade lengths can operate in interlacing condition therebetween, which are mounted about the other rotating shafts, said helicoidal blade lengths having respectively an opposite winding arrangement as compared with that of the blade lengths mounted on the first shaft. The lengths of helicoidal blades of the first rotating shaft are designed to act along the respective work surface shaped as a sector of a cylinder of a circular cross section, said cylinder sector having an angular amplitude lightly lesser than 180° and identically the blade lengths of the second shaft extend within an equal angle, but said blade lengths 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. 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 baldes 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.
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.
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.
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.
These and other 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 detailed 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 of sub-sectors of the tank bottom, 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.

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.
Said extractor consists of a tank, substantially rectangular in a plan view, generally indicated 1; near one of the heads 1t of said tank, kneading machines are mounted (not shown in the drawings, since they are of a well known type), said machines feeding the oily paste into the extractor tank 1.
Said tank 1 at its upper part has longitudinal vertical walls 1a and has a shape which is symmetric with regard to the longitudinal vertical plane X-X. The lower part 1 b 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.
The walls 1b which end at a certain distance from the plane X-X, are connected to a longitudinal channal 1c having a substantially semi-cylindrical shape and which houses a longitudinal shaft 2 carrying a longitudinal screw 2a. This channel 1c 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 a part of 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.
The walls 1b, 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, since 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 1t 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 motion transmission unit, not shown in the drawings.
On the shaft 10a, by means of radial support arms 13a, pairs of lengths of helicoidal blades 11 a are mounted, designed to work near the inner surface of the cylindrical wall 1b, placed on the left hand in Figure 1. The two lengths 11 a of the respective blades of the respective pairs have opposite operative directions and extend through a cylindrical sector lesser than 180°, said blade lengths 11 a being spaced apart one from the other parallely to the axis Y-Y.
On the shaft 10b, at the right hand in Figure 1, by means of support arms 13b, lengths of helicoidal blades 11 bare mounted around the shaft 10b, in the space in which no blade 11a is mounted on the shaft 10a.
Said blade lengths 11 b, in their turn, are wound in opposite operative directions, either with respect to one another and to the adjacent blade lengths 11 a. The blade lengths 11 b operate in a cylindric sector of an angular amplitude substantially equal, but dephased with respect to that in which the blade lengths 11 a operate. It results that in the zones in which the cylindrical operative spaces of the two rotors 10a, 11 a and 10b, 11 b interpenetrate to one another, said blades 11a and 11 operate in opposite directions with a suitable phase displacement so as to obtain a perfect squashing and the nearly complete releasing of the oil from the oily paste, till the moment in which the discharge takes place and when said paste 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).
On the shaft 10a, by means of a radial arms 13a, a longitudinal bar 4a is also supported which carries, a comb-like member 7a extending towards the outside, and provided with teeth 28, (Fig. 6), 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 28 in contact with the wall 1 b 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 ends of the slits 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 one.
6 generally indicates a device associated to each wall sub-sectors or length 3. Each device 6 comprises two parallel 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 1t of the tank, in a radial disposition with respect to the respective axis Y-Y or Z-Z of the shaft 10a or 10b. To each of the end portions of the shaft 10a or 10b, 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 ends 14a' or 14b' of the arms 14a or 14b are articulated respectively.
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 or juice from oily seed or fruit pastes, in particular olive paste, comprising a treatment tank (1), rectangular in a plan view and having upper vertical side walls (1a) and lower walls (1b) each having the shape of a sector of a circular cylinder of an angular amplitude less than 180°, said cylindrical walls (1 b) having longitudinal parallel axes (Y-Y and Z-Z) spaced apart from each other of a distance less than the radius thereof, and being provided with longitudinal series of lists (5a, 5b), associated with devices (6a, 6b) apt to maintain periodically said slits disob- structed and to promote the oil discharge, characterized by the fact that between said cylindrical lower walls (1 b) and near the vertical longitudinal center plane (X-X) of the tank (1) a substantially semi-cylindrical longitudinal channel (1c) is arranged in the bottom of the tank, into which a screw (2, 2a) rotates, and which is provided with a discharge orifice for the treated oily paste, into said tank (1) two rotors being operatively mounted which rotate in opposite directions about the respective axes (Y-Y and Z-Z), said rotors comprising parallel shafts (10a, 10b) respectively, which support pairs of helicoidal blades (11a-11a and 11b-11b respectively), the peripheral edges of said blades operating just near the inner surface of the respective walls (1 b) of the tank, the pairs of blades mounted about each shaft (10a, 10b) having opposite winding directions and being so angularly dephased that the pairs of blades (11a) mounted on the shaft (10a) pass through the operative inner interlacing space or zone of the tank (1) during time intervals different from those, during which the pairs of blades (11 b) pass which are mounted on the shaft (10b), the blades (11a) being so spaced along the shaft (10a) as to permit the pairs of blades (11b) mounted on the shaft (10b) to operate in zones which are not traversed by the blades (11 a) and the helicoidal blades (11 a and 11b) extend through an angle less than 180° about their respective supporting shafts (10a-10b), while a comb-like member (7a or 7b), carried by radial arms (13a or 13b), is further mounted on each respective shaft (10a and 10b), said comb-like members being so proportionated and positioned that each member (7a and 7b) can slide along the inner surface of cylindrical walls (1b), with said longitudinal rows of slits (5a, 5b) and co-operating devices (6a, 6b), associated with means (14a, 14b) apt to impart radial reciprocating movements to said devices (6a, 6b), each device (6a, 6b) comprising an outer longitudinal bar (8) supporting at least one plurality of small blades (9) so shaped, arranged and spaced apart from each other as to be able to enter the, and to slide through slits (5a, 5b) so that during the entrance stroke thereof, they can disobstruct said slits (5a, 5b), while during the return stroke they entrain oil towards the outside, owing to an adhesive effect, oil, which under the force of gravity, falls down into a collecting container placed below.

2. An extractor according to claim 1, wherein the lower walls (1b), each having the shape of a cylindrical sector (1b) of the tank (1), are constituted of longitudinal cylindric sub-sectors or lengths (3) of each cylindrical sector (1b), each of said lengths (3) having two longitudinal series of through slits (5a, 5b) extending in planes perpendicular to the respective rotor axis (Y-Y, Z-Z), each device (6a, 6b), which operates at the outside of the tank (1), comprising a pair of radial arms (14a, 14b) carrying the longitudinal bars (8a, 8b) supporting two rows of small blades (9), said arms (14a, 14b) being articulated at their other ends by means of 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 respectively keyed on the ends of the rotor shafts (10a, 10b), projecting out of the vertical heads of the tank (1).

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, 11 a and 10b, 11b), while the teeth (28) thereof are so proportionated that the resepective slots between them slide along the corresponding annular wall bands in which the slits (5a, 5b) are arranged so that at the end of the forward strokes of the series of small blades (9), these latter can enter also said slots and be inserted between the slots of the teeth 28 of the comb-like member (7a or 7b).

4. An extractor according to claim 1, wherein the two bars (4a, 4b) carrying the comb-like members (7a, 7b) made of rubber operate in synchronism, thus hightly promoting the extraction process.