WO1990003116A1

WO1990003116A1 - A method of separating objects, in particular dividing shrimps up into heads and bodies, and an apparatus for use in carrying out the method

Info

Publication number: WO1990003116A1
Application number: PCT/DK1989/000220
Authority: WO
Inventors: Henrik Hjelmsmark; Morten F. Lerche; Erik Andersen
Original assignee: Cabinplant Development A/S
Priority date: 1988-09-20
Filing date: 1989-09-19
Publication date: 1990-04-05
Also published as: DK522988A; AU4336189A; DK522988D0

Abstract

Shrimps may be passed down into a severing device (5) which as a unit may effect such a reciprocating movement that rod members accommodated in the device sever the shrimp into a roller-like head portion (20) and a disc-like body portion (21). In a separator device (6) in which a number of radially directed roller planes consisting of a big inner cylinder (29) and a number of smaller cylinders (30) are disposed in plate members (24), the roller-like parts are separated from the disc-like parts. All the cylinders are rotated in the same direction of rotation, thereby inducing the roller-like parts to deposit between two cylinders and rotate, while the disc-like parts are being carried away in the radial direction when the roller plane is in an angle interval (α, β) about the horizontal plane. When the roller plane of a motor (28) is rotated past the angle α the roller-like heads will slide radially outwards. A dividing plate (44) ensures that shrimp tails (21) are guided separately away.

Description

A method of separating objects, in particular dividing shrimps up into heads and bodies, and an apparatus for use in carrying out the method.

The invention relates to a method of severing objects, especially shrimps, into a roller-like part, in particular shrimp heads, and a disc-like part, in particular shrimp bodies, followed by a separating of the roller-like parts from the disc-like parts, the severing being effected by subjecting the objects in a severing device to impacts from reciprocating rod members.

The purpose of mechanically peeling of shrimps, including e.g. Pandalus Borealis, Pandalus Montagui, Crangon Crangon, Euphausia Superba, Peneaus Indicus and Metapeneus Ensis, is to separate the edible muscle meat of the shrimp, amounting to about 30% of the total weight of the shrimp, from the shrimp shell, shrimp head and entrails.

GE patent No. 1 179 303 discloses a method of the above mentioned type according to which the shrimp is separated into a head portion and a body portion in a severing device having a stationary plate with projecting rods and an opposite plate with projecting blades positioned between the rods. The severing is effected in that the blades carrying plate is moved reciprocabiy in relation to the stationary plate, thereby imparting impact and bending action to the shrimps supplied to the device so that the comparatively weak joint between the head and body will be broken. After washing with water the severed shrimps are discharged on a conveyor belt for manually separating the bodies from the heads. In practice a mechanical peeling of the bodies is, however, frequently effected prior to separating them from the heads.

Due to the relatively high price of shrimp meat even a smaller amount of injured or discarded shrimp bodies will make this mode of processing uneconomical. It is therefore a disadvantage of the above mentioned severing device that some of the bodies are broken or subjected to damaging impact when getting jammed between the blades and the rods.

When heads and bodies are supplied to a peeling apparatus a considerable portion of the entrails will be knocked out of the heads concurrently with deshelling and peeling the bodies. During the subsequent clean-washing of the deshelled bodies the entrails will be dissolved in the wash water. Due to environmental precautions, the water used for the desheiling must be purified of biological material, which is rather expensive. The water pollution may be considerably reduced if the heads severed from the bodies were carried away prior to desheiling the bodies. It has shown difficult, however, to reach a suitable method of separation which does not entail loss of shrimp bodies.

The method according to the invention is characterized in that the severing device through which the objects are passed is moved reciprocably as a unit so as to divide the objects into two parts, and in that the said parts are transferred to a separator device comprising a roller plane consisting of at least two cylinders rotating in the same direction about their longitudinal axis so that the disc-like parts are conveyed in one direction and the roller-like parts are carried away in another direction.

When severed shrimp heads and tails are disposed on at least two rollers it has surprisingly turned out according to the invention that the head which is a kind of elongated roller will deposit in the prismshaped gap between the cylinders and here effect a rotating movement about its longitudinal axis, whereas the disc-like tail will be caught by the roller and conveyed transversely of the longitudinal axis thereof. By a suitable arrangement and operation of the cylinders the separation may be carried out in such a manner that mainly all heads are removed without incurring any loss of tails.

The loss of shrimp tails caused by injury may, moreover, be reduced by moving the entire severing device as a unity so that the rods members of the two lateral plates are stationary relative to each other, thereby eliminating damage to shrimp bodies in unison with still severing the shrimps in the head joint. This is due to the fact that by the rod members the shrimps are solely subjected to impact action.

When using the method according to the invention in connection with an apparatus for deheading shrimps there is provided such a severing and separating-away of heads from bodies that up to 60% of the shrimp material inappropriate for human consumption is carried away before reaching the peeling apparatus, thereby obtaining, firstly, a drastic reduction of the water pollution while desheiling and of the concomitant need for water purification and, secondly, an increased capacity of the peeling apparatus because only the tails have to be processed and, thirdly, the possibility of making use of the discarded shrimp material for another purpose. The discarded shrimp material contains the major part of the water-soluble entrails and the remaining material, mainly consisting of shell remains, may largely be removed from the wash water by mechanical purification.

The invention also relates to a severing device for carrying out the method and the device differs from the device disclosed in the GB reference in that the rod members are bars interconnecting the faces and that the severing device effects the reciprocating movement as a unit. Moreover, the invention relates to a separator unit for carrying out the method. An embodiment of the separator unit is characterized in that it includes at least two parallel cylinders for rotation in the same direction about a respective longitudinal axis forming an angle to the horizontal plane and in that the diameter of the cylinders is adapted so to the cross- sectional dimension of the roller-like portions that said latter portions will be made to rotate about their longitudinal axes by two adjacent cylinders. Due to the inclined position of the cylinders the heads rolling between the cylinders will slide along the cylinders and out over the end edge thereof. From a structural point of view this embodiment is extremely simple and thus inexpensive and it may be varied in size by arranging a larger or smaller number of cylinders side by side. Due to the fact that the heads which have not started to slide along the cylinders might obstruct the passage of the succeeding bodies or heads, the capacity is, however, limited.

If the size of the shrimps to be separated varies much, it is advantageous to make use of another embodiment of the separator device which according to the invention is provided with two frustoconical cylinders forming an angle to the horizontal plane and being positioned close to each other, said cylinders being intended to rotate in the same direction about a respective longitudinal axis, the largest diameter of said cylinders being substantially larger than both the roller-like part and the disc-like part.

A further embodiment of the separator device for carrying out the method according to the invention includes at least one cylinder plane consisting of a plurality of parallel circular-cylindrical cylinders bedded in supporting means so that the cylinders are positioned close to each other and are capable of rotating in the same direction about their respective longitudinal axes positioned in a common plane, the supporting means being pivotal about a horizontal centre axis extending parallel to the longitudinal axis of the cylinders. This device may be designed to an extremely large capacity and is therefore particularly advantageous for industrial peeling of shrimps. In operation, an amount of severed shrimps is poured down on the roller plane while this is being pivoted from vertical to horizontal. Due to the fact that the cylinders cause the heads to roll while conveying away the tails, the desired separation will be effected while the roller plane is occupying angular positions before and a little after the horizontal plane. Not until the roller plane is at a determined downwards angle in relation to horizontal, the gravitational force will actuate the heads to being conveyed away transversely of the cylinders.

A particularly preferred further development of the latter embodiment is characterized in that the supporting means are plate end members, that there are several roller planes extending in parallel with each an individual radius from the centre axis and being uniformly distributed thereabout, that the disc- and roller-like portions may be supplied from above downwards between the roller planes, and in that radially outside the roller planes there is provided a stationary dividing plate the internal edge of which is positioned at a determined height in relation to the centre axis. The roller planes divide the gap between the plate members into "receptacles" for the heads and tails coming from above, and due to the turning of the plate end members one receptacle after the other will turn upwards for filling. The bodies will be discharged above the dividing plate and the heads below the dividing plate. This provides for obtaining an extremely large capacity of the device which further occupies such a small volume that it may be installed in a simple manner in existing peeling apparatuses together with the severing device according to the invention.

The invention will now be explained in further detail with reference to the schematical drawings, in which

Fig. 1 is a side view of a shrimp peeling apparatus with a severing and a separator device according to the invention,

Fig. 2 is a perspective view to illustrate the principle of the severing device in Fig. 1,

Fig. 3 is an embodiment of a separator device, Fig. 4 is a perspective view illustrating a second embodiment of a severing device,

Fig. 5 is a partially sectional side view of the device in Fig. 4,

Fig. 6 is an illustration of a part of a roller drive of the device in Fig. 4,

Fig. 7 is a fractured cross-section of the device in Fig. 4, and

Fig. 8 is a third embodiment of a separator device according to the invention.

The shrimp peeling apparatus illustrated in Fig. 1 includes a feedtank 1 in which the raw shrimps that may either be fresh or separately frozen or block- frozen thawn-up shrimps are dropped into a water bath at the arrow 2. The water bath and a plate, not shown, which at a distance above the upper run of a conveyor 3 is transverse thereto, dispenses the shrimps in a uniform layer on the conveyor that passes the shrimps up into a steam cooker 4 in which they are boiled for a period dependent on the feeding rate of the conveyor. The boiled shrimps drop into the severing device 5 in which the heads are severed from the tails, following which the shrimps thus severed drop into a separator device 6 having a coarse separator 7 and a fine separator 8 obliquely positioned therebelow, said two separators corresponding each to the device described later on with reference to Figs 4 to 7.

The heads are diverted from the separator at the arrow 9, while the tails at the arrow 10 are transferred to a peeling device removing the shell from the tails. The deshelled and edible shrimp tails leave the apparatus at 12 and may for instance be frozen, water-glazed and, packed in portions. The wash water from the peeling process is diverted for purification at 13. The illustrated apparatus may have a shrimp capacity of about 600 kg/h., the shrimp size amounting e.g. to 2 g each, i.e. about 83 pieces/sec. are being processed. The size of the shrimps may, however, fluctuate between 1 g each and 12 g each.

Fig. 2 illustrates the severing device 5 constructed of two parallel plates 14 that are separated from each other and connected through rod members in the form of bars 15 having a cross- sectional dimension that is considerably smaller than the thickness of the shrimp. The device is normally closed at the short end faces and the whole shrimps are supplied at the arrow 16, and the shrimps severed into heads and tails are discharged at the arrows 17. The plates form an angle α, preferably of 90°, to the horizontal plane and the entire device is driven by a drive, not shown, in a reciprocating movement according to the arrow 18. The bars 15 impinge the shrimps with a force sufficiently great to break the joint between the head and the tail but too small to injure the meat in the tails. In an advantageous embodiment the distance between the plates 14 is 60 mm and the bars that are circular with a diameter of 3 mm are positioned in an asymmetrical pattern at a mutual distance of about 20 mm. The reciprocating movement has an amplitude of 100 mm and a frequency of 3 to 10 stroke/sec, preferably 4.5 stroke/sec. It is obvious that the above mentioned impinging force can be adjusted in accordance with the size, shell thickness etc. of the shrimps to be severed by simply regulating the frequency and the stroke length of the reciprocating movement.

The drive, not shown, for effecting the reciprocating movement may include a rod which at one end is pivotally connected with the plates 14 and at the other end is journalled eccentrically on a wheel that can be turned by an electrical motor at adjustable speed. The plates 14 may further be supported by a slide guide or a slide bearing that is supportably connected with the frame of the peeling apparatus.

Fig. 3 illustrates a roller plane consisting of identical circular-cylindrical cylinders 19 positioned in parallel and side by side at a quite short mutual distance. The cylinders are intended to rotate in the same direction of rotation and have a diameter that is larger than the shrimp heads to be sorted out. Heads 20 and bodies 21 are supplied at the upper corner of the roller plane at 22 and the heads will deposit between the cylinders and due the friction against the cylinders they are forced to rotate, thereby being caught in the gap between the cylinders. In view of the fact that the longitudinal axes of the cylinders form an angle α to the horizontal plane, the heads will by gravitation be pulled along the gap between the cylinders and drop down at 23. The number of cylinders is adapted so that mainly all of the heads manage to orient their longitudinal axis along the longitudinal axis of the cylinders so as to be caught in a gap between the cylinders. Due to their crescentshaped form the bodies 21 behave as discs which have no natural axis of rotation. In the direction A they will therefore be carried along with the cylinders operating as a roller conveyor. It is within the possibilities of a person skilled in the art to construct a support and a drive for the cylinders 19. The cylinders may e.g. at their ends be journalled in plate members positioned transverse to the rotational axes of the cylinders. At the discharge end of the cylinders the upper edge of the plate member should be formed with cut outs corresponding to the cylinder gaps so that the discharge of the heads is unobstructed. At the feeding end the cylinder could be provided each with a drive wheel connected with a common drive. The drive of the cylinders could be effected in a manner similar to the one to be described with reference to Figs 6 and 7. The plate members carrying the cylinders may be supported by a frame standing on the floor.

The embodiment illustrated in Figs 4 to 7 of the separator device 6 includes a number of roller planes, in the illustrated case eight, which are located in stelliform between two circular plate end members 24 supported by a central, horizontal pivot shaft 26 journalled in a frame 25 which over a transmission 27 may be driven by a motor 28.

Each roller plane comprises a large inner cylinder 29 and a number of smaller outer cylinders 30 positioned side by side radially from the cylinder 29. The cylinders 29 are positioned at a uniform radial distance from the shaft 26 and at such a short distance from each other that a shrimp is prevented from passing between the cylinder gap. Between them, the cylinder planes thus form prism-shaped receptacles for receiving the disc- and roller-shaped objects, preferably shrimp heads and tails, that discharge through the outlet of the device 5 positioned above. All cylinders as well as the shaft 26 with end members 24 are driven in the same rotational direction as described in the following with reference to Figs 6 and 7, observing that the side of Fig. 7 facing the drive is a sectional view along the dot-and-dash line VII-VII in Fig. 6.

The shaft 26 may over a toothed belt 27 and a pulley 31 be driven at variable speed of rotation that is adaptable to the supplied amount of shrimps, thereby pulling the end members 24 which through hubs 32 are firmly connected with the shaft. Another toothed belt 33 which may either be driven by the motor 28 or by an independent drive source drives through a pulley 34 a centre gear-wheel 36 that is coaxial with the shaft 26 and is disposed on a bearing housing 35, said gear-wheel driving through idle wheels 37 journalled in the end member, cylinder wheels 38 firmly connected with the inner cylinders 29. The gear-wheels 38 pull through idle wheels 39 journalled in the end members a cylinder wheel 40 firmly connected with each cylinder 30, wherefrom it will appear that all of the rollers may be driven in the same direction. In respect of clearness only the vertical row of gear-wheels illustrated in Fig. 6 is complete.

For the purpose of saving materials the big cylinders 29 may, as it will appear from Fig. 7, be designed as a tube 41 which is closed by bottoms 42 which for instance through glueing are firmly connected with trunnions 43 to be journalled in the end members 24, whereas the small cylinders normally will be manufactured as solid cylinders.

Referring to Fig. 5 the principle of the separation will now be described in more detail. As mentioned, the shrimp parts fall down into the receptacles. During the continuous rotation the cylinders 29 orient a major portion of the heads 20 so that their longitudinal axis conforms with the longitudinal axis of the cylinders, thereby largely facilitating the separation when the shrimp parts slide out on to the roller plane proper which is constituted by the cylinders 30. The removal of bodies 21 starts when the roller plane passes the angular position marked at β , which depends on the rotational speed of the cylinders and may for instance amount to 15º above the horizontal plane, because the radially outwards directed effect of conveyance of the cylinders here overcome the gravitational pull on the bodies. At this angularly turning position the heads will roll largely stationarily in a gap between the cylinders but a certain "stirring" is, however, effected, thereby advancing new bodies on the roller plane. Not until the roller plane has been rotated to an angular position γ that may for instance be 5° under the horizontal plane, the heads start moving radially outwards.

A dividing plate 44 whose inner edge is positioned immediately radially outside the cylinders 30 in a position corresponding to the angle γ takes care of carrying away the bodies 21, and the heads 20 fall away beneath the dividing plate.

In view of the fact that the economy of shrimp peeling is ruined if only a few percent of the bodies are guided away together with the heads, it may be advantageous in case of large flow amounts to provide a fine sorting by arranging two separator devices one after the other so that the second device is fed from the outlet of heads from the first device.

The number of roller planes in the device 6 is adapted to the desired separator capacity and the small cylinders 30 may also be arranged parallel displaced in relation to the illustrated embodiment, their outer face being then aligned along a tangential line to the cylinder 29.

In a preferred embodiment there are four cylinders 30 with a diameter of 18 mm in each roller plane and sixteen roller planes in a device 6. Here, the cylinders 30 rotate at a number of revolutions of about 540 rpm.

The severing device 5 illustrated in Figs 4 and 5 may in a manner similar to the one mentioned with reference to Figs 1 and 2 be supported by a slide bearing that is supportably connected with the frame 25 and may be provided with a suitable drive of the mentioned kind.

In the third embodiment of the separator device illustrated in Fig. 8 two inclined conical cylinders 45 are used as the roller plane. This design stems from the recognition of the advantageous feature that the heads are compelled to roll before the bodies are carried away by the cylinders which takes place when the bodies have such a size in relation to the cylinder diameter that the frictional action originating from the cylinders and acting in the direction of rotation overcomes the gravitational force on the bodies. The bodies and the heads are supplied at the arrow 46 where the cylinders have a large diameter in relation to the severed shrimp pieces, and the bodies will in dependence on their size for instance be conducted away in the direction of the arrow 47 while the rotating heads will slide off the cylinders at 48. This design is particularly advantageous in the separation of shrimp parts of much varying size and it offers a high degree of security against loss of bodies. The cylinders 45 can be supported and driven in the same manner as mentioned with reference to Fig. 3.

The severing device according to the invention can be made with bars having a cross-sectional dimension varying from the above mentioned, as long as the dimension does not get substantially larger than the cross-sectional dimension of the shrimps .

The separator device according to the invention may also be used as an independent unit, e.g. to separ ate mussels from shells, whole shrimps from fish or fish from fish, provided it is merely a question of separating disc-like objects from roller-like objects.

It is obvious that the separating effect of the cylinders in the different embodiments of the separator device according to the invention depends on frictional conditions between the object to be separated and the cylinders. These frictional conditions may be controlled by choosing an appropriate diameter, positioning, surface roughness, rotational speed etc. of the cylinders.

Claims

P A T E N T C L A I M S

1. A method of severing objects, especially shrimps, into a roller-like part, in particular shrimp heads (20), and a disc-like part, in particular shrimp bodies (21), followed by a separating of the rollerlike parts from the disc-like parts, the severing being effected by subjecting the objects in a severing device to impacts from reciprocating rod members (15), characterized in that the severing device (5) through which the objects are passed is moved reciprocably as a unit so as to divide the objects into two parts, and in that the said parts are transferred to a separator device comprising a roller plane consisting of at least two cylinders (19; 30; 45} rotating in the same direction about their longitudinal axis so that the disc-like parts are conveyed in one direction (A; 10; 47) and the roller-like parts are carried away in another direction

( 23 ; 9; 48) .

2. A method as claimed in claim 1, characterized in that the disc-like parts are conveyed in a direction transversely of the longitudinal axis of the cylinders (19;45), while the roller-like parts are carried off substantially in the direction of the longitudinal axes.

3. A method as claimed in claim 1, characterized in that the roller plane is rotated about a substantially horizontal axis extending in parallel to the axes of the cylinders (30), and in that the disc-like parts are conveyed transversely of the longitudinal axes of the cylinders, when the roller plane is in a determined angular interval ( β , γ ) in relation to the horizontal plane, whereas the roller-like parts are guided away transversely of the longitudinal axes of the cylinders (30), when the roller plane has passed the determined angular interval.

4. A severing device for carrying out the method according to claim 1 and including a housing with two parallel and plate-like restricting faces supporting rod members and capable of effecting a reciprocating movement (18) and an inlet opening and an outlet opening passing the objects to (16) and from (17), respectively, the gap between the faces, characterized in that the rod members are bars (15) interconnecting the faces (14) and that the severing device effects the reciprocating movement as a unit.

5. A separator device for use in carrying out the method according to claim 2, characterized in that it includes at least two parallel cylinders (19; 45) for rotation in the same direction about a respective longitudinal axis forming an angle (β) to the horizontal plane and in that the diameter of the cylinders is adapted to the cross-sectional dimension of the roller-like parts (20) so that said latter parts are induced to rotate about their longitudinal axes by two adjacent cylinders (19;45).

6. A separator device for use in carrying out the method according to claim 2, characterized in that it includes two frustoconical cylinders (45) forming an angle to the horizontal plane and being positioned close to each other, said cylinders being intended to rotate in the same direction about a respective longitudinal axis, the largest diameter of said cylinders being substantial ly larger than the roller-like ( 20 ) as well as the disc-like part.

7. A separator device for use in carrying out the method according to claim 3, characterized in that it includes at least one roller plane consisting of a plurality of parallel circular-cylindrical cylinders (30) journalled in supporting means (24) so that the cylinders are positioned close to each other and are capable of rotating in the same direction about their respective longitudinal axes positioned in a common plane, the supporting means being pivotal about a hori zontal centre axis extending parallel to the longitudinal axis of the cylinders.

8. A device as claimed in claim 7, characterized in that the supporting means are plate end members (24), that there are several roller planes extending in parallel with each an individual radius from the centre axis and being uniformly distributed thereabout, that the disc- and roller-like parts may be supplied from above downwards between the roller planes, and in that radially outside the roller planes there is provided a stationary dividing plate (44) the internal edge of which is positioned at a determined height in relation to the centre axis.

9. A device as claimed in claim 8, characterized in that it includes two sets of plate end members (24) with associated roller planes, the first set of which being supplied with disc- and roller-like parts and the second set being positioned obliquely beneath the first set and being supplied with coarsely separated parts therefrom.

ABSTRACT

Shrimps may be passed down into a severing device (5) which as a unit may effect such a reciprocating movement that rod members accommodated in the device sever the shrimp into a roller like head portion (20) and a disc-like body portion (21).

In a separator device (6) in which a number of radially directed roller planes consisting of a big inner cylinder (29) and a number of smaller cylinders (30) are disposed in plate members (24), the roller- like parts are separated from the disc-like parts. All the cylinders are rotated in the same direction of rotation, thereby inducing the roller-like parts to deposit between two cylinders and rotate, while the disc-like parts are being carried away in the radial direction when the roller plane is in an angle interval (α,β) about the horizontal plane. When the roller plane of a motor (28) is rotated past the angle a the roller- like heads will slide radially outwards. A dividing plate (44) ensures that shrimp tails (21) are guided separately away.

(Fig. 5).