WO2002026045A1

WO2002026045A1 - Carcass cleaning devices and methods

Info

Publication number: WO2002026045A1
Application number: PCT/GB2001/002279
Authority: WO
Inventors: Nigel Sanders
Original assignee: Food Pro Systems Limited
Priority date: 2000-09-29
Filing date: 2001-05-18
Publication date: 2002-04-04
Also published as: GB0023980D0; NZ525447A; AU2001258600A1; EP1324664A1

Abstract

One embodiment provides a carcass cleaning system comprises: a vacuum source; a cleaning head (1), having walls (2, 4, 6) defining a vacuum chamber (8) in communication via a vacuum line with the vacuum source, the vacuum chamber (8) having an open vacuum mouth (10); and a pressurised cleaning fluid supply (30), which supplies said cleaning fluid via a fluid line (28) to one or more cleaning fluid outlets (26) within the vacuum chamber (8), the cleaning outlets (26) being directed to spray cleaning fluid towards the vacuum mouth (10); whereby the vacuum mouth (10) may in use be positioned adjacent or against a carcass (13) to allow sprayed cleaning fluid to contact the carcass and be removed under vacuum via the vacuum line. In a second embodiment, a cleaning head (101) comprises a vacuum chamber (108) having an open mouth (110) at a longitudinal end of the chamber; and a pressurised cleaning fluid supply supplies pressurised cleaning fluid to a plurality of cleaning fluid outlets (126) within the vacuum chamber (108), which fluid outlets are directed to release cleaning fluid towards a longitudinal axis of the chamber. In a third embodiment, a cleaning head (201) comprises an elongate, substantially rigid vacuum tube (240) for insertion longitudinally into the rectum of a carcass.

Description

CARCASS CLEANING DEVICES AND METHODS

The present invention relates to devices and methods for cleaning animal carcasses, particularly for the sterilisation and/or removal of visible contamination (e.g. dust, hair, faeces) and non-visible contamination (e.g. bacteria, especially E. coli) during the processing of animal carcasses in abattoirs.

EP 0 679 335 describes a device for this purpose, which consists of a hand-held wand, connected to a hot water supply and a vacuum pump. The principle behind the device is that hot water is sprayed from the wand on to an area of contamination of a carcass, thereby loosening the contamination, and the water and contamination are removed via the wand by the vacuum pump into a contamination collection system. The wand terminates in an open-mouthed vacuum cavity, which is connected to the vacuum pump by a vacuum line. The hot water is either sprayed from within the vacuum cavity and out of the open mouth (the "vacuum mouth") to make contact with the carcass, or from nozzles mounted outside the vacuum cavity. The hot water and loosened contamination are removed via the vacuum cavity and vacuum line into the contamination collection system.

It is not generally permissible to wash carcasses with water, since films or rivulets of water can allow bacterial contamination to spread across the surface of the carcass. Accordingly, EP 0 679 335 proposes that the bottom edge defining the vacuum mouth be brought into contact with the carcass, to prevent water running down the carcass, and for the wand to be moved upwards in use. To address the possibility of the edges defining the vacuum mouth carrying contamination along the surface of the carcass, EP 0 679 335 proposes that the outer surfaces of the vacuum mouth be bathed in steam from steam nozzles mounted on the external surfaces of the walls defining the vacuum cavity or from a steam shroud surrounding those external surfaces.

However, very significant problems remain with the device proposed in EP 0 679 335.

The device is poor ergonomically. It is awkward and inconvenient to move the wand in an upward direction; the handles of the device are mounted generally perpendicularly to the length of the wand and vacuum, hot water and (optional) steam lines, making control of the wand difficult; and the stiffness and inertia of the vacuum line in particular imposes drag- on the wand, making it difficult to manouevre.

Moreover, the device is still at risk of causing bacterial cross-contamination. The pressure of steam required to maintain the edges of the vacuum mouth at sterilisation temperatures (typically 81.5°C or above, according to government regulations) using jets as^' proposed in EP 0 679 335 is at least 70-80, and more plausibly about 100 psi, which would constitute an unacceptable hazard to operators of the device, and which could cause contamination to be driven into the carcass. A steam shroud has also been shown to be ineffective at maintaining the vacuum mouth edges at an adequate temperature . Accordingly, government approval has not been granted in various countries for devices such as those proposed in EP 0 679 335 to be used for carcass cleaning, and in particular, approval has not been granted for the device to be used by running the vacuum mouth along a carcass surface, rather than by placing the vacuum mouth over areas of contamination and then withdrawing the vacuum mouth from the carcass before positioning it over another area of contamination.

It would, however, be particularly advantageous to be able to run the vacuum mouth along the surface of a carcass, e.g. for large areas of contamination or for cleaning along cut lines of de-skinned carcasses (i.e. the lines along which the skin was cut for removal, and which commonly are contaminated with hair and dirt carried from the skin surface onto the underlying meat by the blade) .

The present invention is aimed at addressing these and other problems of the device of EP 0 679, 335.

Accordingly, in a first aspect, the present invention provides a carcass cleaning system comprising: a vacuum source; a cleaning head, having walls defining a vacuum chamber in communication via a vacuum line with the vacuum source, the vacuum chamber having an open vacuum mouth; and means for supplying a pressurised cleaning fluid via a fluid line to one or more cleaning fluid outlets within the vacuum chamber, the cleaning outlets being directed to spray cleaning fluid towards the vacuum mouth; whereby the vacuum mouth may in use be positioned adjacent or against a carcass to allow sprayed cleaning fluid to contact the carcass and be removed under vacuum via the vacuum line; characterised by any one, or any combination of more than one, of the features (a) , (b) , (c) , (d) and (e) :

(a) the cleaning head comprising a hollow handle of insulating material, the lumen of the handle being in communication with the vacuum mouth and vacuum line;

(b) the cleaning head being connected to the vacuum line via an articulated joint, thereby allowing relative movement between the cleaning head and the end of the vacuum line to which the cleaning head is connected; (c) means for supplying steam to a manifold on the cleaning head, the manifold having apertures through which steam may in use be directed towards vacuum mouth- defining portions of the walls of the cleaning head;

(d) the cleaning fluid outlet (s) being configured to spray cleaning fluid towards substantially the entire extent of the vacuum mouth; and

(e) the vacuum mouth being configured to allow the cleaning head to substantially vacuum lock on the surface of the carcass.

Features (a) and (b) have been found to improve greatly the ergonomics of the system, compared to systems such as those proposed in EP 0 679 335. Feature (c) has been found to allow the temperature of the walls defining the vacuum chamber to reach sterilisation temperature at lower steam pressures than steam jets from nozzles or steam shrouds. Feature (d) has been found to improve the sterilisation of the internal surfaces of the walls forming vacuum chamber at the vacuum mouth, compared with systems such as those proposed in EP 0 679 335, which indicates that it is desirable for the cleaning fluid not to contact the side walls of the vacuum chamber. This feature therefore reduces the chances of the side walls of the vacuum chamber spreading contamination when moved along the surface of a carcass. Feature (e) has been found to allow a better trade-off between removal of contaminants from carcasses and prevention of cleaning fluid from escaping removal under vacuum and may be provided by a vacuum mouth having smooth edges, rather than toothed or lobed edges, as disclosed in EP 0 679 335.

In particular, the system is preferably adjustable such that in use in a first state, with the cleaning head held clear of a carcass (or other surface) , the cleaning fluid is sprayed with sufficient velocity that a plume of cleaning fluid reaches the vacuum mouth before being drawn back into the vacuum chamber and thence into the vacuum line and in a second state, with the vacuum mouth near to or against the surface of a carcass, when airflow is reduced by obstruction of the vacuum mouth, the plume of cleaning fluid may protrude beyond the vacuum mouth before being drawn back into the vacuum chamber, thereby to impinge on the carcass surface for cleaning. It has been found that allowing the cleaning head to vacuum lock onto the surface of the carcass allows vigorous cleaning of the carcass, with efficient removal of cleaning fluid once airflow is restored by partially withdrawing the cleaning head from the carcass surface and that undesirable escape of cleaning fluid is also avoided when the cleaning head is clear of the carcass. When feature (a) is present, the cleaning head preferably comprises a guide for the cleaning fluid and/or steam lines, the guide providing a guard to shield an operator's hand from contacting the cleaning fluid and/or steam lines when holding the handle.

For this and the following aspects, the cleaning fluid preferably comprises hot water. Usually no other components of cleaning fluid are required.

In a second aspect the present invention provides the^' use of a carcass cleaning system according to the first aspect with the cleaning fluid pressure, vacuum pressure and airflow adjusted as described. Suitable values are about 10-30 (preferably about 20) psi for the cleaning fluid, 5-12 (preferably about 8) inches of mercury (inHg) for the vacuum and 100 cubic feet of air per minute airflow. Airflow values are for the unobstructed vacuum mouth .

Preferably the system comprises interchangeable cleaning heads, or a cleaning head with interchangeable parts. In particular, it may be desirable to change heads for cleaning or repair/replacement or to use heads with differently shaped vacuum mouths for different animal carcasses or for cleaning different parts of a carcass. The system may allow simultaneous operation of a plurality of cleaning heads, having respective cleaning fluid, vacuum and steam lines.

For example, for cleaning generally flat portions of a carcass, it is preferable to use a cleaning head having a generally oblong vacuum mouth, and one or more fishtail nozzles for the cleaning fluid outlet (s). Such cleaning heads are unsuitable for cleaning the ends of protruding portions of the carcass, e.g. knuckle ends of lamb and veal. A suitable cleaning head for such portions has a generally circular vacuum mouth and a nozzle which sprays cleaning fluid in a cone; the vacuum mouth can be fitted over the protruding end to clean it .

Accordingly, in a third aspect, the present invention provides a cleaning head as specified in the first aspect, for use in a cleaning system of the first aspect.

A further problem with the cleaning system described in EP 0 679 335 is that it is difficult to use it to clean limbs and other elongate portions of carcasses, particularly slender portions, having highly curved surfaces .

Accordingly, in a fourth aspect, the present invention provides a carcass cleaning system comprising: a vacuum source; a cleaning head comprising a vacuum chamber in communication via a vacuum line with the vacuum source, the vacuum chamber having an open mouth at a longitudinal end of the chamber; and means for supplying pressurised cleaning fluid via a fluid line to a plurality of cleaning fluid outlets within the vacuum chamber, which are directed to release cleaning fluid substantially towards a longitudinal axis of the chamber; whereby in use a limb, decapitated neck or other elongate portion of a carcass may be inserted longitudinally into the vacuum chamber via the mouth, to allow cleaning fluid to impinge on the carcass portion and be removed under vacuum via the vacuum line.

The size and shape of the mouth and vacuum chamber are preferably adapted for a particular animal part (e.g. leg of beef, neck of lamb) , though suitability for more than one animal part may be possible.

The fluid outlets are preferably nozzles, more preferably fishtail nozzles, which are capable of spraying water substantially in a sheet. In a particularly preferred embodiment, the cleaning fluid line terminates in a generally annular chamber bearing opposed fishtail nozzles, such that cleaning fluid may be sprayed in a substantially continuous sheet with the annulus . In an alternative embodiment, the cleaning fluid outlets may be provided by a mesh, though this is not preferred as the mesh may become blocked in use.

Preferably the cleaning fluid outlets are not directed perpendicular to the longitudinal axis of the vacuum chamber, but slightly (e.g. about 15°) away from the mouth of the vacuum chamber, to reduce the possibility of cleaning fluid escaping from the chamber.

During the processing of carcasses, it is necessary to remove the viscera, including the entire gut. Standard practice for the removal of the gut is to cut around the anus and to pull the entire gut out of the carcass through the (decapitated) neck. There is a risk when doing this that faeces in the rectum may escape through the anus and contaminate the abdominal cavity of the carcass. Much wastage and potential for contamination of the resultant meat products could be avoided if this problem were eliminated.

Attempts have been made to remove faeces from the rectum under vacuum, but these have proved unsuccessful as the rectum collapses under vacuum. Attempts have also been made to prevent rectal collapse by supplying air simultaneously with the vacuuming, but even then, it was found that faeces collected on the external surfaces of the vacuum wand, and was easily transferred on to the carcass when the wand was removed from the rectum.

Accordingly, the present invention provides in a fifth aspect, a system for removing the faeces from the rectum of a carcass, the system comprising: a vacuum source; a cleaning head comprising an elongate, substantially rigid vacuum tube for insertion longitudinally into the rectum of a carcass, the tube being in communication via a vacuum line with the vacuum source, and having an open vacuum mouth;, and means for supplying pressurised cleaning fluid via a fluid line to one or more cleaning fluid outlets disposed on the vacuum tube.

Preferably the cleaning fluid outlet (s) is/are disposed near the vacuum mouth. More preferably the cleaning fluid is supplied to a cleaning fluid jacket around the vacuum tube, in which case, the outlets are preferably apertures in the jacket; the outlets may suitably be arranged in a ring surrounding the vacuum mouth. As with previous aspects, the cleaning fluid preferably comprises hot water, in which case, the cleaning fluid jacket is preferably surrounded by an insulating jacket, to prevent faeces from adhering to the hot surface of the cleaning fluid jacket.

As with the first aspect, the cleaning heads of the fourth and fifth aspects may be interchangeable or have interchangeable parts. Accordingly, in further aspects, the present invention provides cleaning heads as specified in the fourth and fifth aspects, for respective use in the cleaning systems of those aspects.

As will be appreciated, a plurality of cleaning heads as defined in the first and/or fourth and/or fifth aspects may be used with a common vacuum source and cleaning fluid supply, but respective vacuum lines and cleaning fluid lines, e.g. at different cleaning stations in a meat processing plant.

Embodiments of the invention in its various aspects will now be described in detail, with reference to the accompanying drawings, in which:

Fig. 1 is a side view of a cleaning head of a carcass cleaning system according to the first aspect of the invention;

Fig. 2 is the opposite side view of the cleaning head of Fig. 1, with a handle of the cleaning head removed and part of a side wall cut away to show a nozzle inside the cleaning head;

Fig. 2A is a similar cut-away view of part of an alternative cleaning head in which the nozzle is in a different arrangement; Fig. 3 is a perspective view of a cleaning head of a cleaning system of the fourth aspect of the invention for cleaning elongate protruding portions of a carcass;

Fig. 4 is a perspective view of a cleaning head of a system of the fifth aspect of the invention for removing the faeces from the rectum of a carcass;

Fig. 5 is cross-sectional view along line 5 of Fig. 4;

Fig. 6 is a cross-sectional view of a further embodiment of a cleaning head of a cleaning system of the first aspect of the invention;

Fig. 7 is a side view of a further embodiment of a cleaning head of a cleaning system of the first aspect of the invention, with part of a side wall cut away to show a nozzle inside the cleaning head.

Shown in Fig. 1, a cleaning head 1 of a carcass cleaning system comprises upper 2, lower 4 and side 6 walls of stainless steel, which define a vacuum chamber 8, having a generally oblong open vacuum mouth 10 at one end of the chamber. At its other end, the vacuum chamber is in communication via a hollow insulating handle 12 of plastics material (e.g. "Delrin" (TM) ) with a vacuum line and vacuum source (not shown) .

The handle 12 and vacuum chamber 8 are configured such that when the handle is held in a pistol grip by an operator, the vacuum mouth 10 is inclined slightly to the vertical (line V) , with the upper wall 2 protruding slightly beyond the lower wall 4. The cleaning head can be drawn comfortably in a downwards direction with the upper wall in contact with a suspended carcass 13 and the lower wall spaced slightly from the carcass. The lower wall may also be brought into contact with the carcass (thereby allowing the cleaning head to vacuum lock onto the carcass) by a slight dipping of the wrist of the operator.

The handle 12 is connected to the vacuum line by a ball and socket joint 14 which provides articulation between the cleaning head and the 'vacuum line. The ball of the joint is borne on one end of a short length of tubing 16 which fits into the vacuum line for connection thereto.

A steam line (not shown) feeds steam via a steam- connector 18 mounted on the outside of the lower wall into a tube 20 which runs along the outside of the lower wall towards the vacuum mouth. The tube 20 feeds a steam manifold 22 which has the form of a looped tube encircling the vacuum chamber near the vacuum mouth. Apertures 24 in the steam manifold direct steam onto the external surfaces 2a, 4a, 6a of the vacuum chamber at the vacuum mouth, thereby to sterilise those surfaces.

Shown in Fig. 2, a fishtail nozzle 26 is_, disposed inside the vacuum chamber, directed towards the vacuum mouth. The nozzle is fed by a short length of tubing 28, which extends through the lower wall to a hot water connector 30 mounted on the outside of the lower wall adjacent to the steam connector 18, for connection to a hot water line (not shown) .

In an alternative embodiment, shown in Fig. 2A, the lower wall has a portion, the internal surface of which faces generally towards the vacuum mouth. The nozzle 26 is mounted directly in this portion, rather than (as in Fig. 2) at the end of the short length of tubing 28 which extends into and partially across the vacuum chamber. The arrangement^" of Fig. 2 can suffer from accumulation of debris around the tubing 28, particularly when cleaning wool or hair from carcasses. The arrangement of Fig 2A can avoid this problem by removing this tubing and mounting the nozzle directly on the lower wall of the vacuum chamber.

A metal guide 31 is connected at one end to the lower wall and extends parallel to the handle to a loop in which the steam and hot water lines are gathered. The guide also serves to protect the knuckles of an operator from contacting the lines, which have the potential to burn.

In use, with the vacuum mouth clear of any surface, the fishtail nozzle sprays hot water in use towards the vacuum mouth, where it washes the internal surfaces of the walls of the vacuum chamber, thereby to sterilise them. The sprayed water is drawn back under vacuum into the vacuum chamber (and via the vacuum line into a waste collector) , causing the water spray to form a plume which substantially fills, but substantially does not protrude beyond, the vacuum mouth. This is achieved by suitable shaping of the aperture in the fishtail nozzle, and suitable adjustment of water pressure, vacuum pressure and airflow.

As the vacuum mouth nears a surface, e.g. a carcass, airflow is reduced, allowing the plume of spray to protrude beyond the vacuum mouth before being drawn back into the vacuum chamber. The plume of spray impinges _ton the surface with a scrubbing action, which is highly effective at loosening and sterilising visible and non- visible contamination, which is carried into the vacuum chamber and into the waste collector along with the water. This effect is still more evident when the cleaning head vacuum locks onto the surface.

Controls (not shown) are provided in the system for adjusting pressure, temperature and airflow in the vacuum, steam and hot water lines. An air-triggered on/off hot water control (not shown) is provided for each cleaning head.

Shown in Fig. 3, a cleaning head 101 of a cleaning system for cleaning elongate protruding portions of a carcass has a generally cylindrical, hollow stainless steel vacuum chamber 108, which has at one end an open mouth 110 and which is in communication with a vacuum line (not shown) via a connector 129. An annular tube 131 is mounted on the internal surface of the vacuum chamber near the mouth and communicates via a hot water connector 130 on the outside of the cleaning head with a hot water line (not shown) . The annular tube feeds hot water to several fishtail nozzles 126, which are directed towards the longitudinal axis of the vacuum chamber and slightly away from the mouth.

Apertures 132 through the wall of the vacuum chamber prevent a vacuum lock forming, since stronger vacuums may be used with this system than that of Figs 1 and 2 (in which the vacuum lock may be easily broken by manual movement of the cleaning head) . In use, the cleaning head is manoeuvred by means of handles 133 over a protruding portion of a carcass, hot water is sprayed from the nozzles onto the carcass, sterilising it and removing contamination, which is drawn into the vacuum line along with the water. The cleaning head may be moved backwards and forwards along the protruding portion to ensure good cleaning.

A 45-60 lb balancer 134 is provided for easy manoeuvrability of the cleaning head. Controls are as described above, the air-triggered on/off hot water control 136 in this case being shown.

The vacuum chamber 108 is circumferentially surrounded, except near the mouth 110, by an insulating jacket 137 to reduce burn risk to operators.

Shown in Figs. 4 and 5, a cleaning head 201 of a cleaning system for removing the faeces from the rectum of a^" carcass comprises an elongate narrow vacuum tube 208 having an open vacuum mouth 210 at one end, the other end being in communication via connector 229 _to a vacuum line (not shown) .

A hot water jacket has a cylindrical outer wall 240 which surrounds the vacuum tube 208 and an end wall 242 hich meets the wall of the vacuum tube at the vacuum mouth. At its other end, the water jacket communicates with a hot water line (not shown) . The end wall has apertures 244 through which hot water is sprayed in use, the water then being drawn back along the vacuum tube.

Circumferentially surrounding the hot water jacket is <a sealed, hollow, air-filled insulating jacket 246.

An air-triggered on/off hot water control 236 is provided.

In use, the cleaning head is inserted (vacuum mouth first) via the anus into the rectum of a carcass, the water supply is turned on and water and faeces are drawn from the rectum into the vacuum tube . The supply of water prevents the rectum from collapsing under vacuum and assists in removing and sterilising faeces. The water supply is turned on as soon as the tip of the vacuum tube is located in the rectum, and the vacuum tube is then inserted slowly further into the rectum. This mode of operation minimises adhesion of faeces onto the outside of the vacuum tube, as does the use of an insulating jacket.

Shown in Fig. 6, a cleaning head has a generally frusto- conical wall 303 defining a vacuum chamber 308 having a vacuum mouth 310 at the wide end of the conical wall. At the other end, the vacuum chamber is in communication with a vacuum line (not shown) . A full nozzle 326, capable of generating a generally cone shaped water spray, is supported within the vacuum chamber by three equally spaced struts 348 which extend between the 'nozzle and the internal surface of the wall 303. The nozzle is directed towards the vacuum mouth. A tube 328, extends through the wall from a hot water connector 330 connected to a hot water line (not shown) to the nozzle to supply hot water to the nozzle. In use, the water and vacuum pressures are adjusted so that the water spray washes the internal surface of the conical wall at the vacuum mouth and is drawn back toward the longitudinal axis of the vacuum chamber and into the vacuum line, i.e. water does not escape the ^"cleaning head. The head provides an alternative means of cleaning protruding portions of a carcass, e.g. lamb neck, which are positioned in the vacuum chamber and sprayed.

Fig. 7 shows an embodiment similar to that of Fig. 6, for use particularly in cleaning narrower protruding portions, such as hocks and knuckle ends. Having a smaller cleaning head, however, it is intended to be interchangeable with the cleaning heads of Figs. 1 to 2A.

Like the embodiment of Fig. 6, it has a frusto-conical wall 403 defining defining a vacuum chamber 408 having a vacuum mouth 410 at the wide end of the conical wall. At the other end, the vacuum chamber is in communication via a curved tubular portion 413 which terminates with a screw thread for connection with a Delrin™ handle, as with the embodiments of Figs 1 to 2A. A full nozzle 426, capable of generating a generally cone shaped water spray, is disposed in the vacuum chamber and directed towards the vacuum mouth. A tube 428 bears the nozzle at one end, extends through the wall of the vacuum chamber and bears a hot water connector 430 at the other, for connection to a hot water line (not shown) to supply hot water to the nozzle. As with the embodiment of Fig. 6, the water and vacuum pressures and airflow are adjusted in use so that the water spray washes the internal surface of the conical wall at the vacuum mouth and is drawn back toward the longitudinal axis of the vacuum chamber and into the vacuum line, i.e. water does not escape the cleaning head. In all embodiments and aspects, the water temperature and flow rate will be set according to governmental regulations. However, it will normally be necessary to have a water temperature of at least 160°F (72°C) at the point of contact with the carcass. Higher temperatures, e.g. at least 80°C, 81.5°C or even 90°C are preferable. In the first embodiment, steam pressure and temperature will be set to ensure that the walls of the vacuum chamber are at sterilising temperatures at the vacuum mouth, where they come into contact with carcasses.

The embodiments of Figs. 3 to 7 will usually be sterilised by dipping in a sterilising solution between uses.

Claims

1. A carcass cleaning system comprising: a vacuum source; a cleaning head, having walls defining a vacuum chamber in communication via a vacuum line with the vacuum source, the vacuum chamber having an open vacuum mouth; and a pressurised cleaning fluid supply, which supplies said cleaning fluid via a fluid line to one or more cleaning fluid outlets within the vacuum chamber, the cleaning outlets being directed to spray cleaning fluid towards the vacuum mouth; whereby the vacuum mouth may in use be positioned adjacent or against a carcass to allow sprayed cleaning fluid to contact the carcass and be removed under vacuum via the vacuum line; characterised by any one, or any combination of more than one, of the features (a) , (b) , (c) , (d) and (e) : (a) the cleaning fluid outlet (s) being configured to spray cleaning fluid towards substantially the entire extent of the vacuum mouth;

(b) the cleaning head being connected to the vacuum line via an articulated joint, thereby allowing relative movement between the cleaning head and the end of the vacuum line to which the cleaning head is connected;

(c) means for supplying steam to a manifold on the cleaning head, the manifold having apertures through which steam may in use be directed towards vacuum mouth- defining portions of the walls of the cleaning head;

(d) the cleaning head comprising a hollow handle of insulating material, the lumen of the handle being in communication with the vacuum mouth and vacuum line; and (e) the vacuum mouth being configured to allow the cleaning head to substantially vacuum lock on the surface of the carcass.^"

2. A system according to claim 1 wherein the cleaning fluid pressure, vacuum pressure and/or airflow are adjustable such that the cleaning fluid is sprayed with sufficient velocity that: ^• in use in a first state, with the cleaning head held clear of a carcass or other surface, a plume of cleaning fluid is produced, the cleaning fluid travelling first towards the vacuum mouth and then substantially all the cleaning fluid being drawn back under the vacuum into the vacuum chamber and thence into the vacuum line; and in use in a second state, with the vacuum mouth near to or against the surface of a carcass, when airflow is reduced by obstruction of the vacuum mouth, the plume of cleaning fluid may protrude beyond the vacuum mouth before being drawn back into the vacuum chamber, thereby to impinge on the carcass surface for cleaning and then be drawn back into the vacuum chamber and thence into the vacuum line.

3. A system according to claim 1 or claim 2, wherein feature (d) is present and wherein the cleaning head comprises a guide for the cleaning fluid and/or steam lines, the guide providing a guard to shield a handle- holding hand of an operator from contacting the cleaning fluid and/or steam lines.

4. A carcass cleaning system comprising: a vacuum source; a cleaning head comprising a vacuum chamber in communication via a vacuum line with the vacuum source, the vacuum chamber having an open mouth at a longitudinal end of the chamber; and a pressurised cleaning fluid supply, which supplies pressurised cleaning fluid via a fluid line to a plurality of cleaning fluid outlets within the vacuum chamber, which fluid outlets are directed to release cleaning fluid towards a longitudinal axis of the chamber; whereby in use a limb, decapitated neck or other elongate portion of a carcass may be inserted longitudinally into the vacuum chamber via the mouth, to allow cleaning fluid to impinge on the carcass portion and be removed under vacuum via the vacuum line.

5. A system according to claim 4 wherein the fluid outlets are fishtail nozzles.

6. A system according to claim 4 or claim 5 wherein the cleaning fluid line terminates in a generally annular chamber bearing opposed fluid outlets.

7. A system according to any one of claims 4 to 6 wherein the fluid outlets are directed slightly away from the mouth of the vacuum chamber.

8. A system for removing the faeces from the rectum of a carcass, the system comprising: a vacuum source; a cleaning head comprising an elongate, substantially rigid vacuum tube for insertion longitudinally into the rectum of a carcass, the tube being in communication via a vacuum line with the vacuμm source, and having an open vacuum mouth; and a pressurised cleaning fluid supply, which supplies pressurised cleaning fluid via a fluid line to one or more cleaning fluid outlets disposed on the vacuum tube.

9. A system according to claim 8 wherein the cleaning fluid outlet (s) is/are disposed near the vacuum mouth.

10. A system according to claim 8 or claim 9 wherein the cleaning fluid is supplied to a cleaning fluid jacket around the vacuum tube.

11. A system according to claim 10 wherein the cleaning fluid outlets are apertures in the cleaning fluid jacket

12. A system according to claim 11 wherein the cleaning fluid outlets are arranged in a ring surrounding the vacuum mouth.

13. A system according to any preceding claim wherein the cleaning fluid comprises hot water.

14. A system according to claim 13 wherein the cleaning fluid comprises hot water in the substantial absence of other cleaning materials.

15. A system according to claim 13 or claim 14, as dependent from claim 8 wherein the cleaning fluid jacket is surrounded by an insulating jacket.

16. A system according to any one preceding claim having a plurality of cleaning fluid, vacuum and steam lines, thereby allowing simultaneous use of a plurality of cleaning heads.

17. A system according to any preceding claim, comprising interchangeable cleaning heads, or a cleaning head with interchangeable parts.

18. A system according to claim 17, as dependent from claim 1 or 4, wherein said different cleaning heads or parts thereof have differently shaped vacuum mouths or mouths for cleaning different animal carcasses or for cleaning different parts of a carcass.

19. A system according to any preceding claim, as dependent from claim 1, comprising a^' cleaning head having a generally oblong vacuum mouth, and one or more fishtail nozzles for the cleaning fluid outlet (s).

20. A system according to any one of claims 1 to 18, as dependent from claim 1, comprising a cleaning head having a generally circular vacuum mouth and a nozzle which sprays cleaning fluid in a cone.

21. A cleaning head as defined in any preceding claim.

22. The use of a cleaning head as defined in any one of claims 1 to 20 in a carcass cleaning system.

23. The use of a carcass cleaning system according to any one of claims 1 to 20, as dependent from claim 1, with the cleaning fluid pressure, vacuum pressure and/or airflow adjusted such that the cleaning fluid is sprayed with sufficient velocity that: in a first state, with the cleaning head held clear of a carcass or other surface, a plume of cleaning fluid is produced, the cleaning fluid travelling first towards the vacuum mouth and then substantially all the cleaning fluid being drawn back under the vacuum into the vacuum chamber and thence into the vacuum line; and in a second state, with the vacuum mouth near to or against the surface of a carcass, when airflow is reduced by obstruction of the vacuum mouth, the plume of cleaning fluid protrudes beyond the vacuum mouth before being drawn back into the vacuum chamber, thereby to impinge on the carcass surface for cleaning and then be drawn back into the vacuum chamber and thence into the vacuum line.

24. A method of cleaning a carcass, the method comprising: providing a carcass cleaning system according to any one of claims 1 to 20, as dependent from claim 1; applying vacuum to the vacuum chamber; supplying pressurised cleaning fluid to the cleaning fluid outlets; and positioning the vacuum mouth adjacent or against a carcass to allow sprayed cleaning fluid to contact the carcass and be removed under vacuum via the vacuum line, thereby to clean the carcass.

25. A method or use according to claim 23 or claim¹24 wherein the cleaning fluid pressure is 10-30 (preferably about 20) psi, and/or the vacuum pressure is about 5-12

(preferably about 8) inches of mercury (inHg) and/or the airflow is about 100 cubic feet of air per minute when the vacuum mouth is unobstructed.

26-. A method or use according to any one of claims 23_t to 25 wherein the cleaning head is allowed to vacuum lock onto the surface of the carcass.

27. A method or use according to any one of claims 23 to 26 wherein the cleaning head is moved in a downward direction across the surface of the carcass during cleaning, contact between the cleaning head and the carcass being maintained. •