GB2167284A - Carcass treatment - Google Patents

Abstract

A method and apparatus for use in dehairing a carcass wherein, in addition to any hot water and/or scraping treatment, the carcasses are subjected to flames at least during the scraping operation. The apparatus comprises a carcass support frame with open spaced supports 24 having a recess 28 defining a carcass cradle, and a retractable gate defined by spaced bars 30 which register with said spaced supports. Burners 72 are disposed above said cradle to play into said carcasses. A ribbon pilot or spark ignition is employed to ignite the burners. <IMAGE>

Description

SPECIFICATION Carcass treatment This invention relates to treating animal carcasses, specifically improvement of carcasses by at least partial depilation and lightly singeing in what is usually known as a pig-dehairing machine.

According to this invention, in addition to any hot water and/or scraping treatment for dehairing purposes, carcasses are subjected to flames, preferably as part of a scraping stage, then conveniently as a later if not final operation thereof.

In practice, flames can be directed downwardly onto the carcass concerned effectively to envelop same. Such carcass is conveniently then on an open work support towards which the flames are directed and can further be subjected to action by scrapers that turns the carcass before as well as during flaming.

Spaced support members allow scraper blades to act between those members.

A preferred carcass support presents a carcass-receiving recess or cradle and has a retractable gate to locate or assist locating the carcass in position for scraper action and flaming, preferably with an upwardly inclined carcass entry slope and a downwardly inclined carcass exit slope. Spaced gate elements may register with the above-mentioned spaced carcass support members.

A suitable burner system to provide the aforesaid flames comprises a plurality of spaced burner heads, say disposed in a line on branches from a main burner supply tube with the flow of fuel thereto, which could be a gas for example propane butane or natural gas, at some stage in or before the heads entraining combustion promoting gas, usually air, to achieve the desired combustion mixture at jets of the heads, and may be generally after the manner of the well-known Bunsen burners. Hygiene considerations make the use of stainless steel an advantage for such supply tube and branches.

Moreover, one embodiment described herein avoids the use of pilots for repeated light-up operations, which would be less economic and could otherwise be undesirable and disadvantageous in the context of the intended use where frequent cleaning of a de-hairing chamber is required, indeed it is.preferable to run water over the carcasses during de-hairing.

We prefer to use spark ignition operative throughout actual flaming periods. Using stainless steel gas supply tubing, an added or incorporated brass or bronze ring aids sparking relative to an electrode appropriately located and spaced therefrom within a downwardly open shroud of the head, which shroud can conveniently be of nickel-plated steel. Nevertheless, in another embodiment, a pilot is used to light up the mains burners. Preferably, the pilot is a ribbon burner.

It is envisaged that choice of regulated pressure and/or jet size should permit achievement of firm, generally conical, flames of lengths within the range of 250 mm to 1500 mm, and so permit a considerable flexibility of application to different types and makes of basic scraper type dehairing apparatus, particularly if the flaming provision is as a self-contained unit for ready installation.

Specific implementation of this invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a diagrammatic longitudinal side elevation of a typical dehairing station taken on line I-I of Figure 2; Figure 2 is a diagrammatic transverse sectional elevation of the typical dehairing station taken on line ll-ll of Figure 1; Figures 3, 4 and 5 are diagrammatic side, top and end views of a burner assembly; Figure 6 is a diagrammatic section of a burner; Figure 7 is a typical gas circuit diagram; Figure 8 is a typical electrical circuit diagram for manual operation; and Figure 9 is an end view of an alternative pilot burner.

Referring first to Figures 1 and 2, a dehairing station 10 in the forn of a side-entrant and-exit cabinet having end frames 12A, 12B, shown with legs to adjustable feet 16, and interconnected by upper beams 18A, 18B and lower beams 20A, 20B, and with a hood 22.

The lower beams 20A, 20B are at different heights and support vertical plates 24 at spaced intervals therealong, which plates have upper edges 26 that slope down from one side (entrant) to the other (exit) and are arcuately relieved medially at 28. The plates 24 constitute support members of an overall open-work carcass support, conveniently but not essentially for two carcasses simultaneously nose-to-tail along the length of the cradle-forming reliefs 28. Retention of carcasses in such cradle during dehairing is assured via a gate comprising spaced arcuate members 30 depending fron a rotary pivot shaft 33 and terminating in flat portions 34 registering with the plates 24.The rotary shaft 33 is suitable journaled (not shown) at least at its ends in the side frames 12 for rotation between the carcassretention position shown in solid lines in Figure 2 and a retracted carcass-release position shown dashed at 30' in Figure 2.

It will be evident that carcasses rolled onto the plates 24 from their upper ends will come to rest in the cradle-forming reliefs 28 and against the gate members 30.

The cradle-forming reliefs 28 are above and up-slope of the plates 24 from a scraper blade shaft 32 shown fitted to pass through slots 36 in the lower edges of the plates 24 and slots 38 in ends of the cabinet. The shaft 32 will be suitable journaled (not shown ) for rotation by a drive motor (not shown) and could be on a subframe system removable bodily from the cabinet. On the shaft 32 are sets of radial carriers 40 for flails 42 carrying scraper blades 44 with suitable respective securements indicated at 46 and 48, respectively. The flails 42 are resiliently flexible and the radial members 40 are of J-shape with their free ends 50 curved to support the flails 42 as they flex against a carcass in the cradleforming reliefs 28.As shown, those free ends 50 intrude into the cradle-forming reliefs 28 and, when the shaft is rotated clockwise in Figure 2, will each in turn assist in rotating a carcass in the cradle-forming reliefs 28 after the associated flail 42 and scraper blades 44 have engaged that carcass. The sets of radial members 38 and associated flails 42 are shown extending between successive ones of the plates 24, respectively, and each set is shown with six radial members 40/flails 42 at 60 intervals with successive sets 30 out of phase, see priming for reference 42 in Figure 2. Other spacings and relative phasing of the sets of radial members/flails could, of course, be adopted.

Moreover, intrusion of the radial members 40 and their associated flails 42 successively into the cradleforming reliefs 28 will when the gate members 30 are retracted, serve to lift carcasses and roll them out onto the downwardly sloping upper edges of the plates 24 so that the carcasses roll out of the exit side of the cabinet.

Water jets 54 are shown for spraying water, see dashed spray indication 56, onto carcasses in the cradle-forming reliefs 28 and/or as they leave same. The jets 54 are shown downwardly directed from branches 58 at intervals off a supply pipe 60. Further water jets are shown at 62 branched at 64 from a parallel supply pipe 66 and directed at the exit side of the cabinet. That will be where debris will tend to go if not to below the plates 24 in view of the relative locations of the cradle-forming reliefs 28 and the scraper shaft 32, and the direction of rotation of the latter, it being assumed that the cabinet has side closures while operating.

In addition for the purposes of implementing this invention, attention is drawn particularly to provision for applying flames, see 70, onto carcasses in the cradle forming reliefs 28. To that end, spaced burner heads 72 are shown on branches 74 depending from a main fuel supply tube 76. The burner heads 72 are shown below the level of the gate shaft 33 and directed at an angle towards the cradleforming reliefs 28.

A particular preferred flaming unit is shown in Figures 3 to 5, to which we now turn.

There, branches 74 to the burner heads 72 are shown secured see 78, 80 to a supporting beam 82, actually to the back of a Csection such beam itself secured back-to-back by welded fillets (see 84), at its ends to other short beams 86, 88. At inboard ends of the shortbeams 86, 88 they and the beam 82 have upstanding lugs 90, 92 for supporting the main fuel supply tube or mainfold 76. The whole forms a rigid unit readily secured in a cabinet such as that of Figures 1 and 2 via mounting holes at 94 to undersides of top beams of the end frames 12. A supply pipe is shown at 96 to an end of the main fuel pipe or mainfold 76, and electric wiring indicated at 98 for ignition purposes, and either or both cam preferably be at either end of the unit.

Fuel feeds of stainless steel and support work of corrosion protection constructional steel are suitable for the environmemt of use.

A particular preferred burner head as shown in section in Figure 6 as comprising a shroud or nozzle 100 about the end of a branch tube 72 and jet, for a gas fuel feed, the tube having orifices 104 for admixture of air to form a combustion mixture in the well-known Bunsen burner manner. The shroud 100 has an upper shoulder 106 that is pierced 104 for further air passage drawn by the flame when lit, see also holes 104 and serving to prevent flame damage to a spark electrode 108 operative to generate a spark onto a brass or bronze ring 110 and thereby assure ignition at the associated burner. It is intended that sparking occur for the whole time that the associated burner is intended to be producing a flame. Brass or bronze jets and heavily nickel-plated mild steel shrouds 100 are found to be satisfactory.The electrode 108 is shown in a holder 105 and wiring thereto is in a shielding tube 98'.

It is preferred to use a fixed orifice jet 102 and rely only on air-orifice (104) variation to adjust the flame length for any particular installation, say to produce up to 15% variation and by a collar not shown. However, further variation of flame length is available by using different size jets and/or air-orifices in order to produce the desired cone-like flame for different installations. Propane is found to be a suitable fuel gas.

In operation of apparatus hereof, carcasses will be loaded successively into the illustrated cabinet, say two at a time as previously mentioned, usually from a hot water treatment or scalding station, and held by the gate 30 while the scraper shaft 32 is rotated throughout presence of the carcass or carcasses. A typical dehairing cycle time is between 45 and 90 seconds with water applied via the jets 54 from the start of each cycle up to ignition of the flame producing heads 72 and then, if desired, after the flaming part of the cycle.

Basic gas flow control is shown in Figure 7 for a source 110 of propane gas through an accumulator type regulator 112, a manual shut off valve 114, a gas filter 116, automatic safety shut off provision shown as duplicate valves 1 18A and 118B, and a further manual shut off valve 52A to the manifold 76. Associated with the safety valving 118 is a gas pressure switch 122 branched from between the gas filter and the safety valving 118, such components being electrically supplied at 124 from a flamer control box 126 also serving to power the ignition electrodes 108 over lines 128, one per burner head 72, and control water supply valve 130 for the jets 54.

The flamer control box 124 houses circuitry shown in Fig re 8 as comprising ignition transformers 132, conveniently of twin outlet type, an overall cycle start relay 134, conveniently of press-button pneumatic delay type or fully automatically through the aforesaid control bar, and a time delay relay 136 presettable for desired flaming period (say 1 second to 20 seconds), plus a fuse 138 from the positive side of mains supply 140 conveniently taken from an emergency stop circuit for the dehairer station, and neon indicators 140 and 142 for "Cycle-ON" and "Cycle-Complete", respectively.

As will be clear from Figure 8, the ignition transformers 132 operate irrespective of gas supply, and cutting off water supply via valve 130 is also independent of whether gas is actually supplied, there being a short delay imposed by start relay 134 from operation to gas supply and ignition, say of 0.25 to 3 seconds. At the end of the period preset by relay 136, the gas supply valves 118 automatically cut off and the water supply valve 130 is restored to its on state. In the event of power failure, the gas valves 118 will close.

As just described, the flaming operation is initiated according to the machine-operator's judgement or fully automatically who may further change the presetting for its duration. It will, however, be evident that flaming may be interlocked automatically relative to a nominal dehairing cycle time, whether on a repetitive present basis, or on a basis that operation's judgement is constrained relative to indications of minimum and normal maximum scraper-only times prior to flaming.

In an alternative, preferred embodiment, a ribbon pilot burner manifold is employed in place of individual spark electrodes for each main burner. This comprises a pipe, indicated as 200 in Figure 3 having a plurality of pilot jets 213 disposed along the length thereof, and outwardly thereof spaced upper and lower flame retention strips 201, 203, between which and from which the ribbon pilot flame is developed. The construction is shown in further detail in Figure 9. The upper flame retention strip is welded to the pilot gas supply tube and the lower retention strip secured thereto, and spaced therefrom by bolts 205.

An air gap 207 is formed between the pilot supply tube and a turned out end 209 of the strip 203. A supporting framework 211 is provided for mounting the pilot in position.

The pilot is ignited once during each operating session of the machine, for example once a day.

The pilot burns with a ribbon flame, running the length of the pilot burner, and parts of the flame piay onto the main burner nozzles so that when the main burners are supplied with gas, the gas is ignited by the pilot flame.

Thus, the spark ignition components 98', 105 and 106 and 108 of Fig re 6 are omitted from the burners.

With such an embodinent, the flame control box 124 comprises timers, controllers, safety devices and an ignition transformer. The ignition transformer serving to light the pilot on start up of the machine. Relays are provided to control the supply of gas to the main burners by actuating the gas supply valves for the desired intervals.

Claims (16)

1. A method of treating animal carcasses which in addition to any hot water and/or scraping treatment of the carcass for dehairing purposes, the carcasses are subjected to flames.

2. A method as clained in claim 1 in which the carcasses are subjected to the flames as part of a scraping stage.

3. A method as claimed in claims 1 or 2 in which the carcasses are subjected to flames after the scraping stage.

4. A method as clained in any one of claims 1 to 3 in which the flames are directed downwardly onto the carcasses to effectively envelope same.

5. A method as claimed in claim 4 in which the flames emerge from a plurality of spaced burner heads, and the flame configuration is generally conical.

6. A method as claimed in any preceding claim in which the carcass is on an open work support towards which the flames are directed and is turned thereon by the action of the scrapers before as well as during flaming.

7. Apparatus for use in dehairing a carcass comprising a carcass support having a carcass-receiving recess or cradle and a retractable gate to locate or assist locating the carcass in position for scraper action and flaming.

8. Apparatus as claimed in claim 7 in which the carcass support members are spaced apart and the gate comprises a plurality of spaced gate elements which register with with spaced carcass support members.

9. Apparatus as claimed in claim 6 or 7 in which the carcass support has an upwardly inclined carcass entry slope and a downwardly inclined carcassed shape relative to said carcass receiving cradle.

10. Apparatus as claimed in claim 7, 8 or 9 in which a burner system provides the aforesaid flames and comprises a plurality of spaced burner heads.

11. Apparatus as claimed in claim 10 in which the spaced burner heads are disposed in a line on branches fron a main burner supply tube with the flow of fuel thereto.

12. Apparatus as claimed in claim 10 or 11 in which a pilot is used to ignite the main burners

13. Apparatus as claimed in claim 10 or 11 in which a spark ignition system is employed for each burner to ignite same.

14. Apparatus as claimed in claim 13 in which stainless steel is used for the gas supply tubing and an added or incorporated brass or bronze ring is employed to aid sparking relative to an electrode located and spaced therefrom.

15. A method of treating animal carcasses substantially as hereinbefore described with reference to the accompanying drawings.

16. Apparatus for use in dehairing a carcass constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.