MICROBIOLOGICAL SLAUGHTER BY HEAT TREATMENT OF LIVESTOCK CARCASSES

Abstract

The invention relates to a carcass buckling station (1) extending vertically along an axis XX' from a platform (2) positioned perpendicular to the axis XX' on which the buckling station is fixed; said buckling station comprising: a frame (3); a buckling chamber (4) located in the center of the frame and laterally closed by a first deflector (5) and a second deflector (6); a gas distribution device fixed to the frame (3) and comprising, on the one hand, a supply circuit comprising a combustible gas referred to as the intake circuit (7), and on the other hand, a combustion gas evacuation circuit referred to as the exhaust circuit; and a bridge (8) mounted on the frame; said bridge (8) mounted on the frame comprising: - a first pillar (9) comprising the first deflector; - a second pillar (10) arranged opposite the first pillar, comprising the second deflector;- a walkway (11) extending across the upper part of the flame-casting chamber, and connecting the first pillar to the second pillar; and at least one of the selected elements between the first and second pillars comprises a first combustion unit (12a) containing a combustible gas supply column (13) integrated into the gas distribution device and a set of five to twenty combustion nozzles (14) mounted on the supply column, the combustion nozzles opening transversely into the flame-casting chamber pointing towards the axis XX', in which the gas distribution device comprises a combustion gas recirculation system (15) connected to the exhaust circuit and opening into the flame-casting chamber. Figure for the abstract: 1;

Description

Title of the invention: MICROBIOLOGICAL REDUCTION BY HEAT TREATMENT OF LIVESTOCK CARCASSES Technical field of the invention

[0001] The present invention relates to a singeing station intended for the surface heat treatment of carcasses of farm animals after their slaughter, and relates more particularly, but not exclusively, to the treatment of pig carcasses.

[0002] The invention also relates to a method for monitoring and homogenizing the singeing temperature of pig carcasses using such a singeing station, a use of such a singeing station for carrying out disinfection of the carcasses and a method for using such a singeing station. Technical background

[0003] Conventionally, an oven is used for burning the carcasses of livestock in order to ensure cleaning, or even elimination of almost all of the residual materials present on the surface of the carcasses. For the purposes of the present invention, the term "carcass" refers to what remains of an animal's body after slaughter and removal of hair (or feathers), which are referred to as bristles in the case of pig carcasses. A carcass that has undergone an additional evisceration step, that is, after the viscera have been removed, is called an "eviscerated carcass." A carcass said to be ready for butchery operations must have been dressed, that is to say that the viscera, the skin, the fat and possibly the nerves present between the skin and the muscles must be removed, and is referred to as a "dressed carcass". More generally, in the context of the invention, the term "carcass" can also designate only a part of the animal's body, for example without the feet (pig), without the beak (poultry), or even designate only all or part of a limb, the trunk, or simply the head of the animal.

[0004] The carcass surface treatment oven is usually placed on a slaughter line, and as far as the slaughter of pigs is concerned, said oven is located downstream of the dehairing machines whose function is to rid the skin of the majority of the animal's bristles, and possibly the brushing machines whose role is to eliminate as much as possible the residual bristles on the pig carcasses. The surface treatment oven is generally located on the slaughter line upstream of the stations dedicated to the internal treatment of pigs by evisceration, before the cutting steps which concern the butcher shop strictly speaking. Such a carcass surface treatment furnace is described in application FR2350788, and can be used in slaughterhouses suitable for the slaughter and packaging of meat from farmed pigs. The burning or roasting furnaces described in the preamble to this application FR2350788 comprise a passageway provided with an inlet and an outlet, a refractory lining placed laterally on the passageway, as well as burners which act directly on the slaughtered animals passing through the furnace using free flames. Said refractory lining is described as acting by heat radiation by being heated using burners fueled by gas or petroleum-derived products. Such state-of-the-art furnaces have the function of burning the hair and heating the skin so that its upper layer can be removed.The furnace described in particular in application FR2350788 is an electric furnace requiring the presence of elements for rotating the carcass to obtain optimum efficiency. These additional elements complicate and slow down implementation, given that this requires at least one additional rotation step to allow more uniform heating of a carcass.

[0005] All the ovens of the prior art have the disadvantage of not being able to ensure a real microbiological reduction, that is to say to sufficiently eliminate microbial germs naturally present on the surface of the carcasses while controlling the energy costs linked to the operation of the oven. Summary of the invention

[0006] The invention proposes, with a view to remedying the drawbacks of the state of the art, a carcass singeing station extending vertically along an axis XX' from a platform positioned perpendicular to the axis XX' on which the singeing station is fixed; said singeing station comprising: a chassis; a singeing enclosure located in the center of the chassis and being closed laterally by a first deflector and a second deflector; a gas distribution device fixed to the chassis and comprising, on the one hand, a supply circuit comprising a combustible gas referred to as an intake circuit, and on the other hand, a combustion gas evacuation circuit referred to as an exhaust circuit; and a bridge mounted on the chassis; said bridge mounted on the chassis comprising: - a first pillar comprising the first deflector; - a second pillar arranged opposite the first pillar, comprising the second deflector; - a footbridge extending across the upper part of the buckling enclosure, and connecting the first pillar to second pillar; and at least one of the elements selected between the first and the second pillar comprises a first burning unit containing a fuel gas supply column integrated into the gas distribution device and a set of five to twenty burning nozzles mounted on the supply column, the burning nozzles opening transversely into the flaming enclosure pointing towards the axis XX', the gas distribution device comprising a burnt gas recirculation system connected to the exhaust circuit and opening into the flaming enclosure.

[0007] Thanks to such a configuration of the singeing station according to the invention, it is possible to achieve sufficient microbiological reduction on the carcasses, to meet the hygiene and safety standards which govern the consumption of meat from farm animals. Such microbiological reduction is decisive for the hygienic quality of meat sold by the slaughterhouse: - a division of at least by 1000 of the total microbial flora can be achieved by implementing the flambéing station according to the invention, which makes it possible to ensure a sufficient lifespan for the meats and products made from this meat; - in addition, the prevalence of pathogenic flora (listeria and salmonella) is considerably reduced on pieces sold for processing; - in addition, the application of the exemption to the transport temperature is made possible since a value of less than 10,000 CFU / cm2 of total microbial flora on the transported carcasses is reached, and meets the requirements of Regulation (EU) 2017 / 1981. Along with refrigeration, singeing is one of the areas that consumes the most energy in a pig slaughterhouse. The singeing station according to the invention thus enables considerable energy savings to be made.

[0008] Preferably, the exhaust circuit comprises an exhaust chimney and a dome which flares from one end of the chimney and opens in the upper part of the enclosure.

[0009] The system for recirculating the burnt gases of the singeing station according to the invention as described previously in the context of the invention advantageously comprises recirculation pipes mounted on the exhaust circuit and which open into the singeing enclosure in the lower part, that is to say below the part of the enclosure into which the burning nozzles open. Preferably, the recirculation pipes are mounted on the exhaust chimney. Such a design makes it possible to reduce gas consumption significantly in re injecting hot air into the singeing area, ideally under the carcasses undergoing singeing.

[0010] The system for recirculating the burnt gases of the carcass singeing station according to the invention advantageously comprises an injection means capable of propelling the gases from the exhaust circuit into said recirculation pipe. Preferably, the injection means is a fan, designated an injection fan. The injection fan is chosen so that it allows at least one third of the burnt gases to be reinjected into the singeing enclosure, and is capable of operating at flue gas temperatures of 250 to 350°C. Preferably, the supply circuit comprising a combustible gas referred to as an intake circuit comprises an air-gas mixture.

[0011] Advantageously, in the carcass singeing station according to the invention, the first pillar comprises the first burning unit and a second burning unit positioned laterally around the first deflector, the second burning unit being configured in accordance with the first burning unit; and the second pillar comprises a third and a fourth burning unit positioned laterally around the second deflector while being configured in accordance with the first burning unit. Such a configuration makes it possible to have four series of flames directed towards the carcass for better singeing efficiency.

[0012] Advantageously, in the carcass singeing station according to the invention, the chassis comprises at least four feet intended to be fixed on said platform and an apron at least partially masking the openings between the feet. Such an apron allows partial masking in the lower part to improve the reinjection of gases in the lower part, while avoiding too much heat loss and allowing sufficient fresh air to pass through to oxygenate the enclosure. Preferably, the apron is a metal skirt fixed to the frame in the lower part of the buckling enclosure on the first and second pillars.

[0013] Advantageously, the first and second deflectors of the singeing station according to the invention are concave in shape and positioned relative to each other in a diametrically opposite manner relative to the axis XX'.

[0014] Advantageously, the walkway of the bridge of the carcass singeing station according to the invention comprises a passage incorporating fixing means provided for the mounting of an overhead conveyor line capable of conveying the carcasses into the enclosure of the singeing station.

[0015] The present invention also relates to a method for monitoring and homogenizing the singeing temperature of pig carcasses using a singeing station as presented previously in the context of the present invention, a thermal camera and a thermal analysis unit connected to the camera, comprising the following steps: - bring at least one carcass into the singeing chamber and start the singeing; - film the buckling of the carcass and transmit the data to the thermal analysis unit; - process the data within the thermal analysis unit to obtain temperature curves as a function of the position on the spine. Such temperature curves make it possible to check that the heat is well distributed uniformly on the surface of the carcass, with an ideal desired value of 47°C, so as to eliminate up to 99.9% of the microbial agents present on the surface of the carcasses. The method for measuring such microbiological reduction is described in the reference: Le Roux, A. et al, Meat inspection, quality, hygiene, safety and preservation, Decontamination on pork carcasses: Qualification of thermie treatment by thermal imaging, Safepork 2015 Conference, 2015, 75-79. Such a process according to the invention allows the monitoring and validation of the installation to allow for derogation from the obligations concerning the maintenance of a temperature of 7°C of the carcasses treated according to this process, and to verify that the installation is not energy-intensive.

[0016] The present invention also relates to a use of a flaming station as presented previously within the framework of the present invention, for flaming pig carcasses with a view to carrying out disinfection of the carcasses, the disinfection consisting of a reduction in the microbe content, preferably a reduction in the bacterial flora.

[0017] The present invention also relates to a method of using a singeing station according to the invention, comprising the following steps: - pass at least one carcass through the singeing chamber; - possibly operate doors to close access to the flaming enclosure; - start up the burning units and the gas recirculation system; - allow the singeing to reach a temperature of at least 47°C on the surface of the carcass for a period allowing 99.9% decontamination; and - scroll the said carcass to remove it from the enclosure.

[0018] The temperature on the surface of the carcasses is measured with an infrared thermal camera. Brief description of the figures

[0019] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows, given solely for illustrative purposes and in a non-limiting manner, and for the understanding of which reference will be made to the attached drawings, in which:

[0020] [Fig.l] - [Fig.l] is a side view in the direction of the axis YY', that is to say in the direction of movement of the carcasses, of an embodiment of a singeing station according to the invention shown without the burnt gas recirculation system;

[0021] [Fig.2] - [Fig.2] is a top view of the embodiment shown in [Fig.l], the axes YY' and ZZ' materialized on the ground, that is to say at the level of the platform on which the buckling station is fixed, are intersected by the axis XX' at their point of intersection;

[0022] [Fig.3] - [Fig.3] is a side view in the direction of the ZZ' axis, i.e. from the rear of one of the pillars, of the embodiment of the flambéing station according to the invention shown in [Fig.l], shown with the burnt gas recirculation system and the extractor hood;

[0023] [Fig.4] - [Fig.4] is a side view in the direction of the YY' axis of the mode of realization presented in [Fig.3];

[0024] [Fig.5] - [Fig.5] shows on the left an image taken directly with a infrared camera and the analyzed area (white line) after image processing on the spine of a pig during flambéing, right;

[0025] [Fig.6] - [Fig.6] shows a temperature curve obtained from a station of buckling of the prior art;

[0026] [Fig.7] - [Fig.7] shows temperature curves obtained from a station of flambéing according to the invention, with and without starting the burnt gas recirculation system; and

[0027] [Fig.8] - [Fig.8] shows non-ideal temperature profiles obtained on four carcasses in a prior art singeing station. Detailed description of the invention

[0028] For the description of the invention and the understanding of the claims, the axes XX', YY' and ZZ' illustrated in Figures 1 and 2, in relation to all or part of an embodiment according to the invention, are used as a spatial reference. The axis XX' is substantially vertical relative to the terrestrial reference frame, and the terms "top", "bottom", "top part" and "bottom part" qualify a relative height on this axis XX' of an element of a buckling station 1 relatively to a platform 2 on which the station is to be mounted.

[0029] In the following description, identical, similar or analogous elements will be designated by the same alphanumeric references.

[0030] Figures 1 to 4 show a carcass singeing station 1 crossed in its center by the axis XX'. The singeing station 1 is fixed by bolting on a platform 2 which is crossed by two perpendicular axes YY' and ZZ', and cut both perpendicularly by the axis XX'. The singeing station 1 comprises: a frame 3; a singeing enclosure 4 located in the center of the frame and being closed on either side of the axis YY' by a first deflector 5 and a second deflector 6, both of concave shape and placed diametrically opposite each other relative to XX'. The station according to the invention also comprises a gas distribution device fixed to the frame 3 and which integrates, on the one hand, a supply circuit comprising a combustible gas referred to as the intake circuit 7, and on the other hand, a combustion gas evacuation circuit referred to as the exhaust circuit.The station according to the invention also integrates a bridge 8 mounted on the chassis 3, which bridge comprises a first pillar 9 comprising the first deflector; a second pillar 10 arranged opposite the first pillar, comprising the second deflector; and a footbridge 11 providing the connection between the first and second pillars, for example using metal sleepers. According to an advantageous embodiment, the first and second pillars each comprise two burning units, constituting in total four burning units 12a-12d each containing a fuel gas supply column 13 integrated into the intake circuit 7 of the gas distribution device. According to a preferred embodiment, the supply column is supplied with an air / gas mixture so that the gas mixture which comprises the fuel gas is enriched with oxygen. The admission

[0031] of gas into the burning units 12a-12d is controlled by a solenoid valve. The fuel gas arrives at the head of the fuel gas supply columns via an injector whose diameter is adapted to the calorific value of the gas and its pressure. A fan, designated a supply fan, at the head of the column sends air and propels the air-gas mixture into the column. The air intake is adjustable by means of a flap at the inlet of the supply fan.A pilot light located at the bottom of the column is regulated by a flame controller, capable of cutting off the gas supply if the pilot light goes out. The air-gas mixture exits through the burner nozzles and is ignited by the pilot light starting at the bottom of the column. Each burning unit 12a to 12d comprises a set of five to twenty burning nozzles 14 mounted on the feed column, the burning nozzles opening transversely into the flaming enclosure pointing towards the axis XX'. According to a particularly advantageous embodiment, the five to eight burning nozzles 14 placed on a section occupying the first third in the lower part of the combustible gas supply column 13, that is to say those closest to the platform 2, have a heating power two to three times greater than the other nozzles. In a complementary or alternative manner, it can be provided that the number of burning nozzles 14 is greater on the above-mentioned section of the column in the lower part than towards the top of the flaming station.

[0032] Remarkably, the gas distribution device of the singeing station 1 according to the invention comprises a burnt gas recirculation system 15 connected to the exhaust circuit and opening into the singeing enclosure.

[0033] According to one embodiment, the exhaust circuit positioned in the upper part of the singeing station 1 comprises an extractor hood comprising a dome 16 and an exhaust chimney 17, the dome widening from one end of the chimney 17 and opening into the upper part of the singeing enclosure 4 of the singeing station.

[0034] According to an advantageous embodiment, the burnt gas recirculation system 15 comprises recirculation pipes 18 mounted on the one hand on the exhaust chimney 17, and which open on the other hand into the enclosure below the fuel gas supply columns. Such a configuration makes it possible to propel already heated air from below and guarantees a uniform distribution of the temperature on the surface of the carcasses, while reducing heat losses by improving the singeing efficiency.

[0035] The flue gas recirculation system 15 comprises an injection fan 19 capable of propelling the gases from the exhaust circuit into the recirculation pipes 18. The injection fan must reinject at least one third of the flue gases into the flaming enclosure, and operates at flue gas temperatures of 250 to 350°C. The injection fan 19 is a centrifugal fan comprising a frequency converter for adjusting the flow rate, from the OMEGA TI 175-2™ series and marketed by the company France Air®. A measurement made it possible to find a flow rate of 4230 m3 / h at 277°C. The desired flow rate of 1400 m3 / h falls within the fan curve and the accepted temperature is 450°C.

[0036] The frame 3 of the singeing station 1 comprises eight feet 20 screwed, or bolted, onto the platform 2; and an apron 21, in the form of a metal skirt, covering a large part of the openings between the feet 20. Such a skirt makes it possible to avoid too much heat loss during the propulsion of the gases reinjected from below, while allowing sufficient fresh air rich in oxygen to pass through to activate the flames of the singeing nozzles 14. The walkway 11 of the deck 8 comprises a passage 22 incorporating fixing means provided for the mounting of an overhead conveyor line capable of conveying the carcasses into the enclosure of the singeing station; the pig carcasses can thus be brought directly into the enclosure of the station to undergo singeing. Fire doors can also be installed, which open to allow the carcasses to enter or exit, and must be closed during singeing.

[0037] A method for monitoring and homogenizing the temperature of singeing of pig carcasses is implemented by monitoring the singeing in the singeing station. 1 using an infrared (IR) camera and a dedicated thermal analysis unit; [Fig.5] shows on the left an image taken directly with the camera and the analyzed area (white line) after image processing on the animal's spine, on the right. The IR camera is of the FLIR E60™ type marketed by FLIR Systems Advances Thermal solutions SAS®; the software used for thermal data analysis is ImageJ™ software.

[0038] The processed images make it possible to obtain temperature curves which are shown in Figures 6 and 7. [Fig.6] shows a temperature curve obtained from a prior art singeing station with no modifications to the burners, and also without a burnt gas recirculation system or an apron in the lower part. Other conventional temperature profiles are also shown in [Fig.8] for four carcasses successively treated and analyzed in the prior art singeing station: it is clearly visible that certain parts of the pigs are overheated compared to the objective of 47°C, the limit of microbiological effectiveness, and others are not heated enough.

[0039] [Fig.7] shows temperature curves obtained from a singeing station according to the invention with an apron in the lower part, without operating the burnt gas recirculation system for the so-called "control" curve, and after starting the gas recirculation for the curve referred to as "recirculation". The technical improvements of the station according to the invention make it possible to obtain a flatter temperature curve, and therefore a more homogeneous singeing temperature on the surface of the carcass.

[0040] Characterization of the furnace and traceability of the temperature at the furnace outlet: Temperature measurements taken on a sample of pigs with the IR camera make it possible to verify the effectiveness of the singeing station and to guarantee that with the settings (flow rate, time) recorded during the tests, the singeing pigs have reached at least 47°C on the surface and are therefore decontaminated to a level of 99.9% (suitability for application of the exemption from transport temperature, compliance with specific specifications: regulation (EU) 2017 / 1981).

[0041] The present invention makes it possible in particular to achieve, or improve: Energy saving: taking into account that the target temperature is 47°C on the surface, having verified the efficiency of the flaming station and refining the gas flow settings makes it possible to flatten the curve of the pork temperatures measured in the longitudinal direction, and to be able to reduce the flaming time and / or gas flow rate. Microbiological quality: after passing through the oven, the pork is 99.9% decontaminated if it has reached 47°C on the surface. It is then sufficient to trace the pork to the cutting, or to the shipping dock, to predict its ability to meet a particular specification or its ability to deviate from the temperature constraint for the transportation.

[0042] Traceability can be achieved using chip trolleys, into which the temperature at the oven outlet will be entered.

[0043] Once the oven has been characterized by a typical temperature curve along the vertebral axis of the pig, obtained using a thermal camera (IR), it will be sufficient to take the surface temperature at a representative point to deduce the temperature obtained on the rest of the carcass. A single measurement will make it possible to know whether the pig complies with the targeted microbiological objective.

[0044] LEGEND 1: flambéing station 2: platform 3: chassis 4: buckling enclosure 5: first deflector 6: second deflector 7: intake circuit 8: bridge 9: first pillar 10: second pillar 11: footbridge 12a-12d: Burning unit 13: fuel gas supply column 14: Burning nozzles 15: flue gas recirculation system 16: dome of the extractor hood 17: extractor hood exhaust chimney 18: recirculation pipes 19: injection fan 20: feet of the flambéing station

Claims

Claims

1. Singeing station (1) for carcasses extending vertically along an axis XX' from a platform (2) positioned perpendicular to the axis XX' on which the singeing station is fixed; said singeing station comprising: a chassis (3); a single chamber (4) located in the center of the chassis while being closed laterally by a first deflector (5) and a second deflector (6); a gas distribution device fixed to the chassis (3) and comprising, on the one hand, a supply circuit comprising a combustible gas referred to as an intake circuit (7), and on the other hand, a combustion gas evacuation circuit referred to as an exhaust circuit; and a bridge (8) mounted on the chassis; said bridge (8) mounted on the chassis comprising: - a first pillar (9) comprising the first deflector; - a second pillar (10) arranged opposite the first pillar, comprising the second deflector;- a walkway (11) extending in the upper part of the singeing enclosure, and connecting the first pillar to the second pillar; and at least one of the elements selected between the first and the second pillar comprises a first burning unit (12a) containing a combustible gas supply column (13) integrated into the gas distribution device and a set of five to twenty burning nozzles (14) mounted on the supply column, the burning nozzles opening transversely into the singeing enclosure pointing towards the axis XX', characterized in that the gas distribution device comprises a burnt gas recirculation system (15) connected to the exhaust circuit and opening into the singeing enclosure.;

2. A carcass singeing station (1) according to claim 1, in which the burnt gas recirculation system (15) comprises recirculation pipes (18) mounted on the exhaust circuit and which open into the singeing enclosure (4) in the lower part, that is to say below the part of the enclosure into which the burning nozzles (14) open.

3. A carcass singeing station (1) according to claim 2, wherein the burnt gas recirculation system (15) comprises an injection means, preferably an injection fan (19), capable of propelling the gases from the exhaust circuit into the exhaust pipes. recirculation (18).

4. A carcass singeing station (1) according to one of claims 1 to 3, wherein the first pillar (9) comprises the first burning unit (12a) and a second burning unit (12b) positioned laterally around the first deflector (5), the second burning unit (12b) being configured in accordance with the first burning unit (12a); and the second pillar comprises a third and a fourth burning unit (12c, 12d) positioned laterally around the second deflector (6) being configured in accordance with the first burning unit (12a).

5. Singeing station (1) for carcasses according to one of claims 1 to 4, in which the chassis comprises at least four feet (20) intended to be fixed on said platform (2) and an apron (21) at least partially masking the openings between the feet (20).

6. Singeing station (1) according to one of claims 1 to 5, wherein the first and second deflectors (5, 6) are concave in shape and positioned relative to each other diametrically opposite to the axis XX'.

7. A carcass singeing station (1) according to one of claims 1 to 6, wherein the walkway (11) of the bridge (8) comprises a passage (22) incorporating fixing means provided for mounting an overhead conveyor line capable of conveying the carcasses within the enclosure of the singeing station.

8. Method for monitoring and homogenizing the singeing temperature of pig carcasses using a singeing station (1) according to one of claims 1 to 7, a thermal camera and a thermal analysis unit connected to the camera, comprising the following steps: - causing at least one carcass to enter the singeing chamber and triggering the start of the singeing; - filming the singeing of the carcass and transmitting the data to the thermal analysis unit; - processing the data within the thermal analysis unit to obtain temperature curves as a function of the position on the spine.

9. Use of a flaming station according to one of claims 1 to 7, for flaming pig carcasses in order to carry out disinfection of the carcasses, the disinfection consisting of a reduction in the microbe content.

10. Method of using a singeing station according to one of claims 1 to 7, comprising the following steps: - pass at least one carcass through the singeing chamber; - possibly operate doors to close access to the flaming enclosure; - start up the burning units and the gas recirculation system; - allow the singeing to reach a temperature of at least 47°C on the surface of the carcass for a period allowing 99.9% decontamination; and - scroll the said carcass to remove it from the enclosure.

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