GB2263389A

GB2263389A - Rack and oven for cooking foodstuff

Info

Publication number: GB2263389A
Application number: GB9305519A
Authority: GB
Inventors: Edward Thomas Clarke; Harvey William Jull
Original assignee: Sun Valley Poultry Ltd
Current assignee: Sun Valley Foods Ltd
Priority date: 1989-06-03
Filing date: 1993-03-17
Publication date: 1993-07-28
Anticipated expiration: 2013-03-17
Also published as: GB9305519D0; GB2263389B

Abstract

A rack for cooking foodstuff comprises a frame (6), preferably comprising a pair of spaced longitudinal frame elements (8), between which extend a plurality of transverse elements. Each support element (12) preferably is of inverted U-shape, and is inclined to the general plane of the frame, at an angle conveniently of between 30 DEG and 60 DEG , allowing the support element to be inserted into an interior body cavity of poultry. The oven comprises an inlet opening preferably adjacent to a loading station (32) and an outlet opening which preferably extends directly into a cooling device (33), an unloading station, adjacent to the outlet, and a washing station at which the racks and conveyor are cleansed, prior to returning to the loading station. Each rack comprises a temperature sensing device (14) comprising a probe (16) which may be inserted into the meat on the rack, the probe being connected to a housing of the device by a flexible connector (18). specifically to two outlet terminals (20), the voltage across which being proportional to the temperature sensed by the probe (16). Preferably, provided at spaced intervals beneath the conveyor (36) are sensing elements in the form of flags (50), extending into the path of travel of the racks on the conveyor so as to engage the outlet terminals (20) of the sensing device (14). In this manner, as a rack passes each sensing element (50) the temperature sensed by the probe (16) thereof will be picked up by the element (50), conveniently for transmission to and displayed at a VDU located at a remote position. The temperature may also be relayed by radio. <IMAGE>

Description

Title: Improvements relating to cooking foodstuff Description of Invention This invention is concerned with improvements relating to cooking foodstuff. The invention has been devised particularly for the cooking of poultry: it is however to be appreciated that the invention may be utilised to advantage, in other cooking processes where similar or analogous problems arise, in relation to which the present invention has been devised.

According to this invention there is provided an oven for the cooking of foodstuff, said oven having an inlet and an outlet, conveyor means extending between the inlet and outlet, by which rack or trays containing the foodstuff may be conveyed through the oven, means to provide a controlled atmosphere in the oven, and means to sense the temperature of the foodstuff as it is conveved through the oven.

Preferably the oven comprises meons to circulate heated aiid preferably moistened air through the oven, to cook the foodstuff as it is conveved through the oven, and preferably said circulation means is operative to deliver air into the oven so that the air flows rear'vatdlv in the direction of passage of foodstuff through the oven.

Advantageously the oven forms part of a closed circuit, comprising cooling means, and conveyor means extending trotll the cooler outlet to an unloading station, and thence to a washing statioll at which the trays or racks are washed, prior to return to the loading station adjacent to the oven door.

Advantageously the cooler outlet is in a sterile area, to avoid contamination of the cooked meat with uncooked meat.

According to this invention there is also provided, in combination, an oven for cooking foodstuff and a rack upon which the foodstuff may be mounted, the oven comprising conveyor means to convey successive racks through the oven from an inlet to the outlet, each rack comprising temperature sensing means comprising a sensor probe, which may be inserted in articles of foodstuff on the rack, and means by which the temperature sensed by each sensor probe may be determined as the rack travels through the oven.

If desired the temperature sensed by each probe may be determined continuously, such as by a radio transmission system, and received by a remote receiver and displayed on such as a PC terminal.

Alternatively however means may be provided which is co-operable with the probe from time to time as it passes through the oven, by which the temperature sensed by the probe may be determined. Thus the temperature sensing device may comprise a control box, from which the probe extends, the control box comprising contact elements which may be engaged by sensing devices, as the rack travels through the oven, an output from the sensing device relating to the output from the control box, and hence the temperature sensed by the probe.

The output from the sensing device may be fed to a radio transmitter, to be picked up by a receiver and applied to a video display unit as aforesaid, or may be fed to a video display unit by fixed wiring extending through the oven wall.

Preferably a plurality of such sensing units are provided between the oven inlet and outlet, so that the temperature of the article to which the probe is connected may be monitored as the article travels through the oven.

Particularly in relation to the cooking of poultry, this enables the temperature of the bird to be monitored, to ensure that it reaches a cooked condition before it leaves the oven through the outlet.

Thus desirably the oven comprises means operative in the event that the temperature sensed by the sensing devices falls below a predetermined level, to take some remedial action.

The remedial action may be to cause a warning signal to be activated, to alert an operative to the situation, so that if necessary he may (for example) slow down the rate of feed of the conveyor through the oven, or to manually adjust temperature controls to the oven.

In addition, by the use of the invention above described, the temperature profile through the oven at different positions thereof, under varying conditions, may be measured, so that optimum cooking of the poultry as it passes through the oven may be ensured.

Preferably the cooked meat passes from the oven into a cooling device, within which the meat is rapidly chilled, prior to passing to an unloading station.

Advantageously the cooling device comprises means by which the temperature sensed by each sensor probe may be determined as the rack travels through the cooling device, and preferably said means is similar to the means by which the temperature of the foodstuff is determined as it passes through the oven.

Preferably each rack comprises a frame of open-work construction, frame elements thereof supporting a plurality of upwardly-extending support elements.

The frame preferably comprises two longitudinal frame elements and a plurality of transverse frame elements extending between the longitudinal elements. Conveniently the support elements extend upwardly from the transverse frame elements. Preferably the elements are generally of inverted U sh'tpe, and advantageously are inclined to the frame at an acute angle, convelliclltly of between (e.g.) 30 and 60".

Advantageously a first plurality of support elements extend upwardly from alternate transverse elements, whilst a second plurality of support elements, conveniently differing in number from the first plurality by 1, extend upwardly from intervening transverse elements.

In this way poultry may be mounted on the support elements in a "staggered" manner, allowing poultry to be mounted on the rack at a relatively high density, whilst preserving adequate space requirements between adjacent birds.

Preferably the support elements are constructed and arranged as to enable them to be located in an interior cavity of the foodstuff being cooked, e.g.

in the interior body cavity of poultry.

There will now be given a detailed description, to be read with reference to the accompanying drawings, of a poultry oven which is a preferred embodiment of the invention, which has been selected for the purposes of illustrating the invention by way of example, the oven utilising a rack, also illustrative of the invention in certain of its aspects, for conveying poultry through the oven.

In the accompanying drawings: Figure 1 is a schematic perspective view showing the rack; Figure 2 is an enlarged view showing part of the rack; Figure 3 is a side elevation of said rack. also showing a control device attached to the sensor probe; Figure 4 is a diagrammatic circuit view shc,wing the processing plant of which the preferred ernbodirnenr forms part; and Figure > is a schematic elevational view of the oven which is illustrative of this invention.

The rack utilised in the perforìilance of the invention comprises a frame 6, comprising a pair of spaced longitudinal frame elements 8, between which extend a plurality of transverse elements l(J. Support elements 12 extend upwardly from the transverse elements, being arranged alternately in two's and three's, so that poultry may be supported on the rack in a staggered manner, as is illustrated in Figure 4 of the drawings.

Each support element 12 is of inverted U-shape, and is inclined to the general plane of the frame 6, at an angle conveniently of between about 30 and about 600, allowing the support element to be inserted into an interior body cavity of the poultry. In addition each support element comprises holding means in the form of a transverse bar 13, beneath which the legs of the poultry may be inserted, more securely to retain it in position on the support element.

Inasmuch as the rack is formed of metal, and the support elements 12 extend into the body cavity of the poultry, they are effective to conduct heat into the interior body cavity, and contribute in part to the cooking of the poultry from the inside.

The rack comprises a temperature sensing device 14 comprising a probe 16 which may be inserted into poultry on the rack, the probe being connected to a housing of the device by a flexible connector 18, specifically to two outlet terminals 20, the voltage across which being proportional to the temperature sensed by the probe 16.

It is to be appreciated that whilst the rack shown in Figure 1 of the drawings illustrates seventeen support elements, a larger number both lengthwise and widthwise may be utilised, to convey a large number of birds through the oven on each rack. Desirably however, the numbers of spikes on alternating transverse rows differ by one, so that the birds mounted on the rack will be in "staggered" formation, increasing the uniformity of spacing between adjacent birds reducing the tendency for hot spots to form, and hence scorching of the skin ot the birds.

The oven which is the preferred embodiment of the invention comprises an elongate housing 30 provided with an inlet opening adjacent to t loading station 32 and an outlet opening which extends directly into a cooling device 33. The oven is designed as part of a cooking system, involving a continuous conveyor run extending through the oven, from a loading station adjacent to the inlet, through the cooling device 33 and to an unloading station 34 adjacent to the outlet, and through a washing station 35 at which the racks and the conveyor are cleansed, prior to returning to the loading station.

The oven comprises heating means, including fans and heating elements, conveniently in the form "thermal oil", electrically-heated elements, or direct gas fired, through which air is fed by the fans and passed over the poultry on the racks, as illustrated.

The floor of the oven is sloped towards a central well 44, wherein fat produced by the cooking of the poultry collects, pump means being provided to pump fat from the well and to cause the fat to be sprayed through spray nozzles 46 over the poultry, as it passes through a central region of the oven.

Provided at spaced intervals beneath the conveyor 36 are sensing elements in the form of flags 50, extending into the path of travel of the racks on the conveyor so as to engage the outlet terminaIs 20 of the sensing device 14. In this manner, as a rack passes each sensing element 50, the temperature sensed by the probe 16 thereof will be picked up by the element 50, cqnveniently for transmission to and displayed at a VDU located at a remote position. In this nzanller, the temperature attained by a selected bird as it passes through various stages in the oven may be plotted, and this may be compared with a desirable rest . to ensure that the poultry is properly cooked before it reaches the outlet.

In particular, the probe may be utilised to determine the position or location of any cold or hot spots within the oven, so that remedial action may be takeii.

In the use of the continuous system which is also illustrative of the invention, the conveyor 36 extends in the form of a continuous loop, passing through the oven 30, through the cooling device 33 and through the washing station 35. However the cooling device itself extends through a wall or other p,lrlition means 50, defining a sterile area, the conveyor exiting through a separate al)erlure in the partition 50, providing an unloading station which is relatively isolated from the washing station 35 and from uncooked poultry present at the loading station.

The oven 30 is divided into two zones, an initial zone A, and a final zone B. In zone A the temperature is maintained at a temperature of between 16() C and 1900C (dry bulb) and 65 C and 90 C (wet bulb), whilst in zone B the temperature is maintained between 1800C and 240 C (dry bulb) and 75 C and 90 C (wet bulb).

The poultry on the support elements are arranged in a backward inclination, i.e. are leaning rearwardly of the direction of travel through the oven.

In zone A the air flows against the direction of travel of the poultry through the oven, as indicated by the arrow A, while in zone B the air flows in the direction of travel of the poultry through the oven, as indicated by the arrow B.

On passage from the oven into the cooler, the poultry is taken through desired stages of chilling, during which the temperature of selected birds are measured by the probe 16, which engage with sensing elements 50 within the cooler, in the same manner as the temperature of the birds is measured during passage of the birds through the oven.

In this manner, poultry may be cooked and cooled at a very high through-put in a system which allows for accurate observ.ltioll and maintenance of temperature at varying stages of the birds through the treatment system, between the loading station and the unloading station.

Attention is drawn to the specification of UK Patent Application No.

8912819.3 (Serial No. 2232876) from which this applicatioll has been divided, and to Application No , also divided from said UK Patent Application.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific tornls or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or coinpositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof

Claims

CLAIMS: 1. An oven for the cooking of foodstuff, said oven having an inlet and an outlet, conveyor means extending between the inlet and outlet by which racks or trays containing the foodstuff may be conveyed through the oven, means to provide a controlled atmosphere in the oven, and means to sense temperature of the foodstuff as it is conveyed through the oven.
2. An oven according to Claim 1 comprising means to circulate heated air through the oven.
3. An oven according to Claim 2 wherein said circulation means is operative to deliver air into the oven so that the air flows rearwardly in the direction of passage of foodstuff through the oven.
4. An oven according to any one of the preceding claims wherein the oven forms parts of a closed circuit, comprising cooling means, and conveyor means extending from the cooler outlet to an unloading station, and then to a washing station at which the trays or racks are washed, prior to return to the loading station adjacent to the oven door.
5. In combination, an oven for cooking foodstuff and a rack upon which the foodstuff may be mounted, the oven comprising conveyor means to convey successive racks through the oven from an inlet to the outlet, each rack comprising temperature sensing means comprising a sensor probe which may be inserted into articles of foodstuff on the rack, and means by which the temperature sensed by each sensor probe may be determined as the rack passes through the oven.
6. The combination according to Claim 5 wherein the temperature sensed by each probe is determined continuously.
7. The combination a according to Claim 6 wherein the temperature is determined by a radio transmission system, and received by a remote receiver.
8. The combination according to Claim 5 wherein means is provided which is cooperable with the probe from time-to-time as it passes through the oven, by which the temperature sensed by the probe is determined.
9. The combination according to Claim 8 wherein the temperature sensing device comprises a control box, from which the probe extends, the control box comprising contact elements which may be engaged by sensing devices as the rack travels through the oven, an output from the sensing device relating to the output from the control box, and hence the temperature sensed by the probe.
10. The combination according to Claim 9 wherein the output from the sensing device is fed to a radio transmitter, to be picked up by a receiver and applied to a video display unit.
11. The combination according to Claim 9 wherein the output from the sensing device is fed to a video display unit by fixed wiring extending through the oven wall.
12. The combination according to any one of Claims 5 to 11 wherein a plurality of such sensing units are provided between the oven inlet and outlet with which each sensing box is from time-to-time cooperable as the racks pass through the oven.
13. The combination according to any one of Claims 5 to 12 wherein the oven comprises means operative in the event that the temperature sensed by the sensing devices falls below a predetermined level, to take some remedial action.
14. The combination according to any one of Claims 5 to 13, specifically for use in the cooking of meat, wherein the cooked meat passes from the oven into a cooling device, within which the meat is rapidly chilled, prior to passing to an unloading station.
15. The combination according to Claim 14 wherein the cooling device comprises means by which the temperature sensed by each sensor probe may be determined as the rack travels through the cooling device.
16. The combination according to Claim 15 wherein said means is similar to the means by which the temperature of the foodstuff is determined as it passes through the oven.
17. The invention according to any one of Claims 5 to 16, wherein each rack comprises a frame open-work construction, frame elements thereof supporting a plurality of upwardly-extending support elements.
18. The invention according to Claim 17 wherein the frame comprises two longitudinal frame elements and a plurality of transverse frame elements extending between the longitudinal elements.
19. The invention according to Claim 18 wherein the support elements extend upwardly from the transverse frame elements.
20. The invention according to any one of Claims 17, 18 and 19 wherein the support elements are generally of inverted U-shape.
21. The invention according to any one of Claims 17 to 20 wherein the support elements are inclined at an angle of 300 and 60".
22. The invention according to any one of Claims 17 to 21 wherein a first plurality of support elements extend upwardly from alternative transverse elements, whilst a second plurality of support elements extent upwardly from intervening transverse elements.
23. The invention according to Claim 22 wherein the first plurality of support elements differs in number from the second plurality by one.
24. The invention according to any one of Claims 5 to 23 wherein the support elements are constructed and arranged so as to enable them to be located in an interior cavity of the foodstuff being cooked.
25. The invention according to any one of the preceding claims, being adapted to cook poultry.
26. An oven for cooking foodstuff, constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.
27. In combination, an oven for foodstuff and a rack upon which the foodstuff may be mounted, constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.