GB2586992A

GB2586992A - Air impingement oven

Info

Publication number: GB2586992A
Application number: GB1913091.3A
Authority: GB
Inventors: Jackson Andrew
Original assignee: Lincat Ltd
Current assignee: Lincat Ltd
Priority date: 2019-09-11
Filing date: 2019-09-11
Publication date: 2021-03-17
Also published as: GB201913091D0

Abstract

An air impingement oven 1 comprising: upper and lower chambers 2, 3 provided with upper and lower air outlets and a horizontal movable support 4 between the upper and lower chambers for holding food during cooking. Heated air 6 ejected from the outlets impinges on the respective side of the support. The upper and lower air outlets are horizontally offset from one another. Preferably the upper and lower chambers comprise fans 12, 15 aligned with air inlets that are horizontally aligned with the air outlets of the opposing chamber and the chambers comprise heating elements 13, 14. Preferably the outlets are slits, holes or nozzles. Preferably the support is an air permeable rotating turntable that rotates about an axis and the lower air outlets and the upper and lower outlets are provided on opposite sides of the axis. The oven may comprise a closable chamber having sides 8, 9, 17 and a door which defines the front side. The upper and lower chambers may taper and consequently, the outer faces 20, 21 may be sloped

Description

Air Impinqement Oven The present disclosure relates to an air impingement oven.

Air impingement ovens are known in the prior art. These employ jets of heated air which are arranged to impinge against the surface of a food product that is moved relative to the jets during cooking. Figure 1 shows a typical arrangement of a prior art air impingement oven. An air box 100 is provided that defines upper and lower air outlet surfaces 101, 102 that are parallel to a conveyer 103 that supports a food product during cooking. Air that is heated by a heating element 105 exits the air box 100 via suitable openings in the upper and lower air outlet surfaces 101, 102 and impinges on the upper and lower surfaces of the food product supported by the conveyer. The heated air hits the food product perpendicular to the conveyer, is turned 90 degrees and is pulled back into a fan inlet 104, as indicated by the arrows in Figure 1.

Such an arrangement is ideally suited to the cooking of large solid products, such as pizzas. Consistent and even cooking is achieved. However, the oven is less well suited to the cooking of smaller items, such as sausages, chicken nuggets or chips.

The present invention arose in a bid to provide an improved impingement oven, better suited to the cooking of a range of differently sized food products, including smaller food products.

According to the present invention in a first aspect there is provided an air impingement oven comprising: an upper chamber provided with upper air outlets, a lower chamber provided with lower air outlets, and a support for supporting a food stuff during cooking, which is disposed between the upper and lower chambers, and is substantially horizontal during use, wherein heated air ejected from the upper air outlets impinges on an upper side of the support and heated air ejected from the lower air outlets impinges on an under side of the support, and the upper and lower air outlets are horizontally offset from one another, and wherein the support is movable such that a portion of the support is horizontally aligned with either the upper outlets or the lower outlets By such an arrangement, a smaller food product, such as a chicken nugget, a chip, or otherwise, which lies in the portion of the support is or chip is effectively impinged by hot air from above and impinged from hot air below asynchronously. This allows for consistent and even cooking.

Preferably the arrangement of the support and outlets is such that at any time during cooking every portion of the support is either impinged with hot air from above or below.

Preferably, the upper chamber comprises one or more upper air inlets, and the lower chamber comprises one or more lower air inlets, the upper air inlets being substantially horizontally aligned with the lower air outlets and the lower air inlets being substantially horizontally aligned with the upper air outlets. In other words, the one or more upper air inlets preferably overlap with the lower air outlets and the one or more lower air inlets preferably overlap with the upper air outlets.

By such an arrangement, it is possible to circulate the hot air out of the upper chamber through the one or more upper air outlets through the food product and into lower air inlets of the opposite lower chamber. This accelerated air can then be blown through the lower chamber out of the lower air outlets through the food product and into the one or more upper air inlets on the opposite upper chamber.

Such circular blowing of the air creates a very rapid airflow and aids in rapid and even cooking with the movement of food products through the airflows.

For accelerating the air, one or more fans are preferably provided. The one or more fans may comprise centrifugal fans.

To aid in airflow, it is preferable that the support is air permeable.

The arrangement of the fans and air inlets/outlets accelerates the airflow which breaks down the food products cold boundary layers more effectively than a conventional oven to give faster cooking times.

Temperatures, fan speeds and support movement speeds can all be varied to optimise cooking performance.

The support preferably comprises a rotating turntable. A complete rotation of the turntable will result in both sides of a food product being impinged with hot air.

The upper and/or lower outlets and/or inlets may define vents in vented upper/lower surfaces of a cooking chamber. The upper and lower chambers are preferably closed other than the outlets and inlets.

The upper and/or lower outlets and/or inlets may comprise slits or holes. The upper and/or lower outlets may alternatively comprise nozzles. Regardless of the arrangement of the outlets it is preferable that air is directed at substantially 90 degrees to an upper surface of the support.

There may be an upper fan provided in the upper chamber for drawing air into the upper chamber through the one or more upper air inlets and pushing it out of the upper air outlets. Additionally or alternatively, there may be a lower fan provided in the lower chamber for drawing air into the lower chamber through the one or more lower air inlets and pushing it out of the lower air outlets. Upper and lower fans are preferred for increased airflow although arrangements with a single fan will remain suitably effective.

The fans are preferably horizontally aligned with their respective one or more air inlets. The fan(s) located in this manner, i.e. behind the inlets, are highly efficient.

There may be a heating element provided in the upper chamber. Additionally or alternatively there may be a heating element provided in the lower chamber. Each of the one or more heating elements may surround an associated fan.

Either or both of the upper and lower chambers may be tapered to reduce in volume between the one or more air inlets and the air outlets. Such an arrangement can aid in increasing pressure and accelerating air from the outlets.

The oven preferably comprises a closable cooking chamber having, in use, upper, lower, front and back sides, wherein surfaces of the upper and lower chambers define the upper and lower sides, respectively, and a door is provided, which defines the front side. The door will provide access to the cooking chamber and close the cooking chamber during cooking.

Non-limiting embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a schematic representation of a prior art air impingement oven; Figure 2 shows a schematic representation of an air impingement oven according to the present invention; Figure 3 shows a partial sectional side view of an air impingement oven according to the arrangement of Figure 2 but with the lower fan and heating element omitted; and Figure 4 shows a perspective view of plates that define the upper and lower faces of a cooking chambers of the ovens of Figures 2 and 3 and form part of the upper and lower chambers, respectively.

With reference to Figures 2 to 4, there is shown an air impingement oven 1, which comprises an upper chamber 2, a lower chamber 3, and a support 4, which is substantially horizontal during use, for supporting a food stuff during cooking. The upper chamber 2 is provided with upper air outlets (5, Figure 4) and the lower chamber 3 is provided with lower air outlets (7, Figure 4). The support 4 is disposed between the upper and lower chambers 2, 3. Heated air 6 ejected from the upper air outlets 5 impinges on an upper side of the support (and thereby a food product supported thereby) and heated air 6 ejected from the lower air outlets 7 impinges on an under side of the support, as clearly indicated by the arrows in Figure 2. The upper and lower air outlets 5, 7 are horizontally offset from one another, as best seen in Figures 2 and 4. The support 4 is movable such that a portion of the support 4 is horizontally aligned with either the upper outlets or the lower outlets.

In the present arrangement, the support 4 comprises a rotating turntable, which is rotatable about an axis (as shown in broken lines in Figures 2 and 3). As discussed further below, in alternative arrangements, the support 4 may not comprise a turntable. It could be otherwise configured.

In the present arrangement, as best illustrated in Figure 2, the upper and lower outlets 5, 7 are preferably provided on opposed sides of the axis of rotation of the turntable. Taking the portion as a discrete region of the turntable on either side of the rotation of axis, it is clear that this will be horizontally aligned with the upper outlets 5 and the lower outlets 7 asynchronously by rotation of the turntable 4. The portion will thereby be impinged by hot air from above and below asynchronously with rotation of the turntable.

It is to be noted that the support is not limited to a turntable 4 or to the disclosed outlet arrangement. For example, in alternative arrangements, there could be a conveyer provided, with additional arrays of alternating upper and lower outlets 5, 7 along the length of the conveyer.

The air outlets are preferably arranged to that air is emitted at an angle of 90 degrees to an upper surface of the support 4.

The upper chamber 2 comprises one or more upper air inlets 10, and the lower chamber 3 preferably comprises one or more lower air inlets 11. The upper air inlets 10 are preferably substantially horizontally aligned (such there is some overlap) with the lower air outlets 7 and the one or more lower air inlets 11 are preferably substantially horizontally aligned (such there is some overlap) with the upper air outlets 5.

As discussed above, rapid and efficient circulation of hot air is possible with such an arrangement. The air circulation is indicated by the arrows in Figures 2 and 3. If the support 4 is air permeable, as is preferred, then airflow is further enhanced.

For accelerating the air, two fans are provided in the present arrangement.

An upper fan 12 is provided in the upper chamber 3 and a lower fan 13 is provided in the lower chamber. The fans may comprise centrifugal fans, as seen in Figure 3, however could be otherwise arranged/configured. Numerous different fan designs will be possible. Moreover, the fans could be otherwise located.

The fans are powered by electric motors 22, 23. The turntable is rotated by an electric motor 24.

The air may be heated by any suitable heating means. In the present arrangement, there is an upper heating element 14 that surrounds the upper fan 12 and a lower heating element 13 that surrounds the lower fan 15. There may in alternative arrangements be a single heating element. (As illustrated by Figure 3, which omits the lower heating element 13). Moreover, the heating elements could be otherwise located or formed, as will be appreciated by those skilled in the ad.

The oven preferably comprises a closable cooking chamber 16, which has in use, an upper side 8, a lower side 9, a left side 17, a right side (not shown), a front side 18 and a back side 19. As is clear from the Figures, inner surfaces of the upper and lower chambers define the upper and lower sides 8, 9, respectively, as is preferred. A door (not shown) is provided, which defines the front side 18.

In alternative arrangements, there need not be provided a closable cooking chamber. This may, in particular, be the case if the support comprises a conveyer.

The oven could be open at its front and/or rear.

In the present arrangement, in which the upper and lower outlets 5, 7 comprise slits, as best seen in Figure 4, the slits define perforations in plates that define the inner surfaces 8, 9 of the upper and lower chambers 2, 3. It is notable, as discussed, that the openings need not form slits and could take alternative forms and/or arrays than those shown.

In the present arrangement, the upper and lower inlets 10, 11 are also formed as perforations in the plates that define the inner surfaces 8, 9 of the upper and lower chambers 2, 3. As with the outlets 5, 7, the form of the inlets 10, 11 is not particularly limited. In the present arrangement a circular array of slits is provided for each inlet 10, 11, which is aligned with a respective one of the fans 12, 15. Notably, in alternative arrangements, a single opening could be provided for each inlet.

The upper and lower chambers 2, 3 are preferably closed other than the openings 5, 7, 10 and 11.

Either or both of the upper and lower chambers 2, 3 is preferably tapered to reduce in volume between the respective inlets and outlets, as shown in Figures 2 and 3. Such tapering may be effected, as in the present arrangement by sloped outer faces 20, 21 of the upper and lower chambers 2, 3.

Claims

Claims 1. An air impingement oven comprising: an upper chamber provided with upper air outlets, a lower chamber provided with lower air outlets, and a support for supporting a food stuff during cooking, which is disposed between the upper and lower chambers, and is substantially horizontal during use, wherein heated air ejected from the upper air outlets impinges on an upper side of the support and heated air ejected from the lower air outlets impinges on an under side of the support, and the upper and lower air outlets are horizontally offset from one another, and wherein the support is movable such that a portion of the support is horizontally aligned with either the upper outlets or the lower outlets.
2. An air impingement oven as claimed in Claim 1, wherein the upper chamber comprises one or more upper air inlets, and the lower chamber comprises one or more lower air inlets, the upper air inlets being substantially horizontally aligned with the lower air outlets and the lower air inlets being substantially horizontally aligned with the upper air outlets.
3. An air impingement oven as claimed in Claim 1 or 2, wherein the support comprises a rotating turntable.
4. An air impingement oven as claimed in Claim 3, wherein the turntable rotates about an axis and the upper and lower outlets are provided on opposed sides of the axis.5. An air impingement oven as claimed in any preceding claim, wherein the support is air permeable.
5. An air impingement oven as claimed in any preceding claim, which comprises a closable cooking chamber having, in use, upper, lower, front and back sides, wherein surfaces of the upper and lower chambers define the upper and lower sides, respectively, and a door is provided, which defines the front side.
6. An air impingement oven as claimed in any preceding claim, wherein the upper and lower outlets comprise slits, holes or nozzles.
7. An air impingement oven as claimed in Claim 2, or any claim dependent thereon, wherein an upper fan is provided in the upper chamber for drawing air into the upper chamber through the one or more upper air inlets and/or a lower fan is provided in the lower chamber for drawing air into the lower chamber through the one or more lower air inlets.
8. An air impingement oven as claimed in Claim 7, wherein the upper fan is horizontally aligned with one or more of the upper air inlets and/or the lower fan is horizontally aligned with one or more of the lower inlets.
9. An air impingement oven as claimed in Claim 8 or 9, wherein a heating element is provided in the upper chamber and/or a heating element is provided in the lower chamber.
10. An air impingement oven as claimed in Claim 2, or any claim dependent thereon, wherein the upper chamber is tapered to reduce in volume between the one or more upper air inlets and the upper air outlets and/or the lower chamber is tapered to reduce in volume between the one or more lower air inlets and the lower air outlets.