WO2024253522A1

WO2024253522A1 - An apparatus and method for air frying food products

Info

Publication number: WO2024253522A1
Application number: PCT/NL2024/050288
Authority: WO
Inventors: Marcelina's Adrianus Maria OKKERMAN
Original assignee: Qbtec B.V.
Priority date: 2023-06-05
Filing date: 2024-06-05
Publication date: 2024-12-12
Also published as: NL2034999B1

Abstract

An apparatus and method for air frying food products. The hot air fryer comprises an air flow circuit. The air flow circuit comprises a frying chamber having an air flow inlet and an air flow outlet. The air flow circuit further comprises a heater and a pump. The heater is configured for heating air in the air flow circuit. The pump is configured for flowing heated air through the frying chamber. The air fryer further comprises a rotatable basket for receiving food products. The basket is positioned in the frying chamber and is rotatable around an axis of rotation. The air fryer further comprises a motor for rotating the basket. A centerline of the air flow inlet is offset with respect to the axis of rotation.

Description

Title: An apparatus and method for air frying food products

FIELD OF THE INVENTION

The present invention relates to the field of frying food products. In particular, the invention relates to the field of hot air frying food products. More in particular, the invention relates to a hot air fryer and a method for air frying food products.

BACKGROUND

It is known to deep fry food products by dipping them in deep-frying fat and/or oil. As a result, on the outside of the food products a crispy crust is formed. Nowadays, hot air fryers wherein fat and/or oil can be added by a user are gaining popularity for at-home usage. Unfortunately, the existing hot air fryers are not suitable for catering industry applications because of the low throughput rates. For employees of restaurants, and in particular snack bars and cafes, frequently reloading the hot air fryer with relatively small amounts of food products is cumbersome and labour intensive. Particularly during peak hours, such as around dinner time, existing at-home usage air fryers cannot meet catering consumer demand.

SUMMARY

It is an object to provide a hot air fryer and a method for air frying food products. More in general, it is an object to provide an improved hot air fryer and/or method for air frying food products.

Thereto, according to a first aspect is provided a hot air fryer. The hot air fryer comprises an air flow circuit. The air flow circuit can be at least partially enclosed by a conduit network. The air flow circuit comprises a frying chamber having an air flow inlet and an air flow outlet. The air flow inlet and air flow out can comprise separate components attached to a frying chamber main part. The air flow inlet and air flow outlet can also be integral with the frying chamber main part. The air flow circuit further comprises a heater for heating air in the air flow circuit. The heater can comprise one or more heating elements. The heater can be positioned in the air flow circuit, optionally located inside the conduit network. The heater can also be positioned at or near the air flow circuit, e.g. integral with a side wall of the conduit network. The air flow circuit comprises a pump for flowing heated air through the frying chamber. The pump can comprise a fan. The pump can comprise a centrifugal pump. The air flow circuit includes a main air flow path including the pump, the heater and the frying chamber. The main air flow path can extend from the pump, via the heater and via the frying chamber back to the pump. Hence, the air flow circuit, in particular the main air flow path, defines a closed loop of air flow through the pump, heater and frying chamber.

The hot air fryer further comprises a rotatable basket for receiving food products. The basket can rotate over more than 360°. The basket can e.g. rotate infinitely. A wall, in particular a circumferential wall, of the rotatable basket can comprise an air-permeable grid. The grid can comprise holes through which air can flow in and out. The grid can comprise a mesh, such as a metal mesh, e.g. stainless steel. The rotatable basket can comprise one or more openings for placing food products in the basket and/or for taking food products out of the basket. The one or more openings can be provided in an end wall of the basket. The one or more openings can be provided in the circumferential wall of the basket. The basket can comprise one or more doors for allowing the one or more openings to be opened and closed as desired. The circumferential wall of the basket can comprise the air- permeable grid along substantially the entire circumference, so that air can flow in and out of the basket regardless of a rotational position of the basket. The rotatable basket can be movably, such as slidably, positioned in the frying chamber, such that the rotatable basket can be moved in and out of the frying chamber. Food products can e.g. enter and/or exit the rotatable basket when it is positioned away from the frying chamber. The food products can be put in and/or taken out of the rotatable basket by a user or automatically. Optionally, the rotatable basket can be removed from the hot air fryer during loading and/or unloading of food products.

The rotatable basket is positioned in the frying chamber, and the basket is rotatable around an axis of rotation. The axis of rotation can be substantially horizontal. The frying chamber can comprise a substantially cylindrical shape. It will be appreciated that the frying chamber can have a different shape. The frying chamber is larger than the rotatable basket. The centre of the frying chamber can coincide with the axis of rotation of the rotatable basket. It will be appreciated that the axis of rotation of the rotatable basket can be offset with respect to the centre of the frying chamber. The hot air fryer comprises a motor for rotating the rotatable basket.

The rotatable basket can be at least partially positioned in the air flow circuit. The heated air can be moved by the pump through the rotatable basket. A centerline of the air flow inlet, such as a centerline of the air flow through the air flow inlet, of the frying chamber is offset with respect to the axis of rotation of the rotatable basket. The centerline of the air flow inlet of the frying chamber is e.g. offset with respect to the axis of rotation of the rotatable basket when a centerline of the air flow through the air flow inlet of the frying chamber is offset with respect to the axis of rotation of the rotatable basket, such as when the centerline of the air flow through the air flow inlet is offset with respect to the axis of rotation of the rotatable basket where the air flow impinges on the rotatable basket. The centerline of the air flow inlet of the frying chamber can be horizontally offset with respect to the axis of rotation of the rotatable basket. Hence, the air flow is aimed at the basket offset relative to the axis of rotation of the basket. This provides the advantage that the rotational movement of the food products in the rotating basket and the flow of air can optimally cooperate to fry the food products. Without wishing to be bound to theory, the inventors believe that offset provides that the food products are better exposed to the heated air flow than if the air flow were aimed at the axis of rotation. The centerline of the air flow inlet can be aimed at a side of the basket moving, in view of its rotation, in the same direction as the air flow. The centerline of the air flow inlet can be aimed at a side of the basket moving, in view of its rotation, in the opposite direction as the air flow. Although any amount of offset will provide a beneficial effect, it is noted that preferably the offset is larger than 10% of the radius of basket 10, more preferably larger than 25%, and preferably the offset is smaller than 90% of the radius of basket 10, more preferably smaller than 75%. The air flow inlet can at least partially be positioned vertically below the axis of rotation of the rotatable basket. The air flow inlet can be positioned asymmetric with respect to the axis of rotation. The air flow inlet can be positioned asymmetric with respect to the centre of the frying chamber. A centerline of the air flow inlet can be positioned offset with respect to a centerline of the air flow outlet. It will be appreciated that the air flow outlet can also be positioned offset with respect to the axis of rotation.

Optionally, the air flow circuit comprises a tapered part at or near the frying chamber air flow inlet. The tapered part can be positioned upstream of the air flow inlet of the frying chamber. The tapered part can be integral with the conduit network. The shape of the tapered part can be substantially convergent. The cross-sectional area of the tapered part can decrease in the direction of the air flow. In the conduit network, the tapered part can be formed by the local shape of the conduit part. Alternatively, the tapered part can be formed by an insert or one or more protrusions positioned in the air flow circuit. The downstream flow rate of air that exits the tapered part is higher than the upstream flow rate of the air flowing towards the tapered part. The pressure of the heated air upstream of the tapered part can be higher than the pressure of the heated air downstream of the tapered part.

Optionally, the heater is positioned in the air flow circuit between the pump and the basket. The air in the air flow circuit can flow from the pump to the heater and subsequently to the basket. Alternatively, the pump can be positioned in the air flow circuit between the heater and the rotatable basket. Then, the air in the air flow circuit can flow from the heater to the pump and subsequently to the basket.

Optionally, the pump is configured for moving the heated air vertically upward through the frying chamber air flow inlet. The air can be moved vertically upward by the pump through at least a part of the basket. Optionally, the air flow inlet is positioned vertically below the basket. The centerline of the air flow through the air flow inlet can be positioned substantially vertically, so that the heated air is blown substantially vertically upwardly through the basket. When the centerline of the air flow through the air flow inlet is positioned substantially vertically and the axis of rotation of the rotatable basket is substantially vertical, the centerline of the air flow through the air flow inlet can be horizontally offset with respect to the axis of rotation of the rotatable basket. Without wishing to be bound to theory, the inventors believe that blowing the heated air substantially vertically upwardly through the basket provides that the food products are better exposed to the heated air flow than if the air flow were aimed downwardly or horizontally. Also, stray food product parts, such as crumbs, can be blown out of the basket by the vertically upward flowing air.

Optionally, the basket comprises a substantially cylindrical shape. It will be appreciated that the rotatable basket can have a different shape, such as an ovoid shape or a truncated conical shape.

Optionally, the hot air fryer further comprises one or more nozzles for providing an atomized liquid or vapour to the air flow circuit. The nozzles can be positioned on the side of the air flow circuit. The nozzles can be integral with a side wall of the conduit network.

Optionally, the atomized liquid or vapour comprises water and/or cleaning fluid. The nozzles can be positioned close to a heating element of the heater. Atomizing water in the heated air flow can allow for generating steam for cleaning the hot air fryer.

Optionally, the hot air fryer further comprises a receptacle for capturing stray food product parts. The receptacle can comprise a tub and/or a bin.

According to a second aspect is provided a hot air fryer, e.g. a hot air fryer according to the first aspect. The hot air fryer comprises a conduit network providing an air flow circuit. The hot air fryer comprises a basket for receiving food products. The basket is at least partially positioned in the air flow circuit. The hot air fryer comprises a heater for heating air in the air flow circuit. The hot air fryer comprises a pump for moving heated air through the basket. The air flow circuit includes a main air flow path including the pump, the heater and the basket. The main air flow path can extend from the pump, via the heater and via the basket back to the pump.

The air flow circuit includes a curved portion. The curved portion can be integral with the conduit network. The conduit network includes a side duct branching off at the curved portion for directing the stray food product parts into the side duct. The side duct can branch off of the main air flow path at the outside bend of the curved portion. The side duct can be positioned aligned with or inclined with respect to a tangent of the curved portion. Stray food product parts carried along by the air flow can be directed into the side duct by centrifugal force at the curved portion. Hence, the stray food product parts can be separated from the main air flow path.

The curved portion can be positioned between the pump and the basket, so that the stray food product parts can be removed from the main air flow path before the main air flow path enters the basket.

Optionally, the hot air fryer further comprises in the side duct a first receptacle for receiving the stray food products. The first receptacle can be positioned at a distal end of the side duct.

Optionally, the first receptacle has a grid or filter in the bottom thereof. The density of the grid or filter can be configured to separate coarse and fine pieces of the stray food product parts. The density of the grid or filter can be configured to retain substantially all solid food product parts in the first receptacle, and to allow gas, such as air, and/or liquid to pass through the grid or filter.

Optionally, the hot air fryer comprises a second receptacle located vertically below the first receptacle. The second receptacle can receive the stray food particles or liquid that has fallen through the grid of the first receptacle.

Optionally, the hot air fryer comprises a bypass duct providing a bypass flow path from the side duct to the main air flow path. The bypass duct can extend from a first position to a second position. The first position can be in the side duct distal from a position where the side duct branches off of the main air flow path. The second position can be at a position on the main flow path. The second position can e.g. be downstream of a position where the side duct branches off of the main air flow path. The bypass duct can provide for an air flow through the side duct by at least partially preventing stagnant air preventing proper air flow through the side duct. The bypass duct can e.g. be in fluid communication with the side duct downstream of the first and/or second receptacle. Optionally, the hot air fryer further comprises a drain for draining liquid from the first and/or second receptacle. The drain can be connected to the second receptacle. The drain can comprise a valve for selectively blocking fluid flow in the drain.

Optionally, the first and/or second receptacle is removably positioned in the hot air fryer. The first and/or second receptacle can be removed from the hot air fryer during unloading of stray food product parts and/or during cleaning of the respective receptacles.

Optionally, the hot air fryer further comprises one or more nozzles for providing an atomized liquid or vapour to the air flow circuit.

Optionally, the air flow circuit comprises a tapered part upstream of the basket.

Optionally, the conduit network further comprises a frying chamber having an inlet and an outlet. The basket can be positioned in the frying chamber. The basket can be rotatable around an axis of rotation. A centerline of the air flow inlet can be offset with respect to the axis of rotation.

According to a third aspect is provided a method for air frying food products. The method comprises receiving food products in a basket. The basket can be a rotatable basket. The basket is at least partially positioned in a frying chamber. The basket is rotatable around an axis of rotation by a motor. The method can comprise rotating the basket. The method comprises heating air in an air flow circuit by a heater. The air flow circuit can at least partially be formed by a conduit network. The frying chamber is part of the air flow circuit. The method comprises providing heated air to the frying chamber using a pump. A centerline of air stream is directed at the rotatable basket. The centerline of the heated air stream is offset relative to the axis of rotation of the rotatable basket.

Optionally, the method further comprises locally increasing the flow rate of the heated air by providing a tapered part at or near an air flow inlet of the frying chamber.

Optionally, the method further comprises capturing stray food product parts in a receptacle. The method can comprise shooting stray food product parts out of the air flow circuit and into the receptacle by a curve in the air flow circuit. It will be appreciated that any of the aspects, features and options described in view of the hot air fryer apply equally to the method for air frying food products, and vice versa. It will also be clear that any one or more of the above aspects, features and options can be combined.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which:

Figure 1 shows an illustration of a schematic representation of an example of a hot air fryer;

Figure 2 shows an illustration of a schematic representation of an example of a front view of a part of an air flow circuit comprising a frying chamber;

Figure 3 shows an exemplary flow chart of a method for air frying food products; and

Figure 4 shows an illustration of a schematic representation of an example of a side view of a cross section of a hot air fryer.

DETAILED DESCRIPTION

Figure 1 shows an illustration of a schematic representation of an example of a side cross sectional view of a hot air fryer 1. The hot air fryer 1 comprises a conduit network 2 providing an air flow circuit 3 having a frying chamber 4, a heater 6 and a pump 8. The hot air fryer 1 further comprises a basket 10 and a motor 12 connected to the basket 10. In this example, the basket 10 comprises a rotatable basket. The basket can rotate over more than 360°. The air flow circuit 3 includes a main air flow path including the pump 8, the heater 6 and the frying chamber 4. In this example, the main air flow path extends from the pump 8, via the heater 6 and via the frying chamber 4 back to the pump 8.

Here, the frying chamber 4 is closed with a door 9 providing access to the inside of the frying chamber. In this example, the door 9 can move away, here slidably, from the frying chamber. The basket 10 can be connected to the door 9, such that opening the door positions the basket 10 outside the frying chamber for easy access. In this example, the basket 10 is substantially cylindrical. A longitudinal axis of the cylindrical basket 10 here coincides with an axis of rotation 14 of the basket. A circumferential wall 11 of the basket 10 comprises perforations for allowing air in. The circumferential wall 11 of the basket 10 can comprise the the perforations along substantially the entire circumference of the circumferential wall 11, so that air can flow in and out of the basket 10 regardless of a rotational position of the basket 10. Here, the circumferential wall is formed of a mesh, in particular a metal, such as stainless steel, mesh. The circumferential wall 11 here includes a lockable door 15. The door can be unlocked and opened for loading and unloading food product. In this example, the door also comprises a mesh. In this example, the basket comprises end walls 13, here circular end walls. At least one of the end walls can be mounted to an axle for rotation of the basket.

The frying chamber 4 has an air flow inlet 16 and an air flow outlet 18. Here, two nozzles 26 are positioned in the conduit network 2. It will be clear that a different number of nozzles 26 can be used, such as only one nozzle 26, or more than two nozzles 26, such as three, four, five, six, or eight nozzles. It will also be clear that the nozzle(s) 26 can be positioned differently in the conduit network, such as immediately upstream of the frying chamber 4. A part of the conduit network 2 is curved, thereby providing a curved portion 28 in the air flow circuit 3 in this example. Here, the conduit network 2 includes a side duct 30. The hot air fryer 1 further includes a first receptacle 32, a second receptacle 34, a drain 36 and a valve 38 in this example. The heater 6 is arranged for heating the air in the air flow circuit 3 inside the conduit network 2. It will be appreciated that the heater 6 can comprise a plurality of heating elements. The basket 10 is in this example at least partially positioned in the air flow circuit 3. The pump 8 is configured for moving heated air through the frying chamber 4. The heated air is also moved through the basket 10 by the pump 8. As the basket 10 can have perforations along the entire circumference of the circumferential wall 11, heated air can flow through the basket 10 regardless of the rotational position of the basket. Here, the pump 8 is configured for moving the heated air vertically upward through the air flow inlet 16 of the frying chamber 4. In Figure 1, the dashed arrows indicate the direction the air is flowing in the air flow circuit 3 when the pump 8 is active. Here, the heater 6 is positioned in the air flow circuit 3 between the pump 8 and the rotatable basket 10. It will be appreciated that the heater 6 can be positioned on the side of the conduit network 2, such as integrated in one or more conduit side walls. Alternatively, the pump 8 can be positioned in the air flow circuit 3 between the heater 6 and the rotatable basket 10.

Food products can be transferred into the rotatable basket 10 via the door 15 in the circumferential wall 11 thereof. The rotatable basket 10 can be movably positioned in the frying chamber 4, such that the rotatable basket 10 can move in and out of the frying chamber 4. The food products can be put in the rotatable basket 10 by a user when the rotatable basket 10 is positioned, at least partially, outside the frying chamber 4. It is also possible that the rotatable basket 10 can be removed from the hot air fryer 1, allowing for more efficient reloading of food products into the rotatable basket 10.

The air flow inlet 16 is in this example positioned vertically below the rotatable basket 10, and the air flow outlet 18 is positioned vertically above the rotatable basket 10. The heated air moving through the frying chamber 4 enters the rotatable basket 10, for heating the food products inside the basket. The rotatable basket 10 is positioned in the frying chamber 4, and is rotatable around the axis of rotation 14. The motor 12 is configured for, in use, rotating the rotatable basket 10 around the axis of rotation 14. The nozzles 26 are positioned in the conduit network 2 for providing an atomized liquid or vapour to the air flow circuit 3 in this example. It will be appreciated that there can be provided less or more nozzles 26, and the nozzles 26 can also be positioned close to the conduit network 2. The atomized liquid or vapour here comprise water and/or cleaning fluid. In this example, the nozzles 26 are configured for cleaning the conduit network 2. The nozzles 26 are in this example positioned vertically above the heater 6, for increasing ease of access of atomized liquid or vapour to the heater 6 for cleaning thereof and of the remainder of the air fryer.

The side duct 30 branches off of the main air flow path at the curved portion 28 of the conduit network 2 in this example. The curved portion 28 and the side duct 30 branching are here configured for directing the stray food product parts into the side duct 30. In this example, the first receptacle 32 is connected to the side duct 28 and is configured for capturing stray food product parts. The first receptacle can also be integral with the side duct 30 for receiving the stray food products. The stray food product parts can, in use, fall or be blown out of the basket 10 prior to being captured in the first receptacle 32. Here, the first receptacle 32 has a grid or filter in the bottom thereof. In this example, the grid or filter is configured to retain solid food product parts in the first receptacle 32, and to allow liquid to pass through the grid or filter into the second receptacle 34.

In this example, the hot air fryer 1 comprises a bypass duct 33. Here, the bypass duct 33 forms a bypass flow path extending from a first position at a distal end of side duct 30 to a second position on the main flow path. Here, the first position is downstream of the first and second receptacles 32, 34. It will be clear that the first position can be downstream of only the first receptacle 32, or upstream of the receptacles 32, 34. Here, the second position is downstream of a position where the side duct 30 branches off of the main air flow path. It will be clear that the second position can also be upstream of the position where the side duct 30 branches off of the main air flow path. The bypass duct 33 can provide for an air flow through the side duct 30 by at least partially preventing stagnant air preventing proper air flow through the side duct.

The second receptacle 34 is in this example located vertically below the first receptacle 32. The drain 36 is configured for draining liquid from the first receptacle 32 and/or the second receptacle 34. In this example, the drain 36 is connected to the second receptacle 34. Here, the drain 36 comprises a valve 38 for selectively blocking fluid flow in the drain 36. The first receptacle 32 and/or second receptacle 34 can be removably positioned in the hot air fryer 1. A user can therefore dispose the stray food product parts captured in the first and/or second receptacle 32, 34 by removing and subsequently emptying said receptacle.

Figure 2 shows an illustration of a schematic representation of an example of a front view of a part of the air flow circuit 3 comprising the frying chamber 4. The rotatable basket 10 is positioned in the frying chamber 4. In this example, the dashed arrows indicate the substantially vertically upward direction the air is flowing in the air flow circuit 3. Here, the frying chamber 4 and the rotatable basket 10 both have a substantially cylindrical shape. It will be appreciated that at least one of the frying chamber 4 and the rotatable basket 10 can have a different shape. The frying chamber 4 is larger than the rotatable basket 10. A centerline 20 of the air flow inlet 16 of the frying chamber 4 is offset

21 with respect to the axis of rotation 14 of the rotatable basket 10. More specifically, here a centerline 23 of the air flow through the air flow inlet 16, of the frying chamber 4 is offset with respect to the axis of rotation 14 of the rotatable basket 10. In this example, the centerline 23 of the air flow through the air flow inlet 16, of the frying chamber 4 is offset with respect to the axis of rotation 14 of the rotatable basket 10 where the air flow impinges on the rotatable basket 10. In this example, the position and direction of the air flow inlet 16, and the direction of the air flow through the air flow inlet 16, are static. Although any amount of offset will provide a beneficial effect, it is noted that preferably the offset is larger than 10% of the radius of basket 10, more preferably larger than 25%, and preferably the offset is smaller than 90% of the radius of basket 10, more preferably smaller than 75%. The air flow inlet 16 can at least partially be positioned vertically below the axis of rotation 14 of the rotatable basket 10. Here, the air flow inlet 16 is positioned asymmetric with respect to the axis of rotation 14 and the centre of the frying chamber 4. A centerline 20 of the air flow inlet 16 is positioned offset with respect to a centerline of the air flow outlet 18 in this example. It will be appreciated that the air flow outlet 18 can also be positioned offset with respect to the axis of rotation 14.

Here, the air flow circuit 3 comprises a tapered part 22. The tapered part

22 is positioned upstream of the air flow inlet 16 of the frying chamber 4 and is integral with the conduit network 2 in this example. The tapered part 22 ensures that the flow rate of air flowing out of the tapered part 22 will be higher than air flowing towards the tapered part 22. Hence, the tapered part 22 allows for a relatively high flow rate in the frying chamber 4. When the motor 12 is active, the rotatable basket 10 is rotating around the axis of rotation 14 thereof. Here, the rotatable basket 10 rotates in a direction of rotation 24 indicated by the curved arrow.

The direction of rotation 24 of the rotatable basket 10 is in this example substantially opposite to the flow direction of the heated air, indicated by the dashed arrows, at the air flow inlet 16 of the frying chamber 4. The rotatable basket 10, when rotating in the direction of rotation 24, moves the food products in the direction of an opposing heated air flow at the air flow inlet. The heated air flow at the air flow inlet opposing the direction of rotation 24 of the basket 10 provides increased air flow. A centerline 20 of the air flow inlet 16 being offset with respect to the axis of rotation 14 of the rotatable basket 10 combined with the rotational direction 24 and the direction of the heated air flow here allow for the direction of the heated air flow and the rotational direction 24 to be opposite at the frying chamber 4 air flow inlet 16.

Figure 3 shows an example of a flow chart of a method 100 for air frying food products. Optional steps are shown in dashed boxes. In a first step 102, the food products are received in an, e.g. rotatable, basket 10. The basket 10 is at least partially positioned in a frying chamber 4. The air in the air flow circuit 3 is heated by a heater 6 in step 104. The frying chamber 4 is part of the air flow circuit 3. Optionally, in step 106 the basket 10 is rotated. The basket 10 can be rotatable around an axis of rotation 14 by a motor 12. Heated air is provided to the frying chamber 4 using a pump 8 in step 108, wherein a centerline 20 of air stream is directed at the rotatable basket 10 offset relative to the axis of rotation 14 of the rotatable basket 10. The basket 10 can be rotated continuously, at least for a part of the time that heated air is provided to the frying chamber. Optionally, the flow rate of the heated air is increased locally in step 110 by providing a tapered part 22 at or near an air flow inlet 16 of the frying chamber 4. In step 112, stray food product parts can be captured in a first receptacle 32. The stray food product parts can be shot out of the air flow circuit 3 and into the first receptacle 32 by a curved portion 28 in the air flow circuit 3 in step 112.

Figure 4 shows an illustration of a schematic representation of an example of a side view of a cross section of a hot air fryer 1. In this example, the heater 6 comprises a plurality of, here three, heating elements. The heating elements of the heater 6 are in this example positioned horizontally offset with respect to each other. This allows for more efficient heat transfer, since the heater 6 is spread across the cross section of the air flow circuit 3. A nozzle 26 is positioned in the air flow circuit 3 formed by the conduit network 3 in this example. Here, the nozzle 26 is positioned vertically above the heating elements of the heater 6. The positioning of the nozzle 26 vertically above the heating elements allows for atomized liquid or vapour to be directed at the heater 6 for cleaning thereof and of the remainder of the air flow circuit. The pump 8 comprises a fan-type or impeller-type pump with volute casing in this example.

Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein, without departing from the essence of the invention. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged.

However, other modifications, variations, and alternatives are also possible. The specifications, drawings and examples are, accordingly, to be regarded in an illustrative sense rather than in a restrictive sense.

For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other features or steps than those listed in a claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to an advantage.

Claims

1. A hot air fryer, comprising: an air flow circuit comprising: a frying chamber having an air flow inlet and an air flow outlet; a heater for heating air in the air flow circuit; and a pump for flowing heated air through the frying chamber; the fryer further comprising: a rotatable basket for receiving food products, wherein the rotatable basket is positioned in the frying chamber, wherein the rotatable basket is rotatable around an axis of rotation; and a motor for rotating the rotatable basket; wherein a centerline of the air flow inlet is offset with respect to the axis of rotation.

2. The hot air fryer according to claim 1, wherein the air flow circuit comprises a tapered part at or near the frying chamber air flow inlet.

3. The hot air fryer according to claim 1 or 2, wherein the heater is positioned in the air flow circuit between the pump and the basket.

4. The hot air fryer according to claim 3, wherein the rotatable basket is rotatable in a direction substantially opposite to the flow direction of the heated air in the frying chamber air inlet.

5. The hot air fryer according to claim 4, wherein the pump is configured for moving the heated air vertically upward through the frying chamber air flow inlet.

6. The hot air fryer according to claim 5, wherein the air flow inlet is positioned vertically below the basket.

7. The hot air fryer according to any of the preceding claims, wherein the basket comprises a substantially cylindrical shape.

8. The hot air fryer according to any of the preceding claims, further comprising one or more nozzles for providing an atomized liquid or vapour to the air flow circuit.

9. The hot air fryer according to claim 8, wherein the atomized liquid or vapour comprises water and/or cleaning fluid.

10. The hot air fryer according to any of the preceding claims, further comprising a receptacle for capturing stray food product parts.

11. A hot air fryer, comprising:

- a conduit network providing an air flow circuit;

- a basket for receiving food products, wherein the basket is at least partially positioned in the air flow circuit;

- a heater for heating air in the air flow circuit;

- a pump for moving heated air through the basket; and

- a first receptacle for capturing stray food product parts; wherein the air flow circuit includes a curved portion, and the conduit network includes a side duct branching off at the curved portion for directing the stray food product parts into the side duct.

12. The hot air fryer according to claim 11, further comprising in the side duct a first receptacle for receiving the stray food products.

13. The hot air fryer according to claim 12, wherein the first receptacle has a grid in the bottom thereof.

14. The hot air fryer according to claim 12 or 13, comprising a second receptacle located vertically below the first receptacle.

15. The hot air fryer according to claim 12, 13 or 14, comprising a drain for draining hquid from the first and/or second receptacle.

16. The hot air fryer according to any of claims 12-15, wherein the first and/or second receptacle is removably positioned in the hot air fryer.

17. The hot air fryer of any of claims 11-16, comprising a bypass duct providing a bypass flow path from the side duct to a main air flow path.

18. The hot air fryer according to any of claims 11-17, further comprising one or more nozzles for providing an atomized hquid or vapour to the air flow circuit.

19. The hot air fryer according to any of claims 11-18, wherein the air flow circuit comprises a tapered part upstream of the basket.

20. The hot air fryer according to any of claims 11-19, wherein the conduit network further comprises a frying chamber having an inlet and an outlet, and wherein the basket is positioned in the frying chamber, wherein the basket is rotatable around an axis of rotation, and wherein a centerline of the air flow inlet is offset with respect to the axis of rotation.

21. A method for air frying food products, comprising: receiving food products in a rotatable basket, wherein the rotatable basket is at least partially positioned in a frying chamber, and wherein the rotatable basket is rotatable around an axis of rotation by a motor; heating air in an air flow circuit by a heater, wherein the frying chamber is part of the air flow circuit; and providing heated air to the frying chamber using a pump, wherein a centerline of the heated air stream is directed at the rotatable basket offset relative to the axis of rotation of the rotatable basket.

22. The method according to claim 21, further comprising locally increasing the flow rate of the heated air by providing a tapered part at or near an air flow inlet of the frying chamber.

23. The method according to claim 21 or 22, further comprising: capturing stray food product parts in a receptacle; and shooting stray food product parts out of the air flow circuit and into the receptacle by a curve in the air flow circuit.