EP1913309A1

EP1913309A1 - A cooking device

Info

Publication number: EP1913309A1
Application number: EP06795644A
Authority: EP
Inventors: Levent Akdag; Haluk Karatas; Yalcin Yaman; Mehmet Marasli
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2005-08-12
Filing date: 2006-08-11
Publication date: 2008-04-23
Also published as: WO2007020587A1

Abstract

The present invention relates to a cooking device (1) wherein all the trays emplaced in the cooking chamber (3) are heated evenly by means of the effective and homogeneous heating of the cooking chamber (3).

Description

Description A COOKING DEVICE

[1] The present invention relates to a cooking device that provides the cooking process to be performed more effectively and more homogeneously.

[2] There is at least one heater and a fan in the cooking devices wherein the cooking process is employed by way of convection. The heater and the fan are situated between the cooking device framework and the rear wall of the cooking chamber. The air heated by the heater is activated by the fan and delivered into the cooking chamber by means of the holes formed on the rear wall and the food is cooked by the heat transfer created between the air and the foods to be cooked. However, the temperature of the air in the cooking chamber is higher near the heater and is lower in the distant parts. Furthermore, the front of the cooking device where its door is situated is in contact with the outer surroundings, and no matter how well insulated a door is utilized, this part near the door is colder than other parts of the cooking chamber. Problems are encountered in providing a homogeneous air distribution in the cooking chamber due to this and other similar reasons. In order to find a solution for this problem encountered in the cooking process, blowing holes are formed, being situated in various positions, having various shapes, sizes and numbers through which the air activated by the fan on the rear wall is blown into the cooking chamber and suction holes are formed through which the air delivered into the cooking chamber is aspirated.

[3] In state-of-the-art implementations, the suction holes are often positioned on the rear wall corresponding to the surface swept by the fan, and the blowing holes are positioned on the two sides of the suction hole groups. Since the blowing holes are on both sides of the fan, the air is blown through the blowing holes towards the side walls of the cooking chamber, not perpendicularly but with a certain angle. Accordingly, the air retaining a certain heat energy transfers its energy to the side walls instead of transferring it to the foods emplaced in the cooking chamber, resulting in a prolonged cooking time and an increase in the energy consumption.

[4] In order to overcome this kind of adversities, various implementations are designed in state-of-the-art.

[5] In state-of-the-art British Patent Application no. GB2054833, a heating apparatus is described. This heating apparatus comprises a rear wall having a number of suction apertures at the center and adjacent blowing apertures situated on the symmetrically formed projections.

[6] Another state-of-the-art document is the Japanese Patent Application no.

JP56074533. In this document, a rear wall having suction holes at the center and adjacent blowing holes situated on the symmetrically formed prismatic projections is described.

[7] In state-of-the-art United States Patent no. US4357522, the description is given for the air activated by an air blower that is directed to the outflow openings situated on the back wall by means of the air guide elements in a baking oven.

[8] In these state-of-the-art implementations, the air activated by the fan is blown through the holes on the rear wall of the cooking chamber, however, most of the hot air blown into the cooking chamber is aspirated again from the suction holes joining with the suction line before being dispersed throughout the cooking chamber and reaching the front part where heat loss is the greatest. In this way, since a short distance is traveled by the hot air blown from the blowing holes for a short period of time, the blown hot air is aspirated again before transferring the retained heat energy to the cooking chamber. Therefore, a homogeneous hot air distribution cannot be achieved in the cooking chamber and also the amount of energy necessary for heating the cooking chamber increases.

[9] The object of the present invention is to design a cooking device wherein an efficient cooking process is provided by the homogeneous air distribution in the cooking chamber.

[10] The cooking device designed to fulfill the objectives of the present invention, explicated in the first and the respective claims, comprises a rear wall that provides the distribution of almost all of the air throughout the cooking chamber and provides the air delivered into the cooking chamber to be blown without being dispersed until reaching the front part, up to the cooking device door where most of the heat loss occurs.

[11] The guide holes situated on the rear wall are positioned between the blowing holes that provide the air activated by the fan to be blown towards the suction line passing through the center of the cooking chamber and the section where the suction holes are situated. The guide holes provide air activated by the fan to be blown into the cooking chamber and also provide the air blown through the blowing holes into the cooking chamber to be guided towards the front part of the cooking chamber without being mixed in with the suction line. Consequently, the probability of the blown hot air in meeting with cold surfaces to transfer its retained heat energy is increased by extending the distance traveled and the time period that is necessary for transferring almost all of its retained heat energy is provided by being kept inside the cooking chamber.

[12] Since the guide holes and the blowing holes are positioned facing each other, providing the collision of the air exiting the guide holes and the blowing holes, the air blown from the guide holes and the air blown from the blowing holes form an air curtain on the suction line, providing the air flowing from the blowing holes directed towards the suction line to be diverted towards the front part of the cooking chamber without mixing in with the suction line.

[13] The guide and the blowing holes are of different shapes and numbers that are bored on flat or curvilinear surfaces formed with the formation of the rear wall. Almost all of the heat energy retained in the air activated by the fan can be transferred to the food inside the cooking chamber by means of the relative positions of the guide holes and the blowing holes, providing the reduction of cooking time and energy consumption.

[14] The deflectors on the guide and the blowing holes provide almost all of the hot air activated by the fan to reach the holes. Since the deflectors are formed on the back side of the rear wall and not on the front side, there are no protrusions on the surface of the rear wall where the user may contact. Therefore, the surface of the rear wall contacting the cooking chamber can be easily cleaned due to the positioning of the deflectors.

[15] There is a channel structure on the back side of the rear wall, one end of which extends to the area of the suction holes and the other end to the area of the blowing and the guide holes, providing the even distribution of the air activated by the fan to the trays emplaced in the cooking chamber. This channel structure is formed by shaping the rear wall without using any additional components.

[16] The channels provide the air activated by the fan to be equally distributed to the blowing holes and the guide holes positioned on the rear wall, situated on both sides of the fan.

[17] The blowing and guide holes can either be formed separately from the channels or can be formed on the channels by the shaping processes applied on the channels.

[18] The cooking device designed to fulfill the objectives of the present invention is shown in the attached figures, where:

[19] Figure 1 - is the side schematic view of a cooking device.

[20] Figure 2 - is the front view of a cooking device.

[21] Figure 3 - is the top view of a rear wall.

[22] Figure 4 - is the detailed back view of a rear wall.

[23] Figure 5 - is the detailed front view of a rear wall.

[24] Figure 6 - is the front view of a rear wall in an embodiment of the present invention.

[25] The elements shown in the figures are numbered as follows:

[26] 1. Cooking device

[27] 2. Exterior cabin

[28] 3. Cooking chamber

[29] 4. Rear wall

[30] 5. Heater

[31] 6. Fan [32] 7. Suction hole

[33] 8. Blowing hole

[34] 9. Guide hole

[35] 10. Deflector

[36] 11. Channel

[37] The cooking device (1) comprises an exterior cabin (2), a cooking chamber (3) positioned inside this exterior cabin (2) so that there is a gap in between them, one or more fans (6) for activating the air, situated between the cooking chamber (3) and the exterior cabin (2), one or more heaters (5) for heating the air, and a rear wall (4) that separates the cooking chamber (3) from the space where the fan (6) and the heater (5) are situated, providing to direct the air activated by the fan (6) (Figure 1 and Figure 2).

[38] The rear wall (4) comprises one or more suction holes (7) enabling the fan (6) to aspirate the air inside the cooking chamber (3), more than one blowing hole (8), situated between these suction holes (7) and the side walls of the cooking chamber (3), diverting the air activated by the fan (6) and providing it to be blown towards the center of the cooking chamber (3), and one or more guide holes (9) situated in between the area of the blowing holes (8) and the suction holes (7), positioned facing the blowing holes (8) with a certain angle, blowing the air towards the walls of the cooking chamber (3) by diverting it, colliding this air with the air exiting the blowing holes (8), preventing the air exiting the blowing holes (8) to be directed towards the suction line (Figure 3).

[39] Air is blown from the blowing holes (8) towards the center of the cooking chamber

(3). Air is blown from the guide holes (9) towards the side walls of the cooking chamber (3). As the blowing holes (8) provide to blow air into the cooking chamber (3), the guide holes (9) provide to direct the air blown from the blowing holes (8) to reach the front of the cooking chamber (3) without mixing in with the suction line.

[40] The suction holes (7) are situated on the rear wall (4) in the section corresponding to the surface swept by the fan (6). The suction holes (7) are formed on the rear wall (4) in various shapes, numbers and positions.

[41] The blowing holes and the guide holes (8 and 9) are preferably positioned symmetrically around the region where the suction holes (7) are situated at the center of the rear wall (4), surrounding this region.

[42] In the cooking device (1), when the heater (5) and the fan (6) are activated, as the heater (5) heats the air surrounding it, the fan (6) activates the air heated by the heater (5). The air activated by the fan (6) is blown into the cooking chamber (3) through the blowing holes (8) and the guide holes (9). The air exiting the blowing and the guide holes (8 and 9) collide inside the cooking chamber (3) due to their relative positions and the effect of the air blown from the blowing holes (6) towards the suction line is minimized due to the collision of the air blown from the guide holes (9) towards the side walls of the cooking chamber (3), the air exiting the blowing holes (8) and the guide holes (9) is directed towards the front of the cooking chamber (3). After the hot air directed towards the front of the cooking chamber (3) transfers its retained heat energy to the cold surfaces in the cooking chamber (3), and passes through the suction holes (7) by means of the suction force created by the fan (6), it is delivered to the area of the fan (6) to be blown through the blowing holes and the guide holes (8 and 9) again.

[43] In an embodiment of the present invention, the blowing holes (8) and the guide holes (9) are bored on surfaces that are on planes intersecting through a certain angle, being positioned opposite and partly facing each other formed by way of shaping the rear wall (4).

[44] In another embodiment of the present invention, the blowing holes (8) and the guide holes (9) are positioned on the sides of a "V" shaped recess formed by shaping the rear wall (4) so that they partly face each other.

[45] In another embodiment of the present invention, the blowing holes (8) and the guide holes (9) are positioned on the facing opposite planes of a convex surface formed on the rear wall (4) so that they partly face each other.

[46] In another embodiment of the present invention, the number of the blowing holes

(8) is more than the number of guide holes (9). Accordingly, most of the air activated by the fan (6) is blown through the blowing holes (8), the air blown from the guide holes (9) provide to only direct the air, preventing the air blown through the blowing holes (8) from mixing in with the suction line.

[47] In another embodiment of the present invention, the rear wall (4) comprises one or more deflectors (10) over each of the blowing and the guide holes (8 and 9) making a protrusion towards the side where the fan (6) is situated on the rear wall (4), positioned opposite the flow direction of the air, providing most of the air activated by the fan (6) to be effectively delivered inside the cooking chamber (3) through the blowing and guide holes (8 and 9) (Figure 4).

[48] In yet another embodiment of the present invention, the rear wall (4) comprises one or more channels (11), one end of which extends towards the area of the fan (6) and the other end towards the area of the blowing and the guide holes (8 and 9), providing the air activated by the fan (6) to be distributed homogeneously to the blowing and guide holes (8 and 9) and hence into the cooking chamber (3). In this embodiment, the channels (11) are positioned around the fan (6) so that they surround the periphery of the fan (6) radially and become horizontal as they approach the side walls of the cooking chamber (3), diverting the air flow. This channel (11) structure is formed by the shaping the rear wall (4) without using additional components (Figure 5 and Figure 6).

[49] In yet another embodiment of the present invention, the blowing and the guide holes (8 and 9) are formed on the channels (11). AU of the activated hot air between the exterior cabin (2) and the stepped rear wall (4) formed by means of the surfaces enabling the positioning of the blowing holes and the guide holes (8 and 9) so that they face each other, can be delivered through the blowing and the guide holes (8 and 9) into the cooking chamber (3).

[50] The number and structure of the blowing and the guide holes (8 and 9) on each channel (11) may be different for providing a homogeneous air distribution. Furthermore the channels (11) are formed to be in between each tray so that the trays emplaced in the cooking chamber (3) are effectively heated.

[51] By way of utilizing the rear wall (4) of the present invention, the homogeneous and effective heating of the cooking chamber (3) and the even heating of all the trays emplaced in the cooking chamber (3) is accomplished. By way of the present invention, the time period and the energy needed for the cooking process is reduced.

Claims

[1] A cooking device (1) comprising an exterior cabin (2), a cooking chamber (3) positioned inside this exterior cabin (2) such that there is a gap in between them, one or more fans (6) for activating the air, situated between the cooking chamber (3) and the exterior cabin (2), one or more heaters (5) for heating the air, and characterized by a rear wall (4) that separates the cooking chamber (3) from the space where the fan (6) and the heater (5) are situated, comprising one or more suction holes (7) enabling the fan (6) to aspirate the air from the cooking chamber (3), more than one blowing hole (8), situated between these suction holes (7) and the side walls of the cooking chamber (3), providing the air activated by the fan (6) to be blown by diverting towards the center of the cooking chamber (3), and one or more guide holes (9) situated in between the area of the blowing holes (8) and the suction holes (7), positioned facing the blowing holes (8) with a certain angle, blowing the air by directing towards the walls of the cooking chamber (3), colliding this air with the air exiting the blowing holes (8), preventing the air exiting the blowing holes (8) to be directed towards the suction line.

[2] A cooking device (1) as in Claim 1, characterized by a rear wall (4) comprising blowing holes and guide holes (8 and 9) positioned symmetrically around the region where the suction holes (7) are positioned.

[3] A cooking device (1) as in Claim 1 or 2, characterized by a rear wall (4) comprising blowing holes (8) and guide holes (9) that are bored on surfaces that are on planes intersecting through a certain angle, being positioned opposite and partly facing each other.

[4] A cooking device (1) as in Claim 1 or 2, characterized by a rear wall (4) comprising blowing holes (8) and guide holes (9) that are situated on the sides of a "V" shaped recess.

[5] A cooking device (1) as in Claim 1 or 2, characterized by a rear wall (4) comprising blowing holes (8) and guide holes (9) that are situated on a convex surface.

[6] A cooking device (1) as in any one of the above claims, characterized by a rear wall (4) comprising a number of blowing holes (8) that are more in number than the guide holes (9).

[7] A cooking device (1) as in any one of the above claims, characterized by a rear wall (4) comprising one or more deflectors (10) situated over each one of the blowing and the guide holes (8 and 9) forming a protrusion towards the side where the fan (6) is situated, positioned opposite the flow direction of the air, providing most of the air activated by the fan (6) to be delivered inside the cooking chamber (3) through the blowing holes and guide holes (8 and 9).

[8] A cooking device (1) as in any one of the above claims, characterized by a rear wall (4) comprising one or more channels (11), one end of which extends towards the region of the suction holes (7) and the other end towards the region of the blowing holes and the guide holes (8 and 9), providing the air activated by the fan (6) to be distributed homogeneously to the blowing holes and the guide holes (8 and 9).

[9] A cooking device (1) as in Claim 8, characterized by a rear wall (4) comprising channels (11), that are positioned around the fan (6) so that they surround the periphery of the fan (6) radially and become horizontal as they approach the side walls of the cooking chamber (3) for directing the air flow.