WO2018041633A1

WO2018041633A1 - An oven having a controlled exhaust system

Info

Publication number: WO2018041633A1
Application number: PCT/EP2017/070772
Authority: WO
Inventors: Bengul ASAR; Oguz TAN; Erol Karaer; Gulsun AKDEMIR EVRENDILEK; Gozde TASDEMIR
Original assignee: Arcelik Anonim Sirketi
Priority date: 2016-09-02
Filing date: 2017-08-16
Publication date: 2018-03-08
Also published as: TR201612515A2

Abstract

The present invention relates to an oven comprising an exhaust system (50) having a muffle (2) that limits a cooking chamber (6) in an accessible manner; a first exhaust opening (52) provided on the muffle (2), an air purification assembly (60) adapted to the first exhaust opening (52) so as to filter the exhaust gases sucked from the first exhaust opening (52) and an air discharge duct (55) to which the first exhaust opening (52) is connected so as to provide fluid connection to discharge the gas sucked from the first exhaust opening (52) and that is extended to a discharge zone (7). A second exhaust opening (54) is provided on the muffle (2) to selectively bypass the exhaust gas from the air purification assembly (60). A first damper (10) and a second damper (20) selectively block the first, respectively the second, exhaust opening.

Description

AN OVEN HAVING A CONTROLLED EXHAUST SYSTEM

Technical Field

The present invention relates to ovens wherein the exhaust gases formed in a cooking cavity during the cooking process are discharged by means of a fan in a controlled manner.

State of the Art

Domestic ovens comprise a cavity defining the cooking chamber and heater elements provided around the cavity. The foodstuffs placed into the cooking chamber diffuse various aromatic compounds during the cooking process. Depending on the type of food being cooked, some of the aromatic compounds diffused from some foodstuffs cause disturbance to the users. In order to eliminate this problem, odor filters are placed to the exhaust air passage to which the exhaust opening on a muffle defining the cooking chamber is connected.

The Patent Publication No. EP2093490 discloses a cooking oven comprising a cooking cavity and an exhaust gas purification assembly comprising a self-heated filter element comprising a gas-permeable, electrically conductive silicon carbide material and a current supply structure. The purification assembly comprises a self-heated filter element having a foam silicon carbide structural element.

The Patent Publication No. JPH05106854 discloses purification of odors and the like resulting from cooking of foodstuffs in ovens by means of an exhaust emission control device. Accordingly, a gas purification device wherein oily smoke, odor and the like generated as a result of the cooking process are cleared is placed to a first exhaust air passage through which the exhaust coming from the cooking chamber leaves the body of the cooking device without being cleaned and to a second exhaust air passage disposed parallel to the first exhaust air passage.

A first or second damper changing the exhaust exit path is provided, and the exhaust gas to be cleaned in the second air passage, coming from the cooking chamber, activates the catalytic heater.

Brief Description of the Invention

The aim of the present invention is to increase the efficiency of purification of the exhaust air discharged from the ovens having a controlled exhaust system.

In order to attain the said aim, the present invention is an oven comprising an exhaust system having a muffle that limits a cooking chamber in an accessible manner; a first exhaust opening provided on the muffle; an air purification assembly adapted to the first exhaust opening so as to filter the exhaust gases sucked from the first exhaust opening, and an air discharge duct to which the first exhaust opening is connected so as to provide fluid connection to discharge the gas sucked from the first exhaust opening and that is extended to a discharge zone. A preferred embodiment of the present invention comprises a second exhaust opening that is provided on the muffle and that is configured to open directly to the air discharge duct to selectively bypass the exhaust gas from the air purification assembly. The use of the first exhaust opening or the second exhaust opening depending on the type of the food cooked extends the lifespan of the purification assembly that filters the air leaving from the first exhaust opening, thus enabling the purification assembly to efficiently perform filtering process for a longer period of time. Moreover, when the user does not want that the odor of the product being cooked is filtered, he/she can selectively use the second exhaust opening and thus enable the exhaust gas in the cooking chamber to be directly discharged to the outer environment. Thus, for example, the odor of products such as cake or other pastries of which the aromatic odor is considered attractive is discharged to the outer environment while the exhaust gas having an oily and heavy odor, such as meat, fish, etc. is passed through the first exhaust opening and treated in the purification assembly.

In a preferred embodiment of the present invention, the air discharge duct extends close to the front edge of the muffle. Thus, the muffle can deliver the exhaust gas from the front part of a casing wherein the same is located to the outer environment. In built-in ovens wherein the casing is placed in a cabin, the formation of an additional air discharge assembly is not required. However, in alternative embodiments, the air discharge duct can be provided close to the rear edge of the muffle, on the base or ceiling, or even on the side wall thereof, so as to remain on the outer face.

A preferred embodiment of the present invention comprises a first damper positioned in the air discharge duct so as to selectively block the first exhaust opening. The damper enables the exhaust opening to be opened/closed in an adjustable manner. Thus, for example, by means of an electrical signal, a control element can fully close or open the first exhaust opening.

A preferred embodiment of the present invention comprises a second damper positioned in the air discharge duct so as to selectively block the second exhaust opening. In this case, both the first and second exhaust openings are selectively opened and closed in a controlled manner. For example, it is possible to discharge all the exhaust gas to the outer environment without being filtered by guiding the exhaust gas directly to the second exhaust opening by keeping only the first exhaust opening closed. Alternatively, by fully closing the second exhaust opening, it is possible to direct all the exhaust gas to the first exhaust opening so as to be filtered and discharged to the outer environment. Moreover, by fully closing both the first and second exhaust openings, moisture in the cooking chamber can be held in the cooking chamber at least for a certain time. The first damper or the second damper partially closes the corresponding first exhaust opening and/or second exhaust opening and thus enable the exhaust gas to be passed at different flow rates.

A preferred embodiment of the present invention comprises a bypass duct that opens to the air discharge duct by connecting the first exhaust opening to the second exhaust opening in air communication. Thus, a short discharge path is formed for the exhaust gas discharge and a compact structure is obtained.

A preferred embodiment of the present invention comprises a control element that is connected to the first damper and the second damper as a switch so as to transmit electrical signals and that adjusts the flow rate of the exhaust gas passing through the first exhaust opening and the second exhaust opening to the air discharge duct by transmitting the predetermined command to the first damper and the second damper depending on the type of the exhaust gas during the cooking process. In this case, the first or the second exhaust opening is opened to the discharge duct or completely/partially blocked by means of a predetermined program stored in a memory module or by selecting via a button on a control panel as desired. The control element can be a mechanical switch or a programmable processor.

A preferred embodiment of the present invention comprises a single-piece top plate attached to the muffle with a distance therebetween over a ceiling of the muffle so as to form the air discharge duct. The top plate forms a single-piece compact cover and thus both forms the discharge duct and forms a bearing that can receive the entire exhaust system.

A preferred embodiment of the present invention comprises a hollow body provided adjacent to the first exhaust opening of the air purification assembly and wherein a first filter element and at least a second filter element are fixed. By placing more than one filter element in the body, different filtration characteristics, e.g. filtering ratio, or retaining distinct aromatic compounds can be provided.

A preferred embodiment of the present invention comprises a heater that is provided in the body and that rises the temperature at least to a point that activates the first filter element or the second filter element. The heater provides that the catalytic filter elements are activated in a controlled manner when desired.

In a preferred embodiment of the present invention, the first filter element and the second filter element are adjacent to each other so as to provide heat transmission such that the heater heats the first filter element and the second filter element simultaneously. By means of the heat transmission, when the heater is operated, it is possible to activate simultaneously a plurality of filter elements with different filtration characters, but that can be activated by heat.

In a preferred embodiment of the present invention, the first exhaust opening is aligned coaxially with the first filter element and the second filter element. Thus, a compact filtration element is formed and the filtering efficiency is increased.

In order to attain the said aims, a preferred embodiment of the present invention comprises the operational steps of detecting the activation signal of the air purification assembly by means of the control element and adjusting the flow rate of the exhaust gas passing through the first damper to be transferred to the air discharge duct. The activation signal can be created by means of the cooking program preloaded in a memory module or can be generated by the control element based on the information of amount or type of smoke or odor sent from the cooking chamber by a smoke sensor or an electronic nose, for example.

In order attain the said aims, a preferred embodiment of the present invention comprises the operational steps of detecting the deactivation signal of the air purification assembly by means of the control element and adjusting the flow rate of the exhaust gas passing through the second damper to be transferred via the bypass duct to the air discharge duct. Thus, when the generation of unwanted odor or smoke in the cooking chamber decreases below a threshold value or is not present, the exhaust gas is guided directly to the second exhaust opening.

An oven realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

Figure 1 - is the perspective view of a representative embodiment of the muffle of an oven comprising the exhaust system of the present invention.

Figure 2 - is the cross-sectional view of a representative embodiment of the exhaust system of the present invention.

Figure 3 - is the detailed cross-sectional view of the damper of the exhaust system shown in Figure 2.

The elements illustrated in the figures are numbered as follows:

1 Casing

2 Muffle

5 Flange

6 Cooking area

7 Air discharge zone

8 Top wall

9 Opening

10 First damper

12 Cap

14 Arm

16 Motor

20 Second damper

22 Second cap

24 Second arm

26 Second motor

30 Fan assembly

32 Suction opening

50 Exhaust system

51 Upper part

52 First exhaust opening

53 Elevation

54 Second exhaust opening

56 Bypass inlet

58 Bypass outlet

59 Bypass duct

60 Air purification assembly

61 Heater

62 First filter element

63 Second filter element

64 Intermediate filter element

65 Inlet filter element

66 Air inlet

67 Body

70 Control element

Figure 1 is a perspective view of a muffle (2) that is disposed in a casing (1) of a household type oven and that limits a cooking chamber (6) so as to be accessible from the front, and of an exhaust system (50) provided on a ceiling (8) section of the muffle (2). By bending the muffle (2) outward along the border of the front edges thereof, a flange (5) is formed. A row of distanced openings (9) arranged at the same level along the upper edge of the flange (5) are formed. The openings (9) form the terminal end of an air discharge duct (55) that a top plate (51) covering the top of the muffle (2) forms between the ceiling (8) and the top plate (51) and thus enable the air discharged from the air discharge duct (55) to be discharged to the outside from a discharge zone (7) provided in the front. The top plate (51) rises like a truncated pyramid toward the center of the ceiling (8). At the center of the top plate (51), a first damper (10), a second damper (20) at a distance to the latter, and a fan assembly (30) that is disposed therebetween and that has a radial fan (34) are housed in a row.

Figure 2 is the schematic view of the connection of a control element (70) to the exhaust system (50) with a cross-sectional view. On the ceiling (8) of the muffle (2) a first exhaust opening (52) is disposed, that connects the cooking chamber (6) to the air discharge duct (55) so as to permit gas transmission. At the lower part of the first exhaust opening (52), an air purification assembly (60) extends toward the cooking chamber (6). The air purification assembly (60) is in the form of a hollow cylindrical body (67). An air inlet (66) is provided at the lower end of the body (67). The upper end of the body (67) is open and leak-proofingly surrounds the first exhaust opening (52) circumferentially. Moreover, a radial electric heater (61) is mounted on the air purification assembly (60) from the inside on the upper part of the body (67). The top plate (51) is drawn closer to the ceiling (8) of the muffle (2) by depressing the top plate (51) by means of a parallel lower plate (57) distanced to the top plate (51), corresponding to the first exhaust hole (52). Thus, the holes on the lower plate (57) and on the ceiling (8) together form the first exhaust hole (52). The lower plate (57) is leak-proofingly seated on the ceiling (8) circumferentially around the hole and enables all the exhaust gas to pass to the air discharge duct (55) that is provided between the lower plate (57) and the top plate (51). The first damper (10) comprises a motor (16) that extends in the vertical direction, an arm (14) that extends from the end of the motor (16) so as to enter the air discharge duct (55), and a cap (12) at the end of the arm (14), that is sized so as to completely cover the first exhaust hole (52) circumferentially from the top. The arm (14) is movable in the vertical direction. Similarly, a second damper (22) comprises a second motor (26), a second arm (24) connected to the second motor (26), and a second cap (22) at the free end of the second arm (24), that is sized so as to cover the second exhaust opening (54) circumferentially. The first damper (10) and the second damper (20) are structurally identical. The lower plate (57) is depressed to form the second exhaust opening (54) and joined to the muffle (2) from the ceiling (8). The lower plate (57) is circumferentially seated on the ceiling (8) at the depressed section and leak-proofingly connects the second exhaust opening (54) to the air discharge duct (55). The lower plate (57) is depressed for a second time and connects the first exhaust opening (52) and the second exhaust opening (54) to each other by forming a bypass duct (59). On the other hand, by completely blocking from the opposite edges, the lower plate (57) directly takes the exhaust has coming from the first or second exhaust opening (52, 54) into the bypass duct (59) through a bypass inlet (56) and a bypass outlet (58) so as to deliver to the air discharge duct (55). The radial fan (32) has access to the air discharge duct (55) through a suction opening (32). Thus, the radial fan (32) creates a constant vacuum on the first exhaust hole (52) or the second exhaust hole (54) and carries the exhaust gas provided therefrom to the discharge zone (7). A control element (70) connected to the front panel (not shown) of the oven is connected to the motor (16) and the second motor (26) via an electrical signal cable and provides the control of the first damper (10) and the second damper (20).

Figure 3 is a close-up view of the exhaust system (50) and the air purification assembly (60) connected thereto. An inlet filter element (65) is seated on the base of the cylindrical hollow body (67) above the air inlet (66). An intermediate filter element (64) is placed on the inlet filter element (65). A second filter element (63), circumferentially disposed on the body (67) from the inside, is disposed on the intermediate filter element (64), and at the uppermost position, a first filter element (63), seated on the second filter element (63) from the base thereof, is disposed. The heater (61) contacts the first filter element (62) from above.

Depending on the type of the food to be cooked it is decided whether the air purification assembly (60) will be activated automatically or manually by the user. If it is decided to activate the air purification assembly (60), the control element (70) sends a signal to the motor (16) and thus lifts the arm (14) and makes the corresponding first exhaust opening (52) of the cap (12) accessible to the air discharge duct (55). The fan (32) provides vacuum and thus enables the exhaust gas with unwanted aromatic compounds to be sucked from the air inlet (66) and passed through the filter elements (62, 63, 64, 65) in order. The heater (61) increases the first and the second filter elements (62, 63) to catalytic temperatures and thus provides that the exhaust gas is purified of the corresponding compounds while passing through the first and second filter elements (62, 63). The exhaust gas passes through the first exhaust opening (52) and reaches the air discharge duct (55) and therefrom delivered to the bypass duct (59) through the bypass inlet (56), thus moving through the discharge duct (55). Since the second damper (20) blocks the second exhaust opening (54), the purified exhaust air in the bypass duct (59) is prevented from returning to the cooking chamber (6). Alternatively, if it is decided not to activate the air purification assembly (60), or if no decision is made, the first damper (10) airtightly blocks the corresponding first exhaust opening (52). On the other hand, the second damper (20) is operated and the second motor (26) moves the second arm (24) upward while the second cap (22) makes the second exhaust opening (54) gas-accessible to the air discharge duct (55). The fan (34) creates vacuum and thus provides that the exhaust air is sucked from the cooking chamber (6) through the second discharge opening (54) and transferred to the air discharge duct (55). Consequently, the cooking exhaust air, that is not subjected to any filtration, is delivered from the discharge zone (7) to the outer environment.

Claims

An oven comprising an exhaust system (50) having a muffle (2) that limits a cooking chamber (6) in an accessible manner; a first exhaust opening (52) provided on the muffle (2); an air purification assembly (6) adapted to the first exhaust opening (52) so as to filter the exhaust gases sucked from the first exhaust opening (52), and an air discharge duct (55) to which the first exhaust opening (52) is connected so as to provide fluid connection to discharge the gas sucked from the first exhaust opening (52) and that is extended to a discharge zone (7), characterized by a second exhaust opening (54) that is provided on the muffle (2) and that is configured to open directly to the air discharge duct (55) to selectively bypass the exhaust gas from the air purification assembly (60).
An oven as in Claim 1, wherein the air discharge duct (55) extends close the front edge of the muffle (2).
An oven as in any one of the above claims, comprising a first damper (10) that is positioned in the air discharge duct (55) so as to selectively block the first exhaust opening (52).
An oven as in Claim 3, comprising a second damper (20) that is positioned in the air discharge duct (55) so as to selectively block the second exhaust opening (54).
An oven as in Claim 4, comprising a bypass duct (59) that opens to the air discharge duct (55) by connecting the first exhaust opening (52) to the second exhaust opening (54) in air communication.
An oven as in Claim 5, comprising a control element (70) that is connected to the first damper (10) and the second damper (20) as a switch so as to transmit electrical signals and that adjusts the flow rate of the exhaust gas passing through the first exhaust opening (52) and the second exhaust opening (54) to the air discharge duct (55) by transmitting the predetermined command to the first damper (10) and the second damper (20) depending on the type of the exhaust gas during the cooking process.
An oven as in any one of the above claims, comprising a single-piece top plate (51) attached to the muffle (2) with a distance therebetween over a ceiling (8) of the muffle (2) so as to form the air discharge duct (55).
An oven as in any one of the above claims, comprising a hollow body (67) provided adjacent to the first exhaust opening (52) of the air purification assembly (60) and wherein a first filter element (62) and at least a second filter element (63) are fixed.
An oven as in Claim 8, comprising a heater (61) that is provided in the body (67) and which rises the temperature to a point that activates at least the first filter element (62) or the second filter element (63).
An oven as in Claim 9, wherein the first filter element (62) and the second filter element (63) are adjacent to each other so as to provide heat transmission such that the heater (61) heats the first filter element (62) and the second filter element (63) simultaneously.
An oven as in Claims 8 to 10, wherein the first exhaust opening (52) is coaxially aligned with the first filter element (62) and the second filter element (63).
A control method for an oven as in Claim 5, comprising the operational steps of detecting the activation signal of the air purification assembly (60) by means of the control element (70) and adjusting the flow rate of the exhaust gas passing through the first damper (10) to be transferred to the air discharge duct (55).
A control method for an oven as in Claim 5, comprising the operational steps of detecting the deactivation signal of the air purification assembly (60) by means of the control element (70) and adjusting the flow rate of the exhaust gas passing through the second damper (20) to be transferred via the bypass duct (59) to the air discharge duct (55).