EP1966543B1

EP1966543B1 - Oven with sensor

Info

Publication number: EP1966543B1
Application number: EP06841586A
Authority: EP
Inventors: Murat Gundogdu; Cemalettin Kalayci
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2005-12-30
Filing date: 2006-12-21
Publication date: 2011-10-12
Anticipated expiration: 2026-12-21
Also published as: WO2007077160A2; EP1966543A2; ES2371665T3; WO2007077160A3; ATE528592T1

Abstract

The present invention provides sensors (7) that detect and measure parameters such as gas amount, humidity etc. inside the cooking chamber (4) with high operational temperatures, to be situated in the oven (1) in a position that allows them to make the most accurate detection and measurement without being affected by the high temperature.

Description

The present invention relates to an oven wherein sensors perform effective detection and measurement.
The temperature of the cooking chamber during the operation of the oven is much higher than the temperature of the ambient environment wherein the oven is located. In particularly the pyrolytic type ovens, the temperature of the cooking chamber is quite high. Therefore, particularly the sensors for humidity, gas etc. having much lower operational temperatures than the high temperatures of the cooking chamber cannot be used inside the cooking chambers. The use of sensors in ovens is very limited since the operational temperature values of the sensors are not suited for oven operational conditions. For example, since the existing humidity sensors are damaged by heat and humidity, they cannot be emplaced in the oven for detecting and controlling the humidity value of the high temperature air in the oven.
In order to prevent such adversities, heat sensors resistant to high temperatures have been designed. But this type of sensors designed to withstand high temperatures cannot be used in ovens having operational temperatures that can exceed 200° C.
In the current state of the art, the gases that are generated in the cooking chamber are mixed with the cold air from the outer environment in a ventilation channel and is delivered to the gas and/or humidity sensor after the temperature is lowered. In this implementation, since the gases will change depending on the features of the exterior environment, the gases in the cooking chamber cannot be measured accurately. Therefore, the data received from the sensor does not exactly reflect the conditions inside the oven.
In the German Patent Application no. DE4239334 , a ventilation channel to detect the pollution in an oven, another channel extending into the ventilation channel, having a thinner cross section than this channel and a gas sensor located at the closed end of this second channel are described. The sensor is situated at a higher level than the orifice of the second channel extending into the Ventilation channel so that the condensed fat and oil in the air flow do not reach the sensor. Consequently, the sensor can detect the humidity and/or the gases of the air cleansed of the condensed fat and oil particles.
In state-of-the-art European Patent Application no. EP0148162 , how the air activated by the fan for cooling the magnetron is passed over the sensor for cooling the sensor in a microwave oven is explained. Since the operational temperatures of state of the art microwave ovens are lower than other conventional ovens, the sensors can be easily implemented in the microwave ovens.
Document EP0504555 discloses further relevant prior art.
The object of the present invention is the realization of an oven comprising humidity, gas etc. sensors positioned at a place such that they will not be affected by the high temperatures in the cooking chamber and will make reliable measurements.
The oven realized in order to fulfill the objectives of the present invention, described in the first claim and dependent claims thereof, comprises a sensor chamber that opens directly to the cooking region and a ventilation channel wherein this sensor chamber is disposed, cooling this sensor chamber.
There are fins formed of various helical or quadrilateral geometric shapes over the sensor chamber in order to increase the heat transfer.
In pyrolytic type ovens, in the pyrolytic stage, that is when the cooking ends and pyrolytic cleaning begins at high temperatures, the sensor chamber and the sensors should preferably be automatically isolated in order to protect the sensors.
The oven realized in order to fulfill the objectives of the present invention is illustrated in the attached figures, where:
Figure 1- is the perspective view of an oven.
Figure 2 - is the schematic side view of the oven.
Figure 3 - is the perspective view of the sensor chamber in an embodiment of the present invention.
Figure 4 - is the perspective view of the sensor chamber in another embodiment of the present invention.
Figure 5 - is the schematic front view of the oven in an embodiment of the present invention.
Elements shown in figures are numbered as follows:

1.: Oven
2.: Body
3.: Chimney
4.: Cooking chamber
5.: Door
6.: Ventilation channel
7.: Sensor
8.: Sensor chamber
9.: Fan
10.: Air inlet
11.: Suction line
12.: Air outlet
13.: Discharge line
14.: Separator
15.: Fin
16.: Shutter

The oven (1) of the present invention comprises a body (2), a cooking chamber (4) situated inside the body (2), wherein the items to be cooked are emplaced, a door (5) separating the cooking chamber (4) from the exterior environment, providing access of the user into the cooking chamber (4), a fan (9) providing air circulation around the cooking chamber (4), a ventilation channel (6) situated between the body (2) and the cooking chamber (4), partly encircling the cooking chamber (4), wherein the fan (9) is arranged, providing to aspirate air from the door (5) or the exterior environment and after the aspirated air is circulated in the cooking chamber (4) discharging into the exterior environment again, a sensor (7) that detects and measures the parameters like gas, humidity etc. in the cooking chamber (4), and a sensor chamber (8) opening into the cooking chamber (4), wherein the sensor (7) is placed, extending from the cooking chamber (4) towards the inside of the ventilation channel (6), the air circulating in the ventilation channel (6) passing over its outer wall and hence providing the sensor (7) to directly measure the gas, humidity etc. parameters in the cooking chamber (4) without being affected by the high temperature (Figure 1, Figure 2 and Figure 5).
The oven (1) furthermore comprises a suction line (11) having an air inlet (10) for the entry of the air aspirated from the exterior environment or the door (5), a discharge line (13) having an air outlet (12) through which the air passing from the suction line (11) is discharged to the exterior environment, providing the flow of air discharged to the exterior environment and a separator (14) that separates the suction line (11) from the discharge line (13). The sensor chamber (7) extends in the ventilation channel (6) between the suction line (11) and the discharge line (13), intersecting through the separator (14). In this embodiment, the air aspirated from the exterior environment or the door (5) that is cooler than the cooking chamber (4) enters from the air inlet (10), flows along the suction line (11) and passes through the discharge line (13) by means of the fan (9) and is discharged from the air outlet (12) to the exterior environment. The sensor chamber (8) is cooled by the air circulated in the ventilation channel (6) through the suction and the discharge lines (11 and 13). Cooling the outer wall of the sensor chamber (8), particularly the upper portion of the sensor chamber (8) wherein the sensor (7) is positioned, by the air circulated in the discharge line (13) of the ventilation channel (6), provides the sensor (7) not to be affected by the temperatures higher than its operational conditions. For example, when the portion of the sensor chamber (8) opening into the cooking chamber (4) has the value of 280° C, its portion in the ventilation channel (6) that corresponds particularly to the discharge line (13) has a colder temperature value. In this embodiment of the present invention, the sensor (7) is situated in the upper portion of the sensor chamber (8) extending into the discharge line (13).
In another embodiment of the present invention, the sensor chamber (8) comprises one or more fins (15) situated on its outer wall, extending into the ventilation channel (6), increasing its surface area in contact with air (Figure 3). Consequently, the air circulating in the ventilation channel (6) impinges on these fins (15) and provides to cool the sensor chamber (8) and the sensor (7) situated in the sensor chamber (8) and not to be affected by the high temperature in the cooking chamber (4).
In yet another embodiment of the present invention, the fins (15) have a helical shape (Figure 4).
In another embodiment of the present invention, the oven (1) comprises a shutter (16) disposed in the sensor chamber (8) that opens or closes depending on the temperature of the cooking chamber (4). When the temperature of the cooking chamber (4) reaches a predetermined temperature value, the shutter (16) is closed, preventing the hot gases to reach the sensor (7), providing the sensor (7) not to be affected by the high temperature in the cooking chamber (4). When the temperature inside the cooking chamber (4) drops to a level lower than a predetermined temperature value, the shutter (16) is opened, allowing the gases in the cooking chamber (4) to reach the sensor (7), providing the sensor (7) to carry out its function properly.
In this embodiment of the present invention, the shutter (16) closes the sensor chamber (8) in high temperatures, providing to isolate the sensor (7) situated in the sensor chamber (8) and thus protects the sensor (7) from high temperatures.
In another embodiment of the present invention, the oven (1) comprises a chimney (3) that extends from the cooking chamber (4) to the ventilation channel (6). In this embodiment of the present invention, the sensor chamber (8) is situated in the ventilation channel (6) between the chimney (3) and the fan (9).
In another embodiment of the present invention, the chimney (3) is between the sensor chamber (8) and the fan (9).
In this embodiment, since the sensor chamber (8) is situated prior to the chimney (3), it is protected from the effect of the hot gases emitted through the chimney (3) and is less affected by the high temperature. In another embodiment of the present invention, the sensor chamber (8) is preferably made of metal; it can also be produced of a plastic material resistant to high temperatures.
By way of the present invention, the sensors (7) that detect and measure parameters such as gas amount, humidity etc. inside the cooking chamber (4) with high operational temperatures, are provided to be situated in the oven (1) in a position that will allow making the accurate detection and measurement without being affected by the high temperature. Furthermore, cost advantage is incurred since the use of high cost sensors with increased resistance to heat is deemed unnecessary.

Claims

An oven (1) comprising a body (2), a cooking chamber (4) situated inside the body (2), wherein the items to be cooked are placed, a door (5) separating the cooking chamber (4) from the exterior environment, providing access of the user into the cooking chamber (4), a fan (9) providing air circulation around the cooking chamber (4), a ventilation channel (6) situated between the body (2) and the cooking chamber (4), partly encircling the cooking chamber (4), wherein the fan (9) is arranged, providing to aspirate air from the door (5) or the exterior environment and after the aspirated air is circulated in the cooking chamber (4) discharging into the exterior environment again, a sensor (7) that detects and measures parameters such as gas amount, humidity etc. inside the cooking chamber (4), a sensor chamber (8), opening into the cooking chamber (4), into which the sensor (7) is placed, extending from the cooking chamber (4) towards the inside of the ventilation channel (6), the air circulating in the ventilation channel (6) passing over its outer wall and hence providing the sensor (7) to directly measure parameters such as gas amount, humidity etc. inside the cooking chamber (4) without being affected by the high temperature and characterized by a suction line (11) having an air inlet (10) for the entry of the air aspirated from the exterior environment or the door (5), a discharge line (13) having an air outlet (12) through which the air passing from the suction line (11) is discharged to the exterior environment, providing the flow of the air discharged to the exterior environment and a separator (14) that separates the suction line (11) from the discharge line (13), the sensor chamber (8), that extends in the ventilation channel (6) from the suction line (11) to the discharge line (13) by crossing the separator (14) for cooling the outer wall of the sensor chamber (8) by the air circulated in the ventilation channel (6) through the suction and discharge lines (11, 13).
An oven (1) as in Claim 1, characterized by the sensor (7) positioned in the upper portion of the sensor chamber (8) that extends towards the discharge line (13).
An oven (1) as in any one of the above claims, characterized by the sensor chamber (8) comprising one or more fins (15), extending from its outer wall into the ventilation channel (6), increasing its surface area in contact with air.
An oven (1) as in Claim 3, characterized by the sensor chamber (8) comprising a helical shaped fin (15).
An oven (1) as in any one of the above claims, characterized by a shutter (16) placed in the sensor chamber (8) that can open or close depending on the temperature of the cooking chamber (4).
An oven (1) as in any one of the above claims, characterized by a chimney (3) extending from the cooking chamber (4) to the ventilation channel (6) and the sensor chamber (8) that is situated in the ventilation channel (6) between the chimney (3) and the fan (9).
An oven (1) as in any one of the claims 1 to 5, characterized by the chimney (3) that is situated between the sensor chamber (8) and the fan (9).