WO2007049197A2

WO2007049197A2 - An oven

Info

Publication number: WO2007049197A2
Application number: PCT/IB2006/053853
Authority: WO
Inventors: Talip Caglar
Original assignee: Arcelik Anonim Sirketi
Priority date: 2005-10-25
Filing date: 2006-10-19
Publication date: 2007-05-03
Also published as: ATE542089T1; EP1941209A2; ES2380956T3; EP1941209B1; WO2007049197A3; PL1941209T3

Abstract

The present invention relates to an oven (1) wherein the cooking process is continued when the heater (2) is turned off while the fan (3) is operated at the end of the cooking time selected by the user and consequently the total operation duration of the heater (2) is reduced providing savings in the consumption of energy, since the residual heat in the oven is used for finishing cooking of the food.

Description

Description AN OVEN

[1] The present invention relates to an oven wherein energy saving is provided in the cooking process.

[2] In ovens, various cooking algorithms are utilized in order to provide an effective cooking and to use energy efficiently. In these implementations, usually the cooking time is adjusted by the user and when the cooking time entered by the user ends, the functioning of elements such as the heater and the fan are stopped. In order to keep the oven at the desired temperature value, the heater is operated on and off until the end of the cooking time, when the temperature of the heater reaches the upper limit value the heater is shut off, and when it reaches the lower limit value the heater is operated while the fan operates continuously in the course of the cooking duration in the oven (Figure 2). When the cooked food stays in the closed volume for a while longer at the end of the oven cooking time, the surface of the food may be burnt.

[3] In the European patent no. EP0628772, in an electric oven, a main heater, a fan, and lower and upper auxiliary heaters are provided, the fan is operated with the main heater during the first mode and the upper and lower heaters are operated with the fan during the second mode and the cycle is repeated during the overall cooking duration.

[4] In the Japanese patent no. JP59231331 in order to reduce the adverse effects due to the opening of a door during preheating, the control device measures the temperature in the heating chamber by a temperature sensor, turns on the heater relay if the temperature in the heating chamber is lower than the preheating control temperature and then feeds electric power to the electric heating device, if the temperature is higher than the preheating control temperature, the electric heater is not supplied with electrical energy and the circulation fan is turned on to have a homogeneous heat distribution in the heating chamber.

[5] In the Great Britain Patent no. GB2172990, a long-duration low-temperature cooking is made possible by retaining a constant moisture equilibrium in the oven.

[6] The aim of the present invention is the realization of an oven wherein savings in energy consumption is maintained by regulating the operation of the elements such as the heater and the fan.

[7] The oven realized in order to attain the aim of the present invention is explicated in the claims.

[8] In ovens, there is a distribution space behind the rear wall wherein the fan and the heater are situated, from where the hot air heated by the heater is delivered into the oven by means of the fan. In the current state of the art, a cooking time is set depending on the type of food to be cooked and this cooking time is saved in the memory by the user before starting to cook. The heater and the fan are operated according to the selected food type and the set cooking time, and the heater is usually operated intermittently while the fan is operated continuously until the end of the cooking time. In the embodiment of the present invention, at the end of the predetermined cooking time, the heater is turned off for some time while the fan is still operated; accordingly the cooking is continued with the residual heat left in the vicinity and surface of the heater in the distribution space for a little while longer. Since the heater is operated less than the time predetermined before cooking, hence saving in energy consumption is provided.

[9] In addition to the air blowing openings on the rear wall of the oven that provide to direct the hot air blown by the fan into the oven, there are auxiliary air blowing openings that are opened during the residual heat procurement duration in the embodiment of the present invention. The auxiliary air blowing openings are kept closed by shutters during most of the cooking time and towards the end of the cooking time when the heater is turned off, the auxiliary air blowing openings are opened by the shutters, providing the fan to blow an increased amount of hot air into the oven and taking more advantage of the residual heat in the distribution space in a short time period.

[10] The oven realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

[11] Figure 1 - is the schematic view of an oven.

[12] Figure 2 - is the operation - time graph of the heater and the fan in a state-of-the-art oven.

[13] Figure 3 - is the operation - time graph of the heater and the fan in the oven of the present invention.

[14] Figure 4 - is the graph of the temperature variation in the cooking chamber at the end of the cooking time in a state-of-the-art oven and the oven of the present invention.

[15] Figure 5 - is the front schematic view of a rear wall.

[16] Figure 6 - is the sideways schematic view of a rear wall and the distribution space.

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

[18] 1. Oven

[19] 2. Heater

[20] 3. Fan

[21] 4. Cooking chamber

[22] 5. Distribution space

[23] 6. Rear wall

[24] 7. Auxiliary opening

[25] 8. Opening [26] 9. Shutter

[27] The oven (1) comprises a heater (2) that heats the air in its vicinity, a fan (3) that activates the heated air, a cooking chamber (4) wherein the cooking process takes place, a distribution space (5) wherein the heater (2) and the fan (3) are situated, and a rear wall (6) that separates the cooking chamber (4) from the distribution space (5) and provides the hot air activated by the fan (3) in the distribution space (5) to be distributed homogeneously in the cooking chamber (4).

[28] The rear wall (6) comprises one or more air blowing openings (8) that allow the hot air blown by the fan (3) to be directed to the cooking chamber (4).

[29] In the oven (1) of the present invention, at the end of the total cooking time (t) selected by the user before cooking, the heater (2) is turned off for a time (tl) duration predetermined by the manufacturer, depending on the cooking times and/or temperatures that may be selected by the user, and the fan (3) continues operating during the time (tl) duration the heater (2) is turned off, the heat on the heater (2) and its vicinity is delivered from the distribution space (5) into the cooking chamber (4) (Figure 3). Since only the fan (3) operates while the heater (2) is turned off during the time (tl) duration at the end of the total cooking time (t), energy saving is maintained.

[30] When the time (tl) duration during which the fan (3) is operated while the heater

(2) is turned off ends, the fan (3) is stopped since the total cooking time (t) also ends at the same time.

[31] In the graph in Figure 4, the temperature variation curve (D) in the cooking chamber (4) in the case when the heater (2) and the fan (3) stop at the same time in the oven (1) and the temperature variation curve (E) in the cooking chamber (4) in the case when the heater (2) is turned off at a certain time (tl) prior to the completion of the pre-selected cooking time (t) while the fan (3) continues to operate until the end of the cooking time (t) are shown. In this example, the heater (2) is turned off at a certain time (tl) before the end of the cooking time (t) and the fan (3) continues operating after the heater (2) is turned off. As can be observed from the E curve, the cooking chamber (4) is kept at high temperature values such that cooking can be continued in the time (tl) period and cools off more rapidly after the time (tl) period ends.

[32] In an embodiment of the present invention, the time (tl) duration predetermined by the manufacturer is fixed. In this embodiment, whatever cooking time (t) and/or temperature are pre-selected before cooking, the heater (2) is turned off for a fixed time (tl) duration at the end of the total cooking time (t) and the fan (3) is continued to be operated until the cooking time (t) ends.

[33] In another embodiment of the present invention, the time (tl) duration predetermined by the manufacturer is variable. In this embodiment, the time (tl) duration predetermined by the manufacturer can be a certain percentage of the time (t) selected by the user before cooking starts. For example, if the time (tl) duration is determined by the manufacturer to be 10 % of the total cooking time (t), and the user selects the cooking time (t) as 45 minutes, then the heater (2) stops after operating for 40,5 minutes and only the fan (3) operates for the remaining 4,5 minutes.

[34] In an embodiment of the present invention, the oven (1) comprises one or more auxiliary openings (7) situated on the rear wall (6) that open only during the time (tl) duration while the heater (2) is turned off and the fan (3) operates, providing to increase the amount of hot air delivered by the fan (3) into the cooking chamber (4) and one or more shutters (9) that allow the opening closing of the auxiliary openings (7). In this embodiment, while the fan (3) continues operating when the heater (2) is turned off at a time (tl) before the cooking time (t) ends, the auxiliary openings (7) are opened simultaneously by the shutters (9) providing to deliver efficiently the heat in the vicinity of the heater (2) into the cooking chamber (4) and when the fan (3) is stopped at the end of the time (tl) duration, the auxiliary openings (7) are closed simultaneously by the shutters (9).

[35] In the oven of the present invention, the heat on the surface and in the vicinity of the heater (2) behind the rear wall (6) is delivered into the cooking chamber (4) for the course of a certain time (tl) period, without energizing the heater (2), only by operating the fan (3) at the end of the cooking time (t). The heater (2) operates less than the pre-selected cooking time (t) and energy saving is achieved. Furthermore, since almost all of the existing heat is used up in the cooking process at the end of the cooking time (t), the risk of burning the food that is kept in the cooking chamber (4) after cooking is reduced.

Claims

[1] An oven (1) comprising a heater (2), a fan (3) that activates the heated air, a cooking chamber (4) wherein the cooking process takes place, a distribution space (5) wherein the heater (2) and the fan (3) are situated, and a rear wall (6) that separates the cooking chamber (4) from the distribution space (5) providing the hot air in the distribution space (5) to be distributed homogeneously in the cooking chamber (4) and characterized by a heater (2) that is turned off at the end of the total cooking time (t) selected by the user prior to cooking, for a time duration (tl) predetermined by the manufacturer depending on the cooking times and/or temperatures that may be selected by the user and a fan (3) that continues to be operated in the time duration (tl) while the heater (2) is turned off providing the heat on the heater (2) and its vicinity to be delivered from the distribution space (5) into the cooking chamber (4).

[2] An oven (1) as in Claim 1, characterized by a heater (2) that is turned off at the end of the total cooking time (t) for a fixed time (tl) duration determined by the manufacturer.

[3] An oven (1) as in Claim 1, characterized by a heater (2) that is turned off at the end of the total cooking time (t) for variable time (tl) durations determined separately by the manufacturer according to the various cooking times (t) and/or temperatures selected prior to cooking.

[4] An oven (1) as in Claim 3, characterized by a heater (2) that is turned off at the end of the total cooking time (t) for a time (tl) duration that is a percentage of the total cooking time (t) selected by the user.

[5] An oven (1) as in any one of the above claims, characterized by stopping of the fan (3) when the time (tl) duration ends during which the heater (2) is turned off while the fan (3) is operated, since the total cooking time (t) also ends at the same time.

[6] An oven (1) as in any one of the above claims, characterized by one or more auxiliary openings (7) situated on the rear wall (6) that open during the time (tl) duration while the heater (2) is turned off and the fan (3) operates, providing to increase the amount of hot air delivered by the fan (3) into the cooking chamber (4) and one or more shutters (9) that allow the opening closing of the auxiliary openings (7).