EP1659341A1 - Cooking device with circulating air heater - Google Patents

Abstract

The device has an operating unit (14) provided for controlling heating operation, and a heater designed as a grill heater. The unit (14) activates a circulating air heater (10) for cleaning a circulating air heater surface during the heating operation in an operation mode in a short-term cleaning phase. A ventilator unit (22) generates air flow circulating around the heater (10), and activated by the unit (14) during the operation. An independent claim is also included for a method for operating a cooking device.

Description

The invention relates to a cooking appliance with a circulating air heater according to the preamble of claim 1 and to a method for actuating such a cooking appliance according to the preamble of claim 12.

From DE 27 57 059 A1 a cooking appliance with a circulating air heater and with another, designed as grill radiator radiator is known. The cooking appliance comprises an actuating unit which is suitable for controlling and regulating the further heating body for heating a cooking space in at least one operating mode. The actuation unit activates the further radiator in the operating mode when the circulating air radiator is deactivated.

The object of the invention is in particular to provide a cooking appliance, in which a self-cleaning of the circulating air heater during operation of the cooking appliance in a first mode is feasible, so that deposits on the circulating air heater, in particular in a further mode, does not affect the quality of the Garguts can lead.

The object is achieved by the features of claim 1, while advantageous embodiments and modifications of the invention can be taken from the dependent claims.

The invention relates to a cooking appliance with a circulating air heater, with at least one further radiator and with an actuating unit for controlling and / or regulating a heating operation, wherein the actuating unit is provided, in at least one mode, the further radiator for heating a cooking chamber with deactivated circulating air heater to activate.

It is proposed that the operating unit is provided to activate the circulating air heater for cleaning a circulating air radiator surface during operation in the operating mode in at least one short-term cleaning phase. Thereby deposits on the Umluftheizkörperoberfläche can be burned during operation of the cooking appliance in the mode, and accumulation of deposits can be advantageous be avoided. Such an accumulation would lead to a strong smoke and odor development when activating the circulating air heater, which could lead to the impairment of a quality of a food. Deposits can be caused in particular by grease particles in the vapor.

In this context, "provided" should also be understood to mean "designed" and "equipped". The actuating unit may be designed by hardware or by appropriate software for operating the cooking appliance according to the invention. For cleaning the Umluftheizkörperoberfläche a short-term heating of the circulating air heater to a temperature in the order of 500 ° C is suitable. Activation of the circulating air heater, which is indeed long enough to reach the abovementioned temperature on the circulating air radiator surface, but has no significant effect on a temperature of the cooking product or of the cooking chamber, should be referred to as "short-term". An unavoidable small influence of the cleaning phase on a temperature of the cooking chamber can be taken into account by the actuating unit in a control method.

In one embodiment of the invention, it is proposed that the further radiator is designed as grill radiator. Especially in grill operations, a high concentration of fat particles in the vapor can occur, which can lead to deposits. The implementation of a cleaning phase can then lead to a particularly significant improvement in cooking quality.

Reinforced deposits can also form on the circulating air radiator if the cooking appliance comprises a fan unit for generating a circulating air flow flowing around the circulating air radiator. The circulating air then transports vapor from the cooking chamber in a region of the circulating air heater. The reinforcement of the deposits further increases the efficiency of the cleaning phase in improving the quality of the cooking. This is especially true when the operating unit is intended to activate the fan unit during operation in the operating mode, and especially when the operating unit is intended to activate the fan unit at least in one phase of the operating mode with deactivated circulating air heaters, since deposits can condense out of a hot Wrasenstrom or circulating air flow on the relatively cold, circulating Umluftheizkörperoberfläche. Furthermore, by the fan unit a Overheating of the circulating air heater and / or its environment during the cleaning phase can be advantageously avoided.

An accumulation of deposits during operation of the cooking appliance in the operating mode can be avoided if the operating unit is intended to repeat the cleaning phase periodically. In this case, a flexibly adaptable self-cleaning method can be achieved if the actuating unit is provided to determine a period of the cleaning phase as a function of at least one further parameter. As a further parameter, in particular a temperature of the cooking chamber, a temperature of the food or a degree of browning of the cooking chamber sensed by a tanning sensor come into consideration. Furthermore, the operator can determine such a parameter when selecting an operating mode. There are also embodiments of the invention are conceivable in which a - for example, laser-based - sensor unit detects a degree of contamination of Umluftheizkörpers and the actuator activates the cleaning phase when needed.

An even further adaptivity of the self-cleaning method can be achieved if the actuating unit is provided to determine a duration of the cleaning phase as a function of at least one further parameter.

A satisfactory cleaning without influences on a temperature course in the food, which could negatively affect a cooking quality, can be achieved if a duration of the cleaning phase between 10 s and 1 min.

A targeted use of the cleaning phase in or after phases with increased deposition rate can be achieved when the actuator unit triggers the cleaning phase in connection with a heating phase of the other radiator. By "in context" is meant to express a strong temporal correlation. Depending on a type of operation, the cleaning phase before, after or during the heating phase of the other radiator can be triggered. Furthermore, it would be conceivable that the actuating unit triggers the cleaning phase in connection with a ventilation phase of the fan unit.

Furthermore, the invention relates to an actuating unit for a cooking appliance according to one of the preceding claims. Such an actuating unit must be suitable in particular for the independent activation of the circulating air heater.

In addition, the invention is based on a method for actuating a cooking appliance with a circulating air heater and with at least one further radiator, wherein the further radiator is activated for heating a cooking chamber with deactivated circulating air heater.

It is proposed that during the operation of the cooking appliance in at least one cleaning phase of the circulating air heater is activated for cleaning a Umluftheizkörperoberfläche short term. As a result, an advantageous self-cleaning of the circulating air heater can be achieved.

Further advantages emerge from the following description of the drawing. In the drawings, embodiments of the invention are shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Fig. 1

ein Gargerät mit einem Umluftheizkörper und mit einem weiteren Heizkörper,

Fig. 2

das Gargerät aus Figur 1 in einer Schnittdarstellung,

Fig. 3

eine Darstellung eines zeitlichen Verlaufs einer Betätigung des Umluftheizkörpers, des weiteren Heizkörpers und einer Lüftereinheit des Gargeräts aus den Figuren 1 und 2 in einer Betriebsart und

Fig. 4

eine Darstellung eines zeitlichen Verlaufs einer Betätigung des Umluftheizkörpers, des weiteren Heizkörpers und einer Lüftereinheit des Gargeräts aus den Figuren 1 und 2 in einer alternativen Ausgestaltung der Betriebsart.

Show it:

Fig. 1

a cooking appliance with a circulating air heater and with another radiator,

Fig. 2

the cooking appliance of Figure 1 in a sectional view,

Fig. 3

a representation of a time course of actuation of the circulating air heater, the further radiator and a fan unit of the cooking appliance of Figures 1 and 2 in a mode and

Fig. 4

an illustration of a time course of actuation of the circulating air heater, the further radiator and a fan unit of the cooking appliance of Figures 1 and 2 in an alternative embodiment of the mode.

FIG. 1 shows a cooking appliance designed as a circulating-air baking oven with a convection heater 10 and with a further radiator 12. The further radiator 12 is designed as a grill radiator and arranged in a ceiling region of a cooking chamber 16 of the cooking appliance. The cooking appliance comprises an operating unit 14 designed as a programmable arithmetic unit, which controls and regulates a heating operation of the cooking appliance. The operating unit 14 stores software with a plurality of selectable operating modes. The actuation unit 14 comprises, in particular, signal lines which are not explicitly shown here for transmitting switching signals which cause the circulating air heating element 10 to be switched on and off, a fan unit 22 and / or the further radiator 12. The cooking appliance also includes a control panel 26 with a switching element 28 for selecting an operating mode of the cooking appliance.

If an operator selects an operating mode configured as a recirculating grille mode via the switching element 28, the actuating unit 14 activates the further radiator 12 in cyclically timed heating phases when the circulating air heater 10 is deactivated and activates a fan unit 22 of the cooking appliance alternately with the further radiator 12. Before the beginning of each heating phase, the actuating unit 14 activates the circulating air heater 10 for cleaning a Umluftheizkörperoberfläche 20 of Umluftheizkörpers 10. In this case, the Umluftheizkörper 10 is acted upon by a full supply current, so that the Umluftheizkörperoberfläche 20 heated to about 500 ° C, so that burn deposits that be carried by an air flow generated by the fan unit 22 in the region of the circulating air heater 10 surrounding the fan unit 22 and are deposited on the Umluftheizkörperoberfläche 20. By activating the circulating air heater 10, the actuating unit 14 starts a cleaning phase 18, the duration t is about 30 s and ends with the deactivation of the circulating air heater 10.

The duration t of the cleaning phase 18 determines the actuating unit 14 depending on a further characteristic which is assigned to the operating mode selected by the operator via the switching element 28 and that for different operating modes in a memory unit the operating unit 14 is stored. The same applies to a period T of the cleaning phases 18 or the heating phases.

Figure 2 shows the cooking appliance in a sectional view. The cooking chamber 16 is delimited by a muffle and bounded on a side facing away from a cooking appliance door 30 with viewing window by a ventilation plate 32. The ventilation plate 32 has a central, barred recess and is provided at one edge with louvers 34, 34 '. The ventilation plate 32 separates a partial space from the cooking chamber 16, in which a fan 36 of a fan unit 22 which also comprises an electric motor is arranged. Activates the actuator 14, the fan unit 22, the fan wheel 36 begins to rotate and sucks vapor from the cooking chamber 16 through the barred recess and generates a radially outwardly extending recirculating air flow 24, which formed as Bandheizleiter, the fan 36 circumferentially encompassing circulating air heater 10th flows around, so that 10 deposits on the Umluftheizkörperoberfläche 20 can condense when deactivated Umluftheizkörper. The circulating air stream 24 is finally returned through the air slots 34, 34 'in the cooking chamber 16.

FIG. 3 shows a time sequence of the operating mode or of the cooking program "circulating air grilling". In this case, a continuous line 38 represents the activation of the further radiator 12, a dotted line 40 the activation of the convection heater 10 and a dashed line 42 the activation of the fan unit 22. The value 1 corresponds to activation of the respective unit while the unit is deactivated, if the corresponding line has the value 0. After a preheating phase, not shown here activates the actuator 14 during a 5-minute ventilation phase, the fan unit 22 and the circulating air flow 24. During a 5 min lasting, carried out in alternation with the ventilation phase heating phase, the actuator unit 14 activates the other radiator 12. At the end of each Ventilation phase, immediately before the start of the heating phase activates the actuator 14, the circulating air heater 10 and starts a cleaning phase 18 with a duration t of 30 s, which ends with the beginning of the heating phase. According to the period of the heating phases, a period T of the cleaning phases 18 is 10 minutes.

FIG. 4 shows an alternative embodiment of the operating mode "circulating air grilling", which is achieved by a suitable modification of a control program implemented in the actuating unit 14 can be carried out with the cooking appliance shown in Figure 1. In this case, heating phases of the further radiator 12 are triggered by a control circuit implemented in the actuating unit 14 and always start when a temperature of the cooking chamber 16 detected via a temperature sensor (not shown here) of the cooking appliance falls below a minimum value. As a result, the heating phases occur at irregular intervals, while the cleaning phases 18 are triggered by the operating unit 14 having the period T, the value of which is stored in the storage unit of the operating unit 14.

reference numeral

10

Recirculating air heating

12

radiator

14

operating unit

16

oven

18

cleaning phase

20

Convection radiator surface

22

fan unit

24

circulating air flow

26

Control panel

28

switching element

30

cooking appliance

32

ventilation Panels

34

Louvre

36

fan

38

line

40

line

42

line

t

duration

T

period

Claims (12)

Cooking appliance having a circulating air heating element (10), with at least one further heating element (12) and with an actuating unit (14) for controlling and / or regulating a heating operation, wherein the actuating unit (14) is provided in at least one operating mode the further heating element (12). 12) for heating a cooking chamber (16) when the circulating air heater (10) is deactivated, characterized in that the operating unit (14) is provided, during operation in the operating mode in at least one short-term cleaning phase (18) the circulating air heater (10) to activate a Umluftheizkörperoberfläche (20). Cooking appliance according to claim 1, characterized in that the further heating element (12) is designed as grill radiator. Cooking appliance according to one of the preceding claims, characterized by a fan unit (22) for generating a recirculating air flow (24) flowing around the circulating air heating element (10). Cooking appliance according to claim 3, characterized in that the actuating unit (14) is provided to activate the fan unit (22) during operation in the operating mode. Cooking appliance according to claim 4, characterized in that the actuating unit (14) is provided for activating the fan unit (22) at least in one phase of the operating mode when the circulating air heating element (10) is deactivated. Cooking appliance according to one of the preceding claims, characterized in that the actuating unit (14) is provided to repeat the cleaning phase (18) periodically. Cooking appliance according to one of the preceding claims, characterized in that the actuating unit (14) is provided to determine a period (T) of the cleaning phase (18) depending on at least one further parameter. Cooking appliance according to one of the preceding claims, characterized in that the actuating unit (14) is provided to determine a duration (t) of the cleaning phase (18) depending on at least one further parameter. Cooking appliance according to one of the preceding claims, characterized in that a duration (t) of the cleaning phase (18) is between 10 s and 1 min. Cooking appliance according to one of the preceding claims, characterized in that the actuating unit (14) is provided to trigger the cleaning phase (18) in connection with a heating phase of the further heating body (12). Actuating unit (14) for a cooking appliance according to one of the preceding claims. Method for actuating a cooking appliance with a circulating air heating element (10) and with at least one further heating element (12), wherein the further heating element (12) is activated for heating a cooking chamber (16) when the circulating air heating element (10) is deactivated, characterized in that at least a short-term cleaning phase (18) of the circulating air heater (10) for cleaning a Umluftheizkörperoberfläche (20) is activated.

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