EP0762059A2 - Electric safety device for kitchen ranges or cooking plates and a method for operating a kitchen range or a cooking plate - Google Patents

Abstract

The safety device has sensors (13,15,17,18-21,22) positioned above the oven or hob for detecting smoke and monitoring the temp. The sensor signals are fed to an evaluation stage (24) for operation of an electric cut-out switch or an electromagnetic blocking valve for the oven or hob. The evaluation stage has a resetting input (11) for manual resetting upon disconnection of the energy supply to the oven or hob, with automatic resetting after a defined time interval.

Description

Technical field:

The invention relates to an electrical safety device for kitchen stoves or fireplaces that are operated energetically with electrical energy or combustible gases, according to the preamble of claim 1, and to a method for operating a kitchen stove or a hotplate according to the preamble of claim 10.

State of the art:

Protective devices for kitchen stoves and hotplates are known in the form of thermostats or ignition fuses, which are attached to the stove or in the immediate vicinity of the burning or heating point, in order to interrupt the gas supply when the gas flame is absent or extinguished. Furthermore, stoves have become known which are operated energetically with electrical energy, the energy being passed on inductively to metal pots which heat up as a result of the eddy current losses generated. This means an additional security, because without placing a metal pot on the heating element giving off energy, heat cannot be given off. Furthermore, automatic fire extinguishing systems similar to sprinkler systems have been developed for commercial kitchens, which can in principle also be used for private cooking areas. Such systems trigger an extinguishing process.

DE 30 39 246 A1 discloses an extractor hood with a controllable blower motor for use in kitchens, which has a sensor element that responds to moisture and / or haze and / or smoke and / or heat and faces the stove surface. Furthermore, two sensor elements can be present, one on the side of the cooker hood facing the stove and the other on the side of the cooker shielded from the stove surface. From DE 37 37 712 C2 an electric cooker is known which automatically switches off one or more heat sources after switching on a heat source via an operating switch and after a predetermined time without any further switching, and likewise after the predetermined time since the last switching of a heat source the electric stove is switched off automatically. Likewise, DE 35 35 743 A1 a shutdown safety device for electric cookers is known, which ensures a complete shutdown of the electric cooker in the event of overheating.

From US-PS 46 59 909 a safety shutdown for a stove with electric hotplates has become known, the power supply includes a resettable switch-off device to switch off the power supply when the current rises above a predetermined value. The shutdown device comprises a smoke detector which is mounted outside the cooker and is capable of emitting an electrical signal in the event of smoke. A device for interrupting the power supply is connected to the above-mentioned signal transmitter in order to automatically interrupt the power supply to the cooker. Furthermore, a device for detecting a predetermined boiling state of a liquid is known from the US-PS 50 79 407, which is located on a hob of a kitchen range. A moisture sensor delivers a first signal at a predetermined humidity, which actuates a timer circuit which supplies a second signal which is capable of triggering an audible or visible alarm, and also to control or control the heating source with which the liquid is heated. switch off. For this purpose, a stable multivibrator is used within the timer circuit, on which the signal from the moisture sensor is applied.

Technical task:

The invention has for its object to reduce the given operational risk of cookers and hobs, which are operated energetically with electrical energy or flammable gases, and the associated risk of a house fire and thus the environmental impact of pollutants, which are economically justifiable in such fires to reduce; Furthermore, any existing stove or hotplate should be able to be retrofitted.

Disclosure of the invention and its advantages:

The object is achieved, according to the invention, by various sensors arranged above the kitchen stove and / or the hotplate, which are smoke sensors and / or temperature sensors and / or moisture sensors and / or grease vapor sensors and / or flame sensors, the signals of which are processed by evaluation electronics equipped with a timer whose an exit with a Separating element, preferably an electrical switch or electromagnetic valve, is connected for the energy supply for the kitchen stove or the hotplate, in such a way that the evaluation electronics limit values for smoke and / or temperature and / or water vapor and / or grease vapor and / or flames can be specified, which are at If the time supply exceeds a predefined time, switch off the energy supply to the kitchen range or the cooking zone with a time delay, the evaluation electronics having a reset input that can be operated by the operator, with which the output signal of the evaluation electronics for switching off the energy supply to the kitchen range or the cooking range can be reset within the preset switch-off time. If a limit value for smoke and / or flames or temperature and / or water and / or fat vapor is exceeded, the evaluation electronics can emit a time-delayed switch-off signal that can be reset within the delay time for the energy supply to the kitchen range or the cooking zone.

The invention has the advantage that the electrical safety device according to the invention can be drastically reduced with an economically justifiable effort, the given operational risk of kitchen stoves or hotplates and the risk of a house fire. This also drastically reduces the environmental impact of pollutants that arise from such fires. Another economic advantage lies in the fact that the invention gives older and / or disabled people the opportunity to live longer and, above all, more safely and independently in their apartments without moving to a retirement home. Virtually all existing cookers or hotplates that are operated energetically with electrical energy or flammable gases can be easily retrofitted by a gas and / or electrician, which ensures a high level of attractiveness for the dissemination of the invention.

In an advantageous further embodiment of the invention, this has a time-controlled safety main switch for starting the kitchen range or the hotplate, which, after a predeterminable time, but at least after a predetermined time has elapsed, in principle the energy supply to the kitchen stove or the hotplate, even without reaching a limit value how smoke and / or temperature and / or the water and / or grease vapor and / or flames, is able to switch off due to the passage of time.

Furthermore, the safety device can have an extinguishing system which can be activated when detecting flames and / or a specific, predetermined concentration of smoke development and / or when a predetermined temperature is exceeded. The evaluation electronics can emit acoustic and / or optical warning signals before the kitchen stove is switched off.

In cooking or roasting processes in which smoke development is unavoidable, the evaluation electronics of the safety device can trigger an increasing or swelling acoustic and / or optical signal for signaling to the operator so that he actuates the reset, in order thereby to activate the pre-armed switch-off signal within the possible range Deactivate switch-off time.

The safety device can preferably be integrated in an extractor hood above the kitchen range or the hotplate.

Depending on the number of hotplates, such a sensor or a plurality of sensors, in particular a temperature sensor, can be arranged above each, an oven possibly also having a temperature sensor. Furthermore, the safety device can have a central temperature sensor connected to the evaluation electronics for integrally detecting the temperature, which is able to act on its response to the main safety switch.

A method for monitoring kitchen stoves and / or hotplates which are operated energetically with electrical energy or combustible gases, using an electrical safety device arranged above the kitchen stove and / or the hotplate with evaluation electronics which have at least one acoustic and / or optical signal detector , is characterized in that temperature, smoke development, water and / or grease vapor and / or flames are monitored by means of electrical sensors which are preset to a predetermined limit value and whose output signals are recorded in an electronic evaluation unit, with a or respond to several of the limit values within a predetermined limit value period of the acoustic signal and / or optical signaling device, but within this time period no cut-off of the power supply to the kitchen range or the cooking zone is triggered and the operator in response to the response of the acoustic and / or optical signal Signal detectors, preferably within a further, predefinable reset time period, must manually trigger a reset signal in order to ensure a further energy supply to the kitchen range and / or the cooking zone and the energy supply to the kitchen range and / or the cooking zone is only switched off if either one or more of the limit values of the sensors exceed the limit time period or the operator does not trigger the reset signal within the reset time period, the reset time period being chosen to be smaller or larger than the limit value period and the reset time period either exceeds the limit value time period or can be within the same.

Brief description of the drawing, in which:

Figure 1

a basic arrangement of an extractor hood, in which a safety device is integrated, with a kitchen stove and a separating element in the energy supply for the kitchen stove

Figure 2

a schematic arrangement of the elements of the safety device and

Figure 3

a section through an extractor hood with integrated safety device for the kitchen stove.

Preferred embodiment of the invention:

According to FIG. 1, an electrical safety device for a kitchen stove 1 is preferably and for the most part integrated into an extractor hood 2, a separating element 3 being arranged within an energy supply line 4 for the kitchen stove 1, which can be a gas pipe or an electrical pipe is either an electromagnetically actuated valve or an electrical isolating switch. An energy line 6 leads from the separating element 3 to the kitchen stove 1, and a control line 5 leads into the separating element 3, with which the separating element 3 with the extractor hood 2 and the units arranged there electrically connected is. The extractor hood 2 is supplied with electrical energy via an electrical power supply 7.

Figure 2 shows a schematic representation of the elements of the safety device, which can be integrated within the extractor hood 2 of Figure 1. Arranged within a control panel 8 are at least one optical and one acoustic detector 9, 10 as well as a reset button 11 for resetting the output signal of the evaluation electronics and possibly a button 37, which can be identical to the reset button 11, but which can also be assigned other control functions. Likewise, a foot switch or the like can be present instead of the button.

An exhaust air monitoring field 12 comprises at least one thermal sensor 13, 19 for the exhaust air, a fan 14 and a smoke sensor 15. Likewise, separate from the smoke sensor 15, at least one sensor 35 can be arranged which specifically responds to water and / or grease vapor.

A hob monitoring device 16 has a majority of thermal sensors 17, 18, 19, 20, 21, with such a thermal sensor preferably being assigned to each hob. The centrally arranged thermal sensor 19 can preferably serve for the integral detection of the temperature and thus also of the exhaust air. Furthermore, an oven monitor 22 can also be equipped with a temperature sensor 23. A specific flame sensor 38 can also be present, which can also be integrated in the exhaust air monitoring field 12 and which is preferably an IR sensor.

From a central evaluation electronics 24, which can also be arranged in the extractor hood 2, electrical leads 25, 26, 27, 28 lead to the elements mentioned, as well as the electrical evaluation electronics 24 are connected to the electrical control line 5 to the separating element 3, as well the electrical power supply 7 of the electrical safety device or the extractor hood 2 is routed via the evaluation electronics 24.

The function of the device is as follows:

The electrical sensors 13, 15, 35 of the exhaust air monitoring field 12 and the sensors 17, 18, 19, 20, 21 of the hob monitoring 16 monitor the temperatures of the exhaust air as well as of the individual hotplates and of any arising Smoke and, if necessary, water vapor and fat vapor. In the evaluation electronics 24, limit values are specified for the individual sensors, when exceeded, the evaluation electronics emits an output pulse to the separating element 3, which disconnects the energy supply via the line 6 to the kitchen range 1. Or the evaluation electronics 24 actuates a main safety switch 34, which in turn actuates the separating element 3 and interrupts the energy supply to the kitchen stove 1.

The evaluation electronics 24 also has a timer or a timer, by means of which the cooking time can also be monitored. For example, the timer or the time switch switches the kitchen stove off under all circumstances after a predetermined period of time, although this period of time cannot exceed a predetermined limit value, for example one hour. The kitchen stove 1 can be restarted immediately by operating the main safety switch 34.

Furthermore, the timer has the task of also triggering the separating element 3 within one or more presettable short limit time periods when one or more preset limit values of the sensors, such as with regard to the temperature or when detecting smoke or water or fat vapor or flames, is triggered and switch off the kitchen stove from the power supply. These short or short limit value periods after one of the limit values mentioned can be, for example, 10 to 30 seconds.

Temperature, smoke development, possibly water and fat vapor as well as flames and time are thus detected by the evaluation electronics 24. Short-term violations of the limit values, for example a steam cloud when a lid is lifted, are signaled acoustically or optically within the limit period specified for this purpose, but do not yet trigger a shutdown of the energy supply to the kitchen range 1. Now the operator must trigger a reset signal within a further short reset period, for example 10 to 25 seconds, by means of the reset button 11 in order to avoid switching off the energy supply to the kitchen range. If, on the other hand, there is no reset of the signal within the abovementioned short reset period after an error message or a message that the limit value has been briefly exceeded, the kitchen stove is switched off according to the Todtmann principle. The reset time period can be smaller or larger than the limit value time period, just as the reset time period either exceeds the limit value time period or can be within the same time. The two time periods can be specified independently of one another, and it is usually not possible to intervene in an increasing limit value.

In cooking or roasting processes in which smoke cannot be avoided, the smoke sensors can trigger a swelling acoustic and / or signal, which is intended to induce the operator to press the reset button 11 or, for example, several times at shorter intervals Notify button 37 that everything is OK. If this message or multiple messages does not occur within a specified period of time, for example again within 10 to 25 seconds, the kitchen range is switched off again from the energy supply.

FIG. 3 shows a further embodiment of a device which is integrated in an extractor hood 2, in which a grease filter 29 and an extinguishing system 36 are arranged in addition to the elements mentioned; specific flame detectors may also be present. A large-area button 37 is arranged within the control panel 8. The electrical safety device can be supplemented by an automatic fire extinguishing system 36 with the effect that in the event of a fire occurring despite the existing safety measures, e.g. due to the fact that flammable objects are in the flame area of a gas stove, the damage remains as small as possible. If a fire should nevertheless occur, the extinguishing system 36 is activated automatically and extinguishes the fire with an extinguishing agent suitable according to the prior art.

Furthermore, a central temperature sensor 19 is advantageously provided for integral monitoring of the temperature, which switches the kitchen stove off under all circumstances, for example when a given limit value is reached, the signal from this temperature sensor 19 not being able to be reset by means of the reset button 11.

Industrial applicability:

The object of the invention is particularly applicable in households and provides an electrical safety device that a Switching off a kitchen stove or hotplates due to unusual heat development with reset option and independently switching off due to smoke development with reset option, both options can be integrated with an extinguishing system. In addition, the safety device can have separate sensors for water vapor and / or grease vapor and or flames.

List of reference numerals:

1

Kitchen stove

2nd

Extractor hood

3rd

Separating element

4th

Energy supply (electricity or gas)

5

electrical control line to the extractor hood

6

Energy supply (electricity or gas) from the separating element to the kitchen stove

7

electrical power supply to the extractor hood

8th

Control panel

9, 10

optical and acoustic detector

11

Reset button

12th

Exhaust air monitoring field

13,17,18,19,20,21,23

Thermocouple

14

Fan

15

smoke detector

16

Hob monitoring

22

Oven monitoring

24th

Evaluation electronics

25, 26, 27, 28

electrical leads

29

Haze filter

30, 31, 32

Tube

33

Hob lighting

34

Safety main switch

35

Water and grease vapor sensor

36

Extinguishing system

37

Button

38

Flame sensor

Claims (11)

Electrical safety device for kitchen stoves and / or hotplates which are operated energetically with electrical energy or flammable gases,
characterized by various sensors (13, 15, 17, 18, 19, 20, 21, 23) arranged above the kitchen stove (1) and / or the hotplate, which smoke sensors (15) and / or temperature sensors and / or moisture sensors and / or Fat vapor sensors and / or flame sensors, the signals of which are processed by evaluation electronics (24) equipped with a timer, the output of which has a separating element (3), preferably an electrical switch or electromagnetic valve, for the energy supply for the kitchen range (1) or Cooking station is connected in such a way that the evaluation electronics (24) are given limit values for smoke and / or temperature and / or water vapor and / or grease vapor and / or flames which, when exceeded for a predeterminable time of the timer, the energy supply of the kitchen range (1) or switch off the hotplate with a time delay, the evaluation electronics (24) having a reset input (11) which can be operated by the operator with which the output signal of the evaluation electronics (24) for switching off the energy supply of the kitchen range (1) or the hotplate can be reset within the preset switch-off time. Safety device according to claim 1,
characterized in that, when a limit value for smoke and / or flames or temperature and / or grease vapor and / or water vapor is exceeded, the evaluation electronics (24) emit a time-delayed switch-off signal which can be reset within the delay time for the energy supply of the kitchen range (1) or the hotplate is able. Safety device according to claim 1 or 2,
characterized in that there is a time-controlled safety main switch (34) for starting up the cooker (1) or the hotplate, which, after a predeterminable time, but at least after reaching a predetermined time, principally supplies the energy to the cooker (1) or Cooking area even without reaching a limit, such as with regard to smoke development and / or temperature and / or Water vapor and / or grease vapor and or flames, is able to switch off due to the passage of time. Safety device according to claim 1 or 2,
characterized by an extinguishing system (36) which can be activated when detecting flames and / or a certain, predetermined concentration of smoke development and / or when a predetermined temperature is exceeded. Safety device according to claim 1 or 2,
characterized in that during cooking or roasting processes in which smoke development is unavoidable, the evaluation electronics (24) is able to trigger an increasing or swelling acoustic or optical signal for signaling to the operator to reset the switch-off signal. Safety device according to claim 1,
characterized in that the evaluation electronics (24) are able to emit acoustic and / or optical warning signals before the kitchen stove (1) or the hotplate is switched off. Safety device according to claim 1,
characterized in that the same is integrated in an extractor hood (2). Safety device according to claim 1 or 7,
characterized in that such a sensor or sensors, in particular a temperature sensor (17, 18, 19, 20, 21), is arranged over each according to the number of hotplates and, if appropriate, an oven likewise has a temperature sensor (23). Safety device according to claim 1,
characterized in that it has a central temperature sensor (19) connected to the evaluation electronics (24) for the integral detection of the temperature, which is able to act on the main safety switch (34). Method for monitoring kitchen stoves (1) and / or hotplates that are operated energetically with electrical energy or combustible gases, using an electrical safety device arranged above the kitchen stove (1) and / or the hotplate with evaluation electronics (24), which at least has an acoustic and / or optical signal detector,
characterized,
that temperature, smoke development, water and / or grease vapor and / or flames are monitored by means of electrical sensors (13, 15, 17, 18, 19, 20, 21, 23), which are preset to a predetermined limit value and their output signals in an electronic evaluation system (24) can be detected, whereby if one or more of the limit values is briefly exceeded within a predetermined limit value period, the acoustic signal and / or optical signaling device (s) respond, but within this time period there is still no switch-off of the power supply to the kitchen range (1) or the hotplate is triggered and the operator in response to the response of the acoustic and / or optical signal detectors must manually trigger a reset signal to ensure a further power supply to the kitchen range (1) and / or the hotplate and to switch off the power supply to the kitchen range and / or the hotplate only occurs if either one or more de r Limit values of the sensors exceed the limit value period or the operator does not trigger the reset signal within the reset period, the reset period being able to be selected to be shorter or larger than the limit period and the reset period either exceeding the limit period or can be within the time limit. A method according to claim 10, characterized in
that the reset signal must be triggered within a predeterminable reset time period.

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