Patent Application
20180340693
This application claims the benefit of foreign priority to DE 10 2017 111 249.9 and DE 10 2017 111 246.4, both filed on 23 May 2017, each of which is herein incorporated by reference in its entirety for all purposes.
The following description relates to a method for identifying the degree of soiling of an interior of a cooking appliance, in particular of the cooking chamber, during a cleaning operation and/or a cooking operation and relates to a method for cleaning a cooking appliance interior as a function of a degree of soiling.
Cooking foods results in soiling in the cooking chamber of the cooking appliance used, for example on the walls, ceiling or floor. Different types of soiling arise here, for example caused by proteins, carbohydrates, carbonates, sugars and/or fats, with different degrees of soiling, specifically depending on the foodstuffs to be cooked and the duration of use between cleaning phases. Due to the different soiling, cleaning of the cooking appliance requires a cleaning method which is specifically adapted to the soiling. Modern cooking appliances permit the selection of various cleaning methods, but during the actual cleaning do not permit any change to the cleaning parameters, such as for example temperature and quantity of cleaning agent, in particular in response to the current degree of soiling during the cleaning phase. This is, however, desirable in order to extend the service life of the appliance, save costs and avoid any needless environmental impact, in that smaller quantities of cleaning agents and less energy are required during the actual cleaning operation.
DE 10 2007 005 501 A1, for example, describes a method for cleaning a food processing appliance, in which the degree of soiling over a period between two cleaning cycles is evaluated and the cleaning program adapted accordingly. Adaptation of the cleaning method during cleaning is not provided.
DE 10 2007 005 503 describes a method for cleaning at least one surface within at least one interior and/or container of a food processing appliance by introducing at least one cleaning fluid into the interior and/or container as well as an abrasively acting granular material which, depending on the temperature, is at least partially dissolved in the cleaning fluid.
DE 20 2006 003 365 U1 describes a cooking appliance which inter alia has sensors which measure the physical parameters of a liquid.
WO 03/073002 A1 describes a method for cleaning an interior of a cooking appliance, in which the interior is cleaned with a cleaning fluid during at least one cleaning cycle and rinsed with water at the end of the cleaning cycle. A tab is here introduced into the interior for example via a hatch. The hatch can be opened or closed as a function of a time controller and/or the degree of soiling, in particular determined via at least one turbidity sensor, without any details in this connection being described.
In an aspect, a method for identifying the degree of soiling during cleaning and/or cooking of a cooking appliance interior which verifies the particular current degree of soiling in order to be able in particular to adapt a currently running cleaning method or determine future cleaning methods is described. In addition, a method is provided for cleaning a cooking appliance interior which permits adaptation of a cleaning operation to the particular degree of soiling during the cleaning operation, in particular by determining the degree of soiling of a washing liquor located in the cooking appliance interior at any desired point in time of the cleaning operation. The invention thus provides a flexible, inexpensive and environmentally responsible method which ensures clean interiors in cooking appliances in the most efficient manner.
In an aspect, a method for identifying the degree of soiling of an interior of a cooking appliance, in particular of the cooking chamber, during a cleaning operation and/or a cooking operation includes determining at least one parameter of a liquid over time and determining the degree of soiling of the interior from the change in the at least one parameter and wherein the at least one parameter is a physical variable which is determined via at least one sensor.
It may be provided that at least one first parameter of the liquid is determined at a first point in time of the cleaning or cooking operation and at least one second parameter of the liquid is determined at a second point in time of the cleaning or cooking operation; and the degree of soiling is determined from the change in and/or difference between the first and second parameters and comparing the change in and/or difference between the first and second parameters with at least one predetermined or predeterminable limit value.
Preferably, in order to determine the degree of soiling at a plurality of points in time, the at least one parameter is detected, and/or the progression of the at least one parameter over time is detected, and/or at least one maximum and/or at least one minimum of the progression of the at least one parameter over time is detected, and/or the gradient and/or curvature of the progression of the at least one parameter over time is detected and/or a regression analysis of the parameters is carried out.
It is furthermore proposed that the time interval between two successive measurements is lengthened or shortened, in particular via the open- or closed-loop control device, as a function of the detected parameters, the detected progression of the parameters, the detected maximum of the progression of the parameters, the detected minimum of the progression of the parameters, the detected gradient and/or curvature of the progression of the parameters and/or the regression analysis.
It may also be provided that the degree of soiling and/or at least one, in particular previously carried out program, selected from a plurality of cleaning programs and/or cooking programs, is determined, in particular via the open- or closed-loop control device, as a function of the detected parameters, the detected progression of the parameters, the detected maximum of the progression of the parameters, the detected minimum of the progression of the parameters, the detected gradient and/or curvature of the progression of the parameters and/or the regression analysis.
The identified or determined degree of soiling may be displayed at least temporarily, preferably automatically or on request.
A further embodiment provides a method for cleaning a cooking appliance interior which comprises the following steps after the start of a cleaning operation having at least one cleaning phase: a) introducing a washing liquor into the cooking appliance interior and starting the at least one cleaning phase using one or more cleaning parameters; b) determining at least one first parameter TS1 of the washing liquor at a first point in time t1 of the cleaning operation and determining at least one second parameter TS2 of the washing liquor at a second point in time t2 of the cleaning operation; and c) determining the degree of cleaning of the cooking appliance interior from the change in the parameters; wherein, depending on the change in the parameters, steps a) to c) are repeated and/or at least one of the cleaning parameters is adapted or the at least one cleaning phase is terminated.
In order to determine the degree of cleaning at a plurality of points in time, the at least one parameter may be detected, and/or the progression of the at least one parameter over time may be detected, and/or at least one maximum and/or at least one minimum of the progression of the at least one parameter over time may be detected, and/or the gradient and/or curvature of the progression of the at least one parameter over time may be detected and/or a regression analysis of the parameters may be carried out.
It may furthermore be provided that the degree of cleaning of the cooking appliance interior is determined from the change in and/or difference between the first parameter relative to the second parameter, ΔTS1=TS2−TS1, and by comparing the change in and/or difference between the parameters with at least one known limit value TSlimit.
Initial cleaning parameters may be determined by determining at least one parameter TS0 at a point in time t0 and/or by manual selection of a cleaning program.
It is proposed that at least one of the parameters of the cleaning operation is paused prior to determination.
It may additionally be provided that the first point in time t1 is selected during the at least one cleaning phase and the second point in time t2 after the at least one cleaning phase, wherein the cleaning operation is preferably terminated when the at least one limit value is reached.
Furthermore, as a function of the identified or determined degree of cleaning, at least one cleaning parameter, at least one limit value and/or at least one time interval between the determination of two parameters may be determined, stored and/or displayed for at least one subsequent cleaning phase of the cleaning operation and/or a future cleaning operation.
Likewise, as a function of the identified or determined degree of cleaning, at least one cleaning parameter of at least one previous cleaning phase of the cleaning operation may be determined, stored and/or displayed.
Also, as a function of the identified or determined degree of cleaning, at least one characteristic variable of at least one previous cooking operation may be determined, stored and/or displayed and/or, as a function of the identified or determined degree of cleaning, a user behavior may be determined, stored and/or displayed.
The at least one determined or adapted cleaning parameter may be selected from the duration of the at least one cleaning phase, the temperature during the at least one cleaning phase, the speed of circulation of the cleaning agent, the acceleration of circulation of the cleaning agent, the chemistry of the cleaning agent, the quantity of cleaning agent and/or the quantity of washing medium, in particular water.
The at least one cleaning phase may be selected from a cleaning product phase, a rinse aid phase and/or a descaler phase, and/or the chemistry of the cleaning agent can be selected from a cleaning product, a rinse aid and/or a descaler.
The minimum of the time progression of parameters for turbidity may here be detected or determined and, on the basis of the parameter at the minimum, the degree of soiling may be determined, wherein the parameter at the minimum is smaller at a greater degree of soiling.
It may additionally be provided that, as a function of the identified or determined degree of soiling, an ongoing cleaning operation is adapted and/or a suggestion for and/or a modification to a future cleaning program is determined and/or at least one characteristic variable of a previous and/or the current cooking operation is determined and/or a user behavior is determined.
The liquid selected may be a washing liquor during a cleaning operation or a water reserve upstream from an outlet of the cooking appliance during a cooking operation.
It may here be provided that the cleaning operation is paused during a cleaning operation prior to determination of at least one of the parameters. It may in turn here be provided that the duration of the pause in the cleaning operation and/or the timing of the pause in the cleaning operation is determined, in particular via the open- or closed-loop control device, as a function of the detected parameters, the detected progression of the parameters, the detected maximum of the progression of the parameters, the detected minimum of the progression of the parameters, the detected gradient and/or curvature of the progression of the parameters.
At least one parameter of a liquid, namely preferably a washing liquor located in the cooking appliance interior or a water reserve located downstream of the cooking chamber, may be determined over time in order to allow the degree of soiling of the cooking appliance interior to be determined from the change in the at least one parameter, wherein the at least one parameter is a physical variable which is determined via at least one sensor. The physical variable is preferably the turbidity.
The at least one sensor may be installed in the cleaning path of the washing liquor or liquid, the pump sump, the cooking chamber, the cleaning product box and/or downstream (in a pipe) of the cooking chamber and/or an open- or closed-loop control device carries out the measurement and/or the evaluation of the measured values obtained, wherein the open- or closed-loop control device preferably includes the at least one sensor.
The at least one parameter may be a physical variable which is selected from the turbidity, pH, conductivity, viscosity, color, refractive index, fluorescence, adsorption, emission and/or density of the washing liquor, and/or for the at least one sensor to be selected from an optical sensor, a turbidity sensor, a pH sensor, a conductivity sensor, a viscosity sensor, a color sensor, a sensor for measuring refractive index, a fluorescence sensor, a sensor for measuring adsorption and/or emission and/or a density sensor.
A washing liquor means a mixture of one or more washing media and one or more cleaning agents which are introduced in particular into the cooking chamber of the cooking appliance via corresponding feed line(s) or devices provided for this purpose. A suitable washing medium is water. The one or more cleaning agents are for example cleaning products, rinse aids and/or descalers. Cleaning agents may be solid or liquid, wherein they are in particular used in the form of tabs, for example as single-phase tabs (which comprise just one cleaning agent or one auxiliary) or multi-phase tabs (which comprise various cleaning agents and auxiliaries, usually in a plurality of layers/zones). The one or more cleaning agents may be added by manual or automatic dispensing, for example by the initially used cleaning program, via corresponding dispensers. The one or more cleaning agents may also be dispensed, preferably automatically, only once the first parameter has been determined at the beginning of the cleaning method. For example, the one or more cleaning agents may be dispensed, preferably automatically, only once a first parameter T0 and a resultant degree of soiling have been determined at a point in time t0 at the beginning of the cleaning method. The cleaning agents may simultaneously be present in the washing liquor in any combination or are used in succession in different cleaning phases. For example, the method may first of all be carried out with a washing liquor consisting of washing medium and cleaning fluid, cleaning powder or cleaning tabs. Thereafter, a rinsing phase may then for example be carried out.
A water reserve may include a liquid substantially consisting of water in a condenser and/or a cleaning tank connected thereto, which may also be denoted pump sump, since the condenser and/or the cleaning tank is normally connectable with the interposition of at least one pump to an outlet of the cooking appliance and/or to a return line to the cooking chamber.
The cleaning parameters are for example provided by selecting a specific cleaning program. The cleaning program may be suggested by the cooking appliance or may be selected manually. In one embodiment, the cleaning parameters may also be automatically selected and applied depending on the degree of soiling of the cooking appliance interior only once the first parameter of the liquid has been determined. In another embodiment, the cleaning parameters may also be automatically selected and applied depending on the degree of soiling of the cooking appliance interior only once a first parameter TS0 of the washing liquor has been determined at a point in time t0 at the beginning of the cleaning method. It is also possible to change cleaning parameters manually. Cleaning parameters are for example temperature, duration of a cleaning phase, chemistry of the cleaning agent used or quantity of cleaning agent used, without being limited thereto. A cleaning program may additionally comprise a plurality of different cleaning phases which are in each case determined by cleaning parameters.
The at least one parameter of the washing liquor may be determined over time during a cleaning operation after the start thereof and introduction of the washing liquor into the cooking appliance interior, in particular into the cooking chamber of the cooking appliance. The change in the parameter provides information about the current degree of soiling of the washing liquor.
In the case of measurement of soiling during a cooking operation, the water reserve is soiled during said operation for example with juice released from a foodstuff being cooked, such that the soiling of the cooking chamber is determinable via the detection of the at least one parameter of the water reserve over time. The change in the parameter here again provides information about the current degree of soiling.
In one embodiment, the difference in the parameters obtained results in a measured variable, on the basis of which a conclusion may be drawn about the degree of soiling for example of the washing liquor during a cleaning operation and thus the degree of cleaning of the cooking appliance interior. At least one first parameter of the washing liquor may here be determined at a first point in time t1 of the cleaning operation and at least one second parameter of the washing liquor at a second point in time t2 of the cleaning operation, such that the degree of soiling may be determined from the change in and/or difference between the parameters at points in time t1 and t2 and comparing the change in and/or difference between the parameters with a known limit value. In a further embodiment, a plurality of parameters provides insight into the degree of soiling.
The respective parameters may be determined by at least one sensor. Such a sensor may be arranged at any suitable position in the cooking chamber, i.e. the cooking appliance interior or downstream of the cooking appliance interior, such that the parameter may be optimally determined with the result that the parameter is ascertained as accurately as possible. The at least one sensor may preferably be installed in the cleaning path of the washing liquor, in a control box, the pump sump, the cooking chamber, a cleaning tank, a condenser and/or a pipe of the cooking appliance. The method may use more than one sensor, for example two, three or four or more sensors. Identical sensors may here be arranged at different positions of the cooking appliance. In a further embodiment, a plurality of different sensors may be arranged in the cooking appliance so that different parameters may be ascertained, which may result in a further improvement in measuring accuracy and thus in determination of the degree of soiling.
The at least one sensor may be a sensor for measuring the turbidity, pH, electrical conductivity, viscosity, color, refractive index, fluorescence, adsorption, emission and/or density of the washing liquor. Further types of sensors which may be used to determine the degree of soiling or degree of cleanliness are possible but a turbidity sensor is preferred. The above-stated sensors are known to a person skilled in the art and may, as described above, be used individually or also in combination. The respective parameter of the liquid determined by the sensor(s) provides information about the degree of soiling of the cooking appliance.
The at least one parameter is a physical variable selected from the turbidity, pH, electrical conductivity, viscosity, color, refractive index, fluorescence, adsorption, emission and/or density of the washing liquor. Further physical variables which are suitable for determining the degree of soiling are possible.
An open- or closed-loop control device may carry out or initializes the respective measurements, for example at points in time t1 and t2. The first measurement is for example carried out during a cleaning operation at a predetermined point in time, for example at a predetermined point in time t1, advantageously shortly after the start of a first cleaning phase in order to obtain a first parameter, for example a first parameter TS1 . In one embodiment, the first measurement is carried out directly after introduction of the washing liquor into the cooking appliance interior. The time interval or time gap between the individual measurements, for example between points in time t1 and t2, is preset, but can also be manually modified in order to ensure the degree of soiling is determined as accurately as possible. The time interval between two measurements is, for example, 45 seconds, 60 seconds, 90 seconds, 2 minutes, 5 minutes or any other suitable time interval. This time interval is generally sufficient to draw a conclusion about the degree of soiling from the values obtained, for example a first parameter TS1 and a second parameter TS2. On the basis of the parameters obtained, the open- or closed-loop control device can, as required, lengthen or shorten the time interval between the measurements. One embodiment provides acquiring a plurality of measured values simultaneously or within a very short interval and calculating an averaged parameter from the ascertained measured values. In this manner, it is possible to achieve an increase in measuring accuracy and to take account of the fact that cleaning does not proceed entirely linearly. In one embodiment, a parameter TS0 is determined at a point in time t0 right at the beginning of the cleaning operation and, as a consequence of this value, the first, i.e. the initial, cleaning parameters are determined.
On the basis of the parameters obtained, for example at points in time t1 and t2, it is possible to draw a conclusion about the current degree of soiling of the cooking chamber, about the progression in the state of soiling, about the current state of cleaning or about the progression in the state of cleaning. For example, the difference between two values may be compared with a known or defined limit value. For example, should the value obtained be above the limit value, this may mean that a significant change in the degree of soiling is still taking place and the cleaning method must be continued. In another embodiment, should the limit value not have been reached over the course of a cleaning phase, this means that a significant change in the degree of cleaning is still taking place, such that a further cleaning phase is necessary. Depending on the measured parameter, not achieving the limit value may here mean that the limit value has been exceeded or fallen below. In one embodiment, the parameter at the point in time t2 itself provides information about the degree of cleaning.
If the measurement reveals during a cleaning operation that cleaning has to be continued, a subsequent or further cleaning phase may be carried out with the same parameters as the first or preceding cleaning phase. In another embodiment, however, the parameters of the cleaning operation or cycle are changed in response to the parameters obtained, such that for example the temperature, the additionally supplied quantity of cleaning agent or the duration of the subsequent cleaning phase is adapted to the progression in the parameters.
After a further time interval, a subsequent parameter may be or is determined, wherein the time interval may be identical to the first time interval between the determination of the parameters, as described above. By maintaining the time interval between the individual measurements, the degree of soiling or achieved degree of cleaning can be determined continuously and thus consistently. In one embodiment, the time interval for determining the subsequent parameter may be different from the preceding time interval, for example in response to the hitherto achieved degree of cleaning or degree of soiling still remaining.
In one embodiment, the parameters obtained, i.e. a plurality of parameters obtained over time, may be combined by the open- or closed-loop control device to yield a measurement curve, such that the progression thereof may be evaluated by suitable mathematical algorithms. For example, a statement about the degree of soiling or degree of cleaning can be made on the basis of the gradient of the curve, a derivative function, determination of maxima and/or minima or by specific filtering of the measured values. In one embodiment, a regression analysis of the parameters can be carried out. Irrespective of the nature of the calculation of the degree of soiling or degree of cleaning, further cleaning of the cooking appliance can be adapted in line with the result or the cleaning operation terminated, for example when the defined limit value or another measured value, as described above, is reached. As soon as the cleaning operation has been terminated, a rinsing phase, which may be carried out using the method, may follow.
The respective above-described measurement during a cleaning operation may also be carried out only once the pump has been stationary for a predetermined period, i.e. the cleaning operation has come to rest, such that the washing liquor comes to rest and the measurement(s) are not impaired by possible air bubbles or foam or other disruptive factors.
The present method also makes it possible to verify whether preceding cleaning phases have proceeded correctly. For example, by measuring a parameter during the rinsing phase it can be verified whether a cleaning agent has previously been supplied to the cooking appliance or the quantity of cleaning agent was sufficient. Depending on the measured parameter, the cleaning curve declines more slowly, for example, and remains at a low level if no cleaning agent has been added. Conclusions regarding preceding cleaning phases may thus be drawn from the respective parameters for a cleaning phase.
The present method thus makes it possible to determine the current degree of soiling of the cooking appliance during a cleaning operation by determining a physical variable of the washing liquor. This determination in turn permits automatic adaptation and control of cleaning temperature, duration of cleaning, the quantity of cleaning medium used and/or the chemistry and/or quantity of cleaning agent used. A further advantage may include that a plurality of different cleaning programs is not required, but instead the cooking appliance “autonomously” cleans itself optimally by adapting the cleaning parameters. Accordingly, the cleaning method can, for example, automatically determine the cleaning parameters on the basis of an initially determined parameter TS0.
If, for example, a cleaning operation is started with an environmentally friendly “eco” program, the degree of soiling is determined during the cleaning operation and, as a consequence, if a corresponding degree of soiling is present, additional cleaning agent can for example be supplied or higher cleaning temperatures used. Ultimately, the user is not required to select a suitable cleaning program, since the program can adapt itself to the required cleaning conditions.
In another aspect, a cooking appliance includes an interior and at least one sensor in the interior and/or downstream of the interior, in particular in a cleaning path, for carrying out the method.
Preferably, the cooking appliance is self-learning, thus it in particular uses the respectively ascertained degree of soiling to derive teaching for future operations and also for those under way.
In the case in which a degree of soiling is to be detected during a cooking operation, it is particularly preferred to arrange the sensor in a pump sump which forms a water reserve between the cooking chamber and the outlet of the cooking appliance. Locating the sensor in a condenser and/or cleaning tank arranged between the cooking chamber and the outlet is particularly advantageous for this purpose. In particular in the case of a turbidity sensor being used, it is preferred for the turbidity sensor to be arranged during acquisition of the pump sump parameters in the juices which flow out from the foodstuff during cooking thereof. The water level in the pump sump must therefore be controlled in such a manner that this is ensured.
In other words, a cooking appliance for detecting a degree of soiling during a cooking operation is distinguished in that the sensor is arranged downstream of the cooking chamber with the liquid to be evaluated flowing therearound.
Further, the cooking chamber may be connected, in particular with interposition of a strainer, to a condenser and/or a cleaning tank, and for the sensor to be arranged in the condenser and/or cleaning tank.
The condenser and/or cleaning tank may be connected to an at least temporarily closable outlet and/or to an at least temporarily closable return line to the cooking chamber.
It may here in turn be provided for the outlet to be temporarily closable via a pump or a valve, and/or the return line to be connected to a pump and/or a valve.
It is here preferred for the sensor to be arranged in the water reserve provided by a sump of the pump of the outlet and/or of the pump of the return line.
The sensor may be arranged in the water reserve between the cooking chamber and the outlet from the cooking appliance. The water level of the water reserve is preferably adjustable, in particular via an open- or closed-loop control device in operative connection with the pump of the outlet, the pump, the return line and/or a shut-off device.
A smart cleaning method for a cooking appliance may be provided, in which resources are optimally utilized and thus costs are saved and environmental impact is reduced while satisfactory cleaning performance is simultaneously achieved. This is achieved on the basis of the recognition that different parameters provide an indication about the degree of soiling of an interior, i.e. the severity of the cleaning task.
Further features and advantages of the invention are described by the following description which explains exemplary embodiments of a method according to the invention with reference to schematic diagrams.
The method is described by way of example on the basis of the determination of turbidity values of the washing liquor, wherein the method can be carried out in a similar manner for any other of the above-stated parameters or any combination of parameters. When a turbidity sensor is used, a low parameter for example means high turbidity, since voltage values are detected which are lower, the smaller the quantity of light is that passes through the washing liquor and impinges on a sensor due to the turbidity of the washing liquor.
After the start of a cleaning program and introduction of washing liquor into the cooking chamber of a cooking appliance, a cleaning phase is started which uses the cleaning parameters, such as for example a defined temperature with a predetermined cleaning agent.
The proportion of particles in the washing liquor and thus the degree of turbidity can be taken from
As is apparent from progression 1 in
The degree of soiling can thus in particular be inferred from the minimum of the turbidity value progression. The lower the detected voltage value at the minimum during the turbidity value progression, the greater is the degree of soiling.
During a cleaning method, washing liquor 26, which can be introduced into the cleaning tank 24 with a determined water level 27, is conveyed from the cleaning tank 24 into the cooking chamber 10 by means of the circulating pump 42 in order to carry out cleaning. The washing liquor flows out of the cooking chamber 10, passing through the strainer 14 and back into the cleaning tank 24. The washing liquor 26 is thus circulated.
During a cooking method, instead of the washing liquor 26 shown in
A turbidity sensor 28 is arranged in the cleaning tank 24. The position of the turbidity sensor 28 is selected such that, during a cleaning method, the washing liquor 26 flows effectively around it and, that during a cooking method, a location below the water level 27 of the pump sump is ensured. The turbidity sensor 28 need not necessarily be fastened for this purpose to the bottom of the cleaning tank 24 but can also be provided in a wall. The position in the bottom shown in
The water level 27 can be controlled by means of the wastewater pump 32, or alternatively via an outlet valve (e.g. ball valve), a defined drain orifice or the like.
In the cooking appliance 1 of
If turbidity values are detected for example during a cooking method, it is possible to draw a conclusion therefrom about the soiling of the cooking chamber 10 which is dependent on the quantity and nature of the foodstuff being cooked. On the basis of the determined degree of soiling, it is then in turn possible to determine a suitable cleaning method which is to proceed later. This cleaning method can be output as a suggested cleaning program, either on a display means on the cooking appliance 1 or on a central control console of a kitchen network into which the cooking appliance can be integrated. The display may for example appear after completion of the cooking operation automatically or only on request.
In a further embodiment, after introduction of the washing liquor into the cooking chamber of a cooking appliance, in which foodstuffs can in particular be exposed to hot air, steam and/or microwaves, a cleaning operation is started either automatically after determination of a parameter T0 at a point in time t0 or by selection of a cleaning program by a user. Automatic determination or manual selection of the cleaning program also results in the selection of cleaning parameters, such as for example a predetermined temperature and a cleaning product chemistry to be used. If the cleaning program comprises a plurality of cleaning phases, the cleaning parameters are provisionally selected for all cleaning phases.
Relatively shortly after the start for example of a first cleaning phase, a first turbidity value TS1 is determined at a first point in time t1 by means of one or more sensor(s) present in the cooking chamber. Then, at a predetermined second point in time t2, the current turbidity of the washing liquor is determined, thus a second turbidity value TS2 is determined. On the basis of the two turbidity values, a first difference is then determined: ΔTS1=TS2−TS1. The difference value determined in this manner is then compared with a predetermined first limit value. If, for example, the first limit value is exceeded, i.e. ΔTS1>TSlimit, a second cleaning phase is started. After an identical time interval has elapsed, a third turbidity parameter TS3 is detected and a second difference, i.e. ΔTS2=TS3−TS2, determined and compared with the first or a second limit value. Should the limit value again be exceeded, i.e. ΔTS2>TSlimit, a third cleaning phase begins automatically. In the example in
Selection of the cleaning program is non-critical in a method because the cleaning phases of the particular cleaning operation which has been started are automatically adapted. This enables the provision of a cooking appliance with only one cleaning program, which is preferably an environmentally friendly “eco” program which for example requires additional cleaning agent and/or elevated temperatures only in the case of a respective degree of soiling. In one embodiment, the cooking appliance itself determines the cleaning program, i.e. the cleaning parameters, by ascertaining the initial turbidity value.
In addition, the cooking appliance may also be self-learning, since it can store changed cleaning parameters for future cleaning operations. A linkage to cooking programs can also be made by correlating the detected degree of soiling with the cooking program(s) which has/have previously been run.
The features of the invention disclosed in the above description, in the claims and in the drawings may be of significance for implementation of the invention in its various embodiments either individually or in any desired combination.
1 Cooking appliance
10 Cooking chamber
12 Drain
14 Strainer
16 Fan wheel
20 Condenser
22 Connecting line
24 Cleaning tank
26 Washing liquor
27 Water level
28 Turbidity sensor
30 Outlet
32 Wastewater pump
40 Return line
42 Circulating pump
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2017 111 249.9 | May 2017 | DE | national |
| 10 2017 111 246.4 | May 2018 | DE | national |
