Method for cleaning a steam generator of a cooking appliance and a cooking appliance with a steam generator

Abstract

The invention relates to a method for cleaning a steam generator (18) of a cooking appliance (10), comprising a tank (22) and a heating device (24) for heating a liquid inside the tank (22). In a first step, a cleaning solution is introduced into the tank (22) so that it is filled with the cleaning solution up to a maximum fill line (30). In a second step, the cleaning solution is heated to below its boiling point. In a third step, the cleaning solution is heated further until a first sensor (44) detects an overflow signal, which is representative of a portion of the cleaning solution overflowing from the tank (22) of the steam generator (18) into an interior of the cooking appliance (10). In a fourth step, the heating power of the heating device (24) is reduced.

Description

[0001] The invention relates to a method for cleaning a steam generator with a cooking appliance, a tank, and a heating device for heating a liquid inside the tank. The invention also relates to a cooking appliance with a steam generator with a tank and a heating device for carrying out the method.

[0002] In large-scale or professional kitchens, cooking appliances are used that have a steam generator that produces steam to steam and cook food in a cooking chamber. The steam generator is connected to the cooking chamber via a pipe, through which the steam generated in the steam generator is fed into the cooking chamber. Inside the steam generator, a liquid stored in a tank, typically water, which can optionally be flavored, evaporates. To heat the water, the steam generator has a heating device that heats the water to boiling, creating steam. A resistance heater or an immersion heater is typically used as the heating device.

[0003] Depending on the hardness of the water used, deposits of the substances dissolved in the water, such as limescale, can occur sooner or later. The evaporation of the water, particularly due to turbulence when the water boils, leads to limescale deposits above the fill level. In addition, while food is cooking in the cooking chamber, fats, for example, get into the steam generator via the line. These deposits can settle on the walls of the tank, in the line, or on the surface of the heating device. As a result of the deposits in the line between the steam generator and the cooking appliance, the line can, in the worst case, become almost completely blocked by the deposits. Deposits on the heating device mean that the water can only be heated inhomogeneously, which in turn leads to bubbling or bubbling of the water being evaporated.

[0004] Overall, the performance of the steam generator is reduced by such deposits,

[0005] Until now, such deposits have been removed using special cleaning programs such as descaling. However, these cleaning programs cannot remove deposits above the water surface in the tank or deposits in the pipes. Even greasy deposits in the pipes cannot be removed with these cleaning programs.

[0006] The object of the invention is to provide a method with which deposits, in particular deposits in the tank above the water level and deposits in the line between the steam generator and the cooking chamber, can be removed.

[0007] The object is achieved according to the invention by a method for cleaning a steam generator of a cooking appliance, comprising a tank and a heating device for heating a liquid inside the tank, wherein the method comprises the following steps: In a first step, cleaning solution is introduced into the tank so that it is filled with a cleaning solution up to a maximum fill level line. In a second step, the cleaning solution is heated to below a boiling point of the cleaning solution. Subsequently, in a third step, the cleaning solution is further heated until a first sensor detects an overflow signal which is representative of overflow of a portion of the cleaning solution from the tank of the steam generator into the interior of the cooking appliance. In a fourth step, the heating power of the heating device is then reduced.

[0008] The process is based on the basic idea that, during the steam generator cleaning process, the cleaning solution, especially the descaling solution, is "carefully" boiled so that only a small amount of the cleaning solution from the steam generator enters the interior of the cooking appliance, i.e., the cooking chamber. Boiling over the cleaning solution also removes limescale and grease deposits located above the liquid level. This "careful"—i.e., controlled and precisely directed—boiling over of the cleaning solution prevents excessive amounts of the cleaning solution from entering the cooking chamber, thus making it unavailable in the steam generator.

[0009] As soon as a sensor detects one of the overflow signals, the heating element's heat output is reduced so that no more cleaning solution overflows from the steam generator into the cooking chamber. The heating output can be reduced either for a short time or the heating element can be switched off permanently. This ensures that only very small amounts of cleaning solution enter the cooking chamber. This is important because vigorously boiling the cleaning solution would remove a large amount of water from the steam generator. Furthermore, the cooking chamber would have to be extensively cleaned after cleaning the steam generator to remove all cleaning solution residues from the cooking chamber.

[0010] The cleaning solution can be further heated either continuously, i.e., constantly, or gradually with short heating breaks between individual heating periods. If the heating is continued continuously, the heating power is significantly reduced compared to gradual heating to prevent excessive and rapid overflow of the cleaning solution into the cooking chamber. Furthermore, it is advantageous if the first sensor is installed inside the steam generator, and in particular, a particularly sensitive sensor is used that can detect the overflow signal very quickly. If the heating is continued gradually, the heating power can be increased and a less sensitive sensor can be used.During gradual heating, the heating output is automatically reduced after a device-specific time. Depending on whether an overflow signal was detected by the first sensor, the heating output is increased again after a short period of time or remains reduced for a longer period. The overflow signal can be detected by the first sensor either during the heating phase or, preferably, during the heating pause.

[0011] In the following, "overflow" refers to the condition in which even the smallest amounts of cleaning solution have passed from the steam generator through the line into the interior of the cooking chamber. As long as no liquid has entered the cooking chamber, there is no overflow of the cleaning solution. Overflowing a portion of the cleaning solution is desirable, as it ensures that the cleaning solution has risen to the very top of the steam generator, thus cleaning the area above the fill line.

[0012] The small amounts of overflowed cleaning solution can advantageously be used for subsequent cleaning of the cooking chamber, for example for rinsing the cooking chamber.

[0013] The process also offers the advantage that, with regular use, the upper area of ​​the steam generator tank and the line to the cooking chamber can be kept permanently free of deposits, especially limescale and grease. A layer of limescale in this area often absorbs dirt or cleaning solutions, promotes corrosion, and, in the worst case, restricts the steam flow from the steam generator to the cooking chamber. Therefore, for heavily calcified steam generators, the only option is usually to replace them. However, with regular use of the process, this can be prevented.

[0014] The process also offers the advantage of eliminating the need for very strong descaling agents, such as scale removers, which are typically used to descale steam generators. These scale removers have the disadvantage that they generate corrosive fumes and, if used over a long period of time, lead to corrosion of the metal in the cooking chamber if the scale remover boils over into the cooking chamber. The process according to the invention eliminates the need for such strong descaling agents, as the steam generator and the pipework are successfully freed of deposits.

[0015] According to one aspect of the invention, the overflow signal is an increase in the temperature in the steam generator, a reduced level of the cleaning solution in the tank, an increase in the power of a fan wheel arranged between the cooking chamber and the steam generator and / or an increase in the cooking chamber temperature inside the cooking appliance.

[0016] The overflow signal is only detected by the first sensor if a portion of the cleaning solution overflows from the steam generator into the cooking chamber. If no overflow occurs, the first sensor will not detect an overflow signal.

[0017] Depending on the overflow signal to be detected, the sensor is either a temperature sensor, a level sensor or a power meter.

[0018] Both an increase in the temperature in the steam generator and an increase in the cooking chamber temperature, especially an increase of at least 0.8°C, are signs that cleaning solution has entered the cooking chamber. A sudden increase in the power of the running fan wheel, where the power is measured at a constant speed, also indicates an overflow of the cleaning solution, as the cleaning solution slows down the fan wheel during the overflow, which is noticeable by a brief increase in the power of the fan wheel. A reduced fill level of the cleaning solution in the steam generator tank, especially the amount of water with which the tank must be refilled to the maximum fill level, is also an overflow signal.

[0019] The cleaning solution that is introduced into the tank in the first step is an aqueous solution of cleaning agent and water, which can be introduced directly into the steam generator tank and / or indirectly into the steam generator tank during a cleaning process of the cooking chamber.

[0020] In other words, the cleaning solution can either be deliberately and directly introduced into the steam generator tank, or it can enter the steam generator unknowingly and indirectly by entering the steam generator tank via the pipe during a cleaning process of the cooking chamber. In both cases, the cleaning solution contained in the steam generator tank can be used for the steam generator cleaning process. The crucial thing is that there is a sufficient amount of cleaning agent in the tank so that the cleaning solution contains a sufficient concentration of cleaning agent. The lower the cleaning agent concentration in the cleaning solution, the more difficult it is to boil the cleaning solution to the point where it rises to the top of the steam generator and the cleaning solution overflows into the cooking chamber.The filling level of the cleaning solution is not above the maximum filling level line or above a vent pipe of the steam generator.

[0021] According to a further aspect of the invention, the second step of the method comprises the following steps: first, the cleaning solution is heated with the heating device. Then, in a third step, the heating power of the heating device is reduced, and then an actual temperature of the cleaning solution is measured with a temperature sensor. These three steps are repeated until the actual temperature of the cleaning solution substantially corresponds to the boiling point of the cleaning solution.

[0022] In particular, the temperature before heating in the second step is between 70 and 90°C.

[0023] The boiling point is the temperature at which a liquid substance, in this case the cleaning solution, changes into the gaseous state.

[0024] The already warm cleaning solution is heated gradually or in stages according to the process. For this purpose, the heating device is preferably switched on for one to a few seconds and immediately afterwards the heating power is reduced for a few seconds. The heating device can also be switched off completely. Reducing the heating power is crucial to prevent delayed boiling. After the heating power has been reduced or the heating device has been switched off, the actual temperature of the cleaning solution is measured using a temperature sensor. The actual temperature is thus measured at a time when the cleaning solution is not being heated or is not being heated at full heating power. For example, the heating power of the heating device can be halved or the heating power can be modulated between 0 and 100%.

[0025] Gradually heating the cleaning solution ensures that it is heated "carefully." This prevents the cleaning solution from heating up too quickly to boiling temperature, which would cause excessive foaming and excessive overflow of the cleaning solution into the cooking chamber.

[0026] Heating in the second step only takes place until the actual temperature of the cleaning solution is just below its boiling point, so that the cleaning solution does not yet boil, especially not bubble. The boiling point depends on the specific cleaning solution and the concentration of cleaning agent it contains.

[0027] In the third step of the process, the cleaning solution is further heated by alternately increasing and reducing the heating power of the heating device.

[0028] In this step, the heater is also briefly switched on for one to a few seconds and then immediately switched off again for a few seconds, creating a heating pause. Of course, the heater's heat output can also be reduced, but switching it off is preferred.

[0029] Gradual heating with heating pauses has the advantage of allowing the cleaning solution to boil over and over in a controlled manner. By removing the heat, the cleaning solution does not boil continuously, but only briefly, so that even small amounts of the cleaning solution only temporarily overflow into the cooking chamber. This also prevents excessive foaming of the cleaning solution. Furthermore, the heating pauses prevent a delayed overflow caused by a delayed boiling of the cleaning solution. If such a delayed boiling of the cleaning solution should occur, the first sensor can detect an overflow signal during the heating pause, and the heating power is reduced for a longer period in step 4.

[0030] One aspect of the invention provides that steps 2 to 4, in particular steps 3 to 4, are repeated until a termination condition is met, wherein after the termination of the method the tank of the steam generator is emptied.

[0031] The process is repeated until the cleaning fluid overflows, especially several times. This ensures that the area of ​​the tank above the fill line, as well as the line between the steam generator and the cooking chamber, is completely free of limescale and grease deposits.

[0032] The termination condition can be a number of overflows, a liquid volume, in particular the liquid volume that must be refilled into the tank to reach the maximum fill level, a period of time, the temperature of the steam generator, and / or the amount of energy supplied to the steam generator during the cleaning process. The period of time is, in particular, ten minutes. Another termination condition is the temperature of the steam generator, in particular a temperature limit that represents overheating of the steam generator.

[0033] Several completion conditions can be met at the same time, but the procedure will end as soon as at least one completion condition is met.

[0034] Once the process is complete, the steam generator is emptied via a pump and fresh water is only added when a minimum fill level is reached. While the water filling is switched on, the pump continues to run so that targeted and optimal flushing of the pump is achieved. This also ensures that not only the tank and the steam generator line are completely free of all residues, but also that a water column in a bypass of the steam generator, which still contains dissolved impurities that would flow back into the tank if the pump was switched off, is flushed out. This emptying therefore ensures that the entire steam generator, including the bypass, is completely free of residues and cleaned. Once all parts of the steam generator have been cleaned, the pump is switched off and the steam generator is completely filled with fresh water.

[0035] According to the invention, at least one of the following process parameters is measured during the process with a second sensor over a period of time, in particular over the entire duration of the process. The process parameters can be: the temperature in the steam generator, the heating power of the heating device, the amount of energy supplied to the heating device, and / or the fill level of the cleaning solution in the tank.

[0036] According to one aspect of the invention, an evaluation unit evaluates at least one of the process parameters and sends a signal to a control unit, wherein the control unit controls the heating device based on the signal such that the temperature of the cleaning solution in the steam generator is kept below the boiling temperature of the cleaning solution.

[0037] Based on the temperature profile over a period of time in the steam generator, as well as the heating time and heating power required from previous cleaning processes to heat the cleaning solution to just below the boiling point, it is possible for the control unit to specifically control the heating device so that it only heats until the temperature of the cleaning solution is just before its boiling point and the cleaning solution is therefore just about to overflow.

[0038] Such a self-learning, adaptive process offers, among other things, the advantage that in the second step of the process, the actual temperature of the cleaning solution in the steam generator does not have to be constantly monitored.

[0039] The invention also relates to a cooking appliance with a steam generator having a tank and a heating device for carrying out the method, wherein the cooking appliance has a first sensor for measuring at least one overflow signal, a second sensor for measuring at least one process parameter, an evaluation unit for evaluating the process parameter and a control unit for controlling the heating device.

[0040] The cooking appliance according to the invention is characterized in that it can carry out the method for cleaning the upper area of ​​the tank of the steam generator and the line between the steam generator and the cooking chamber, wherein the cleaning solution in the tank of the steam generator is "carefully" boiled step by step until small amounts of cleaning solution overflow into the cooking chamber.

[0041] Further advantages and features of the invention will become apparent from the following descriptions, exemplary embodiments, and the drawings, in which: - Fig. 1 a schematic side view of a cooking appliance according to the invention for carrying out the method according to the invention; - Fig. 2 a schematic representation of the cleaning process according to the invention.

[0042] In Fig. 1 shows a cooking appliance 10 having a cooking chamber 12 in which food can be cooked. The cooking appliance 10 is a professional cooking appliance, such as those used in restaurants, canteens, and large-scale catering. It is capable of cooking the food in the cooking chamber 12 using hot air and / or steam. A microwave generator for generating microwave radiation can also be present. Various cooking programs can be executed in the cooking appliance, with which the food can be cooked either according to a user's specifications, semi-automatically, or fully automatically.

[0043] In the cooking chamber 12, food can be cooked in a cooking chamber atmosphere whose key parameters are temperature, air flow rate, and humidity. Temperature and air flow rate can be adjusted using a heating device and a fan impeller 14. The cooking chamber 12 can be closed with a cooking chamber door 16 to maintain the cooking chamber atmosphere.

[0044] The cooking appliance 10 has a steam generator 18. The steam generator 18 serves to generate steam, which can be introduced into the cooking chamber 12 via a line 20. The fan wheel 14 is located at the cooking chamber end of the line 20, so that the steam generated by the steam generator 18 passes through the fan wheel 14 into the cooking chamber 12 and is distributed by it.

[0045] The steam generator 12 has a tank 22 in which a liquid, in particular water or a cleaning solution, can be brought to a boil, thus generating steam. The tank 22 is made, in particular, of metal.

[0046] To remove residues, such as limescale or grease residues, in the tank 22 of the steam generator 18, a cleaning solution can be introduced into the tank 22. This cleaning solution is an aqueous solution of cleaning agent and water. The cleaning agent can either be introduced into the tank externally by a user of the cooking appliance 10, or the cleaning agent can enter the interior of the tank 22 indirectly via the line 20 during cleaning of the cooking chamber 12.

[0047] Regardless of how the cleaning agent got into the tank 22, it can be used to clean the area of ​​the tank 22 above the liquid level 23 and thus to remove limescale and grease deposits.

[0048] A heating device 24 is provided in the tank 22 for heating the liquid and generating steam. The heating device 24 is, for example, an electric resistance heater or an immersion heater.

[0049] The actual temperature of the liquid in the tank 22 of the steam generator 12 is measured by a temperature sensor 26. This temperature sensor 26 is connected to a control unit 27 for information exchange and can send a signal representative of the actual temperature of the cleaning liquid to the control unit 27.

[0050] The control unit 27 serves to control the heating device 24. In particular, the heating power of the heating device 24 is controlled via the control unit 27 such that, in the second step of the process, a cleaning solution temperature is achieved that is just below the boiling point of the cleaning solution. The cleaning solution does not yet boil, i.e., it does not fizz or bubble.

[0051] Only in the third step of the process is the heating device 24 controlled by the control unit 27 so that the cleaning solution in the tank 22 boils and consequently overflows via the line 20 into the cooking chamber 12.

[0052] The steam generator 18 has a water inlet 28 in a side wall, through which fresh water can be refilled into the tank. In particular, the water inlet 28 is located below a maximum fill level line 30 of the tank 22. The maximum fill level line 30 indicates the maximum permissible fill level 23 of the tank, which must not be exceeded.

[0053] To carry out the cleaning process, the tank 22 must be filled with cleaning solution up to the maximum fill level line 30 so that the fill level 23 is on the maximum fill level line 30.

[0054] Above the maximum fill level line 30 there is a vent pipe 32 which must not be below the liquid level.

[0055] Line 20 is also located above the maximum fill level line 30. The tank 20 of the steam generator 18 must not be filled to the point where liquid enters the cooking chamber 12 via line 20.

[0056] The tank 22 also has a minimum fill level line 34 which indicates the liquid level below which the liquid level must not fall in order to avoid damage to the heater 24 or other components of the steam generator 18.

[0057] The liquid in tank 22 can be pumped out of tank 22 via a pump 36 and a drain 38. Drain 38 is designed to have two interconnected channel sections 40, 42. The first, steam generator-side channel section 40 extends from the lower section of the steam generator upwards to a level above the maximum fill level line 30 in tank 22. From this level, the second channel section 42 of the drain leads downwards. The two channel sections 40, 42 merge into one another. The transition lies above the maximum fill level line 30 of tank 22. The liquid level in the first channel section 40 corresponds to the water level in tank 22.

[0058] Located inside the steam generator 18 is a first sensor 44 that detects an overflow signal. However, the first sensor 44 can also be located in the cooking chamber 12 and detect an overflow signal there. For example, an increase in temperature in the steam generator 18 and a reduced level of cleaning solution in the tank 22 are detected by a first sensor 44 located in the steam generator 18, while an increase in the power at the fan impeller 14 or an increase in the cooking chamber temperature inside the cooking appliance 10 are detected by a first sensor 44 located in the cooking chamber 12.

[0059] Both the cooking chamber 12 and the steam generator 18 may have a second sensor 46 that can measure one or more process parameters.

[0060] The second sensor 46, which is mounted in the steam generator 18, can be, for example, a temperature sensor that measures the temperature in the steam generator. It is also possible for the second sensor 46 to measure the current fill level of the tank 22. Alternatively, the second sensor 46 can be designed as a power meter and detect the heating power of the heating device as well as the amount of energy supplied to the heating device.

[0061] Regardless of the design of the second sensor 46, the second sensor 46 measures a process parameter over a period of time, in particular over the entire duration of the process. In principle, it is also possible for the second sensor 46 not to record a complete temporal profile of the signal, but rather to perform several individual measurements at a defined time interval.

[0062] Both the first sensor 44 and the second sensor 46 are connected to the control unit 27 for signal transmission. The control unit 27 is in turn connected to an evaluation unit 48, which evaluates the signals sent by the first sensor 44 and the second sensor 46.

[0063] The signal measured by the two sensors 44, 46 is sent to the control unit 27 and evaluated by the evaluation unit 48. The evaluation unit 48 then sends a signal back to the control unit 27, based on which the control unit 27 activates the heating device 24. The control unit 27 controls the heating device 24 such that short heating phases are followed by heating pauses during which either the heating output of the heating device 24 is reduced or the heating device 24 is switched off. The temperature of the cleaning solution in the steam generator 18 is brought from approximately 70°C to 90°C to a value just below the boiling point of the cleaning solution and, if necessary, maintained there.

[0064] During this step, the control unit 27 receives a signal from the temperature sensor 26, either continuously or at regular intervals, which is representative of the actual temperature of the cleaning solution.

[0065] However, it is also possible that the control unit 27, based on an adaptive method, already knows, for example, the exact heating power, heating duration or the temperature profile over the heating duration from previous cleaning runs and the signals of the second sensor 46, so that the control unit 27 can control the heating device 24 and adjust the temperature of the cleaning solution accordingly even without a signal from the temperature sensor 26.

[0066] In the third step, the control unit 27 controls the heating device 24 again. This time, the heating device 24 heats the cleaning solution for a few seconds, after which the power of the heating device 24 is reduced or the heating device 24 is switched off completely by the control unit 27. Heating during the heating phases causes the cleaning solution to boil and subsequently overflow. This causes the cleaning solution to reach the areas of the tank 22 that are above the maximum fill level line 30, as well as into the line 20 and subsequently into the cooking chamber 12, where these areas are cleaned of limescale and / or grease residues.

[0067] However, by introducing heating pauses by the control unit 27, the cleaning liquid is not heated so quickly and intensely that it bubbles or foams and thus large quantities of cleaning solution enter the cooking chamber 12, so that a complex cleaning of the cooking chamber 12 is avoided.

[0068] As soon as one of the final conditions is reached and the cleaning agent has overflowed sufficiently often, the cleaning process is terminated and the control unit 27 switches off the heating device 24.

[0069] The deposits dissolved during the process remain in the cleaning solution after the cleaning process is completed. To remove the cleaning solution, it is passed through drain 38.

[0070] The drain 38 may also contain limescale deposits, so to completely remove all residues, the steam generator 18 is emptied via the pump 36 until a fill level 23 reaches the maximum fill level line 34. New water is then fed into the tank 22 through the water inlet 28.

[0071] The overflowed cleaning solution located inside the cooking chamber 12 can either be used for a cleaning process of the cooking chamber 12 or the cooking chamber 12 must be cleaned of the residues using a different cleaning solution.

[0072] Fig. 2 shows the cleaning method for cleaning the tank 22 of the steam generator 18 of the cooking appliance 10 and the line 20 between the cooking generator 18 and the cooking chamber 12.

[0073] In a first step S1, cleaning agent and water are introduced into the tank 22 of the steam generator 18 to produce a cleaning solution. The tank 22 is filled with the cleaning solution up to the maximum fill level line 30. The temperature of the cleaning solution is, in particular, already 70°C to 90°C.

[0074] In a second step S2, the heating device 24 is briefly switched on via the control unit 27, in particular for one to a few seconds. This is followed by the switching off of the heating device 24 or the reduction of the heating power of the heating device 24 by the control unit 27 for a few seconds. While the heating power of the heating device 24 is interrupted or reduced, the actual temperature of the cleaning solution in the tank 22 is determined via a temperature sensor 26 in a third step S3. If the actual temperature of the cleaning solution is well below the boiling point of the cleaning solution, step 2 is repeated.

[0075] If the actual temperature of the cleaning solution approximately corresponds to the boiling point of the cleaning solution, a fourth step S4 follows, in which the heating device 24 is switched on again for one to a few seconds, so that the cleaning solution is further heated. After one to a few seconds, the control unit 27 switches off the heating device 24 or at least reduces the heating power of the heating device 24, resulting in a heating pause for a few seconds.

[0076] In a fifth step S5, the first sensor 44 is used to check whether an overflow signal is present. The first sensor 44 only detects the overflow signal if cleaning solution has actually flowed from the steam generator 18 into the cooking chamber 12 via line 20. If this is the case, step S6 follows; otherwise, steps S4 and S5 are repeated until the first sensor 44 detects an overflow signal.

[0077] In step S6, a check is made to determine whether one of the final conditions is met. If at least one of the final conditions is met, step S7 follows, which terminates the cleaning program. If a final condition is not yet met, the process is repeated starting from step 4 until a final condition is met. After the process is completed, the tank 22 of the steam generator 18 and the line 20 are completely free of limescale deposits and grease residues.

Claims

[1] Method for cleaning a steam generator (18) of a cooking appliance (10), having a tank (22) and a heating device (24) for heating a liquid inside the tank (22), the method comprising the following steps:

1. Introducing a cleaning solution into the tank (22) so that it is filled with a cleaning solution up to a maximum fill level line (30); 2. Heating the cleaning solution to below the boiling point of the cleaning solution; 3. Further heating of the cleaning solution until a first sensor (44) detects an overflow signal which is representative of an overflow of a part of the cleaning solution from the tank (22) of the steam generator (18) into an interior of the cooking appliance (10); 4. Reducing the heating power of the heating device (24). [2] Method according to claim 1, characterized bythat the overflow signal is an increase in the temperature in the steam generator (10), a reduced fill level (23) of the cleaning solution in the tank (22), an increase in the power of a fan wheel (14) arranged between the cooking chamber (12) and the steam generator (18) and / or an increase in a cooking chamber temperature of the interior of the cooking appliance (10). [3] Method according to claim 1 or 2, characterized by that the cleaning solution in step 1 is an aqueous solution of cleaning agent and water, which is introduced directly into the tank (22) of the steam generator (18) and / or enters the tank (22) of the steam generator (18) during a cleaning process of the cooking chamber (12). [4] Method according to one of the preceding claims, characterized by that step 2 of the procedure includes the following steps: a) heating the cleaning solution with the heating device (24); b) reducing the heating power of the heating device (24); c) measuring an actual temperature of the cleaning solution with a temperature sensor (26); d) Repeat steps a) to c) until the actual temperature of the cleaning solution substantially corresponds to the boiling temperature of the cleaning solution. [5] Method according to one of the preceding claims, characterized by that in step 3 of the method for further heating the cleaning solution, the heating power of the heating device (24) is alternately increased and reduced. [6] Method according to one of the preceding claims, characterized by that steps 2 to 4, in particular steps 3 to 4, are repeated until at least one termination condition is met, wherein after the end of the method the tank (22) of the steam generator (18) is emptied. [7] Method according to one of the preceding claims, characterized bythat the final condition is a number of overflows, a liquid volume, in particular the liquid volume that is refilled into the tank (22) to reach the maximum fill level (23), a period of time, the temperature of the steam generator (18) and / or the amount of energy that was supplied to the steam generator (18) during the cleaning process. [8] Method according to one of the preceding claims, characterized by that during the process at least one of the following process parameters is measured with a second sensor (46) over a period of time, in particular over the entire duration of the process: temperature in the steam generator (18), heating power of the heating device (24), amount of energy supplied to the heating device (24), and / or fill level (23) of the cleaning solution in the tank (22). [9] Method according to claim 8, characterized bythat an evaluation unit (48) evaluates the at least one process parameter and sends a signal to a control unit (27), wherein the control unit (27) controls the heating device (24) based on the signal such that the temperature of the cleaning solution in the steam generator (18) is kept below the boiling temperature of the cleaning solution. [10] Cooking appliance (10) with a steam generator (18) with a tank (22) and a heating device (24) for carrying out the method according to one of the preceding claims, characterized by that the cooking appliance (10) has a first sensor (44) for measuring at least one overflow signal, a second sensor (46) for measuring at least one process parameter, an evaluation unit (48) for evaluating the process parameter and a control unit (27) for controlling the heating device (24).

Images