Cleaning device, and method for controlling a cleaning device taking scaling into consideration
Patent Information
- Application Number
- EP2024702543
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-02
- Filing Date
- 2024-01-30
- Publication Date
- 2025-12-10
AI Technical Summary
Existing cleaning devices face inefficiencies due to calcification of heating elements, leading to reduced steam generation and cleaning effectiveness, as they lack real-time monitoring and appropriate descaling recommendations, resulting in either unnecessary descaling or delayed maintenance.
A cleaning device with a control unit that measures electrical power consumption to indirectly determine calcification levels, using reference curves to assess the degree of calcification and provide timely descaling recommendations without adding complexity or cost, utilizing a temperature-controlled heating device with a bimetal switch or microcontroller for efficient operation.
Ensures long-term functionality and high cleaning performance by accurately determining calcification and prompting necessary descaling, avoiding unnecessary maintenance and maintaining optimal steam generation.
Smart Images
Figure EP2024052151_08082024_PF_FP
Abstract
Description
[0001] Cleaning device and method for controlling a cleaning device taking into account calcification
[0002] Description
[0003] The invention relates to a cleaning device comprising a liquid container, a current-driven heating device for heating a liquid, and a control unit for controlling the device. The invention also relates to a method for operating such a cleaning device.
[0004] State of the art
[0005] A wide variety of cleaning devices are available for cleaning surfaces such as floors. A particularly effective method for cleaning hard surfaces is the use of steam. For example, WO 2016 / 046 554 A1 describes a steam cleaning device that has a steam generator and a cleaning element. Steam is applied to the contact area between the cleaning element and the surface to be cleaned. To heat the water in a container and generate steam, the steam generator has a heating device, such as a boiler.
[0006] The cleaning device can only be used for cleaning when the operating temperature has been reached and a sufficient amount of steam is generated. For this purpose, it is known in the art to supply the heating device with electrical current in a timed manner, thus activating it so that, for example, a temperature in the range between 150 and 220°C is maintained.
[0007] Household appliances with a liquid container and heating device that are similar to cleaning devices such as steam cleaners include irons, steamers and coffee machines.
[0008] Depending on the quality of the water used, particularly its hardness, limescale deposits can form on the heating element of the cleaning device. As limescale builds up on the boiler, heat transfer and thus the heating of the water deteriorates. The limescale deposits form an insulating layer on the surface of the boiler, which is in contact with the water being heated. The water can then be heated at a lower temperature or in smaller quantities. If steam is generated by the heating element, the amount of steam available is reduced or the water is not completely evaporated. This can, in turn, reduce the cleaning effect of the cleaning device.
[0009] Therefore, it is common practice for household appliances and cleaning devices to be descaled regularly, for example, using citric acid after a certain period of use or depending on the water hardness. The water hardness can be stored in the control unit by the appliance operator. The cleaning device can then prompt the appliance operator to descale, for example, using a warning light or an acoustic warning.
[0010] This state-of-the-art solution fails to take into account the actual calcification of the heating system and the actual need for descaling. This can result in unnecessary descaling or even occur too late to ensure the long-term reliable operation of the cleaning device.
[0011] It would therefore be desirable to determine the actual calcification and, based on this, to be able to provide recommendations for decalcification. However, a direct measurement of the degree of calcification is not feasible without reasonable effort.
[0012] It is generally known from the prior art to equip household appliances with sensors for monitoring and controlling them. It is also possible to equip the household appliance with a temperature sensor and monitor the boiler temperature. The boiler temperature can be used to determine the degree of calcification. Thus, the degree of calcification can be indirectly determined by measuring the temperature. Such a solution is pursued in EP 0 947 767 A2. Alternatively, the water temperature and / or the water or steam flow rate could be measured. A solution for the latter approach is described in US Pat. No. 7,966,683 B2.
[0013] However, the disadvantage of such solutions with an additional sensor, in addition to the cost and integration effort for the additional sensor, is that complex insulation of the lines is required. The sensor lines in the boiler area would have to be thermally stable, meaning a more expensive material with a high melting temperature would have to be used. Otherwise, there would be a risk of short circuits once the lines melted. Such a solution therefore entails a greater complexity in the design of the cleaning device and higher costs.
[0014] The object of the present invention is to create a cleaning device and to describe a method for operating a cleaning device, wherein the required descaling can be initiated depending on the degree of calcification of the heating device, and the cleaning device's construction does not become more complex, thus at least partially eliminating the disadvantages of the prior art. This is intended to ensure long-term functionality and high cleaning performance of the cleaning device.
[0015] Technical solution
[0016] This object is achieved by a cleaning device and a method for operating a cleaning device as described and claimed below.
[0017] According to the invention, it was recognized as advantageous to compare the electrical energy consumption of the heating device with a trend value previously stored in the control unit.
[0018] The cleaning device is equipped with a cleaning element, a liquid container, a current-driven, temperature-controlled heating device, particularly with a steam generator, for heating a liquid, and a control unit for controlling the heating device. The cleaning device is connected to a power source such as a household outlet. Alternatively, it could have a battery. A temperature-controlled heating device means that the heating device maintains a fixed or predetermined temperature range and is switched on and off in such a way that current is applied to maintain this temperature range between the lower and upper switching temperatures.
[0019] If necessary, the cleaning device may be provided with a pump for transporting the liquid, which transports the liquid from the liquid container to the heating device.
[0020] According to the invention, the control unit has a device for determining the electrical power consumption of the heating device or a variable proportional thereto and at least one reference curve stored in the control unit for the course of the electrical power consumption of the heating device or a variable proportional thereto. The reference curves can be determined in tests and stored during production before the cleaning device is sold. The reference curves represent the course of the electrical power consumption of the heating device or a variable proportional thereto over time. It has been found that the electrical power consumption of the temperature-controlled heating device or a variable proportional thereto is inversely proportional to the degree of calcification of the heating device. With increasing calcification of the heating device, e.g.On the surface of a boiler, limescale forms an insulating layer on the heating element because the thermal conductivity of limescale is poorer than that of the material used in the heating element. For example, aluminum, which has good thermal conductivity, is often used on the surface of a boiler.
[0021] Due to the increasing insulating layer and insulating effect of the limescale, the heat transfer from the heating device to the cleaning fluid deteriorates. The heating device thus retains heat longer and needs to be activated less frequently to maintain the specified or predefined temperature range, which reduces the electrical power consumption of the heating device or a value proportional to it. The degree of limescale buildup can thus be determined from the electrical power consumption of the heating device or a value proportional to it, and the degree of limescale buildup is determined by an indirect measurement. Such a solution can be implemented simply and cost-effectively.
[0022] In a particularly advantageous and therefore preferred cleaning device, the heating device can be operated at a constant heat output, and a temperature controller is provided for switching the heating device on and off. The temperature controller has fixed switching temperatures. For example, the temperature controller can have a lower switching temperature of 150°C and an upper switching temperature of 250°C. The specific switching temperatures depend on the intended use of the cleaning device. In the case of steam cleaning, they are naturally higher than in the case of cleaning with hot water.
[0023] Such a cleaning device has a particularly simple and cost-effective design.
[0024] A particularly simple and cost-effective design for the temperature controller is achieved by using a bimetallic switch. Alternatively, the temperature controller could also be implemented using a temperature sensor combined with a microcontroller in the control unit.
[0025] In a further development, the cleaning device features an output unit for providing information to the device operator. The output unit can be designed, for example, as a display unit with one or more warning lights or as an acoustic device that generates, for example, a buzzing or beeping sound.
[0026] The information provided to the device operator may indicate reduced cleaning performance or a request to descale the cleaning device. It may also be a request to adjust the pump output. If the heating system is configured as a steam generator, it may also indicate that an increased amount of residual water is to be expected, which could pose a risk to water-sensitive floors such as wooden parquet. It may also be a request to stop the device due to a critical lime content in order to prevent danger to the device operator or damage to the cleaning device.
[0027] Alternatively or in addition to the output of the information, a control circuit for carrying out automatic descaling of the cleaning device could also be provided in the control unit.
[0028] The cleaning device can advantageously have a controllable and, if necessary, adjustable pump for transporting the liquid, whereby the pump can be operated with different pump outputs so that the pump output can be varied or adjusted in steps by selecting between different fixed pump outputs. A reference curve of the electrical power consumption of the heating device or a value proportional to it is then stored in the control unit for each of the different pump outputs. In the case of continuously adjustable pump output with variable pump output, e.g. by means of a rotary potentiometer, an infinite number of reference curves would have to be stored. For an economical design of the cleaning device, a plurality of reference curves can then be stored, whereby each reference curve is assigned to a certain power range of the pump.
[0029] The cleaning device can be designed, for example, as a steam cleaning device or as a floor cleaning device, and the cleaning element can be a textile mop. The invention also relates to a method for operating a cleaning device as described above.
[0030] In the method for operating a cleaning device, the electrical power consumption of the heating device or a variable proportional thereto is recorded in a measuring mode in a first step by the device for determining the electrical power consumption of the heating device or a variable proportional thereto. In a next step, the recorded value is compared with a reference curve stored in the control unit to determine the degree of calcification of the heating device. These two steps are repeated continuously or at least at certain intervals. Depending on the result of the comparison, information is output to the device operator in an output unit, e.g. visually, haptically and / or acoustically. The output can be either a one-off - e.g. a short buzzing - or continuously - e.g. a permanent display of a warning.If the condition for outputting the information is no longer met after a new measurement mode (acquisition and comparison), the output of the information can be stopped.
[0031] In an embodiment of the method for operating a cleaning device, the reference curve can have at least one limit value, the passing of which causes the output of information by an output unit.
[0032] "Passing" means exceeding or falling below a limit, depending on the type of reference curve. If the reference curve maps activation times, as explained below, then falling below a limit generally results in the output of information to the device operator.
[0033] Alternatively, or in addition to the information output, an automatic descaling process for the cleaning device could also be initiated. Various thresholds are possible, as already explained above: a warning that the cleaning performance is already impaired, a request to descale or adjust the pump performance, or a request to stop the device. The information can be output as the calcification level increases.
[0034] In one possible embodiment of the method for operating a cleaning device, the device for determining the activation time of the heating device within at least one switching cycle of the heating device is recorded. A switching cycle is defined as "on" to "on" again, i.e., from the start of the heating device being energized to the next start of the energization. In particular, the relative activation time can also be determined, i.e., the relative time proportion of activation within at least one switching cycle. If the evaluation is carried out over several switching cycles, fluctuations between individual switching cycles can be filtered out.
[0035] In this embodiment, at least one reference curve represents activation times with increasing calcification of the heating device over time.
[0036] In a further development of the method for operating a cleaning device, the type of surface to be cleaned is determined in a preceding process step, e.g. by input from the device operator or by detection of the cleaning device itself, e.g. by means of sensors and / or evaluation electronics. In this way, different types of surfaces to be cleaned, such as stone surfaces, wooden surfaces, textile surfaces, plastic surfaces, etc., can be differentiated. The reference curves then have type-specific limit values, e.g. in the case of the heating device being designed as a steam generator, a special limit value for the cleaning of wooden surfaces, which warns against excessive water ingress due to calcification. In a further development of the method for operating a cleaning device, after information has been output to the device operator, the acknowledgement of the information by the device operator can be confirmed by actuating a switching element (e.g.Reset button) and the information output will then stop.
[0037] In order to avoid unnecessary information being given to the device operator, the electrical power consumption of the heating device or a variable proportional to it can be continuously recorded or the comparison with a reference curve stored in the control unit can only take place after a start-up time. The start-up time can be fixed or determined by the control unit. The degree of calcification should only be determined when the processes in the cleaning device and the temperatures have stabilized. The start-up time is taken into account when the cleaning device is switched on and when the pump output is changed. A fixed start-up time can be implemented in an electronic circuit in the control unit, for example by means of a delay element. If determined by the control unit, the start-up time can be considered to have ended when the determined values no longer fluctuate but have stabilized.
[0038] In a possible further development of the method for operating a cleaning device, a calibration is advantageously provided, which allows for consideration of properties of the heating device that deviate within the range of tolerances, which in turn can significantly increase the accuracy of the statement regarding the actual degree of calcification:
[0039] When the cleaning device is put into operation for the first time, the at least one reference curve stored in the control unit is calibrated, with the following steps: a) Determination of the electrical power consumption of the heating device or a variable proportional thereto b) Correction, i.e. shifting of the reference curve of the electrical power consumption of the heating device or the variable proportional thereto, so that the value of the initial determination corresponds to the stored initial value.
[0040] Steps a) and b) are carried out for all available power levels of a pump and all power-specific reference curves are corrected.
[0041] In a possible development of the method for operating a cleaning device, the activation time of the heating device within a switching cycle of the heating device is extended in one operating mode depending on the degree of calcification of the heating device. A correction factor can be provided for this purpose (t_corr or T_corr). In a first variant, the correction factor can be a time correction factor, namely a fixed time value (t_corr) which is applied from a certain degree of calcification, i.e. from a certain value of the electrical power consumption of the heating device or the variable proportional thereto, e.g. 5 seconds for a low degree of calcification, 10 seconds for a medium degree of calcification and 15 seconds for a high degree of calcification. It is also possible to implement an individually calculated correction factor.
[0042] An alternative correction factor T_corr could change the upper switching temperature of the temperature-controlled heater and increase it with increasing degree of calcification, e.g. 5 °C for a low, 10 °C for a medium and 15 °C for a high degree of calcification.
[0043] In terms of circuitry, the correction factor can be determined or calculated by a microcontroller depending on a specific degree of calcification, i.e., starting from a specific value of the electrical power consumption of the heating device or a variable proportional to it. This development advantageously ensures that the heating and, if necessary, evaporation of the liquid is carried out comprehensively despite the increasing degree of calcification, and that liquid with too low a temperature or steam with a high residual liquid content is not generated.
[0044] If the cleaning device is to be used again in measurement mode, i.e., if the degree of calcification is to be determined again, the application of the correction factor t_corr or T_corr is suppressed for the duration of the determination of the electrical power consumption of the heating device or the variable proportional to it. The determination of the electrical power consumption of the heating device or the variable proportional to it is thus not distorted by the correction factor t_corr or T_corr.
[0045] In a possible further development of the method for operating a cleaning device, the activation time t initial of the heating device, which can also be referred to as the preheating time, is extended by a correction factor t_corr after the cleaning device has been switched on, depending on the degree of calcification of the heating device, i.e. it is adjusted depending on the recorded value of the electrical power consumption of the heating device or a variable proportional thereto. So that the control unit can make such an adjustment of the activation time, the value of the degree of calcification recorded during the last operation of the cleaning device is stored in a memory. The correction factor t_corr can be the same value which - as previously explained - extends the activation time in operating mode. Alternatively, it can be another value stored in the control unit or calculated by a microcontroller of the control system.
[0046] In contrast to the fixed preheating time known from the prior art, by incorporating a correction factor dependent on the degree of calcification, it can be ensured that a pump of the cleaning device is only switched on when the temperature is sufficient despite the presence of calcification in the heating device. This is particularly relevant if the heating device has a steam generator and liquid is being evaporated.
[0047] The described invention and the described advantageous developments of the invention also represent advantageous developments of the invention in combination with one another - insofar as this is technically reasonable.
[0048] With regard to further advantages and advantageous embodiments of the invention in terms of construction and functionality, reference is made to the dependent claims and the description of embodiments with reference to the accompanying figures.
[0049] Example
[0050] The invention will be explained in more detail with reference to the attached figures.
[0051] It shows
[0052] Fig. 1 shows the functional elements of the cleaning device
[0053] Fig. 2 an electrical replacement diagram of the cleaning device
[0054] Fig. 3a and b Representations of the activation times (on-time) of the heating device in new and calcified condition
[0055] Fig. 3c Representation of the activation time taking into account a correction factor
[0056] Fig. 4a a reference curve stored in the control unit with three limit values
[0057] Fig. 4b the calibration process by shifting a reference curve Fig. 4c different reference curves, where a respective
[0058] Reference curve is assigned to a specific pump performance
[0059] Fig. 5 Representation of the activation time after switching on the
[0060] Cleaning device taking into account a correction factor shows a representation of the functional elements of the cleaning device 10.
[0061] In the cleaning device 10, liquid 100 is transported from a liquid container 1 to a heating device 2, where the liquid is heated to form steam 101. The steam 101 is applied to a cleaning element 8, which can be embodied as a textile mop pad. The cleaning of a surface 1000 to be cleaned is achieved by relative movement of the cleaning element 8 over the surface to be cleaned.
[0062] A control unit 3 is provided for controlling the cleaning device 10. The control unit 3 can be connected to or have an output unit 3.1 for outputting information to a machine operator. Furthermore, it can have input units such as electrical switches.
[0063] The heating device 2 is electrically operated (power source 5 not shown here). The heating device 2, with its heating element 2.1, is temperature-controlled and maintains a fixed or predetermined temperature range. A temperature controller 4, which has fixed switching temperatures in this case, is provided for switching on and off, i.e., temporarily applying current. In the example shown, the temperature controller is designed as a bimetallic switch.
[0064] The heat transfer from the heating device 2 to the liquid 100 takes place on the surface of the heating element 2 that is in contact with the liquid. As shown in the figure, the surface is already covered with a layer of lime 20, which impairs the heat transfer. shows an electrical equivalent diagram of the cleaning device 10.
[0065] Heating element 2.1 is connected to a power source 5 and can thus be supplied with electrical current. For clocked activation of the
[0066] A temperature controller 4 is provided for the heating element 2.1, which ensures that the heating device 2 maintains a predetermined or fixed temperature. To protect the heating element 2.1, an optional electrical fuse 6 is also provided in the illustrated embodiment. A hydraulic pump 7, which is also connected to a power source 5, is provided to transport the fluid 100. The pumping power of the hydraulic pump 7 can be adjusted, either continuously or by selecting different power levels.
[0067] The control unit 3 (not shown) has a device for determining the electrical energy consumption (E) of the heating device 2 or a variable proportional thereto (ROT) and at least one reference curve R stored in the control unit 3.
[0068] The determination device continuously records the electrical power consumption (E) of the heating device 2 or a variable proportional thereto (ROT). In a next step, a comparison is made with a reference curve (R) stored in the control unit 3 to determine the degree of calcification of the heating device 2. Tests were carried out in advance during production to establish the reference curves. The values of the electrical power consumption (E) of the heating device 2 or the variable proportional thereto (ROT) corresponding to a specific critical degree of calcification are thus known. Depending on the result of the comparison, information is output to the device operator via the output unit 3.1.
[0069] Fig 3a and b show representations of the activation times (On-Time) of the
[0070] Heating device 2 in a) new and b) calcified state. For this purpose, the activation times of the heating device are plotted against time, as recorded by the device for determining the electrical energy consumption (E) of the heating device 2 or the variable proportional thereto (ROT). One switching cycle of the heating device extends to the sum of the activation time t_on and the time t_off during which the heating device 2 is not activated. It can be seen that the activation time t_on of the heating device 2 and thus the period of energy consumption E decreases with increasing calcification, i.e. t_on becomes smaller. This can also be expressed as the relative activation time decreasing, i.e. t_on / (t_on+t_off) becomes smaller. This variable is referred to as ROT, relative on-time, in the figures described below.
[0071] Fig. 3c shows the activation time t_on taking into account a correction factor t_corr.
[0072] If the heating and, if applicable, evaporation of the liquid 100 is to be carried out comprehensively despite the increasing degree of calcification, and if liquid 100 with an excessively low temperature or vapor 101 with a high residual liquid content is not to be generated, the activation time t_on of the heating device 2 within a switching cycle of the heating device 2 can be extended depending on the degree of calcification of the heating device 2 in the operating mode of the cleaning device 10 shown here. A correction factor t_corr is provided for this purpose. The duration of the electrical energy consumption E in a respective switching cycle is thus extended.
[0073] Fig. 4a shows a reference curve R stored in the control unit 3 with three defined limit values G1, G2, G3. At a first time t1, a first limit value G1 is reached or passed, at a second time t2 a second limit value G2, and at a third time t3 a third limit value G3. Upon passing the respective limit values G1, G2, G3, the control unit 3 outputs information to the device operator via the output unit 3.1. For the possible configuration and output of the information, please refer to the above explanations.
[0074] The reference curve is shown here and in the figures described below as a linearly declining straight line. This representation was chosen for simplification. Curves resulting from tests and measurements usually deviate from this and exhibit a wide variety of curvatures. shows the calibration process by shifting a
[0075] Reference curve R.
[0076] When the cleaning device 2 is put into operation, at time tO the at least one reference curve R stored in the control unit 3 is calibrated, with the following steps: a) Determination of the variable (ROT) proportional to the electrical power consumption (E) of the heating device 2 b) Correction of the reference curve R by correcting it, i.e. shifting it, so that its start value matches the value determined in a) at time tO. If the determined value is higher, for example, and is around 90% as in the example shown, the reference curve R0 is shifted upwards (see arrow) so that its value for tO is raised from around 75% to around 90%. The calibrated reference curve is labeled Real in the figure.
[0077] 4c shows, by way of example, roughly schematically different reference curves, wherein a respective reference curve is assigned to a specific pump output of a hydraulic pump 7 of the cleaning device 10, i.e. a first
[0078] Reference curve R1 for a first pump output, a second reference curve R2 for a second pump output, and a third reference curve R3 for a third pump output. The reference curves are therefore pump output-specific and are selected according to the prevailing pump output.
[0079] Fig. 5 shows a representation of the activation time t_on after switching on the cleaning device 10 at time tO taking into account a correction factor t_corr.
[0080] To ensure sufficiently long preheating of the heating device 2 before activating the pump 7 of the cleaning device 10 at the activation time t_P, the activation time t_initial of the heating device 2 can be extended by a correction value t_corr after the cleaning device 10 is switched on, depending on the degree of calcification of the heating device 2. The duration of the electrical energy consumption E during preheating is thus extended.
[0081] List of reference symbols
[0082] 1 liquid container
[0083] 2 heating device (e.g. boiler)
[0084] 2.1 Heating element
[0085] 3 Control unit
[0086] 3.1 Output unit
[0087] 4 temperature controllers (e.g. temperature switches)
[0088] 5 Power source
[0089] 6 electrical fuse
[0090] 7 Pump
[0091] 8 Cleaning element (e.g. wiping pad)
[0092] 10 Cleaning device
[0093] 20 lime layer
[0094] 100 liquid (e.g. water)
[0095] 101 Steam (e.g. water vapor)
[0096] 1000 area to be cleaned (e.g. floor of a room)
[0097] E Electrical energy consumption t_on Period in which the heating device is activated (on) t_off Period in which the heating device is not activated (off) t nitial Preheating phase t_P Switch-on time of the pump tO Activation time t1 First time at which a first limit value G1 is reached t2 Second time at which a second limit value G2 is reached t3 Third time at which a third limit value G3 is reached R Reference curve
[0098] RO uncalibrated reference curve
[0099] Real calibrated reference curve
[0100] R1 pump performance-specific reference curve of a first pump performance R2 pump performance-specific reference curve of a second pump performance
[0101] R3 pump performance specific reference curve of a third pump performance ROT Relative activation time of the heating device
Claims
Claims 1. Cleaning device (10) with a cleaning element (8), a liquid container (1), a current-operated temperature-controlled heating device (2), in particular with a steam generator, for heating a liquid (100) and with a control unit (3) for controlling the cleaning device (10), characterized in that the control unit (3) has a device for determining the electrical power consumption (E) of the heating device or a variable proportional thereto (ROT) and at least one reference curve (R) stored in the control unit (3).
2. Cleaning device according to claim 1, characterized in that the heating device (2) can be operated with a constant heating power and a temperature controller (4) is provided for switching the heating device (2), wherein the temperature controller (4) has fixed switching temperatures, and that the temperature controller (4) is designed in particular as a bimetal switch.
3. Cleaning device according to one of the preceding claims, characterized in that the cleaning device (10) has an output unit (3.1) for outputting information to the device operator.
4. Cleaning device according to one of the preceding claims, characterized in that the cleaning device (10) has a controllable pump (7) for Transport of the liquid (100), that the pump (7) can be operated with different pump power and that in the control unit (3) for each of the different pump powers a reference curve (R1, R2, R3) of the electrical power consumption (E) of the heating device or a variable proportional thereto (ROT) is stored.
5. Method for operating a cleaning device (10) according to one of the preceding claims, characterized in that in a measuring mode by the device for determining the electrical power consumption (E) of the heating device (2) or a variable proportional thereto (ROT) a detection is carried out that a comparison is carried out with a reference curve (R) stored in the control unit (3) to determine the degree of calcification of the heating device (2) and that depending on the result of the comparison an output of information is made to the device operator.
6. Method for operating a cleaning device according to claim 5, characterized in that the reference curve (R) has at least one limit value (G1, G2, G3), the passing of which causes the output of information.
7. Method for operating a cleaning device according to one of claims 5 or 6, characterized in that the device for determining the activation time (t_on) of the heating device (2) within at least one switching cycle of the heating device (2) is detected, and the reference curve (R) activation times (ROT) with increasing Degree of calcification of the heating device (2) over time (t).
8. Method for operating a cleaning device according to claim 7, characterized in that in a preceding method step the type of surface to be cleaned is determined and that the reference curves (R) have type-specific limit values (G1, G2, G3).
9. Method for operating a cleaning device according to claim 7 or 8, characterized in that the acknowledgement of the information by the device operator can be confirmed by actuating a switching element and the information output is then terminated.
10. Method for operating a cleaning device according to one of claims 5 - 9, characterized in that the detection of the electrical power consumption (E) of the heating device (2) or a variable proportional thereto (ROT) or the comparison with a reference curve (R) stored in the control unit (3) only takes place after a start-up time. 11 . Method for operating a cleaning device according to one of claims 5 - 10, characterized in that when the cleaning device (2) is put into operation, a calibration of the at least one reference curve (R) stored in the control unit (3) is carried out, with the following steps: a) Determination of the electrical power consumption (E) of the Heating device (2) or a variable proportional thereto (ROT) b) Correction of the reference curve (R) of the electrical power consumption of the heating device or a variable proportional thereto.
12. Method for operating a cleaning device according to one of claims 5 - 11, characterized in that in an operating mode the activation time (t_on) of the heating device (2) within a switching cycle of the heating device (2) is extended by a correction factor (t_corr) depending on the degree of calcification of the heating device (2).
13. Method for operating a cleaning device according to one of claims 5 - 12, characterized in that the activation time (t_in itial) of the heating device (2) after switching on the cleaning device (10) is extended by a correction factor (t_corr) depending on the degree of calcification of the heating device (2).