Cooking appliance and method for controlling a cooking appliance

Abstract

Cooking appliance (10) with a control unit (18), a stagnation flushing module (20) which can request a stagnation flush depending on external information, and a hand shower (16).

Description

[0001] The invention relates to a cooking appliance with a hand shower and a method for controlling such a cooking appliance.

[0002] Cooking appliances with handheld shower heads are well known. The handheld shower head, located on or near the cooking appliance, is designed to provide drinking water for preparing dishes such as soups or sauces.

[0003] During normal use of a cooking appliance, all water pipes are regularly flushed to ensure that no stale water remains in the pipes. However, if the hand shower is used very infrequently, for example, every two months, pathogenic bacteria, such as Legionella, can multiply in the water pipes of the hand shower. If this stale water from the hand shower is then used, there is a risk of contaminating the surfaces of the cooking appliance and food. Furthermore, water vapor, which is generated, for example, during use of the cooking appliance, can be inhaled by the user and endanger their health.

[0004] DE 37 22 282 C2 shows a device for heat-treating food using steam.

[0005] Furthermore, DE 10 2014 104 395 A1 shows a sanitary fitting.

[0006] A hand shower holder for a cooking appliance is known from DE 20 2008 005 302 U1.

[0007] Furthermore, EP 1 473 521 A1 discloses a cooking appliance with a spray device for cleaning the cooking chamber.

[0008] EP 2 439 174 A1 discloses a flow device for Legionnaires' disease disinfection of branch lines and terminal devices of water systems.

[0009] EP 2 500 475 A2 shows a device for automatically flushing pipes.

[0010] The object of the invention is to prevent pathogenic germs from multiplying in the piping system.

[0011] To achieve this objective, a cooking appliance is provided comprising a controller, a stagnation flush module that can request a stagnation flush based on external information, and a hand shower. For the purposes of the invention, a stagnation flush is understood to mean flushing a water pipe in which a sufficiently large quantity of water flows through the water pipe within a short period of time, for example 2 liters within one minute, to ensure essentially complete water exchange in the water pipe. The stagnation flush module, taking into account external information relevant to germ formation in the water pipe, ensures that a stagnation flush is requested when a specific risk threshold is exceeded. This needs-based and efficient cleaning of the water pipe of the hand shower prevents any danger posed by stagnant water.

[0012] The risk threshold can be predefined at the factory, or a variable risk threshold can be determined depending on the operating conditions of the cooking appliance.

[0013] Preferably, a temperature sensor is provided which is coupled to the stagnation flush module. The temperature sensor determines in particular the temperature of the water in the water pipe, since temperature is a key factor in germ formation. The temperature of the water can be determined either directly in the water pipe or, alternatively, indirectly by installing the temperature sensor at a suitable location outside the water pipe. The temperature of the water in the water pipe is then deduced from the measured ambient temperature. By taking the temperature into account, for example, at lower ambient temperatures of the cooking appliance, a stagnation flush can be requested less frequently than would, ceteris paribus, be necessary at higher ambient temperatures. This increases user-friendliness and reduces water consumption.

[0014] According to an advantageous embodiment, a sensor is provided that detects the water flow rate of the hand shower and is coupled to the stagnation flush module. This sensor provides the stagnation flush module with information on the water flow rate of the hand shower, including information such as the time of last use and the amount of water drawn per unit of time. This information can be taken into account by the stagnation flush module when determining a current risk value and thus when requesting a stagnation flush, since the time and the amount of water flowing through the hand shower are key factors influencing the quality of the water in the water supply.For example, the flow rate of a quantity of water that is drawn in several small amounts over a certain period of time may be assessed less favorably than the same quantity of water that flows through the hand shower all at once, because a flow rate of several small amounts is less likely to ensure complete water exchange in the water pipe than a large amount of water in a short period of time. The most important advantage, however, is that the sensor can take into account the idle times of the hand shower. This means that after a long period in which the hand shower has not been used and there is therefore a particularly high risk of heavily contaminated water in the water pipe, a stagnation flush can be requested. Taking the water flow rate into account thus enables needs-based stagnation flushing, which ensures high water quality and can simultaneously reduce water consumption for stagnation flushing.

[0015] One embodiment of a cooking appliance according to the invention has a door. This cooking appliance is particularly suitable for professional use in kitchens, restaurants, and large-scale catering, known as a combi steamer, which can be used to cook food using hot air, steam, or a combination of hot air and steam.

[0016] In an alternative embodiment of a cooking appliance according to the invention, it has a cooking pan with a heating surface at the bottom, which can be closed with a lid. In this case, too, the cooking appliance is particularly suitable for professional use in kitchens, restaurants, and large-scale catering.

[0017] According to the invention, to achieve the above-mentioned object, a method for controlling a cooking appliance is also provided, in which a control system indicates to a user, depending on usage parameters, that a stagnation flush should be performed. In this way, the user is informed at the time at which a stagnation flush appears advisable based on the usage parameters taken into account. This notification can be communicated, for example, by a display panel, the illumination of a warning light, or via an acoustic signal. The usage parameters include, in particular, the water flow rate of the hand shower over the past few days and the ambient temperature of the cooking appliance. This achieves a high level of user-friendliness and prevents any unintentional hazard caused by stagnant water.

[0018] Preferably, the cooking appliance will be locked if the user fails to perform the stagnation flush. The lock will only be released once a user has performed the requested stagnation flush. This allows a stagnation flush to be forced if the control system deems it necessary.

[0019] It is advantageous if a stagnation flush module evaluates the usage pattern of a hand shower. This enables individualized, user-tailored stagnation protection. For example, if the hand shower is used regularly but infrequently, a stagnation flush is requested early to prevent the water in the pipe from posing a particularly high health risk the next time it is used, which, based on the usage pattern information, occurs well after a time when a stagnation flush would be necessary.

[0020] The control system can also implement a forecast function that allows a stagnation flush to be requested preventively. For example, a stagnation flush can be requested in the morning when the device is switched on, even though a predefined risk threshold has not yet been reached, but the control system can detect that the risk threshold will be exceeded over the course of the day. This prevents a stagnation flush from having to be performed during ongoing operation.

[0021] In a preferred embodiment, information about the water quality is provided to the stagnation flush module. The information about the quality of the water supplied to the hand shower's water line can be obtained, for example, through measurements or can be permanently entered, for example, when setting up the cooking appliance and / or during maintenance work. The water quality of the supplied water is a key factor that determines how quickly the water quality in the water line reaches a critical level, thus necessitating a stagnation flush. By taking water quality into account, the risk of a stagnation flush being requested too late is reduced and any danger to the user is further reduced.

[0022] Alternatively, the water quality in the hand shower's water line can be determined by suitable devices, especially automatically, and taken into account by the stagnation module. This minimizes the risk of stagnant water, as the water quality of the water in the water line is directly determined, thus enabling timely stagnation flushing.

[0023] In another preferred embodiment, the hand shower is blocked when the temperature in a cooking chamber exceeds certain values. A temperature of 50°C, for example, is such a limit, since at this temperature a large portion of the water introduced into the cooking chamber evaporates. By preventing the hand shower from being used above a certain temperature in the cooking chamber, it is ensured that water from the hand shower's water line cannot enter the hot cooking chamber, thus preventing the resulting steam from endangering the user's respiratory tract and mucous membranes.

[0024] The process may stipulate that certain cooking programs are only released after a stagnation rinse once the cooking chamber has been heated to at least a specified temperature for a specified time. Heating the cooking chamber, for example, for 2 minutes at a minimum of 90 °C, ensures that the majority of pathogenic germs that may have been introduced into the cooking chamber by the stagnation rinse are killed. This prevents these germs from multiplying rapidly and posing a health risk during low-temperature cooking programs, such as the "Proving" cooking program at a temperature of approximately 30 °C.

[0025] Further advantages and features are evident from the following description in conjunction with the attached single drawing. This shows: - Fig. 1 shows a schematic view of a cooking appliance according to the invention.

[0026] In Fig.1 shows a cooking appliance 10 according to the invention with a housing 12 which has a cooking chamber 14, a hand shower 16 as well as a control 18 and a stagnation flushing module 20.

[0027] The cooking chamber 14 is closed by a door 22, which can be opened and closed by means of a handle 24 attached to the door 22.

[0028] In contrast to the type of cooking appliance shown, the hand shower can also be attached to a cooking appliance that has a cooking pan that can be closed with a lid.

[0029] The hand shower 16 is connected to the cooking appliance 10 by a hose 32. The hose 32 can be accommodated in the cooking appliance 10 by means of a hose reel (not shown) and can be automatically wound up by the latter.

[0030] The connections for the hand shower 16 inside the cooking appliance, the hose 32, and the hand shower 16 form a water line 34 through which water is directed to the hand shower 16. The water flow can be controlled by a lever 36 located on the hand shower 16.

[0031] Next to the door 22, a display surface 38 is arranged in the housing 12, which is provided as an interface between the controller 18 and a user and is configured as an input and output device.

[0032] The display surface 38 is preferably a touchscreen.

[0033] The stagnation flush module 20 is configured to monitor the water line 34 and request a stagnation flush when needed. For this purpose, the cooking appliance 10 comprises a sensor 40, which is arranged on the water line 34 and detects the water flow rate of the hand shower 16, as well as a temperature sensor 42, which is arranged on the housing 12 and determines the temperature of the surroundings of the cooking appliance 10. The sensor 40 and the temperature sensor 42 are each coupled to the stagnation flush module 20 and provide it with information.

[0034] The temperature sensor 42 may alternatively be arranged on the water line 34 to determine the temperature of the water in the water line 34.

[0035] The stagnation flushing module 20 can additionally be configured to monitor additional water-carrying lines of the cooking appliance 10 and to request corresponding stagnation flushes.

[0036] During operation of the cooking appliance 10, the stagnation flush module 20 monitors the condition of the water line 34 and, depending on external information, requests a stagnation flush of the water line 34 if necessary in order to prevent the user from being endangered by stale water from the water line 34.

[0037] For the purposes of the invention, the operation of the cooking appliance 10 is understood to mean that the cooking appliance 10 is connected and supplied with energy, regardless of whether the cooking appliance 10 is used to prepare food or not.

[0038] Furthermore, the stagnation flush module 20 also monitors the water line 34 when the cooking appliance 10 is switched off and / or not supplied with external power, since these times are also important for ensuring sufficiently high water quality in the water lines 34 of the cooking appliance 10. The stagnation flush module 20 is powered by an internal energy source, such as a buffer battery, which is provided to bridge the times without an external power supply.

[0039] To ensure protection against stagnant water, which is hazardous to health due to a potentially high concentration of pathogenic germs, the stagnation flush module 20 uses the information available to it to assess the current risk of hazards posed by the water in the water line 34. If the risk exceeds a certain risk threshold, the stagnation flush module 20 requests a stagnation flush by having the controller 18 indicate to the user, depending on usage parameters, that a stagnation flush should be performed.

[0040] This indication to the user that a stagnation flush should be performed can be displayed on the display surface 38. Alternatively or additionally, this indication can include the illumination of a warning lamp 44 and / or the emission of an audible signal.

[0041] When assessing the risk, the water flow rate of the hand shower 16, in particular the time since the last use of the hand shower 16, the usage pattern of the hand shower 16, information on the water quality as well as the outside temperature and / or the temperature of the water pipe 34, which are provided to the stagnation flush module 20 for this purpose, are taken into account.

[0042] The cooking appliance 10 can be locked by the control unit 18 if a stagnation flush is detected as necessary and can only be unlocked again after a user has performed the stagnation flush.

[0043] The locking of the cooking appliance 10 may involve blocking the cooking programs so that they cannot be executed, or may involve locking the door 22 so that it cannot be opened.

[0044] Whether a stagnation flush is required is checked and requested, particularly when the cooking appliance 10 is switched on. The typical usage period of the cooking appliance 10 is preferably taken into account. This means that a stagnation flush is requested even if it is not currently required, but it is expected that a risk threshold will be exceeded within the current usage period. This prevents a stagnation flush from being requested while the cooking appliance 10 is in use. This is particularly important if the cooking appliance 10 is to be locked until a stagnation flush has been performed.

[0045] Alternatively, the locking of the cooking appliance 10 can be prevented during use and only take place afterwards.

[0046] To perform the stagnation flush, the user must draw a specified amount of water within a specific time via the hand shower 16. To do so, the user operates the lever 36 on the hand shower 16 and drains the water, for example, via a drain or into a container.

[0047] Alternatively, the cooking appliance 10 may have a drain through which the water can be drained away.

[0048] The hand shower 16 can be blocked by the control 18 if the temperature in the cooking chamber 14 exceeds a certain value, in particular to prevent the stale water from the water line 34 from being introduced into the hot cooking chamber 14 and evaporating there.

[0049] After a stagnation rinse, the control system 18 can lock certain cooking programs and only release them again once the cooking chamber 14 has been heated above a predetermined temperature for a specified period of time in order to kill any pathogenic germs that may be present in the cooking chamber 14. The cooking programs that are locked after a stagnation rinse include, in particular, cooking programs with a temperature below 50°C, such as cooking programs for fermentation or keeping warm.

[0050] Stagnation rinsing can be performed not only on a cooking appliance of the type described above, i.e., a combi steamer. It can also be performed on any cooking appliance that has at least one cooking pan, the bottom of which has a heating device, and in which food can be prepared.

Claims

[1] Cooking appliance (10) with a control system (18), a stagnation flush module (20) which can request a stagnation flush depending on external information, and a hand shower (16). [2] Cooking appliance (10) according to claim 1, characterized by that a temperature sensor (42) is provided which is coupled to the stagnation flushing module (20). [3] Cooking appliance (10) according to one of the preceding claims, characterized by that a sensor (40) is provided which detects the water flow rate of the hand shower (16) and is coupled to the stagnation flush module (20). [4] Cooking appliance (10) according to one of the preceding claims, characterized by that the cooking appliance (10) has a cooking chamber (14) with a door (22). [5] Cooking appliance (10) according to one of claims 1 to 3, characterized by that the cooking appliance (10) has a cooking pan with a lid. [6] Cooking appliance (10) according to one of the preceding claims, characterized bythat the cooking appliance (10) has a cooking pan with a heating surface on the bottom. [7] Method for controlling a cooking appliance (10), in which a controller (18) indicates to a user, depending on usage parameters, that a stagnation rinse should be carried out. [8] Method according to claim 7, characterized by that the cooking appliance (10) is locked if the user does not carry out the stagnation flush. [9] Method according to claim 7 or 8, characterized by that a stagnation flush module (20) evaluates the usage pattern of a hand shower (16). [10] Method according to claim 9, characterized by that information about the water quality is provided to the stagnation flushing module (20). [11] Method according to one of claims 9 or 10 characterized by that the hand shower (16) is blocked if the temperature in a cooking chamber (14) exceeds certain values. [12] Method according to claim 11, characterized bythat certain cooking programs are only released after a stagnation rinse when the cooking chamber (14) has been heated to at least a predetermined temperature for a predetermined time.

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