Cooking appliance with a hand shower and method for reducing the number of germs

Abstract

Cooking appliance (1) with a hand shower (11) which can be connected to a drinking water supply system via a supply line (21), wherein, in the connected state, water can be dispensed via the hand shower (11) for rinsing a cooking chamber (3), for filling containers or for quenching cooking food via a hand shower head (13), and with an electronic device control, wherein a heating device (33) is integrated in the supply line (21), characterized by the fact that by means of the heating device (33), controlled by the device control, incoming water can be heated to a temperature of at least 65°C, thereby reducing the number of germs in the supply line (21) and the hand shower (11), and A hand shower holder (35) is provided for the controlled removal of the germ-contaminated water, which can be inserted into the cooking chamber (3) or a pan of the cooking appliance (1).

Description

[0001] The present invention relates to a cooking appliance and a method for controlling a cooking appliance.

[0002] More specifically, the present invention relates to a cooking appliance with a hand shower which is connected to a drinking water supply system via a supply line and through which water can be dispensed, depending on the user, for rinsing a cooking chamber, filling containers, or dousing food during cooking via a hand shower head. The cooking appliance is controlled by an electronic device control unit.

[0003] The term "cooking appliance" here refers to all appliances used for the treatment, in particular the cooking, of food and which have a hand shower, i.e., in particular combi steamers and crucible appliances.

[0004] Hand showers generally consist of a shower head with a valve to control the water flow and a shaft that supports the shower head. A supply line is attached to the shaft, which is connected to the drinking water supply line.

[0005] From DE 10 2008 024 552 A1, a cooking appliance designed as a steam cooker with a heat exchanger is known, in which the condensation heat of the steam cooker is made available to a heat consumer. In one embodiment, the heat consumer is formed by a hot water connection to the cooking appliance for use with a hand shower of the cooking appliance.

[0006] The usage of the hand shower can vary considerably, and extended periods of inactivity, up to several days, including weekends, can occur. Drinking water regulations stipulate that the water supplied to water connections must have a bacterial count below a certain threshold. However, this does not mean that the supplied water is sterile.

[0007] Examples of germs that may occur include Legionella and Pseudomonas aeruginosa.

[0008] The supply line for a hand shower of a cooking appliance runs from the house's drinking water connection to a hand shower head, which is grasped by the user and put into operation. This is done, for example, by pressing a valve button in the hand shower head, thereby controlling the water output.

[0009] The water supply line and the hand shower button are located near the cooking chamber of the appliance, which can reach temperatures of up to 300 °C, at least temporarily. These high temperatures also affect the interior walls of the cooking chamber, causing the adjacent technical compartment—which houses the appliance control unit, other components, and the water supply line for the hand shower—to heat up to a temperature of approximately 30 to 50 °C. If the stagnant water in the supply line is within this temperature range, it creates ideal conditions for bacterial growth.

[0010] Particularly detrimental is, for example, the practice of rinsing or "cooling" food, such as splattering pasta at the end of cooking in salted water to quench the salt water or rinse off adhering starch. If the pasta, which is in baskets and has just been lifted out of the salted water, is sprayed directly onto the food, germs will remain there. This should therefore be avoided.

[0011] The risk of contamination is particularly high when such cooking appliances are used in large hospital kitchens where food is provided to immunocompromised patients.

[0012] To achieve a reduction in health-endangering germs, DE 10 2016 108 724 A1 proposes a cooking appliance in which the supply line is flushed, i.e., the stagnant water in the supply line is flushed with fresh water from the drinking water supply.

[0013] However, the results are not yet entirely satisfactory. The fittings and valves of the supply line, as well as the design of the hand shower, create dead spaces that are not, or only poorly, flushed by the flowing fresh water, meaning that any germs present there cannot be, or can only be, effectively rinsed away. This, in turn, promotes the regeneration of germs when the water is stagnant.

[0014] Furthermore, the supply lines of such cooking appliances are usually flexible plastic hoses, with the plastic serving as a nutrient source for bacterial growth and proliferation. A biofilm of bacteria forms on the inner wall of the plastic hose, which can only be partially removed even by rinsing.

[0015] Integrating chemical disinfection of the tubing system into the devices is technically extremely complex and its effectiveness is limited, as disinfectants cannot reliably reach the dead spaces in the water-carrying tubing of the supply line. The same applies to the effectiveness of disinfectants against established biofilm buildup.

[0016] The object of the present invention is therefore to propose a cooking device that enables a cost-effective and energy-saving reduction of the number of germs in the hand shower and its fresh water supply line.

[0017] Furthermore, it is an object of the present invention to propose a method for reducing the number of germs in a hand shower of a cooking appliance and its fresh water supply line, which enables a cost-effective and energy-saving reduction of the number of germs.

[0018] The aim is not necessarily to completely eliminate the germs, but to reduce them, thereby restoring drinking water quality as much as possible.

[0019] The problems are solved by the subject matter of claims 1 and 9. Preferred embodiments are the subject matter of the dependent claims.

[0020] In a cooking appliance according to the invention, a heating element is integrated into the supply line by means of which, controlled by the appliance's control unit, the incoming water can be heated to a temperature of at least 65 °C, preferably at least 70 °C, thereby reducing the number of germs present in the supply line and the hand shower. A hand shower holder is provided for the controlled discharge of the germ-contaminated water; this holder can be inserted into the cooking chamber or a container of the cooking appliance.

[0021] This measure makes it possible to render relevant germs, namely Legionella and Pseudomonas aeruginosa, harmless.

[0022] Furthermore, it is advantageous if the heating system is designed as an instantaneous water heater. Instantaneous water heaters are cost-effective components and generally present no installation difficulties. They can be either electrically or gas-powered.

[0023] Microwave or inductive heating is also possible. In one embodiment, the supply line is at least partially made of metal and is routed at least partially along the outside of the cooking chamber or even inside the cooking chamber, so that this section heats the water when the cooking chamber is heated.

[0024] A particular advantage is that the flow rate or volumetric flow in the supply line is reduced when the heating element is active, especially if the heating element is an electric instantaneous water heater. Due to the smaller or significantly smaller flow rate, the energy input to the heating element can be considerably reduced, thus also reducing or preventing increased power consumption of the cooking appliance. Without a reduction in flow rate, a gas-fired instantaneous water heater is preferably used.

[0025] Advantageously, the heating element is located primarily at the inlet of the supply line, i.e., adjacent to the drinking water connection. This allows for a reduction in the number of germs across essentially the entire length of the supply line.

[0026] Advantageously, the feed line is a flexible hose and the cooking appliance has an automatic hose rewind device, a hose reel or a hose retraction spring, which allows the extended hose to be moved back into the cooking appliance.

[0027] Furthermore, it is advantageous that the heating device heats the incoming water to a temperature of 70 °C to 100 °C, preferably 80 °C to 90 °C. In particular, the water is heated to such a temperature that it reaches at least 70 °C at the outlet. According to the Drinking Water Ordinance (e.g., DVGW Worksheet W551), an exposure time of 3 minutes at a water temperature of 70 °C is sufficient for the treatment of Legionella. The pathogenic bacterium Pseudomonas aeruginosa is killed at temperatures as low as 55 °C. At higher temperatures, the germs are killed more quickly.

[0028] The hand shower holder allows the user to press the button on the hand shower and control the water flow. It can also be used to reduce the flow rate. The hand shower holder prevents the user from having to hold the hot hand shower and risking burns.

[0029] Advantageously, a temperature sensor is integrated into the hand shower holder to detect the temperature of the water dispensed by the shower head. This temperature is transmitted to the device's control unit, which determines when the required temperature is reached in the flowing heated water, thus enabling the start of the germ reduction process. Based on the detected temperature, the control unit can then determine the treatment duration. At the end of the time interval, the control unit can issue a corresponding signal, such as an audible signal, to the operator and / or display a message, informing the operator that the treatment is complete and the hand shower can be removed from its holder. The core temperature probe of a cooking appliance, for example, can be used as the temperature sensor.

[0030] Alternatively, a solenoid valve can be used to start and stop the water flow. This solenoid valve can be controlled by the device's control unit, thus automating the process.

[0031] Furthermore, it is advantageous that a sensor is provided to detect whether the hand shower is inserted into the hand shower holder. Only then does the device control initiate heating via the heating element. This prevents the user from touching the heating hand shower and potentially injuring themselves.

[0032] Advantageously, the device control unit features a clock module to monitor the time periods required to reduce the number of germs, signaling to the operator via a display on the cooking appliance that the treatment is to be carried out. After completion, this can be logged by the device control unit in its internal memory, thus documenting the germ treatment.

[0033] Furthermore, the electronic control unit can automatically and adaptively adjust the germ reduction intervals to the prevailing conditions and take into account the use of the hand shower. Typically, the temperature is measured on the control board of the cooking appliance to prevent overheating. This allows the temperature of the supply line, for example, the hose reel temperature, to be inferred. Alternatively, the temperature of the supply line can be inferred with sufficient accuracy from the cooking temperatures. Another alternative is the installation of one or more additional sensors in the supply line.

[0034] The present invention also includes a method for reducing the number of germs in a hand shower of a cooking appliance and its fresh water supply line. The method is characterized in that the incoming water is heated to at least 65 °C, preferably to at least 70 °C, thereby reducing the number of germs. A hand shower holder, which is inserted into the cooking chamber or a container of the cooking appliance, is provided for the controlled discharge of the germ-contaminated water.

[0035] Advantageously, the flow rate or volume flow of the heated water is significantly reduced, to one tenth to one fiftieth of the normal flow rate.

[0036] Furthermore, it is advantageous that the temperature of the heated water is determined by means of one or more - existing or additional - temperature sensors, and thereby the time from which a reduction in the number of germs occurs is determined.

[0037] Another advantage is that once the desired heating temperature is reached, the reduction of the number of germs takes place within a period of 10 seconds to 10 minutes. The higher the temperature, the faster the reduction of the number of germs.

[0038] If the temperature of the supply line is known, a table stored in the controller can be used to determine an average supply line temperature and a corresponding maximum service life. Alternatively, a formula can be stored in the device controller to calculate the maximum service life. Depending on the stored or calculated value, the controller then prompts the user to perform a microbial reduction.

[0039] The use of the hand shower can be registered by a corresponding sensor within the control unit and factored into the calculation of the timing for germ reduction, such that the intervals between germ reductions are increased when the hand shower is used. Furthermore, the device control unit can indicate to the operator that a potentially significant hygiene and health problem exists if the germ reduction according to the invention is not carried out.

[0040] Furthermore, it is advantageous that the functionality of the heating system can be checked using the existing or additional temperature sensor. If, within a predetermined time interval after the heating system is switched on by a corresponding signal from the device control, the temperature of the flowing water does not increase significantly, a failure of the heating system can be concluded.

[0041] To ensure that the germ reduction process is always safe for the operator, the invention proposes that a sensor, such as a reed contact and a magnet on the hand shower, detects the inserted hand shower in the hand shower holder and transmits this information to the device control, so that the heating device is only switched on when the hand shower has been inserted into the hand shower holder.

[0042] Furthermore, it is advantageous that an electronic device control system regularly prompts the operator to perform a germ count reduction. This prompt is achieved by the electronic device control system using a temperature measurement at the supply line and a table stored in the device control system that shows the increase in germ count in stagnant water as a function of temperature to determine the time for the germ count reduction.

[0043] Advantageously, the use of the hand shower is also taken into account when determining the time of germ reduction.

[0044] Further details, features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. These show: Fig. 1. A perspective view of a cooking appliance in the form of a combi steamer, with a corresponding hand shower; Fig. 2 another perspective view of the cooking appliance from Fig. 1 with the oven door removed; Fig. 3 a side view of the supply line and the hand shower, wherein the supply line is at least partially hose-like and wound onto a drum; Fig. 4 an embodiment of a hand shower head holder in sectional view; and Fig. 5 an alternative embodiment of the supply line without a hose reel system.

[0045] In the figures, identical elements are labelled with the same reference numbers.

[0046] In the Fig. 1 and Fig. Figure 2 shows a conventional cooking appliance 1 in the form of a combi steamer, which has a cooking chamber 3 that can be closed by a cooking chamber door 5. Next to the cooking chamber 3 is the so-called technical compartment 6, in which the drive mechanism for a fan wheel 7, the appliance control unit with display and operating panel 9, and a hand shower 11 with hand shower head 13 are located. A supply line 21 extends from the hand shower 11 to the rear of the cooking appliance 1, where, for example, the water connection for the drinking water supply is located behind the rear panel or below the base.

[0047] As can be seen, the hand shower head 13 is recessed in a niche-like recess 19 and pops up in the Fig. 1 and Fig. In the resting position shown in Figure 2, the hand shower head 13 does not protrude beyond the front of the cooking appliance. Due to the recessed design 19, the hand shower head 13 is easy to grasp and can be pulled out along with part of the supply line 21.

[0048] As further from Fig. As can be seen in Figure 2, the cooking chamber 3 has a drain 15 in the area of ​​its base 4, through which not only condensation and steam during cooking, but also water injected from the cooking chamber 3 by the hand shower 11 can be drained away.

[0049] As shown schematically, an internal temperature sensor 17 of the cooking appliance 1 is also located on the bottom 4 of the cooking chamber 3. This sensor serves as a core temperature probe during the corresponding cooking operation. This advantageously eliminates the need for an additional temperature sensor.

[0050] In Fig. Figure 3 shows an exemplary embodiment of the present invention. A supply line 21 is formed from a first essentially rigid line element 23, which may be made of metal or plastic, and which is connected to a connection element 25 and a connection 27 of the drinking water supply. The first line element 23 terminates in a hose winding device 29, where, similar to a garden hose, a second line element 31, formed from a flexible hose, is wound on a drum and is connected at its front end to a hand shower shaft 16 of the hand shower 11. The hand shower head 13 of the hand shower 11 has a push button 14, which, when pressed, can discharge a jet of water supplied by the supply line 21.

[0051] The supply line 21 thus forms a water level line in which the water only flows when the push button 14 is pressed.

[0052] To heat the flowing water and to reduce the number of germs in the supply line 21 and the hand shower 11, a heating device 33, preferably in the form of an instantaneous water heater, is arranged adjacent to the water connection 25.

[0053] In Fig. Figure 4 shows a hand shower holder 35 according to the invention, in which the hand shower head 13 is arranged.

[0054] The hand shower head 13 is held in a receiving chamber 36, which is dimensioned such that, according to dimension 37, the push button 14 of the hand shower head 13 is pressed when it is inserted. This means that when the hand shower head 13 is inserted into the hand shower holder 35, the valve of the hand shower head 13 opens and water flows out. The water outlet at the end of the hand shower 11 opposite the push button 14 is sealed in its receiving chamber by means of a gasket, and a relatively small channel 41 directs the water into an outlet chamber 43. The water simply flows out of this chamber. The hand shower holder 35, with the hand shower 11 inside, is then placed in the cooking chamber 3, so that the hot water is discharged via the cooking chamber drain 15. Now, the area of ​​the outlet bore of the hand shower holder 35 can be designed in such a way that a pipe can be attached to the outlet bore.is flanged in which the temperature sensor 17, for example the core temperature probe, is inserted so that the hot water flows around the probe.

[0055] Thus, the temperature sensor 17 is located opposite the outlet of channel 41, which significantly reduces the volume of the outgoing water, allowing the temperature sensor 17 to measure its temperature. The temperature sensor 17 is connected to the (not shown) device control unit and transmits the measured water temperatures to it.

[0056] In Fig.Figure 5 is an alternative embodiment of the present invention, shown only very schematically. The flexible second cable section 31 is not wound on a spool but is loose. For example, the second cable section 31 could be located outside the cooking appliance or in a drawer. The second cable section 31 is screwed to the heating element 33 by means of a screw element 51, and the first cable section 23, which has the connection element 25 and is relatively short, is screwed to the heating element 33 by means of a screw element 52.

[0057] The present invention thus provides a cooking appliance and a method by which a reduction in the number of germs in the supply line and the hand shower of a cooking appliance can be carried out and the goal can be achieved of restoring or even increasing the drinking water quality supplied by the drinking water supply after the germ reduction has been carried out at the hand shower head. Reference symbol list: 1 cooking appliance 3 Cooking chamber 4 Oven floor 5 Oven door 6 Technical Room 7 Fan wheel 9 Display and control panel 11 Hand shower 13 hand shower heads 14 snap fasteners 15 Oven drain 16 hand shower shafts 17 Temperature sensor (core temperature sensor) 19 niche-like recordings 21 Supply line 23 first conductor element 25 Connection element 27 Connection of the drinking water supply 29 Hose winding device 31 second conductor element 33 Heating system 35 Hand shower holder 36 Recording room 37 measure Channel 41 43 Exit room 51 Screw element 52 Screw element

Claims

[1] Cooking appliance (1) with a hand shower (11) which can be connected to a drinking water supply system via a supply line (21), wherein, in the connected state, water can be dispensed via the hand shower (11) for rinsing a cooking chamber (3), for filling containers or for quenching cooking food via a hand shower head (13), and with an electronic device control, wherein a heating device (33) is integrated in the supply line (21), characterized by , that by means of the heating device (33), controlled by the device control, incoming water can be heated to a temperature of at least 65°C, thereby reducing the number of germs in the supply line (21) and the hand shower (11), and A hand shower holder (35) is provided for the controlled removal of the germ-contaminated water, which can be inserted into the cooking chamber (3) or a pan of the cooking appliance (1). [2] Cooking appliance (1) according to claim 1, characterized by , that the heating device (33) is designed as an instantaneous water heater. [3] Cooking appliance (1) according to claim 1 or 2, characterized by , that when the heating device (33) is active, the volume flow in the supply line (21) is reduced compared to a normal volume flow. [4] Cooking appliance (1) according to any one of the preceding claims, characterized by , that the heating device (33) is essentially located at the inlet of the supply line (21). [5] Cooking appliance (1) according to any one of the preceding claims, characterized by that the feed line (21) is at least partially a flexible hose (31) and the cooking appliance (1) has an automatic hose winding device (29), hose reel or hose retraction spring. [6] Cooking appliance (1) according to any one of the preceding claims, characterized by , that the heating device (33) can heat incoming water to a temperature of 70°C to 100°C. [7] Cooking appliance (1) according to any one of the preceding claims, characterized by , that a temperature sensor (17) is provided in the area of ​​the hand shower holder (35) with which the temperature of the water dispensed by the hand shower head (13) can be determined. [8] Cooking appliance according to any of the preceding claims, characterized by , that a sensor is provided which detects whether the hand shower (11) is inserted into the hand shower holder (35). [9] Method for reducing the number of germs in a hand shower (11) and its fresh water supply line (21) of a cooking appliance (1), wherein the supply line (21) is connected to a drinking water supply system, characterized by , that Water flowing in is heated to at least 65°C by means of a heating device (33), thereby reducing the number of germs in the supply line (21) and the hand shower (11), and A hand shower holder (35) is provided for the controlled removal of the germ-contaminated water, which is inserted into a cooking chamber (3) or a pot of the cooking appliance (1). [10] Method according to claim 9, characterized by that the water is heated using an instantaneous water heater [11] Method according to claim 10, characterized by , that the volume flow of the heated water in the supply line (21) is significantly reduced compared to a normal volume flow. [12] Method according to claim 11, characterized by , that a reduction to 1 / 10 to 1 / 50 of the normal volume flow is carried out. [13] Method according to any one of claims 9 to 12, characterized by , that the temperature of the heated water is determined by means of one or more temperature sensors (17) and thereby the time from which a reduction in the number of germs occurs is determined. [14] Method according to claim 13, characterized by , that the functionality of the heating device (33) is checked by means of the temperature sensor(s). [15] Method according to any one of claims 9 to 14, characterized by , that the incoming water is heated to a temperature of 70°C to 100°C. [16] Method according to any one of claims 9 to 15, characterized by , that after reaching the desired heating temperature, the reduction process of the number of germs is carried out within a period of 10 seconds to 10 minutes. [17] Method according to any one of claims 9 to 16, characterized by that an electronic device control system regularly prompts the operator to perform a procedure according to one of claims 9 to 16. [18] Method according to claim 17, characterized by, that the electronic device control determines the time of execution of the method according to one of claims 9 to 16 by means of a temperature measurement at the supply line (21) and a table or formula stored in the device control which represents the increase in the number of germs in the stagnant water in supply line (21) and hand shower (11) as a function of the measured temperature. [19] Method according to one of claims 17 or 18, characterized by , that the use of the hand shower (11) is taken into account for determining the time of carrying out the procedure according to one of claims 9 to 16.

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