DE102021213621A1 - Household steamer and method of operating the same - Google Patents

Abstract

Household steam cooking appliance (15), having n ≥ 4 water-carrying components including a water supply (2), a mixing tank (5), an evaporator (4) and a pump (3) and having a controllable (n+1)/n-way valve (6; 16) with n+1 connections, a first connection (A1) being connected to the water supply, a second connection (A2) being fluidic to a pump inlet (3a) of the pump, a third connection (A3) being connected to the evaporator (4) is connected, a fourth connection (A4) is connected to a pump outlet (3b) of the pump (3) and a fifth connection (A5) is connected to the mixing tank (5), and wherein in a first valve position the first the second port is fluidly connected, the third is fluidly connected to the fourth port and the fifth port is blocked, in a second valve position the first is fluidly connected to the fourth port, the second is fluidly connected to the third port and the fifth port is blocked, in a third valve position the first is fluidically connected to the second port, the fourth is fluidically connected to the fifth port and the third port is blocked and in a fourth valve position the second is fluidically connected to the fifth port, the third with the fourth port is fluidly connected and the first port is blocked.

Description

The invention relates to a household steam cooking appliance having at least four water-conducting components including a water supply, a mixing tank, an evaporator and a pump and also having at least one directional control valve. The invention also relates to a method for operating the domestic steam cooking appliance. The invention can be applied particularly advantageously to household steam cooking appliances with an automatic descaling function, especially in the case of a permanently installed evaporator.

DE 10 2015107 597 A1 discloses a cleaning method for a cooking appliance with at least one reservoir for a liquid cleaning agent, which can be supplied to at least one interior of the cooking appliance to be cleaned and removed from the interior after cleaning, with at least one solid cleaning chemical body being introduced into a cleaning agent supply device in which Detergent supply device is liquefied by adding solvent, a predetermined portion of the cleaning chemical body, and the liquefied portion is part of the liquid detergent in the reservoir.

DE 10 2017 114 253 A1 discloses a household appliance comprising a treatment chamber and a flow-through heating device for heating a fluid, the flow-through heating device comprising a heating section, a heating device and a pump device. In this case, the heating section has a first access and a second access, which are fluidically connected to one another. The pump device can be connected to the heating section, so that a fluid can be supplied to at least one access point by means of the pump device. The heating device is connected to the heating section in a heat-transferring manner at least in sections in order to heat the fluid flowing through the heating section. Furthermore, a multi-way valve is provided between the pump device and the heating section, with the first access, the second access and the pump device being connected to the multi-way valve so that the direction of flow through the heating section can be reversed by actuating the multi-way valve. When operating the household appliance, the direction of flow of the fluid through the heating section is reversed as required by means of the multi-way valve.

DE 10 2009 059 263 B4 discloses a device with a steam generator for generating water vapor from water and/or a hot water generator for generating hot water, with a water connection to a water supply facility, with a device for descaling water-bearing or steam-bearing parts, with a control device that the device for descaling is assigned in order to automatically put the device into a state of descaling operation during a break in operation, characterized in that the control device initiates the descaling operation independently of state-dependent parameters or an operating time and that the device for descaling has a means for removing water from the water supply device has the water connection in order to take water from the water supply device during the descaling operation, has a means for treating the water taken from the water supply device in order to lower the pH value of the water taken off, and a means for supplying treated water to the water-carrying or steam-carrying parts, wherein the means for removing water comprises at least one branch of at least one first line leading from the water supply device to a steam generator or to a hot-water generator and at least one shut-off element, which is arranged in at least one line branching off at the branch, which is means for treatment, and wherein the means for supplying treated water comprises at least one junction into the at least first line, the junction being arranged between the branch and the steam generator or the hot water generator and a line opening at the junction containing the means for treatment connects to the first line.

DE 10 2019 206 323 A1 discloses a steam treatment device with a steam treatment chamber that has a fixed water connection, a receiving container that can be filled with fresh water by means of the fixed water connection and has a drain opening, a steam generator that is arranged outside of the steam treatment space and whose water inlet can be fluidically connected to the drain opening of the receiving container and has a water outlet that can be fluidically connected to the receiving container, at least one pump, a cleaning agent inlet that can be fluidly connected to the receiving container, a temporary waste water outlet, and a valve system that can be switched between at least two switching positions, wherein in a first switching position a closed liquid circuit is formed at least with the receiving container, the steam generator and at least one pump is formed as components bypassing the steam treatment space, and in a second switch position the circuit for connecting the water outlet of the steam generator to the temporary waste water connection is open.

EP 1 430 823 A1 discloses a device for descaling a steam generator, comprising a reservoir which is connected to the steam generator via a connecting line. A controllable dosing device and a controllable shut-off valve are provided within the connecting line, which ensure that the required amount of decalcifying agent gets into the steam generator at the right time. The dosing device and the shut-off valve are monitored by a control device or regulating device which is also connected to devices for determining the degree of calcification.

EP 2 527 732 A1 discloses a steam generator for an ironing station, comprising a water tank, a boiler with a heating element for evaporating the water in the boiler, a water supply device for the metered supply of water from the tank into a boiling chamber of the boiler, the boiler having a steam outlet for connecting a steam line, to which a hand-held appliance can be connected, and an outlet means for draining the water from the boiling chamber to drain it completely, the outlet means and the water supply means being able to be activated automatically by means of control means. In order to make maintenance as simple as possible, the control device is set up to activate the water supply device and the outlet means in such a way that an automatic descaling cycle for the boiling chamber takes place.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide a possibility for automatic decalcification of an evaporator in a domestic steam cooking appliance, which can be implemented in a particularly compact manner and enables particularly user-friendly decalcification.

This object is solved according to the features of the independent claims. Preferred embodiments can be found in particular in the dependent claims.

The object is achieved by a household steam cooking appliance, having n ≥ 4 water-carrying components including a water supply, a tank (hereinafter referred to as "mixing tank" without restriction of generality), an evaporator and a pump and having a controllable (n+1) /n-way valve. A first port of the directional valve is fluidly connected to the water supply, a second port is fluidly connected to a pump inlet, a third port is fluidly connected to the evaporator, a fourth port is fluidly connected to a pump outlet and a fifth port is fluidly connected to the mixing tank. The directional control valve can be controlled in such a way that in a first valve position the first port is fluidly connected to the second port, the third port is fluidly connected to the fourth port and the fifth port is blocked, and in a second valve position the first port is connected to the fourth port is fluidly connected, the second port is fluidly connected to the third port and the fifth port is blocked, in a third valve position the first port is fluidly connected to the second port, the fourth port is fluidly connected to the fifth port and the third port is blocked, in a fourth valve position the second port is fluidically connected to the fifth port, the third port is fluidly connected to the fourth port and the first port is blocked.

This steam cooking appliance has the advantage that the liquid paths used for a steam treatment operation and for an automatic cleaning process, in particular a descaling process, of the steam cooking appliance can be provided by means of a single liquid valve, which enables a particularly compact design. In addition, such a structure can be implemented particularly inexpensively. In addition, the multi-way valve makes it possible to dispense with further conveying devices apart from the one pump. Another advantage is that the multi-way valve clearly separates the individual water-carrying components.

In addition, an automatic descaling process can advantageously take place, in which a user only needs to interact a little with the device, thus avoiding incorrect operation by the customer and also eliminating a time-consuming maintenance step for the user. This function can be designed to be particularly user-friendly, especially in combination with a fixed water device. In addition, a resource-saving use of cleaning agents and water is possible, so that less water is required for the individual cleaning process in order to maintain the functionality of the evaporator. Furthermore, this can save energy in the evaporator.

The household steam cooking appliance is set up for steam cooking or other steam treatment of food with wet steam and/or superheated steam. It is a further development that the steamer is an independent steamer, eg a steamer drawer. In another development, the household steamer can also treat food without steam, for example with radiant heat and/or microwaves. The steam cooking appliance can then in particular be an oven and/or a microwave oven with additional steam treatment functionality (eg known as “added steam”).

The steam cooking appliance typically has a cooking space that can be loaded with food to be cooked through a loading opening on the front that can be closed by means of a door. The cooking chamber is delimited by a cooking chamber wall, e.g. a muffle or an oven, and the closed door. The water supply, the mixing tank, the evaporator, the drain, the pump and the directional control valve are arranged in particular outside the cooking space. In a further development, a vapor outlet of the evaporator is fluidically connected to the cooking chamber. The evaporator or steam generator has an evaporator cavity in which the water supplied is brought to the boil and the resulting steam flows through the steam outlet into the cooking chamber, possibly with prior heating to superheated steam. Since water is usually calcareous, the evaporator cavity is particularly susceptible to calcification and should be descaled at appropriate times.

In a further development, the evaporator or the evaporator cavity is assigned a device for determining the degree of calcification of the evaporator or the evaporator cavity (hereinafter also referred to as “calcification determination device”). This is advantageous in order to be able to choose a point in time for automatically triggering a cleaning process or for outputting a message to the user for triggering a cleaning process as suitably as possible, namely when the calcification has reached or exceeded a certain level. In particular, unnecessary cleaning processes or cleaning that is too late can be avoided. Furthermore, the advantage is achieved that a concentration of the cleaning agent, which also has a decalcifying function, can be adjusted via the degree of calcification.

In particular, during each use of the evaporator, the water hardness of the water used to generate steam in the evaporator can be determined with the aid of a water hardness sensor, e.g. based on the measurement of the electrical conductivity. From the determined water hardness, the degree of calcification of the evaporator can be determined, for example, by adding it up. The determined degree of calcification then forms the basis for the cleaning or decalcification process, e.g. the determination of the decalcification time with or after exceeding a specified threshold value.

A “water-carrying component” can be understood in particular as a device component that is used for providing (e.g. the water supply), storing (tanks in general), conveying (e.g. the pump), discharging and/or treating (e.g. the mixing tank for mixing with cleaning agent, the Evaporator for boiling) of liquid (e.g. water or water-containing mixtures) is provided. Components that define a liquid path, such as liquid lines (e.g. hoses or pipes) and the (n+1)/n-way valve are not understood as water-carrying components in this sense.

The water supply is a device that serves to provide water, in particular fresh water, for a steam treatment process and, if necessary, to produce a cleaning liquid.

The mixing tank serves as a liquid reservoir in which water drawn in from the water supply is mixed with cleaning agent and the mixture is kept as cleaning liquid.

The cleaning agent can in particular be in the form of a water-soluble solid, e.g. granules, especially as a pressed granulate tablet (so-called “tab”), which makes it particularly user-friendly to handle. In one development, the cleaning agent is at least one decalcifying agent, but can also have other chemical agents, e.g. antimicrobial agents, which are provided, for example, to prevent or eliminate biofilms.

The (n+1)/n-way valve has (n+1) used, in particular exactly (n+1) connections for liquid lines such as hoses, pipes, etc., which each lead to one of the water-carrying components. The (n+1)/n-way valve also has n used valve positions, in particular exactly n possible valve positions. In the simplest case n=4, the (n+1)/n-way valve is a 5/4-way valve. If a water-carrying component is added, e.g. a drain as detailed below, n = 5 and the (n+1)/n-way valve is a 6/5-way valve, etc. for other water-carrying components.

The fact that the directional control valve is a controllable directional control valve means that all valve positions can be adjusted in a targeted manner by external control, for example by means of a control device of the steam cooking appliance.

In a further development, the directional valve is a directional valve that can be switched by a motor, ie the valve positions can be adjusted by actuating a motor, in particular an electric motor. If the electric motor is not actuated, the directional control valve remains in its last set valve position.

The fact that the second connection is fluidly connected to the pump inlet of the pump includes, in particular, that the second connection is connected to the suction-side connection or the suction side of the pump, eg via a liquid line such as a hose or a pipe.

The fact that the third connection is fluidically connected to the evaporator includes, in particular, that the third connection is connected to the evaporator cavity, e.g. via a liquid line such as a hose or a pipe. In particular, liquid can be conveyed or pumped into the evaporator cavity and liquid can be conveyed or pumped out of the evaporator cavity. For this purpose, the liquid line can open into the cavity, e.g. in the area of the bottom of the cavity.

The fact that the fourth connection is fluidly connected to the pump outlet of the pump includes, in particular, that the fourth connection is connected to the pressure-side connection or the pressure side of the pump, e.g. via a liquid line such as a hose or a pipe.

In particular, liquid can be conveyed or pumped into the mixing tank and liquid can be conveyed or pumped out of the mixing tank.

In the first valve position, when the pump is operating, water can be sucked in from the water supply to the pump inlet and further pressed from the pump outlet to the evaporator or into the evaporator cavity. This is useful, for example, for refilling the evaporator during steam cooking. If there is a drain, fresh water can also be pumped into the evaporator cavity to flush the evaporator of cleaning agent residues.

In the second valve position, when the pump is operating, water can be sucked out of the evaporator to the pump inlet and further pushed from the pump outlet to the water supply. This corresponds to the reversed flow of the first valve position and can be useful, for example, in order to pump back the residual water remaining in the evaporator or the evaporator cavity to the water supply after the end of evaporator operation. This in turn saves water and prevents formation of a biofilm in the evaporator. If there is no outlet, used cleaning liquid can also be conveyed back into a tank that serves as a water supply, from which the used cleaning liquid can then be emptied by a user.

In the third valve position, when the pump is operating, water can be drawn in from the water supply to the pump inlet and further pushed from the pump outlet to the mixing tank. This advantageously enables the water conveyed into the mixing tank to be mixed with at least part of the water-soluble cleaning agent located in the mixing tank, in particular at least one cleaning agent tab, to form cleaning liquid.

In the fourth valve position, liquid, in particular cleaning liquid, can be sucked out of the mixing tank to the pump inlet during operation of the pump and further pressed or conveyed from the pump outlet into the evaporator. This advantageously allows the evaporator cavity to be filled with the cleaning liquid and thus its decalcification and, if necessary, biological cleaning.

In all of the above valve positions, the pump outlet and the pump inlet are each connected to one of the other water-carrying components, while the remaining water-carrying components are blocked. Thus, four ports are in use at each of the valve positions.

In one embodiment, the domestic steam cooking appliance additionally has a water-carrying component in the form of a drain which is fluidically connected to a sixth connection of the directional control valve, the sixth connection is blocked in the first to fourth valve positions and the second connection is blocked in a fifth valve position is fluidly connected to the third port, the fourth port is fluidly connected to the sixth port, and the first port and the fifth port are blocked. This is particularly advantageous if the evaporator is rinsed through once or several times after it has been exposed to cleaning liquid, since it is thus ensured that a (post-) rinsing process is carried out with fresh water.

In this embodiment, the (n+1)/n-way valve is in particular a 6/5-way valve with 6 ports and five valve positions, of which the first five ports and the first four valve positions correspond to the ports and valve positions set out above. In the fifth valve position, liquid, in particular residual water, used cleaning liquid or rinsing water, can be sucked out of the evaporator during operation of the pump and further pressed or conveyed from the pump outlet into the drain.

The drain is used to drain liquid that is not reused or reusable from the steamer, e.g. used cleaning liquid, rinsing liquid, etc.

In one embodiment, the drain is a drain pipe through which the liquid conveyed here can flow directly out of the device.

In one configuration, the drain is a drain tank that can be emptied by the user. This is particularly advantageous if the device cannot be connected to a house drainage system. In a further development, the drain tank can be removed for emptying. In another development, the drain tank is connected to a liquid line, e.g. hose, arranged e.g. The end of the liquid line on the user side can, for example, be hidden behind a front panel of the device so that it is accessible to the user.

In one embodiment, the mixing tank is a reservoir or tank that can be filled with water-soluble cleaning agent. This achieves the advantage that with and after flushing in water, by at least partially dissolving the cleaning agent and mixing it with the water, a cleaning liquid, in particular with a decalcification effect, can be generated and stored, which can then be used for cleaning, in particular decalcification, of the evaporator. In this way, an automatic cleaning process is made possible in a particularly simple manner, in which a user only needs to provide the cleaning agent in the mixing tank.

It is a further development that the cleaning agent is in the form of at least one, in particular several, cleaning agent tabs.

In a further development, the mixing tank is a tank that can be removed from the device by the user, which advantageously facilitates filling with the cleaning agent, especially tabs. The removed mixing tank can in particular be inserted or pushed into a receptacle provided for this purpose in the steamer and connected to the fifth connection via this receptacle. The fact that the fifth connection is fluidically connected to the mixing tank can therefore include the fifth connection being fluidically connected to the mixing tank receptacle, into which the mixing tank as such can be inserted.

Alternatively, the mixing tank can be permanently installed in the steamer, and only one device that can be arranged in or on the mixing tank for storing the cleaning agent, in particular in the form of tabs, can be removed by the user.

In one embodiment, the mixing tank or the storage device has a water-permeable support for cleaning tabs, which can be flushed from below with water supplied via the fifth connection. This results in the advantage that the cleaning agent, in particular cleaning agent tabs, can only be partially dissolved in a targeted manner in order to provide a cleaning liquid with a specifically adjustable concentration of cleaning agent.

In a further development, the mixing tank is assigned a sensor (hereinafter referred to as “concentration sensor” without loss of generality), which is set up to measure the concentration of the cleaning agent in the cleaning liquid. Once the desired concentration has been reached, the water supply to the mixing tank can be stopped and/or the cleaning liquid can be pumped out through the fifth connection and pumped into the evaporator. For this purpose, the concentration sensor can be connected to a control device, which also controls the directional control valve, the evaporator and the pump. As an alternative to a concentration sensor, the concentration of the cleaning agent can be adjusted, for example, via the duration of the flushing or contacting of the cleaning agent with the supplied water.

In a further development, a calcification determination device is assigned to the evaporator and the concentration of the cleaning agent in the cleaning liquid is determined on the basis of the degree of calcification determined by the calcification determination device. This achieves the advantage that subsequent rinsing of the evaporator can be dispensed with or the amount of rinsing water can be kept particularly low. In particular, the higher the degree of calcification, the higher the concentration of the cleaning agent.

The water-permeable covering can be in the form of a screen, for example made of plastic.

In one configuration, the directional control valve has a rotatable disk (referred to below as “valve disk” without restricting the generality) with a plurality of channels such that n angular positions of the valve disk correspond to a respective valve position. In each of the rotary positions, the pump inlet is connected to another water-carrying component through the valve disk and the pump inlet is connected to yet another water-carrying component. The remaining water-carrying component(s) is (are) blocked or blocked fluidically by the valve disk.

In one configuration, the valve disk is arranged to be rotatable, pressed flatly between a first outer disk and a second outer disk. A particularly compact and reliable valve construction is thus provided. that the valve disc is arranged to be rotatable between a first outer disc and a second outer disc, pressed flat, includes in particular that the valve disc is arranged between the outer discs in a “sandwich” arrangement and the outer discs press on the valve disc in the opposite direction, i.e. pressing it between them hold. The outer disks are arranged in a stationary manner, in particular in relation to a valve housing, and the valve disk can be rotated relative to the outer disks. In order to achieve a reproducible prestressing force, one or more, in particular three, spring elements, eg spiral springs, are stretched between two housing parts and the force for pressing the valve disk is thus transmitted to the outer disks.

The outer disks have holes that can be placed in particular congruently on the channels of the valve disk and then form corresponding fluid passages. On the other hand, the holes are connected to respective connections, in the case of a 6/5-way valve in particular in such a way that the first outer disk and the second outer disk each have three holes. The connections can be implemented, for example, on housing parts of the directional control valve, e.g. in the form of connecting pieces protruding outwards from the housing, to which respective hoses can be attached.

The contact surfaces of the discs with one another are, in particular, flat. It is advantageous if the discs are made of a material with good sealing and sliding properties, because then there is no need to seal the directional control valve, e.g. by means of its housing, or at least a seal that can be produced with little effort is sufficient. In one embodiment, a suitable material is ceramic, for example aluminum oxide ceramic, e.g. with a degree of purity of 99.8%, but also, among other things, SiC, SiAlOn, etc. However, a suitable material can also be metal and/or plastic, particularly if it is a base body made of metal and/or plastic has a surface coating (e.g. made of ceramic or metal) and/or is microstructured on its surface.

In one configuration, the valve disc can be rotated by means of a drive, in particular an electric motor. The various valve positions are set via the drive and the gear that drives the valve disc. In one embodiment, the valve disk can be rotated by means of the electric motor via a gear. The transmission is advantageously a gear transmission, but is not limited to this. In particular, the edge of the valve disk is provided with a ring gear, in which the teeth of the gear train can engage.

In one embodiment, a position or angle of rotation determination device is assigned to the valve disk. In this way, the achievement of a specific angle of rotation and thus the valve position can advantageously be monitored accurately and reliably over the long term. In a further development, the determination device comprises two light barriers, with the number of engine revolutions being able to be monitored by means of the first light barrier and the zero position of the valve disc being monitored by means of the second light barrier. However, the position monitoring determination device can also be implemented by an incremental measuring system, mechanical tappets or other sensors, e.g. magnetic, inductive or capacitive sensors.

It is an embodiment that the water supply is a fixed water connection. This is particularly user-friendly, since the user does not have to provide fresh water himself, this is done automatically. The fixed water connection has in particular a controllable shut-off valve.

In one embodiment, the water supply is a tank or reservoir (hereinafter referred to as “fresh water tank” without restricting the generality). This has the advantage that automatic cleaning is also possible in the event that no fixed water connection is available. The presence of the fresh water tank has the further advantage that it can be used as a receptacle for used cleaning liquid, e.g. if there is no separate or dedicated drain. In addition, residual water that is not used in a steam treatment process can then be pumped back into the fresh water tank and used again in a next steam treatment process. Furthermore, unpressurized fresh water can advantageously be sucked in by the pump.

The fresh water tank can in particular be removable, which facilitates filling with fresh water and possibly emptying used cleaning liquid in contrast to a permanently installed fresh water tank with water inlet and possibly water outlet and also facilitates its cleaning. It is a further development that the fresh water tank is dishwasher safe.

It is a further development that the water supply has a fresh water tank, which can in particular be removed by the user and which can be filled with fresh water by means of a fixed water connection. This has the advantage that the user does not have to provide fresh water himself and the fresh water tank can also be used as a collection container for liquid that has been pumped back (eg residual water, cleaning liquid and/or rinsing water).

The object is also achieved by a method for operating a household steam cooking appliance as described above, in which before and/or during a steam cooking operation in the first valve position of the (n+1)/n-way valve, water is pumped out of the fresh water tank through the pump into the Evaporator is funded and optionally during and / or after Dampfgarbetrieb in the second valve position, water from the evaporator is funded by the pump back into the fresh water tank. For example, the evaporator can be filled or refilled with water, in particular fresh water, to generate steam, and optional residual water that has not been used can be pumped back into the fresh water tank. The latter is particularly effective in preventing the water from standing in the evaporator and thus possibly preventing the formation of a biofilm. The rate of calcification of the evaporator or the evaporator cavity can also be reduced in this way.

The transition between different valve positions can generally take place by operating, in particular energizing, the drive, in particular an electric motor, of the directional control valve.

The method can be designed analogously to the household steam cooking appliance and vice versa, and has the same advantages.

The object is also achieved by a method for cleaning, in particular decalcification, of the evaporator, in which first, in the third valve position, water is conveyed from the water supply, in particular the fresh water tank, through the pump into the mixing tank in order to produce cleaning liquid there, then in In the fourth valve position, the cleaning liquid is conveyed from the mixing tank to the evaporator by the pump and then, particularly after a certain exposure time has elapsed, if there is no drain, in the second valve position the used cleaning liquid is conveyed from the evaporator to the fresh water tank by the pump , and then if there is a drain, in the fifth valve position the used cleaning liquid is conveyed from the evaporator by the pump to the drain.

This method can also be designed analogously to the household steam cooking appliance and vice versa, and has the same advantages.

It is a further development that the method for cleaning, in particular decalcification, of the evaporator is triggered automatically or by a user if a device for determining the degree of calcification of the evaporator or the evaporator cavity (hereinafter also referred to as "calcification determination device") has been determined is that the calcification has reached or exceeded a certain level.

In one embodiment, when there is a drain, for flushing the evaporator, in the first valve position, water is then pumped from the water supply, in particular from the fresh water tank, through the pump into the - in particular deactivated or only with little energy (i.e., with not enough energy to bring the water to a boil) operated - evaporator is conveyed and then in the fifth valve position flushing water from the deactivated evaporator is conveyed through the pump to the drain. This method can also be designed analogously to the household steam cooking appliance and vice versa, and has the same advantages.

• 1 zeigt eine Skizze eines Haushalts-Dampfgargeräts mit vier wasserführenden Komponenten;
• 2 zeigt eine Schaltskizze eines 5/4-Wegeventils des Haushalts-Gargeräts aus 1;
• 3 zeigt als Schnittdarstellung in Seitenansicht eine Skizze einer möglichen Variante des Mischtanks 5
• 4 zeigt eine Skizze von Komponenten eines Haushalts-Gargeräts mit fünf wasserführenden Komponenten;
• 5 zeigt eine Schaltskizze eines 6/5-Wegeventils des Haushalts-Gargeräts aus 4; und
• 6 zeigt als Schnittdarstellung in Seitenansicht eine Skizze eines möglichen 6/5-Wegeventils.

The characteristics, features and advantages of this invention described above, and the manner in which they are achieved, will become clearer and more clearly understood in connection with the following schematic description of an exemplary embodiment, which will be explained in more detail in connection with the drawings.

• 1 shows a sketch of a household steamer with four water-bearing components;
• 2 shows a circuit diagram of a 5/4-way valve of the household cooking appliance 1 ;
• 3 shows a sectional side view of a sketch of a possible variant of the mixing tank 5
• 4 shows a sketch of components of a household cooking appliance with five water-bearing components;
• 5 shows a circuit diagram of a 6/5-way valve of the household cooking appliance 4 ; and
• 6 shows a sketch of a possible 6/5-way valve as a sectional side view.

1 shows a sketch of a domestic steam cooking appliance 1 with four water-carrying components, namely a water supply in the form of a user-side and/or via a fixed water supply Connection with fresh water fillable fresh water tank 2, a pump 3 with a pump inlet 3a and a pump outlet 3b, an evaporator 4 and a mixing tank 5. The household steam cooking appliance 1 also has a controllable 5/4-way valve 6 with five connections A1 to A5, from which a first port A1 is fluidly connected to the fresh water tank 1, a second port A2 is fluidly connected to the pump inlet 2a, a third port A3 is fluidly connected to the evaporator 4, a fourth port A4 is fluidly connected to the pump outlet 2b and a fifth port A5 is fluidly connected to the mixing tank 5.

The pump 3, a heating device of the evaporator 4, and the 5/4-way valve 6 can be controlled by a control device 7. The control device 7 is also coupled to a number of sensors, such as a concentration sensor 8 of the mixing tank 5 and a water hardness sensor 9 of the evaporator 4. The control device 7 is in particular set up, e.g. programmed, to allow the cooking product treatment operating modes to run, e.g at least one cleaning operation or process for cleaning the evaporator 4. It is also set up to determine the degree of calcification of the evaporator 4 from the measurement data from the water hardness sensor 9 and from this in turn to define a target cleaning agent concentration in the mixing tank 5.

The control device 7 can also, for example, control one or more radiant heating elements heating a cooking space, such as a bottom heating element, a top heating element, a ring heating element, etc. and/or a microwave generator (not illustrated). Steam generated by the evaporator 4 is also conducted into the cooking chamber.

As now also based on an in 2 shown circuit diagram of the 5/4-way valve 6 with the possible valve positions drawn in from left to right, this can be motor-driven by a control device 7 in such a way that in a first valve position the first port A1 is fluidically connected to the second port A2, the third Port A3 is fluidically connected to the fourth port A4 and the fifth port A5 is blocked. In a second valve position, the first port A1 is fluidically connected to the fourth port A4, the second port A2 is fluidically connected to the third port A3 and the fifth port A5 is blocked. In a third valve position, the first port A1 is fluidically connected to the second port A2, the fourth port A4 is fluidically connected to the fifth port A5, and the third port A3 is blocked. In a fourth valve position, the second port is fluidically connected to the fifth port, the third port is fluidically connected to the fourth port, and the first port is blocked.

During a steam cooking operation, before and/or during steam generation by the evaporator 4 with the 5/4-way valve 6 in the first valve position, water can be pumped from the fresh water tank 2 through the pump 3 into the evaporator 4 and brought to the boil there. During and/or after steam generation, with the 5/4-way valve 6 in the second valve position, residual water from the evaporator 4 can be pumped back into the fresh water tank 2 by the pump 3 .

If it is recognized on the basis of the measurement data from the water hardness sensor 9 that the degree of calcification in the evaporator 4 or its evaporator cavity is so high that a decalcification process makes sense, e.g. by comparison with a threshold value, a cleaning process can be suggested to a user, e.g. via a display ( o. Fig.) Of the household steamer 1 and / or an output of a message to a mobile user terminal. The cleaning process can then be triggered by the user. Alternatively, the household steamer 1 can trigger the cleaning process automatically.

As part of the cleaning process, water can first be pumped from the fresh water tank 2 through the pump 3 into the mixing tank 5 in the third valve position, in order to generate cleaning liquid there by partially dissolving the cleaning agent tabs contained therein as a result of flushing them with the water supplied. If the concentration sensor 8 has detected that the cleaning agent concentration is suitable for cleaning the evaporator 4, the 5/4-way valve 6 is switched to its fourth valve position by the control device 7 and the cleaning liquid from the mixing tank 5 is pumped through the pump by activating the pump 3 3 is conveyed into the evaporator 4. The cleaning liquid remains there for a suitable period of time. The 5/4-way valve 6 is then switched to its second valve position by the control device 7 and the used cleaning liquid is conveyed from the evaporator 4 through the pump 3 to the fresh water tank 2 by activating the pump 3 . A user can dispose of the used cleaning liquid, for example, by removing and emptying the fresh water tank 2 .

3 shows a sectional side view of a sketch of a possible variant of the mixing tank 5. The mixing tank 5 has a housing 10 that a user in a corresponding, with the fifth connection A5 fluidically ver Bonded recording (o. Fig.) Of the steamer 1 can be used, in particular can be inserted. A tube 11 runs in the housing 10 to its lowest point, which is provided at one end for flushing in water and sucking off cleaning liquid. The tube 11 can be fluidically connected at its other end 12 to a connection of the receptacle, for example can be plugged into it, the connection of the receptacle being fluidically connected to the fifth connection A5. If the water level rises due to water that has been flushed in or pushed in, the water comes into contact with a water-permeable support for cleaning tabs RT, e.g then a little further, so that the cleaning tabs RT (only) are flushed with water on their lower areas. The cleaning tabs RT are consequently dissolved from below until a desired concentration of cleaning agent has been reached. If this is the case, the cleaning liquid produced in this way is pumped out through the pipe 11 . Typically, the cleaning tabs RT are not completely but only partially dissolved, so that a full load of cleaning tabs is sufficient for several cleaning processes. If the cleaning tabs RT have been completely dissolved, a message can be issued to a user so that he can remove the mixing tank 5 and enter new cleaning tabs RT into the storage facility 14 .

The concentration sensor 8 can be arranged on the mixing tank 5 and/or in the receptacle (not shown), or a concentration sensor 8 can be dispensed with.

4 shows a sketch of a household steamer 15 with five water-carrying components, namely as in the household steamer 1, the fresh water tank 2, the pump 3, the evaporator 4 and the mixing tank 5. In contrast to the household steamer 1, there is now a controllable 6/5-way valve 16 with six ports A1 to A6, of which the ports A1 to A5 are connected as in the household steamer 1 and a sixth port A6 is also present , which is fluidically connected to a drain in the form of a drain tank 17 . The drain tank 17 can, for example, be emptied by a user via a closable drain line (not shown) or can itself be removed for emptying.

As now also based on an in 5 shown circuit diagram of the 6/5-way valve 16 with the possible valve positions drawn from left to right, this can be motor-driven by a control device 7 in such a way that the first to fourth valve positions A1 to A4 result analogously to the 5/4-way valve 1 , the sixth connection A6 being blocked in each case. There is now an additional fifth valve position, in which the first port A1 and the fifth port A5 are blocked, the third port A3 is fluidically connected to the second port A2 and the fourth port A4 is fluidly connected to the sixth port.

This is particularly advantageous if the cleaning liquid is not to get into the fresh water tank 2: after the cleaning liquid has remained in the evaporator for a suitable period of time, the 6/5-way valve 16 can be switched over to its fifth valve position by the control device 7 and by activating the Pump 3, the used cleaning liquid from the evaporator 4 are conveyed by the pump 3 into the drain tank 17. In addition, at least one rinsing cycle can follow, in which, in the first valve position of the 6/5-way valve 16, water is conveyed from the fresh water tank 2 by the pump 3 into the evaporator 4, which is in particular deactivated or operated with little energy, and then in the fifth valve position of the 6/5-way valve 16, the resulting flushing water is pumped out of the evaporator 4 into the drain tank 17 by the pump.

6 shows a sectional side view of a sketch of a possible 6/5-way valve 16. The 6/5-way valve 16 has a valve disk 19 that can be rotated by means of an electric motor M via a gear 18 about its longitudinal or symmetrical axis. For this purpose, the electric motor M can, for example, have a shaft in the form of a worm wheel (not shown), which rotates a gear (not shown), which in turn rotates a toothed ring (not shown) associated with the valve disk 19 . The axis of rotation is perpendicular to the image plane.

The valve disk 19 is arranged between an upper first outer disk 20 arranged parallel thereto and a lower second outer disk 21 also arranged parallel. Forces F act on the first outer disk 20 and the second outer disk 21, which push or press the outer disks 20, 21 flat onto the valve disk 19, so that gaps between them are practically avoided, but the valve disk 19 remains rotatable. The discs 19 to 21 are advantageously made of ceramic.

The valve disc 19 is equipped with several channels such as holes, grooves, etc. (not shown), while three connection channels lead through the first outer disc 20 to the valve disc 19, which at its other end is connected to the connections A1, A3 and A5 are connected. Lead by analogy through the second outer disk 21 three connection channels to the valve disk 19, which are connected at their other end to the ports A2, A4 and A6. By turning the valve disk 19, five angular positions can be assumed, which correspond to those in 5 correspond to the valve positions shown. For example, the first to fifth valve positions can be assumed at angles of rotation of the turntable 19 of 0°, 90°, 220°, 60° or 120°. The angles of rotation are detected via the device 22 for determining the angle of rotation, and the measurement data from the device 22 for determining the angle of rotation are used by the control device 7 to control the motor M.

Of course, the present invention is not limited to the embodiment shown.

So the 5/4-way valve 6 can 6 have an analog structure.

In general, "a", "an" etc. can be understood as a singular or a plural number, in particular in the sense of "at least one" or "one or more" etc., as long as this is not explicitly excluded, e.g. by the expression "exactly a" etc.

A numerical specification can also include exactly the specified number as well as a usual tolerance range, as long as this is not explicitly excluded.

Reference List

1

household steamer

2

fresh water tank

3

pump

3a

pump inlet

3b

pump outlet

4

Evaporator

5

mixing tank

6

5/4 way valve

7

control device

8th

concentration sensor

9

water hardness sensor

10

Housing

11

Pipe

12

end of the pipe

13

Floor

14

storage facility

15

household steamer

16

6/5 way valve

17

drain tank

18

transmission

19

valve disc

20

First outer pane

21

Second outer pane

22

rotation angle determination device

A1-A6

Connections of a directional control valve

f

Power

M

electric motor

rt

cleaning tab

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102015107597 A1 [0002]
• DE 102017114253 A1 [0003]
• DE 102009059263 B4 [0004]
• DE 102019206323 A1 [0005]
• EP 1430823 A1 [0006]
• EP 2527732 A1 [0007]

Claims (14)

Household steamer (1; 15), having n ≥ 4 water-bearing components including - a water supply (2), - a mixing tank (5), - an evaporator (4) and - a pump (3) - and having a controllable (n+1)/n-way valve (6; 16) with n+1 connections (A1-A5; A1-A6), wherein - a first connection (A1) is fluidically connected to the water supply (2), - a second connection (A2) is fluidly connected to a pump inlet (3a) of the pump (3), - a third connection (A3) is fluidically connected to the evaporator (4), - A fourth connection (A4) is fluidly connected to a pump outlet (3b) of the pump (3) and - A fifth connection (A5) is fluidly connected to the mixing tank (5), and wherein the directional control valve (6; 16) can be controlled in such a way that - In a first valve position, the first port (A1) is fluidically connected to the second port (A2), the third port (A3) is fluidly connected to the fourth port (A4) and the fifth port (A5) is blocked, - In a second valve position, the first port (A1) is fluidically connected to the fourth port (A4), the second port (A2) is fluidically connected to the third port (A3) and the fifth (A5) port is blocked, - In a third valve position, the first port (A1) is fluidically connected to the second port (A2), the fourth port (A4) is fluidically connected to the fifth port (A5) and the third port (A3) is blocked and - In a fourth valve position, the second port (A2) is fluidly connected to the fifth port (A5), the third port (A3) is fluidly connected to the fourth port (A4) and the first port (A1) is blocked. Household steamer (15) after claim 1 , wherein - the household steam cooking appliance (15) additionally has a water-carrying component in the form of a drain (17) which is fluidically connected to a sixth connection (A6) of the directional control valve (16), - the sixth connection (A6) in the first to the fourth valve position is blocked and - in a fifth valve position the second port (A2) is fluidically connected to the third port (A3), the fourth port (A4) is fluidically connected to the sixth port (A6) and the first port (A1 ) and the fifth connection (a5) are blocked. Household steamer (1; 15) after claim 2 , wherein the drain (17) is a drain pipe or a drain tank (17) that can be emptied by the user. Household steam cooking appliance (1; 15) according to any one of the preceding claims, wherein the mixing tank (5) is a tank, in particular a removable tank, which can be loaded with cleaning agent (RT). Household steamer (1; 15) after claim 4 , wherein the mixing tank (5) has a water-permeable support (13) for cleaning tabs (RT) which can be flushed from below with water supplied via the fifth connection (A5). Household steam cooking appliance (1; 15) according to one of the preceding claims, wherein the directional control valve (6; 16) has a motor-driven rotatable valve disk (19) with a plurality of channels such that n angular positions of the valve disk (19) correspond to a respective valve position. Household steamer (1; 15) after claim 6 , wherein the valve disk (19) is arranged to be rotatable between a first outer disk (20) and a second outer disk (21), pressed flat and with the outer disks (20, 21) having holes which are connected to respective connections (A1-A5; A1-A6 ) are fluidically connected. Household steamer (1; 15) according to one of Claims 6 until 7 , wherein the discs (19-21) are ceramic discs. Household steamer (1; 15) according to one of Claims 6 until 8th , wherein the valve disk (19) can be rotated by means of an electric motor (M) via a gear train (18). Household steamer (1; 15) according to one of Claims 6 until 9 , wherein the valve disc (19) is assigned a rotation angle determination device (22). Domestic steam cooking appliance (1; 15) according to one of the preceding claims, wherein the water supply (2) has a fixed water connection and/or a fresh water tank (2). Method for operating a household steam cooking appliance (1; 15) according to one of the preceding claims, in which - Before and/or during a steam cooking operation in the first valve position, water is conveyed from the fresh water tank (2) through the pump (3) into the evaporator (4) and - During and/or after steam cooking in the second valve position, water is conveyed from the evaporator (4) back into the fresh water tank (2) by the pump (3). Procedure, especially after claim 12 , For cleaning, in particular descaling, the evaporator (4) of the household steamer (1) according to one of Claims 1 until 11 , in which - initially in the third valve position, water is conveyed from the water supply (2) through the pump (3) into the mixing tank (5) in order to produce cleaning liquid there, in particular with a specific cleaning agent concentration, - then in the fourth valve position the Cleaning liquid is conveyed from the mixing tank (5) by the pump (3) into the evaporator (4) and then - if there is no outlet (17) available - in the second valve position the used cleaning liquid from the evaporator (4) by the pump ( 3) is pumped to the fresh water tank (2), while - if there is a drain (17), in the fifth valve position the used cleaning liquid is pumped from the evaporator (4) through the pump (3) to the drain (17). procedure after Claim 13 , in which, if a drain (17) is present, then for flushing the evaporator (4) - in the first valve position, water from the water supply (2), in particular from the fresh water tank, through the pump (3) into the evaporator ( 4) is conveyed and then - in the fifth valve position, rinsing water is conveyed from the evaporator (4) by the pump (3) to the drain (17).

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