Method for cleaning a steam injection system, steam injection system for a cooking appliance and cooking appliance with a cooking chamber

Abstract

The invention relates to a method for cleaning a steam injection system (2) of a cooking appliance with a cooking chamber (4) comprising the following process steps: filling a tank (6) with a cleaning acid until the cleaning acid overflows from the tank (6) into the cooking chamber (4) via an overflow line (16) having a shut-off valve (18); circulating the cleaning acid from the tank (6) to a steam generator (14) and back; filling the tank (6) with fresh water with the shut-off valve (18) closed and the steam generator (14) switched off, until the cleaning acid has been displaced by the fresh water into a bypass line (20) in the cooking chamber (4) which is connected to the steam generator (14) and the overflow line (16) in a flow-conducting manner; Filling the tank (6) with air with the shut-off valve (18) closed until the fresh water has been displaced into the cooking chamber (4) via the bypass line (20);Wet the pump (10) with a predetermined quantity of fresh water, the quantity of fresh water being designed solely for wetting the pump (10); evaporation of any residual water located in the steaming system (2) downstream of the pump (10) by means of the steam generator (14) with the shut-off valve (18) open. Furthermore, the invention relates to a steam injection system (2) and a cooking appliance.

Description

[0001] The invention relates to a method for cleaning a humidification system of a cooking appliance with a cooking chamber, a humidification system and a cooking appliance with a cooking chamber.

[0002] Such methods, steaming systems and cooking appliances are already known from the prior art in a variety of embodiments, for example from the documents DE 10 2007 048 567 A1 and DE 10 2019 125 135 A1 and US 2020 / 0 191 404 A1.

[0003] The invention therefore addresses the problem of improving a method for cleaning a humidification system of a cooking appliance with a cooking chamber, a humidification system and a cooking appliance with a cooking chamber.

[0004] According to the invention, this problem is solved by a method having the features of patent claim 1. Furthermore, this problem is solved by a steaming system having the features of patent claim 5 and by a cooking appliance having the features of patent claim 9. The term "cleaning" is to be interpreted broadly here and includes, in particular, the descaling of the steaming system according to the invention. Advantageous embodiments and further developments of the invention are set forth in the following subclaims.

[0005] The advantage achievable with the invention lies in the fact that a method for cleaning a humidification system of a cooking appliance with a cooking chamber, a humidification system, and a cooking appliance with a cooking chamber are improved. Due to the inventive design of the method, the humidification system, and the cooking appliance, the cleaning of a humidification system of a cooking appliance with a cooking chamber is significantly improved in a very simple manner in terms of design, manufacturing, and circuitry. Furthermore, the humidification system according to the invention and thus the cooking appliance according to the invention can be operated reliably using the method according to the invention even over a long downtime of the cooking appliance according to the invention.In conventional processes, steaming systems, and cooking appliances with cooking chambers, the usual pumping or draining of the saturated cleaning acid is fundamentally critical due to solid suspended particles contained in the cleaning acid. This applies particularly to structurally small steaming systems. This frequently leads to leaks in valves and damage to pumps, for example. The invention provides a remedy for this. Furthermore, the invention achieves the specification of a corresponding process and steaming system in which an additional pump for pumping out the saturated cleaning acid and an additional drain into the cooking chamber for discharging the saturated cleaning acid from the steaming system can be omitted. Furthermore, the invention is suitable for significantly extending the service life, i.e. the overall operating time, of the individual components of the steaming system.This is because, on the one hand, the only pump of the humidification system according to the invention only delivers pure cleaning acid, i.e. cleaning acid without solid particles, pure fresh water and pure air, and, on the other hand, the only shut-off valve is only activated for a short time after prior wetting with liquid.

[0006] In principle, the method according to the invention, the steaming system according to the invention, and the cooking appliance according to the invention can be freely selected within wide, suitable limits. For example, the cooking appliance according to the invention can be a household appliance or a professional appliance, i.e., a cooking appliance for commercial use.

[0007] An advantageous development of the method according to the invention provides that the cleaning acid is citric acid and / or the fresh water is tap water and / or the air is ambient air. This makes it a cleaning acid that is highly suitable for cleaning success, particularly for descaling. Furthermore, citric acid can be used safely in cooking appliances with a cooking chamber for cooking food. On the other hand, fresh water in the form of tap water and air in the form of ambient air are readily available on site.

[0008] A further advantageous development of the method according to the invention provides that the cleaning acid is circulated solely by means of the steam generator, preferably that the steam generator is operated with short heating pulses such that thermal circulation of the cleaning acid occurs. This allows the steaming system according to the invention to be implemented in a particularly simple manner in terms of design, manufacturing, and circuitry. This applies particularly to the preferred embodiment of this development.

[0009] According to the invention, the predetermined amount of fresh water for wetting the pump is less than or equal to 50 ml.

[0010] Another advantageous development of the method according to the invention provides that the predetermined amount of fresh water for wetting the pump is less than or equal to 40 ml, particularly preferably less than or equal to 30 ml. In this way, the amount of fresh water supplied to the humidification system according to the invention in this specific process step of the method according to the invention is kept to a minimum without compromising the function of the method according to the invention and the longevity of the humidification system according to the invention.

[0011] As already indicated above, the humidification system according to the invention can be freely selected in terms of type, mode of operation, material, and dimensions within wide, suitable limits. The humidification system expediently comprises the following components in the specified arrangement: a tank, a filling line connected to the tank in a fluid-conducting manner, with a pump for filling the tank with a fluid, a steam generator connected to the tank by means of a connecting line, an overflow line with a shut-off valve for connecting the tank to the cooking chamber, and a bypass line connected to the tank, the steam generator, and the overflow line for connecting the tank to the cooking chamber of the cooking appliance.

[0012] An advantageous development of the aforementioned embodiment of the humidification system according to the invention provides that the filling line with the pump is fluidly connected to the tank on an upper side of the tank and / or that the steam generator is fluidly connected to the tank on the one hand at a position directly adjacent to the upper side of a side of the tank and on the other hand at an underside of the tank and / or that the overflow line is fluidly connected to the tank on the upper side of the tank and / or that the bypass line is fluidly connected to the tank on the underside. As a result, the individual flow-conducting connections between the individual components of the humidification system according to the invention are implemented in a particularly functional manner.

[0013] A further advantageous development of the humidification system according to claim 6 or 7 provides that the shut-off valve is designed as a pinch valve. Pinch valves, due to the lack of moving parts that come into contact with the cleaning acid, for example, are very wear-resistant and therefore require little maintenance. Accordingly, operating costs are reduced, while the service life of the shut-off valve, i.e., its service life, is extended. In principle, however, other types and functionalities for the shut-off valve are also conceivable.

[0014] An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows Fig. 1 an embodiment of the cooking appliance according to the invention with the humidification system according to the invention for carrying out the method according to the invention in a process diagram, Fig. 2 to 7 the embodiment in analog representation to the Fig. 1, during the individual procedural steps.

[0015] In the Fig. 1 to 7, an embodiment of the cooking appliance according to the invention with the humidification system according to the invention for carrying out the method according to the invention is shown purely by way of example.

[0016] The steaming system 2 for a cooking appliance (not shown in detail) designed as a household steamer with a cooking chamber 4 comprises a tank 6, a filling line 8 connected to the tank 6 in a flow-conducting manner and having a pump 10 for filling the tank 6 with a fluid, a steam generator 14 connected to the tank 6 by means of a connecting line 12 in a flow-conducting manner, an overflow line 16 with a shut-off valve 18 for the flow-conducting connection of the tank 6 to the cooking chamber 4 and a bypass line 20 connected to the tank 6, to the steam generator 14 and to the overflow line 16 in a flow-conducting manner and for the flow-conducting connection to the cooking chamber 4 of the cooking appliance. The cooking appliance (not shown in detail) is in the Fig. 1 to 7 are indicated by a dotted line. Fig. The cooking chamber 4 shown with a dashed line in numbers 1 to 7 does not belong to the steaming system 2 in the strict sense.

[0017] As can be seen from the Fig. 1 to 7, the filling line 8 is fluidly connected to the tank 6 by the pump 10 at an upper side of the tank 6, the steam generator 14 is fluidly connected to the tank 6 at a position directly adjacent to the upper side of the tank 6 and at an underside of the tank 6, the overflow line 16 is fluidly connected to the tank 6 at the upper side of the tank 6, and the bypass line 20 is fluidly connected to the tank 6 at the underside. The shut-off valve 18 is designed as a pinch valve in the present embodiment.

[0018] In the following, the method according to the invention and the functioning of the cooking appliance according to the invention with the humidification system according to the invention according to the present embodiment are explained with reference to the Fig. 1 to 7. Flow-conducting connections through which a fluid flows in the respective process step are shown in the Fig. 2 to 7 symbolized by a thick solid line.

[0019] In a first process step, the tank 6 of the humidification system 2 is filled with a cleaning acid, namely citric acid, by means of the filling line 8 and the pump 10 of the humidification system 2 until the cleaning acid overflows from the tank 6 into the cooking chamber 4 via the overflow line 16 of the humidification system 2, which has the shut-off valve 18. See the Fig. 2. The shut-off valve 18 is open. The cleaning acid is in the Fig. 1 to 7 are not explicitly shown. For the purpose of the aforementioned filling of the tank 6 with the cleaning acid, the filling line 8 has a filler neck 22 upstream of the pump 10, namely at its free end. For example, the filler neck 22 can be immersed in a container filled with the cleaning acid, so that the pump 10 can suck the cleaning acid from the container.

[0020] In one in the Fig. In the second process step shown in Figure 3, the cleaning acid is circulated from the tank 6 into the steam generator 14 of the steaming system 2 and back. The circulation of the cleaning acid takes place solely by means of the steam generator 14, namely in such a way that the steam generator 14 is operated with short heating pulses, so that a thermal circulation of the cleaning acid occurs.

[0021] Subsequently, in a third process step, the tank 6 is filled with fresh water by means of the filling line 8 and the pump 10 with the shut-off valve 18 closed and the steam generator 14 switched off, until the cleaning acid has been displaced by the fresh water into the bypass line 20, which is connected to the steam generator 14 and the overflow line 16, into the cooking chamber 4. See the Fig. 4. The fresh water not explicitly shown is tap water, which, like the cleaning acid, can be filled into the humidification system 2 by means of a container filled with it and the filler neck 22.

[0022] In the Fig. Figure 5 shows a fourth process step in which the tank 6 is filled with air via the filling line 8 and the pump 10 with the shut-off valve 18 closed until the fresh water has been displaced into the cooking chamber 4 via the bypass line 20. The air is ambient air, which can be filled into the humidification system 2 via the filler neck 22.

[0023] In a fifth process step, the pump 10 is wetted with a predetermined amount of fresh water by means of the filling line 8 and the pump 10, whereby the amount of fresh water is designed only to wet the pump 10. This predetermined amount of fresh water for wetting the pump 10 is only 30 ml. See the Fig. 6. The wetting of the pump 10 with fresh water takes place analogously to the third process step.

[0024] Finally, in a sixth process step, a residual amount of water in the steaming system 2 downstream of the pump 10 is evaporated by means of the steam generator 14 with the shut-off valve 18 open. See the Fig. 7.

[0025] Due to the inventive design of the method, the humidification system 2, and the cooking appliance, the cleaning of the humidification system 2 is significantly improved in a very simple manner in terms of design, manufacturing, and circuitry. Furthermore, the humidification system 2 can be reliably operated using the method used, even over a long downtime of the cooking appliance. This applies in particular to structurally small humidification systems, as is the case with the present humidification system 2. Furthermore, an additional pump for pumping out the saturated cleaning acid and an additional drain into the cooking chamber 4 for discharging the saturated cleaning acid from the humidification system 2 can be omitted, compared to the prior art.Furthermore, the service life, i.e., the total operating time, of the individual components of the humidification system 2 is significantly extended compared to conventional systems and cooking appliances equipped with them. This is because, on the one hand, the single pump 10 of the humidification system 2 delivers exclusively pure cleaning acid, i.e., cleaning acid without solid particles, pure fresh water, and pure air, and, on the other hand, the single shutoff valve 18 is only activated for a short time after prior wetting with liquid.

[0026] However, the invention is not limited to the present embodiment. See, for example, the relevant statements in the introduction to the description.

Claims

[1] Method for cleaning a humidification system (2) of a cooking appliance with a cooking chamber (4), according to which the method comprises the following method steps in the specified order: - filling a tank (6) of the humidification system (2) with a cleaning acid by means of a filling line (8) and a pump (10) of the humidification system (2) until the cleaning acid overflows from the tank (6) into the cooking chamber (4) by means of an overflow line (16) of the humidification system (2) having a shut-off valve (18); - Circulating the cleaning acid from the tank (6) into a steam generator (14) of the humidification system (2) and back; - filling the tank (6) with fresh water by means of the filling line (8) and the pump (10) with the shut-off valve (18) closed and the steam generator (14) switched off, until the cleaning acid has been displaced by means of the fresh water into a bypass line (20) in the cooking chamber (4) which is connected in a flow-conducting manner to the steam generator (14) and the overflow line (16); - filling the tank (6) with air by means of the filling line (8) and the pump (10) with the shut-off valve (18) closed, until the fresh water has been displaced into the cooking chamber (4) by means of the bypass line (20); - Wetting the pump (10) with a predetermined amount of fresh water by means of the filling line (8) and the pump (10), wherein the amount of fresh water designed solely for wetting the pump (10) is less than or equal to 50 ml; - Evaporation of a residual water quantity in the steaming system (2) downstream of the pump (10) by means of the steam generator (14) with the shut-off valve (18) open. [2] Method according to claim 1, characterized by that the cleaning acid is citric acid and / or the fresh water is tap water and / or the air is ambient air. [3] Method according to claim 1 or 2, characterized by , that the circulation of the cleaning acid is carried out solely by means of the steam generator (14), or the circulation of the cleaning acid takes place solely by means of the steam generator (14) and the steam generator (14) is operated with short heating pulses in such a way that a thermal circulation of the cleaning acid takes place. [4] Method according to one of claims 1 to 3, characterized by , that the predetermined amount of fresh water to wet the pump (10) is less than or equal to 40 ml or is less than or equal to 30 ml. [5] Humidification system (2) for a cooking appliance with a cooking chamber (4), characterized by that the humidification system (2) is designed to carry out the method according to one of claims 1 to 4. [6] Humidification system (2) according to claim 5, characterized by that the humidification system (2) comprises the following components in the specified arrangement: a tank (6), a filling line (8) connected to the tank (6) in a flow-conducting manner and having a pump (10) for filling the tank (6) with a fluid, a steam generator (14) connected to the tank (6) by means of a connecting line (12), an overflow line (16) with a shut-off valve (18) for the flow-conducting connection of the tank (6) with the cooking chamber (4) and a bypass line (20) connected in a flow-conducting manner to the tank (6), to the steam generator (14) and to the overflow line (16) for the flow-conducting connection to the cooking chamber (4) of the cooking appliance. [7] Humidification system (2) according to claim 6, characterized by , that the filling line (8) with the pump (10) is connected to the tank (6) in a flow-conducting manner at an upper side of the tank (6) and / or the steam generator (14) is connected in a flow-conducting manner to the tank (6) on the one hand at a position directly adjacent to the top of one side of the tank (6) and on the other hand at a bottom of the tank (6) and / or the overflow line (16) at the top of the tank (6) is connected to the tank (6) in a flow-conducting manner and / or the bypass line (20) is connected to the tank (6) at the bottom in a flow-conducting manner. [8] Humidification system (2) according to claim 6 or 7, characterized bythat the shut-off valve (18) is designed as a pinch valve. [9] Cooking appliance with a cooking chamber (4) and with a steaming system (2) for steaming the cooking chamber (4) with steam, characterized by that the humidification system (2) is designed according to one of claims 5 to 8.

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