Cleaning chemical assembly for a cooking appliance and cooking appliance with such an assembly

Abstract

Cleaning chemical assembly (22) for a cooking appliance (10), comprising a collection container (24), a distributor (26) to which fluid can be supplied from the collection container (24) and which has at least one outlet to a cleaning chemical container (28) and one outlet to a circulation circuit of the cooking appliance (10), wherein the distributor (26) is arranged above the collection container (24), characterized in that the distributor (26) has a bypass (38) through which fluid can enter the collection container (24) directly.

Description

[0001] The invention relates to a cleaning chemical assembly for a cooking appliance, comprising a collection container, a distributor to which fluid can be supplied from the collection container, and which has at least one outlet to a cleaning chemical container and one outlet to a circulation circuit of the cooking appliance, wherein the distributor is arranged above the collection container. The invention also relates to a cooking appliance with such a cleaning chemical assembly.

[0002] The cooking appliance according to the invention is designed for professional use, i.e., in restaurants, canteens, and large-scale catering establishments. Such cooking appliances can be cleaned using an automatically running cleaning program. For this purpose, the cooking appliance is equipped with a supply of cleaning chemicals from which a cleaning fluid can be produced. This fluid then circulates within the cooking appliance to achieve the desired cleaning effect. For example, a cooking chamber of the appliance can be cleaned and / or descaled, or a steam generator can be descaled.

[0003] The cleaning fluid is produced by a cleaning chemical assembly, which includes a collection tank, a distributor, and usually several cleaning chemical containers, also referred to as reservoirs. A pump draws water into specific reservoirs, dissolving some of the cleaning chemicals. These then flow into the collection tank, where the fluid is drawn back in and pumped to the reservoirs. Once the cleaning fluid in the collection tank has the desired concentration of cleaning chemicals, it can be pumped either to a recirculation circuit within the cooking appliance for cleaning or descaling the cooking chamber, or to a steam generator for descaling.

[0004] Regarding the details of such a cleaning chemical assembly, reference is made to DE 10 2020 117 842 A1, which is fully referenced with regard to the design and operation of the cleaning chemical assembly.

[0005] Another cleaning device for cooking appliances is known from DE 10 2015 109 019 A1.

[0006] Further dosing devices for cleaning agents are known from DE 10 2014 202 430 A1 and WO 2006 / 037 354 A1.

[0007] It has been found that air pockets can form within the cleaning chemical assembly. These air pockets can impair the assembly's function by preventing the equalization of communicating water columns, thus preventing relevant areas from being flooded, or by preventing the pump from removing the fluid or allowing the fluid to flow freely because the trapped air cannot be displaced. Furthermore, it has been found that air pockets can act like undesirable cross-sectional constrictions if they are not carried away by the flow.

[0008] The object of the invention is to improve the known cleaning chemical assembly in such a way that there are no impairments caused by air inclusions.

[0009] To solve this problem, a cleaning chemical assembly of the type mentioned above is designed with a distributor that has a bypass through which fluid can flow directly into the collection tank. The bypass allows air and / or liquid trapped in the distributor to flow into the collection tank, thus preventing unwanted air pockets in the distributor. This also reduces resistance when the pump starts up.

[0010] According to one embodiment of the invention, the bypass has a permanently open outlet leading from the distributor to the collection tank. This creates a slight leakage back into the collection tank, i.e., to the pump's intake area. This leakage is designed to be so small that the hydraulic efficiency during circulation or discharge is not significantly impaired. If air should be trapped in the distributor, the remaining water and air can escape through the leakage, thus preventing back pressure when the pump starts.Even if the distributor does not empty itself due to the small cross-section of the leak and the effect of surface tension, the back pressure is still significantly lower than that which would have to be overcome if the cleaning fluid were pumped through the outlet to a circulation loop of the cooking appliance, where a siphon is usually present. The particular advantage of this design is that it is a technically very simple solution without moving parts. The permanently open drain is alternately flushed with acid, alkali, and water, so that any dirt and limescale deposits are removed, thus keeping the drain permanently clear.

[0011] Preferably, the bypass has a flow cross-section that is no more than 20% of the cross-section of the distributor's inlet, preferably on the order of 5 to 10%. This ensures that the bypass impairs the effectiveness of the cleaning chemical assembly to an extent that is negligible for its technical function, since the loss through the bypass is only a small fraction of the fluid flow delivered by the pump.

[0012] According to an alternative embodiment of the invention, the bypass has a second outlet leading from the distributor to the collection tank and is located above the first outlet. Here, too, the combined cross-section of both outlets is so small that it is negligible compared to the pump's delivery capacity with regard to the operation of the cleaning chemical assembly. The upper outlet ensures that the distributor is self-draining, since when the pump is not running, air can be drawn into the distributor through the upper outlet, while water remaining in the distributor drains out through the lower outlet. Furthermore, the residual volume does not need to be drained first to vent the distributor, as the air can escape directly through the upper outlet. When the pump is running, both outlets are flushed, thus keeping them clear at all times.

[0013] Preferably, the second outlet has a smaller cross-section than the first. This is possible because the primary purpose of the second outlet is to draw in only air, so the effects of water surface tension need not be taken into account. The small cross-section does not impair the hydraulic effectiveness of the entire system.

[0014] According to a further embodiment of the invention, the bypass has a drain leading from the distributor to the collection tank, with a valve associated with the drain that is open in the resting state and closes when there is overpressure in the distributor. This embodiment has the advantage that the cross-section of the drain can be made significantly larger, so that the distributor empties itself when the pump is not running. The valve ensures that the hydraulic effectiveness of the cleaning chemical assembly is not impaired, since it closes when the pump is running due to the resulting overpressure.

[0015] It is also conceivable that the pump, which pumps fluid from the collection tank to the distributor, is equipped with a vent. In the case of a pump, which is typically a centrifugal pump, this vent can be located in an area between the central intake area, where there is negative pressure, and a more distant area, where there is positive pressure. This allows venting without significantly affecting the pump's hydraulic performance. The vent allows air to escape from the pump, which would otherwise accumulate inside because it cannot circulate further into the hydraulic system. The vent ensures that the pump operates at a higher pressure, making it much easier to expel any air that may be trapped in the rest of the hydraulic system.

[0016] The invention is explained below with reference to the accompanying drawings. These show: - Fig. 1 schematically a cooking appliance with a cleaning chemical assembly according to a first embodiment; - Fig. 2 a cross-section through the cleaning chemical assembly of Fig. 1; - Fig. 3 a longitudinal section along plane III-III of Fig. 1; - Fig. 4 a schematic representation of a cleaning chemical assembly according to a second embodiment; - Fig. 5 a schematic representation of a cleaning chemical assembly according to a third embodiment.

[0017] In Fig. Figure 1 schematically shows a cooking appliance 10, which is used to cook food or dishes. The cooking appliance 10 is a device intended for professional use in restaurants, canteens, or large-scale catering establishments.

[0018] The cooking appliance 10 has a cooking chamber 12 into which the food to be cooked can be placed. There, it can be cooked in a cooking chamber atmosphere that is dry air, air with a controllable humidity level, or steam. It is also possible to introduce microwave radiation into the cooking chamber 10. The necessary components for this, such as a steam generator, heating element, circulation device, or microwave generator, are included in Fig. 1 not shown, as they are not necessary for understanding the invention.

[0019] Below the cooking chamber 12 is a cleaning box 14, which is connected to the floor of the cooking chamber 12 by a drain opening 16. Liquids, cooking residues, cleaning fluid (the so-called washing solution), etc., flow from the cooking chamber 12 into the cleaning box 14 through the drain opening 16.

[0020] The contents of the cleaning box 14 can be pumped (not shown) to a wastewater outlet 18 when the cleaning box 14 needs to be emptied. Alternatively, the contents of the cleaning box 14 can be pumped into the cooking chamber 12 via a circulation pump 20, from where they return to the cleaning box 14. This circulation is used to clean the cooking chamber by circulating a cleaning fluid through the chamber 12 until it is clean.

[0021] For safety reasons, a free overflow is also provided, but it is not visible here.

[0022] A cleaning chemical assembly 22 is provided to supply the cleaning fluid. For details of the assembly, full reference is made to the contents of DE 10 2020 117 842 A1.

[0023] In general terms, the cleaning chemical assembly 22 comprises a collection container 24, a distributor 26, and several cleaning chemical containers 28, which are hereinafter referred to as storage containers 28. Water can be supplied via a fresh water connection 29.

[0024] A pump 30 can spray water from the collection tank 24 into the storage tanks 28, causing some of the cleaning chemicals contained therein to dissolve and flow into the collection tank 24. This process of rinsing the cleaning chemicals from the storage tanks 28 continues until the desired concentration of cleaning chemicals is reached in the collection tank 24. The water level remaining in the distributor 26 and the collection tank 24 when the pump 30 is switched off is designated here with reference numeral 41.

[0025] The cleaning chemical, once prepared at the desired concentration, can be pumped into the cleaning box via line 32 if it is a cleaning fluid, or to a steam generator via line 34 if it is a descaling fluid.

[0026] The function of the distributor 26 is to direct the fluid supplied by the pump 30 either to one or more of the storage containers 28 for cleaning chemicals or to open the outlets to the lines 32, 34 by means of various valves.

[0027] The corresponding valves are in the Fig. 2 and Fig. 3 with the reference number 36.

[0028] The distributor 26 is provided with a bypass 38, which, generally speaking, is a hydraulic connection from the inside of the distributor 26 to the inside of the collection tank 24.

[0029] At the in Fig. In the embodiment shown in Figure 1, the bypass 38 is designed as a permanently open drain 40, which leads from the distributor 26 to the collection container 24.

[0030] The bypass 38 provides a minor leakage from the interior of the distributor 26, allowing any trapped water or air to be discharged into the collection tank 24. The cross-section of the bypass 38 is chosen to be so small that the leakage is negligible compared to the flow rate of the pump 30. Specifically, the cross-section of the bypass 38 is on the order of 5 to 10% of the narrowest cross-section of the inlet line 42 shown schematically here, which leads from the pump 30 to the distributor 26.

[0031] In Fig. Figure 4 shows a second embodiment. The same reference numerals are used for the components known from the first embodiment, and reference is made to the explanations above.

[0032] The difference between the first and second embodiments is that in the second embodiment, the bypass 38 additionally has a second outlet 44, which connects the interior of the distributor 26 with the interior of the collection container 24. The second outlet 44 is connected to the distributor 26 above the first outlet 40.

[0033] The second outlet 44 serves primarily to allow air exchange between the collection tank 24 and the distributor 26. This facilitates the drainage of any water remaining in the distributor 26 after shutdown into the collection tank 24 via the first outlet 40. Accordingly, the second outlet 44 can have a smaller cross-section than the first outlet 40.

[0034] The particular advantage of both the first and second embodiments is that, during operation of the pump 30, the first drain 40 and, if present, also the second drain 44 are initially flushed with water and then, depending on the cleaning chemical used, with acid or alkali. This reliably flushes away any deposits, preventing the drains 40 and 44 from becoming clogged even after extended periods of operation. Furthermore, the absence of moving parts positively impacts durability.

[0035] In Fig. Figure 5 shows a third embodiment. The same reference numerals are used for the components known from the previous embodiments, and reference is made to the explanations above in this respect.

[0036] The third embodiment is based on the first embodiment insofar as the bypass 38 has a single outlet 40. Unlike the first embodiment, the outlet 40 is not permanently open; instead, a valve 50 is provided that can close the outlet 40 depending on the pressure. The valve 50 has a valve element that is acted upon by a spring to an open position. When the pressure inside the distributor 26 increases during operation of the pump 30, the valve 50 closes, thus closing the outlet 40. This has the advantage of reducing unwanted leakage and thus a reduction in pump performance during operation of the pump 30.

[0037] When pump 30 is switched off, valve 50 reopens, and any liquid remaining in distributor 26 can drain through drain 40 into collection tank 24. Drain 40 is thereby flushed.

Claims

[1] Cleaning chemical assembly (22) for a cooking appliance (10), comprising a collection container (24), a distributor (26) to which fluid can be supplied from the collection container (24) and which has at least one outlet to a cleaning chemical container (28) and one outlet to a circulation circuit of the cooking appliance (10), wherein the distributor (26) is arranged above the collection container (24), characterized by , that the distributor (26) has a bypass (38) through which fluid can pass directly into the collection tank (24). [2] Cleaning chemical assembly (22) according to claim 1, characterized by , that the bypass (38) has a permanently open outlet (40) that leads from the distributor (26) to the collection tank (24). [3] Cleaning chemical assembly (22) according to claim 2, characterized by , that the bypass (38) has a flow cross-section which is no more than 20% of the cross-section of an inlet (42) of the distributor (26). [4] Cleaning chemical assembly (22) according to claim 2 or claim 3, characterized by , that the bypass (38) has a second outlet (44) which leads from the distributor (26) to the collection tank (24) and is located above the first outlet (40). [5] Cleaning chemical assembly (22) according to claim 4, characterized by , that the second drain (44) has a smaller cross-section than the first drain (40). [6] Cleaning chemical assembly (22) according to claim 1, characterized by , that the bypass (38) has a drain (40) which leads from the distributor (26) to the collection tank (24), wherein the drain (40) is associated with a valve (50) which is open in the rest state and closes when there is overpressure in the distributor (26). [7] Cleaning chemical assembly (22) according to claim 6, characterized by , that the bypass (38) has a flow cross-section which is no more than 50% of the cross-section of an inlet (42) of the distributor (26). [8] Cooking appliance (10) with a cleaning chemical assembly (22) according to one of the preceding claims, wherein the cooking appliance (10) has a cooking chamber (12) below which a cleaning box (14) is arranged, wherein a line (32) is connected to the outlet of the distributor (26) to the circulation circuit of the cooking appliance (10), which leads to the cleaning box (14).

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