Method for reducing the temperature of wastewater from a cooking appliance and cooking appliance

Abstract

A method for reducing the temperature of wastewater from a cooking appliance (10) is described, wherein the temperature in the cooking chamber (12) and / or the temperature in the steam generator (14) is determined by a temperature sensor located in the cooking chamber (12) and / or in the steam generator (14) and / or in a control box (30), the determined temperature is compared with a temperature limit, and if the determined temperature in the cooking chamber (12) during cleaning and / or the determined temperature in the steam generator (14) immediately before emptying the steam generator (14) exceeds the temperature limit, fresh water is supplied to the steam generator (14), the cooking chamber (12), the control box (30) and / or a cleaning box (34) of the cooking appliance (10) via a fresh water connection (15) of the cooking appliance (10). A cooking appliance (10) is also described.

Description

[0001] The invention relates to a method for reducing a temperature of waste water from a cooking appliance and to a cooking appliance.

[0002] Cooking appliances, especially combi steamers, typically include a drain line for removing wastewater from the cooking appliance. Wastewater is generated, for example, during a cleaning process, when draining water from a steam generator, when extinguishing steam in a control box, or when emptying a cleaning box.

[0003] The term “control box” refers to a collecting container for the precipitation of steam.

[0004] A cleaning box is a collection container for forming a washing solution.

[0005] In the cases mentioned, the wastewater may have a high temperature.

[0006] The sewage system is therefore also exposed to thermal influences.

[0007] Wastewater cooling systems are known, which monitor the temperature in a wastewater system and supply cold water to the system as needed. However, these systems are complex and expensive.

[0008] It is an object of the present invention to ensure in a simple and cost-effective manner that the wastewater temperature does not exceed a predetermined temperature limit.

[0009] This object is achieved according to the invention by a method for reducing the temperature of wastewater from a cooking appliance. In one method step, the temperature in the cooking chamber and / or the temperature in the steam generator is determined using a temperature sensor arranged in the cooking chamber and / or in the steam generator and / or in a control box. The determined temperature is compared with a temperature limit value. If the determined temperature in the cooking chamber during cleaning and / or the determined temperature in the steam generator immediately before emptying the steam generator exceeds the temperature limit value, fresh water is supplied to the steam generator, the cooking chamber, the control box and / or a cleaning box of the cooking appliance via a fresh water connection of the cooking appliance.

[0010] The fresh water, which is provided in particular at a building-side water connection, has a relatively low temperature, for example a temperature of 10 °C to 20 °C. By supplying fresh water to the steam generator, the cooking chamber, a control box and / or the cleaning box of the cooking appliance, the wastewater to be discharged from the cooking appliance is mixed with the fresh water, whereby the temperature of the wastewater is reduced to below the temperature limit T G can be lowered.

[0011] By determining the temperature in the cooking chamber and / or steam generator before the waste water is discharged from the cooking appliance, it is ensured that fresh water is only added when the temperature limit is actually exceeded, so that fresh water is not added unnecessarily for cooling when this is not necessary.

[0012] The steam generator may comprise a water boiler in which a supply of water can be brought to the boil, and an overflow tank, wherein the fresh water supply is, for example, carried out into the overflow tank.

[0013] The temperature in the cooking chamber can be determined directly by a temperature sensor located in the cooking chamber or indirectly by a temperature sensor located outside the cooking chamber.

[0014] In particular, the temperature sensors already present in a cooking appliance are used to carry out the process.

[0015] The temperature determined is in particular a water temperature, more precisely the temperature of a washing liquor.

[0016] Based on the measured temperature in the steam generator and the steam generator volume, the volume of fresh water required for cooling can be calculated. This fresh water is mixed with the wastewater from the steam generator to reduce the wastewater temperature to at least the temperature limit. By calculating the volume of fresh water required for cooling, unnecessary water consumption is avoided.

[0017] According to one embodiment, the fresh water is fed to the steam generator while the steam generator is being drained by a drain pump. During the draining process, the water is mixed to ensure a uniform temperature before the wastewater enters the sewage system.

[0018] Alternatively, fresh water can be added to the control box via a flushing nozzle and / or a control nozzle, while the steam generator is drained using a drain pump, so that the fresh water mixes with the wastewater from the steam generator in the drain line, the control box, and / or the cleaning box. This also ensures thorough mixing of the wastewater.

[0019] When cleaning the cooking appliance, for example, the temperature of the wash liquor is measured, and if the temperature limit is exceeded, fresh water is added to the cooking chamber before the end of the circulation phase. This addition during the circulation phase ensures thorough mixing, ensuring the wastewater has a consistent temperature.

[0020] However, the addition of fresh water is preferably only carried out towards the end of the cleaning process to avoid reducing the temperature of the wash liquor during cleaning and thus negatively impacting the cleaning effect. For example, the addition of fresh water takes place in the last tenth of the cleaning process.

[0021] Alternatively, the fresh water supply can take place when the washing solution is pumped out, so that the water mixes in the drain line, the control box and / or the cleaning box.

[0022] When cooling the wash liquor, a necessary fresh water volume is also calculated, preferably based on the volume of the cooking chamber and the determined temperature of the wash liquor, in order to cool the wash liquor to a temperature below the temperature limit.

[0023] It is also conceivable that the temperature of the wash liquor is monitored during the supply of fresh water and the fresh water supply is stopped when the temperature of the wash liquor has reached the temperature limit.

[0024] If the cleaning box of the cooking appliance is emptied, a volume of fresh water that is at least equal to the volume of the cleaning box is fed into the cleaning box before the cleaning box is emptied. There is usually no temperature sensor in the cleaning box, so the wastewater temperature in the cleaning box cannot be determined. However, by supplying a volume of fresh water that is at least equal to the volume of the cleaning box, it is ensured that the temperature of the wastewater from the cleaning box does not exceed the temperature limit. Since the volume of the cleaning box is relatively small, for example 2.5 liters, the freshwater consumption in this case is relatively low, so it is justifiable to supply fresh water even if the temperature in the cleaning box does not exceed the temperature limit at all. This means that an additional temperature sensor is not necessary.

[0025] The temperature limit is preferably a maximum of 65°C, especially 60°C. This temperature ensures that the wastewater discharged from the cooking appliance does not have any negative thermal impact on the wastewater system.

[0026] Preferably, the temperature limit can be individually adjusted. This allows for response to specific requirements, especially different regional regulations.

[0027] The object is further achieved according to the invention by a cooking appliance having a cooking chamber, a fresh water connection and a steam generator, wherein the cooking appliance comprises at least one temperature sensor for determining the temperature in the cooking chamber and / or in the steam generator, and wherein the cooking appliance comprises a control unit which is configured to detect the temperature measured by the at least one temperature sensor and to compare it with a temperature limit value and to control a fresh water supply for cooling the waste water according to the method according to the invention.

[0028] By means of the cooking appliance according to the invention, the same advantages can be achieved as already described in connection with the method according to the invention.

[0029] The at least one temperature sensor for determining the temperature in the cooking chamber and / or the steam generator can be located in the cooking chamber or steam generator or outside the cooking chamber or steam generator, for example, in the drain line or in the control box. The temperature in the cooking chamber or steam generator can therefore be determined directly or indirectly, as already mentioned in connection with the method.

[0030] Further advantages and features of the invention will become apparent from the following description and from the accompanying single drawing, to which reference is made.

[0031] Fig. 1 shows a cooking appliance 10 according to the invention, which is, for example, a combi steamer.

[0032] The cooking appliance 10 has a cooking chamber 12 and a steam generator 14 and a fresh water connection 15.

[0033] The steam generator 14 comprises a water boiler 16 in which a water supply can be brought to a boil, so that steam is produced, which can be supplied to the cooking chamber 12 via a steam outlet 18.

[0034] In addition, the steam generator 14 comprises an overflow tank 20 which is fluidly connected to the water boiler 16 such that the same fill level is established in the overflow tank 20 as in the water boiler 16.

[0035] In the exemplary embodiment, a fresh water inlet 22 starting from the fresh water connection 15 flows into the overflow tank 20, so that fresh water can be supplied to the steam generator 14 via the overflow tank 20.

[0036] However, it is also conceivable that the fresh water inlet 22 flows directly into the water tank 16.

[0037] Starting from the overflow tank 20, a drain line 24 runs to a waste water outlet 26 of the cooking appliance 10.

[0038] The steam generator 14 is emptied via the overflow tank 20. A drain pump 28 is provided for this purpose.

[0039] The drain pump 28 is arranged at an outlet of the water boiler 16 to the overflow tank 20.

[0040] Furthermore, the cooking appliance 10 comprises a control box 30.

[0041] An outlet opening 32 is provided in a floor of the cooking chamber 12, which leads to the control box 30.

[0042] The control box 30 serves to condense steam from the cooking chamber 12. For this purpose, a control nozzle 33 is arranged in the control box 30, through which fresh water can be atomized.

[0043] Furthermore, the control box 30 may have a rinsing nozzle 35 which serves to supply fresh water to the control box 30 for cleaning purposes.

[0044] The control nozzle 33 and the flushing nozzle 35 are connected in particular to the fresh water connection 15.

[0045] Furthermore, the cooking appliance 10 comprises a cleaning box 34.

[0046] The cleaning box 34 is connected to the control box 30.

[0047] The cleaning box 34 can collect the condensate from the control box 30 and / or dirty water from cleaning the cooking chamber 12. In the cleaning box 34, the collected liquid is separated from contaminants, such as grease. Any wastewater to be discharged can then be pumped out via a wastewater pump (not shown).

[0048] The control box 30 and the cleaning box 34 are fluidically connected via a nozzle 36.

[0049] Both the control box 30 and the cleaning box 34 are arranged in the course of the drain line 24, i.e. the wastewater flowing to the wastewater outlet 26 passes through the control box 30 and the cleaning box 34.

[0050] A humidification nozzle 38 is arranged in the cooking chamber 12, which is also connected to the fresh water connection 15.

[0051] A valve 40 is arranged between the fresh water inlet 22, the control nozzle 33, the rinsing nozzle 35 and the humidification nozzle 38 and the fresh water connection 15 in order to control a fresh water supply.

[0052] Several temperature sensors 42, 44, 46, 48, 50 are provided in the cooking appliance 10, in particular in the steam generator 14, in the water boiler 16 as well as in the overflow container 20, in the cooking chamber 12 and in the control box 30. Additional temperature sensors may be provided optionally.

[0053] In addition, the cooking appliance 10 has a control unit 52 which is configured to detect the temperature measured by the temperature sensors 42, 44, 46, 48, 50.

[0054] Furthermore, the control unit 52 is configured to control the valves 40 in order to regulate a fresh water supply.

[0055] During regular operation of the cooking appliance 10, the temperature sensors 42, 44, 46, 48, 50 serve, for example, to monitor a cooking chamber temperature or a temperature of the water in the steam generator 14, in particular to ensure a desired cooking temperature.

[0056] According to the invention, the temperature sensors 42, 44, 46, 48, 50 can also be used to monitor a wastewater temperature.

[0057] In particular, it is desired that a temperature of the waste water, which arises, for example, when emptying the steam generator 14 or when discharging a washing liquor after cleaning the cooking chamber 12, does not exceed a temperature limit value.

[0058] For example, the temperature limit is a maximum of 65°C, especially 60°C.

[0059] The temperature limit value is stored in the control unit 52 and can preferably be individually adjusted.

[0060] If the steam generator 14 is to be emptied, for example for cleaning purposes, the temperature in the steam generator 14 is first determined, in particular with the temperature sensors 42, 44 arranged in the water boiler 16 and in the overflow tank 20.

[0061] The measured temperature in the steam generator 14 is then compared with the temperature limit. This is done by the control unit 52.

[0062] If the determined temperature in the steam generator 14 immediately before the steam generator 14 is emptied exceeds the temperature limit value, fresh water is fed into the steam generator 14 via the fresh water connection 15 of the cooking appliance.

[0063] Based on the measured temperature in the steam generator 14 and the volume of the steam generator 14, a volume of fresh water required for cooling is calculated, which is mixed with the wastewater from the steam generator 14 in order to reduce the temperature of the wastewater at least to the temperature limit value.

[0064] The volume of the steam generator corresponds to the volume of the water boiler 16 and the volume of the overflow tank 20 together.

[0065] In order to achieve good mixing, the fresh water is fed to the steam generator 14, while the steam generator 14 is emptied by means of a drain pump 28.

[0066] Alternatively, the fresh water can be supplied to the control box 30, in particular via the control nozzle 33 and / or the rinsing nozzle 35, while the steam generator 14 is emptied by the drain pump 28. As a result, the fresh water mixes with the wastewater from the steam generator 14 in the drain line 24, in the control box 30, and / or in the cleaning box 34, so that the wastewater temperature at the wastewater outlet 26 of the cooking appliance 10 is below the temperature limit.

[0067] When the cooking chamber 12 is cleaned, the temperature in the cooking chamber 12, i.e., the temperature of the wash liquor, is determined. If the temperature in the cooking chamber 12 exceeds the temperature limit during cleaning, fresh water is also added.

[0068] Preferably, the fresh water is fed into the cooking chamber 12 before the end of the circulation phase so that the waste water is particularly well mixed.

[0069] The fresh water is supplied to the cooking chamber 12, for example, via the humidification nozzle 38.

[0070] Alternatively, when draining the wash liquor, it is also possible for the fresh water to be fed into the control box 30, in the same way as when emptying the steam generator 14.

[0071] If the cleaning box 34 is to be emptied, a fresh water volume that corresponds at least to the volume of the cleaning box 34 is supplied to the cleaning box 34 before emptying.

Claims

[1] A method for reducing a temperature of waste water from a cooking appliance (10), the method comprising the following steps: a) determining the temperature in the cooking chamber (12) and / or the temperature in the steam generator (14) with a temperature sensor arranged in the cooking chamber (12) and / or in the steam generator (14) and / or in a control box (30), b) comparing the determined temperature with a temperature limit value, c) if the temperature determined in the cooking chamber (12) during cleaning and / or the temperature determined in the steam generator (14) immediately before emptying the steam generator (14) exceeds the temperature limit value, supplying fresh water via a fresh water connection (15) of the cooking appliance (10) into the steam generator (14), the cooking chamber (12), the control box (30) and / or a cleaning box (34) of the cooking appliance (10). [2] Method according to claim 1, characterized bythat, based on the measured temperature in the steam generator (14) and the volume of the steam generator (14), a volume of fresh water required for cooling is calculated, which is mixed with the waste water from the steam generator (14) in order to reduce the temperature of the waste water at least to the temperature limit value. [3] Method according to one of claims 1 or 2, characterized in that the fresh water is supplied to the steam generator (14) while the steam generator (14) is emptied by means of a drain pump (28). [4] Method according to one of claims 1 or 2, characterized by that the fresh water is added to the control box (30) via a rinsing nozzle (35) and / or a control nozzle (33), while the steam generator (14) is emptied by means of a drain pump (28), so that the fresh water mixes with the waste water from the steam generator (14) in the drain line (24), in the control box (30) and / or in the cleaning box (34). [5] Method according to one of the preceding claims, characterized by that when cleaning the cooking appliance (10) the temperature of the washing liquor is determined and if the temperature limit is exceeded, fresh water is supplied to the cooking chamber (12) before the end of the circulation phase. [6] Method according to one of the preceding claims, characterized by that before emptying the cleaning box (34) a fresh water volume which corresponds at least to the volume of the cleaning box (34) is supplied to the cleaning box (34). [7] Method according to one of the preceding claims, characterized by that the temperature limit is a maximum of 65°C, especially 60°C. [8] Method according to one of the preceding claims, characterized by that the temperature limit can be individually adjusted. [9] Cooking appliance (10) with a cooking chamber (12), a fresh water connection (15) and a steam generator (14), wherein the cooking appliance (10) comprises at least one temperature sensor (42, 44, 46, 48, 50) for determining the temperature in the cooking chamber (12) and / or in the steam generator (14), and wherein the cooking appliance comprises a control unit (52) which is designed to detect the temperature measured by the at least one temperature sensor (42, 44, 46, 48, 50) and to compare it with a temperature limit value and to control a fresh water supply for cooling the waste water according to a method according to one of the preceding claims.

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