Cooking appliance for a large-scale kitchen with a fat extraction device, and method for operating such a cooking appliance with fat extraction

Abstract

The present invention relates to a cooking appliance for a large-scale kitchen in the form of a combi-steamer (1, 1'), having a cooking compartment (3) for cooking food which is to be cooked, which can be arranged on a plurality of cooking levels (32), or a rotisserie appliance, having a cooking compartment for cooking food which is to be cooked, which can be arranged on a rotatable carrier, having a heating device for heating the cooking compartment atmosphere, an appliance controller for controlling the cooking appliance, and a cooking compartment drain (33) which is located below a floor (4) of the cooking compartment (3) and serves for conducting away a fat / water mixture and gaseous portions of the cooking compartment atmosphere out of the cooking compartment (3), wherein the cooking compartment drain (33) extends from an outlet opening (15) in the floor (4) or in the floor region of the cooking compartment (3) as far as a siphon device (35), wherein a fat-collecting device (59) is provided which comprises at least one fat-collecting container (61), at least one fat extraction line (73), at least one extraction pump (77) and at least one fat discharge line (82), wherein the fat extraction line (53) extends from the fat-collecting container (61) to the extraction pump (77), wherein the extraction pump (77) is configured to further convey the fat / water mixture sucked up via the fat extraction line (73) into the fat discharge line (82), and wherein a cleaning device is provided which is configured to convey water at least via the fat extraction line (73) and the fat-collecting container (61) into the cooking compartment drain (33) in the direction of the siphon device (35).

Description

[0001] The present invention relates to a cooking appliance for commercial kitchens in the form of a combi steamer or a rotisserie appliance with a grease extraction device.

[0002] Commercial kitchen equipment can have large or very large cooking chambers suitable for accommodating large quantities of food. When cooking fatty foods such as chickens, ducks, geese, etc., a relatively large amount of fat is released. This fat, which escapes along with any liquid present in the food, especially water, forms what is known as steam when it is vented from the cooking chamber, together with the extracted gaseous atmosphere. This steam is then released from the cooking chamber via a vent for disposal.

[0003] In state-of-the-art appliances, the hot steam from the cooking chamber is fed into a siphon with steam condensation. This condenses the steam and cools it along with the fat-water mixture in the steam. Cooling to a predetermined temperature is necessary because only liquids with a maximum temperature, which is generally lower than that of the steam released from the cooking chamber, are permitted to enter the wastewater system of the building's sewer connection.

[0004] From EP 1 717 518 B1, a cooking appliance is known with a cooking chamber drain and a siphon device containing a water reservoir that serves to prevent odors or vapors from the wastewater system from entering the cooking chamber. The water reservoir also serves to cool the hot steam.

[0005] Further relevant prior art is known from documents US 2018 / 224129 A1, EP 2 229 852 A1, DE 10 2012 221857 A1 and DE 10 2006 031581 A1.

[0006] Certain foods, such as those mentioned above, are cooked using a method that produces a large amount of fat, which can cause problems with disposal via the household sewer system. Furthermore, this natural fat is suitable for further processing, for example in the production of cosmetics (e.g., soap) or fuel, thus contributing to the sustainability of such raw material processing.

[0007] A cooking appliance is known from US Patent 8,997,730 B2, which allows for fat recovery by means of fat extraction. In this cooking appliance, the cooking steam is drained through a drain opening and a short pipe stub into a siphon below, which contains a water reservoir. A steam collection container is located below the drain opening, separated from the water reservoir. This collection container has a drain opening connected to a grease extraction line, through which the fat-water mixture can be drawn by a suction pump to a collection container.

[0008] After each cooking process, or after several cooking processes, the cooking chamber must be cleaned for hygiene reasons. This can be done manually by adding a suitable cleaning agent to the cooking chamber, distributing it manually, and then rinsing it out with water. However, automatic cleaning systems have proven particularly advantageous in commercial kitchens. In any case, the cleaning process produces a liquid (powdered or otherwise dissolved) cleaning agent, which, for hygiene reasons, must be completely removed from the cooking chamber and other components of the cooking appliance before another cooking process can be carried out.

[0009] The same elements and components of the cooking appliance are used to dispense the cleaning fluid along with the dissolved cooking residues as those used for steam extraction. With the aforementioned state of the art, this leads to the significant disadvantage that the cleaning agent, mixed with the dissolved residues from the cooking chamber, also enters the steam collection container and is extracted. Consequently, cleaning agent residues enter the collected fat and significantly contaminate this raw material, making it unsuitable for further processing.

[0010] The present invention therefore aims to avoid the disadvantages described above and to propose a cooking appliance for commercial kitchens in the form of a combi steamer or a rotisserie appliance with a fat collection device and fat recovery, which largely prevents cleaning residues from penetrating or mixing with the recovered fat.

[0011] Finally, it is also an object of the present invention to propose a method for operating a commercial kitchen cooking appliance, in particular a combi steamer or a rotisserie appliance with fat recovery, in which contamination of the recovered fat by cleaning agents is largely avoided.

[0012] To solve this problem, the present invention proposes a cooking appliance for commercial kitchens in the form of a combi steamer with a cooking chamber for cooking food, which can be arranged on a plurality of cooking levels, or in the form of a rotisserie appliance, with a cooking chamber for cooking food, which can be arranged on a rotatable cooking carrier, comprising a heating device for heating the cooking chamber atmosphere, a device control for controlling the cooking appliance, and a cooking chamber drain located below a floor of the cooking chamber, which serves to drain a fat-water mixture and gaseous components of the cooking chamber atmosphere from the cooking chamber, wherein the cooking chamber drain extends from a drain opening in the floor or in the floor area of ​​the cooking chamber to a siphon device, wherein a fat collection device is provided, comprising at least one fat collection container, at least one fat extraction line, at least one extraction pump and at least one fat discharge line.wherein the grease extraction line extends from the grease collection container to the extraction pump, wherein the extraction pump is configured to convey the grease-water mixture drawn in via the grease extraction line to the grease discharge line, and wherein a cleaning device is provided which is configured to convey water at least via the grease extraction line and the grease collection container into the cooking chamber drain in the direction of the siphon device.

[0013] This advantageously ensures that cleaning agent residues are flushed out of the grease extraction line and the grease collection container and directed to the siphon system, allowing the resulting grease to be recovered without cleaning agent residues during a subsequent cooking process. This significantly improves the quality of the recovered grease and contributes substantially to its reusability.

[0014] This allows the commercial kitchen operator to obtain a corresponding price for the raw material that can be processed further, which in turn reduces the purchase price of the food being cooked.

[0015] The design, in which the grease collection container is positioned in front of the siphon, specifically between the drain opening and the siphon, offers the significant advantage of considerably reducing the amount of grease entering the siphon from the oven drain. This also significantly reduces the amount of grease in the exhaust duct. As a result, the service life of the oven and its components, such as the siphon drain pump, the cleaning system's circulation pump, seals (especially those of the pumps), the cleaning system's water inlets, and the temperature sensors, can be considerably extended.

[0016] Furthermore, the major advantage over commercial kitchen cooking appliances without fat recovery is retained in that fat separation before draining the cooking chamber into the house drain channel is unnecessary.

[0017] Another advantage is that no changes to existing cooking processes are necessary, and the cooking result is not impaired by the fat collection device according to the invention. The cooking quality is therefore not affected.

[0018] By locating the grease collection container preferably in the initial section of the cooking chamber drain, grease extraction can be carried out early, and the subsequent flow path up to the siphon is cleared of grease early on. For example, an initial section of the grease collection container is arranged within a distance of 80 to 120 mm from the center line of the cooking chamber drain opening, preferably at a distance of 30 to 40 mm from the center line of the drain opening.

[0019] Advantageously, the oven drain and the grease collection container are made of metallic material, which is particularly temperature-resistant, and the grease collection container is welded to the oven drain. This results in a durable connection between the grease collection container and the oven drain, avoiding potentially non-permanent seals, although the connection area is particularly difficult to access due to its installation location below the oven.

[0020] Accordingly, it is also advantageous that the grease extraction line, which may include a grease extraction pipe preferably made of metal, is welded to the grease collection container. This creates a particularly durable connection that is essentially maintenance-free.

[0021] Alternatively, at least the grease collection container, and possibly also the oven drain and / or the grease extraction line, is made of plastic. In this case, the grease collection container can be integrated with the oven drain or attached to it.

[0022] By preferably having a ramped end section of the grease collection container in the direction of the siphon, the advantage of a streamlined design of the grease collection container and its connection to the cooking chamber drain is achieved. The ramped end section of the grease collection container is preferably the section that, in the area of ​​the grease collection container, is located closer to the siphon than to the drain opening, parallel to the longitudinal or central axis of the cooking chamber drain. During backflushing by the cleaning device to clean the grease collection container, the grease collection container is flushed in the direction of the siphon, and the flushed water is directed to the siphon. The ramped design of the end section supports and facilitates the discharge process.

[0023] The ramp-shaped end section is inclined, at least partially, with respect to the longitudinal or central axis of the cooking chamber drain. Various embodiments are possible for the design of the ramp-shaped end section. For example, the end section can be formed from three side surfaces inclined towards each other. Alternatively, the ramp-shaped end section can be conical. In another alternative, the grease collection container can be designed as an inclined and / or conical pipe, or as a pipe section that tapers towards the siphon.

[0024] Advantageously, a branch line for draining gaseous components of the fluid or vapors discharged from the cooking chamber into the cooking chamber drain—i.e., the fat-water mixture and the gaseous components of the cooking chamber atmosphere—branches off from the cooking chamber drain between the grease collection container and the siphon device. This advantageously allows for a lower cooling capacity of the siphon device.

[0025] In this context, it is advantageous that the branch line comprises a first section that runs essentially horizontally with a slight incline of 1° to 5°, preferably 2° to 2.5°. The hot exhaust air from the cooking chamber generally contains fat in the form of fat droplets, and this exhaust air partially condenses in the branch line. The slight incline allows this condensate, possibly containing fat, to flow back into the cooking chamber drain. Therefore, the incline is preferably defined in a flow direction originating from the cooking chamber drain through the branch line.

[0026] Furthermore, it is advantageous that the grease extraction line extends from the grease collection container to the extraction pump at least partially at a slight gradient of 1° to 5°, preferably 1.5° to 2°. This largely prevents the grease-water mixture from flowing back into the grease collection container.

[0027] Furthermore, an advantage can be achieved by arranging the grease extraction line and the first section of the branch line close to each other, preferably adjacent to one another. The advantage of this is that the closer the branch line is to the grease extraction line, the greater the heat transfer from the branch line, heated by the exhaust air, to the grease extraction line. This significantly reduces the solidification of the grease flowing through the extraction line and improves its flowability through the transferred heat. The close distance is therefore preferably chosen to allow heat transfer between the branch line and the grease extraction line. This distance can be in the range of a few centimeters, preferably between 0 cm and 5 cm, more preferably between 0 cm and 3 cm, and even more preferably between 0 cm and 1 cm.A distance of 0 cm corresponds to the embodiment in which the branch line and the grease extraction line are arranged next to each other, as described above.

[0028] Furthermore, it is advantageous that the suction pump is designed as a bidirectional pump, allowing flow to occur against the pumping direction. The suction pump transfers the grease-water mixture from the grease collection container to the grease dispensing line. Particularly if the pump inlet cannot be sealed, cleaning fluid can potentially reach the pump and accumulate there. Because the suction pump is designed to allow flow against the pumping direction, it can be flushed in this direction. This allows any accumulated cleaning fluid residue to be removed.

[0029] In a preferred embodiment of the present invention, the grease discharge line comprises a riser pipe that is arranged at or connected to the pump outlet of the suction pump and extends upwards from there over a certain distance. This offers two advantages: firstly, it limits the ingress of cleaning fluid into the riser pipe up to the level of the drain opening in the cooking chamber of the appliance, and secondly, it allows the extracted grease-water mixture to be conveyed upwards sufficiently to flow into a grease collection container. While in a space-saving design the riser pipe is arranged essentially vertically upwards, inclined arrangements of the riser pipe are also possible within the scope of the invention.

[0030] Advantageously, the cleaning device for cleaning the grease collection system includes a water supply. Cooking appliances, especially combi steamers, typically have a water supply to create steam in the cooking chamber. This is achieved by generating steam within the cooking chamber or by introducing steam from outside. Water is also required for cleaning the cooking chamber, for example, via a hand shower or an automatic cleaning system. In an advantageous embodiment, the water supply of the cooking appliance also serves as the water supply for the cleaning device. However, it is also conceivable that the cleaning device includes a separate water supply or can be connected to an external water source.

[0031] Furthermore, it is advantageous that the water supply to the cleaning device for cleaning the grease collection system has at least one water supply line that opens into the riser pipe above the suction pump. This allows the pipework, including the suction pump, which may be contaminated with cleaning fluid, to be reliably flushed and freed of any remaining cleaning fluid.

[0032] If the suction pump has a closable pump inlet, closing this inlet prevents cleaning fluid from entering the pump. This also advantageously allows the water supply line of the cleaning device to be connected directly before the pump inlet, in order to flush the grease suction line and grease collection container from there.

[0033] Furthermore, it is advantageous that the water supply to the cleaning device for cleaning the grease collection system has at least one additional water supply line. Thus, in addition to the water supply line that leads into the riser pipe, another water supply line can be provided that leads directly into the grease collection container and / or another water supply line can be provided that leads into the grease extraction line directly before the extraction pump.

[0034] The water supply is equipped with at least one valve, in particular a solenoid valve, which controls the supply of fresh water to the at least one water supply line. Several solenoid valves control the water supply to several water supply lines.

[0035] In one embodiment, the suction pump can advantageously be arranged at a height above the level of the drain opening in the base or base area of ​​the cooking chamber of the appliance, with one outlet of the grease suction line being connected to the pump inlet via a connecting line. This has the advantage that cleaning fluid never reaches the suction pump and therefore does not need to be subsequently cleaned. It may therefore be sufficient to at least partially flush the grease collection system upstream of the suction pump, in particular the grease suction line and the grease collection container. However, to remove deposits from the system, it may still be desirable in this embodiment to flush the suction pump and, if necessary, the grease discharge line, as described above.

[0036] Alternatively, the extraction pump can be positioned between the oven floor and the appliance floor, or even below the appliance floor.

[0037] The suction pump is not in operation during the cleaning function of the cooking appliance. This prevents cleaning agent from being drawn into the suction pump.

[0038] The suction pump is also not in operation during the operation of the cleaning device for cleaning the grease collection device, which allows its flushing to take place unhindered, especially if the water supply is located after the suction pump, for example in the riser pipe.

[0039] A further advantage of the present invention is that a heating device is provided on or in the fat collection container, by means of which liquid non-fat components of the fat-water mixture drained from the cooking chamber can be evaporated. This achieves the advantage of further reducing the water content in the fat-water mixture and thus increasing the fat concentration during recovery.

[0040] Furthermore, it is advantageous that the grease collection device has a shut-off valve at the inlet of the water supply, in particular the at least one water supply line, into the grease extraction line, so that after the grease extraction line is shut off, the cleaning device is able to clean the extraction pump and the grease discharge line by flushing. This can be provided in addition to the water supply line that opens into the grease discharge line, in particular into the riser pipe, after the extraction pump, or can be connected to it. The shut-off valve can advantageously be a multi-way valve that can assume one position in which the grease extraction line and the grease collection container are flushed, and another position in which the extraction pump and the grease discharge line are flushed. Optionally, the shut-off valve can also be designed to allow flushing in both directions simultaneously.In this case, it may be sufficient to provide only a single water supply line.

[0041] In one embodiment of the cooking device, the cleaning unit comprises a water supply line connected to the grease discharge line, in particular to a discharge pipe or a shut-off valve of the grease discharge line. This water supply line can also be referred to as a connecting line or hose. In other words, the water supply line can be connected to the end of the grease discharge line that is not connected to the suction pump. The water supply or connecting line can be connected to an external water source, for example, a water pipe or a tap. Preferably, a first end of the water supply or connecting line is connected to the grease discharge line, and a second end of the water supply or connecting line, opposite the first end, can be connected to the external water source. Preferably, the water supply or connecting line is...The connecting pipe, especially its second end, can still be connected to the grease collection container. The grease collection container needs to be changed regularly and is therefore usually easily accessible. This also applies to the second end of the water supply / connecting pipe, which can thus be easily accessed by a user and connected to the water source. This provides a simple way to flush the entire grease collection system.

[0042] With intensive and / or prolonged use of the cooking appliance, there is a risk of grease accumulating in inconvenient areas. It is advantageous to heat the water used for rinsing the cleaning system to clean the grease collection tray, thereby loosening and flushing away any hardened grease.

[0043] The above-mentioned partial problem is also solved by a grease collection device of the cooking appliance according to the invention, which comprises at least one grease collection container, at least one grease extraction line, at least one extraction pump and at least one grease discharge line, wherein the grease collection container can be arranged at a cooking chamber drain of the cooking appliance near a drain opening in the base or in the base area of ​​the cooking appliance, wherein the grease extraction line extends from the grease collection container to the extraction pump, wherein the extraction pump is configured to pump the grease-water mixture drawn in via the grease extraction line into the grease discharge line, and wherein the grease collection device comprises a cleaning device configured to pump water at least via the grease extraction line and the grease collection container into the cooking chamber drain in the direction of a siphon device at the end of the cooking chamber drain of the cooking appliance.

[0044] This makes it possible to integrate a fat collection system into cooking appliances, enabling the recovery of fat or, if necessary, other substances through appropriate extraction.

[0045] Finally, the present invention also includes a method for operating a commercial kitchen cooking appliance, in particular a combi steamer or a rotisserie appliance, and for collecting fat accumulating during the cooking process, comprising the following steps: The grease-water mixture exiting the cooking chamber of the cooking appliance via its drain opening is collected in a grease collection container of a grease collection device, which is attached to a cooking chamber drain of the cooking appliance. The grease-water mixture is then extracted from the grease collection container via at least one grease extraction line by means of a suction pump located at the end of the grease extraction line. The grease-water mixture drawn in by the suction pump is then discharged via a grease discharge line to the grease collection container. Finally, a cleaning process of the grease collection device is carried out after completion of a cleaning process of the cooking appliance by pumping water in the opposite direction to the extraction direction, at least through the grease extraction line and the grease collection container, into the cooking chamber drain towards a siphon device at the end of the cooking chamber drain of the cooking appliance.

[0046] Advantageously, the suction pump operates in a pulsed manner. The pulse rate can be preset or change during the cooking program or process. For example, suction by pumping occurs in a 60-second cycle: 30 seconds of pumping followed by a 30-second pause. Continuous operation is also possible during certain cooking stages. Alternatively, a pulse rate of less than 50% is also possible, meaning the pumping duration is shorter than the pause.

[0047] It is therefore also advantageous that the extraction rate is adjusted depending on the food being cooked and / or the cooking process. This allows the extraction rate to be adapted to the amount of fat produced, for example, due to the type of food being cooked (e.g., duck, goose) and / or the amount of food in the cooking chamber and / or the progress of the cooking process.

[0048] Furthermore, it is advantageous for the cleaning process of the grease collection device to be carried out both at the beginning and at the end of the cooking appliance's cleaning process. Performing the cleaning at the beginning advantageously removes any remaining grease-water mixture before the cleaning agent drawn from the cooking chamber during the appliance's cleaning process enters it, and performing the cleaning at the end removes any remaining cleaning agent.

[0049] Because the grease collection system is rinsed at the beginning of the cleaning process, the grease collection system is flushed with fresh water. After the rinsing process is complete, some of this fresh water remains in the grease collection container, the grease extraction line, the extraction pump, and a section of the riser pipe. When the cleaning process is then initiated, the water present in the grease extraction line makes it difficult for the cleaning agent to penetrate this line.

[0050] During the next grease extraction process, after the grease collection device has been rinsed again, the available fresh water is transported into the grease collection container, and only then is the extracted grease introduced there. Due to the natural separation between grease and water, the water that has accumulated at the bottom of the collection container can then be drained away, leaving behind the separated grease.

[0051] In an advantageous embodiment, the cleaning process of the grease collection device is carried out automatically. For example, the cleaning process of the grease collection system is automatically initiated as soon as the cleaning process of the cooking appliance is to be started, e.g., by corresponding user input, and / or as soon as the cleaning process of the cooking appliance is completed. Automatic execution of the cleaning process of the grease collection device is particularly feasible if the cleaning device is connected to the water supply of the cooking appliance via the water supply line, as described above.

[0052] Additionally or alternatively, during the cleaning process of the grease collection system, water can be pumped through the discharge line, preferably through the entire grease discharge line, the grease extraction line, and the grease collection container into the cooking chamber drain. This is particularly easy to implement if the cleaning system includes the water supply or connecting line, which can be connected to the grease discharge line and a water source, preferably an external water source, as described above.

[0053] Further details, features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. These show: Fig. 1 a perspective view of a cooking appliance in the form of a combi steamer; Fig. 2 another perspective view of the cooking appliance of Fig. 1with the cooking chamber door removed; Fig. 3 a perspective view of a cooking appliance in the form of a large combi steamer with a rack; Fig. 4 a schematic diagram of the structure of an embodiment of the cooking appliance according to the invention in the form of a combi steamer; Fig. 5 a perspective view of the cooking chamber drain and a partial view of the fat collection device according to the invention with fat extraction line; Fig. 6 a view of the rear of the cooking appliance in the form of a combi steamer with fat extraction pump, fat discharge line and water supply for the cleaning device of the fat collection device; and Fig. 7a, 7 a view of the rear of the cooking appliance according to Fig. 6 with a variant of the cleaning device.

[0054] In the figures, identical elements are labelled with the same reference numbers.

[0055] In the Figures 1 and 2A conventional cooking appliance 1 in the form of a combi steamer 3 is shown, which has a cooking chamber 3 for cooking food, which can be closed by a cooking chamber door 5. For operation, the cooking chamber door 5 has a door handle 8. Next to the cooking chamber 3 is the so-called technical compartment 6, in which a drive device for a fan wheel 7, the appliance control unit with display and operating panel 9, and a hand shower 11 with hand shower head 13 are arranged.

[0056] As can be seen, the hand shower head 13 is recessed in a niche-like recess 19 and pops up in the Figs. 1 and 2The hand shower head 13 does not protrude from the front of the cooking appliance 1 in the depicted resting position. Due to the recessed recess 19, the hand shower head 13 is easy to grasp and can be pulled out together with part of a supply line (not shown). The cooking appliance 1 has a water supply to which the hand shower 11 is connected, and water can be injected into the cooking chamber 3 via the hand shower 11, for example, to carry out a manual cleaning process.

[0057] As further from Fig. 2As can be seen, the cooking chamber 3 has a drain opening 15 in the area of ​​its base 4, through which not only the fat-water mixture formed from condensation and the fat released from the food during cooking, but also gaseous cooking chamber atmosphere can escape, which together form the steam defined here, and the cleaning medium or cleaning or washing liquor generated during a cleaning process can be discharged from the cooking chamber 3.

[0058] As shown schematically, an internal temperature sensor 17 of the cooking device 1 is also located on the bottom 4 of the cooking chamber 3, which serves as a core temperature sensor in the illustrated embodiment.

[0059] An exhaust vent 21 is visible on the top of the cooking chamber 1, to which an exhaust pipe leads. This is described in more detail below.

[0060] While in the Figs. 1 and 2A cooking appliance 1 of a relatively small size is shown in Fig. 3 A large-scale cooking appliance 1' is depicted. Through a transparent door panel 20 of the cooking chamber door 5, a (hanging) rack 29 with a plurality of insertion rails 31 is visible. These rails serve to hold a corresponding number of insertion trays or grids, forming the desired number of insertion levels for the respective cooking process, and loaded with the intended food. A corresponding rack 29 is located on the opposite side, and both racks 29 are part of a known tray rack of a tray trolley 23. This tray trolley 23 has a rectangular frame 25, on which a roller 27 is provided at each corner, with at least two of the rollers 27 being rotatable. As shown from Fig. 3The rack 29 clearly has twenty insertion rails 31, which allows for the storage of a large quantity of food on up to twenty insertion levels. The cooking appliance 1' in turn rests on four corner supports 14.

[0061] Advantageously, a drip tray or drip pan (not shown) can be used on the bottommost shelf runners on both sides. This tray has a slightly downward-sloping opening, allowing liquid fat to flow to this opening, which, when the drip tray is in place, is positioned above the drain opening 15. This allows the fat dripping from above to be collected and directed to the drain opening 15, thus significantly reducing the amount of fat that accumulates on the oven floor 4. Consequently, the oven floor 4 does not require such intensive cleaning, making the cleaning process considerably easier.

[0062] If a large quantity of fatty food, such as ducks or geese, is cooked in such a large cooking appliance 1', a correspondingly large quantity of rendered fat is produced.

[0063] In Fig. 4 The diagram schematically depicts the basic structure of the two cooking appliances 1 and 1', whereby the dimensions of the individual components are not to scale but are shown only schematically. Because both cooking appliances are combi steamers, there are multiple rack levels 32 for accommodating the food being cooked. The fan wheel 7 is driven by the drive unit in the form of a motor 12, which circulates the air or cooking chamber atmosphere 22 in the cooking chamber 3.

[0064] The bottom 4 of the cooking chamber 3 has a drain opening 15, to which a cooking chamber drain 33 is connected. This drain extends along the underside of the cooking chamber 3 to a siphon assembly 35, into which it empties. The siphon assembly 35 has a siphon container 36 containing a water reservoir 37. As is known from the prior art, a partition 41 is provided in the siphon container 36, extending into the water reservoir 37. This creates a water seal against the cooking appliance drain 43, which is connected to the house's drainage system. A drain channel 44 from the siphon container 36 opens into this drainage system (not shown).

[0065] A water supply 45 is shown schematically, supplied with fresh water according to arrow 47. This fresh water can be fed into the siphon container 36 via a water supply line 49. A drain pump 51 is provided for emptying the siphon container 36. A drain line 53 is connected to this pump, through which the water reservoir 37 can be pumped into the drain channel 44. After emptying the siphon container 36, fresh water can be fed into the siphon container 36 via a water supply line 49 of the water supply 45 to replenish the water reservoir 37.

[0066] The in Fig. 4The cooking appliance 1, 1', shown schematically, has an automatic cleaning system comprising a supply line 55 through which liquid from the water reservoir 37 can be introduced into the cooking chamber 3 via a circulation pump 57. The water reservoir 37 serves to condense exhaust air, which is fed to the siphon device 35 via the cooking chamber drain 33, with corresponding vapor components also reaching and contaminating the water reservoir 37. Therefore, to carry out the automatic cleaning of the cooking appliance, the water reservoir 37 is emptied by means of the drain pump 51 and fresh water is supplied via the water supply line 49. This can then serve as the starting liquid for the automatic cleaning and can be supplied to the cooking chamber 3, if necessary, several times by means of the circulation pump 57.

[0067] Furthermore, such an automatic cleaning device for a combi steamer is known from the prior art and will therefore not be described further.

[0068] According to the present invention, the cooking appliance 1, 1' has a fat collection device 59 which has a fat collection container 61, which, as shown in Fig. 4 As can be seen, the drain 33 is arranged below the cooking chamber drain and preferably welded to it. A connection opening 71 for a grease extraction pipe, which is part of a grease extraction line 73, is shown in dashed lines. Other connection options that create a permanent connection between the cooking chamber drain 33 and the grease collection container 61 are within the scope of the invention.

[0069] Reference is now made to Fig. 5 , in which a part of the grease collection device 59 is shown in perspective view

[0070] To connect the cooking chamber drain 33 to the cooking chamber 3, the cooking chamber drain 33 has a cooking chamber drain inlet 34 with a connecting flange 38 that can be screwed onto the cooking chamber floor 4. The grease collection container 61, which is welded to the tubular cooking chamber drain 33, is located near the cooking chamber drain inlet 34. As shown from Fig. 5 As can be clearly seen, the grease collection container 61 has a ramp-shaped end section 62. Details of this are described below.

[0071] As from Fig. 4 and 5 As can be seen, the cooking chamber drain 33 ends in a connection opening 58 for connection to the siphon container 36 of the siphon device 35.

[0072] As will continue to emerge from the Fig. 4 and 5As can be seen, between the grease collection container 61 and the connection opening 58 there is an opening 63 for a branch line 64 of the exhaust air from the cooking chamber 3. This opening 63 forms the beginning of the exhaust air branch line 64, which has a first section 65, a second section 67 and a third section designed as a connection spigot 69. An exhaust pipe can be connected to this connection spigot 69, which leads to the exhaust air outlet 21 ( Figs. 1 to 3 ) leads.

[0073] The first section 65 of the exhaust air branch line 64 extends essentially horizontally or with a slight incline of 1° to 5°, preferably 2° to 2.5°. This has the advantage that condensing steam from the exhaust air can flow back into the oven drain 33. The subsequent second section 67 of the exhaust air branch line 64 preferably runs at a similar or the same incline as the first section 65. Condensate and, if applicable, unsolidified grease can also flow back from there. Furthermore, any cleaning agent that may have entered these sections 65 and 66 can flow back into the oven drain 33 during the evacuation of the cleaning agent from the oven 3 and then flow on into the siphon device 35.

[0074] The grease collection device 59 also includes the grease extraction line 73, which preferably opens into the lower part of the grease collection container 61 or provides a means for the grease-water mixture collected in the grease collection container 61 to flow into the grease extraction line 73. This is facilitated by the fact that the grease extraction line 73 extends at a slight gradient of 1° to 5°, preferably 1.5° to 2°.

[0075] Reference is now made to Fig. 6 , which shows a perspective view of the only partially depicted rear side 10 of the cooking appliance 1 or 1'. As from Fig. 6As can be seen, the grease extraction line 73 extends beyond the rear 10 of the cooking appliance and is connected to a suction pump 77 via connecting line 75 or a connecting pipe section 75. The suction pump 77 serves to extract the grease-water mixture from the grease collection container 61 and to convey this mixture via a grease discharge line 82 into a grease collection container 95 (see figure). Fig. 7a ), such as a canister, a collection bin, etc.

[0076] The suction pump 77 is connected to the device control via a corresponding control and supply cable 79, the cable 79 extending from the suction pump 77 through an opening 81 in the rear 10 of the cooking appliance to the device control.

[0077] The grease discharge line 82 has a riser pipe 83, which is held at the rear 10 of the cooking appliance and extends substantially vertically upwards. A discharge pipe 85 of the grease discharge line 82 connects to this riser pipe 83. In the exemplary embodiment, this discharge pipe extends substantially horizontally and has a shut-off valve 87 at its end for shutting off the grease discharge line 82. A suitable connecting hose 96 and / or connecting pipe section can then be connected to the grease collection container for the collected grease or grease-water mixture, as shown in Fig. 7a shown.

[0078] According to the invention, the cooking device 1, 1' comprises a cleaning device with which at least the grease extraction line 73 and the grease collection container 61 can be rinsed in the opposite direction to the grease extraction device in order to remove both residues of the grease-water mixture and residues of the cleaning agent that entered the cooking device during the cleaning process, so that contamination of the extracted grease or grease-water mixture can be avoided as far as possible during the next grease extraction process.

[0079] From the water supply 45 ( Fig. 4In one embodiment, a water supply line 89 extends through the opening 90 in the rear wall 10 of the cooking appliance. This water supply line 89 opens into the riser pipe 83 above the suction pump 77. When water is supplied via the water supply line 89, the grease collection device 59 can thus be cleaned and rinsed from above the suction pump 77 through the riser pipe 83, the connecting line 75, the grease suction line 73, and the grease collection container 61. From there, the rinsed liquid, facilitated by the ramp-shaped end section 62, is discharged via the cooking chamber drain 33 into the siphon device 35.

[0080] In an alternative embodiment, the suction pump 77 can have a shut-off device at its pump inlet 78, which prevents cleaning agents from the grease extraction line 73 and the connecting line 75 from entering the suction pump 77. Accordingly, the water supply line 89 can open into the connecting pipe section 75 immediately before the pump inlet 78, from where flushing can occur up to the siphon device 35.

[0081] As from Fig. 6 As can be seen, two side cover walls 91 are provided, which are connected to the rear wall 10 of the cooking appliance by means of screws 93 via corresponding retaining elements 92, thus enabling a box-shaped structure that can be assembled with a corresponding cover wall (not shown). Advantageously, the entire arrangement of the suction pump 77 and its connections is then accessible for maintenance work without having to access the interior of the cooking appliance.

[0082] In Figs. 7a and 7b Figure 1 shows a further embodiment of the cleaning device of the cooking appliance. The cleaning device comprises the connecting hose 94, which is connected to the grease discharge line 82, in particular to the shut-off valve 87. For this purpose, the connecting hose 94 can be attached at a first end 94a to a pipe section and fixed by means of a clamp or the like, or it can be fastened to the pipe section by means of a screw or bayonet connection.

[0083] On the one hand, the connecting hose 94, as in Fig. 7aThe connecting hose 94 is shown to be connected to the grease collection container 95 in order to drain the grease into it. Advantageously, the connecting hose 94 is detachably connected to the grease collection container 95 so that it can be replaced if necessary. For this purpose, a second end 94b of the connecting hose 94 can have a corresponding connection, e.g. in the form of a screw or bayonet fitting.

[0084] The connecting hose 94 can further be designed as a water supply line and can be connected to a water source by means of a water supply 96, for example a tap, a pipe or the like, as shown schematically in Fig. 7b indicated. This allows a user to easily connect the readily accessible connecting hose 94 to a water source and thus rinse the entire grease collection device 59 for cleaning.

[0085] The water supply line 89 is in Figs. 7a and 7bShown as a dashed line, since it, like other water supply lines, can be optionally provided to allow flexible use or different cleaning options, e.g. in conjunction with the water supply 45.

[0086] The present invention is not limited to the illustrated embodiments. For example, several water supply lines can be provided, at least one of which leads directly into the grease collection container 61 and / or the grease extraction line 73.

[0087] In a further embodiment, a multi-way valve can be provided upstream of the pump inlet 78, with which supplied water can be introduced either sequentially or simultaneously into the connecting line 75 and the grease extraction line 73 or into the extraction pump 77 and the grease dispensing line 82 that follows thereafter.

[0088] In another embodiment, for example, the riser pipe 83 can be directly connected to the grease extraction line 73, and the extraction pump 77 can be arranged at the upper end of the riser pipe 83, at a height above the level of the drain opening 15 of the cooking chamber 3. This prevents cleaning fluid from reaching the extraction pump 77. The discharge pipe 85 is then connected to the outlet of the extraction pump 77.

[0089] The present invention thus enables the recovery of fat from the cooking chamber that is essentially or practically free of cleaning agents, the fat being primarily extracted from cooked foods. This significantly improves the quality of the recovered fat for further processing, for example, in cosmetics.

[0090] Furthermore, the significant advantage is realized that the harmful grease buildup in both the drain pump and the circulation pump, caused by grease penetrating the water reservoir, can be considerably reduced, thus also protecting the corresponding seals. This can significantly increase the service life and overall lifespan of the cooking appliance.

[0091] This also has the major advantage of avoiding any (negative) impact on the cooking quality. Reference symbol list:

[0092] 1 - Cooking appliance 3 - Cooking chamber 4 - Cooking chamber floor 5 - Cooking chamber door 6 - Technical compartment 7 - Fan wheel 8 - Door handle 9 - Display and control panel 10 - Rear wall of the cooking appliance 11 - Hand shower 12 - Motor 13 - Hand shower head 14 - Corner support 15 - Drain opening 17 - Temperature sensor 19 - Recessed hand shower head holder 20 - Transparent door panel 21 - Exhaust air outlet 22 - Cooking chamber atmosphere 23 - Rack trolley 25 - Frame 27 - Swivel casters 29 - Rack or rack frame 31 - Shelf rails 32 - Shelf level 33 - Cooking chamber drain 34 - Cooking chamber drain inlet 35 - Siphon assembly 36 - Siphon container 37 - Water reservoir 38 - Connecting flange 41 - Partition 43 - Cooking appliance drain 44 - Drain channel 45 - Water supply 47 - Arrow of the fresh water supply 49 - Water supply line 51 - Drain pump 53 - Drain line 55 - Supply line 57 - Circulation pump 58 - Connection opening to the siphon device 59 - Grease collection device 61 - Grease collection container 62 - Ramp-shaped end section 63 - Opening forExhaust branch line 64 - Exhaust branch line 65 - first section Exhaust branch line 67 - second section Exhaust branch line 69 - Exhaust pipe connection 71 - Grease extraction pipe connection opening 73 - Grease extraction line 75 - Connecting line 77 - Extraction pump 78 - Pump inlet 79 - Extraction pump control and supply cable 81 - Opening 82 - Grease discharge line 83 - Riser pipe 85 - Discharge pipe 87 - Shut-off valve 89 - Water supply line 90 - Opening 91 - Side cover 92 - Retaining element 93 - Screw 94 - Water supply line / connecting hose 94a - first end 94b - second end 95 - Grease collection container 96 - Water supply

Claims

1. A cooking appliance for commercial kitchens in the form of a combi-steamer (1, 1') comprising a cooking chamber (3) for cooking food to be cooked arrangeable on a plurality of cooking levels (32), or in the form of a rotisserie appliance comprising a cooking chamber for cooking food to be cooked arrangeable on a rotatable support for food to be cooked, wherein the cooking appliance further comprises a heating device for heating a cooking chamber atmosphere, an appliance controller for controlling the cooking appliance, and a cooking chamber outlet (33) located below a floor (4) of the cooking chamber (3) and provided for draining off a fat-water mixture and gaseous components of the cooking chamber atmosphere from the cooking chamber (3), wherein the cooking chamber outlet (33) extends from a drain opening (15) in the floor (4) or in the floor region of the cooking chamber (3) to a siphon device (35), wherein a fat collection device (59) is provided, which comprises at least one fat collection container (61), at least one fat extraction line (73), at least one suction pump (77) and at least one fat discharge line (82), wherein the fat extraction line (73) extends from the fat collection container (61) to the suction pump (77), wherein the suction pump (77) is configured to convey the fat-water mixture extracted via the fat extraction line (73) into the fat discharge line (82), and wherein a cleaning device is provided, characterized in that the cleaning device is configured to convey water at least via the fat extraction line (73) and the fat collection container (61) into the cooking chamber outlet (33) in a direction towards the siphon device (35).

2. The cooking appliance according to claim 1, characterized in that the fat collection container (61) is located in an initial region of the cooking chamber outlet (33).

3. The cooking appliance according to one of the preceding claims, characterized in that an end portion (62) of the fat collection container (61) is configured in a ramp-shaped manner in a direction towards the siphon device (35).

4. The cooking appliance according to one of the preceding claims, characterized in that a branch line (64) for draining off gaseous components of a fluid or vapours discharged from the cooking chamber (3) into the cooking chamber outlet (33) branches off the cooking chamber outlet (33) between the fat collection container (61) and the siphon device (35).

5. The cooking appliance according to one of the preceding claims, characterized in that the water of the cleaning device used for flushing the fat collection device (59) is heated.

6. The cooking appliance according to one of the preceding claims, characterized in that the suction pump (77) is configured as a pump which can be flowed through in both directions, whereby it is capable of being flowed through against a pumping direction.

7. The cooking appliance according to one of the preceding claims, characterized in that the fat discharge line (82) comprises a riser pipe (83) arranged at a pump outlet of the suction pump (77) and extending upwardly from there along a certain portion.

8. The cooking appliance according to one of the preceding claims, characterized in that the cooking appliance, in particular the cleaning device, has a water supply (45).

9. The cooking appliance according to claim 8, characterized in that the fat collection device (59) has a shut-off valve at an inlet of the water supply (45) of the cleaning device into the fat extraction line (73), such that, after shutting off the fat extraction line (73), the cleaning device is able to clean the suction pump (77) and the fat discharge line (82) by flushing through.

10. The cooking appliance according to claim 8, depending on claim 7, characterized in that the water supply (45) comprises at least one water supply line (89) leading into the riser pipe (83) above the suction pump (77).

11. The cooking appliance according to one of the preceding claims, characterized in that the fat collection device (59) comprises the cleaning device.

12. The cooking appliance according to one of the preceding claims, characterized in that the cleaning device comprises a water supply line (94) connected to the fat discharge line (82), in particular to a discharge pipe (85) or a shut-off valve (87) of the fat discharge line (82), and which is connectable to a water source.

13. A method for operating a commercial kitchen cooking appliance, in particular a combi-steamer (1, 1') or a rotisserie appliance, and for collecting fat produced during a cooking process, the method comprising the following steps: collecting a fat-water mixture escaping from a cooking chamber (3) of the cooking appliance (1, 1'), via a drain opening (15) thereof, within a fat collection container (61) of a fat collection device (59) connected to a cooking chamber outlet (33) of the cooking appliance (1, 1'), extracting the fat-water mixture via at least one fat extraction line (73) from the fat collection container (61) by means of a suction pump (77) arranged at an end of the fat extraction line (73), discharging the fat-water mixture extracted by the suction pump (77) via a fat discharge line (82) to a fat storage tank (95), and carrying out a cleaning process of the fat collection device (59) after completing a cleaning process of the cooking appliance (1, 1'), by conveying water in a reverse direction to an extraction direction at least through the fat extraction line (73) and the fat collection container (61) into the cooking chamber outlet (33) in a direction towards a siphon device (35) at an end of the cooking chamber outlet (33) of the cooking appliance (1, 1').

14. The method according to claim 13, characterized in that an operation of the suction pump (77) is performed in a clocked manner.

15. The method according to claim 14, characterized in that the clocking is performed as a function of the food to be cooked and / or the cooking process.

16. The method according to any one of claims 13 to 15, characterized in that, during the cleaning process, water is conveyed through the fat discharge line (82), preferably through the entire fat discharge line (82), the fat extraction line (73) and the fat collection container (61) into the cooking chamber outlet (33).

17. The method according to one of claims 13 to 16, characterized in that the cleaning process of the fat collection device is performed both at the beginning and at the end of the cleaning process of the cooking appliance (1, 1').

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