Method of cleaning a cooking cavity

Abstract

The invention relates, among other things, to a cooking appliance (2) comprising a cooking chamber (4), a distribution system (12) for a cleaning liquid for cleaning the cooking chamber (4) and a circulation system (14) for circulating the cleaning liquid with a pump (16), a drain line (18) and an inlet line (20), wherein the pump (16) is connected by means of the drain line (18) in a flow-conducting manner to a drain (22) of the cooking chamber (4) arranged in a cooking chamber floor (6) of the cooking chamber (4) and by means of the inlet line (20) in a flow-conducting manner to an inlet opening (24) of the distribution system (12), and wherein the distribution system (12) has a distribution disc (26) with a pivot pin (28) for connection, preferably for torque-transmitting connection, with a shaft of the cooking appliance (2). Furthermore, the invention relates to a distribution disc (26), a distribution system (12) and a method for cleaning the cooking chamber (4) of the cooking appliance (2).

Description

[0001] The invention relates to a method for cleaning the cooking chamber with a cleaning liquid and to a cooking appliance with a cooking chamber.

[0002] Such distribution discs, distribution systems, cooking appliances with cooking chambers, and methods for cleaning them with a cleaning fluid are already known. For example, similar distribution discs are shown in the publications EP 3 190 344 A1 and EP 3 527 894 A1, EP 3 346 192 A1, and DE 10 2017 112 824 A1.

[0003] Water from a fresh water supply or from a storage container in the cooking appliance is used as a cleaning fluid. This is also disclosed, for example, in WO 2017 025 450 A1.

[0004] The invention addresses the problem of improving the cleaning of a cooking chamber of a cooking appliance with a cleaning liquid.

[0005] According to the invention, this problem is solved by a method having the features of patent claim 1 and a cooking appliance having the features of patent claim 9. Advantageous embodiments and further developments of the invention emerge from the following dependent claims.

[0006] The advantage achievable with the invention lies in the particular improvement in the cleaning of a cooking chamber of a cooking appliance with a cleaning fluid. By means of the invention, the cleaning of dirty areas in the cooking chamber is significantly improved through more targeted and thus more effective, as well as time- and cost-effective, exposure to cleaning fluid. The cleaning fluid can be, for example, water from a fixed water connection or from a storage container of the cooking appliance. However, other cleaning fluids are also conceivable. For example, water from a fixed water connection or from a storage container of the cooking appliance could be mixed with a cleaning agent concentrate or the like to the cleaning fluid for cleaning the cooking chamber.

[0007] Furthermore, the distributor disc can be connected to the cooking appliance either permanently or detachably, or simply for the purpose of cleaning the cooking chamber. Furthermore, the distributor disc according to the invention can be driven either by its own drive or by the force of the cleaning fluid. Accordingly, the distributor disc according to the invention can be advantageously used for a variety of different applications.

[0008] In a preferred embodiment of the distributor system according to the invention, the distributor disc is only partially arranged in the distributor housing.

[0009] The cooking appliance according to the invention also enables the cleaning liquid to be circulated, so that less cleaning liquid is used and cleaning is therefore more efficient.

[0010] The method according to the invention further enables the execution of different cleaning programs for needs-based cleaning of the cooking chamber. By varying the rotational speed of the distribution disc of the distribution system, for example, the throw curve of the cleaning fluid can be adjusted as desired, so that areas of the cooking chamber located at different distances from the distribution system can be advantageously reached using the cleaning fluid delivered by the distribution system. The aforementioned variation in the rotational speed also enables an alternating and thus pulsating application of cleaning fluid to the individual areas of the cooking chamber.

[0011] An advantageous development of the cooking appliance according to the invention provides that the pump is designed as a reversible pump. In this way, the cleaning liquid can be pumped against the circulation direction of the circulation system, thus backflushing the cooking chamber drain. The pump also allows for the intensity of the backflushing of the drain to be controlled. For example, the pump for backflushing the drain can be operated at maximum power in order to convey any solids blocking the drain as far away from the drain as possible. This allows sufficient time for these solids to flow back with the cleaning liquid towards the drain for the solids to be broken down by the cleaning liquid in such a way that they can be discharged unhindered from the cooking chamber through the drain.

[0012] Analogously, an advantageous development of the aforementioned embodiment of the method according to the invention provides that, during the backwashing state, the pump conveys the cleaning fluid through the drain counter to the circulation direction of the circulation system. This allows backwashing of the drain using the cleaning fluid, for example, without the need for additional lines or the like.

[0013] An alternative or additional development of the cooking appliance according to the invention provides that the pump is designed and arranged in such a way that, when the pump is switched off, a gravity-induced backflow of the cleaning liquid is possible.

[0014] This makes it possible to backwash the cooking chamber drain against the circulation direction of the circulation system even without the pump operating, by using the amount of cleaning fluid present in the inlet line, the pump and the drain line to backwash the drain.

[0015] Analogously, an advantageous development of the method according to the invention provides that the pump is switched off during the backwash state in such a way that the cleaning liquid is conveyed through the drain by means of gravity against the circulation direction of the circulation system.

[0016] A particularly advantageous development of the cooking appliance according to the invention provides that the distributor housing is arranged outside the cooking chamber and the distributor disc, on the one hand, dips into the distributor housing with a side of the distributor disc facing the distributor housing through an opening in a cooking chamber wall of the cooking chamber and, on the other hand, protrudes with the base plate through the opening into the cooking chamber with a side of the distributor disc facing the cooking chamber. In this way, it is possible to supply the distributor disc with water particularly well. This design also makes it possible to minimize the space required for the distributor system according to the invention in the cooking chamber and / or to enable more even wetting of the cooking chamber walls bordering the cooking chamber, i.e. the cooking chamber floor, the cooking chamber ceiling and the side cooking chamber walls.

[0017] An advantageous development of the aforementioned embodiment of the cooking appliance according to the invention provides that the distribution disc is designed and arranged in the cooking chamber such that the base plate of the distribution disc essentially covers the opening in the cooking chamber wall when viewed from the cooking chamber perpendicular to the base plate. This effectively protects the shaft connected to the pivot pin of the distribution disc, preferably connected in a torque-transmitting manner, as well as an electric drive of the cooking appliance driving this shaft from heat radiation from the cooking chamber. Accordingly, the energy efficiency of the cooking appliance according to the invention is also increased. Furthermore, this results in a visually pleasing overall impression of the cooking chamber.

[0018] The distribution system can thus have an electric drive connected to the pivot pin of the distribution system in a torque-transmitting manner. This allows the pivot pin and thus the distribution disc to be driven independently of the supply of cleaning fluid. Accordingly, the rotational speed of the distribution disc, i.e., its rotational speed, can be used to adjust the throw curve of the cleaning fluid independently of the amount of cleaning fluid supplied to the distribution disc. Furthermore, it is possible to control the electric drive in such a way that the distribution disc operates opposite to the usual direction of rotation, allowing cleaning fluid to be conveyed to the cooking chamber ceiling, for example.

[0019] Alternatively or additionally, another advantageous development of the cooking appliance according to the invention provides that the inlet opening and the distributor disc of the distributor system are designed and arranged in relation to one another in such a way that the distributor disc can be driven by means of the cleaning liquid. In this way, on the one hand, a drive of the distributor disc is made possible independently of an electric drive of the distributor disc. Accordingly, an electric drive of the distributor disc can generally be dispensed with. For example, it is conceivable that the rotational speed of the distributor disc can be changed by varying the flow rate of cleaning liquid through the inlet opening of the distributor system. For this purpose, it is possible, for example, to vary the flow rate of cleaning liquid or a free cross-section in the inlet opening as desired.

[0020] A particularly advantageous development of the cooking appliance according to the invention provides that the distribution system is arranged approximately centrally on a cooking chamber wall designed as a cooking chamber ceiling, preferably that the distribution system is arranged substantially vertically above the drain. This results in a particularly favorable arrangement of the distribution system relative to the cooking chamber of the cooking appliance, as this ensures that the individual areas of the cooking chamber are effectively supplied with cleaning fluid. The preferred embodiment of this development also has the advantage that the drain can be cleaned by means of the distribution system according to the invention without any additional construction or circuitry effort. For example, cleaning of the drain is achieved in a structurally particularly simple manner in that the cleaning fluid can be directed from the distribution system directly to the drain due to gravity.In particular, with this arrangement of distribution disc and drain, vertically one above the other, the cleaning fluid can drip or flow from the distribution disc directly onto the drain when the distribution disc is stationary.

[0021] One aspect of the invention is that the distributor disc and the drain are spaced apart by at least 15 centimeters, preferably greater than 20 centimeters. This distance has proven sufficient to ensure that the cleaning fluid dripping or flowing from the distributor disc, upon impacting the drain or a strainer of the drain, has sufficient kinetic energy to break down the suspended matter deposited there, thus automatically removing and / or preventing clogging of the strainer and / or the drain.

[0022] Another advantageous development of the cooking appliance according to the invention provides that the inlet line is additionally connected to the outlet in a flow-conducting manner by means of a bypass line of the circulation system, wherein the bypass line can be closed in non-bypass mode by means of at least one valve. In this way, a gravity-induced backflow of the cleaning fluid and thus a backwash of the cooking chamber drain against the circulation direction of the circulation system is possible, even with pumps that are not designed as reversible pumps or as pumps that do not allow a gravity-induced backflow of the cleaning fluid.

[0023] Analogously, an advantageous development of the method according to the invention provides that the inlet line is directly connected to the outlet in a flow-conducting manner by means of the bypass line during the backwash state, so that the cleaning liquid is conveyed through the outlet by means of gravity in the bypass mode against the circulation direction of the circulation system.

[0024] A further advantageous development of the cooking appliance according to the invention provides that the cooking appliance has a steam generator, wherein the steam generator can be fluidly connected to the drain via a steam line during steam cleaning operation, and the steam line can be blocked by at least one valve during non-steam cleaning operation. This enables a highly efficient method of cleaning the drain that is an alternative to using cleaning fluid.

[0025] A particularly advantageous development of the aforementioned embodiment of the cooking appliance according to the invention provides that the steam line comprises the inlet line and the outlet line or the drain line, wherein the inlet line or the drain line can be blocked during steam cleaning operation by means of at least one valve such that no steam escapes from the inlet opening of the distribution system. In this way, on the one hand, the inlet line and the drain line or the drain line can be used to conduct the steam from the steam generator to the drain, so that the need for an additional steam line is minimized. Furthermore, the steam can be used not only to clean the drain, but also to clean and sterilize the inlet line and the drain line or the drain line.

[0026] Analogous to the last two embodiments mentioned, an advantageous further development of the method according to the invention provides that the steam generator is connected to the drain during the steam cleaning operation by means of the steam line indirectly, by means of the inlet line and the drain line or the drain line, or directly in a flow-conducting manner, so that steam generated by means of the steam generator is conveyed through the drain.

[0027] In the method according to the invention, it is provided that the cleaning program is designed such that at the beginning of the at least one cleaning cycle, the distributor disc is operated at a maximum rotational speed of the cleaning cycle and the rotational speed is reduced after a predetermined period of time. Due to the maximum rotational speed at the beginning of each of the at least one cleaning cycle, for example, any inertia, contamination or sticking of the distributor system is overcome or a jamming of the rotational axis is prevented. By subsequently reducing the rotational speed, for example, the consumption of electrical energy is reduced. A maximum rotational speed of the distributor disc correlating to the maximum rotational speed of the distributor disc can be, for example, 5000 revolutions per minute.The speed can subsequently be reduced, for example, continuously or discontinuously, to a value of 0 revolutions per minute. According to the invention, the maximum speed lies in a range between 3000 and 9000 revolutions per minute.

[0028] A further advantageous development of the method according to the invention provides that in at least one of the at least one cleaning cycle, at least one sudden increase, preferably a plurality of sudden increases, in the rotational speed of the distributor disc occurs after a maximum rotational speed of the distributor disc in this cleaning cycle, wherein each sudden increase is directly followed by a decrease in the rotational speed. This makes it possible to apply a surge of cleaning fluid to the cooking chamber walls, i.e. the cooking chamber floor, the cooking chamber ceiling, and the side cooking chamber walls, in a manner that is simple in terms of design and circuitry. Accordingly, the mechanical cleaning of the cooking chamber walls by means of the cleaning fluid is significantly improved.

[0029] According to the invention, the maximum speed of the distributor disc is selected in a range of 3000 to 9000 revolutions per minute.

[0030] Starting from a lower speed in the range of 0 to 10 revolutions per minute, the maximum speed is reached within a period of 3 to 10 seconds, preferably 7 seconds. The selected maximum speed and / or the time required to reach the maximum speed enable a particularly wide and even distribution of the cleaning fluid across all surfaces of the cooking chamber.

[0031] After the maximum speed has been reached, the rotation speed of the distributor disc is reduced again until it reaches an intermediate speed. This occurs over a period of 10 to 40 seconds, preferably within a period of 30 seconds. This reduction in rotation speed also contributes to the even wetting of the cooking chamber surfaces with cleaning fluid.

[0032] One aspect is that the intermediate speed is in a range between 900 and 3000 revolutions per minute.

[0033] Preferably, two different intermediate speeds are provided. A first intermediate speed is in a range between 900 and 2000 revolutions per minute and / or lower than the second intermediate speed, and a second intermediate speed is in a range between 1000 and 3000 revolutions per minute and / or lower than the maximum speed.

[0034] It can be provided that after the time period after the maximum speed has elapsed, which comprises, for example, 30 seconds, the rotational speed of the distributor disc is initially reduced to the first intermediate speed.

[0035] One aspect is that after reaching the first intermediate speed, the rotational speed of the distributor disc is increased to the second intermediate speed. This increase in rotational speed preferably occurs within a maximum of 5 seconds, preferably in less than 1 second.

[0036] According to a preferred embodiment, the first intermediate speed is 1000 revolutions per minute and the second intermediate speed is 1500 revolutions per minute.

[0037] Such an impulse through a short-term increase in the rotational speed makes it possible to mechanically remove dirt from the surface through kinetic forces of the impacting cleaning fluid.

[0038] One aspect is that the maximum speed and / or the first intermediate speed and / or the second speed is not maintained or is only maintained for a few seconds, maximum for 3 seconds.

[0039] Another aspect is that after the maximum speed, in particular after the intermediate speed or the intermediate speeds, the rotational speed of the distributor disc is set to an upper speed.

[0040] The time until the upper speed is reached is preferably 30 to 100 seconds, in particular approximately 60 seconds. It is also possible to maintain the upper speed for a period of up to 40 seconds.

[0041] After reaching the upper speed or after the upper speed has been maintained, the rotational speed of the distributor disc is suddenly reduced to a lower speed within less than one second or a few seconds.

[0042] The upper speed is in a range between 400 and 900 revolutions per minute, in particular at about 700 revolutions per minute, preferably lower than the first intermediate speed and / or higher than a middle speed or than the lower speed.

[0043] The lower speed is in a range between 0 and 10 revolutions per minute, preferably lower than the middle speed or the upper speed.

[0044] The average speed in a range between 100 and 400 revolutions per minute, preferably lower than the upper speed and / or higher than the lower speed.

[0045] The period in which the lower speed is maintained is up to 10 seconds long, preferably the duration of the period of the lower speed is about 5 seconds.

[0046] For example, the aforementioned reduction can be carried out in stages, namely a reduction from the maximum speed of 5000 revolutions / minute to a first intermediate speed of 1000 revolutions / minute within a period of 30 seconds, followed by a sudden increase in the speed from the first intermediate speed of 1000 revolutions / minute to a second intermediate speed of 1500 revolutions / minute within less than a second or a few seconds, thereafter a reduction in the speed from the second intermediate speed of 1500 revolutions / minute to an upper speed of 700 revolutions / minute within a period of approximately 60 seconds and finally a sudden reduction in the speed from the upper speed of 700 revolutions / minute to the lower speed with preferably 0 revolutions / minute within less than a second or a few seconds.

[0047] In principle, the at least one cleaning cycle stored in the cleaning program can be freely selected within wide, suitable limits.

[0048] An advantageous development of the method according to the invention provides that the at least one cleaning cycle has a sawtooth-like profile in a speed-time diagram. In this way, the exposure of the cooking chamber walls to the cleaning fluid is pulsating throughout the entire cleaning cycle. For example, the maximum speed of the distributor disc at the beginning of a cleaning cycle, analogous to the above, can be 5000 revolutions / minute and then gradually reduced within 45 seconds to an upper speed value of 700 revolutions / minute. Subsequently, within 45 seconds, the speed can be steadily increased again from 700 revolutions / minute to the maximum speed of 5000 revolutions / minute. Thereafter, within 45 seconds, the speed can be steadily reduced again to an upper speed value of 700 revolutions / minute.subsequently increased continuously from 700 revolutions / minute to the maximum speed of 5000 revolutions / minute within 45 seconds, then continuously reduced again within 45 seconds to the upper speed with a value of 700 revolutions / minute and finally, within less than 5 seconds, preferably within a period of less than one second, abruptly reduced from 700 revolutions / minute to a lower speed of less than 10 revolutions / minute, preferably from 0 revolutions / minute.

[0049] One aspect of the invention is that between the upper speed and the lower speed, there is also an intermediate speed, which lies in a speed range between 100 and 400 revolutions per minute. Preferably, this intermediate speed is maintained for a period of at least 20 seconds, preferably up to 200 seconds, at the end of the cleaning process. This improves rinsing of the cooking chamber floor.

[0050] Alternatively or additionally, the medium speed holding phase can also be inserted during the cleaning process at regular or irregular intervals between the usual cycles. During this intermediate rinsing, the holding time can also be shorter, for example, between 5 and 30 seconds.

[0051] In addition to the aforementioned controls of the rotational speed of the distributor disc, i.e. the rotational speed of the distributor disc, over time, it is also conceivable that the pump is also switched on and off in a predetermined manner in order to further improve the mechanical cleaning of the cooking chamber walls by means of the cleaning fluid.

[0052] One aspect of the invention is that the lower speed is maintained for a period of at least 1 second, preferably at least 2.5 seconds, and up to 10 seconds before the distributor disc is accelerated again to a medium speed or upper speed or maximum speed.

[0053] A particularly advantageous development of the method according to the invention provides that the distribution system is operated in such a way that, during the cleaning process, the lateral cooking chamber walls and the cooking chamber floor and / or the lateral cooking chamber walls and the cooking chamber ceiling are directly exposed to cleaning fluid from the distribution system. Preferably, a rotational speed of the pivot pin is matched to the diameter D of the base plate in such a way that, by means of the distribution disc, essentially the lateral cooking chamber walls and the cooking chamber floor and / or the lateral cooking chamber walls and the cooking chamber ceiling are essentially completely exposed to cleaning fluid. This enables thorough cleaning of essentially all areas of the cooking chamber that are susceptible to contamination.By means of the preferred embodiment of this further development, a thorough cleaning of essentially the entire cooking chamber is realized in a simple manner in terms of construction and control technology.

[0054] A further advantageous development of the method according to the invention provides that the at least one cleaning cycle is designed as a plurality of cleaning cycles, and between two directly consecutive cleaning cycles, a predetermined time period is provided, during which the rotational speed of the distributor disc is reduced to a lower speed of less than 10 revolutions per minute, preferably to zero. Preferably, the aforementioned time period is provided after each individual cleaning cycle or after a predetermined number of consecutive cleaning cycles. In this way, it is possible to clean an area of ​​the cooking chamber arranged essentially vertically beneath the distributor disc in a structurally and circuit-technically simple manner.This is particularly advantageous if the distributor disc is positioned essentially vertically above the drain located in the cooking chamber floor, as this allows for particularly easy cleaning of the drain, which is prone to clogging. The aforementioned period can be, for example, a period of 5 seconds. For example, cleaning the drain is achieved in a particularly simple design by allowing the cleaning fluid from the distribution system to be directed directly onto the drain by gravity.

[0055] Another advantageous development of the method according to the invention provides that, after automatic detection of a blockage in the drain and / or at predetermined time intervals during the cleaning process, the circulation system is operated in a backwash state such that the cleaning fluid is pumped through the drain against a circulation direction of the circulation system. Preferably, the pump pumps the cleaning fluid through the drain against the circulation direction of the circulation system during the backwash state, or the pump is switched off during the backwash state such that the cleaning fluid is pumped through the drain by gravity against the circulation direction of the circulation system. This makes it possible to automatically eliminate the blockage in the drain or to largely prevent it.Automatic detection of a drain blockage is possible, for example, through the pump's power consumption or pump speed monitoring. However, other methods known to those skilled in the art for automatically detecting blockages are also possible. Examples include cameras for monitoring the cooking chamber or flow meters in the drain line.

[0056] By using a sieve in the fluid circuit, blockages only occur between the cooking chamber and the sieve. The sieve is preferably arranged upstream of a pump and / or a valve. To automatically eliminate or largely prevent a blockage of the sieve, another advantageous development of the method according to the invention provides that, after automatic detection of a blockage of the sieve and / or at predetermined intervals during the cleaning process, the circulation system is operated in a backwash state such that the cleaning fluid is pumped through the sieve against the circulation direction of the circulation system.

[0057] According to one embodiment, the sieve is arranged in the area of ​​the drain and / or the drain line.

[0058] A further advantageous development of the method according to the invention provides that the respective period between the predetermined time intervals is automatically determined depending on the cleaning process. This enables the drain to be backwashed as needed, depending on the respective cleaning process.

[0059] The terms rotational speed and angular speed are synonymous and, when related to a complete revolution, are equivalent to the specification of speed.

[0060] The different speed ranges are structured in such a way that the lower speed is in a range between 0 and 10 revolutions / minute and / or is lower than the middle speed; the middle speed is in a range between 100 and 400 revolutions / minute and / or is lower than the upper speed; the upper speed is in a range between 400 and 900 revolutions / minute and / or is lower than the first intermediate speed; the first intermediate speed is in a range between 900 and 2000 revolutions / minute and / or is lower than the second intermediate speed; the second intermediate speed is in a range between 1000 and 3000 revolutions / minute and / or is lower than the maximum speed; the maximum speed is in a range between 3000 and 9000 revolutions / minute.

[0061] An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows Figure 1 shows a first embodiment of the cooking appliance according to the invention in a sectional side view, in partial representation, in the circulation mode, Figure 2 shows an embodiment of the distribution system according to the invention for the embodiment of the cooking appliance according to the invention according to the Fig. 1 with the distributor disc according to the invention in a sectional side view, in partial representation, Figure 3 the embodiment from Fig. 2 in a further sectional side view, in partial representation, Figure 4 the embodiment of the distributor disc according to the invention from Fig. 2 and 3 in a perspective view, Figure 5 the embodiment of the distributor disc according to the invention from the Fig. 2 to 4 in a further perspective view, Figure 6 the embodiment of the distributor disc according to the invention from the Fig. 2 to 5in a side view, Figure 7 the embodiment of the distribution system according to the invention from Fig. 2 in a side view, Figure 8 the embodiment of the distribution system according to the invention from Fig. 2 in a partially sectioned side view, Figure 9 shows a first speed-time diagram for the embodiment of Fig. 1 , Figure 10 a second speed-time diagram for the embodiment of Fig. 1 , Figure 11 a third speed-time diagram for the embodiment of Fig. 1 , Figure 12 the embodiment from Fig. 1 in a further sectional side view, in partial representation, in the backwash state of the circulation system, Figure 13 the embodiment from Fig. 1 in analogous representation to Fig. 1, highlighting the area of ​​the circulation system filled with water when the drain is blocked, and Figure 14 shows a second embodiment of the cooking appliance according to the invention in a sectional side view, in partial representation, in bypass mode.

[0062] In Fig. 1a first embodiment of the cooking appliance according to the invention is partially shown. The cooking appliance 2 is designed as a steam cooker and comprises a cooking chamber 4 with a cooking chamber floor 6, a cooking chamber ceiling 8 and lateral cooking chamber walls 10 as cooking chamber walls, a distribution system 12 for a cleaning liquid (not shown) designed as water for cleaning the cooking chamber 4 and a circulation system 14 for circulating the cleaning liquid with a pump 16, a drain line 18 and an inlet line 20, wherein the pump 16 is connected by means of the drain line 18 in a flow-conducting manner to an outlet 22 of the cooking chamber 4 arranged in the cooking chamber floor 6 of the cooking chamber 4 and by means of the inlet line 20 in a flow-conducting manner to an inlet opening 24 of the distribution system 12, wherein the distribution system 12 has a distribution disc 26 with a pivot pin 28 for torque-transmitting connection to a shaft (not shown) of the cooking appliance 2. See the Fig. 2 . In the present embodiment, the cleaning fluid is stored in a reservoir 30, which is fluidly connected to the pump 16 of the circulation system 14 in a manner not shown, in order to fill the circulation system 14 with cleaning fluid. The distribution system 12 is in the Fig. 2 to 8 shown in more detail.

[0063] The distributor system 12 comprises a distributor housing 32 and the distributor disc 26 arranged in the distributor housing 32 so as to be rotatable relative to the distributor housing 32, wherein the distributor housing 32 has the inlet opening 24 for supplying the distributor disc 26 with cleaning fluid and surrounds the distributor disc 26 such that an annular space 34 with a circumferential outlet opening 36 for the cleaning fluid is formed between the distributor housing 32 and the distributor disc 26. As can be seen from the Fig. 2 , 3 , 7 and 8As can be seen, the distributor disc 26 is only partially arranged in the distributor housing 32.

[0064] In the assembled position, the distributor disc 26, with a side facing the distributor housing 32, extends through the cooking chamber wall 8, which forms the cooking chamber ceiling, into the annular space 34 of the distribution system 12. This makes it possible to supply the distributor disc 26 with water particularly effectively. This design also makes it possible to minimize the space required in the cooking chamber 4 and / or to enable more uniform wetting of the cooking chamber walls bordering the cooking chamber 4, namely the cooking chamber floor 6, the cooking chamber ceiling 8, and the side cooking chamber walls 10.

[0065] The distributor disc 26 of the distribution system 12 comprises the pivot pin 28 for the torque-transmitting connection to the shaft (not shown) of the cooking appliance 2, a base plate 40 arranged on the pivot pin 28 substantially perpendicular to a longitudinal axis 38 of the pivot pin 28, and four vanes 42 arranged symmetrically between the pivot pin 28 and the base plate 40, wherein a chamber 44 is formed between directly adjacent vanes 42, each delimited by the pivot pin 28, the base plate 40, and these two vanes 42. The vanes 42 are identical to one another, wherein each of the vanes 42 forms an acute angle with the longitudinal axis 38 of the pivot pin 28. See in particular the Fig. 3 to 6. In the present embodiment, each of the wings 42 has, starting from the base plate 40, a first wing section 42a and a second wing section 42b adjoining the first wing section 42a in the direction of a free end of the wing 42, wherein the first wing section 42a forms an angle α of 75° with the base plate 40 and the second wing section 42b forms an angle β of 85° with the base plate 40. See the Fig. 3 to 8 , especially the Fig. 6 .

[0066] Furthermore, each of the wings 42 extends substantially to a free end of the base plate 40 and to a free end of the pivot pin 28, wherein the respective wing 42 has an L-shape. See in particular the Fig. 2 and 4 to 6. The pivot pin 28 has an outer diameter d of 8 mm and each of the L-shaped wings 42 has a height h of 6 mm at its free end assigned to the base plate 40 and a height H of 22 mm at its free end assigned to the pivot pin 28. The base plate 40 of the distributor disc 26 has a circular diameter D of 50 mm. The distributor disc 26 is made of steel. Alternatively, it is conceivable for the distributor disc to be made of plastic or ceramic or glass. In order to protect a distributor disc made of plastic from undesired temperature stress, the distributor disc can have a coating, for example of aluminum, on the side facing the cooking chamber floor. It is also possible for the distributor disc to be made of a combination of the materials mentioned above. For example, the distributor disc can be made of a metal and coated with plastic and / or ceramic or glass.Glass coated.

[0067] The diameter D of the base plate 40 is designed to match the rotational speed of the pivot pin 28 such that essentially the entire cooking chamber 4 can be supplied with cleaning fluid by means of the distributor disc 26. Furthermore, the diameter D of the base plate 40 is selected to be large enough that the base plate 40 of the distributor disc 26 covers the outlet opening 36 in the cooking chamber ceiling 8 when viewed perpendicularly from the cooking chamber 4 onto the base plate 40.

[0068] In the present exemplary embodiment, the distributor housing 32 is arranged outside the cooking chamber 4, with the distributor disc 26, on the one hand, dipping into the distributor housing 32 with a side of the distributor disc 26 facing the distributor housing 32 through the outlet opening 36 in the cooking chamber ceiling 8 of the cooking chamber 4, and on the other hand, with a side of the distributor disc 26 facing the cooking chamber 4, with the base plate 40, protruding through the outlet opening 36 into the cooking chamber 4. This makes it possible to supply the distributor disc 26 with water particularly well. This design also makes it possible to minimize the space required for the distributor system 12 in the cooking chamber 4 and to enable more uniform wetting of the cooking chamber walls bordering the cooking chamber 4, namely the cooking chamber floor 6, the cooking chamber ceiling 8, and the side cooking chamber walls 10.

[0069] In the present embodiment, the distribution system 12 has an electric drive 45 which is connected to the pivot pin 28 of the distribution system 12 by means of the shaft (not shown) in a torque-transmitting manner. See in particular the Figs. 7 and 8 . Furthermore, the distribution system 12 is arranged approximately centrally on the cooking chamber ceiling 8 of the cooking chamber 4 and substantially vertically above the drain 22, wherein the distribution system 12 is positioned between the cooking chamber ceiling 8 and a cooking chamber heating element (not shown) attached to the cooking chamber ceiling 8. See the Fig. 1 and 12 to 14 . Furthermore, the inlet opening 24 and the distributor disc 26 of the distribution system 12 are designed and arranged relative to one another in such a way that the distributor disc 26 can be driven by the cleaning fluid.

[0070] In the present embodiment, the pump 16 of the circulation system 14 is designed as a reversible pump, wherein the pump 16 is designed and arranged such that, when the pump 16 is switched off, a gravity-induced backflow of the cleaning fluid from the inlet line 20, the pump 16, and the outlet line 18 toward the outlet 22 is possible. This is opposite to the circulation direction of the circulation system 14 symbolized by the arrows 46.

[0071] The functioning of the cooking appliance according to the invention with the distribution system according to the invention, which has the distribution disc according to the invention, and the method according to the invention according to the present first embodiment are described below with reference to Fig. 1 to 13 explained in more detail.

[0072] For the purpose of cleaning the cooking chamber 4 of the cooking appliance 2 using the cleaning fluid, a cleaning process is initiated in the cooking appliance 2 in a manner known to those skilled in the art, for example, manually via a control unit (not shown) or automatically as an automatic program. During the cleaning process, the distributor disc 26 is supplied with cleaning fluid via the inlet line 20 and the inlet opening 24, wherein a rotational speed of the distributor disc 26 of the distribution system 12 is varied depending on a previously defined cleaning program stored in a control system (not shown) of the cooking appliance 2. The cleaning program is designed such that at the beginning of each of three cleaning cycles, the distributor disc 26 is operated at a maximum rotational speed of the cleaning cycle and the rotational speed is reduced after a predetermined period of time. See the Fig. 9, in which the above-mentioned cleaning process with a total of three cleaning cycles is shown as an example in a speed-time diagram.

[0073] As can be seen from this, each cleaning cycle begins with a maximum rotational speed which is the same for all three cleaning cycles. It starts at the maximum speed in order to overcome any increased inertia. This increased inertia can be caused by sticking or contamination of the rotational axis. The maximum speed therefore ensures that the highest torque is available at the start of the cleaning cycle, which counteracts any jamming of the rotational axis or loosens an already jammed rotational axis. After that, the rotational speed in each cleaning cycle initially decreases steadily, then increases briefly, before decreasing steadily again. Shortly before the end of each cleaning cycle, the rotational speed of the distributor disk 26 reduces to 0 m / s, i.e. 0 revolutions per minute. In the present embodiment, each of the three cleaning cycles lasts 50 s.The maximum speed per cleaning cycle is 5,000 revolutions per minute. However, individual cleaning cycles can also be shorter or longer.For example, the aforementioned reduction can take place in stages as follows: a reduction from the maximum speed of 5000 revolutions per minute to a first intermediate speed of 1000 revolutions per minute over a period of 30 seconds, followed by a sudden increase in speed from the first intermediate speed of 1000 revolutions per minute to a second intermediate speed of 1500 revolutions per minute within less than a second or a few seconds, thereafter a reduction in speed from the second intermediate speed of 1500 revolutions per minute to an upper speed of 700 revolutions per minute over a period of around 60 seconds and finally a sudden reduction in speed from the upper speed of 700 revolutions per minute to a lower speed, preferably 0 revolutions per minute, within less than a second or a few seconds. See also the . Fig. 9The direction of rotation of the distributor disc 26 about the longitudinal axis 38 is determined such that during the cleaning process, in particular the lateral cooking chamber walls 10 and the cooking chamber floor 6 are directly exposed to cleaning fluid from the distributor system 12.

[0074] In principle, however, the minimum cleaning cycle stored in the cleaning program can be freely selected within wide, suitable limits.

[0075] For example, the individual cleaning cycle of the cleaning program and thus the method according to the invention can be carried out according to the Fig. 10 The speed-time diagram shown in the figure can be modified. Analogous to the variant according to the Fig. 9 Each of the three cleaning cycles is also identical. As can be seen from the Fig. 10As can be seen, the speed, i.e. the rotational speed, of the distributor disc 26 at the beginning of each cleaning cycle is 5000 revolutions / minute as above. Thereafter, the speed of the distributor disc 26 is gradually reduced, whereby in the first 30 seconds after the beginning of the respective cleaning cycle, the speed of the distributor disc 26 is increased four times in steps and is reduced again immediately after each increase, whereby the speed of the distributor disc 26 is reduced to a speed below the maximum speed of 5000 revolutions / minute for each of the aforementioned increases. The speed, which is increased several times in steps in this way, decreases continuously from the first increase in speed to the fourth increase in speed. See the Fig. 10After the fourth increase, the speed of the distributor disc 26 is reduced to 700 revolutions / minute over a period of 60 seconds. At the end of each cleaning cycle, the speed of the distributor disc 26 is finally reduced abruptly to 0 revolutions / minute within less than one second or a few seconds.

[0076] In the Fig. 11 A further variant of the method according to the invention is shown by way of example, according to which the at least one cleaning cycle is carried out in the Fig. 11The speed-time diagram shown has a sawtooth-like profile. Thus, the cleaning fluid is applied to the cooking chamber walls, namely the cooking chamber floor 6, the cooking chamber ceiling 8, and the side cooking chamber walls 10, in a pulsating manner throughout the entire cleaning cycle.For example, the maximum speed of the distributor disc 26 at the beginning of a cleaning cycle, analogous to the above, can be 5000 revolutions / minute and then gradually reduced to an upper speed of 700 revolutions / minute within 45 seconds, then gradually increased again from 700 revolutions / minute to the maximum speed of 5000 revolutions / minute within 45 seconds, then gradually reduced again to a value of 700 revolutions / minute within 45 seconds, then gradually increased again from 700 revolutions / minute to 5000 revolutions / minute within 45 seconds, then gradually reduced again to a value of 700 revolutions / minute within 45 seconds and finally abruptly reduced from 700 revolutions / minute to a lower speed of less than 10 revolutions / minute, preferably 0 revolutions / minute within less than one second or a few seconds. become.In addition to the aforementioned control of the rotational speed over time, this variant of the method according to the invention also provides for the pump 16 to be switched on and off in a predetermined manner in order to further improve the mechanical cleaning of the cooking chamber walls, i.e., the cooking chamber floor 6, the cooking chamber ceiling 8, and the side cooking chamber walls 10, by means of the cleaning fluid. As can be seen from the . Fig. 11 As further stated, the cleaning program may also comprise fewer or more than three cleaning cycles. This applies generally and is not limited to the specific embodiment of the method according to the invention. Furthermore, in embodiments of the method according to the invention, it may be provided that, in the case of a plurality of cleaning cycles, only the first cleaning cycle begins with the maximum rotational speed of the distributor disc, i.e. the maximum rotational speed of the distributor disc. See also the Fig. 11 .

[0077] The cleaning program can further provide for the direction of rotation of the distributor disc 26 to be temporarily reversed about the longitudinal axis 38, so that during the cleaning process the lateral cooking chamber walls 10 and the cooking chamber ceiling 8 are directly supplied with cleaning fluid from the distributor system 12. During the aforementioned reversal of the direction of rotation of the distributor disc 26, the cleaning fluid is directed towards the cooking chamber ceiling 8 by means of the inclined vanes 42. The speed of the shaft transmitting torque via the pivot pin 28, and thus of the pivot pin 28, is matched to the diameter D of the base plate 40 in such a way that the lateral cooking chamber walls 10 and the cooking chamber floor 6, as well as the lateral cooking chamber walls 10 and the cooking chamber ceiling 8, are essentially completely supplied with cleaning fluid by means of the distributor disc 26.

[0078] In all three aforementioned variants of the inventive method according to the Fig. 9 to 11it is provided that between two directly successive cleaning cycles a predetermined period of time is provided in which the speed, i.e. the rotational speed, of the distributor disc 26 is reduced to zero, namely that the aforementioned period of time is provided after each individual cleaning cycle. In this way, it is possible to clean the area of ​​the cooking chamber 4 arranged vertically below the distributor disc 26 in a structurally and circuit-technically simple manner. This is particularly advantageous because the distributor disc 26 is arranged vertically above the drain 22 arranged in the cooking chamber floor 6 of the cooking chamber 4, since this allows the drain 22, which is prone to blockages, to be cleaned in a particularly simple manner. The aforementioned period of time can, for example, be a period of 5 seconds.For example, cleaning of the drain 22 is realized in a particularly simple structural manner in that the cleaning liquid can be directed from the distribution system 12 directly to the drain 22 due to gravity.

[0079] Should the drain 22 become clogged with solids during the cleaning process, the circulation system 14 is automatically operated in a backwash state, with the cleaning fluid being pumped through the drain 22 against the circulation direction 46 of the circulation system 14. A blockage can be automatically detected, for example, by means of the power consumption of the pump 16 or by monitoring the speed of the pump 16. However, other measures known to those skilled in the art for the automatic detection of blockages are also possible. By way of example, reference is made here to cameras for monitoring the cooking chamber or flow meters in the drain line. However, it is also conceivable for the circulation system 14 to be operated in the backwash state at predetermined intervals in order to avoid blockage of the drain 22 as far as possible.The respective period between the previously defined time intervals is automatically determined depending on the cleaning process, for example.

[0080] In the present embodiment, the pump 16 conveys the cleaning liquid during the backwash state against the circulation direction 46 of the circulation system 14 through the outlet 22. See the Fig. 12 This is possible because the pump 16 is designed as a reversible pump. The conveyance of the cleaning fluid against the circulation direction 46 is Fig. 12 symbolized by arrows 48.

[0081] However, backwashing of drain 22 is also possible in other ways.

[0082] For example, by switching off the pump 16 during the backwash state in such a way that the cleaning fluid is conveyed by gravity through the outlet 22 against the circulation direction 46 of the circulation system 14. See the Fig. 12 and13 . In Fig. 13 The area of ​​the inlet line 20, the pump 16, and the outlet line 18, which is filled with cleaning fluid when the drain 22 is blocked, is highlighted by a dash-dotted frame 50. Since the pump 16 in the present embodiment enables a gravity-induced backflow of the cleaning fluid, this type of backwash is also possible.

[0083] In the Fig. 14 A second embodiment of the cooking appliance according to the invention is shown. The second embodiment is largely identical to the first embodiment, so only the differences will be explained below. Otherwise, reference is made to the above explanations regarding the first embodiment. Identical or equivalent components are designated by the same reference numerals.

[0084] In the second embodiment of the cooking appliance according to the invention, the inlet line 20 is additionally connected to the outlet 22 in a flow-conducting manner by means of a bypass line 52 of the circulation system 14, wherein the bypass line 52 can be blocked in a non-bypass mode by means of at least one valve 54. During the backwash state, the inlet line 20 is directly connected to the outlet 22 in a flow-conducting manner by means of the bypass line 52, so that the cleaning liquid in the Fig. 14 shown bypass operation is conveyed by gravity against the circulation direction of the circulation system 14, namely in the direction of the arrows 48, through the outlet 22.

[0085] The invention is not limited to the present embodiments.

[0086] For example, the invention can also be advantageously used in other types of cooking appliances with cooking chambers. It is also conceivable for the cooking appliance to have a steam generator, wherein the steam generator can be fluidly connected to the drain by means of a steam line in a steam cleaning mode, and the steam line can be blocked by means of at least one valve in a non-steam cleaning mode. This enables a highly efficient cleaning of the drain as an alternative to the use of the cleaning liquid. The steam line can comprise the inlet line and the drain line or the drain line, wherein the inlet line or the drain line can be blocked by means of at least one valve in the steam cleaning mode such that no steam escapes from the inlet opening of the distribution system.In this way, on the one hand, the inlet line and the outlet line or the outlet line can be used to conduct the steam from the steam generator to the drain, so that the need for an additional steam line is minimized. Furthermore, not only the drain can be cleaned by means of the steam, but also the inlet line and the outlet line or the outlet line can be cleaned and sterilized. Accordingly, a further embodiment of the method according to the invention provides that the steam generator is connected to the drain during steam cleaning operation by means of the steam line indirectly, by means of the inlet line and the outlet line or the outlet line, or directly in a flow-conducting manner, so that steam generated by the steam generator is conveyed through the drain.

[0087] In contrast to the exemplary embodiments explained, it is also possible that the inlet opening and the distributor disc of the distribution system are designed and arranged relative to one another in such a way that the distributor disc can only be driven by means of the cleaning liquid.

[0088] By using a sieve in the fluid circuit, i.e., in the circulation system, blockages only occur between the cooking chamber and the sieve. The sieve is preferably arranged upstream of the pump and / or upstream of a valve of the circulation system. To automatically eliminate or largely prevent a blockage of the sieve, another advantageous development of the method according to the invention provides that, after automatic detection of a blockage of the sieve and / or at predetermined intervals during the cleaning process, the circulation system is operated in a backwash state such that the cleaning fluid is pumped through the sieve against the circulation direction of the circulation system.

[0089] According to one embodiment, the sieve is arranged in the area of ​​the drain and / or the drain line.

[0090] A further advantageous development of the method according to the invention provides that the respective period between the predetermined time intervals is automatically determined depending on the cleaning process. This enables the drain to be backwashed as needed, depending on the respective cleaning process.

Claims

1. Method for cleaning a cooking chamber (4) of a cooking appliance (2) by means of a cleaning liquid during a cleaning process having at least one cleaning cycle, the cooking appliance (2) being designed having a cooking chamber (4), a distribution system (12) for a cleaning liquid for cleaning the cooking chamber (4), and a circulation system (14) for circulating the cleaning liquid, having a pump (16), an outlet line (18) and an inlet line (20), the pump (16) being fluidically connected by means of the outlet line (18) to an outlet (22) of the cooking chamber (4), which outlet is arranged in a cooking chamber floor (6) of the cooking chamber (4), and being fluidically connected by means of the inlet line (20) to an inlet opening (24) of the distribution system (12), and the distribution system (12) comprising a distribution disc (26) having a pintle (28) for connection, preferably for torque-transmitting connection, to a shaft of the cooking appliance (2), the method comprising the following method steps: - supplying the distribution disc (26) with cleaning liquid by means of the inlet line (20) and the inlet opening (24); - varying a rotational speed of the distribution disc (26) of the distribution system (12), a rotational speed of the distribution disc (26) being varied on the basis of a predetermined cleaning program stored in a control means of the cooking appliance (2), characterised in that the cleaning program is designed such that, at the beginning of the at least one cleaning cycle, the distribution disc (26) is operated at a maximum rotational speed of the cleaning cycle, and the rotational speed is reduced after a predetermined time interval, and the maximum rotational speed is in a range between 3,000 and 9,000 revolutions per minute.

2. Method according to the preceding claim, characterised in that, in at least one of the at least one cleaning cycles, at least one abrupt increase, preferably a plurality of step-like increases, in the rotational speed of the distribution disc (26) takes place in this cleaning cycle following a maximum rotational speed of the distribution disc (26), an abrupt increase being directly followed by a decrease in the rotational speed in each case.

3. Method according to the preceding claim, wherein the time period between the maximum rotational speed and the abrupt increase to an intermediate rotational speed is approximately 30 seconds.

4. Method according to any of the preceding claims, characterised in that the distribution system (12) is operated in such a way that, during the cleaning process, lateral cooking chamber walls (10) and the cooking chamber floor (6) and / or the lateral cooking chamber walls (10) and the cooking chamber ceiling (8) are directly supplied with cleaning liquid by the distribution system (12), preferably in that a rotational speed of the pintle (28) is adapted to the diameter D of the base plate (40) such that substantially the lateral cooking chamber walls (10) and the cooking chamber floor (6) and / or the lateral cooking chamber walls (10) and the cooking chamber ceiling (8) are substantially completely supplied with cleaning liquid by means of the distribution disc (26).

5. Method according to any of the preceding claims, characterised in that the at least one cleaning cycle is designed as a plurality of cleaning cycles, and a predetermined time period is provided between two temporally successive cleaning cycles, in which period the rotational speed of the distribution disc (26) is reduced to a lower rotational speed, preferably to zero, preferably in that the aforementioned time period is provided after each individual cleaning cycle or after a predetermined number of temporally successive cleaning cycles.

6. Method according to any of the preceding claims, wherein the lower rotational speed is in a range between 0 and 10 revolutions / minute, and / or wherein the time period for which the lower rotational speed is maintained is at least 1 second and up to 10 seconds.

7. Method according to the preceding claim, wherein, after the time period of the lower rotational speed has elapsed, the distribution disc is accelerated again to a medium rotational speed or upper rotational speed or maximum rotational speed.

8. Method according to any of the preceding claims, characterised in that, after automatic detection of a blockage of the outlet (22) and / or at predetermined time intervals during the cleaning process, the circulation system (14) is operated in a backflushing state in such a way that the cleaning liquid is conveyed against a circulation direction (46) of the circulation system (14) through the outlet (22), preferably in that the pump (16), during the backflushing state, conveys the cleaning liquid against the circulation direction (46) of the circulation system (14) through the outlet (22), or in that the pump (16) is switched off during the backflushing state such that the cleaning liquid is conveyed by means of gravity against the circulation direction (46) of the circulation system (14) through the outlet (22).

9. Cooking appliance (2) having a cooking chamber (4), a distribution system (12) for a cleaning liquid for cleaning the cooking chamber (4), and a circulation system (14) for circulating the cleaning liquid, having a pump (16), an outlet line (18) and an inlet line (20), the pump (16) being fluidically connected by means of the outlet line (18) to an outlet (22) of the cooking chamber (4), which outlet is arranged in a cooking chamber floor (6) of the cooking chamber (4), and being fluidically connected by means of the inlet line (20) to an inlet opening (24) of the distribution system (12), and the distribution system (12) comprising a distribution disc (26) having a pintle (28) for connection, preferably for torque-transmitting connection, to a shaft of the cooking appliance (2), characterised in that the cooking appliance (2) comprises a control means which is set up and designed to carry out the method according to any of the preceding claims.

10. Cooking appliance (2) according to the preceding claim, characterised in that the distribution system (12) is arranged approximately centrally on a cooking chamber wall (8) of the cooking chamber (4) designed as a cooking chamber ceiling, preferably in that the distribution system (12) is arranged above the outlet (22).

11. Cooking appliance (2) according to either of the two preceding claims, wherein the distribution disc (26) comprises a base plate (40) arranged on the pintle (28) substantially perpendicularly to a longitudinal axis (38) of the pintle (28) and comprises at least three, preferably four, symmetrically arranged vanes (42) arranged between the pintle (28) and the base plate (40), wherein a space (44) is formed between directly adjacent vanes (42), which space is delimited by the pintle (28), the base plate (40) and these two vanes (42).

12. Cooking appliance according to the preceding claim, wherein each of the vanes (42), starting from the base plate (40), comprises a first vane portion (42a) and a second vane portion (42b) adjoining the first vane portion (42a) in the direction of a free end of the vane (42), wherein the first vane portion (42a) forms an angle (α) with the base plate (40) and the second vane portion (42b) forms an angle (β) with the base plate (40).

13. Cooking appliance according to either of the two preceding claims, wherein the distribution system (12) comprises a distribution housing (32) and the distribution disc (26) which is arranged, preferably only partially, in the distribution housing (32) so as to be rotatable relative to the distribution housing (32), wherein the distribution housing (32) comprises an inlet opening (24) for supplying the distribution disc (26) with cleaning liquid and surrounds the distribution disc (26) such that an annular space (34) having a circumferential outlet opening (36) for the cleaning liquid is formed between the distribution housing (32) and the distribution disc (26).

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