Method for cleaning and regeneration of catalyst within oven cleaning system

Abstract

A combined oven using a non-corrosive detergent during a clean wash cycle and adding a catalyst regeneration cycle after a predetermined number of clean wash cycles can regenerate the catalyst to restore almost all of the functions of the catalyst, and removing a majority of clogging of the pores of the catalyst occurring during the oven cooking and clean wash cycles. The catalyst regeneration cycle comprises a rinsing agent cycle and subsequent high-temperature drying and burning-off steps.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 342,697, filed on May 17, 2022, which is incorporated herein by reference in its entirety. Background Art

[0003] The present invention relates to ovens for preparing food and in particular to a combination oven providing individually controlled convection heating and steam generating heating in each cooking zone and providing catalytic treatment of cooking fumes.

[0004] Combination steam and convection ovens ("combination ovens") use a combination of convection and steam to cook. In convection cooking, heated air is rapidly circulated through a cooking compartment to break down the insulating layer of air surrounding the food, thereby increasing the rate of heat transfer. Since the specific heat of water is higher than that of dry air, steam increases the rate of heat transfer to the food and may also reduce moisture loss from the food. Combination ovens are described, for example, in U.S. Patents 7,307,244 and 6,188,045, which are assigned to the assignee of the present invention and are incorporated herein by reference.

[0005] Combination ovens may be arranged to be cleaned by introducing water into the cooking cavity along with a detergent. The water and detergent may be heated by the oven fan and heater and circulated in a high-speed, atomized mist. Commercial cooking ovens may employ cleaning cycles using water and detergent as well as various cycles of flushing water and steam to clean the oven interior at regular intervals.

[0006] Combination ovens also produce cooking fumes and odors as they cook food, which are typically handled by an exhaust hood that provides powered ventilation for the fumes and odors in the kitchen. In some cases, where an exhaust hood is impractical or undesirable (ventless ovens), it is known to treat such cooking fumes using catalytic converters, which break down the components of the cooking fumes in a catalytic chemical process. In some cases, catalysts may also be used in conjunction with exhaust hoods.

[0007] Commercial cooking ovens may use catalysts in one or more exhaust streams to reduce smoke and odor levels in the kitchen. However, catalyst systems cannot be used in the same oven with a cleaning cycle because the caustic detergents used in the cleaning cycle are known to clog the pores of the catalyst, which prevents the catalyst from being able to work properly. Summary of the invention

[0008] The present invention further improves upon the prior art by providing a combination oven or multi-function oven having both a detergent cleaning system and a catalyst system that uses a catalyst regeneration cycle to restore catalyst function.

[0009] The inventors have recognized that the combination of a non-corrosive detergent used in the cleaning cycle and a catalyst regeneration cycle added after a predetermined number of clean cooking and washing cycles is able to regenerate the catalyst to restore nearly full functionality of the catalyst and remove most of the clogging of the catalyst's pores that occurs during repeated oven cooking and cleaning cycles.

[0010] In one embodiment of the present invention, a combination oven includes: an insulated housing including a door and an opening, the door being configured to close to define an internal cooking cavity, the opening providing an entrance to the cooking cavity; a cooking cavity heater communicating with the cooking cavity to heat the cooking cavity in response to a temperature signal; a steam generator for generating steam within the cooking cavity in response to a steam generation signal; a catalyst chamber for eliminating smoke and fumes within the cooking cavity; and a controller communicating with the cooking cavity heater and the steam generator and executing a program stored in a memory during a cleaning mode to: (i) control the circulation of detergent material through the catalyst chamber; (ii) control the circulation of rinse agent through the catalyst chamber; and (iii) control the operation of the cooking cavity heater in response to the temperature signal.

[0011] It is therefore a feature of at least one embodiment of the invention to allow a detergent cleaning system to be used in conjunction with a catalyst system in the same oven by regenerating the catalyst function when the cleaning detergent impairs the catalyst function.

[0012] The rinse agent may be an acetic acid solution.

[0013] It is therefore a feature of at least one embodiment of the invention that the catalyst chamber is rinsed during a catalyst regeneration cycle in order to clear clogging of pores in the catalyst caused by cleaning detergents used during repeated cleaning cycles.

[0014] Acetic acid solution can be in tablet or liquid form.

[0015] It is thus a feature of at least one embodiment of the invention to allow a user to easily fill an oven with a rinse chemical that passes through the same cleaning system as the detergent.

[0016] The acetic acid solution may be a 5% to 10% acetic acid solution.

[0017] It is therefore a feature of at least one embodiment of the invention to remove organic deposits on a catalyst.

[0018] The detergent may be a non-corrosive detergent.

[0019] It is therefore a feature of at least one embodiment of the invention to use a detergent that minimizes deposits that build up due to repeated cooking cycles and thus cause catalyst clogging.

[0020] The steam generator heater may be independent of the cooking chamber heater.

[0021] It is therefore a feature of at least one embodiment of the invention to provide high thermal drying of moisture and burn-off of organic deposits on the catalyst during a catalyst regeneration cycle to regenerate the catalyst.

[0022] A fan may be used to circulate air to the cooking cavity heater.

[0023] It is thus a feature of at least one embodiment of the invention to assist in circulating cleaning detergent and rinse agent through the oven during the cleaning cycle and catalyst regeneration cycle, respectively.

[0024] The controller can execute a program stored in the memory during a cooking mode and a cleaning mode to: control the operation of the cooking cavity heater according to a first temperature signal during the cooking mode and a second temperature signal during the cleaning mode; and control the operation of the steam generator according to a first steam generation signal during the cooking mode and a second steam generation signal during the cleaning mode.

[0025] It is thus a feature of at least one embodiment of the invention to operate separate cooking, cleaning, and catalyst regeneration cycles wherein heating and steam are achieved during each cycle but at different temperatures and steam generation levels.

[0026] Controlling operation of the cooking cavity heater during the cleaning mode may increase the temperature of the oven to a temperature of at least 500 degrees Fahrenheit for at least one hour.

[0027] It is therefore a feature of at least one embodiment of the invention to heat the oven to a temperature sufficiently high, above most cooking temperatures, to dry the rinse solution and burn off organic deposits on the catalyst.

[0028] The third temperature signal may raise the temperature of the oven to a temperature higher than the oven temperatures in the first temperature signal and the second temperature signal.

[0029] In an alternative embodiment of the present invention, a method for operating a cleaning mode of a combination oven includes: providing an oven having an insulated housing, a cooking cavity heater, a steam generator and a controller, wherein the insulated housing includes a door and an opening, the door being configured to close to define an internal cooking cavity, the opening providing an entrance to the cooking cavity, the cooking cavity heater being in communication with the cooking cavity to heat the cooking cavity, the steam generator being used to generate steam in the cooking cavity in response to a steam generation signal, the steam generator having a water input nozzle and a steam generator heater independent of the cooking cavity heater, the controller being in communication with the cooking cavity heater and the steam generator; circulating detergent material through a catalyst chamber during at least one cleaning cycle; circulating rinse agent through the catalyst chamber during a catalyst regeneration cycle; and operating the cooking cavity heater in response to the temperature signal during the catalyst regeneration cycle.

[0030] It is therefore a feature of at least one embodiment of the invention that a rinse cycle and a catalyst regeneration cycle are implemented after oven cleaning to restore full functionality of the catalyst in order to reduce smoke and odor levels in the kitchen environment.

[0031] The step of operating the cooking cavity heater raises the temperature of the oven to a temperature of at least 500 degrees F. The step of operating the cooking cavity heater lasts for at least one hour.

[0032] It is therefore a feature of at least one embodiment of the invention to cause drying of the rinse agent and burning off of organic deposits.

[0033] The method may further include circulating the detergent material through the cooking cavity heater and the steam generator. The method may further include circulating the detergent material through a steam generator heater independent of the cooking cavity heater. The method may further include circulating the detergent material through a fan for circulating air to the cooking cavity heater.

[0034] It is thus a feature of at least one embodiment of the invention to allow cleaning in areas of an oven that are prone to grease and residue buildup and to perform a rinse cycle using the same circulation path.

[0035] These specific objects and advantages may apply only to some embodiments falling within the claims and therefore do not limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a perspective view of a four-cavity oven according to one embodiment of the present invention showing expanded detail of a rack comprised of separate upper and lower air chambers that are individually removable through an open door of the oven;

[0037] Figure 2 It is along Figure 1A cross-sectional view taken along line 2-2 of FIG. 1 showing isolated internal air passages in the shelf that may, for example, conduct air of different temperatures while maintaining thermal separation between cavities through active insulation and other techniques;

[0038] Figure 3 is a simplified block diagram of an air delivery system and water control valve for steam generation and cleaning feedback control;

[0039] Figure 4 It passes through Figure 1 A schematic cross-section of a partial view of a plurality of cavities of FIG. 1 showing airflow from a fan and heater system into the cavities via shelves dividing the cavities;

[0040] Figure 5 It passes through Figure 1 a plan schematic cross-section of one cavity of an oven of , showing a fan and steam generating system and a catalyst located within a single airflow path for drawing air into and out of the cooking cavity;

[0041] Figure 6 is a cleaning cycle diagram showing a predetermined number of cooking cycles and cleaning cycles followed by a catalyst regeneration cycle implemented by the oven controller. DETAILED DESCRIPTION

[0042] Now refer to Figure 1 The multi-zone combination oven 10 may provide a housing 12 having upright insulated left and right outer side walls 14a, 14b, and an upright insulated outer rear wall 14c extending between and connecting opposite, generally horizontal, insulated outer upper walls 14d and 14e. The walls 14 enclose a volume 16 open to the front, and as is generally understood in the art, the volume 16 may be covered by a hinged door 18 when the door 18 is in a closed position. The housing 12 may be supported on one or more legs 21 extending downwardly from a bottom surface of the bottom wall 14e.

[0043] The cooking volume 16 may be divided into a plurality of cooking cavities 20a to 20d. Although four cooking cavities are shown, the present invention contemplates a range of 2 to 6 cooking cavities 20 spaced apart vertically. Each of the cooking cavities 20 is separated by shelves 22a to 22c, wherein shelf 22a separates cavity 20a from 20b, shelf 22b separates cavity 20b from 20c, and shelf 22c separates cavity 20c from 20d.

[0044] Also refer to Figure 2, each shelf 22 may be composed of a generally rectangular divided upper air chamber 24a and a lower air chamber 24b fitted horizontally in the cooking volume 16, wherein the air chamber 24a faces the upper cavity 20 and the air chamber 24b faces the lower cavity 20. The single upper air chamber 24a forms the bottom closest to the lower cavity 20d and the single lower air chamber 24b forms the upper wall closest to the upper cavity 20a.

[0045] The outer surface of each plenum 24 provides a horizontally extending air distribution plate 28 having a set of air flow openings 30 distributed over its area to provide a generally uniform air flow through the air flow openings 30. In one embodiment, the air flow openings 30 in the air distribution plate 28 may provide a series of holes 31 connected by slots 33 extending in a plurality of rows from the left side to the right side of the cavity 20, as described, for example, in U.S. Pat. No. 10,088,172, assigned to the assignee of the present invention and incorporated herein by reference.

[0046] Typically, the width of the slots 33 will be less than 0.05 inches and preferably less than 0.1 inches to reduce pressure losses in the passages 34 that may result from the large slot area. The holes 31 are much larger than the slots 33 and may be circular and may have a diameter in the range of 0.3 inches to 0.6 inches to provide air flow that helps direct the air from the slots 33 while also minimizing the loss of air pressure. The slot length may vary between 1 inch and 2 inches and is preferably about 1.6 inches. The air distribution plate 28 is a thin sheet of metal, such as stainless steel, having a thickness of less than 1 / 8 inch and typically less than 1 / 16 inch, such as may be easily formed using laser cutting techniques.

[0047] Air enters from the corresponding outlet at the rear of each cavity, through the side walls of each of the air chambers 24a and 24b at air inlets 32a and 32b, respectively. These air inlets 32 may be only one and a half inches high and are preferably less than one inch high. The air then passes from the air inlets 32a and 32b through a horizontally extending channel 34, which is defined by the inner surface of the air distribution plate 28 and the inner surface of a centralizing wall 36 opposite to the air distribution plate 28 with respect to the channel 34. The centralizing wall 36 has the maximum spacing relative to the air distribution plate 28 at the air inlet 32, and then bends inwardly toward the air distribution plate 28 as the air conducted in the channel 34 escapes through the air flow opening 30, and requires a smaller channel height. This inward tilting of the centralizing wall 36 for each of the air chambers 24a and 24b together provides an additional insulation area 38 between the barrier walls 36 of the upper air chamber 24a and the lower air chamber 24b, respectively, thereby minimizing the shelf height but maximizing the insulation value. The average spacing of barrier walls 36 may be about one inch, varying from contact between barrier walls to approximately two inches of spacing. The present invention contemplates an average spacing of at least one quarter inch and preferably at least one inch.

[0048] The peripheral wall 40 of each plenum 24 surrounds the air distribution plate 28 and the barrier wall 36 to enclose the air within the channel 34 in all directions except through the inlet 32 ​​and the air flow opening 30. The peripheral wall 40 also provides an inwardly extending horizontal protrusion 43 that can support a wire rack 45 at a spacing of about 1 / 4 inch and at least 1 / 8 inch above the upper limit of the air distribution plate 28 of the upper plenum 24a. In one embodiment, the wire rack 45 can be supported more than one inch above the air distribution plate 28 and desirably more than 1.5 inches above the air distribution plate by using a dedicated wire rack 45 or expander protrusion 43 (not shown). In this way, the cooking sheet or plate set on the top of the rack 22 rests on the wire rack 45 and does not block the air flow opening 30. In a preferred embodiment, the interval 44 ( Figure 1 and Figure 4 ) will be less than four inches, preferably less than three inches, and desirably less than two inches, thereby providing an extremely compact shelf that maximizes cavity space and minimizes overall height. Cavity 20 (in Figure 1 and Figure 4) will have a nominal height 42 of between four and nine inches, and preferably five inches or more, defined by the distance between the air distribution plates 28 that bound the upper and lower limits of the cavity 20. In one non-limiting example, each cavity may add about seven inches of height to the oven, so that three cavities may have a height of no more than 23 inches, or at least no more than 25 inches, and four cavities may have a nominal height of 30 inches and no more than 35 inches.

[0049] Typically, for durability and ease of cleaning, the shelves 22 may be constructed entirely of stainless steel, and although the present invention contemplates that thin insulation may also be incorporated into the shelves 22 in some embodiments, the present invention contemplates that non-metallic shelf structural materials are not required. The barrier walls 36 may be held within each plenum 24 in a "floating mount" that allows the barrier walls 36 to slide relative to the other structures of the plenum 24, such as by creating a sliding fit between these components, the sliding fit being enhanced by the natural flexing of the metal of the barrier walls 36 providing a light pressure between the barrier walls 36 and the inwardly extending lips of the ribs 29 and the peripheral wall 40.

[0050] Now refer to Figure 3 Each of the chambers 20 may be associated with a temperature sensor 41 that communicates with a controller 47, such as a microcontroller having one or more processors 48 that execute programs and communicate with an associated memory 49 that stores an operating program 51 and various recipe schedules 76. The temperature sensor 41 may be a thermistor, a resistive temperature sensor, or the like.

[0051] Each chamber 20 may also be associated with an airflow system 50 including a heater system, a fan motor, and a variable speed motor controller so that the controller 47 may independently control the airflow circulating through each chamber 20 over a continuous range, and may control the temperature of that air over a continuous temperature range. The heater system may be, for example, a resistive heater, such as a "cal" rod controlled by a solid state relay, or may be a heat exchanger of an electronically controllable gas burner system.

[0052] Optionally, each cavity 20 may have an electrically controllable wash water valve 52 in communication with a common water supply 54, so that water for cleaning may be introduced into the cavity by a signal sent from the controller 47 to the controllable wash water valve 52. An additional steam control valve 53 may be operated to allow water to be introduced into the heating unit of the air flow system 50, as will be discussed below, to allow independent control of humidity according to a cooking schedule. Mechanisms for introducing controlled humidity into an oven cavity 20 suitable for use with the present invention are described, for example, in U.S. Patents 9,375,021, 7,307,244, 7,282,674, and 6,188,045, all of which are assigned to the assignee of the present application and are incorporated herein by reference.

[0053] The controller 47 may also receive signals from a door switch 56 (e.g., a limit switch or proximity switch) and may provide input and output to an oven user via a user interface 58 such as, for example, a touch screen, a graphic display, a membrane switch, etc. as is known in the art. A data connector 60 may communicate with the controller 47 to allow easy uploading of a cooking plan 76 via the Internet or by transfer from a portable storage device, etc.

[0054] One or more of the chambers 20 may also include a smoker 61, for example, to provide a compartment that may contain wood chips or the like that will be heated by electrical elements controlled by the controller 47 through corresponding solid-state relays. For example, the construction of a smoker 61 suitable for use with the present invention is described in U.S. Patents 7,755,005; 7,317,173; and 7,157,668, which are assigned to the assignee of the present invention and are incorporated herein by reference.

[0055] Now refer to Figure 4 , the airflow system 50 for each chamber 20 (generally indicated by the separated dashed lines) can include a separate fan 62 independently controlled by a variable speed motor and motor drive 64. The fan 62 can be, for example, a squirrel cage fan, and the motor can be a DC synchronous motor driven by a solid-state motor controller of a type known in the art. The use of separate fans 62 allows for complete separation of the airflow within each chamber 20. The use of separate motors and motor drives 64 allows for independent air speed control of the air in each chamber 20.

[0056] The airflow system 50 may also include a heater 66, and air from each fan 62 may pass through the heater 66 to be received by a bifurcated manifold 68, which separates the heated airflow into an upper airflow 70 and a lower airflow 74. The upper airflow 70 enters the channel 34 ( Figure 2) and then as a set of downwardly directed airflows 72a from the airflow openings 30 (distributed over the lower region of the air chamber 24b) Figure 2 The lower airflow 74 enters the upper channel 34 of the upper air chamber 24a of the lower shelf 22 defining the lower wall of the cavity 20 to be discharged as a set of upwardly directed airflows 72b from the airflow openings 30 (shown in FIG. 1 ) distributed over the upper area of ​​the air chamber 24a. Figure 2 Each air flow opening in (shown in ) exits from the channel 34.

[0057] The diverging manifold 68 can be designed to provide a significantly greater airflow in the upper airflow 70 than in the lower airflow 74, for example, by constriction or orientation of the branches of the diverging manifold 68 relative to the natural circulation flow of the fan. In one example, the air can be split so that 53% to 60% of the heated air is distributed to the lower shelf that conveys air upward, and 40% to 57% of the heated air is distributed to the upper plenum that pulls downward, as described in the aforementioned U.S. Patent Application 15 / 016,093.

[0058] This arrangement of fans, airflow system 50 and bifurcated manifold 68 is repeated for each chamber 20. In the uppermost chamber 20a, only a single lower plenum 24b is provided at the top of the chamber 20a, and in the lowermost chamber 20d, only a single upper plenum 24a is provided, each plenum being effectively one half of a shelf 22.

[0059] Multi-zone ovens of this general design are discussed in U.S. Patents 10,684,022, 10,986,843, and U.S. Application 2021 / 0247075, which are assigned to the assignee of the present application and are incorporated herein by reference.

[0060] Now refer to Figure 5 In one embodiment, the fan 62 may be a centrifugal fan having a squirrel cage impeller mounted to rotate about a horizontal axis 80 extending from the right wall to the left wall of the oven 10 , wherein the fan 62 is centered relative to the volume of the cavity 20 .

[0061] Also positioned behind each chamber 20 and to the left of the fan 62, for example, is a steam generator 82 that provides a water injector 84 that provides a conduit and nozzle that directs a stream or water droplets to a diverter bracket 86. The diverter bracket 86 can be mounted around a steam heater tube 88 for generating steam of dispersed water droplets. The steam generator 82 can be as described in U.S. Application 63 / 212,943, assigned to the assignee of the present application and incorporated herein by reference.

[0062] The water injector 84 may disperse fresh water onto the diverter bracket 86 so that the water is dispersed and sprayed as a fine mist of water that is heated by the spiral heater tube of the heater 66 that surrounds the diverter bracket 86. The water to the water injector 84 may be controlled by the electronically controlled wash water valve 52. In this manner, the convection fan speed control motor 64, the heater 66, and the steam heater tube 88 are independently controlled to provide separate control of the heating of the oven cavity 20 and the steam generation of the oven cavity 20.

[0063] A catalyst chamber 120 is also positioned to the rear of each cavity 20 and to the left of the fan 62 and (for example) at the inlet of the fan 62, which provides a catalyst unit 122 positioned within the catalyst chamber 120 and within an airflow path 124 of return air 126 from the fan 62, so that the return air 126 enters the inlet orifice 128 and passes through the catalyst unit 122 and exits the outlet orifice 130 to eliminate smoke in the airflow by reducing the return air 126 to carbon dioxide and water.

[0064] Preferably, the catalyst unit 122 is a metal substrate coated with a catalytic material known in the art. Preferred catalytic converter materials are precious metal-based materials such as palladium or platinum / palladium-based substrates, such as those manufactured by Catalytic Combustion Corporation. The substrate layer is treated so that it forms a series of channels that are generally parallel to the flow of return air 126. Depending on the desired volume of return air 126 flowing through the catalyst chamber 120, the amount of cross-sectional area of ​​the catalyst unit 122, and the amount of flow resistance caused by any pressure differential, the number of channels per unit facial area can range from 40 to 350 channels per square inch. The necessary flow rate of return air 126 can be determined empirically, but generally will provide treatment of only a portion of the air within the cooking volume 16 per minute. As the return air 126 passes through the catalyst unit 122, the cooking fumes, including smoke and steam (i.e., volatile organic compounds) in the circulating airflow are more completely oxidized to CO2 and H2O to prevent the fumes from being recirculated into the cooking volume 16 or exhausted from the cooking volume 16 when the door 18 is opened or through a small amount of exhaust gas through the drain 108. The catalytic conversion process is generally exothermic, which will also provide some heat to the catalyst.

[0065] Catalysts suitable for use with the present invention are described, for example, in US Pat. No. 9,683,747, assigned to the assignee of the present application and incorporated herein by reference.

[0066] Still refer to Figure 5, air from fan 62, as heated by heater 66, can enter cavity 20 to heat the contained food, and then be drawn through side vent 90 into return duct 92 to pass again through heater 66. Side vent 90 is sized, for example, to provide a slight constriction, thereby creating a low pressure in the return duct, which can communicate with fresh air duct 94 directly or optionally controlled by valve 96, thereby providing air inlet from outside the oven. Valve 96 can be controlled by controller 47.

[0067] Likewise, chamber 20 will be at a slightly higher pressure due to the size of side vent 90 and may communicate with exhaust conduit 98 controlled by valve 100 via controller 47 to exhaust air and vapor from chamber 20 to the outside atmosphere as will be discussed below.

[0068] As described above, wash water may be introduced into chamber 20, for example, by spray nozzles in chamber 20 or in bifurcated manifold 68, or both. A system of drains 102 allows excess water to be drained into a holding container 104, where detergent material 106 and rinse agent 107 may be placed for cleaning. The container 104 may provide water to the wash water valve 52 via a pump (not shown) for recycling the clean water, and may provide a drain 108 to a fresh water supply and a fresh water replenishment valve 110, as is generally understood in the art.

[0069] Now refer to Figure 6 , within each cavity 20, the program 51 in the memory 49 of the controller 47 can provide independent operation of the fan 62, heater 66, and steam generator 82 to provide control of the temperature of the cooking cavity 20 during different cooking modes or cycles 129. The program 51 in the memory 49 of the controller 47 can also provide independent operation of the fan 62, heater 66, and steam generator 82 during cleaning and catalyst regeneration operations described below and in accordance with the cleaning schedule of the program 51 in the memory 49. For example, a cooking cycle 129 may be followed by a cleaning cycle 131 in accordance with the cleaning schedule of the program 51 in the memory 49.

[0070] During the cleaning cycle 131, the cleaning liquid or detergent material 106 uses the same flow path 124 as the return air 126. The detergent material 106 flows along the flow path 124, including flowing through the catalyst unit 122. The detergent material 106 is desirably a non-corrosive detergent, but may also be a corrosive detergent. The cleaning cycle 131 (and the cooking cycle 129) may be repeated a desired number of times before the catalyst regeneration cycle 132 is initiated by the cleaning schedule of the program 51 in the memory 49.

[0071] After a predetermined number of cooking cycles 129 and / or cleaning cycles 131 , the catalyst unit 122 is desirably regenerated to restore catalyst functionality. The catalyst regeneration cycle 132 is initiated by a cleaning schedule of the program 51 in the memory 49 .

[0072] Catalyst regeneration cycle 132 first includes a catalyst rinse cycle 134 consisting of recirculation of rinse agent 107 through flow path 124. As described above, rinse agent 107 follows the same path as wash water introduced into chamber 20, for example, through spray nozzles in chamber 20 or bifurcated manifold 68, or both.

[0073] During the catalyst rinse cycle 134, the rinse agent 107 uses the same flow path 124 as the return air 126 and detergent material 106. The rinse agent 107 flows along the flow path 124, including through the catalyst unit 122. The rinse agent 107 may be, for example, a 5% to 10% acetic acid tablet or liquid acetic acid solution.

[0074] After the catalyst rinse cycle 134, a high heat cycle 138 is implemented by the heater 66 and / or the steam heater tube 88 to drive off moisture and eliminate any potential organic deposits remaining on the catalyst unit 122. The high heat cycle 138 can last for at least one hour and can last for about one to two hours at a high temperature of at least 500 degrees Fahrenheit and at least 525 degrees Fahrenheit and at least 550 degrees Fahrenheit.

[0075] It is to be understood that the high heat cycle 138 is generally at a higher temperature than the cooking cycle 129 and the cleaning cycle 131, wherein the temperatures of the cooking cycle 129 and / or the cleaning cycle 131 are below 500 degrees Fahrenheit and below 525 degrees Fahrenheit and below 550 degrees Fahrenheit. After the high heat cycle 138, the cooking cycle 129 and / or the cleaning cycle 131 can be resumed, and the cooking schedule and the cleaning schedule can be repeated.

[0076] It will be appreciated that the combination of using the non-corrosive detergent material 106 during the cleaning cycle 131 and adding a catalyst regeneration cycle 132 after a predetermined number of cleaning cycles 131 can regenerate the catalyst unit 122 to restore nearly full functionality by removing organic deposits that have accumulated in the catalyst unit 122. The addition of the rinse agent 107 during the rinse cycle 134 and the high temperatures reached during the high heat cycle 138 allow the catalyst unit 122 to be used with the non-corrosive detergent cleaning system to minimize clogging of the catalyst pores, thereby allowing the detergent cleaning cycle 131 and the catalyst unit 122 to be used within the same oven 10, and within the same cooking cavity 20 and its corresponding airflow system 50.

[0077] The specific terms used in this article are used for reference purposes only and are therefore not intended to be limiting. For example, terms such as "upper", "lower", "above" and "below" refer to directions in the referenced drawings. Terms such as "front", "back", "rear", "bottom" and "side" describe the orientation of the parts of the components within a consistent but arbitrary reference system, which is clarified by reference to the text and associated drawings describing the components in question. Such terms may include the words specifically mentioned above, their derivatives, and words with similar meanings. Similarly, the terms "first", "second" and other such numerical terms referring to structures do not mean a sequence or order unless the context clearly indicates.

[0078] When introducing elements or features of the present disclosure and exemplary embodiments, the terms "a", "an", "the" and "said" are intended to mean that there are one or more such elements or features. The terms "comprising", "including" and "having" are intended to be inclusive and mean that additional elements or features may be present in addition to those specifically noted. It should also be understood that the method steps, processes and operations described herein are not interpreted as necessarily requiring execution in the particular order discussed or described, unless clearly identified as the order of execution. It should also be understood that additional or alternative steps may be adopted.

[0079] With respect to "microprocessor" and "processor" or "the microprocessor" and "the processor", it can be understood to include one or more microprocessors, which can communicate in an independent environment and / or a distributed environment, and can therefore be configured to communicate with other processors via wired communication or wireless communication, wherein such one or more processors can be configured to operate one or more processor-controlled devices that can be similar or different devices. In addition, with respect to memory, unless otherwise specified, it can include one or more processor-readable and accessible memory elements and / or components, which can be located inside the processor-controlled device, outside the processor-controlled device and can be accessed via a wired network or a wireless network.

[0080] It is specifically intended that the present invention is not limited to the embodiments and descriptions contained herein, and that the claims should be understood to include modifications of these embodiments including parts of the embodiments and combinations of elements of different embodiments as within the scope of the appended claims. All publications described herein, including patents and non-patent publications, are hereby incorporated by reference in their entirety.

[0081] To assist the Patent Office and any reader of any patent issuing from this application in interpreting the claims appended hereto, Applicants wish to point out that unless “means for” or “step for” is expressly used in a particular claim, Applicants do not intend for any claim or claim element in the appended claims to invoke 35 U.S.C. §112(f).

Claims

1. A combined oven, comprising: an insulated housing including a door configured to close to define an interior cooking cavity and an opening providing access to the cooking cavity; a cooking cavity heater, the cooking cavity heater being in communication with the cooking cavity to heat the cooking cavity according to a temperature signal; a steam generator, the steam generator being used to generate steam in the cooking cavity according to a steam generation signal; A temperature sensor, the temperature sensor is used to collect the temperature of the cooking cavity to provide a temperature signal; a catalyst chamber, the catalyst chamber being used to eliminate smoke and fumes in the cooking cavity; as well as a controller in communication with the cooking cavity heater, the steam generator, and executing a program stored in a memory during a cleaning mode to: (i) controlling the circulation of detergent material through the catalyst chamber; (ii) controlling the circulation of a rinse agent through the catalyst chamber; (iii) controlling the operation of the cooking chamber heater according to the temperature signal.

2. The combined oven according to claim 1, wherein: The rinse agent is an acetic acid solution.

3. The combined oven according to claim 2, wherein: The acetic acid solution is in tablet or liquid form.

4. The combined oven according to claim 3, wherein: The acetic acid solution is a 5% to 10% acetic acid solution.

5. The combined oven according to claim 1, wherein: The detergent is a non-corrosive detergent.

6. The combination oven of claim 1, further comprising a steam generator heater independent of the cooking cavity heater.

7. The combination oven of claim 1 further comprising a fan for circulating air to the cooking cavity heater.

8. The combined oven according to claim 1, wherein: The controller executes a program stored in memory during a cooking mode, a cleaning mode, and a catalyst regeneration mode to: controlling operation of the cooking cavity heater based on a first temperature signal during the cooking mode, a second temperature signal during the cleaning mode, and a third temperature signal during the catalyst regeneration mode; as well as The operation of the steam generator is controlled according to a first steam generation signal during the cooking mode, a second steam generation signal during the cleaning mode, and a third steam generation signal during the catalyst regeneration mode.

9. The combined oven according to claim 8, wherein: The third temperature signal increases the temperature of the oven to a temperature of at least 500 degrees Fahrenheit for at least one hour.

10. The combined oven according to claim 8, wherein: The third temperature signal increases the temperature of the oven to a temperature higher than the oven temperatures in the first temperature signal and the second temperature signal.

11. A method of operating a cleaning mode and a catalyst regeneration mode of a combination oven, the method comprising: An oven is provided, the oven having: an insulated housing including a door and an opening, the door being configured to close to define an interior cooking cavity, the opening providing access to the cooking cavity; a cooking cavity heater in communication with the cooking cavity to heat the cooking cavity; a steam generator, the steam generator being used to generate steam in the cooking cavity according to a steam generation signal; a temperature sensor, the temperature sensor being used to collect the temperature of the cooking cavity to provide a temperature signal; and a catalyst chamber, the catalyst chamber being used to eliminate smoke in the cooking cavity; and a controller, the controller being in communication with the cooking cavity heater and the steam generator; circulating a detergent material through the catalyst chamber during at least one cleaning cycle; circulating a rinse agent through the catalyst chamber during a catalyst regeneration cycle; as well as The cooking chamber heater is operated according to the temperature signal during a catalyst regeneration cycle.

12. The method according to claim 11, wherein: The step of operating the cooking cavity heater increases the temperature of the oven to a temperature of at least 500 degrees Fahrenheit.

13. The method according to claim 12, wherein: The step of operating the cooking chamber heater continues for at least one hour.

14. The method of claim 11, further comprising circulating a detergent material through the cooking cavity heater and the steam generator.

15. The method of claim 14, further comprising circulating detergent material through a steam generator heater independent of the cooking cavity heater.

16. The method of claim 15, further comprising circulating detergent material through a fan for circulating air to the cooking cavity heater.

17. The method according to claim 11, wherein: The rinse agent is an acetic acid solution.

18. The method according to claim 17, wherein: The acetic acid solution is in the form of tablets or liquid.

19. The method according to claim 18, wherein: The acetic acid solution is a 5% to 10% acetic acid solution.

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