Cooking device with adjustable condensate trap and method for operating a cooking device

Abstract

The invention relates to a cooking appliance (1) with a cooking chamber (3) and a heat exchanger (7), wherein the heat exchanger (7) comprises a discharge device (8) designed for removing steam from the cooking chamber (3) and a supply air duct (9) through which supply air flows, wherein the heat exchanger (7) is designed to transfer heat from the steam flowing through the discharge device (8) to the supply air, and wherein a muffle (4) of the cooking appliance (1) delimiting the cooking chamber (3) has at least one supply air opening (13) through which supply air heated by means of the heat exchanger (7) can be introduced into the cooking chamber (3), wherein the cooking appliance (1) comprises a fan (14) designed to supply an airflow to the heat exchanger (7), and wherein the cooking appliance (1) has at least one adjusting element (15, 16) by means of which it is adjustable what proportion of the airflow passes through the at least one supply air opening. (13) can be placed in the cooking chamber (3),and what proportion of the airflow can be introduced into a sub-compartment (19) of the cooking appliance (1) that is different from the cooking chamber (3). Furthermore, the invention relates to a method for operating the cooking appliance (1).

Description

[0001] The invention relates to a cooking appliance with a cooking chamber and a heat exchanger. The heat exchanger comprises a vent designed for removing steam from the cooking chamber and an air intake duct through which supply air flows. The heat exchanger is designed to transfer heat from the steam flowing through the vent to the supply air. A muffle of the cooking appliance, which delimits the cooking chamber, has at least one air intake opening through which supply air heated by the heat exchanger can be introduced into the cooking chamber. Furthermore, the invention relates to a method for operating such a cooking appliance.

[0002] US Patent 2015 / 0047812 A1 describes an oven with a counterflow heat exchanger. The heat exchanger has an outflow air path from the oven's cooking chamber and an inflow air path through which air from the oven's surroundings can enter the cooking chamber. During oven operation, heat is transferred from the outflow air path to the inflow air path by means of the heat exchanger. The air heated by the heat exchanger, which flows through the inflow air path, enters the cooking chamber.

[0003] The oven described in US 2015 / 0047812 A1 is not very flexible with regard to the use of the heat exchanger.

[0004] The object of the present invention is to create a cooking appliance of the type mentioned at the outset in which the heat exchanger can be operated with particular flexibility, and to provide a corresponding method for operating the cooking appliance.

[0005] This problem is solved by a cooking appliance with the features of claim 1 and by a method with the features of claim 15. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims and in the following description.

[0006] The cooking appliance according to the invention comprises a cooking chamber and a heat exchanger, the heat exchanger comprising a vent designed for removing steam from the cooking chamber and a supply air duct through which supply air flows. The heat exchanger is designed to transfer heat from the steam flowing through the vent to the supply air. A muffle of the cooking appliance, delimiting the cooking chamber, has at least one supply air opening through which supply air heated by the heat exchanger can be introduced into the cooking chamber. The cooking appliance includes a fan designed to supply an airflow to the heat exchanger. Furthermore, the cooking appliance has at least one control element by means of which it is possible to adjust what proportion of the airflow can be introduced into the cooking chamber through the at least one supply air opening and what proportion of the airflow can be introduced into a compartment of the cooking appliance other than the cooking chamber.

[0007] Only a portion of the total airflow with which the fan imparts air to the heat exchanger during operation is introduced into the cooking chamber via at least one air inlet. Another portion of the airflow, which is instead directed into the compartment of the cooking appliance separate from the cooking chamber, can be used in various ways, depending on the preferred operating objective of the heat exchanger.

[0008] If the airflow first passes through the supply air duct of the heat exchanger and then the proportion of the airflow which is introduced into the cooking chamber via the at least one supply air opening is adjusted by means of the control element, a particularly intensive drying and cooling of the steam which flows through the exhaust device during operation of the heat exchanger can be achieved.

[0009] And if, by means of at least one control element, it is set so that a large proportion of the airflow conveyed by the fan is introduced directly into the compartment of the cooking appliance separate from the cooking chamber, and thus does not pass through the heat exchanger at all, then the remaining portion of this airflow can be heated particularly effectively by the heat of the steam. This remaining portion of the airflow then enters the cooking chamber through at least one air inlet. This is advantageous with regard to a very thorough preheating of the incoming air introduced into the cooking chamber through at least one air inlet.

[0010] The at least one control element allows the user to adjust whether the primary goal is to achieve maximum heating of the incoming air or maximum condensation, thus dehumidifying or drying the steam. Because the fan is capable of providing a larger airflow during operation than is intended for supplying air to the cooking chamber via the at least one air inlet, the heat exchanger is particularly flexible in its operation. The at least one control element is preferably designed for stepless adjustment of the respective proportion.

[0011] The recovery of heat contained in the cooking steam and its transfer to the incoming air advantageously increases the energy efficiency of the cooking appliance during operation. Furthermore, the significant reduction in the steam's moisture content, achievable through the heat exchanger, allows for the extraction of exhaust air from the cooking appliance with a particularly low humidity level. This enables the treated steam—that is, the dried or at least less humid and cooled steam—to be transported out of the cooking appliance with a conveniently small exhaust airflow. Since a small exhaust airflow is sufficient to remove the steam with its significantly reduced water content, very little waste heat is released during the extraction process. This, too, contributes to lower energy consumption during operation of the cooking appliance.

[0012] The ability to significantly reduce the moisture content of the cooking steam using the heat exchanger effectively avoids problems that can arise from removing moist steam from the cooking appliance. In particular, damage to components such as at least one of the appliance's control units due to exposure to moist steam can be largely prevented. This is advantageous for the reliable operation of the cooking appliance. Specifically, it prevents condensate from accumulating in a separate compartment of the cooking appliance, such as a control unit. This significantly reduces the risk of damage to components located in such a control unit, especially electrical and / or electronic components, caused by condensate. This is a significant advantage.

[0013] In particular, if it is possible to switch between maximizing air preheating and maximizing condensation by actuating at least one control element, the user of the cooking appliance and / or a control unit or similar control device of the cooking appliance can achieve a very favorable process control with regard to the performance of the cooking appliance and / or the energy consumption of the cooking appliance.

[0014] At least one actuating element can be arranged at an air supply inlet of the heat exchanger, wherein the actuating element is designed to divide the airflow into a first partial flow, which can be introduced into the air supply duct of the heat exchanger, and a second partial flow. The second partial flow can be introduced into the compartment of the cooking appliance, separate from the cooking chamber, bypassing the air supply duct. By actuating the actuating element arranged at the air supply inlet of the heat exchanger, which can be designed, for example, as a flap, a slide, a valve, or the like, the second partial flow can be diverted around the air supply duct of the heat exchanger. The heat from the steam is transferred only to the first partial flow, which flows through the air supply duct of the heat exchanger during operation.This allows for a very strong preheating of the incoming air, which is introduced into the cooking chamber through at least one air inlet. This is particularly advantageous to prevent uneven browning of the food, which could otherwise result from the introduction of insufficiently preheated air into the cooking chamber.

[0015] Additionally or alternatively, at least one actuating element can be arranged at an air supply outlet of the heat exchanger. In this case, the at least one actuating element is designed to direct a first partial flow of air leaving the air supply duct of the heat exchanger to the at least one air supply opening and to introduce a second partial flow into the compartment of the cooking appliance that is different from the cooking chamber.

[0016] By means of the actuator located at the supply air outlet of the heat exchanger, which can be provided, for example, by a flap, a slide, a valve, or the like, the second portion of the supply air flow leaving the heat exchanger can be diverted into a compartment of the cooking appliance separate from the cooking chamber, while only the first portion enters the cooking chamber. In this operating mode of the actuator, the primary function is to reduce condensation and thus the humidity of the steam flowing through the heat exchanger. Because a large supply air flow passes through the heat exchanger's supply air duct, a particularly large amount of heat from the steam can be absorbed by the supply air flowing through the heat exchanger's supply air duct. This allows the steam to be cooled to a significant degree and, due to the associated condensation, dried.

[0017] Preferably, the heat exchanger comprises at least one section of the exhaust device, wherein the at least one section is arranged within the supply air duct. This arrangement of the exhaust device section within the supply air duct allows the supply air flowing through the duct to flow around this section of the exhaust device during operation of the heat exchanger. This promotes efficient heat transfer from the fumes to the supply air.

[0018] During operation of the heat exchanger, the flow of steam through at least the section of the exhaust system and the supply air through the supply air duct can be configured, particularly in counterflow. However, it is also possible for the steam and supply air to flow through the heat exchanger in a parallel flow arrangement and / or a cross-flow arrangement. This allows for optimal adaptation to the specific structural conditions of the cooking appliance.

[0019] To improve heat transfer via the heat exchanger, a variety of measures can be implemented. For example, the shape of the section can be designed to ensure a comparatively long flow path for the steam through the heat exchanger and / or a particularly large internal surface area of ​​the section over which the steam flows during operation. This can be achieved, for instance, by designing the section as a flat and wide pipe. However, a long flow path can also be provided with a round cross-section of the section or pipe, for example, by a meandering shape. Additionally or alternatively, the section can have a multitude of separate flow channels to provide a large surface area over which the steam flows during operation.The flow channels for the supply air can be adjoined in the heat exchanger by additional flow channels for the steam.

[0020] In this case, it is preferably omitted that the inner surface of the section be structured in order to prevent the formation of corresponding structures or patterns during operation of the heat exchanger that would increase the inner surface area of ​​the section. Such clogging can be caused, in particular, by a fat content contained in the steam.

[0021] Preferably, the at least one section has a plurality of elements for increasing its outer surface area. Such elements, which can be exposed to the flow of supply air during operation of the heat exchanger, can be designed, for example, as fins, louvers, fins, pins, or the like. With such an increase in the outer structure of the section, it is advantageous that the elements do not become clogged due to fats or similar substances contained in the steam. This is advantageous.

[0022] It has also proven advantageous to arrange an air filter upstream of at least one section of the supply air duct, viewed in the direction of airflow. This largely prevents clogging of the elements designed to increase the outer surface area of ​​the section, which could be caused, for example, by dust or similar substances contained in the supply air. This is beneficial.

[0023] Preferably, the air filter should be removable from the cooking appliance by the user. Such an arrangement of the air filter within the cooking appliance, allowing easy access for the user, is advantageous. This allows the user to remove and clean the air filter from time to time. Easy access to the air filter makes this particularly easy to implement.

[0024] Preferably, a cooling fan is arranged in the compartment of the cooking appliance that is separate from the cooking chamber. The cooling fan is designed to convey steam cooled by the heat exchanger into the surrounding area of ​​the cooking appliance. Operating the cooling fan allows for the reliable and demand-based removal of cooled and / or dried steam from the cooking appliance. Furthermore, the cooling fan can generate an airflow within the cooking appliance, which can be used to cool, for example, electrical and / or electronic components of the cooking appliance.

[0025] Preferably, the fan designed to supply the heat exchanger with airflow can be operated independently of the cooling fan. This allows for highly demand-oriented adjustment of the heat exchanger operation and the removal of steam from the cooking appliance into its surroundings.

[0026] Preferably, the exhaust device comprises a section arranged downstream of the heat exchanger in the direction of steam flow through the exhaust device, wherein the section is located within the sub-compartment of the cooking appliance that is separate from the cooking chamber. This allows further cooling of the steam to occur in this section. This is advantageous with regard to effective dehumidification of the steam.

[0027] Preferably, the section of the exhaust system located downstream of the heat exchanger can be supplied with cooling air delivered by the cooling fan. This allows the cooling air delivered by the cooling fan to be used in this section of the exhaust system, which is connected to the heat exchanger, to further cool the fumes. This advantageously leads to a particularly thorough condensation of the moisture contained in the fumes.

[0028] Preferably, the cooking appliance has a condensate collection device at a steam outlet of the exhaust system. This allows the condensate obtained by cooling the steam to be collected in a targeted manner at a location where there is no risk of it damaging components of the cooking appliance. This is advantageous. The collection device can, for example, be designed as a basin, an indentation in a component of the cooking appliance, a tank, or the like. This makes the collection device particularly easy to implement.

[0029] Preferably, the collection device is connected via a pipe to a container designed to hold a larger quantity of condensate than the collection device itself. This allows the collection device to occupy relatively little space while still capturing a large amount of condensate within the cooking appliance. Furthermore, this arrangement ensures that the container is positioned in a location within the cooking appliance where sufficient space is readily available.

[0030] Preferably, the container is designed to be emptied by a user of the cooking appliance. For this purpose, it may be provided that the user removes the container from the cooking appliance. Additionally or alternatively, the container may have an outlet that the user can open to empty it. In both cases, it is advantageous that after emptying the container, a comparatively large amount of condensate can be retained within the cooking appliance.

[0031] Preferably, the cooking appliance has an air duct through which air can be supplied to the suction side of the fan. The air duct's inlet is located above a door of the cooking appliance, which is designed to close the cooking chamber. Furthermore, the air duct's inlet communicates with a flow path formed between the door's glass panes.

[0032] This is based on the understanding that the oven door can heat up during operation. This can lead to air flowing through the airflow path or space formed between the door panes. Because this airflow path communicates with the air duct inlet, at least some of this preheated air between the door panes can be used to supply air to the fan's intake side. If the air supplied to the fan's intake side via the door is already preheated, a particularly high temperature can be achieved in the air entering the oven through the at least one air inlet. This is because the air drawn in by the fan can be further heated by the heat exchanger.

[0033] It has proven further advantageous if the cooking appliance has an air guide through which air can be supplied to the suction side of the fan, with the air originating from a control compartment of the cooking appliance. This is based on the understanding that the air in the control compartment of the cooking appliance is usually cooler than in other parts of the appliance that are closer to the cooking chamber and / or are not cooled by the cooling fan. Therefore, by using air from the control compartment of the cooking appliance as the air supplied to the suction side of the fan, a particularly strong cooling of the steam in the heat exchanger can be achieved. This is advantageous with regard to the extensive condensation of moisture contained in the steam.

[0034] Preferably, the cooking appliance has a switching device by which it can be set whether the air is supplied to the fan's intake side primarily via the air duct or primarily via the air guide. This switching device thus allows for a very precise reduction in the cooking appliance's energy consumption or a particularly thorough dehumidification of the steam, depending on the requirements. To reduce energy consumption, the air supplied to the fan's intake side can be drawn primarily via the air duct, which communicates with the airflow path formed between the door panes. Conversely, if particularly thorough dehumidification of the steam is desired, the air supplied to the fan's intake side can be drawn from the cooking appliance's control compartment.

[0035] Finally, it has proven advantageous if the exhaust system includes at least one recirculation device through which steam originating from the cooking chamber can be returned to the cooking chamber. This allows for particularly extensive control over the process air in the cooking chamber. For example, the recirculation device can include an outlet formed within the exhaust system through which steam from the exhaust system can be added to the supply air, which is then introduced into the cooking chamber through at least one supply air opening during operation of the cooking appliance. Additionally or alternatively, the cooking chamber can have a steam inlet through which the recirculated steam can be introduced into the cooking chamber.

[0036] In particular, if the recirculation device can be controlled flexibly, for example by changing a flowable cross-section of the outlet formed in the exhaust device and / or the vapor inlet, the recirculation of vapors can be adjusted and, in particular, regulated with particular precision.

[0037] In the inventive method for operating a cooking appliance with a cooking chamber and a heat exchanger, the heat exchanger comprises a discharge device designed for removing steam from the cooking chamber and a supply air duct through which supply air flows. Heat from the steam flowing through the discharge device is transferred to the supply air by means of the heat exchanger. A muffle of the cooking appliance, which delimits the cooking chamber, has at least one supply air opening through which supply air heated by the heat exchanger is introduced into the cooking chamber. The cooking appliance includes a fan that supplies an airflow to the heat exchanger. Furthermore, the cooking appliance has at least one control element by means of which it is adjusted what proportion of the airflow is introduced into the cooking chamber via the at least one supply air opening and what proportion of the airflow is introduced into a compartment of the cooking appliance other than the cooking chamber.

[0038] By providing at least one actuating element, the heat exchanger can be operated with particular flexibility. Specifically, the operating mode of the heat exchanger allows for either maximized preheating of the supply air, which is introduced into the cooking chamber through the at least one supply air opening, or maximized condensation, i.e., the condensation of moisture contained in the steam. This flexible operation of the heat exchanger is advantageous.

[0039] The advantages and preferred embodiments described for the cooking device according to the invention apply analogously to the method according to the invention and vice versa.

[0040] Terms such as "top", "bottom", "front", "back", "horizontal", "vertical", "depth direction", "latitude direction", "height direction" and the like indicate the positions and orientations that would be present when the cooking appliance is used and arranged as intended, and when viewed by an observer standing in front of the cooking appliance and looking towards it.

[0041] The features and combinations of features mentioned above in the description, as well as those subsequently mentioned in the figure description and / or shown in the figures alone, are not only usable in the combinations specified, but also in other combinations or on their own, without departing from the scope of the invention. Thus, embodiments that are not explicitly shown or explained in the figures, but which can be derived and generated from the explained embodiments by separate combinations of features, are also to be considered as encompassed and disclosed by the invention. Thus, embodiments and combinations of features that do not exhibit all the features of an originally formulated independent claim are also to be considered disclosed.Furthermore, embodiments and combinations of features, in particular those set out above, are to be considered disclosed which go beyond or deviate from the combinations of features set out in the cross-references of the claims.

[0042] Further advantages, features and details of the invention will become apparent from the claims, the following description of preferred embodiments, and the drawings. These show: Fig. 1, in a highly schematic perspective view, shows a cooking appliance with a cooking chamber formed within a muffle of the cooking appliance, wherein the cooking chamber can be closed by means of a door of the cooking appliance; Fig. 2, in a schematic sectional view, shows the cooking appliance according to Fig. 1 with the door closed; Fig. 3 shows a partially cutaway perspective view of the cooking appliance in the area of ​​a heat exchanger, by means of which steam extracted from the cooking chamber can be cooled; Fig. 4 shows another schematic and partially cutaway perspective view of the area of ​​the cooking appliance in which the heat exchanger is arranged; Fig. 5 shows a schematic and partial view of the cooking appliance according to Fig. 2 in another variant; Fig. 6 schematically and in part shows the supply of air to a suction side of a fan via an air duct which communicates with a flow path formed in the door of the cooking appliance; and Fig. 7 schematically and in part shows the cooking appliance in which air from a switch compartment of the cooking appliance is supplied to the suction side of the fan.

[0043] In the figures, identical or functionally equivalent elements are provided with identical reference symbols.

[0044] In Fig. 1 A cooking appliance 1 is shown in a highly schematic, perspective view. A cooking chamber 3 is located within a housing 2 of the cooking appliance 1, and this chamber is bounded by a muffle 4 of the cooking appliance 1. The housing 2 separates the cooking appliance 1 from an environment 29 (compare Fig. 2 The cooking chamber 3 is limited by the cooking appliance 1. The cooking chamber 3 can be closed at the front by a door 5 of the cooking appliance 1, with the door 5 being in Fig. 1 shown in a partially open position. In the depth direction x of the cooking appliance 1, the cooking chamber 3 is bounded by a rear wall 6 belonging to the muffle 4. The depth direction x, a width direction y of the cooking appliance 1 (designed, for example, as an oven and / or a steam cooker), and a height direction z of the cooking appliance 1 are shown in Fig. 1 and in Fig. 2 illustrated by a respective coordinate system.

[0045] According to Fig. 2 The cooking appliance 1 comprises a heat exchanger 7, by means of which steam extracted from the cooking chamber 3 can be cooled. The heat exchanger 7 includes a discharge device 8 for extracting steam from the cooking chamber 3 and a supply air duct 9 through which supply air flows. The supply air flowing through the supply air duct 9 is in Fig. 2 Illustrated by a first arrow 10. A further arrow 11 illustrates in Fig. 2 the entry of steam from the cooking chamber 3 into the exhaust device 8 of the heat exchanger 7. Fig. 2 It is evident that the heat exchanger 7 can comprise, for example, a tubular section 12 of the exhaust device 8, wherein the section 12 is arranged within the supply air duct 9. Thus, when supply air flows through the supply air duct 9, this supply air flows around the section 12 of the exhaust device 8. This leads to a cooling of the vapor, which is then expelled by the heat exchanger 7. Fig. 2 through the tubular section 12 of the discharge device 8.

[0046] The heat exchanger 7 is very flexible in its operation. In particular, it can be set whether the heat exchanger 7, which can also be used as a condensate trap, is operated in such a way as to produce as much condensate as possible, thus drying the steam particularly thoroughly, or whether the aim is to achieve the greatest possible preheating of the supply air, which can be introduced into the cooking chamber 3 via at least one supply air opening 13. According to the schematic representation in Fig. 2 At least one air inlet opening 13 can be formed in the rear wall 6 of the muffle 4 of the cooking appliance 1.

[0047] The cooking appliance 1 includes a fan 14, which is designed to supply an airflow to the heat exchanger 7. Furthermore, the cooking appliance 1 has at least one control element 15, 16, by means of which it is possible to adjust what happens to the total airflow supplied by the fan 14. For example, the cooking appliance 1 can include the first control element 15 and the second control element 16, which are arranged in Fig. 2 are merely presented in a highly schematic way.

[0048] By means of the first actuating element 15, which is arranged at an air supply inlet 17 of the heat exchanger 7 (compare Fig. 5 The airflow delivered by fan 14 can be divided. Specifically, the total airflow delivered by fan 14 can be divided into a first partial flow, which can be introduced into the supply air duct 9 of the heat exchanger 7. This first partial flow is in Fig. 2 and in Fig. 5 as illustrated by arrow 10. The first actuating element 15 divides the total airflow conveyed by the fan 14 into this first partial flow, which can be introduced into the supply air duct 9, and into a second partial flow 18, which is in Fig. 2 and in Fig. 5 This is illustrated by a further arrow. This second partial flow 18 bypasses the supply air duct 9 and enters a sub-compartment 19 of the cooking appliance 1, which is different from the cooking chamber 3. For example, this sub-compartment 19 can be designed as a switch compartment of the cooking appliance 1, i.e., as a sub-compartment 19 in which at least one electrical and / or electronic component of the cooking appliance 1 is housed, for example in the form of at least one control unit or the like.

[0049] In particular, the first adjusting element 15 can be used to set the airflow so that only a small portion of the total airflow delivered by the fan 14 enters the supply air duct 9 of the heat exchanger 7, while the larger portion or partial flow 18 enters the compartment 19, specifically the control compartment, of the cooking appliance 1. In this case, a comparatively small amount of the total airflow delivered by the fan 14 flows through the supply air duct 9 of the heat exchanger 7. This first, small partial flow, which enters the supply air duct 9 of the heat exchanger 7, is then used to control the airflow. Fig. 2 As illustrated by arrow 10, the steam heats the air very strongly. Consequently, comparatively preheated air flows into the cooking chamber 3 through the air inlet 13. With this setting of the first control element 15, preheating the air is therefore the primary focus. The first control element 15 can be designed, for example, as a valve, flap, or slider. A sliding movement of the first control element 15 is possible in Fig. 2 and in Fig. 5 schematically indicated by a double arrow 20.

[0050] Additionally or alternatively, the cooking appliance 1 can be used in Fig. 2 and in Fig. 5 The second actuating element 16, shown schematically, is arranged at a supply air outlet 21 of the heat exchanger 7. The second actuating element 16 is designed to supply a first partial flow 23 from a supply air stream 22 leaving the supply air duct 9 of the heat exchanger 7 to the supply air opening 13. This first partial flow 23 is in Fig. 5 illustrated by a curved arrow. A second partial flow 24 of the supply air flow 22 leaving the supply air duct 9 is in Fig. 5 This is illustrated by another curved arrow. This second partial current 24 enters the sub-compartment 19 of the cooking appliance 1, which is designed, for example, as the switch compartment of the cooking appliance 1.

[0051] The second actuating element 16 can also be designed as a flap and / or as a slide and / or as a valve or the like. Fig. 2 and in Fig. 5 The second actuating element 16 is shown schematically as a flap, which, depending on its position, adjusts the size of the first partial flow 23 supplied to the supply air opening 13 and the size of the second partial flow 24 entering the compartment 19. By dividing the supply air flow 22 after it has passed through the heat exchanger 7, a very large portion of the total airflow delivered by the fan 14, in particular the entire airflow delivered by the fan 14, can be used to cool the vapors flowing through the section 12 of the exhaust device 8. This allows for a very thorough drying of the vapors.

[0052] Out of Fig. 3 The arrangement of the section 12 of the exhaust device 8, through which the steam flows, within the supply air duct 9 is shown schematically. Arrow 11 illustrates the steam entering section 12 from the cooking chamber 3. The fan 14, which supplies the heat exchanger 7 with the airflow, is also shown. Arrow 10 illustrates the first partial flow, which enters the supply air duct 9 of the heat exchanger 7. A further arrow illustrates the second partial flow 18, which bypasses the supply air duct 9 and enters the compartment 19 of the cooking appliance 1, which is designed here as a control compartment. The first actuating element 15 is located in Fig. 3 For the sake of clarity, it is not shown in detail. However, arrow 10 and the partial flow 18 illustrate how the first actuating element 15 divides the airflow delivered by the fan 14 at the supply air inlet 17 (compare Fig. 5 ) of the heat exchanger 7 can be carried out.

[0053] Likewise, in Fig. 3 The second actuating element 16 is not shown, but the first partial flow 23, which passes through the supply air opening 13 (compare) is indicated by an arrow. Fig. 2 ) can enter cooking chamber 3, and, through a further arrow, the second partial current 24, which can enter partial chamber 19 or switch chamber of the cooking appliance 1. From Fig. 3 It is evident that the vapor is guided through the inner channel of the heat exchanger 7.

[0054] A pipe section 25 serving as an inlet to section 12, which extends from a ceiling 36 of the muffle 4 (compare Fig. 2 The pipe section 25, which leads essentially upwards in the vertical direction z of the cooking appliance 1 and through which the steam can be supplied to the heat exchanger 7, is preferably not oriented exactly vertically. Rather, the pipe section 25 (as shown in Fig. 2 (shown schematically) is oriented obliquely with respect to a plane spanned by the depth direction x and the width direction y. This largely prevents the backflow of condensate that forms early on from the pipe section 25 into the cooking chamber 3.

[0055] The steam originating from cooking chamber 3 is guided through the inner channel of the heat exchanger 7. This inner channel can be accessed through the Fig. 2 schematically represented section 12 or by the in Fig. 3 The component of the heat exchanger 7, represented as a pipe, is provided. The cross-sectional area through which air flows in the inner section 12 and the outer supply air duct 9 can be round and / or rectangular, or have a more complex, in particular polygonal, shape. The supply air flows around the inner section 12, and heat is transferred from the vapor to the supply air during this process.

[0056] Depending on whether the first actuator is 15 or the second actuator is 16 (compare Fig. 2 ) is used, it is possible to adjust what proportion of the total airflow conveyed by the fan 14 enters the cooking chamber 3 via the air intake opening 13 (compare Fig. 2 ) and what proportion of the total airflow conveyed by the fan 14 enters the sub-compartment 19 of the cooking appliance 1, which is different from the cooking chamber 3. The at least one actuating element 15, 16 is preferably controllable by a control device (not shown) of the cooking appliance 1.

[0057] In Fig. 4 Actuators 15 and 16 are not shown. However, even in Fig. 4 The partial flow 18 is indicated by a curved arrow; this flow can be diverted before entering the heat exchanger 7 using the first actuating element 15, in order to reach the sub-chamber 19. A further curved arrow indicates... Fig. 4 The partial flow 23 illustrates which can be diverted using the second actuating element 16 in order to exit the heat exchanger 7 and enter the supply air opening 13 (compare Fig. 2 ) to be supplied.

[0058] Out of Fig. 4 It is further evident that a collecting device 27, which serves to collect condensate, can be arranged at a vapor outlet 26 of the discharge device 8. The vapor outlet 26 can be designed as a vapor outlet of the heat exchanger 7. The vapor leaving the vapor outlet 26 is cooled and contains less moisture than vapor which exits via the pipe section 25 (compare Fig. 3 ) enters the heat exchanger 7. This cooled and less humid air from the cooking chamber 3 can be distributed into the surroundings 29 by means of a cooling fan 28 of the cooking appliance 1 (compare Fig. 2 The cooling fan 28 is also shown in the schematic diagram of the cooking appliance 1. Fig. 2 shown.

[0059] The collecting device 27, which can be designed, for example, as a basin or tub, is also shown schematically in the diagram in Fig. 5 As indicated. The condensate accumulating in the collection device 27 can be conveyed via a line 30, for example in the form of a pipe, a hose or the like, to a container 31, which can be designed as a wastewater tank of the cooking appliance 1 that can be emptied by a user of the cooking appliance 1. The container 31 is in Fig. 5 schematically indicated, whereby the location of the container 31 in the cooking appliance 1 is not realistically depicted.

[0060] From a comparison of the in Fig. 2 and in Fig. 5 As can be seen in the illustrated variants of the cooking appliance 1, the exhaust device 8 can have a section 32, which is arranged downstream of the heat exchanger 7 and which extends through the sub-chamber 19 of the cooking appliance, separate from the cooking chamber 3. This extension of the airflow for cooling the steam results in a particularly long heat-emitting surface of the exhaust device 8. This advantageously leads to an increased amount of condensate. Preferably, the steam flow through section 32 is designed such that section 32 is located in a region of the control chamber or sub-chamber 19 where, during operation of the cooking appliance 1, good airflow with the cooling air supplied by the cooling fan 28 can be achieved.

[0061] To improve the transfer of heat from the steam to the supply air, section 12 can be provided with elements (not shown in detail here) that increase the outer surface area of ​​section 12. For example, such elements can be designed as louvers and / or fins and / or pins or the like.

[0062] To prevent dust or similar contaminants from the supply air from settling on these elements, an air filter 44 can be arranged upstream of section 12 (compare Fig. 5 Preferably, the air filter 44 can be removed from the cooking appliance 1 by a user of the cooking appliance 1.

[0063] Depending on the origin of the air drawn in by the fan 14, the heat exchanger 7, which serves as a condensate trap, can be used either to heat the supply air introduced into the cooking chamber 3 via the air inlet 13 to a particularly high degree, or to condense a particularly large amount of water from the steam. These different objectives can be accommodated to a greater extent by adjusting the direction from which the air is drawn in from one suction side 33 (see figure). Fig. 6 ) of the fan 14 supplied air.

[0064] In Fig. 6 One variant is shown in which air is supplied to the suction side 33 of the fan 14 via an air duct 34, the air duct 34 being located above the ceiling 36 of the cooking chamber 3 (compare Fig. 2 ) is arranged. Fig. 2 It is evident that an inlet 35 of the air duct 34 is arranged above the door 5 of the cooking appliance 1, which is designed to close the cooking chamber 3. When the door 5 is closed, the inlet 35 communicates with a flow path 37, which is formed between the panes 38 and 39 of the door 5. For example, the flow path 37 can be formed between a first pane 38, closer to the surroundings 29, and a second pane 39 of the door 5, closer to the cooking chamber 3.

[0065] During operation of the cooking appliance 1, air in the space formed between the discs 38 and 39 can heat up. This heated air can then flow via the flow path 37 formed between the discs 38 and 39 to the inlet 35 of the air duct 34. Fig. 6 A switching device designed as flap 40 is shown schematically. In the Fig. 6 In the position shown, flap 40 allows air from door 5 to flow to the suction side 33 of the fan 14. As a result, the air supplied to the suction side 33 of the fan 14 is comparatively warm.

[0066] In Fig. 7 In contrast, flap 40 is shown in a second switching position, in which air is supplied to the suction side 33 of the fan 14, which originates from the sub-compartment 19 or switch compartment of the cooking appliance 1. Fig. 7 A schematic representation of part of an air guidance device 41 is shown, which, particularly in conjunction with the flap 40, ensures that air is supplied to the suction side 33 of the fan 14 from the switch compartment or sub-compartment 19 of the cooking appliance 1. A corresponding flow arrow 42 is shown in Fig. 7 As shown. Accordingly, the flap 40 blocks the intake side 33 of the fan 14 towards the air duct 34, which communicates with the flow path 37 formed between the panes 38, 39 of the door 5. In Fig. 6 In contrast, another flow arrow 43 illustrates the flow of air, which is supplied to the suction side 33 of the fan 14, towards the suction side 33 of the fan 14 via the air duct 34 from the door 5.

[0067] The air coming from sub-room 19 or switch room is cooler than the air coming from door 5. Therefore, in the context of Fig. 7 The operation of cooking appliance 1 explained that a particularly thorough removal of water from the steam is achieved. And in the section with reference to Fig. 6 In contrast to the described operation of the cooking appliance 1, the supply air can be heated particularly strongly, which enters the cooking chamber 3 via the supply air opening 13 (compare Fig. 2 ) arrived.

[0068] A switching device can be provided by means of at least one flap 40, by means of which it can be set whether the air is supplied to the suction side 33 of the fan 14 at least predominantly via the air duct 34 or at least predominantly via the air guide device 41. This allows for particularly flexible process control, which can be set either with regard to reducing the energy consumption of the cooking appliance 1 or with regard to maximizing the performance with regard to dehumidifying the steam.

[0069] To achieve good air distribution in the cooking chamber 3, the cooking appliance 1 can include a cooking chamber fan 45, the fan wheel 46 of which is arranged in the cooking chamber 3 (compare Fig. 2 ). For example, a drive unit 47 of the oven fan 45, designed as an electric motor, is in Fig. 2 as also indicated. The fan wheel 46 can be arranged behind a (not shown) shielding plate or similar shielding device when viewed in the depth direction x of the cooking appliance 1. This ensures that the fan wheel 46 is not accessible to a user reaching into the cooking chamber 3.

[0070] In Fig. 2 Furthermore, a recirculation device 48 is indicated, via which steam originating from the cooking chamber 3 can be recirculated back into the cooking chamber 3. The recirculation device 48 can be configured according to Fig. 2 The recirculation device 48 comprises a duct that opens into the cooking chamber 3. Additionally or alternatively, the recirculation device 48 can include a duct through which steam can be mixed with the supply air before a mixture of supply air and steam enters the cooking chamber 3 via the supply air opening 13. Preferably, the recirculation of steam into the cooking chamber 3, which can be effected by means of the recirculation device 48, is adjustable, and in particular controllable, by a control device (not shown) of the cooking appliance 1.

[0071] The heat exchanger 7, which also serves as a condensate trap, allows a portion of the energy contained in the steam to be recuperated or recovered and transferred to the supply air that is to be introduced into the cooking chamber 3. Furthermore, the heat exchanger 7 enables efficient removal of excess moisture from the cooking chamber 3. The provision of at least one control element 15, 16 allows for particularly flexible operation of the heat exchanger 7 with regard to the amount of condensate produced or the preheating of the supply air introduced into the cooking chamber 3 via the supply air opening 13. Bezugszeichenliste

[0072] 1 Cooking appliance 2 Housing 3 Cooking chamber 4 Muffle 5 Door 6 Rear wall 7 Heat exchanger 8 Exhaust device 9 Air supply duct 10 Arrow 11 Arrow 12 Section 13 Air supply opening 14 Fan 15 Actuator 16 Actuator 17 Air supply inlet 18 Partial flow 19 Partial chamber 20 Double arrow 21 Air supply outlet 22 Air supply flow 23 Partial flow 24 Partial flow 25 Pipe section 26 Vapor outlet 27 Collector 28 Cooling fan 29 Surroundings 30 Duct 31 Container 32 Section 33 Suction side 34 Air shaft 35 Inlet 36 Ceiling 37 Flow path 38 Disc 39 Disc 40 Flap 41 Air guide device 42 Flow arrow 43 Flow arrow 44 Air filter 45 Oven fan 46 Fan wheel 47 Drive unit 48 Return unit

Claims

1. Cooking appliance (1) with a cooking chamber (3) and with a heat exchanger (7), wherein the heat exchanger (7) comprises a discharge device (8) designed for removing steam from the cooking chamber (3) and a supply air duct (9) through which supply air flows, wherein the heat exchanger (7) is designed to transfer heat from the steam flowing through the discharge device (8) to the supply air, and wherein a muffle (4) of the cooking appliance (1) delimiting the cooking chamber (3) has at least one supply air opening (13) through which supply air heated by means of the heat exchanger (7) can be introduced into the cooking chamber (3), characterized by the fact thatthe cooking appliance (1) comprises a fan (14) which is designed to supply an airflow to the heat exchanger (7), wherein the cooking appliance (1) has at least one actuating element (15, 16) by means of which it is possible to adjust what proportion of the airflow can be introduced into the cooking chamber (3) via the at least one air inlet opening (13), and what proportion of the airflow can be introduced into a sub-chamber (19) of the cooking appliance (1) different from the cooking chamber (3).

2. Cooking appliance (1) according to claim 1, characterized by the fact that at least one actuating element (15) is arranged at an air supply inlet (17) of the heat exchanger (7), wherein the actuating element (15) is designed to divide the airflow into a first partial flow (10) that can be introduced into the air supply duct (9) of the heat exchanger (7) and into a second partial flow (18), wherein the second partial flow (18) can be introduced into the partial space (19) of the cooking appliance (1) that is different from the cooking chamber (3), bypassing the air supply duct (9).

3. Cooking appliance (1) according to claim 1 or 2, characterized by the fact that the at least one actuating element (16) is arranged at an air supply outlet (21) of the heat exchanger (7), wherein the actuating element (16) is designed to supply a first partial flow (23) from an air supply duct (9) of the heat exchanger (7) to the at least one air supply opening (13) and to introduce a second partial flow (24) into the partial space (19) of the cooking appliance (1) that is different from the cooking chamber (3).

4. Cooking appliance (1) according to one of the preceding claims, characterized by the fact that the heat exchanger (7) comprises at least one section (12) of the exhaust device (8), wherein the at least one section (12) is arranged within the supply air duct (9).

5. Cooking appliance (1) according to claim 4, characterized by the fact thatthe at least one section (12) has a plurality of elements for increasing an outer surface area of ​​the at least one section (12), wherein, viewed in the direction of the airflow through the supply air duct (9), an air filter (44) is arranged upstream of the at least one section (12), which can be removed from the cooking appliance (1) by a user of the cooking appliance (1).

6. Cooking appliance (1) according to one of the preceding claims, characterized by the fact that In the sub-chamber (19) of the cooking appliance (1) which is separate from the cooking chamber (3) a cooling fan (28) is arranged, which is designed to convey vapors cooled by means of the heat exchanger (7) into an environment (29) of the cooking appliance (1).

7. Cooking appliance (1) according to one of the preceding claims, characterized by the fact thatthe exhaust device (8) comprises a section (32) arranged downstream of the heat exchanger (7) in the direction of flow of steam through the exhaust device (8), which is arranged within the sub-space (19) of the cooking appliance (1) that is different from the cooking chamber (3).

8. Cooking appliance (1) according to claims 6 and 7, characterized by the fact that The section (19) of the discharge device (8) located downstream of the heat exchanger (7) can be supplied with cooling air conveyed by the cooling fan (28).

9. Cooking appliance (1) according to one of the preceding claims, characterized by the fact that the cooking appliance (1) has a collection device (27) for collecting condensate at a vapor outlet (26) of the exhaust device (8).

10. Cooking appliance (1) according to claim 9, characterized by the fact thatthe collecting device (27) is connected via a line (30) to a container (31) which can be emptied, in particular by a user of the cooking appliance (1) and which is designed to receive a larger quantity of condensate than the collecting device (27).

11. Cooking appliance (1) according to one of the preceding claims, characterized by the fact that the cooking appliance (1) has an air duct (34) through which air can be supplied to a suction side (33) of the fan (14), wherein an inlet (35) of the air duct (34) is arranged above a door (5) of the cooking appliance (1), which is designed to close the cooking chamber (3), and wherein the inlet (35) of the air duct (34) communicates with a flow path (37) which is formed between panes (38, 39) of the door (5).

12. Cooking appliance (1) according to one of the preceding claims, characterized by the fact thatthe cooking appliance (1) has an air guidance device (41) through which air can be supplied to a suction side (33) of the fan (14), which originates from a switch room of the cooking appliance (1).

13. Cooking appliance (1) according to claims 11 and 12, characterized by the fact that the cooking appliance (1) has a switching device (40) by means of which it is possible to adjust whether the air can be supplied to the suction side (33) of the fan (14) at least predominantly via the air duct (34) or at least predominantly via the air guide device (41).

14. Cooking appliance (1) according to one of the preceding claims, characterized by the fact that the exhaust device (8) comprises at least one return device (48) via which steam originating from the cooking chamber (3) can be returned to the cooking chamber (3).

15. Method for operating a cooking appliance (1) with a cooking chamber (3) and with a heat exchanger (7), wherein the heat exchanger (7) comprises a discharge device (8) designed for removing steam from the cooking chamber (3) and a supply air duct (9) through which supply air flows, wherein heat from the steam flowing through the discharge device (8) is transferred to the supply air by means of the heat exchanger (7), and wherein a muffle (4) of the cooking appliance (1) delimiting the cooking chamber (3) has at least one supply air opening (13) through which supply air heated by means of the heat exchanger (7) is introduced into the cooking chamber (3), characterized by the fact thatthe cooking appliance (1) comprises a fan (14) which supplies an airflow to the heat exchanger (7), wherein the cooking appliance (1) has at least one control element (15, 16) by means of which it is set what proportion of the airflow is introduced into the cooking chamber (3) via the at least one air inlet opening (13), and what proportion of the airflow is introduced into a sub-chamber (19) of the cooking appliance (1) different from the cooking chamber (3).

Images