EP1050718A2 - Oven with removing fumes and fresh air addition system. - Google Patents

Abstract

The oven has an oven casing (10) whose wall (14,17) encloses the cooking chamber (15) and at least one vapour outlet (18), p in the casing top. A fan (2) mounted outside the casing wall has at least one suction region (26) connected to the vapour outlet opening and at least one outlet region (28). A fresh air duct (8) has ends opening into the exterior and into the suction region outlet duct (5) has ends opening into the fan's output region and into the exterior for outputting a mixture of vapour from the and fresh air. An Independent claim is also included for a method of extracting vapour from an oven chamber enclosed by a casing wall.

Description

The invention relates to a cooking oven (baking and roasting oven) and a method for removing vapors (cooking vapors, cooking vapors) from one enclosed by a muffle wall Cooking space (muffle interior) of a cooking oven.

A cooking oven is known from DE 33 46 019 C2 , in which the oven muffle can be heated both by electric radiant heaters (top heat and bottom heat) and by a microwave generator. On its muffle top, the furnace muffle has a vapor opening in a front area facing the door, in which a catalytic afterburner in the form of a porous vapor stone is arranged. Above the vapor opening there is a fan wheel with fan blades pointing downwards towards the vapor opening, which is arranged in a suction chamber enclosed by a fan housing and, as a radial fan, sucks the air passing through the vapor stone axially out of the muffle interior and blows it out radially through a lateral outlet opening in the fan housing . The fan wheel is driven via an axis by an electric drive motor which is only switched on when the microwave generator is in operation. Furthermore, an air inlet opening is provided below the furnace door, through which air can flow into the interior of the muffle. The furnace muffle is surrounded by cooling air ducts, and in the upper area of a vertical cooling air duct located behind the furnace muffle there is a cooling air blower, which draws in the heated air in the vicinity of the furnace muffle and through a ventilation duct running horizontally above the furnace muffle through an outlet opening above the furnace door blows outside in front. The outlet opening of the vapor suction fan also opens into this ventilation channel, so that the vapor extracted and cleaned by the catalyst is blown out to the front with the cooling air. Condensation of vapors on the inside of the furnace door is prevented by the air flow along the furnace door that arises within the muffle. The vapor suction fan only sucks vapors from the furnace muffle from the interior of the muffle, but not cooling air from the surroundings of the furnace muffle.

DE 35 16 847 C2 discloses a cooking oven with electric convection heating and electric radiation heating in the oven muffle. A vapor extraction opening is provided in the muffle ceiling, into which an externally heated catalyst is inserted. Above the vapor extraction opening, a blower chamber is arranged outside the furnace muffle, in which a double-sided suction radial fan is accommodated. The radial fan comprises an impeller with a cutting disc, which enables suction from the opposite directions. In operation, the radial fan sucks air from below from the furnace muffle through the vapor extraction opening and the catalyst into the blower chamber and from above cooling air from the inside of the device outside the furnace muffle. The fan chamber is connected to the front of the device with two flow channels, which are separated from one another by a flow guide wall at the level of the lower fan wheel part facing the vapor extraction opening. In the remaining areas, the fan chamber is also separated into an upper and a lower part at the level of the lower fan wheel area. As a result, the cooling air sucked in from above is essentially directed only radially into the upper flow channel and completely exhausted to the front, while part of the vapor extracted from the bottom is also introduced into the upper flow channel, but mostly into the lower flow channel and is returned via this flow channel as a return line through an inlet opening in the muffle ceiling into the muffle interior. Energy is saved by recycling the cleaned exhaust air. According to the representation in the single figure of DE 35 16 847 C3 , the radial fan is a drum rotor.

A cooking oven with an integrated microwave part is known from DE 38 39 657 C2 . This known cooking oven has a shaft-shaped vapor extraction opening on the muffle ceiling, above which a vapor extraction fan is arranged within a fan housing. The vapor extraction fan comprises an impeller driven by a motor with fan blades directed downwards towards the vapor extraction opening and with openings through which vapors are sucked in both from below from the cooking space (muffle interior) and from above, cool ambient air. For this purpose, the fan housing has an opening on a side facing away from the vapor suction opening, through which the cool ambient air can be sucked in by the fan wheel. In the blower housing of the vapor extraction fan, the vapor sucked in through the vapor extraction opening is mixed with the ambient air and blown out through a flow channel radially towards the front of the device. Cooling air also flows into this flow channel from a cooling air blower arranged in a rear oven area via a magnetron, which cooling air blower had sucked in from an air channel in the area of the rear wall of the appliance from a lower area of the cooking oven. Part of the cooling air flow drawn in by the cooling fan is blown into the cooking space via an inlet opening which can be closed by a flap.

DE 42 11 755 A1 discloses a further known cooking oven with an oven muffle which has a vapor extraction opening in the muffle ceiling, and with a radial fan arranged inside a spiral housing, which radially blows cooling air drawn in from below through an air inlet opening from the interior of the housing into a diffuser channel, which Cooling air leads to the front of a device. The vapor extraction opening is connected via a vapor hose to a junction in the diffuser channel. As a result, the vapor is sucked off through the vapor hose and the vapor discharge opening by the cooling air flow generated by the radial fan by the action of an injector due to the dynamic vacuum generated thereby and blown out to the front with the cooling air. In this embodiment, the radial fan does not draw the vapors directly axially.

DE 43 22 360 A1 finally describes a built-in cooker with a cooking oven below a worktop and with a hob arranged in the worktop. An exhaust air opening is provided in the cooktop frame, in which an aspirator driven by an electric motor is arranged. An open end of a tubular vapor channel is arranged at a distance from the exhaust air opening. The vapor channel is connected to a vapor outlet opening in the muffle ceiling of the oven muffle of the oven. During operation, the suction fan sucks vapors from the interior of the muffle as well as air from the side of the interior of the oven above the muffle. It is an axial suction fan that blows the flow in the same direction in which it draws it in.

From EP 0 330 727 A1 a built-in oven is known Cooking chamber of an oven muffle that can be closed by an oven door and one located in the rear area above the oven muffle Cooling air blower. The cooling air blower sucks cooling air through an opening at the bottom of the door from the outside on and through the door interior and through one in the rear Area of the door in the vicinity of the door handle arranged air passage opening in a horizontally above the oven muffle running cooling air intake duct that extends to the negative pressure side of the cooling air fan runs. On the overprint side of the cooling air blower closes a cooling air discharge duct at the above the cooling air intake duct also essentially runs horizontally and through which the cooling air fan the cooling air above the door again at the front of the Blows the oven into the outside space. A discharge of vapors from the cooking chamber is not provided in this known oven.

The invention is based on the object, a special one Cooking oven with a fan for extracting vapors the cooking space (muffle interior) of the oven and a special one Process for removing vapors from the cooking space To specify the oven.

This object is achieved according to the invention with the features of claim 1 and claim 25.

a) eine Ofenmuffel mit einer Wandung (Muffelwandung), die einen Garraum umgibt und wenigstens eine Wrasenaustrittsöffnung aufweist;

b) ein außerhalb der Muffelwandung angeordnetes Gebläse mit wenigstens einem Ansaugbereich, der mit der Wrasenaustrittsöffnung der Muffelwandung in Strömungsverbindung steht, sowie mit wenigstens einem Ausblasbereich;

c) wenigstens einen mit einem Ende in einen Außenraum mündenden und mit einem anderen Ende in den Ansaugbereich des Gebläses mündenden Frischluftkanal;

d) wenigstens einen den Ausblasbereich des Gebläses mit dem Außenraum verbindenden Ausleitkanal (Gasabführkanal, Abluftkanal) zum Ausleiten des Gemischs der vom Gebläse in dessen Betrieb durch die Wrasenaustrittsöffnung aus dem Garraum angesaugten Wrasen (Gardämpfe, Gardünste) einerseits und der durch den Frischluftkanal aus dem Außenraum angesaugten Frischluft andererseits (Abluftgemisch).

The cooking oven, in particular built-in oven, according to claim 1

a) an oven muffle with a wall (muffle wall) which surrounds a cooking space and has at least one vapor outlet opening;

b) a fan arranged outside the muffle wall with at least one suction area, which is in flow connection with the vapor outlet opening of the muffle wall, and with at least one blow-out area;

c) at least one fresh air duct opening at one end into an outside space and at the other end opening into the suction area of the blower;

d) at least one discharge duct (gas discharge duct, exhaust duct) connecting the blower area of the blower to the outside for discharging the mixture of the vapors sucked in by the blower during its operation through the vapor outlet opening from the cooking chamber (cooking vapors, cooking fumes) on the one hand and through the fresh air duct from the outside fresh air drawn in on the other hand (exhaust air mixture).

a) Erzeugen eines Unterdrucks mittels eines außerhalb der Muffelwandung angeordneten Gebläses zum Ansaugen sowohl von Wrasen aus dem Garraum durch eine Wrasenaustrittsöffnung in der Muffelwandung als auch von Frischluft aus einem Außenraum des Garofens (aus dem Freien) durch einen Frischluftkanal und

b) Erzeugen eines Überdruckes mit dem Gebläse zum Ausblasen des Gemischs von angesaugtem Wrasen und Frischluft durch einen Ausleitkanal in den Außenraum.

The method according to claim 25 for discharging vapors from a cooking space of a cooking oven, in particular a built-in oven, enclosed by a muffle wall, comprises the method steps:

a) generating a vacuum by means of a fan arranged outside the muffle wall for sucking in both vapors from the cooking space through a vapor outlet opening in the muffle wall and fresh air from an outside space of the cooking furnace (from the outside) through a fresh air duct and

b) Generating an overpressure with the blower for blowing out the mixture of sucked-in vapors and fresh air through an outlet duct into the outside space.

The invention is based on the consideration given by the vapor outlet opening Vapors extracted in the muffle wall before leaving the market in a defined quantity and type and way to mix with fresh air from the outdoors to reduce the temperature of the vapor on the one hand and on the other hand to dilute the vapors so that deposits and Soiling can be reduced. The fresh air is targeted through at least one fresh air duct to the intake area (Vacuum side) of the blower. By the dimensions of the fresh air duct can be supplied per unit of time Fresh air volume (the volume flow of fresh air) at the given suction power of the blower to the desired size can be set. The relationship too the volume flows of fresh air and vapors to each other can through the dimensioning and arrangement of the fresh air duct in relation to the dimensioning and arrangement of the Vapor outlet opening can be set precisely.

Advantageous further developments and refinements of the cooking oven and the method result from that of claim 1 or claim 25 each dependent claims.

The oven generally has a front the one loading opening of the furnace muffle for loading the loading opening and a Furnace door arranged to close this loading opening are. It now opens in an advantageous embodiment either the fresh air duct or the discharge duct or preferably both on the front of the oven in the outside space. Especially with a built-in oven relatively large volume flows (gas volume per unit of time, gas flow) of the fresh air and / or the exhaust air flow can be achieved. The fresh air duct and / or however, the exhaust air duct can also be connected to one lead to another place, especially at the the rear side (rear side) of the Oven. In a special combination, the fresh air sucked in from the front and the drain to the rear, preferably towards the top, for example to an extractor hood with subsequent chimney, blown out become.

The fresh air duct and the discharge duct run in one preferred embodiment at least predominantly above the oven muffle, preferably essentially horizontal, the discharge duct preferably above the fresh air duct runs. As a result, the particularly heavily heat-loaded Area above the muffle ceiling with the still cool Fresh air is cooled with a compact design. A particularly compact structure is achieved if the Fresh air duct and the discharge duct through a common, preferably plate-shaped, air guide (Air baffle, partition) are separated from each other, so that a second channel wall can be omitted.

The mouth areas of the fresh air duct and discharge duct in the outside space can at least partially within one common mouth area or from each other be separated and offset from each other, especially on the Front side offset from one another, be arranged.

The fresh air flow can now also be used to cool parts the oven door can be used, especially the door handle and / or the door interior to the temperatures diminish the door. For this, the fresh air flow is through appropriate training of the fresh air duct with these Brought into contact. The fresh air flow can also also for cooling one generally provided on the front Control panel and the controls arranged there of the oven.

The blower is preferably in a blower chamber for Leading the flow arranged. The blower chamber wall has at least one arranged in the suction area of the blower and with the vapor outlet opening in the muffle wall vapor intake opening connected via a vapor channel and at least one in the blow-out area of the blower arranged and connected to the discharge duct discharge opening on. The fresh air duct opens into the vapor duct, so that the fresh air is mixed with the vapor in front of the fan becomes. The fume channel is in particular through a the thermal muffle insulation located on the furnace muffle wall guided.

The wall of the vapor channel and at least part of the Wall of the fresh air duct can make installation easier coherent, especially from a common one Sheet metal part, be formed.

The vapor intake opening in the wall of the blower chamber preferably has a larger flow cross section than the vapor outlet opening in the muffle wall, and the Vapor channel then decreases in its flow cross section the vapor outlet opening towards the vapor suction opening, preferably essentially continuous, too (according to Art a diffuser). You can use a blower with a larger effective suction cross-section and thus a larger one Use power even without increasing its speed. This can remove the suction vacuum for the vapors the cooking space without changing the vapor outlet opening or shortening the vapor channel can be increased.

In an advantageous development, the wall of the Blower chamber additionally at least one cooling air intake opening on through which the blower chamber with the environment the furnace muffle in flow communication within an furnace housing stands. The fan then not only sucks vapors from the cooking space and fresh air, but also from the Oven muffle warms air in the oven housing, and thereby serves also as a cooling fan.

The blower is preferably a radial blower with a Axis of rotation and with at least one in one essentially parallel to the axis of rotation of the suction direction axial suction area and at least one essentially radial radial to the axis of rotation Blow-out area.

The radial fan can have two on opposite sides have suction areas lying on a parting plane (double-flow Execution). The at least one vapor intake opening the blower chamber is then in one of the suction areas and the cooling air intake opening of the blower chamber in the other of the two suction areas of the radial fan. The vapor intake opening of the blower chamber can in particular essentially symmetrical to the axis of rotation of the radial fan be arranged.

The radial fan can be a drum rotor. Preferably as a radial fan is a paddle wheel that can be rotated around the axis of rotation provided that preferably the vapor intake opening towered outwards in all directions from the axis of rotation. In this version, the paddle wheel (radial fan) Vapor guide vanes in the suction area assigned to the vapor intake opening exhibit. This enables an accurate Adjustment of the intake volume flow from vapors and Fresh air by choosing the number, the shape and the Vapor guide vane size. The impeller of the radial fan but can also on the vapor extraction opening facing Gas / air side only due to surface friction convey on the base plate.

The impeller of the radial fan preferably also has in the parting plane a partition plate and on that of the cooling air intake assigned suction area with the partition plate connected and, preferably substantially perpendicular cooling air guide vanes directed towards the separating plate through which the cooling air volume flow can be set can, especially in relation to the volume flow of the Fresh air / vapor mixture.

The vapor outlet opening is generally in the muffle ceiling arranged to additionally lift the thermal forces to use.

The blower chamber with the blower is in a preferred one Embodiment arranged above the muffle ceiling of the oven muffle, preferably above the vapor outlet opening. The vapor channel then runs essentially vertically upwards (against gravity). The blower chamber Of course, the muffle can also be in particular on its rear wall.

FIG 1

einen oberen Bereich eines Garofens in einem seitlichen Schnitt,

FIG 2

einen inneren oberen Bereich eines Garofens in einer Ansicht von seitlich oben

FIG 3

ein Lüfterrad für einen Garofen in einer Ansicht und

FIG 4

einen oberen Bereich eines Garofens gemäß FIG 1 mit einer durch die Frischluft gekühlten Tür in einem seitlichen Schnitt,.

To further explain the invention, reference is made to the drawings, in which exemplary embodiments according to the invention are each shown schematically. Show it:

FIG. 1

an upper area of a cooking oven in a lateral section,

FIG 2

an inner upper region of a cooking oven in a side view from above

FIG 3

a fan wheel for a cooking oven in one view and

FIG 4

an upper area of a cooking oven according to FIG 1 with a door cooled by the fresh air in a lateral section.

Corresponding parts are shown in FIGS. 1 to 4 provided the same reference numerals.

1 shows a cooking oven in a lateral section with an oven muffle 10 with one of a muffle wall (only muffle cover 17 and muffle rear wall 14 shown) Surrounded muffle interior (cooking space) 15, one at a front side 12 loading opening 16 in the muffle wall, through the food into the muffle interior 15 can be introduced, and a housing 83.

Above the muffle top 17 of the furnace muffle 10 is a blower chamber 3 arranged with a radial fan 2. The radial fan 2 preferably has one along an axis of rotation A. extended (elongated) shaft 22 and one on it Shank 22 attached, preferably symmetrical to the axis of rotation A trained base plate (carrier plate, partition plate) 21 on. The base plate 21 is in a directly on the Shaft 22 adjoining inner region dome-shaped (funnel-shaped) indented and in the outside area formed essentially flat. In the flat annular region of the base plate 21 are a plurality of cooling air guide vanes 20 provided on the base plate 21st attached or molded from this and essentially perpendicularly from the base plate 21 to one Cooling air intake opening 30 in the housing wall 31 of the blower chamber 3 stand out. The cooling air intake opening 30 is on the housing cover 33 facing away from the furnace muffle 10 Housing wall 31 of the blower chamber 3 is provided and can especially at the foot of one formed with the housing wall Suction funnel 32 may be arranged. In one of the oven muffle 10 facing housing base 34 of the housing wall 31 at least one vapor suction opening 36 is formed. This Vapor suction opening 36 is via a vapor channel 4 with a Vapor outlet opening 18 in the muffle top 17 of the Furnace muffle 10 connected. Preferably, the cooling air intake opening 30, the vapor intake opening 36 and the vapor outlet opening 18 each essentially to the center Axis of rotation A and preferably also rotationally symmetrical to the axis of rotation A. The radial fan 2 instructs its base plate 21 to the vapor intake opening 36 further Fan impeller blades, which are called vapor guide blades 25 are designated.

Except for the cooling air intake port 30 and the vapor intake port 36, the wall 31 of the blower chamber 3 has another one Opening that is not axial to the axis of rotation A, but perpendicular to it in the radial direction to the front of the oven is directed towards and referred to as blow-out opening 37 is. Otherwise, the wall 31 of the blower chamber 3 in particular the side wall 35 with respect to the circumferential direction the axis of rotation A around the radial fan 2, closed. Via a shaft 22 of the radial fan 2 connected holding device 60 is an electric drive motor 6 for rotating the radial fan 2 around its Axis of rotation A attached.

Between the housing base 34 of the blower chamber 3 and the Muffle cover 17 is a muffle insulation shown only partially 84 provided through which the vapor channel 4 is guided, the muffle insulation 84 on the channel wall 40 of the vapor channel 4 is present. The vapor channel 4 has one of the vapor outlet opening 18 in the muffle ceiling 17 increasing to the vapor intake opening 36 in the housing base 34 Cross-section, is therefore funnel-shaped or in the form of a Diffuser formed. The channel wall 40 and the housing base 34 can in particular with a common sheet metal part be formed so that the funnel-shaped vapor channel 4th Is part of the housing of the blower chamber 3. Furthermore is within of the vapor channel 4 an upward from the vapor outlet opening 18 extending vapors 41 formed, around which a channel-shaped condensate collecting area 42 is formed is. This has the advantage of being in the colder areas of the duct wall 40 condensing vapor condensate can collect in the condensate collection area 42 and not in the muffle interior 15 and on the inside Food can drip.

A fresh air duct runs from the front 12 of the oven 8 into the vapor duct 4. The fresh air duct 8 opens into an air passage area 55 on the front side 12 and with its other end facing one of the front 12 Side of the vapor channel 4 and runs essentially horizontally and parallel to the muffle ceiling 17. After The fresh air duct 8 is at the top through an air baffle 7 and bounded at the bottom by an air baffle 80 and sealed gastight.

To operate the radial fan 2, the drive motor 6 switched on, and the radial fan 2 starts around the Axis of rotation A with a predetermined by the drive motor 6 Direction of rotation and speed. By the rotation is designated by the cooling air guide vanes 20 with K2 Cooling air axially, i.e. essentially parallel to the axis of rotation A, sucked in and radial, i.e. perpendicular to the axis of rotation A to the outside, blown out. Since the blower chamber 3 only on the Blow-out opening 37 is open radially to the outside and the rest is completed by the side wall 35, the Cooled air K2 drawn in completely through the exhaust opening 37 discharged from the blower chamber 3. By the rotation of the radial fan 2 are also with the help of the Underside of the base plate 21 provided vapors 25 vapors marked W (air from the muffle interior, enriched with cooking and fat vapors in the cooking mode is) from the muffle interior 15 and designated K1 Fresh air from the outside 11 outside the Oven housing 83 sucked axially. The sucked in steam W flows successively through the vapor outlet opening 18, the vapor channel 4 and the vapor intake opening 36, the announced one Fresh air K1 successively through the fresh air duct 8 and the vapor intake opening 36. Also the mixture of vapor W and fresh air K1 is radial from the radial fan 2 directed outwards and completely through the blow-out opening 37 blown out of the blower chamber 3.

At the blow-out opening 37 of the blower chamber 3 there is a discharge channel (Exhaust duct) 5 connected, via which both the cooling air K2 as well as the vapors W (with the fresh air K1) as a gas mixture K1 + K2 + W up to the air passage area 55 is performed on the front 12 of the oven and there is led out into the outside space 11. On the front 12 of the oven is one above the air passage area 55 Control panel 50 with one or more control elements 51 and arranged behind the control panel 50 and with the Controls 51 connected controls 52, in particular may contain electronic components arranged.

On the one hand, the fresh air K1 has the function of the vapor W to dilute and thus contaminate the front 12 of the oven or in the air flow in from the air outlet opening 55 escaping airflow located objects to reduce, and on the other hand also a cooling function for the front area of the oven around the fresh air duct 8 and also the area around the diversion channel 5, since with the cool fresh air K1 also the mixture K1 + K2 + W in its Temperature is reduced. The ratio R1 = VK1 / VW des Volume flow VK1 of fresh air K1 to volume flow VW des Wrasens W is determined by the dimensions of the fresh air duct 8 and the vapor channel 4 with the associated inlet openings 55 or 18 determined and can be varied within a wide range become.

The ratio R1 of the volume flows of fresh air K1 and Wrasen W is preferably in a range between 1 and 5 (1 ≤ R1 ≤ 5).

In absolute terms, the volume flows VK1 and VW are selected as follows: The volume flow of the vapor W is generally between 2 m ³ / h and 10 m ³ / h and the volume flow VK1 of the fresh air K1 is between 2 m ³ / h and 50 m ³ / h .

The cooling air K2 can in the illustrated embodiment from the entire interior of the furnace muffle 10 Housing 83 are sucked, especially from the upper Area behind the control panel 50 in which the controls 52 are arranged to cool them as well one behind the muffle rear wall 14 and in front of the rear wall of the Housing 83 located flow channel 74 from below. Thereby the surroundings of the furnace muffle 10 are also cooled. The Area from which the cooling air K2 is sucked in, however also through flow directors or additional flow channels limited or specifically selected if one only wants to cool a part of the oven, for example for energy saving reasons. This section can in particular be a front area of the oven, in particular a door to close the loading opening 16 and preferably also the area of the control panel 50 with the temperature-sensitive electronic components in the controls 52.

In an embodiment not shown, however, can also the cooling air intake opening 30 in the blower chamber 3 is eliminated. The blower 2 is then no longer used to cool the other areas of the oven, but only the area around the fresh air duct 8 and also the discharge duct 5.

2 shows a side perspective view of a Oven from above, in which the blower chamber 3 by one Housing wall 31 is surrounded by the of the discharge opening 37 side facing substantially cylindrical is designed and towards the blow-out opening 37, for example linear, expanding. There are also in FIG Intake funnel 32 with the cooling air intake opening 30, the fastening device 60 on the radial fan 2 for the not shown drive motor and the cooling air guide vanes 20 and the base plate 21 of the radial fan located below to see. The diversion channel, which is actually hidden in FIG. 2 5 is through a baffle 58 in two partial flow channels divided by a share of each Mixture K1 + K2 + W from fresh air K1, cooling air K2 and vapors W each a blow-out opening (air passage area) 56th or 57 supplied on or under the control panel 50 and is blown out into the outer space 11 there. The diversion channel 5 also widens towards the blow-out openings 56 and 57 in width, so it is in the form of a diffuser. Below one the bottom of the diversion channel 5 forming air guide wall 7, a fresh air duct 8 is indicated, whose width varies from one to the width of the Control panel 50 extending air inlet opening 59 to Vapor channel 4 reduced. The air inlet opening 59 of the Fresh air duct 8 for transporting fresh air K1 to Radial fan 2 is below the two blow-out openings 56 and 57 arranged. The location and number of air intake openings 59 for the fresh air duct 8 can be varied. In particular, one or more air inlet openings 59 also laterally offset to the blow-out openings, e.g. 56 and 57, of the discharge channel 5, for example in the middle below the deflector 58. This will Air sucked in the middle of the front 12 of the oven and blown out on both sides. this makes possible For example, the targeted cooling of only one in the Middle door handle of a not shown Oven door. The fresh air duct 8 is then each in its Shape adapted accordingly to the air inlet openings 59.

In a departure from the illustrated embodiments, the housing wall 31 of the blower chamber 3 can preferably also be formed spirally in a manner known per se, for example from DE 42 11 755 A1 . The housing wall 31 of the blower chamber 3 and the walls of the channels 4, 5 and 8 are preferably formed with sheets, in particular steel sheets.

3 shows the radial fan in a more detailed view 2. There are the cooling air guide vanes 20 and opposite side of the base plate 21, the vapor guide vanes 25 recognizable. The cooling air guide vanes 20 and the vapor guide vanes 25 are parallel to the projection Axis of rotation A congruent one above the other and each in the same direction with respect to the radial direction to Axis of rotation A and the shaft 22 curved, in particular all convex or all concave. As special A backward curvature of the cooling air guide vanes has been found to be advantageous 20 and the vapor guide vane 25 proved in the case of an imaginary radial line from the axis of rotation A to the outside through a cooling air guide vane 20 or a vapor guide vane 25 extends all radially outer areas of the corresponding cooling air guide vane 20 or vapor guide vane 25 in the direction of rotation are moved forward.

The cooling air guide vanes 20 and the vapor guide vanes 25 can also be offset from one another in the circumferential direction, so not be congruent with each other. Can also a different number or shape of cooling air guide vanes 20 and vapor guide vanes 25 on the base plate 21 and / or the cooling air guide vanes 20 and / or the vapor guide vanes 25 also in mutually different ones Distances from each other (asymmetrical Arrangement), then on a corresponding The resulting imbalance must be compensated for. Finally, it can also be used to increase the suction effect one, in particular annular, cover the Cooling air guide vanes 20 may be provided upwards, so that the spaces between the cooling air guide vanes 20 down from the base plate 21 and up are completed by the cover.

The radial fan 2 can in particular consist of a coherent Be formed body, for example a sheet metal body, in which the cooling air guide vanes 20 and the vapor guide vanes 25 on a base plate 21 made of sheet metal a connection technology are applied, or by punching and bending up sheet metal material are formed. Furthermore, the radial fan 2 can also be made of a temperature-resistant Plastic consist, for example, by Injection molded body.

In all of the embodiments, structural measures which are matched to the selected rotational speed of the radial fan 2 now preferably achieve that the volume flow, the intake cooling air K2 is at least six times greater than the volume flow of the vapor W and the fresh air K1. It has been shown that with such a setting of the ratio R2 = VK2 / VW + VK1) of cooling air volume flow VK2 to the sum VK1 + VW from fresh air volume flow VK1 and vapor volume flow VW, even with a not too great suction effect for the vapors W from the muffle interior 15 Adequate cooling of the oven is achieved. The ratio R2 is set in particular in a range between approximately 2 and 25 and preferably between approximately 5 and approximately 18. A volume flow of the cooling air K2 of over 100 m ³ / h, in particular between 120 m ³ / h and 200 m ³ / h, preferably at about 150 m ³ / h, has proven to be expedient for cooling a built-in oven . In contrast, values of between 2 m ³ / h and 10 m ³ / h, in particular around 6 m ³ / h, are expedient for the volume flow of the vapor. Thus, the radial blower 2 simultaneously aspirates the smallest possible amount of vapor from the muffle interior 15 and a comparatively large amount of cooling air from the interior of the housing outside the furnace muffle 10.

• Anzahl, Größe und Gestalt der Kühlluftleitschaufeln 20 des Radialgebläses 2
• Anordnung und Abmessungen der Kühlluftansaugöffnung 30, insbesondere deren Strömungsquerschnitt
• Abstand der Kühlluftleitschaufeln 20 von der Kühlluftansaugöffnung 30.

The most important parameters for setting the cooling air volume flow VK2 are:

• Number, size and shape of the cooling air guide vanes 20 of the radial fan 2
• Arrangement and dimensions of the cooling air intake opening 30, in particular its flow cross section
• Distance of the cooling air guide vanes 20 from the cooling air intake opening 30.

The cooling air intake opening 30 is preferably centric arranged to the axis of rotation A, is in the simplest embodiment circular disk-shaped and has one smaller diameter than the radial diameter of the Radial blower 2. Regarding the shape of the cooling air guide vanes 20 has a backward curved shape the associated lower noise level proven. However, there are other forms of the cooling air guide vanes 20 possible. The height is particularly important the cooling air guide vanes 20, i.e. their dimensions parallel to the axis of rotation A, which is denoted by H in FIG. This height H of the cooling air guide vanes 20 is generally between about 4 mm and about 30 mm, especially between about 10 mm and about 20 mm and preferably between about 15 mm and about 20 mm, for example about 17.5 mm.

The distance between the radial fan 2 and the cooling air intake opening 30 is generally set to a value between about 4 mm and 10 mm and in particular between 5 mm and about 8 mm set depending on the operating speed of the radial fan 2. At an operating speed of 1860 RPM (revolutions per minute) has a gap distance proven of about 7 mm. With an additional ring-shaped Covering the cooling air guide vanes 20 can be the gap distance can be reduced to approx. 5.5 mm, especially with a also reduced speed of 1600 rpm to the to achieve the same cooling air volume flow VK2.

• Anzahl, Art und Formgebung der Wrasenleitschaufeln 25
• Anordnung und Abmessungen der Wrasenansaugöffnung 36, des Wrasenkanals 40 und der Wrasenaustrittsöffnung 18, sowie des Frischluftkanals 8 und der Frischlufteinlaßöffnungen insbesondere deren jeweilige Strömungsquerschnitte
• Abstand zwischen den Wrasenleitschaufeln 25 oder, bei fehlenden Wrasenleitschaufeln 25, der Grundplatte 21 von der Wrasenansaugöffnung 36 und der Wrasenansaugöffnung 36 sowie dem Gehäuseboden 34 der Gebläsekammer 3 (Spaltabstand).

The extracted vapor volume per unit of time (vapor volume flow VW) and the fresh air intake per unit of time VK1 are determined by the following factors:

• Number, type and shape of the vapor guide vanes 25
• Arrangement and dimensions of the vapor intake opening 36, the vapor channel 40 and the vapor outlet opening 18, as well as the fresh air channel 8 and the fresh air inlet openings, in particular their respective flow cross sections
• Distance between the vapor guide blades 25 or, in the absence of vapor guide blades 25, the base plate 21 from the vapor suction opening 36 and the vapor suction opening 36 and the housing base 34 of the blower chamber 3 (gap distance).

The vapor guide vanes 25 can in particular like that Cooling air guide vanes 20 can be curved, but can also have a different shape. An important parameter is the height of the vapor guide vanes 25, which is denoted by h in FIG is. This height h of the vapor guide vane 25 becomes generally chosen between about 1 mm and about 3 mm, in particular about 2 mm, but can also be chosen smaller and in particular only be 0 mm, i.e. that no vapor guide vane 25 are provided and the for suctioning the Wrasen's W required vacuum due to surface friction the base plate 21 of the radial fan 2 is reached. Preferably, the vapor intake opening 36 becomes substantially arranged centrally to the axis of rotation A in order to achieve a uniform To allow suction through the radial fan 2.

The gap distance is speed-dependent and is generally between about 1 mm and about 4 mm, especially between about 1.5 mm and about 3.5 mm. At a speed of 1600 rpm (without ring cover 1860 rpm) Proven gap distance of 3 mm. The vapor guide vanes 25 allow a greater tolerance in the choice of the gap distance, without backing up under the radial fan 2 into the muffle interior 15, a tilting of the ventilation system (Reversal of the flow direction). Thereby the system is less sensitive to manufacturing tolerances.

The arrangement of the radial fan 2 directly above the vapor outlet opening 18 and the resultant direct vapor extraction, unlike the injection principle, can adjust the amount of vapors exactly to the targets become.

In a modification, not shown, cooling air K2 and mixture of vapors W and fresh air K1 also on one be rejected elsewhere, for example via a associated hob. In particular, the outlet opening 37 and the subsequent diversion channel 5 also to the rear be directed towards the rear wall of the housing 83 and the mixture K1 + K2 + W from cooling air K2, fresh air K1 and vapors W also upwards at the back, for example in an extractor hood or the like. The deflector 58 could also be designed such that a subset of the Stroms K1 + K2 + W is fed to the door handle for cooling.

Instead of a fan wheel (fan wheel) with axially aligned In all embodiments, blades can be used as radial fans 2 also be provided with a drum fan radial guide vanes. Furthermore, instead of only one cooling air intake opening 30, vapor intake opening 36 or blow-out opening 37 also each corresponding Openings may be provided, for example in the form of a Hole pattern.

4 shows a development of the embodiment according to FIG 1, in which the fresh air K1 in addition to cooling a Door 9 to close the loading opening 16 of the Furnace muffle 10 is used. The door 9 has an upper Area a door handle 91 for handling the door 9 and between a front and a back, which is generally each include a viewing window, a door interior 90 on. In a lower area of the door 9 are Air inlet openings 93, not shown, and in the area of the door handle 91 a further air inlet opening 95 is provided. Furthermore, an air outlet opening 94 is directly opposite the air passage opening 55 of the fresh air duct 8 intended. As a result, both fresh air from the blower 2 K1 passed around the door handle 91 and through the air inlet opening 95 and the air outlet opening 94 in the fresh air duct 8 sucked as well as from below through the air inlet openings 93 Fresh air K1 through door interior 90 and likewise through the air outlet opening 94 into the fresh air duct 8 of the oven. The fresh air K1 therefore cools both the door handle 91 and the door interior 90 and thus also the door front. The fresh air duct 8 is in this Design on the door 9 extended towards the front, see above that a multiple flow paths (sub-channels) comprehensive Fresh air duct is created. The fresh air duct in the door 9 can be varied in a variety of ways. The Exhaust air K1 + K2 + W emerging from the discharge duct 5 becomes led out into the outer frame 11 above the door 9.

Reference list

2nd

Radial fan

3rd

Blower chamber

4th

Vapor canal

5

Discharge channel

6

engine

7

Partition plate

8th

Fresh air duct

9

door

10th

Oven muffle

11

Outside space

12th

Front

13

back

14

Muffle back wall

15

Muffle interior

16

Loading opening

17th

Muffle blanket

18th

Vapor outlet opening

20th

Cooling air guide vane

21

Base plate

22

shaft

25th

Vapor guide vane

26

Suction area

27

Suction area

28

Blow-out area

30th

Cooling air inlet opening

31

Wall

32

Suction funnel

33

Housing cover

34

Case back

35

Housing side wall

36

Vapor intake opening

37

Discharge opening

40

Channel wall

41

Vapor connection

42

Condensate collection area

50

Control panel

51

Control element

52

Control

55 to 57

Air passage area

58

Deflector

59

Air passage area

60

shaft

74

Space

80

Channel wall

83

casing

84

Muffle insulation

90

Door interior

91

Door handle

93

Air intake openings

94

Air outlet openings

95

Air inlet opening

K1

Fresh air

K2

Cooling air

W

Vapors

A

Axis of rotation

Claims (17)

Cooking oven, in particular built-in oven, comprising a) an oven muffle (10) with a muffle wall (14, 17) which surrounds a cooking space (15) and, preferably in the muffle top (17), has at least one vapor outlet opening (18), and b) a fan (2) arranged outside the muffle wall with at least one suction area (26), which is in flow connection with the vapor outlet opening of the muffle wall, and with at least one blow-out area (28), c) at least one fresh air duct (8) opening at one end into an outer space (11) and at the other end opening towards the suction area of the fan, d) at least one discharge channel (5) opening at one end into the blow-out area of the fan and at the other end opening into the outside space for discharging the mixture of the vapor (W) drawn in by the fan during its operation through the vapor outlet opening from the cooking chamber on the one hand and the fresh air (K1) drawn in from the outside through the fresh air duct on the other hand. Cooking oven according to claim 1 with a front side (12) the muffle wall has a loading opening (16) for Introducing food to be cooked in the oven and on one of the oven doors (9) for closing the charging opening is arranged, the fresh air duct opens into the outside at the front. Cooking oven according to claim 2, wherein the fresh air duct a) one with at least part of the door interior (90) of the oven door and one or more air inlet openings (93) in the oven door for the inlet of fresh air from the outside into the door interior and the first sub-channel b) comprises a second subchannel which is in flow communication with the first subchannel via one or more air outlet openings (94) in the oven door for the outlet of the fresh air from the interior of the door. Cooking oven according to claim 2 or claim 3, wherein a Part of the fresh air duct through a door handle (91) Oven door or in close proximity to the door handle. Cooking oven according to one of the preceding claims, which the diversion channel at the front into the outside space flows. Cooking oven according to one of the preceding claims, which the discharge duct runs above the fresh air duct. Cooking oven according to one of the preceding claims, that of the fresh air duct and the discharge duct at least predominantly above the oven muffle, preferably in essentially horizontal. Cooking oven according to one of the preceding claims, bie which the fresh air duct and the discharge duct through a common, preferably plate-shaped, Air guide (7) are separated from each other. Cooking oven according to one of the preceding claims, that the fresh air duct and the discharge duct in one common air passage area (55) or in separate and staggered air passage areas (59 or 56, 57) lead to the outside. Cooking oven according to one of the preceding claims, which the blower in one, preferably above the Muffle ceiling of the open muffle arranged, blower chamber (3) is arranged, the wall (31) of which is at least one arranged in the suction area of the blower and with the Vapor outlet opening in the muffle wall over one Vapor channel (4) connected vapor intake opening (36) and at least one arranged in the blow-out area of the blower and discharge opening connected to the discharge duct (37), and in which the fresh air duct in the vapor channel opens. Cooking oven according to claim 10, wherein the wall of the vapor channel and at least part of the wall of the Fresh air duct connected, in particular from one common sheet metal part, are formed. Cooking oven according to claim 10 or claim 11, wherein the Wall of the blower chamber additionally at least one Has cooling air intake opening (30) through which the blower chamber with the surroundings of the oven muffle inside of a furnace housing is in flow connection. Cooking oven according to one of the preceding claims, the blower is a radial blower (2) with an axis of rotation (A) and with at least one in one essentially suction direction parallel to the axis of rotation lying axial suction area (26, 27) and at least one essentially in the circumferential direction Radial blow-out area (28) is. Cooking oven according to claim 12 and claim 13, wherein the Radial blower two on opposite sides of one Separation plane lying suction areas and the at least a vapor intake opening of the blower chamber in one of the suction areas and the cooling air suction opening the blower chamber in the other of the two suction areas of the radial fan. Cooking oven according to one of claims 10 to 12 and one of claims 13 and 14, wherein the radial fan Paddle wheel rotatable about the axis of rotation, which preferably the vapor intake opening from the axis of rotation towering outwards in all directions. Cooking oven according to claim 15, wherein the radial fan in the vapor guide vanes assigned to the vapor intake opening (25) and a separating plate in the parting plane (21) and at that assigned to the cooling air intake opening Suction area connected to the partition plate and, preferably substantially perpendicular to the partition plate Directed, cooling air guide vanes (20). Method for removing vapors from a cooking space of a cooking oven, in particular a built-in oven, enclosed by a muffle wall, in which a blower arranged outside the muffle wall a) both vapors are sucked in from the cooking space through at least one vapors outlet opening in the muffle wall and fresh air from an outside space of the cooking furnace through at least one fresh air duct and b) the vapors mixed with the fresh air are blown out again into the outside space through an outlet duct.

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