COOKING OVEN

Abstract

A Cooking oven (100) comprising a) at least one cooking cavity (102) and b) at least one steam generation system (40) for introducing steam into the cooking cavity (102) during a steam operating mode, in particular steam cooking mode or steam cleaning mode, c) wherein the steam generation system (40) comprises c1) at least one steam generator (42), c2) at least one fluid supply (44), the fluid preferably being water with impurities, in particular calcium, and optionally additives and c3) at least one valve (2), d) wherein the valve (2) is interconnected between the fluid supply (44) and the steam generator (42) in order to control the flow of fluid from the fluid supply (44) to the steam generator (42) during the steam operating mode, e) wherein the valve (2) comprises at least one inlet (12) for the fluid being in fluid connection with the fluid supply (44) f) wherein the valve is in fluid connection with the steam generator (42) by means of at least one connecting line (50), g) wherein the valve (2) is provided with at least one closing device (19) for closing and opening the inlet (12) of the valve at least partially during the steam operating mode in order to keep the fluid level within the valve at an operating level within an operating level range during the steam operating mode, h) the cooking oven further comprising one or more of the following features: h1) the valve (2) and the steam generator (42) and the connecting line (50) are arranged in such a way that the level of the fluid within the steam generator (42) and within the valve (2) is kept the same during the steam operating mode and/or wherein the valve (2) and the steam generator (42) and the connecting line (50) are arranged according to the principle of communicating vessels, h2) the operating level (N) or the operating level range during the steam operating mode is, in the direction of gravity, higher than or at the same level as the inlet (12) of the valve (2).

Claims

1. Cooking oven comprising: a cooking cavity; a steam generation system for introducing steam into the cooking cavity during a steam operating mode, in particular steam cooking mode or steam cleaning mode wherein the steam generation system comprises: a steam generator, a fluid supply that in use will supply, a fluid comprising water, and a valve; wherein the valve is interconnected between the fluid supply and the steam generator and is configured to control a flow of fluid from the fluid supply to the steam generator during the steam operating mode; wherein the valve comprises an inlet in fluid connection with the fluid supply; wherein the valve is in fluid connection with the steam generator via a connecting line; wherein the valve further comprises a closing device configured to close and open the inlet of the valve at least partially during the steam operating mode in order to keep a fluid level within the valve at an operating level within an operating level range during the steam operating mode; the cooking oven further comprising one or more of the following features: the valve and the steam generator and the connecting line are arranged in such a way that a level of the fluid within the steam generator and the level of the fluid within the valve are kept the same during the steam operating mode and/or wherein the valve and the steam generator and the connecting line are arranged according to a principle of communicating vessels, the operating level or the operating level range during the steam operating mode is, in a direction of gravity, higher than or at a same level as the inlet of the valve.

2. Cooking oven according to claim 1, wherein the valve comprises an outlet for the fluid and wherein the outlet and the steam generator are interconnected by the connecting line, and wherein the operating level or operating level range is, in the direction of gravity, higher than the outlet of the valve, and/or wherein the fluid supply, in the direction of gravity, is arranged higher than the valve and/or the steam generator.

3. Cooking oven according to claim 1, wherein the operating level or a maximum operating level of the operating level range is lower than a maximum filling level of the valve and/or wherein the operating level or a minimum operating level of the operating level range is higher than a minimum filling level of the valve and/or the valve is only partially filled at the operating level.

4. Cooking oven according to claim 1, wherein the closing device of the valve is operated by a force exerted on the closing device by the fluid and the closing device comprises a floater floating in the fluid within the valve, wherein the closing device further comprises a closing portion coupled to or arranged at the floater for closing and opening the inlet of the valve at least partially during the steam operating mode in order to keep the fluid level within the operating level range during the steam operating mode.

5. Cooking oven according to claim 1, wherein the operating level or the operating level range during the steam operating mode is, in the direction of gravity, higher than the closing device of the valve, and/or wherein the closing device is partially or completely continuously immersed into the fluid during the steam operating mode and/or wherein a closing portion of the closing device is continuously immersed into the fluid during the steam operating mode.

6. Cooking oven according to claim 1, wherein the closing device closes the inlet completely when a maximum operating level of the operating level range is reached, and/or wherein the closing device opens the inlet at least partially when an operating level within the operating level range having a predetermined distance from the maximum operating level is reached, and/or wherein the inlet is opened completely by the closing device when a low or minimum operating level within the operating level range is reached, and/or wherein the closing device comprises an elastic material and/or is inserted into the inlet when closing the inlet and/or wherein the closing device comprises an elastic sealing surface for sealing against a sealing surface of the inlet.

7. Cooking oven according to claim 1, wherein the steam generation system comprises a steam injector arranged at the cooking cavity for injection of steam generated by the steam generator into the cavity, wherein the steam injector is arranged higher, in the direction of than the valve and/or the steam generator, wherein the fluid supply is arranged higher, in the direction of gravity, than the steam injector, wherein the steam generation system further comprises a precipitator arranged between the steam generator and the steam injector, wherein the steam generation system further comprises a return line for fluid condensed in the precipitator, wherein the return line connects a precipitator fluid outlet with the connecting line and/or with the valve.

8. Cooking oven according to claim 1, wherein the steam generation system is at least partially arranged at a rear and outside of the cooking cavity, and/or wherein the valve and the steam generator are arranged at opposite sides of a blower drive arranged out-side of the cavity, and/or wherein the valve and the steam generator are in fluid communication with a drain valve.

9. Cooking oven according to claim 1, wherein the steam generator is of generally tubular shape and/or wherein the steam generator extends in a direction in-lined at an angle of between 25? and 90? to a horizontal direction, which is orthogonal to the direction of gravity, and/or wherein the return line and the steam generator and also a part of the connecting line and are arranged in V-shape or, alternatively, along straight lines including an acute angle between 0? and 30?.

10. Cooking oven according to claim 7, wherein the precipitator, the return line and at least a part of a housing of the valve are formed integrally or in a single piece, and/or wherein at least a part of the housing of the valve and at least a part of the connecting line are formed integrally or in a single piece, and/or wherein the precipitator, the return line and the housing of the valve and at least a part of the connecting line are formed integrally or in a single piece.

11. Cooking oven according to claim 2, wherein the valve comprises: a) a housing with an inner space for receiving the fluid, wherein the inlet and the outlet are arranged at or formed at or in the housing or a housing wall of the housing, b) the inlet being arranged at a side wall of the housing, c) wherein the operating level or the operating level range during the steam operating mode is, in the direction of gravity, higher than the inlet of the valve.

12. Cooking oven according to claim 4, a) wherein the floater is pivotably arranged inside a housing of the valve, wherein a pivoting position of the floater depends on a pivot momentum resulting from buoyancy acting on the floater when the floater is at least partially arranged inside said fluid within the valve housing, b) the floater being pivotably attached to a bottom wall and/or a side wall of the housing, wherein a pivoting axis of said floater is close to the bottom wall.

13. Cooking oven according to claim 12, the floater being pivotally attached to the bottom wall by a hinge comprising an axis mount; the axis mount being integrally formed at and/or extending from the bottom wall and/or the axis mount being integrally formed at and/or extending from a portion of the side wall contiguous with the bottom wall of the housing and/or the hinge comprises an axle attached to the floated or extending through the floater.

14. Cooking oven according to claim 4, wherein the floater comprises a hollow floater body having a bottom face and a side face, wherein a pivoting axis of the floater is located close to the bottom face and the side face of the floater body and/or intersects the floater body, and/or wherein an acute angle is enclosed between the bottom face and the side face of the floater body, wherein a pivoting angle around a pivoting axis and the acute angle are in an identical plane, and/or wherein the floater body is shaped as a prism, and/or wherein the closing portion is arranged or formed at and extends from the side face, from a protruding side face portion protruding from the side face or from an arm extending from or along the side.

15. Cooking oven according to claim 4, wherein a housing of the valve comprises a top wall, a side wall and a bottom wall, the side wall extending between the top wall and the bottom wall, wherein an air vent is located in the top wall of the housing, and/or wherein the floater comprises a floater body that is made from two moulded floater shells welded together, or from a lower floater part and a floater lid, or wherein the floater body is formed integrally by blow molding.

16. A cooking oven comprising a cooking cavity and a steam generating system configured to deliver steam to the cooking cavity during a steam operating mode; the steam generating system comprising a fluid supply, a steam generator, and a valve fluidly interconnected therebetween; the valve comprising a housing having an inlet configured to receive a supply of fluid from the fluid supply, and a valve outlet configured to deliver the fluid from said housing to the steam generator; the valve housing and an interior volume of the steam generator being in open fluid communication in order that in operation they will share a common fluid level as a result of a continuous fluid path therebetween; the valve further comprising a floater disposed within the housing thereof, said floater being movable between a closing position and an opening position as a result of its buoyancy based on the fluid level in the housing; wherein in the closing position a sealing surface of a closing portion of the floater is sealingly urged against a sealing surface of the inlet thereby closing off the inlet to fluid flow, and in the opening position the sealing surface of the closing portion is at least partially separated from the sealing surface of the inlet thereby opening the inlet to fluid flow; wherein the floater passively maintains the common fluid level within an operating level range during the steam operating mode, without a pump or application external energy beyond flow of the fluid through the valve housing, as a result the floater's buoyancy causing the floater to move: toward the opening position as the common fluid level recedes as the fluid is converted to steam in the steam generator, and into the closing position as a result of the common fluid level rising from inflow of the fluid through the housing inlet while the inlet is open.

17. The cooking oven according to claim 16, said fluid supply being located above said valve in order that the fluid is delivered from the fluid supply to the valve solely by gravity; said floater being pivotable between said closing and opening positions about a pivot axis defined by a hinge; both said inlet and said outlet being located below the operating level range of the fluid within the valve housing such that they are continuously immersed in the fluid in operation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The present invention will now be further described with reference to exemplary embodiments and the accompanying drawings.

[0067] FIG. 1 shows a first embodiment of an oven with a first embodiment of a steam generation system,

[0068] FIG. 2 shows a side view of an oven,

[0069] FIG. 3 shows a second embodiment of a steam generation system,

[0070] FIG. 4 shows a first embodiment of a valve in a closed state,

[0071] FIG. 5 shows the first embodiment of the valve in an open state,

[0072] FIG. 6 shows a cross section of the valve in the first embodiment,

[0073] FIG. 7 shows a second embodiment of the valve,

[0074] FIG. 8 shows a third embodiment of the valve,

[0075] FIG. 9 shows a fourth embodiment of the valve,

[0076] FIG. 10 shows a fifth embodiment of the valve,

[0077] FIG. 11 shows a sixth embodiment of the valve, and

[0078] FIG. 12 shows a seventh embodiment of the valve.

[0079] Corresponding parts and quantities are designated by the same reference signs in the FIGS. 1 to 12.

[0080] The cooking oven 100 according to FIGS. 1 and 2 comprises a cooking cavity 102 arranged in a casing 104 as visible in the side view in FIG. 2 and a steam generation system 40. The steam generation system 40 is provided for introducing steam into the oven cavity 102 by means or at a steam injector 64 in a steam operating mode, which might be for example a steam cooking mode or a steam cleaning mode.

[0081] The steam generation system 40 comprises a steam generator 42 arranged behind or on the rear side 108 of the cooking cavity 102 and a fluid supply 44. The fluid supply 44 is in particular a drawer or tank 45 accessible from a front side 106 of the oven 100 and is preferably arranged above of the cooking cavity 102. The fluid supply 44, in particular the tank 45, is in the embodiment provided with an optional overfill tube 70 for discharging fluid, in particular water, into the oven cavity 102 in case the user overfills the fluid supply 44, in particular the tank 45. The steam generation system 40 further comprises a valve 2, which is fluidly interconnected between the fluid supply 44 and the steam generator 42. An inlet line 46 is in this embodiment connecting the tank 45 to the valve 2, but the valve 2 may also be arranged directly in a lower region of the tank 45 for instance.

[0082] Steam generated in or by the steam generator 42 is guided into the cooking cavity 102 to a steam injection position 62. Injection of the steam into the cooking cavity 102 is preferentially provided by the steam injector 64. The steam injector 64 is typ-ically arranged above or? in the vicinity of a fan arranged on the back side of the oven. The fan is provided with a blower drive 110. The blower drive 110 can be fixed at a carrier plate 112 as shown or at a chassis or casing of the cooking oven 100. In the shown preferred embodiment, the valve 2 and the steam generator 42 are arranged at opposite sides of the blower drive 110.

[0083] The steam generator 42 and the valve 2 are in fluid communication with each other by means of a connecting line 50. In this embodiment, the connection line 50 is interconnected preferably between an outlet 14 of the valve 2 and an inlet of the steam generator 42.

[0084] The steam generator 42 and valve 2 are in further fluid communication with a drain system 56 comprising a drain valve 60 and an optional drain line 58. However, the drain system 56 is optional. This drain system 56 is in particular arranged below the valve 2 and the steam generator 42 to allow a flow into the drain system by gravity, if desired by a user.

[0085] The steam generator 42 can be a tubular steam generator as shown in FIG. 1, having a lower end 42a serving as an inlet and an upper end 42b serving as an outlet. The upper end 42b of the steam generator 42 may be, as shown, connected to a precipitator 52, allowing to separate steam from droplets or condensed fluid. The droplets or condensed fluid are/is returned to an inlet of the steam generator 42, in particular by a return line 54. The return line 54 could be connected directly to the steam generator 42 or with a line or tube connected to the inlet of the steam generator 42, as shown in FIG. 1. The return line 54 and the steam generator 42 are arranged in a V-shape. The precipitator 52 is arranged higher than the steam generator 42. The precipitator 52 is provided with a steam outlet 53 near a steam injection position, which is in fluid, in particular in steam communication, with the steam injector 64. The steam generator 42 is arranged in an inclined position, however, the inclination angle shown is not limiting and may be adapted to the space arrangement or requirements of the cooking oven 100. The steam generator 42 has a maximum fluid level and a typical operating level range.

[0086] The valve 2 and the steam generator 2 and the connecting line 50 are arranged in such a way that the level of the fluid within the steam generator 42 and within the valve 2 is kept the same or at the same height during the steam operating mode in particular by the steam generator 42 and the valve 2 and the connecting line 50 being arranged or form communicating vessels.

[0087] The valve 2 is arranged and provided to keep the filling level or operating level of the steam generator 42 in an operating level range. and that the level of the steam generator does not drop under a minimum operating level during operation. No pump or further valve are arranged between the steam generator 42 and the valve 2 or necessary.

[0088] A nominal operating level of the steam generator 42 and of the valve 2 are indicated by the dashed line N. This nominal operating level is the operating level or inside the operating level range for the level control of the valve 2 and the steam generator 42. The valve 2 is provided with a closing device 19 for opening and closing the inlet 12 of the valve 2 at least partially during the steam operating mode in order to keep the fluid level within the valve 2 at the operating level or within the operating level range. The inlet of the valve is arranged below this nominal operating level marked with the dashed line N.

[0089] The outlet 14 of the valve is arranged at the bottom of the valve 2. The valve 2 shown with a housing 4 may be equipped with a floater 20, which will be discussed below. The valve 2 may further have an air outlet 16 with is connected with air vent line 48 to the fluid supply 44. This air vent line 48 might be connected as shown to the fluid supply 44. The valve 2 and the steam generator 42 may be attached to the carrier plate 112.

[0090] FIG. 3 shows an alternative embodiment of a steam generation system, which could be a substitute for the system in FIG. 1. This embodiment shows a more compact design. The steam generator 42 of FIG. 3 is arranged vertically.

[0091] The valve 2 is provided with an integrated housing 4. The housing 4 is provided with an inlet 12 at a side wall of the housing. In the upper region of the housing there might be an air vent 16 as depicted. The housing 4 is directly connected to the steam generator 42 by means of the outlet 14 of the housing 4 and a further inlet 13 of the housing. The housing 4 is partly C-shaped. The closing device 19 with the floater 20 and a closing portion 22 are located near the inlet 12, in order to close the inlet 12 with the closing portion 22 to keep the fluid at operating level or operating level range. One end of a pivoting range of the floater 2 is given by the protrusions 9, against which the floater 2 may abut.

[0092] The housing 4 of the valve 2 is provided integrally with a precipitator 52 and a connecting line 50 and a return line 54. The housing 4 has a drain outlet for connecting a drain valve 60.

[0093] The precipitator 52 is provided at a position above the further inlet 13. The precipitator 52 is provided with a further outlet 15 of the housing 4, forming a precipitator outlet 53, for guiding the steam to a steam injection position 62 and thus to a steam injector 64. The precipitator is connected with a portion of the housing forming the return line 54. The return line 54 is further connected with a connection line 50, which is an integral part of the housing 4. This part forming the connection line 50 leads the fluid to the outlet of the housing 14 connected to the lower end 42a of the steam generator. Thus, to the contrary of the embodiment shown in FIG. 1, the connection line 50 is arranged in fluid direction before the outlet 14 and not between the outlet 14 and the steam generator 42. The connection line 50 is further in fluid communication with a drain valve 60. The floater of the embodiment can be designed according to any of the embodiments of the valve described below with the FIGS. 4 to 12.

[0094] The depicted partial C-shape of the housing is not limiting. In particular a further tank region could be included in particular including a lower part of the return line 42 and an upper part of the connecting line 50. The outlet 14 could be arranged facing downward for being connected by a connection element with the steam generator and optionally a drain system. Such a tank region and or the precipitator might be provided with baffle walls.

[0095] The housing 4 as depicted in FIG. 3 might be formed in particular from two shells connected with each other. Inlet and outlet might be each provided on one of the shells.

[0096] FIG. 4 to 12 show different embodiment of the valve being a pure mechanical floater valve. The valves 2 are provided with a housing 4 enclosing a floater 20. The housing 4 is provided with an inlet 12 arranged at a side wall 10 of the housing 4. The housing 4 is further provided with a bottom wall 8, wherein the outlet 14 is arranged in the bottom wall 8. The inlet 12 is arranged near a lower edge or near the bottom wall 8 of the housing 4.

[0097] In a top wall 6 of the housing 4, there is arranged an air vent 16.

[0098] The housing 4 is provided with a bracket 26 at an upper end for attaching the housing 4 of the valve 2 at a casing or a carrier plate 112 of an oven. However, this attachment bracket is exemplary and other known possibilities for fixing the valve housing are possible.

[0099] In the shown embodiments the housing 4 has a top part 17 and a bottom part 18, wherein the bottom part 18 comprises the bottom wall 8 and the top part 17 comprises the side wall 10 and the top wall 6 as well as the inlet 12. However, a housing made for example from two shells, comprising half the inlet and half the outlet is as well possible. Each of the inlet 12, the outlet 14 and the optional air vent 16 might be provided with sleeves 12a, 14a, 16a or flanges for attaching tubes.

[0100] Inside the housing 4, there is arranged a closing device 19 being provided with a floater 20 and a closing portion 22.

[0101] FIGS. 4 and 5 show a first embodiment of the floater in the closing position in FIG. 4 and in an opening position in FIG. 5. The closing portion 22 is attached directly to a side face 29a of a floater body 21. The floater 20 is attached with a hinge at the bottom wall 8. The hinge comprises an axis mount 28 and pivoting pins 27. The pivoting pins 27 extends from opposing sides 36a,b of the floater body 21. The pivoting pins 27 define the pivoting axis 24. The axis mount 28 extends from the bottom wall 8. The axis mount can also be constituted partially by a protrusion extending from the bottom wall and partially by a protrusion extending from the side wall as shown with FIG. 12. The floater body 21 has the shape of a trapezoidal prism with an angle ? which is located near the hinge and shown at the left corner in the figures. In the closing position of the closing device 19, in particular the closing portion 22, as shown in FIG. 4 the maximum fluid level M is above the inlet. The closing portion 22 is immersed into the fluid. In the open position the fluid level intersects the water inlet. The fluid flows continuously in the fluid. In the open position the fluid level may be also completely higher than the inlet instead of intersecting it. The pivoting angle ? is indicated in the drawing.

[0102] FIG. 6 shows a cross section of the embodiment of FIG. 4. The closing portion 22 is provided with a ring shaped outer sealing surface 22b and a protrusion 22a arranged in the middle. The protrusion 22a is inserted into the inlet, while sealing of the inlet is performed at the outer sealing surface 22b, being a smooth surface, against a sealing surface 12b of the inlet. The closing portion 22 is preferably made from an elastic material for example rubber.

[0103] FIG. 7 shows a floater body having a protruding side face portion 32. The closing portion 22 extends form the protruding side face portion 32. The pivoting pins 27 are located at opposing sides in the protruding side face portion 32.

[0104] FIG. 8 show an embodiment of the floater comprising an arm 34 extending along the side face 29b. The closing portion 22 extends from the arm 34. The arm 34 is connected to the floater body near or at the hinge. There may be present also other connecting members between the side wall of the floater and the arm 34 like stiffening brackets in order to maintain structural in-tegrity.

[0105] FIG. 9 shows an embodiment with a floater having in principle only right angles. In particular also the angle ? is a right angle. The floater body 21 has a lower floater part 23a and a lid 23b. This embodiment shows a recess in side face 37, which could be or is as well present in the other embodiments depicted through FIGS. 4 to 11.

[0106] FIG. 11 shows a floater body 21 having a trapezoidal prims shape. The angles ?, ?, ? and ? are marked in this figure. Those angles are all different from each other, or at least one different from the others. The angles ? and ? might be complementary angles, summing up to 180?. The angles ? and ? might be both right angles FIG. 10 shows a floater body having a recess 25 in the bottom face and the further side face. This recess 25 is one option to avoid any blocking of the outlet. Another possibility for avoiding a blocking of the outlet are protrusions 9 as marked in the FIGS. 4 and 5. Those protrusions 9 limit the pivoting movement of the floater 2.

[0107] FIG. 12 shows a further embodiment of the valve 2, wherein the floater 20 is attached to a hinge, having an first axis mount part 28a that is attached to the bottom wall 8 and a second axis mount part 28b that is attached to the side wall 10. An axle 35 extends through the axis mount parts and the floater 20 in particular an arm 34 of the floater 20. This axle 35 might be provided alternatively as pivoting pins 27 extending from the floater. The first axis mount part 28a might be formed such the axle 35 or pivoting pins 27 bear on a convex top surface of the first axis mount part 28a and they are fixed by the second axis mount part 28b. The closing portion 22 might be attached directly to the side wall of the floater or as shown in FIG. 8 on an arm 34.

LIST OF REFERENCE NUMERALS

[0108] 2 valve [0109] 4 housing [0110] 6 top wall [0111] 8 bottom wall [0112] 9 protrusion [0113] 10 side wall [0114] 12 inlet [0115] 12a sleeve [0116] 12b sealing surface [0117] 13 further inlet [0118] 14 outlet [0119] 14a sleeve [0120] 15 further outlet [0121] 16 air vent [0122] 16a sleeve [0123] 17 top part [0124] 18 bottom part [0125] 19 closing device [0126] 20 floater [0127] 21 floater body [0128] 21a,b floater shell [0129] 22 closing portion [0130] 22a protrusion of closing portion [0131] 22b sealing surface [0132] 23a lower floater part [0133] 23b floater lid [0134] 24 pivoting axis [0135] 25 recess [0136] 26 bracket [0137] 27 axis pin [0138] 28 axis mount [0139] 28a first axis mount part [0140] 28b second axis mount part [0141] 29a bottom face [0142] 29b side face [0143] 29c second side face [0144] 29d top face [0145] 30 recess [0146] 32 protruding side portion [0147] 34 arm [0148] 35 axle [0149] 36a,b opposing side faces [0150] 37 recess in side face [0151] 40 steam generation system [0152] 42 steam generator [0153] 42a steam generator inlet [0154] 42b steam generator outlet [0155] 44 fluid supply [0156] 45 tank [0157] 46 inlet line [0158] 48 air vent line [0159] 50 connecting line [0160] 52 precipitator [0161] 53 steam outlet [0162] 54 return line [0163] 56 drain system [0164] 58 drain line [0165] 60 drain valve [0166] 62 steam injection position [0167] 64 steam injector [0168] 70 line [0169] 100 cooking oven [0170] 102 cavity [0171] 104 casing [0172] 106 front side of oven [0173] 108 back side of oven [0174] 110 blow drive [0175] 112 carrier plate [0176] ? first angle [0177] ? second angle [0178] ? third angle [0179] ? fourth angle [0180] ? pivot angle