EP1867929A2 - Steam cooking oven - Google Patents

Abstract

The oven (1) has a steam generator generating steam, and a cooking cavity (2) for receiving food to be heated by steam and comprising air inlet and outlet units. A vent (21) is placed in a front part of the cavity and proximity to a door of the oven. The vent aspires the steam and re-ejects the steam outside the cavity, where the distance between the door and the vent is lower than or equal to 6 centimeter. The cavity is ventilated for evacuating the steam by introducing the air via a ventilator (11) of an oven ventilalting system (18).

Description

The present invention relates to a steam cooking oven and more particularly to a device for discharging water vapor contained in a cooking cavity.

In a steam cooking oven, having a cooking chamber, the latter is generally brought to saturation in water vapor at atmospheric pressure by sending water on a heating element in the chamber. The cooking of food is then in this furnace chamber saturated with water vapor.

Some ovens do not have a system to evacuate the steam at the end of cooking. As a result, when the door of the baking oven is opened, a large quantity of steam suddenly comes out of the furnace chamber and is released into the room in which it is placed. This causes inconvenience to the user and can even be dangerous, which can cause burns. In addition, any damage can be caused to the surroundings by the release of steam, such as on walls and ceilings.

On the other hand, there are known steam cooking ovens equipped with a ventilation device for evacuating steam.

This ventilation device makes it possible to evacuate the steam during a cooking cycle in order to avoid the overpressure in the cavity and to partially evacuate the steam at the end of the cooking cycle in order to avoid having a puff of steam when opening the oven door.

These cooking ovens comprise a large outlet opening closed by a valve during cooking, and a plurality of holes in said valve to allow the evacuation of surplus steam enclosed in the cooking chamber and prevent a rise in pressure. of said cooking chamber.

Said large steam outlet opening and the plurality of holes in the valve for extracting the steam open into a furnace ventilation duct, downstream of the fan.

At the end of the firing cycle, a phase of partial evacuation of the steam by said large outlet opening of the cavity is implemented by progressively opening said valve.

Said phase of partial evacuation of the steam is achieved by a Venturi effect since said large outlet opening is disposed downstream of a fan, the blowing zone of said fan being in the ventilation duct of the furnace.

However, these baking ovens have the disadvantage of not evacuating most of the steam enclosed in the cavity of the oven although the cavity comprises a large steam evacuation opening and a large valve. The Venturi effect created by the fan of the oven ventilation system is not efficient enough to remove steam from the cooking chamber. In addition, the poor sealing associated with the steam evacuation device constituted by the valve, the ventilation duct and the cavity generates heat losses inside said cavity, hence an increase in the steaming times. food.

The present invention aims to solve the aforementioned drawbacks and to provide a steam oven equipped with a ventilation device to allow the continuous evacuation of steam during cooking food with steam and complete evacuation of the steam at the end of the cooking cycle.

For this purpose, the present invention is directed to a steam cooking oven comprising a cavity adapted to receive food to be heated by steam, a device for generating steam, and a ventilation system of said oven, said cavity comprising means air intake means and air outlet means, said air outlet means comprising at least one steam evacuation opening, said ventilation system comprising an opening and closing flap of said less an opening for evacuation of the steam.

• o une partie de la vapeur enfermée dans la cavité lors de la cuisson des aliments est évacuée, ledit au moins un évent aspirant la vapeur et rejetant ladite vapeur en dehors de ladite cavité ; et
• o la cavité est ventilée pour évacuer la vapeur enfermée dans ladite cavité en introduisant de l'air à l'aide d'un ventilateur appartenant au système de ventilation dudit four par ledit au moins un évent.

According to the invention, the steam-cooking oven comprises at least one vent placed in the front part of the cavity and close to a door of said oven, in which:

• o part of the steam enclosed in the cavity during cooking food is discharged, said at least one vent sucking steam and rejecting said vapor outside said cavity; and
• o the cavity is vented to evacuate the steam enclosed in said cavity by introducing air with a fan belonging to the ventilation system of said oven by said at least one vent.

Thus, said at least one vent has a dual function.

Said at least one vent allows on the one hand to evacuate the excess steam enclosed in the cavity to cook the food vapor at atmospheric pressure during a steaming cycle. Said at least one vent makes it possible to suck the steam and to reject it outside the cavity.

Said at least one vent has a mode of operation by Venturi effect during the cooking phase of food to evacuate the steam enclosed in the cavity.

The Venturi effect is implemented by a ventilation duct arranged in flow relation with said at least one vent. A blower blows air into the vent duct and creates a vacuum at at least one opening of the at least one vent and draws the vapor enclosed in the cavity to extract steam outside the cavity.

The evacuation of a portion of the steam enclosed in the cavity during cooking of food by steam is carried out continuously.

Said at least one vent also makes it possible, during the ventilation phase of the cavity by introducing air through the at least one vent, particularly at the end of the steam cooking cycle, to invert the ventilation device of the cavity. the cavity and allow the stirring of the saturated cavity with steam by an introduction of air through the at least one vent. The introduction of air is effected by said at least one vent in flow relationship between a ventilation duct and the steam cooking cavity.

Said at least one vent makes it possible to introduce air and push the steam inside the cavity to evacuate said vapor through said at least one discharge opening.

The evacuation of a portion of the steam and the ventilation of the cavity by at least one air introducing vent is implemented by a difference in air pressure between the inside and the outside of said cavity .

Said at least one vent has a mode of operation by introduction of air during the ventilation phase of the cavity to evacuate the vapor enclosed in said cavity before the opening of the door of said oven, the introduction of air by said at least one vent for generating an air flow of said at least one vent to said at least one steam discharge opening within said cavity.

The introduction of air into the cavity by said at least one vent is effected by a fan blowing air into a ventilation duct. Said ventilation duct draws air through at least one inlet opening, and said air is mixed with steam from the cavity coming from said at least one discharge opening of said cavity. A vacuum is created at at least one opening of said at least one vent opening into the cavity, this depression generating a suction of the air blown by the fan towards said cavity.

Said at least one vent makes it possible to create a circulation inside the cavity of said at least one vent towards said at least one steam evacuation opening of said cavity.

Ventilation of the cavity to evacuate the steam enclosed in said cavity by introducing air using a fan belonging to the ventilation system of said oven is performed before opening a door of said oven.

Said at least one vent is formed in an upper wall of the cavity.

Said at least one vent of said furnace makes it possible to ventilate a dead zone of the cavity near the door during the cooking phase of the foodstuffs, the air circulation in said cavity cooling the vapor close to the door, where an attenuation of the condensation on an inner wall of said door.

The distance between the door of said oven and said at least one vent is less than or equal to 6 cm and preferably of the order of 4 cm.

Thus, the efficiency of the steam cooking oven is increased for steam cooking cycles.

The evacuation of the vapor through the at least one vent allows the vapor-laden air to be removed near the door. The air in this area of the cavity near the door is cooled by the heat exchange caused by the air outside the cavity.

In this way, the steaming oven door is non-condensing and the heat distribution within the cavity is made more uniform, hence a cooking time of the food by the reduced steam. The temperature difference between the area of the cavity near the door and the remainder of said cavity is now negligible.

In addition, the steam generator produces less steam for equivalent or even improved cooking results by reducing energy and water consumption.

The distance between the door and the at least one vent is minimized to optimize the performance of the steam cooking oven.

Moreover, during the ventilation phase of the cavity, the positioning of the at least one vent in the front part of the cavity and close to the oven door makes it possible to completely ventilate the cavity by minimizing the dead zones inside the cavity. said cavity, from which a complete evacuation of the steam enclosed in said cavity.

Said at least one vent makes it possible to introduce air and circulate said air along the internal walls of the cavity so as to avoid condensation on the walls, and in particular on the inner wall of the door by positioning said less a vent in the front part of the cavity.

Said at least one steam evacuation opening of the cavity is disposed downstream of the fan of the furnace ventilation system to improve the steam evacuation performance of said cavity during the ventilation phase of said cavity. Said at least one steam evacuation opening of the cavity is located outside the ventilation duct comprising said at least one vent.

Preferably, said at least one steam evacuation opening of the cavity is in flow relation with a suction zone of the fan. The steam of the cavity is conducted by a second conduit between said at least one cavity vapor discharge opening and a fan suction zone.

Said at least one opening for evacuating the steam from the cavity is closed off by a valve during the ventilation phase of said cavity.

Said at least one vent connects the cavity of said oven to a ventilation channel located above the upper wall of said cavity.

In practice, the at least one vent comprises four air and vapor passages centered on the upper wall of the cavity and extending over the width of said wall. upper of said cavity.

Said at least one vent is made of plastic.

Thus, said at least one vent can be integrated in the ventilation duct also plastic located along a wall of the cooking cavity.

• une accélération du flux d'air introduit par ledit au moins un évent dans la cavité lors de la phase de ventilation de ladite cavité, et
• une dépression accrue au niveau du conduit de ventilation lors de la phase d'évacuation de la vapeur de la cavité par ledit au moins un évent se déroulant au cours d'un cycle de cuisson à la vapeur. L'effet Venturi réalisé au niveau de la sortie dudit au moins un évent dans ledit conduit de ventilation est amélioré et permet d'extraire la vapeur de la cavité en quantité suffisante.

Furthermore, the plastic material of said at least one vent makes it possible to simply and at low cost said at least one nozzle-shaped vent. The size of the at least one vent widens away from the cavity. Said at least one vent is of substantially conical shape to allow:

• an acceleration of the flow of air introduced by said at least one vent into the cavity during the ventilation phase of said cavity, and
• an increased depression in the ventilation duct during the steam evacuation phase of the cavity by said at least one vent taking place during a steam cooking cycle. The Venturi effect achieved at the outlet of the at least one vent in said ventilation duct is improved and allows the steam to be extracted from the cavity in sufficient quantity.

The at least one vent and the at least one steam outlet are disposed in the upper wall of the cavity.

Other features and advantages of the invention will become apparent in the description below.

• la figure 1 représente une vue de face schématique et partielle d'un four de cuisson à la vapeur conforme à l'invention ;
• la figure 2 représente une vue de dessus schématique et partielle d'un four de cuisson à la vapeur conforme à l'invention ;
• la figure 3 représente une vue schématique et en coupe d'un four de cuisson à la vapeur lors de la phase d'évacuation de vapeur d'un cycle de cuisson à la vapeur conforme à l'invention ;
• la figure 4 représente une vue schématique et en coupe d'un four de cuisson à la vapeur lors de la phase de ventilation de la cavité conforme à l'invention ;
• la figure 5 représente une vue de dessus schématique et partielle d'une cavité d'un four de cuisson à la vapeur conforme à l'invention ; et
• la figure 6 représente une vue de dessus schématique d'un système de ventilation d'un four de cuisson à la vapeur conforme à l'invention.

In the accompanying drawings, given as non-limiting examples:

• Figure 1 shows a schematic and partial front view of a steam cooking oven according to the invention;
• FIG. 2 represents a diagrammatic and partial plan view of a steam cooking oven according to the invention;
• FIG. 3 is a diagrammatic sectional view of a steam cooking oven during the steam evacuation phase of a steam cooking cycle according to the invention;
• Figure 4 shows a schematic sectional view of a steam cooking oven during the ventilation phase of the cavity according to the invention;
• Figure 5 shows a schematic and partial top view of a cavity of a steam cooking oven according to the invention; and
• Figure 6 shows a schematic top view of a ventilation system of a steam oven according to the invention.

With reference to FIGS. 1 and 2, a steam cooking oven 1 according to the present invention essentially comprises a cooking chamber 2 and a steam generator. steam 3.

The steam generator 3 essentially comprises a steam generation unit 5 and a water supply device 6.

The steam generating block 5 is made from materials providing good thermal conductivity, for example aluminum. Said steam generating unit 5 comprises, in a single piece of aluminum, an upper part forming a water evaporation bowl 7 and a lower part forming a heating block 8.

Alternatively, the water evaporation pan 7 and the heating block 8 can be made in the form of two separate parts assembled to each other.

The heating block 8 is equipped with a heating resistor, a temperature sensor and a temperature limiter. These elements can be mounted at different locations in the heating block 8.

Preferably, the heating resistor is crimped on the heating block 8 so as to obtain a thermal contact of good quality.

The water supply device 6 is of the gravity feed type. This water supply device 6 comprises a water tank (not shown), a water supply pipette 9 and a solenoid valve (not shown).

The water supply pipette 9 includes a first end which is located at the center of the water evaporation pan 7. A second end of the water supply pipette 9 is connected to the reservoir through the solenoid valve and a connecting pipe, to form a water supply circuit.

The cooking chamber 2 is equipped with a temperature probe 10 and a thermal activator (not shown). Preferably, the cooking chamber 2 is also equipped with a heating sheet (not shown) and a ventilation / cooling turbine 11.

The temperature sensor 10 provides control means (not shown) with a temperature measurement inside the cooking chamber 2.

In a conventional manner, the thermal activator is supplied by the control means of the oven 1 and operates in opening / closing a steam evacuation valve 20.

Preferably, a steam dish (not shown) is placed on a rack-shaped support. This steam dish is raised relative to a bottom wall 12 of the cooking chamber 2. The height of the support is dimensioned so that the steam plate 4 is above the water supply pipette 9.

In another embodiment of the invention, the support may be steps formed in the side walls 13 of the cooking chamber 2 or attached to said side walls 13.

An embodiment of the steam evacuation device enclosed in a cooking cavity of a steam cooking oven according to the invention will now be described, with reference to FIGS. 2 to 6.

The steaming oven 1 comprises a cavity 2 adapted to receive food to be heated by steam, a steam generating device 3, and a ventilation system 18 of said oven 1.

Said cavity 2 is substantially of parallelepipedal shape comprising an upper wall 16, a lower wall 12, three side walls.

The steaming oven 1 comprises a door 22 adapted to seal the cavity 2 in a sealed manner and to allow the introduction and removal of food in said cavity 2.

Said cavity 2 comprises air inlet means and air outlet means, said air outlet means comprising at least one discharge opening 19 of the steam.

Said ventilation system 18 comprises a valve 20 for opening and closing said at least one evacuation opening 19 of the steam.

The steam evacuation device enclosed in a cooking cavity 2 of a steam cooking oven 1 comprises a ventilation duct 5 in which is placed a fan 11 of centrifugal type or also called radial axial. The ventilation duct 5 consists of an upper guide 14 of plastic material and a lower guide 15 of sheet metal. The ventilation duct 5 is located above the upper wall 16 of the cooking cavity 2.

The fan 11 of the ventilation duct 5 has a suction zone in the upper part of the oven between the cavity 2 and the housing (not shown).

The blowing zone of the fan 11 disposed inside the ventilation duct 5 opens on the front face 36 of the steaming oven 1. In practice, the steaming oven 1 comprises at least one air outlet opening 25 located on the front face 36 of the oven 1 so as to evacuate the mixture of air and steam from the cavity 2 to the Oven exterior 1.

Said at least one air outlet opening 25 is disposed between the control panel 26 and the door 22 of the oven 1 and preferably extends over a large width of the upper wall 16.

Moreover, the ventilation duct 5 makes it possible to create a ventilation of the oven so as to cool the electrical, mechanical and electronic components of the steam cooking oven 1.

The fan 11 consists of a motor 31 and a propeller 17. Said fan 11 is operated from the start of a steaming cycle of the oven 1. Said fan 11 blows continuously in the ventilation duct 5.

The ventilation duct 5 comprises an air inlet opening 29 formed on its upper wall and in line with the propeller 17 placed inside said ventilation duct 5.

The ventilation duct 5 comprises a support 30 for the motor 31 of the fan 11. Said motor 31 is located in the suction zone of the fan 11 and at the right of the air inlet opening 29 so as to be cooled by the flow of air entering the ventilation duct 5.

Said cavity 2 of the oven 1 is generally made of stainless steel.

• o d'évacuer une partie de la vapeur enfermée dans la cavité 2 lors de la cuisson des aliments par de la vapeur ; et
• o de ventiler la cavité 2 pour évacuer la vapeur enfermée dans ladite cavité 2 en introduisant de l'air à l'aide d'un ventilateur 11 appartenant au système de ventilation 18 dudit four 1 par ledit au moins un évent 21.

The steaming oven 1 comprises at least one vent 21 allowing:

• o evacuate a portion of the steam locked in the cavity 2 when cooking food with steam; and
• o to ventilate the cavity 2 to evacuate the vapor enclosed in said cavity 2 by introducing air using a fan 11 belonging to the ventilation system 18 of said furnace 1 by said at least one vent 21.

Said at least one vent 21 is placed in the front part of the cavity 2 and close to the furnace door 22.

Said at least one vent 21 allows the continuous evacuation of excess steam in order to avoid putting the cavity 2 under an overpressure during a steam cooking cycle.

Said at least one vent 21 is located closer to the door 22 of the oven 1 to allow the continuous evacuation of the steam to remove the heat-cooled vapor with said door 22 having a temperature below the temperature of the steam generated by the steam generator 3.

The evacuation of a portion of the steam enclosed in the cavity 2 during cooking of food by steam is carried out continuously.

A second auxiliary duct 23 is formed in part with the main ventilation duct 5 in order to connect the cavity 2 to a blowing zone of the fan 11. The second auxiliary duct 23 connects said at least one discharge opening 19 of the steam the cavity 2 at the central zone of the propeller 17 of the fan 11, and particularly at the depression zone of said propeller 17.

Said at least one evacuation opening 19 of the steam of the cavity 2 is preferably located downstream of the fan 11.

Said at least one evacuation opening 19 of the steam of the cavity 2 is located outside the main ventilation duct 5 so as not to create any pressure losses inside it.

A valve 20 for opening and closing said at least one opening evacuation 19 of the steam of the cavity 2 is controlled by a jack with thermal activation 24. The valve 20 closes said at least one discharge opening 19 of the steam during a steam cycle .

The valve 20 may comprise a seal (not shown) or be made of silicone material to reduce the cost of the steam evacuation function of the cavity 2.

The evacuation of a portion of the steam and the ventilation of the cavity 2 by at least one vent 21 is implemented by a pressure difference of the air between the inside and the outside of said cavity 2.

The ventilation of the cavity 2 to evacuate the vapor enclosed in said cavity 2 by introducing air using a fan 11 belonging to the ventilation system 18 of said oven 1 is performed before opening a door 22 said oven 1.

The second auxiliary duct 23 allows the evacuation of the steam at the end of a cooking cycle by creating a depression at the level of said at least one discharge opening 19 of the steam of the cavity 2. The evacuation of the steam from the cavity 2 at the end of the cooking cycle by the second auxiliary duct 23 makes it possible to avoid the puff of steam when opening the door 22.

This suction principle is more efficient than a Venturi effect system where the at least one steam evacuation opening 19 is placed upstream of the fan 11.

The diameter of said at least one discharge opening 19 of the steam is of small size, and substantially of the order of 6 cm in diameter.

At the end of a steaming cycle, the heat-activated jack 24 is supplied with electrical energy to open the valve 20 of the at least one steam discharge opening 19 of the cavity 2. The fan 11 creates a depression in the second auxiliary conduit 23 during opening of the valve 20 and allows the suction of the vapor contained in the cavity 2 by said at least one discharge opening 19. The steam extracted from the cavity 2 is mixed with air at the propeller 17 of the fan 11 and the mixture is discharged to the outside through the ventilation duct 5 and then at least one air outlet opening 25 at the front face 36 of the oven 1.

Said at least one air outlet opening 25 may consist of an air gap placed between the control panel 26 and the door 22 of the oven.

Part of the mixture of air and steam is also introduced into the cavity 2 by said at least one vent 21 so as to create a ventilation inside said cavity 2.

Said at least one vent 21 is formed in an upper wall 16 of the cavity 2.

Said at least one vent 21 has a mode of operation by introduction of air during the ventilation phase of the cavity 2 to evacuate the vapor enclosed in said cavity 2 before the opening of the door 22 of said oven 1.

The introduction of air by said at least one vent 21 makes it possible to generate an air flow of said at least one vent 21 towards said at least one steam evacuation opening 19 inside said cavity 2.

Said at least one vent 21 connects the cavity 2 of said oven 1 to a ventilation channel 5 located above the upper wall 16 of said cavity 2.

Said at least one vent 21 comprises four air and vapor passages centered on the upper wall 16 of the cavity 2 and extending over the width of said upper wall 16 of said cavity 2.

Said at least one vent 21 is made of plastic.

Said at least one vent 21 and said at least one steam outlet opening 19 are disposed in the upper wall 16 of the cavity 2.

Said at least one vent 21 is placed on the front part of the cavity 2 and close to the door 22 to allow complete ventilation of said cavity 2, whence a complete evacuation of the vapor contained in said cavity 2.

During the ventilation phase of the cavity 2 at the end of the cooking cycle, the steam evacuation device uses said at least one vent 21 to introduce air into the cavity 2.

Thus, a stirring of air and steam is carried out from the at least one steam evacuation opening 19 of the cavity in the second auxiliary duct 23 opening into the suction zone of the fan 11, then the air mixture. and steam is blown into the main duct 5 of the fan 11 opening into at least one outlet opening 25 to extract the mixture to the outside, and the mixture of air and steam also introducing into said at least one vent 21 to cross the cavity 2. The air flow introduced into the cavity 2 by said at least one vent 21 follows the walls of said cavity 2 to prevent the formation of condensation thereon.

During a cooking cycle, said at least one vent 21 makes it possible to remove a portion of the steam from the cavity 2.

Said at least one vent 21 has a mode of operation by Venturi effect during the cooking phase of food to evacuate the vapor enclosed in the cavity 2.

Said at least one vent 21 of said furnace 1 makes it possible to ventilate a dead zone of the cavity 2 close to the door 22 during the cooking phase of the foodstuffs, the circulation of air in said cavity 2 attenuating the condensation on an inner wall of said door 22.

The distance between the door 22 of said oven 1 and said at least one vent 21 is less than or equal to 6 cm, and preferably of the order of 4 cm.

The positioning of the at least one vent 21 near the door 22 increases the efficiency of the oven and reduce the cooking time of food steam.

The steam evacuation device according to the invention makes it possible to guarantee equivalent or even improved cooking performance, in particular for the rise in temperature and the temperature regulation of the cooking chamber 2.

The steam evacuation device according to the invention makes it possible to evacuate the excess steam continuously during cooking and completely at the end of the cooking cycle without cooling the food or degrading the cooking qualities.

The withdrawal of the food placed in the cavity 2 is done safely at the opening of the door 22 since all of the steam has been removed during the ventilation phase of said cavity 2 by introduction of air by said at least one vent 21.

The fan 11 can continue to blow air into the main ventilation duct 5 when the door 22 is opened. Part of the air blown by the fan 11 is introduced into the at least one ventilation port 21. to create a curtain of air to prevent a residual amount of steam can go back to the user.

The user can open the door 22 of the cavity 2 safely and without risk of burns by the steam.

The operation of the steaming oven 1 is as follows.

The food is disposed inside the cavity 2 and the door 22 is closed. The cavity 2 is brought to saturation of steam under atmospheric pressure by sending water to a heating element. During the cooking phase of the food, the valve 20 is closed. The fan 11 blows air sucked between the housing and the cavity 2 and all of the air is expelled to the outside of the furnace 1. A Venturi effect is created at the level of the at least one vent 21 so as to remove the excess steam of the cavity 2. The cooled steam near the door 22 is withdrawn by said at least one vent 21 so as to equalize the temperature inside the cavity 2.A quantity of vapor is sucked by the air flow through the ventilation duct 5. During the cooking phase, successive water supplies maintain the saturation of water vapor in the cavity 2. At the end of cooking, the enclosure is therefore saturated with steam. water at 100 ° C. To avoid any risk of burns by the steam when opening the door 22, the steam evacuation device described above is implemented for about three minutes before the end of cooking. The valve 20 is opened by the actuation of the heat-activated jack 24 thus allowing the suction of the vapor by said at least one discharge opening 19. The vapor circulates in the second auxiliary conduit 23 to the suction zone of the fan 17 of the fan 11. The air sucked by the air inlet opening 29 of the ventilation duct 5 is mixed with the steam leaving the second auxiliary duct 23. The mixture of air and vapor is expelled through the ventilation duct 5 to said at least one outlet opening 25 and a portion of the mixture is introduced into the cavity 2 by said at least one vent 21. The mixture of air and steam allows the steam to circulate inside the cavity 2 and along the walls of the latter to exit through said at least one steam evacuation opening 19. Said at least one discharge opening 19 and said At least one vent 21 is directed towards the top of the cavity 2. Mixing the air with the steam makes it possible to cool the water vapor, thus preventing any risk of burns for the user.

After an opening time of the valve 20 predetermined by the Applicant as a function of the flow rates of entry and exit and the volume of the cavity 2, the door 22 of the oven 1 can be opened safely.

With this device and this cooking process, the cavity 2 of the steam cooking oven 1 can be emptied of the water vapor in a relatively short time, substantially less than three minutes, for the greatest safety and comfort of the user.

This steam evacuation device prevents the discharge of hot steam outside the oven 1 not to degrade ceilings or surrounding walls.

Steam is introduced into the fan 11 without risk of deterioration since said vapor is introduced into the vacuum zone of the propeller 17 and is immediately rejected in the ventilation duct 5.

The steaming oven 1 comprises a cavity 2 adapted to receive food to be heated by steam and enclosed in a housing (not shown), a steam generating device 3, and a ventilation system 18 of said oven 1 .

Said cavity 2 comprises air inlet means and air outlet means. Said air outlet means comprising at least one evacuation opening 19 of the steam.

Said ventilation system 18 comprises a first ventilation duct 5. Said first ventilation duct 5 comprises an air inlet opening 29 in an upper wall of said first ventilation duct 5, and an air outlet opening 25 in front face 36 of the oven 1

Said ventilation system 18 also comprises a radial axial fan 11 placed inside the first ventilation duct 5, the radial axial fan 11 comprises a propeller 17 placed in line with said inlet opening 25 of the first ventilation duct 5.

Said at least one evacuation opening 19 of the steam of the cavity 2 opens into a first end 37 of a second ventilation duct 23 and into outside the first ventilation duct 5.

Said second ventilation duct 23 comprises a second end 38 opening into an axial suction zone of the fan 17 of the fan 11 and into an inlet opening 29 of the first ventilation duct 5.

The suction of steam from the second ventilation duct 23 and the intake of fresh air into the inlet opening 29 of the first ventilation duct 5 is carried out in a suction zone situated above a plane transverse 33 of the propeller 17 of the fan 11, said transverse plane 33 of said propeller 17 being perpendicular to an axis of rotation 34 of said propeller 17.

Thus, the suction of the steam by said at least one steam discharge opening 19 towards the inlet opening 29 of the first ventilation duct 5 is effected by suction through the second ventilation duct 23.

Said at least one evacuation opening 19 of the steam is upstream of the fan 11 to improve the efficiency of the steam evacuation device.

The steam is completely sucked by the propeller 17 of the fan 11 since the second end 38 of the second ventilation duct 23 is directly placed in the suction zone of said propeller 17 of said fan 11.

In this way, the corrosion problems of the electrical and short-circuit components are eliminated. The steam is sucked into the first ventilation duct 5 and discharged outside the oven 1. The steam does not diffuse outside the first and second ventilation ducts 5 and 23.

Preferably, the second end 38 of the second ventilation duct 23 opens into the inlet opening 29 of the first ventilation duct 5 and close to a decompression zone of the air 32 driven by the fan 11 inside. the first ventilation duct 5.

The provision of the second end 38 of the second ventilation duct 23 in relation to the decompression zone 32 of the first ventilation duct 5 makes it possible to best diffuse the vapor throughout said first ventilation duct 5. This arrangement also makes it possible to limit the contact of the steam with the walls of the first ventilation duct 5 and cause condensation. The vapor is kept in suspension in the air without coming into contact with the walls and out of the oven through the outlet opening 25 of the first ventilation duct 5 on the front face 36 of said oven 1.

In addition, the position of the second ventilation duct 23 having a first end 37 for conducting the steam of the cavity 2 outside the first ventilation duct 5 and a second end 38 opening into the inlet opening 29 of the first duct ventilation 5 makes it possible to reduce the noise of the ventilation system 18 of the oven 1. The ventilation system 18 of the oven 1 is constructed in such a way as not to generate any noise in the first ventilation duct 5 by removing any element creating a pressure drop inside thereof.

Said at least one steam evacuation opening 19 of the cavity 2 is located in an area not covered by the first ventilation duct 5. Said at least one steam evacuation opening 19 of the cavity is placed close to the first ventilation duct 5 so as to extract the steam and introduce it into the inlet opening 29 of the first ventilation duct 5 and into the suction zone of the fan 11. The fan 11 requires ventilation blades only on a single surface of the transverse plane 33 to the propeller 17. Thus, the development of the fan 11 is simplified by adjusting that the fan blades of the propeller 17 disposed above the transverse plane 33 to the propeller 17 of the fan 11.

According to a preferred feature of the invention, the steam channeled by the second ventilation duct 23 is mixed with fresh air in a central zone of the fan 17 of the propeller 11, said fresh air coming from the space between the cavity 2 and the housing.

The fresh air comes from the space between the cavity 2 and the housing to avoid excessive heat exchange.

Fresh air from the outside of the oven 1 is too cool and causes condensation at the entrance of the first ventilation duct 5, this condensation being sprayed to the outside of the oven 1 and is unpleasant for the user . For this reason, the fresh air supply is only taken between the cavity 2 and the housing and not directly outside the oven 1.

The mixture of the steam coming from the second ventilation duct 23 and from the fresh air is carried out in an area above the transverse plane 33 to the propeller 17 of the fan 11.

The mixture of air and steam is effected on one side of the propeller 17 of the fan 11, and particularly above the transverse plane 33 of the propeller 17 of the fan 11.

Steam and air are drawn axially by the propeller 17 of the fan 11 placed in the first ventilation duct 5.

In this way, the air inlet flow in the inlet opening 29 of the first ventilation duct 5 is without disturbances, in particular by an air inlet coming from a radial air flow. The amount of air and steam is optimized to improve the efficiency of the steam evacuation device contained in the cavity 2.

The single suction of fresh air in the first ventilation duct 5 is carried out axially to the propeller 17 of the fan 11.

The first ventilation duct 5 comprises a single inlet opening 29 placed above the fan 11.

The suction created in the second ventilation duct 23 is maximum and ensures complete evacuation of the steam from the cavity 2.

The passage section of the steam in the second ventilation duct 23 is substantially constant so as not to cause disturbances. Thus, the vapor flow is laminar inside the second ventilation duct 23.

The second ventilation duct 23 comprises a separating element 39 making it possible to connect the upper part of the second ventilation duct 23 to the lower part of the second ventilation duct 23. Said separation element 39 is in the form substantially of a drop of water and extending to the second end 38 of the second ventilation duct 23.

Said separation element 39 makes it possible to guarantee a flow of laminar air inside the second ventilation duct 23 and inside two ducts formed in the latter.

The ratio between the steam passage section in the second air duct 23 and the inlet opening 29 of the first section 5 Outlet conduit is between ^1/6 and 1/3.

In the embodiment of the invention, the passage section of the steam in the second ventilation duct 23 is of the order of 15 cm ² . The surface of the inlet opening 29 of the first ventilation duct 5 is of the order of 78 cm ² .

Said at least one evacuation 19 of steam from the cavity 2 is placed near the first ventilation duct 5.

In this way, the length of the second ventilation duct 23 is of minimum length and the pressure drops are reduced to a minimum. The second ventilation duct 23 can thus be partly achieved by the first ventilation duct 5 in order to minimize the costs of obtaining the ventilation system 18 of the steam cooking oven 1. The lower part of the second ventilation duct 23 is formed by the outer shape of the first ventilation duct 5.

The second ventilation duct 23 comprises a valve 20 allowing the opening and closing of the at least one steam evacuation opening 19 of the cavity 2.

Said valve 20 makes it possible to close and open the said at least one evacuation opening 19 of the steam as a function of the phases of the firing cycle. The valve 20 makes it possible to control the evacuation of the vapor contained in the cavity 2.

Said at least one steam evacuation opening 19 of the cavity 2 is placed in the rear third of said cavity 2.

The position of the at least one steam evacuation opening 19 in the rear third of the cavity 2 makes it possible to ensure complete evacuation of the steam without create a thermal shock on food. The food is sensitive to the change of temperature during the evacuation of the steam contained in the cavity 2.

Said at least one steam evacuation opening 19 is placed on the upper wall 16 of the cavity 2. In another embodiment of the invention, said at least one steam evacuation opening 19 can be placed on the rear wall 40 of the cavity 2.

In addition, the position in the last third of the cavity 2 of said at least one steam discharge opening 19 of the cavity 2 allows with at least one vent 21 to ventilate said cavity 2 by limiting the dead zones. Said at least one vent 21 is preferably disposed near the oven door 22.

• une lame d'air située au niveau de ladite au moins une ouverture de sortie 25 en face frontale 36 du four 1,
• un guide d'air inférieur 15 peut être réalisé en matière plastique et être produit avec un guide d'air supérieur 14 lui-même en matière plastique,
• un ou plusieurs supports 27 d'une carte électronique de commande du four de cuisson 1 à la vapeur,
• un ou plusieurs moyens de fixation 28 d'un faisceau électrique.

The main ventilation duct 5 made of plastic material makes it possible to integrate functions such as:

• an air space located at said at least one outlet opening 25 at the front face 36 of the oven 1,
• a lower air guide 15 may be made of plastic material and be produced with an upper air guide 14 itself made of plastic,
• one or more supports 27 of an electronic control board of the steaming oven 1,
• one or more fastening means 28 of an electric harness.

The steam evacuation device consisting of the main ventilation duct 5, the second auxiliary duct 23, the fan 11, of said at least one vent 21 may also comprise a plastic cavity top 2 to reduce the costs of the function. evacuation of steam. In addition, this steam evacuation device makes it possible to remove a sealing means to be placed between the cavity 2 and the second auxiliary duct 23.

This steam evacuation device may also make it possible to remove a heating mat placed around the cavity 2 in the case where a portion of the cavity 2 is made of plastic so as to reduce the amount of condensate caused by the contact of the with the said cavity 2. The stainless steel currently used to manufacture the cavity 2 causes a large amount of condensate when the steam is in contact with said cavity 2.

Of course, many modifications can be made to the embodiments described above without departing from the scope of the invention.

Claims (12)

Steam oven comprising a cavity (2) adapted to receive food to be heated by steam, a steam generating device (3), and a ventilation system (18) of said oven (1), said cavity (2) comprising air inlet means and air outlet means, said air outlet means comprising at least one steam discharge opening (19), said ventilation system (18) comprising a valve (20) for opening and closing said at least one steam outlet (19), characterized in that it comprises at least one vent (21) located in the front part of the cavity ( 2) and near a door (22) of said oven (1) by which: o part of the steam enclosed in the cavity (2) during cooking of the food is evacuated, said at least one vent (21) sucking the steam and rejecting said vapor outside said cavity (2); and the cavity (2) is ventilated to evacuate the vapor enclosed in said cavity (2) by introducing air by means of a fan (11) belonging to the ventilation system (18) of said oven (1) by said at least one vent (21). Steam cooking oven according to claim 1, characterized in that said at least one vent (21) is formed in an upper wall (16) of the cavity (2). Steam cooking oven according to one of Claims 1 to 2, characterized in that the evacuation of part of the steam and the ventilation of the cavity (2) by at least one vent (21) introducing the air is implemented by a difference in air pressure between the inside and the outside of said cavity (2). Steam cooking oven according to one of Claims 1 to 3, characterized in that the evacuation of a part of the steam which is enclosed in the cavity (2) during the cooking of the food by steam is carried out continuously. Steam cooking oven according to one of Claims 1 to 4, characterized in that the ventilation of the cavity (2) for evacuating the vapor enclosed in said cavity (2) by introducing air using a fan (11) belonging to the ventilation system (18) of said oven (1) is produced before the opening of a door (22) of said oven (1). Steam cooking oven according to any one of claims 1 to 5, characterized in that said at least one vent (21) has an operating mode by Venturi effect when the cooking phase of the food to evacuate the steam enclosed in the cavity (2). Steam oven according to one of Claims 1 to 6, characterized in that said at least one vent (21) has a mode of operation by introducing air during the ventilation phase of the cavity (2) to evacuate the vapor enclosed in said cavity (2) before the opening of the door (22) of said oven (1), the introduction of air through said at least one vent (22) for generating an air flow of said at least one vent (21) to said at least one opening of evacuation (19) of the vapor inside said cavity (2). Steam cooking oven according to any one of claims 1 to 7, characterized in that said at least one vent (21) connects the cavity (2) of said oven (1) to a ventilation channel (5) located at above the upper wall (16) of said cavity (2). Steam cooking oven according to any one of claims 1 to 8, characterized in that said at least one vent (21) comprises four air and vapor passages centered on the upper wall (16) of the cavity ( 2) and extending across the width of said upper wall (16) of said cavity (2). Steam cooking oven according to any one of claims 1 to 9, characterized in that said at least one vent (21) is made of plastic. Steam cooking oven according to any one of claims 1 to 10, characterized in that said at least one vent (21) and said at least one discharge opening (19) of the steam are arranged in the upper wall (16) of the cavity (2). Steam cooking oven according to any one of claims 1 to 11, characterized in that the distance between the door (22) of said furnace (1) and said at least one vent (21) is less than or equal to 6cm, and preferably of the order of 4cm.

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