EP3702680A1

EP3702680A1 - Cooking oven with a cleaning system

Info

Publication number: EP3702680A1
Application number: EP19159495.1A
Authority: EP
Inventors: Antonio Asquini; Mauro BRISOTTO; Davide PELLICCIA
Original assignee: Electrolux Professional SpA
Current assignee: Electrolux Professional SpA
Priority date: 2019-02-26
Filing date: 2019-02-26
Publication date: 2020-09-02

Abstract

The present invention is related to cooking oven (1) for foodstuffs comprising: - a cooking chamber (2), wherein foodstuffs can be placed for being cooked, - a vapour outlet duct (9) configured for discharging vapour from the cooking chamber (2) to the external of the cooking oven (1), - a cleaning system (70) for cleaning the cooking oven (1), comprising a vapour outlet duct cleaning pipe (450) configured for taking a cleaning liquid within said vapour outlet duct (9). The vapour outlet duct (9) comprises an internal surface (90) having a circular, or substantially circular, or oval, or substantially oval, cross section. The vapour outlet duct cleaning pipe (450) is configured for emitting within the vapour outlet duct (9) a flow of cleaning liquid (451) generating a swirl of cleaning liquid (452) flowing on the internal surface (90).

Description

The present invention relates to a cooking oven with a cleaning system, and in particular to a "professional" oven, i.e. and oven used mainly in professional activities, like restaurants, canteens, hotels, etc.
The invention also relates to a method for cleaning such an oven.
Typically, professional ovens for foodstuffs comprise a housing, typically made of steel, containing a cooking chamber wherein foodstuffs can be placed for being cooked.
The cooking chamber is frequently provided with removable trays or racks, where food and/or pots or backing trays containing foodstuff can be placed.
The cooking chamber is typically parallelepipedal, and it is provided with a bottom wall wherein the grease dripping from foodstuff during the cooking is collected, and periodically drained via a cooking chamber outlet fluidly connected, typically via a valve, to a grease container external to the oven.
The oven is also provided with a heating device, e.g. an electric heater, or a gas heater, configured for heating the internal of the cooking chamber.
Typically, professional ovens are also provided with a ventilation system for circulating air within the cooking chamber during the cooking process, so as to make uniform the temperature within the internal of the cooking chamber.
Professional ovens are also typically provided with a vapour outlet duct, configured for discharging vapour from the cooking chamber during the cooking process; discharging the vapour is essential for keeping the pressure, the humidity, and the temperature within the cooking chamber within prefixed ranges specific for the kind of food to be cooked.
It is underlined that in the present application the word "vapour" has to be understood indiscriminately as pure steam, or as a mixture of steam and air and/or gasses.
The vapour outlet duct is also typically provided with a quenching system for dehumidifying and cooling down the vapour before discharging it into the external environment; typically, the quenching system comprises a nozzle provided within the vapour outlet duct and positioned in such a way to spray a jet of fresh water against the vapour passing through the vapour outlet duct, so as to cool down the vapour and to condensate the humidity contained therein.
Condensate is drained from the vapour outlet duct via a condensate draining conduit fluidly connected to an oven outlet configured for draining liquid outside the cooking oven.
The cooking chamber and the various components of the oven where liquids and fluids are collected and flow (pipes, reservoirs, etc.), need to be periodically cleaned (e.g. washed, degreased, descaled) in order to ensure hygiene and preserve the correct functionalities of all the components.
In particular, the vapour outlet duct needs to be frequently cleaned, since its inner surface is typically exposed to greasy cooking vapours and gets dirty during cooking. If not cleaned frequently, the available cross section for vapour flow can be narrowed, reducing the vapour emission speed, and consequently making difficult or impossible an accurate and fast humidity control of the cooking atmosphere within the cooking chamber, which is essential for most of the cooking processes.
Known solutions for cleaning the vapour outlet duct comprise a cleaning system provided with a pipe for taking a cleaning liquid (e.g. water, or a solution of water and a cleaning additive) within the duct, at which outlet there is a nozzle which protrudes within the duct until its central longitudinal axis; the nozzle sprays a jet of cleaning liquid directed against the internal surface of the duct, in a direction opposite to the travelling direction of the vapours.
The main problem of these know solutions is that, since the nozzle is positioned axially to the vapour outlet duct, there is the risk that the jet of cleaning liquid does not uniformly contact the internal surface of the vapour outlet duct, with the risk of not effectively cleaning the latter.
Furthermore, being positioned axially to the vapour outlet duct, the nozzle can obstruct the flow of vapour during the cooking process.
In addition, since the jet of cleaning liquid is sprayed by the nozzle from an axial region of the vapour outlet duct, and therefore it traverses the free cross section of the latter, there is the risk that, if an airflow is flowing in the duct during the spraying, this airflow could drag part of the jet of cleaning liquid out of the vapour outlet duct, and therefore out of the cooking oven, before it reaches the internal surface of the vapour outlet duct, with the risk of dirtying or polluting the external environment, and in any case reducing the cleaning action on the vapour outlet duct. In known solutions, typically, the fan of the cooking oven is operated during the cleaning of the cooking chamber in order to distribute the cleaning liquid on the internal surfaces of the cooking chamber together with the airflow generated by the fan; this airflow creates an overpressure within the cooking chamber, generating an airflow within the vapour outlet duct. For this reason, in known solution the cleaning of the cooking chamber and the cleaning of the vapour outlet duct can't be performed contemporaneously, otherwise the airflow generated in the vapour outlet duct by the fan could drag part of the jet of cleaning liquid sprayed by the nozzle in the vapour outlet duct out of the latter, with above mentioned problems. Therefore, cleaning process in these known solutions is rather time consuming, requiring to clean the cooking chamber and the vapour outlet duct at different times.
The aim of the invention is therefore to provide a cooking oven provided with a cleaning system allowing to clean the vapour outlet duct in an effective way, and without the need of frequent and burdensome maintenance of the cleaning system.
Within this aim, another object of the invention is to provide a cooking oven provided with a cleaning system allowing to reduce the time required for cleaning the cooking oven with respect to the known solutions.
Applicant has found that by using a vapour outlet duct provided with an internal surface having a circular, or substantially circular, or oval, or substantially oval, cross section, and a cleaning system comprising a vapour outlet duct cleaning pipe configured emitting within the vapour outlet duct a flow of cleaning liquid generating a swirl of cleaning liquid flowing on the internal surface of the vapour outlet duct, all of most of such internal surface is effectively touched, and therefore cleaned, by the cleaning liquid.
It is underlined that the expression "cleaning liquid" can indicate any kind of liquid that can be used during the cleaning procedure or method of the cooking oven, for example a washing liquid (e.g. water or water mixed with a washing additive), a rinsing liquid (e.g. water or water mixed with a rinsing additive), a descaling liquid etc.
Since the cleaning liquid flows swirling on the internal surface of the vapour outlet duct, such a liquid tends to adhere to the internal surface, and therefore it is quite unluckily that it can be dragged out of the vapour outlet duct by airflow flowing in the duct during the swirl; this allows performing the cleaning of the cooking chamber (which is done preferably while operating the fan of the cooking oven) and the cleaning of the vapour outlet duct contemporaneously (so reducing the overall time required for cleaning the oven), without the risk that the airflow generated in the vapour outlet duct by the operating fan could drag part of the cleaning liquid delivered in the vapour outlet duct out of the latter.
In particular, above aim and objects are solved by a cooking oven for foodstuffs comprising:

a cooking chamber, wherein foodstuffs can be placed for being cooked,
a vapour outlet duct configured for discharging vapour from the cooking chamber to the external of the cooking oven,
a cleaning system for cleaning the cooking oven, comprising a vapour outlet duct cleaning pipe configured for taking a cleaning liquid within the vapour outlet duct,

Advantageously, the vapour outlet duct cleaning pipe is configured for emitting within the vapour outlet duct the flow of cleaning liquid tangent or substantially tangent to the internal surface of the vapour outlet duct.
Preferably, the vapour outlet duct cleaning pipe is positioned partially outside the vapour outlet duct, and comprises an end portion positioned within the vapour outlet duct, and at least partially tangent to the internal surface of the latter, so that the flow of cleaning liquid exiting this end portion is tangent or substantially tangent to such internal surface.
Since the end portion of the vapour outlet duct cleaning pipe is tangent to the internal surface of the vapour outlet duct, it only slightly affects the vapour flow during the cooking process. More preferably, the end portion is inclined downwards with respect to an operative position of the cooking oven, so that a flow of cleaning liquid is directed downwards as it exits the end portion.
This particular positioning of the end portion favours the formation of a swirl of cleaning fluid on the internal surface of the vapour outlet duct.
It is underlined that in the present application "operative position", is defined as a position in which the oven is installed to be operated, and it lies in a horizontal, or substantial horizontal, plane such as the floor of a room, or the internal bottom wall of a piece of furniture in which the oven is built-in.
In an advantageous embodiment, the cleaning system comprises a circulation system configured for pumping liquid out of the cooking chamber and for pumping such liquid, or a part thereof, again in the cooking chamber, wherein the vapour outlet duct cleaning pipe is fluidly connected to the circulation system and is arranged for taking a liquid flowing through the latter into the vapour outlet duct.
More preferably, the circulation system comprises a circulation pump, an aspiration conduit connecting the circulation pump to a cooking chamber outlet provided in the cooking chamber, and a delivery conduit connecting the circulation pump to a washing/rinsing liquid circulation outlet provided in the cooking chamber and configured for allowing washing/rinsing liquid to enter the cooking chamber, wherein the vapour outlet duct cleaning pipe is fluidly connected to the delivery conduit, so as to take at least a part of washing/rinsing liquid flowing into the latter into the vapour outlet duct.
Still more preferably, the circulation system is configured for delivering a washing/rinsing liquid in parallel to the vapour outlet duct cleaning pipe and to the washing/rinsing liquid circulation outlet.
Preferably, the vapour outlet duct comprises:

a bottom region, positioned, in the operative position of the cooking oven, at least partially below the cooking chamber, and fluidly connected downstream of a cooking chamber outlet provided in the cooking chamber,
an end region protruding upwards from the bottom region, from which vapour is released to the external of the cooking oven,

In an advantageous embodiment, the cooking oven comprises a further outlet duct cleaning pipe configured for emitting within the vapour outlet duct a further flow of cleaning liquid generating a further swirl of cleaning liquid flowing on the internal surface of the vapour outlet duct.
Preferably, the further outlet duct cleaning pipe is configured for emitting within the vapour outlet duct the further flow of cleaning liquid tangent or substantially tangent to the internal surface of the vapour outlet duct.
Still preferably, the further vapour outlet duct cleaning pipe is positioned partially outside the vapour outlet duct, and comprises an end portion positioned within the vapour outlet duct, and at least partially tangent to the internal surface of the latter, so that the further flow of cleaning liquid exiting the end portion of the further vapour outlet duct cleaning pipe is tangent or substantially tangent to the internal surface.
Preferably, the end portion of the further outlet duct is inclined downwards with respect to an operative position of the cooking oven, so that the further flow of cleaning liquid is directed downwards as it exits such an end portion.
Preferably, the further vapour outlet duct cleaning pipe is fluidly connected to the circulation system and is arranged for taking a liquid flowing through the latter into the vapour outlet duct.
More preferably, the cooking oven comprises washing/rinsing additive supplying system configured for supplying washing and/or rinsing additives to the internal of the cooking chamber, wherein the further vapour outlet duct cleaning pipe is fluidly connected to the washing/rinsing additive supplying system, so as to take a washing and/or rinsing additive contained therein to the vapour outlet duct.
Preferably, the washing/rinsing additive supplying system comprises an additive drawer, loadable with a washing/rinsing additive and selectively fluidly connected or connectable to the circulation system in such a way to selectively supply a washing and/or rinsing additive to the latter.
More preferably, the additive drawer, is selectively fluidly connected or connectable to the aspiration conduit and/or delivery conduit of the circulation system.
Advantageously, the vapour outlet duct cleaning pipe can be fluidly connected, directly, or via a further component (e.g. one or more pipes, a drawer, a reservoir, etc.), to the additive drawer.
Advantageously, the further vapour outlet duct cleaning pipe can be fluidly connected to the additive drawer.
More preferably, the further vapour outlet duct cleaning pipe is fluidly connected to the aspiration duct of the circulation system via the drawer.
In a further advantageous embodiment, the cleaning system comprises a washing/rinsing additive multi-dosing system configured for supplying to the internal of the cooking chamber metered amounts of washing and/or rinsing additives
Advantageously, the vapour outlet duct cleaning pipe can be fluidly connected, directly, or via a further component (e.g. one or more pipes, a drawer, a reservoir, etc.), to the multi-dosing system.
Advantageously, the further vapour outlet duct cleaning pipe can be connected to the washing/rinsing additive multi-dosing system.
Advantageously, the further vapour outlet duct cleaning pipe can be connected to the washing/rinsing additive multi-dosing system directly or via the additive drawer.
It is underlined that a washing additive can be, for example, a detergent, while a rinsing additive can be for example a descaling additive, a brightener, etc.
Preferably, the cooking oven according to the invention comprises a first cooking chamber outlet positioned in such a way to receive grease collected in the bottom wall.
Preferably, the cooking oven according to the invention comprises a grease conduit configured for draining grease from the cooking chamber.
Preferably, the first cooking chamber outlet is fluidly connected to the grease conduit.
Preferably, the cooking oven according to the invention comprises a heating device configured for heating the internal of the cooking chamber.
Preferably, the cooking oven according to the invention comprises a second cooking chamber outlet, preferably provided on the bottom wall of the cooking chamber; preferably, the second cooking chamber outlet is distinct from the first cooking chamber outlet and it is fluidly connected to the vapour outlet duct.
It is underlined that, since both the cooking chamber outlet are positioned in the bottom of the cooking chamber, their impact on the thermal uniformity within the cooking chamber, and in particular in the region where foodstuff is placed, is very small.
Preferably, the first cooking chamber outlet, i.e. the one connected to the grease conduit, and the second cooking chamber outlet, i.e. the one connected to the vapour outlet duct, are reciprocally positioned and/or arranged, in such a way that the grease collected in the bottom wall of the cooking chamber enters firstly/more easily the first cooking chamber outlet than the second cooking chamber outlet, so that the possibilities that the grease enters the second cooking chamber outlet are highly reduced.
For example, in an advantageous embodiment, the inlet border of the second cooking chamber outlet can be placed at a raised position with respect to the inlet border of the first cooking chamber outlet; this preferred positioning of the inlet border of the second cooking chamber outlet guarantees that if the grease collects in the bottom wall of the cooking chamber, it enters firstly the first cooking chamber, and it is therefore drained to the grease conduit before reaching the level of the inlet border of the second cooking chamber outlet. In a further advantageous example, the bottom wall of the cooking chamber can be at least partially funnel-shaped, at least at or in proximity to the inlet border of the first cooking chamber outlet, so as to favour the drain of the grease collected in such a region to the first cooking chamber outlet.
Anyway other possible solutions can be used for forcing the grease collected in the bottom wall of the cooking chamber to enter firstly/more easily the first cooking chamber outlet than the second cooking chamber outlet; for example obstacles (e.g. protrusions) can be provided in the bottom wall of the cooking chamber, positioned in such a way to hinder the flow of the grease towards the second cooking chamber outlet and/or to and or to divert the flow towards the first cooking chamber outlet.
In a preferred embodiment, the bottom wall of the cooking chamber has a region, preferably centrally positioned, which is basin-shaped.
More preferably, the first cooking chamber outlet is positioned centrally with respect to this basin-shaped region.
Preferably, if the trays or racks are provided, the first cooking chamber outlet is positioned centrally with respect to overlying trays or racks, so as to effectively receive grease dripping from the foodstuff positioned on these trays or racks.
In a preferred embodiment, the cooking oven comprises a shield element arranged for preventing grease, in particular grease falling from the overlying foodstuff being cooked, from entering the second cooking chamber outlet.
More preferably, the shield element is positioned over the second cooking chamber outlet, spaced apart from the inlet border of the latter.
Even more preferably, the shield element protrudes from a lateral wall of the cooking chamber.
Preferably, the shield element can be fixed to the lateral wall of the cooking chamber for example by welding and or screwing, and or bolts, etc.
In an advantageous embodiment, the shield element can have a convex shape, preferably a reversed V-shaped cross section, so as to deflect away from the underlying second cooking chamber outlet the grease droplets falling from the foodstuff being cooked. Advantageously, the vapour outlet duct comprises a vapour outlet valve, for selectively opening/closing the vapour outlet duct, so as to regulate the discharge of the vapour in the external environment.
Advantageously, the cooking oven comprises an oven outlet, configured for draining liquid outside the cooking oven.
Preferably, the oven outlet is provided with an air trap.
In an advantageous embodiment, the grease conduit is selectively connected or connectable to a grease container.
Preferably, the grease conduit is selectively connected or connectable to the grease container via a first valve.
Preferably, the grease conduit is configured for draining grease exiting the first cooking chamber outlet by gravity.
It is underlined, that in the present application "by gravity" means due only to the gravity force, so without the need of a dedicated fluid moving device, like for example a pump. For example, stating that "the grease conduit is configured for draining grease exiting the first cooking chamber outlet by gravity" means that grease exiting the cooking chamber outlet is taken from the inlet to the outlet of the grease conduit due only to the effect of the gravity force, for example since the inlet is positioned higher than the outlet.
In a preferred embodiment, the grease conduit is oriented vertically, or substantially vertically, when the cooking oven is in its operative position.
In an advantageous embodiment, the cooking oven comprises a vortex preventing device positioned at the first cooking chamber outlet and/or in the grease conduit, and configured for hindering the formation of vortexes in a stream of liquid exiting the cooking chamber via the first cooking chamber outlet.
The vortex preventing device hinders the formation of vortexes in the liquid flow exiting the cooking chamber through the first cooking chamber outlet.
Preferably, a vortex preventing device can be provided also at the second cooking chamber outlet.
Advantageously, the vortex preventing device is an insert having preferably a cross-shaped, or star-shaped cross section, in which a plurality of wings are advantageously defined. Advantageously, these wings partialize the opening of the first cooking chamber outlet, hindering the formation of vortexes in the liquid flow exiting the cooking chamber through the first cooking chamber outlet.
Advantageously, the vortex preventing device is form-fitted within the first cooking chamber outlet.
In a preferred embodiment, the first cooking chamber outlet is fluidly connected, in addition to the grease conduit, to the oven outlet.
In a further preferred embodiment, the first cooking chamber outlet is fluidly connected, in addition to the grease conduit, to the circulation system.
In a further preferred embodiment, the second cooking chamber outlet is fluidly connected, in addition to the vapour outlet duct, to the oven outlet.
In a further preferred embodiment, the second cooking chamber outlet is fluidly connected, in addition to the vapour outlet duct, to the grease conduit.
In a further preferred embodiment, the second cooking chamber outlet is fluidly connected to the grease conduit via a connection duct whose end portion protrudes within the grease conduit, substantially perpendicularly to the internal surface of the latter.
This advantageous positioning of the end portion hinders the entrance of grease flowing within the grease conduit by gravity into the end portion; in fact, such a grease flowing in the grease conduit, abuts perpendicularly the external lateral wall of the end portion of the connection duct, and it is very difficult that it can enter the end portion, which requires a longitudinal entrance.
In a preferred embodiment, the second cooking chamber outlet is fluidly connected, in addition to the vapour outlet duct, to the circulation system.
Preferably, the first cooking chamber outlet and the second cooking chamber outlet are selectively connected to the oven outlet via a second valve.
In an advantageous embodiment, the cleaning system comprises a washing/rinsing liquid introduction system configured for taking washing/rinsing liquid within the cooking chamber.
It is underlined that a washing liquid can be for example water and/or water containing a detergent, while a rinsing liquid can be, for example water and/or water containing a descaling additive, or a brightener.
More preferably, the washing/rinsing liquid introduction system comprises an introduction conduit fluidly connected to the cooking chamber and configured for selectively supplying into the latter washing and/or rinsing liquid.
In a further preferred embodiment, the washing/rinsing liquid introduction system comprises a third valve for controlling the supply of washing and/or rinsing liquid through the introduction conduit.
In an advantageous embodiment, the washing/rinsing liquid circulation outlet and/or the outlet of the introduction conduit are positioned in an upper wall of the cooking chamber. In an advantageous embodiment, the outlet of the introduction conduit is separated from the washing/rinsing liquid circulation outlet.
In a further advantageous embodiment, the outlet of the introduction conduit into the cooking chamber coincides with the washing/rinsing liquid circulation outlet.
In a further advantageous embodiment, the aspiration conduit is fluidly connected to the second cooking chamber outlet via a by-pass conduit fluidly connecting the aspiration conduit to the vapour outlet duct, to which the second cooking chamber outlet is fluidly connected.
In a further advantageous embodiment, the by-pass conduit is fluidly connected to the grease conduit.
Preferably, the by-pass conduit is fluidly connected to the grease conduit via the above-mentioned connection duct.
Preferably, the cooking oven comprises a drain conduit fluidly connecting the oven outlet to the first cooking chamber outlet and to the second cooking chamber outlet.
More preferably, the drain conduit is fluidly connected to the oven outlet via the second valve.
Still more preferably, the aspiration conduit is selectively fluidly connected to the oven outlet via the drain conduit.
Preferably, the by-pass conduit is selectively fluidly connected to the oven outlet via the drain conduit.
Preferably, the grease conduit is selectively fluidly connected to the oven outlet via the drain conduit.
In an advantageous embodiment, the cooking oven comprises a quenching system for cooling down steam exiting from the cooking chamber.
Preferably, the quenching system comprises a quenching conduit for supplying cooling liquid within the vapour outlet duct.
In a preferred embodiment, the quenching conduit comprises an inlet positioned, in the operative position of the cooking oven, at a higher level with respect to the maximum level that washing/rinsing liquid can reach within the cooking chamber during the washing procedure of the cooking oven; this ensures that, even if washing/rinsing liquid should flow back through the quenching conduit, it wouldn't exit the latter with the risk of contaminating the water mains.
Preferably, the quenching conduit comprises an outlet positioned within the bottom region of the vapour outlet duct; in this way quenching liquid is released in the vapour outlet duct quite far away from its end region. This arrangement of the outlet prevents that quenching liquid (e.g. water) exiting the quenching conduit is taken out of the vapour outlet duct due to the flow of vapour flowing therein.
Preferably, the bottom region of the vapour outlet duct is slightly inclined in such a way that liquid contained therein tends to flow, by gravity, in counter-current with respect to the vapour.
In a preferred embodiment, the by-pass conduit is connected to the vapour outlet duct at or in proximity to the initial region of the bottom region so that, due to the slope of the latter, condensed liquid present in such a bottom region flows by gravity into the by-pass conduit. In an advantageous embodiment, the outlet of the quenching conduit comprises a quenching nozzle arranged within the bottom region and configured for spraying a jet of water against the vapour exiting the second cooking chamber outlet.
Advantageously, the cooking oven comprises a fourth valve for controlling the supply of cooling water through the quenching conduit.
Advantageously, the cooking oven comprises a perforated suction wall separating the cooking chamber from a heating chamber containing at least partially the heating device and a fan, wherein the fan is configured for circulating heated air through the cooking chamber and the heating chamber.
In an advantageous embodiment, the cooking oven comprises a ventilation pipe fluidly connected to the cooking chamber and configured for selectively taking air from the external environment into the cooking chamber.
Preferably, the ventilation pipe comprises an outlet provided at the heating chamber. More preferably, the ventilation pipe is provided with a ventilation valve for selectively closing the ventilation pipe.
In an advantageous embodiment, the cooking oven comprises an overflow conduit directly fluidly connecting the vapour outlet duct to the oven outlet, and configured for directly discharging to the oven outlet the liquid present in the vapour outlet duct only if the level of the liquid in the vapour outlet duct exceeds a certain height.
In an advantageous embodiment, the circulation system is fluidly connected to the vapour outlet duct, and it is configured for taking washing/rinsing liquid from said cooking chamber into the vapour outlet duct, so as to wash the latter.
Still more preferably, the cooking oven comprises a fifth valve for connecting the additive drawer to water supply mains.
In a further advantageous embodiment, the cooking oven comprises a sixth valve selectively connecting the additive drawer to the aspiration conduit and/or delivery conduit. Preferably, the washing/rinsing additive multi-dosing system comprises:

one or more washing/rinsing additives containers filled or fillable with an amount of washing and/or rinsing additives sufficient for a plurality of washing/rinsing cycles;
one or more washing/rinsing additives delivery conduits fluidly connecting such one or more washing/rinsing additives containers to the internal of the cooking chamber;
one or more washing/rinsing additives pumps, configured for pumping a washing/rinsing additive out of the one or more washing/rinsing additives containers and delivery the washing/rinsing additives to the cooking chamber via one or more washing/rinsing additives delivery conduits.

In an advantageous embodiment, at least one of the one or more washing/rinsing additives containers is fluidly connected to the additive drawer.
In a further preferred embodiment, at least one of the one or more washing/rinsing additives containers is fluidly connected to the washing/rinsing liquid introduction system.
More preferably all the one or more washing/rinsing additives containers are fluidly connected to the introduction conduit.
Advantageously, the cooking oven comprises a steam supply system configured for producing and supplying steam into the cooking chamber.
Preferably, the steam supply system comprises a boiler configured for producing steam and fluidly connected to the cooking chamber so as to release into the latter the steam.
More preferably, the boiler comprises a water reservoir fillable with water, and a water heater for heating water loaded within the water reservoir.
In an advantageous embodiment, the steam supply system comprises:

a water inlet conduit fluidly connected to the water reservoir and connected or connectable to water mains,
a water outlet conduit fluidly connecting the water reservoir to the oven outlet.

Still preferably, the steam supply system comprises:

a sixth valve associated to the water inlet conduit for controlling the delivery of water to the water reservoir,
a eighth valve associated to the water outlet conduit for controlling the drain of liquid from the reservoir to the oven outlet.

Preferably, the steam supply system comprises a steam duct fluidly connecting the reservoir to the cooking chamber.
In an advantageous embodiment, the cleaning system is configured for supplying a washing/rinsing liquid to the steam supply system.
Preferably, the cleaning system is configured for supplying a washing/rinsing liquid to the boiler.
Preferably, the cleaning system comprises a boiler cleaning conduit, fluidly connecting the washing/rinsing additive supplying system to the boiler.
More preferably, the boiler cleaning conduit fluidly connects the water reservoir to the additive drawer.
Still preferably, the boiler cleaning conduit fluidly connects the water reservoir to the washing/rinsing additive multi-dosing system.
More preferably, the boiler cleaning conduit fluidly connects the water reservoir to one or more of said the or more washing/rinsing additives container.
Preferably, the cooking oven comprises an electronic controller, for example a programmed/programmable electronic board, for controlling one or more (preferably all the) functions of the cooking oven (e.g. the cooking procedure, the washing procedure, the electronic controllable components, etc.).
The invention is also related to a method for cleaning a cooking oven according to the invention, comprising the following steps:

taking a cleaning liquid within the vapour outlet duct cleaning pipe;
emitting a flow of this cleaning liquid within the vapour outlet duct via the vapour outlet duct cleaning pipe in such a way to generate a swirl of cleaning liquid flowing on the internal surface of the vapour outlet duct having a circular, or substantially circular, or oval, or substantially oval, cross section.

These and other features and advantages of the invention will be better apparent from the following description of some exemplary and non-limitative embodiments, to be read with reference to the attached drawings, wherein:

Fig. 1 is a schematic frontal view of a cooking oven according to the invention;
Fig. 2 is a schematic lateral view, with some parts removed for more clarity, of a first embodiment of a cooking oven according to the invention;
Fig. 3 is a schematic lateral view, with some parts removed for more clarity, of a second embodiment of a cooking oven according to the invention;
Fig. 4 is a schematic lateral view, with some parts removed for more clarity, of a third embodiment of a cooking oven according to the invention;
Fig. 5 is a schematic lateral view, with some parts removed for more clarity, of a fourth embodiment of a cooking oven according to the invention;
Fig. 6 is a schematic lateral view, with some parts removed for more clarity, of a fifth embodiment of a cooking oven according to the invention;
Fig. 7 is a detail of an advantageous embodiment of the first cooking chamber outlet of a cooking oven according the invention, in which a vortex preventing device is visible;
Fig. 8 is a detail of a schematic lateral view of the bottom region of the cooking chamber of an advantageous embodiment of a cooking oven according to the invention,
Fig. 9 is a plan view of the vapour outlet duct of a cooking oven according to the invention,
Fig. 10 is a cross section according to plane X-X of Fig. 9;
Fig. 11 is a cross section of the vapour outlet duct according to a further advantageous embodiment of the invention;
Fig. 12 is a schematic flow chart of a first embodiment of a cleaning method of an oven according to the invention;
Fig. 13 is a schematic flow chart of a second embodiment of a cleaning method of an oven according to the invention.

With reference initially to Fig. 1, a cooking oven 1 according to the invention is schematically described.
It is underlined that all the functions of the oven can be advantageously controlled by a suitable electronic controller, for example a programmed/programmable electronic board, schematically illustrated in figure 1 by a dashed square 600.
The cooking oven comprises an external casing 200, containing a cooking chamber 2, wherein foodstuffs can be placed for being cooked; preferably, the cooking chamber is accessible via a door 2a.
In an advantageous embodiment, like in the examples of attached figures, the cooking chamber 2 contains a plurality of trays or racks 2b, wherein foodstuff, or pots or trays containing foodstuff, can be placed for being cooked.
The cooking chamber 2 has a bottom wall 3, preferably, but not necessarily, at least partially, basin-shaped, so as to better collect grease dripping from the foodstuffs being cooked. Advantageously, the bottom wall 3 is provided with a first cooking chamber outlet 4 positioned in such a way to receive grease or liquid dripped from the foodstuff being cooked and collected in the bottom wall 3.
In the advantageous examples illustrated in attached figures, the bottom wall 3 has a region 3a, preferably centrally positioned, which is basin shaped; in this advantageous example, the first cooking chamber outlet 4 is positioned centrally with respect to this basin-shaped region 3a. More preferably, the region 3a is at least partially funnel-shaped, at least at or in proximity to the inlet border 4a of first cooking chamber outlet 4, so as to favour the drain of the grease collected on such a region 3a to the first cooking chamber outlet 4. Preferably, if the trays or racks 2b are provided, the first cooking chamber outlet 4 is positioned centrally with respect to overlying trays or racks 2b, so as to effectively receive grease dripping from the foodstuff positioned on these trays or racks 2b.
The oven 1 also comprises a grease conduit 6 configured for draining grease from the cooking chamber 2; the first cooking chamber outlet 4 is fluidly connected to the grease conduit 6.
Advantageously, the grease conduit 6 is selectively connected or connectable to a grease container 60, positioned preferably outside the oven 1, and more preferably removable, in such a way that, when full, it can be removed for being emptied, and/or it can be replaced by an empty one.
In an advantageous embodiment, the grease conduit 6 is selectively connected or connectable to the grease container 60 via a first valve 11, that can be selectively opened and closed, automatically and/or manually, in order to allow grease dripping from the foodstuff to be collected in the grease container 60.
In a preferred embodiment, the grease conduit 6 is configured for draining grease exiting the first cooking chamber outlet 4 by gravity.
It is underlined, that in the present application "by gravity" means due only to the gravity force, so without the need of a dedicated fluid moving device, like for example a pump.
For example, stating that "the grease conduit is configured for draining grease exiting the first cooking chamber outlet by gravity" means that grease exiting the cooking chamber outlet is taken from the inlet to the outlet of the grease conduit due only to the effect of the gravity force, for example since the inlet is positioned higher than the outlet.
This can be obtained, for example, by orienting the grease conduit 6 vertically, or substantially vertically, when the cooking oven 1 is in its operative position.
It is underlined that in the present application "operative position", is defined as a position in which the oven is installed to be operated, and it lies in a horizontal, or substantial horizontal, plane such as the floor of a room, or the internal bottom wall of a piece of furniture in which the oven is built-in.
Advantageously, the cooking oven further comprises a heating device 8 configured for heating the internal of the cooking chamber 2; the heating device 8 can be an electrical heater, or (as in the examples illustrated in attached figures) hot tubes wherein the hot fumes exiting a gas burner flows, a heat exchanger, etc.
Advantageously, the cooking oven 1 comprises a perforated suction wall 18 separating the cooking chamber 2 from a heating chamber 19 containing, at least partially, the heating device 8, and, preferably, a fan 20 configured for circulating heated air through the cooking chamber 2 and the heating chamber 19.
The cooking oven 1 comprises a vapour outlet duct 9 configured for discharging vapour from the cooking chamber 2; the vapour outlet duct 9 can advantageously discharge the vapour in the external environment around the cooking oven 1, or it can be advantageously connected to a vapour discharge system, not illustrated, preferably provided in the building where the cooking oven 1 is installed.
Advantageously, the vapour outlet duct 9 comprises an internal surface 90 having a circular, or substantially circular, or oval, or substantially oval, cross section.
Preferably, the bottom wall 3 of the cooking chamber 2 is provided with a second cooking chamber outlet 10, more preferably distinct from the first cooking chamber outlet 4, fluidly connected to the vapour outlet duct 9.
In a further advantageous embodiment, not illustrated the first and second cooking chamber outlet can coincide.
Vapour present the cooking chamber 2, for example emitted from the foodstuff, and/or (like in the advantageously embodiments of figures 3 and 4) due to steam supplied in the cooking chamber 2 by a steam supply system 35, if the cooking oven is advantageously provided with such a steam supply system 35, is therefore discharged outside the cooking oven 1, advantageously passing through the second cooking chamber outlet 10 and the vapour outlet duct 9.
Preferably, the first cooking chamber outlet 4 and the second cooking chamber outlet 10 are positioned on the bottom wall 3, and are reciprocally positioned and/or arranged, in such a way that the grease collected in the bottom wall 3 enters firstly/more easily the first cooking chamber outlet 4 than the second cooking outlet chamber 10, so that the possibilities that the grease enters the second cooking chamber outlet 10 are highly reduced.
This can be obtained for example, in advantageous embodiments, like in the examples illustrated in attached figures, if the inlet border 10a of the second cooking chamber outlet 10 is placed at a raised position with respect to the inlet border 4a of the first cooking chamber outlet 4; in this way the grease collected in the bottom 3 goes firstly into the first cooking chamber outlet 4, and therefore the possibilities that its level increases enough to enter the first cooking chamber outlet 10 are highly reduced.
In a further advantageous embodiment, like in the example of Figure 8, the cooking oven 1 can comprise a shield element 300 for preventing grease, in particular grease falling from the overlying foodstuff being cooked, from entering the second cooking chamber outlet 10. Preferably, the shield element 300 is positioned over the second cooking chamber outlet 10, spaced apart from the inlet border 10a of the latter.
More preferably, the shield element 300 protrudes from the lateral wall of the cooking chamber 2; advantageously the shield element 300 can be fixed to the lateral wall of the cooking chamber for example by welding and or screwing, and or bolts, etc.
In an advantageous embodiment, the shield element 300 can have a convex, preferably reversed V-shaped, cross section, so as to deflect away from the underlying second cooking chamber outlet 10 the grease droplets falling from the foodstuff being cooked.
In the advantageous embodiments illustrated in attached figures, the cooking oven 1 comprises a cleaning system 70.
Preferably, the cleaning system 70 comprises a circulation system 7 configured for pumping liquid out of the cooking chamber 2 and for pumping such liquid, or a part thereof, again in the cooking chamber 2.
In preferred embodiments, like for example the ones illustrated in attached figures, the circulation system 7 comprises a circulation pump 7a, an aspiration conduit 7b connecting the circulation pump 7a to the first cooking chamber outlet 4 and/or to the second cooking chamber outlet 10, and a delivery conduit 7c connecting the circulation pump 7a to a washing/rinsing liquid circulation outlet 13 provided in the cooking chamber 2 and configured for allowing washing/rinsing liquid to enter the cooking chamber 2.
It is underlined that a washing liquid can be for example water and/or water containing a detergent, while a rinsing liquid can be, for example water and/or water containing a descaling additive or a brightener.
In an advantageous embodiment, like in the examples illustrated in attached figures, the aspiration conduit 7b fluidly connects the circulation pump 7a both to the first cooking chamber outlet 4 and to the second cooking chamber outlet 10.
Advantageously, the cleaning system comprises a vapour outlet duct cleaning pipe 450 configured for taking a cleaning liquid within the vapour outlet duct 9, and in particular for emitting within the vapour outlet duct 9 a flow of cleaning liquid 451 generating a swirl of cleaning liquid 452 flowing on the internal surface 90.
Advantageously, the vapour outlet duct cleaning pipe 450 is configured for emitting within the vapour outlet duct 9 the flow of cleaning liquid 451 tangent or substantially tangent to the internal surface 90 of the vapour outlet duct 9.
As illustrated for example in figures 9 and 10, the vapour outlet duct cleaning pipe 450 is positioned partially outside the vapour outlet duct 9, and comprises an end portion 453 positioned within the vapour outlet duct 9, and at least partially tangent to the internal surface 90 of the latter, so that the flow of cleaning liquid 451 exiting the end portion 453 is tangent or substantially tangent to the internal surface 90.
Advantageously, as illustrated for example in attached figures, the end portion 453 is inclined downwards with respect to the operative position of the cooking oven 1, so that a flow of cleaning liquid 451 is directed downwards as it exits the end portion 453. Advantageously, the outlet duct cleaning pipe 450 is fluidly connected to the circulation system 7 and is arranged for taking a liquid flowing through the latter into the vapour outlet duct 9.
More advantageously, the vapour outlet duct cleaning pipe 450 is fluidly connected to the delivery conduit 7c of the circulation system 7, so as to take at least a part of washing/rinsing liquid flowing into the latter into the vapour outlet duct 9.
Advantageously, as in the examples illustrated in attached figures, the circulation system 7 is configured for delivering a washing/rinsing liquid in parallel to the vapour outlet duct cleaning pipe 450 and to the washing/rinsing liquid circulation outlet 13.
In an advantageous embodiment, like in the examples illustrated in attached figures, the cooking oven 1 comprises a vortex preventing device 100 positioned at the first cooking chamber outlet 4 and/or in the grease conduit 6, and configured for hindering the formation of vortexes in a stream of liquid exiting the cooking chamber 2 via the first cooking chamber outlet 4.
Advantageously, the vortex preventing device 100 can be an insert having preferably a cross-shaped, or star-shaped cross section, in which a plurality of wings 100a are advantageously defined, preferably form fitted within the first cooking chamber outlet 4; wings 100a partialize the opening of the first cooking chamber outlet 4, hindering the formation of vortexes in the liquid flow exiting the cooking chamber 2 through the first cooking chamber outlet 4.
Absence of vortexes is very important in the advantageous embodiments in which the oven is provided with above described circulation system 7, since vortexes could form bubbles that prevent the circulation pump 7a to prime properly.
In a further embodiment, not illustrated, a vortex preventing device 100 is positioned also at the second cooking chamber outlet 10.
Advantageously, the cooking oven 1 comprises an oven outlet 5, configured for draining liquid outside the cooking oven 1; advantageously the oven outlet 5 can be connected to the sewage pipes, not illustrated, of the building in which the cooking oven 1 is installed. Preferably, the first cooking chamber outlet 4 is fluidly connected, in addition to the grease conduit 6, also, preferably selectively, to the oven outlet 5.
Advantageously, the oven outlet 5 is provided with an air trap 5a, for preventing, when active (i.e. when filled with a liquid), gas to exit through said oven outlet 5.
In the advantageous embodiment in which the cooking oven 1 is provided with the circulation system 7, as in the examples of attached figures, the first cooking chamber outlet 4 can be fluidly connected to the circulation system 7.
In an advantageous embodiment, as in the examples of attached figures, the second cooking chamber outlet 10 is fluidly connected, in addition to the vapour outlet duct 9, to the oven outlet 5.
Preferably, the first cooking chamber outlet 4 and the second cooking chamber outlet 10 are selectively connected to the oven outlet 5 via a second valve 12, which can be manual or automatic.
Advantageously, the cooking oven 1 comprises a drain conduit 5b fluidly connecting the oven outlet 5 to the first cooking chamber outlet 4 and, preferably, to the second cooking chamber outlet 10.
Advantageously, the drain conduit 5b is fluidly connected to the oven outlet 5 via the second valve 12.
In a preferred embodiment, the second cooking chamber outlet 10 is fluidly connected, in addition to the vapour outlet duct 9, to the grease conduit 6.
In a preferred embodiment, the second cooking chamber outlet 10 is fluidly connected to the grease conduit 6 via a connection duct 50 whose end portion 50a protrudes within the grease conduit 6, substantially perpendicularly to the internal surface of the latter.
This positioning of the end portion 50a hinders the entrance of grease flowing within the grease conduit 6 by gravity into the end portion 50a; in fact, such a grease, flowing in the grease conduit 6, abuts perpendicularly against the external lateral wall of the end portion 50a of the connection duct 50, and it is very difficult that it can enter the end portion 50a which requires a longitudinal entrance.
Preferably, the aspiration conduit 7b of the circulation system 7 is fluidly connected to the second cooking chamber outlet 10 via a by-pass conduit 14 fluidly connecting the aspiration conduit 7b to the vapour outlet duct 9, to which the second cooking chamber outlet 10 is fluidly connected.
More preferably, the by-pass conduit 14 is fluidly connected to the grease conduit 6.
Even more preferably, the by-pass conduit 14 is fluidly connected to the grease conduit 6 via above described connection duct 50.
Advantageously, the aspiration conduit 7b of the circulation system 7 is selectively fluidly connected to the oven outlet 5 via the drain conduit 5b.
Advantageously, the by-pass conduit 14 is selectively fluidly connected to the oven outlet 5 via the drain conduit 5b.
Advantageously, the grease conduit 6 is selectively fluidly connected to the oven outlet 5 via the drain conduit 5b.
In an advantageous embodiment, the cleaning system 70 comprises a washing/rinsing liquid introduction system 16 configured for taking washing/rinsing liquid within the cooking chamber 2.
In an advantageous embodiment, the washing/rinsing liquid introduction system 16 comprises an introduction conduit 16a fluidly connected to the cooking chamber 2 and configured for selectively supplying into the latter washing and/or rinsing liquid.
In a preferred embodiment, the washing/rinsing liquid introduction system 16 comprises a third valve 16b for controlling the supply of washing and/or rinsing liquid through the introduction conduit 16a.
Advantageously, as in the examples illustrated in attached figures, the introduction conduit 16a can be connected, upstream the third valve, to water mains, not illustrated, provided in the building where the cooking oven 1 is installed.
Advantageously, the washing/rinsing liquid circulation outlet 13 and the outlet 16c of the introduction conduit 16a are positioned in an upper wall 23 of the cooking chamber 2. Preferably, the washing/rinsing liquid circulation outlet 13 and the outlet 16c of the introduction conduit 16a are positioned in an upper wall 23 of the cooking chamber 2, in proximity of the suction wall 18.
Preferably, the outlet 16c of the introduction conduit 16a is separated from the washing/rinsing liquid circulation outlet 3.
In a further advantageous embodiment, not illustrated, the outlet of the introduction conduit 16a into the cooking chamber 2 coincides with the washing/rinsing liquid circulation outlet 13.
Advantageously, the cooking oven 1 comprises a quenching system 17 for cooling down steam exiting from the cooking chamber 2.
Preferably, the quenching system 17 comprises a quenching conduit 17a for supplying a cooling liquid within the vapour outlet duct 9.
The quenching liquid is preferably fresh water, coming from the water mains, not illustrated, of the building in which the cooking oven 1 is installed, to which the quenching conduit 17a can be fluidly connected.
Advantageously, the quenching conduit 17a comprises an inlet 170a positioned, in the operative position of the cooking oven 1, at a higher level with respect to the maximum level 500 that washing/rinsing liquid can reach within the cooking chamber 2 during the washing procedure of the cooking oven 1.
This ensures that, even if washing/rinsing liquid should flow back through the quenching conduit 17a, it wouldn't exit the latter with the risk of contaminating the water mains.
In a preferred embodiment, as in the examples illustrated in attached figures, the vapour outlet duct 9 comprises a bottom region 9a, positioned, in the operative position of the cooking oven 1, at least partially below the cooking chamber 2, and fluidly connected downstream of said second cooking chamber outlet 10.
More preferably, as in the examples of the attached figures, the bottom region 9a of the vapour outlet duct 9 is slightly inclined in such a way that liquid contained therein tends to flow, by gravity, in counter-current with respect to the vapour flowing through the bottom region 9a; in other words, the bottom region 9a is preferably inclined in such a way to define a backwards slope.
In a preferred embodiment, the by-pass conduit 14 is connected to the vapour outlet duct 9 at or in proximity to the initial region of the bottom region 9a so that, due to the slope of the latter, condensed liquid present in such a bottom region 9a flows by gravity into the by-pass conduit 14.
Preferably, the vapour outlet duct 9 comprises an end region 9b protruding upwards from the bottom region 9a, from which vapour is released in the environment.
Advantageously, the end region 9b is substantially vertical.
In a preferred embodiment, the internal surface 90 having a circular, or substantially circular, or oval, or substantially oval, cross section of the vapour outlet duct 9 is comprised in the end region 9b of the latter.
Preferably, the quenching conduit 17a comprises an outlet 1710b positioned within the bottom region 9a of the vapour outlet duct 9; since in this way quenching liquid is released in the vapour outlet duct quite far away from its end region 9a, this arrangement of the outlet 170b prevents that quenching liquid (e.g. water) exiting the quenching conduit 17a is taken out of the vapour outlet duct 9 by the flow of vapour, schematically illustrated with dotted arrows 400 in attached figures, flowing therein.
Preferably, the outlet 170b of the quenching conduit 17a comprises a quenching nozzle, not illustrated, arranged within the bottom region 9a and configured for spraying a jet of water against the vapour exiting the cooking chamber outlet 10.
In an advantageous embodiment, the quenching system 17 comprises a fourth valve 17c for controlling the supply of cooling water through the quenching conduit 17a.
Preferably, as in the examples illustrated in attached figures, the cooking oven 1 comprises a ventilation pipe 21 fluidly connected to the cooking chamber 2 and configured for selectively taking air from the external environment into the cooking chamber 2. Preferably, the ventilation pipe 21 comprises an outlet 21a provided at the heating chamber 19, more preferably in proximity to the fan 20.
Advantageously, the ventilation pipe 21 is provided with a controlled ventilation valve 22 for selectively closing the ventilation pipe 21.
Preferably, the cooking oven 1 comprises an overflow conduit 26 directly fluidly connecting the vapour outlet duct 9 to the oven outlet 5, and configured for directly discharging to the oven outlet 5 liquid present in the vapour outlet duct 9 only if the level of such a liquid exceeds a certain height. Advantageously, such height corresponds to the maximum level 500 allowed for the liquid within the cooking chamber 2.
Advantageously, like in the examples of attached figures, the circulation system 7 is fluidly connected to the vapour outlet duct 9, and it is configured for taking washing/rinsing liquid from the cooking chamber 2 into the vapour outlet duct 9, so as to wash the latter. Advantageously, the cleaning system 70 comprises a washing/rinsing additive supplying system 27 configured for supplying washing and/or rinsing additives to the internal of the cooking chamber 2.
In a preferred embodiment, the washing/rinsing additive supplying system 27 comprises an additive drawer 28, loadable with a washing/rinsing additive, and selectively fluidly connected or connectable to the circulation system 7, in such a way to selectively supply a washing and/or rinsing additive into the latter, and preferably to the aspiration conduit 7b and/or delivery conduit 7c.
Preferably, the washing/rinsing additive comprises a descaling additive.
Preferably, the cooking oven 1 comprises a fifth valve 29 for connecting the additive drawer 28 to water supply mains.
Preferably, the cooking oven 1 comprises a sixth valve 30 selectively connecting the additive drawer 28 to the aspiration conduit 7b and/or delivery conduit 7c.
In a further advantageous embodiment, like in the examples illustrated in figures 4 to 6, the cleaning system 70 comprises a washing/rinsing additive multi-dosing system 31 configured for supplying to the internal of the cooking chamber 2 metered amounts of washing and/or rinsing additives.
Preferably, the washing/rinsing additive multi-dosing system 31 comprises:

one or more washing/ rinsing additives containers 32a, 32b filled or fillable with an amount of washing and/or rinsing additives sufficient for a plurality of washing/rinsing cycles;
one or more washing/rinsing additives delivery conduits 33a, 33b fluidly connecting such one or more washing/ rinsing additives containers 32a, 32b to the internal of the cooking chamber 2;
one or more washing/ rinsing additives pumps 34a, 34b, configured for pumping a washing/rinsing additive out of the one or more washing/ rinsing additives containers 32a, 32b and for delivering the washing/rinsing additives to the cooking chamber 2 via the one or more washing/rinsing additives delivery conduits 33a, 33b.

In advantageous embodiments, like the ones illustrated in the examples of figures 4 and 6, at least one of the one or more washing/rinsing additives containers 32a, 32bs (for example container 32a in figures 4 and 6) is fluidly connected to the additive drawer 28; in this way, the user can decide if using the cleaning system 70 as a "single dose" cleaning system, i.e. a system requiring to load the drawer 28 any time it has to be used (in this case the user uses the drawer 28 for loading the single dose of additive), or as a "multi-dose" system, i.e. a cleaning system in which the additive(s) have to be filled (or refilled), only sporadically, being enough for a plurality of washing/rinsing procedures.
Preferably, at least one of the one or more washing/ rinsing additives containers 32a, 32b is fluidly connected to the washing/rinsing liquid introduction system 16, preferably to the introduction conduit 16a.
In an advantageous embodiment, like for example the one illustrated in figure 5, all the washing/ rinsing additives containers 32a, 32b are fluidly connected to the introduction conduit 16a; in this case, the drawer 28 is preferably not provided, and the cleaning system 70 can be used only as a "multi-dose" system.
In advantageous embodiments, like for example the ones illustrated in figures 3 and 4, the cooking oven 1 comprises a steam supply system 35 configured for producing and supplying steam into the cooking chamber 2.
Advantageously the steam supply system 35 can comprise a boiler 36 configured for producing steam and fluidly connected to the cooking chamber 2 so as to release into the latter the steam.
Preferably, the boiler 36 comprises a water reservoir 37 fillable with water, and a water heater 38 for heating water loaded within the water reservoir 37.
Advantageously, the steam supply system 35 comprises:

a water inlet conduit 39 fluidly connected to the water reservoir 37 and connected or connectable to water mains,
a water outlet conduit 40 fluidly connecting the water reservoir 37 to the oven outlet 5. More preferably, the steam supply system 35 comprises:
a seventh valve 41 associated to the water inlet conduit 39 for controlling the delivery of water to the water reservoir 37,
a eight valve 42 associated to the water outlet conduit 40 for controlling the drain of liquid from the reservoir 37 to the oven outlet 5.

Preferably, the steam supply system 35 comprises a steam duct 43 fluidly connecting the reservoir 37 to the cooking chamber 2, for supplying the steam from the reservoir 37 into the latter.
In advantageous embodiments, like in the examples of figures 3 and 4, the cleaning system 70 is configured for supplying a washing/rinsing liquid to the boiler 36.
In advantageous embodiments, like the ones illustrated in figures 3 and 4, the cleaning system 70 comprises a boiler cleaning conduit 44, fluidly connecting the washing/rinsing additive supplying system 27 to the boiler 36.
Preferably, like in the example of figures 3 and 4, the boiler cleaning conduit 44 fluidly connects the water reservoir 37 to the additive drawer 28.
In an advantageous embodiment, like in the example of figure 4, the boiler cleaning conduit 44 fluidly connects the water reservoir 37 to the washing/rinsing additive multi-dosing system 31. In this case, the boiler cleaning conduit 44 can preferably fluidly connect the water reservoir 37 to one or more of the one or more washing/ rinsing additives container 32a, 32b.
In an advantageous embodiment, as for example in the embodiment illustrated in figures 6 and 11, the cooking oven 1 comprises a further outlet duct cleaning pipe 460 configured for emitting within the vapour outlet duct 9 a further flow 461 of cleaning liquid generating a further swirl 462 of cleaning liquid flowing on the internal surface 90.
Advantageously, also the further outlet duct cleaning pipe 460 is configured for emitting within the vapour outlet duct 9 the further flow of cleaning liquid 461 tangent or substantially tangent to the internal surface 90 of the vapour outlet duct 9.
Also the further vapour outlet duct cleaning pipe 460 is advantageously positioned partially outside the vapour outlet duct 9, and comprises an end portion 463 positioned within the vapour outlet duct 9, and at least partially tangent to the internal surface 90 of the latter, so that the further flow of cleaning liquid 461 exiting the end portion 463 of the further vapour outlet duct cleaning pipe 460 is tangent or substantially tangent to the internal surface 90. Also the end portion 463 of the further vapour outlet duct cleaning pipe 460 is inclined downwards with respect to an operative position of the cooking oven 1, so that a further flow of cleaning liquid is directed downwards as it exits such an end portion 463.
In an advantageous embodiment, like in the example of figure 6, the further vapour outlet duct cleaning pipe 460 is fluidly connected to the washing/rinsing additive supplying system 27, so as to take a washing and/or rinsing additive contained therein to the vapour outlet duct 9.
Advantageously, as in the example of figure 6, the further vapour outlet duct cleaning pipe 460 is fluidly connected to the additive drawer 28.
Preferably, the further vapour outlet duct cleaning pipe 460 is fluidly connected to the circulation system 7; in the advantageous example of figure 6, the further vapour outlet duct cleaning pipe 460 is fluidly connected to the aspiration duct 7b of the circulation system 7 via the drawer 28 and the sixth valve 30.
Advantageously, as in the example of figure 6, the further vapour outlet duct cleaning pipe 460 can be connected to the washing/rinsing additive multi-dosing system 31, for example via the drawer 28, or, in a further embodiment, not illustrated, directly.
In a further advantageous embodiment, the vapour outlet duct cleaning pipe 450 can be fluidly connected, directly, or via a further component (e.g. one or more pipes, a drawer, a reservoir, etc.), to the drawer 28 and/or to the multi-dosing system 31.
The functioning of the oven according to the invention will be explained in relation to the different embodiments illustrated in attached figures; it is underlined that figure 1 is a schematic illustration of the external shape of a possible embodiment of a cooking oven 1 according to the invention, which fits all the internal layouts illustrated in figures 2 to 6. Also figures 9 and 10 represent a layout of the vapour outlet duct 9 and vapour outlet duct cleaning pipe 450 fitting all the internal layouts illustrated in figures 2 to 6.
With reference to the embodiment of figure 2, once the foodstuff has been loaded into the cooking chamber 2, and the door 2a closed, the cooking process can be started; the heating device 8 and the fan 20 are operated, advantageously by the electronic controller 600 of the cooking oven 1, according to a specific cooking program selected and/or programmed by a user.
Also ventilation valve 22 is controlled, advantageously by the electronic controller 600 of the cooking oven 1, for keeping fresh air from the external environment into the cooking chamber 2, advantageously according to the specific cooking program selected and/or programmed by the user.
During the cooking process, the vapour present in the cooking chamber 2, and the high internal temperature, increase the internal pressure, and, when the latter exceeds ambient pressure, vapour is expelled to external of the cooking chamber 2 via the second cooking chamber outlet 10 and the vapour outlet duct 9.
It is underlined that the portion 453 of the vapour outlet duct cleaning pipe 450, being tangent to the internal surface 90 of the vapour outlet duct 9, does not substantially affect, or only marginally affects the flow of vapour through vapour outlet duct 9.
The quenching system 17, if provided, emits a jet of preferably fresh clean water, taken more preferably from external water mains, against the flow of vapour 400 flowing through the vapour outlet duct 9, cooling down and dehumidifying such a vapour ; condensate resulting from this quenching process is collected in the bottom region 9a of the vapour outlet duct 9, and, preferably due to its slope, it is taken by gravity to the by-pass conduit 14, from which it is taken, still by gravity, to the drain conduit 5b, and to the oven outlet 5, from where it can be drained to the sewage pipes, not illustrated, of the building in which the cooking oven 1 is installed.
Advantageously, before reaching the oven outlet 5, the condensate reaches the air trap 5a (if provided), activating the latter (if not already activated by liquid present in the latter from previous usages of the cooking oven), so that vapour can't exit through it.
If condensate level within the vapour outlet duct 9 exceed the level of the overflow conduit 26, it is drained by the latter directly to the oven outlet 5 (passing through the air trap 5a, if present).
During the cooking process, grease can fall from the overlying foodstuff to the bottom 3 of the cooking chamber 2, and it is collected into the cooking chamber outlet 4 and taken to the grease conduit 6, from which it is collected into the grease container 60.
Having provided two separated cooking chamber outlets, one dedicated to collect grease, reduces the possibility that grease could obstruct the second cooking chamber outlet 10 taking to the vapour outlet duct 9.
In the advantageous embodiment in which the bottom wall 3 of the cooking chamber 2 has a region 3a at least partially funnel-shaped at least at or in proximity to the inlet border 4a of first cooking chamber outlet 4, grease collected on this region 3a is very effectively taken by gravity into the first cooking chamber outlet 4.
In the still more preferred embodiment in which the inlet border 10a of the second cooking chamber outlet 10 is placed at a raised position with respect to the inlet border 4a of the first cooking chamber outlet 4, if the grease collects in the bottom wall 3 of the cooking chamber, it enters firstly the first cooking chamber 4, and it is therefore drained to the grease conduit 6 before reaching the level of the inlet border of the second cooking chamber outlet 10.
In the advantageous embodiment, illustrated for example in figure 8, in which the cooking oven 1 comprises a shield element 300 for preventing grease from entering the second cooking chamber outlet 10, such a shield element 300 prevents also grease drops falling from the foodstuff being cooked to directly enter the second cooking chamber outlet 10.
After the end of cooking process, the oven can be cleaned by the cleaning system 70; a cleaning procedure or method can be advantageously activated by the electronic controller 600, which operates on the electrically/electronically operated components of the cleaning system 70.
A schematic flow chart of a possible cleaning procedure or method is illustrated in figure 12.
The cleaning method advantageously starts with a washing phase 1000, in which, in the embodiment of figure 2, preferably after having emptied the cooking chamber 2 and having positioned a detergent, for example in form of a tablet or of powder, in the bottom 3 of the cooking chamber, the door 2a can be closed, and, with the second valve 12 and the first valve 11 closed, third valve 16b can be opened (preferably automatically by the electronic controller 600).
Once the liquid level or the liquid amount within the cooking chamber 2 has reached a prefixed washing value, third valve 16b can be closed (advantageously automatically by the electronic controller 600).
The liquid level within the cooking chamber 2 can be preferably detected, for example by a suitable level sensor, not illustrated, present within the cooking chamber 2.
The amount of liquid within the cooking chamber 2 can be detected for example by a flowmeter, not illustrated measuring the amount of water entering through the third valve 16b, and communicating this amount to the electronic controller 600.
Advantageously, the flowmeter can be used also for detecting the liquid level within the cooking chamber 2, since the liquid level and the liquid amount within the cooking chamber are correlated; in this case, the data detected by the flowmeter can be advantageously transmitted to the electronic controller 600, which can be advantageously configured for calculating the liquid level from the amount of liquid entering through the third valve 16b. In a further advantageous embodiment, the amount or the level of liquid within the cooking chamber can be controlled, preferably by the electronic controller 600, by keeping the third valve 16b opened for a prefixed time
Then, the circulation pump 7a is operated, so as to circulate the washing liquid (i.e. water mixed with the detergent present in the cooking chamber 2) through the circulation system 7. In particular, the washing liquid is circulated through the first cooking chamber outlet 4, grease conduit 6, connection duct 50, drain conduit 5b, second cooking chamber outlet 10, bottom region 9a and at least part of the end region 9b of the vapour outlet duct 9, by-pass conduit 14, aspiration duct 7b, delivery duct 7c, circulation outlet 13, cooking chamber 2. Washing liquid is taken by the pump 7a to the delivery duct 7c and, from the latter, to the vapour outlet duct cleaning pipe 450, from which it is emitted within the vapour outlet duct 9 in the form of a flow of cleaning liquid 451 (shown for example in figure 10) generating a swirl of cleaning liquid 452 flowing on the internal surface 90.
The swirl of cleaning liquid 452 advantageously flows on the internal surface 90 along the end region 9b of the vapour outlet duct 9, until reaching the bottom region 9a of the latter, from which it goes again to the circulation pump 7a via the by-pass conduit 14.
The cleaning of the cooking chamber 2 and of the vapour outlet duct 9 are therefore performed contemporaneously, which reduces the overall time required for the cleaning process.
Preferably, during the washing phase 1000, more preferably after all the washing liquid is loaded into the cooking chamber, and after switching on the circulation pump 7a, the heating device 8 is operated, so as to improve the degreasing effect of the washing liquid. More preferably the heating device 8 is operated for keeping the temperature within the cooking chamber at a prefixed temperature (e.g. 140°C), or within a range of temperatures (e.g. 120-160°C), to which corresponds a temperature of the water comprised between 70-80°C. Preferably, during the washing phase 1000, more preferably during activation of circulation pump 7a, the fan 20 is operated, so as to distribute the washing liquid falling from the circulation outlet 13 on all the surfaces internal to the cooking chamber 2.
It is underlined that, since the washing liquid flows swirling on the internal surface 90 of the vapour outlet duct 9, such liquid tends to adhere to such internal surface 90, and therefore it is quite unluckily that it can be dragged out of the vapour outlet duct 9 by airflow flowing in the vapour outlet duct 9.
Advantageously, the vortex preventing device 100 prevents the formation of air bubble that could prevent circulation pump 7a from properly priming.
At the end of the washing phase 1000 (e.g. after a certain time, counted for example by the electronic controller 600 has elapsed from the beginning of this phase), circulation pump 7a is stopped, and the second valve 12 is opened (preferably automatically by the electronic controller 600), so as to drain the washing liquid, advantageously by gravity, through the oven outlet 5.
Preferably, but not necessarily, during the washing phase 1000, after a certain time has lapsed from the switching on of the circulation pump 7a, a further amount of water can be loaded into the cooking chamber 2 by opening the third valve 16b, for example for a certain time, or until the quantity of water flown through the introduction conduit 16a, measured by a flowmeter (if provided), has reached a prefixed threshold, or until the liquid level within the cooking chamber 2 reaches a prefixed level. This further amount of water can be loaded while the circulation pump 7a is working, or the circulation pump 7a can be switched off during the further water loading.
Advantageously the washing liquid can be heated again during and/or after the loading of the further amount of water, by activating the heating device 8.
The cleaning method can advantageously comprise one or more rinsing phases 2000, 2001 in which, after closing the second valve 12 (which can be done automatically by the electronic controller 600), third valve 16b is opened again (preferably automatically by the electronic controller 600), so as to take rinsing liquid (i.e. water or water mixed with a rinsing liquid) within the cooking chamber 2.
Once the rinsing liquid level or the amount within the cooking chamber 2 has reached a prefixed rinsing value, third valve 16b can be closed (advantageously automatically by the electronic controller 600).
The liquid level within the cooking chamber 2 can be preferably detected, for example by a suitable level sensor, not illustrated, present within the cooking chamber 2.
The amount of liquid within the cooking chamber 2 can be detected for example by a flowmeter, not illustrated measuring the amount of water entering through the third valve 16b, and communicating this amount to the electronic controller 600.
Advantageously, the flowmeter can be used also for detecting the liquid level within the cooking chamber 2, since the liquid level and the liquid amount within the cooking chamber are correlated; in this case, the data detected by the flowmeter can be advantageously transmitted to the electronic controller 600, which can be advantageously configured for calculating the liquid level from the amount of liquid entering through the third valve 16b. In a further advantageous embodiment, the amount or the level of liquid within the cooking chamber can be controlled, preferably by the electronic controller 600, by keeping the third valve 16b opened for a prefixed time.
Then, preferably, circulation pump 7a is operated, so as to circulate the rinsing liquid through the circulation system 7, and to remove residuals of detergent possibly remained therein.
In particular, the rinsing liquid is circulated through the first cooking chamber outlet 4, grease conduit 6, connection duct 50, drain conduit 5b, second cooking chamber outlet 10, bottom region 9a and at least part of the end region 9b of the vapour outlet duct 9, by-pass conduit 14, aspiration duct 7b, delivery duct 7c, circulation outlet 13, cooking chamber 2. Rinsing liquid is taken by the pump 7a to the delivery duct 7c and, from the latter, to the vapour outlet duct cleaning pipe 450, from which it is emitted within the vapour outlet duct 9 in the form of a flow of cleaning liquid 451 (shown for example in figure 10) generating a swirl of cleaning liquid 452 flowing on the internal surface 90.
The swirl of cleaning liquid 452 flows on the internal surface 90, preferably along the end region 9b of the vapour outlet duct 9, until reaching the bottom region 9a of the latter, from which it goes again to the circulation pump 7a via the by-pass conduit 14.
The rinsing of the cooking chamber 2 and of the vapour outlet duct 9 are therefore performed contemporaneously, which reduces the overall time required for the cleaning process.
Once a rinsing phase 2000, 2001 is completed (e.g. after a certain time, counted for example by the electronic controller 600 has elapsed from the beginning of this phase), circulation pump 7a is stopped, and the second valve 12 is opened (preferably automatically by the electronic controller 600), so as to drain the rinsing water, advantageously by gravity, through the oven outlet 5.
One or more further rinsing phases, equal or substantially equal to the one just described, can be performed.
Preferably, during the rinsing phases 2000, 2001 the fan 20 is activated, so as to better distribute the rinsing liquid/clean water on all the surfaces internal to the cooking chamber 2.
It is underlined that, since the rinsing liquid flows swirling on the internal surface 90 of the vapour outlet duct 9, such liquid tends to adhere to such internal surface 90, and therefore it is quite unluckily that it can be dragged out of the vapour outlet duct 9 by airflow flowing in the vapour outlet duct 9.
Advantageously, before the last rinsing phase 2001, a descaling phase 3000 can be performed, which, in the embodiment of Figure 2, is advantageously almost equal to a rinsing phase 2000, 2001, with the difference that during the descaling phase 3000 a descaling additive, for example a descaling powder or tab, can be loaded (e.g. manually) into the cooking chamber 2, so as to generate a descaling liquid (i.e. water and descaling additive), which is circulated by the circulation system 7, so as to descale the surfaces that it contacts.
Preferably, the cleaning method can comprise, before the washing phase 1000, a soaking phase 4000; preferably, in the soaking phase 4000, with the second valve 12 and the first valve 11 closed, third valve 16b can be opened (preferably automatically by the electronic controller 600), preferably until a prefixed water level or amount is reached within the cooking chamber 2, and/or a prefixed time has lapsed until the third valve 16b has been opened. In the soaking phase 4000, heating device 8 is preferably switched on, so as to heat the water collected in the bottom 3 of the cooking chamber 2; then, after a certain time has lapsed, the second valve 12 is opened, and soaking water is drained via the oven drain 5. Then the washing phase 1000 can be performed.
With reference to the embodiment of figure 3, the functioning of the cooking oven according to the invention is the following.
Once the foodstuff has been loaded into the cooking chamber 2, and the door 2a closed, the cooking process can be started; the heating device 8 and the fan 20 are operated, advantageously by the electronic controller 600 of the cooking oven 1, according to a specific cooking program selected and/or programmed by a user.
Also ventilation valve 22 is controlled, advantageously by the electronic controller 600 of the cooking oven 1, for keeping fresh air from the external environment into the cooking chamber 2, advantageously according to the specific cooking program selected and/or programmed by the user.
During the cooking process, the steam supply system 35 can be operated, preferably by the electronic controller 600, according to the specific cooking program selected and/or programmed by a user, in order to take a prefixed steam amount into the cooking chamber 2. In particular, after water is loaded into the water reservoir 37 via the seventh valve 41, water heater 38 can be operated in order to heat such water and generate steam, which is taken into the cooking chamber 2 via the steam duct 43.
During the cooking process, the vapour present in the cooking chamber 2, the steam supplied by the steam supply system 35 (if present) and the high internal temperature, increase the internal pressure, and, when the latter exceeds ambient pressure, vapour is expelled to external of the cooking chamber 2 via the second cooking chamber outlet 10 and the vapour outlet duct 9.
It is underlined that the portion 453 of the vapour outlet duct cleaning pipe 450, being tangent to the internal surface 90 of the vapour outlet duct 9, does not substantially affect, or only marginally affects the flow of vapour through vapour outlet duct 9.
The quenching system 17, if provided, emits a jet of preferably fresh clean water, taken more preferably from external water mains, against the flow of vapour 400 flowing through the vapour outlet duct 9, cooling down and dehumidifying such a vapour; condensate resulting from this quenching process is collected in the bottom region 9a of the vapour outlet duct 9, and, preferably due to its slope, it is taken by gravity to the by-pass conduit 14, from which it is taken, still by gravity, to the drain conduit 5b, and to the oven outlet 5, from where it can be drained to the sewage pipes, not illustrated, of the building in which the cooking oven 1 is installed.
Advantageously, before reaching the oven outlet 5, the condensate reaches the air trap 5a (if provided), activating the latter (if not already activated by liquid present from previous usages of the cooking oven), so that vapour can't exit through it.
If condensate level within the vapour outlet duct 9 exceeds the level of the overflow conduit 26, it is drained by the latter directly to the oven outlet 5 (passing through the air trap 5a, if present).
During the cooking process, grease can fall from the overlying foodstuff to the bottom 3 of the cooking chamber 2, and it is collected into the cooking chamber outlet 4 and taken to the grease conduit 6, from which it is collected into the grease container 60.
Having provided two separated cooking chamber outlets, one dedicated to collect grease, reduces the possibility that grease could obstruct the second cooking chamber outlet 10 taking to the vapour outlet duct 9.
In the advantageous embodiment in which the bottom wall 3 of the cooking chamber 2 has a region 3a at least partially funnel-shaped at least at or in proximity to the inlet border 4a of first cooking chamber outlet 4, grease collected on this region 3a is very effectively taken by gravity into the first cooking chamber outlet 4.
In the still more preferred embodiment in which the inlet border 10a of the second cooking chamber outlet 10 is placed at a raised position with respect to the inlet border 4a of the first cooking chamber outlet 4, if the grease collects in the bottom wall 3 of the cooking chamber, it enters firstly the first cooking chamber 4, and it is therefore drained to the grease conduit 6 before reaching the level of the second cooking chamber outlet 10.
In the advantageous embodiment, illustrated for example in figure 8, in which the cooking oven 1 comprises a shield element 300 for preventing grease from entering the second cooking chamber outlet 10, such a shield element 300 prevents also grease droplets falling from the foodstuff being cooked to directly enter the second cooking chamber outlet 10. After the cooking process, the oven can be cleaned by the cleaning system 70; a cleaning method can be advantageously activated by the electronic controller 600, which operates on the electrically/electronically operated components of the cleaning system 70.
Schematic flow chart illustrated in figure 13 illustrates the phases of a possible cleaning method applied to the layout of figure 3.
The cleaning method advantageously comprises a steam supply system descaling phase 5000, in which the water reservoir 37 of the steam supply system 35 is preferably emptied by opening the eight valve 42, and a descaling additive is loaded in the additive drawer 28. Then, with seventh valve 41, eight valve 42, and sixth valve 30 closed, the fifth valve 29 is opened (preferably automatically by the electronic controller 600), so that clean water enters the additive drawer 28, dissolves, preferably only partially, the descaling additive contained therein, forming a descaling solution (i.e. water and descaling additive) which is taken, due to the pressure of the water in the water mains, into the water reservoir 37 through the boiler cleaning duct 44.
Preferably, the water reservoir is only partially filled with the descaling solution coming from the drawer 28, since a part of the descaling additive should preferably remain in the additive drawer for being used in a further step of the automatic or semi-automatic cleaning method.
Advantageously the amount of water loaded into the water reservoir is controlled by a flowmeter, not illustrated, provided at or in series with the fifth valve 29, and preferably controlled by the electronic controller 600 in such a way to close the valve after a prefixed amount of water has flown into the additive drawer 28.
The electronic controller 600 is also preferably configured in such a way that, in addition or in alternative to the flowmeter, a time-based control of the opening of the fifth valve 29 is performed; in other words, the valve is closed after a certain prefixed time has lapsed until its opening.
More preferably, some further water is loaded into the water reservoir 37 by opening (preferably automatically by the electronic controller 600) the seventh valve 41, until a prefixed level within the reservoir 37 is reached, and/or a prefixed time has lapsed until the opening of such seventh valve 41. In this way a prefixed concentration of descaling additive in the descaling solution contained in the water reservoir is obtained. Then the seventh valve 41 is closed.
Advantageously, the water heater 38 is switched on (preferably automatically by the electronic controller 600), so as to increase the descaling effect.
Preferably, the water heater 38 is controlled, preferably by the electronic controller 600, in order to keep a prefixed temperature within the reservoir 37, for example 80°C; preferably the temperature is measured by a temperature sensor, not illustrated, provided in the water reservoir 37.
Preferably, the descaling solution is kept into the water reservoir 37 for a prefixed time, more preferably one hour and a half. Preferably, this time can be regulated by the user, for example operating on a user interface of the cooking oven 1.
The method for cleaning a cooking oven according to the advantageous embodiment of figure 3, advantageously comprises also a washing phase 1000 in which, preferably after having emptied the cooking chamber 2 a detergent, for example in form of a tablet or of powder, is placed in the bottom 3 of the cooking chamber, and the door 2a can be closed.
It is underlined that the steam supply system descaling phase 5000 and the washing phase 1000 can start contemporaneously, or one can start before the other.
Advantageously, in the washing phase 1000, preferably while the water reservoir 37 is being descaled, or before or after this phase, with the second valve 12 and the first valve 11 closed, third valve 16b can be opened (preferably automatically by the electronic controller 600).
The liquid level or amount within the cooking chamber 2 is preferably detected, for example by a suitable level sensor, not illustrated, present within the cooking chamber 2, and/or by a flowmeter, not illustrated measuring the amount of water entering through the third valve 16b, and communicating this amount to the electronic controller 600, which is configured for calculating the liquid level from the amount of liquid entering through the third valve 16b.
Once the liquid level or amount within the cooking chamber 2 has reached a prefixed value, and/or after a certain time has lapsed, third valve 16b is closed (advantageously automatically by the electronic controller 600).
The, circulation pump 7a is operated, so as to circulate the washing liquid (i.e. water mixed with the detergent present in the cooking chamber 2) through the circulation system 7.
In particular, the washing liquid is circulated through the first cooking chamber outlet 4, grease conduit 6, connection duct 50, drain conduit 5b, second cooking chamber outlet 10, bottom region 9a and at least part of the end region 9b of the vapour outlet duct 9, by-pass conduit 14, aspiration duct 7b, delivery duct 7c, circulation outlet 13, cooking chamber 2. Washing liquid is taken by the pump 7a to the delivery duct 7c and, from the latter, to the vapour outlet duct cleaning pipe 450, from which it is emitted within the vapour outlet duct 9 in the form of a flow of cleaning liquid 451 (shown for example in figure 10) generating a swirl of cleaning liquid 452 flowing on the internal surface 90.
The swirl of cleaning liquid 452 flows on the internal surface 90 along the end region 9b of the vapour outlet duct 9, until reaching the bottom region 9a of the latter, from which it goes again to the circulation pump 7a via the by-pass conduit 14.
The cleaning of the cooking chamber 2 and of the vapour outlet duct 9 are therefore performed contemporaneously, which reduces the overall time required for the cleaning process.
Preferably, during the washing phase 1000, more preferably after all the washing liquid is loaded into the cooking chamber 2, and after switching on the circulation pump 7a, the heating device 8 is operated, so as to improve the degreasing effect of the washing liquid. More preferably the heating device 8 is operated for keeping the temperature within the cooking chamber at a prefixed temperature (e.g. 140°C), or within a range of temperatures (e.g. 120-160°C), to which corresponds a temperature of the water comprised between 70-80°C.
Preferably, during the washing phase 1000, more preferably while the circulation pump 7a is operated, the fan 20 is operated, so as to distribute the washing liquid falling from the circulation outlet 13 on all the surfaces internal to the cooking chamber 2.
It is underlined that, since the washing liquid flows swirling on the internal surface 90 of the vapour outlet duct 9, such liquid tends to adhere to such internal surface 90, and therefore it is quite unluckily that it can be dragged out of the vapour outlet duct 9 by airflow flowing in the vapour outlet duct 9.
Advantageously, the vortex preventing device 100 prevents the formation of air bubble that could prevent circulation pump 7a from properly priming.
At the end of the washing phase 1000 (e.g. after a certain time, counted for example by the electronic controller 600 has elapsed from the beginning of this phase), circulation pump 7a is stopped, and the second valve 12 is opened (preferably automatically by the electronic controller 600), so as to drain the washing liquid, advantageously by gravity, through the oven outlet 5.
Preferably, but not necessarily, during the washing phase 1000, after a certain time has lapsed from the switching on of the circulation pump 7a, a further amount of water can be loaded into the cooking chamber 2 by opening the third valve 16b, for example for a certain time, or until the quantity of water flown through the introduction conduit 16a, measured by a flowmeter (if provided), or until the water level within the cooking chamber 2, has reached a prefixed value. This further amount of water can be loaded while the circulation pump 7a is working, or the circulation pump 7a can be switched off during the further water loading. Advantageously the washing liquid can be heated again during and/or after the loading of the further amount of water, by activating the heating device 8.
The cleaning method advantageously comprises a rinsing phase 2000 in which, after closing the second valve 12 (which can be done automatically by the electronic controller 600), third valve 16b is opened again (preferably automatically by the electronic controller 600), so as to take clean rinsing liquid within the cooking chamber 2.
Once the rinsing liquid level or amount within the cooking chamber 2 has reached a prefixed value, third valve 16b can be closed (advantageously automatically by the electronic controller 600).
The liquid level within the cooking chamber 2 can be preferably detected, for example by a suitable level sensor, not illustrated, present within the cooking chamber 2.
The amount of liquid within the cooking chamber 2 can be detected for example by a flowmeter, not illustrated measuring the amount of water entering through the third valve 16b, and communicating this amount to the electronic controller 600.
Advantageously, the flowmeter can be used also for detecting the liquid level within the cooking chamber 2, since the liquid level and the liquid amount within the cooking chamber are correlated; in this case, the data detected by the flowmeter can be advantageously transmitted to the electronic controller 600, which can be advantageously configured for calculating the liquid level from the amount of liquid entering through the third valve 16b. In a further advantageous embodiment, the amount or the level of liquid within the cooking chamber can be controlled, preferably by the electronic controller 600, by keeping the third valve 16b opened for a prefixed time.
Then, preferably, circulation pump 7a is operated, so as to circulate the rinsing liquid through the circulation system 7, and to remove residuals of detergent possibly remained therein.
In particular, the rinsing liquid is circulated through the first cooking chamber outlet 4, grease conduit 6, connection duct 50, drain conduit 5b, second cooking chamber outlet 10, bottom region 9a and at least part of the end region 9b of the vapour outlet duct 9, by-pass conduit 14, aspiration duct 7b, delivery duct 7c, circulation outlet 13, cooking chamber 2. Rinsing liquid is taken by the pump 7a to the delivery duct 7c and, from the latter, to the vapour outlet duct cleaning pipe 450, from which it is emitted within the vapour outlet duct 9 in the form of a flow of cleaning liquid 451 (shown for example in figure 10) generating a swirl of cleaning liquid 452 flowing on the internal surface 90.
The swirl of cleaning liquid 452 flows on the internal surface 90 along the end region 9b of the vapour outlet duct 9, until reaching the bottom region 9a of the latter, from which it goes again to the circulation pump 7a via the by-pass conduit 14.
The rinsing of the cooking chamber 2 and of the vapour outlet duct 9 are therefore performed contemporaneously, which reduces the overall time required for the cleaning process.
At the end of the rinsing phase 2000 (e.g. after a certain time, counted for example by the electronic controller 600 has elapsed from the beginning of this phase), circulation pump 7a is stopped, and the second valve 12 is opened (preferably automatically by the electronic controller 600), so as to drain the rinsing liquid, advantageously by gravity, through the oven outlet 5.
Preferably, during the rinsing phases 2000, 2001 the fan 20 is activated, so as to better distribute the rinsing liquid on all the surfaces internal to the cooking chamber 2.
It is underlined that, since the rinsing liquid flows swirling on the internal surface 90 of the vapour outlet duct 9, such liquid tends to adhere to such internal surface 90, and therefore it is quite unluckily that it can be dragged out of the vapour outlet duct 9 by airflow flowing in the vapour outlet duct 9.
One or more further rinsing phases 2001, equal or substantially equal to the one just described, can be performed.
After one or more rinsing phases, a descaling phase 3000 can be advantageously performed.
When the method according to the invention is advantageously applied to the embodiment of the oven figure 3, preferably, in the descaling phase 3000, with first valve 11 and second valve 12 closed, and sixth valve 30 opened, fifth valve 29 is opened (preferably automatically by the electronic controller 600), so that clean water enters the additive drawer 28, dissolves, preferably completely, the descaling additive contained therein, forming a descaling liquid (i.e. water and descaling additive), and goes by gravity through sixth valve 30, to the aspiration conduit 7b.
Advantageously the amount of water loaded into the water reservoir is controlled by a flowmeter, not illustrated, provided at or in series with the fifth valve 29, and preferably controlled by the electronic controller 600 in such a way to close the valve after a prefixed amount of water has flown into the additive drawer 28.
The electronic controller 600 is also preferably configured in such a way that, in addition or in alternative to the flowmeter, a time-based control of the opening of the fifth valve 29 is performed; in other words, the valve is closed after a certain prefixed time has lapsed until its opening.
In the descaling phase 3000, circulation pump 7a is advantageously operated, so as to circulate the descaling liquid (i.e. water mixed with the descaling additive present in the additive drawer 28) through the circulation system 7.
In particular, the descaling liquid is circulated through the first cooking chamber outlet 4, grease conduit 6, connection duct 50, drain conduit 5b, second cooking chamber outlet 10, bottom region 9a and at least part of the end region 9b of the vapour outlet duct 9, by-pass conduit 14, aspiration duct 7b, delivery duct 7c, circulation outlet 13, cooking chamber 2. Descaling liquid is taken by the pump 7a to the delivery duct 7c and, from the latter, to the vapour outlet duct cleaning pipe 450, from which it is emitted within the vapour outlet duct 9 in the form of a flow of cleaning liquid 451 (shown for example in figure 10) generating a swirl of cleaning liquid 452 flowing on the internal surface 90.
The swirl of cleaning liquid 452 flows on the internal surface 90 along the end region 9b of the vapour outlet duct 9, until reaching the bottom region 9a of the latter, from which it goes again to the circulation pump 7a via the by-pass conduit 14.
The descaling of the cooking chamber 2 and of the vapour outlet duct 9 are therefore performed contemporaneously, which reduces the overall time required for the cleaning process.
Preferably, during the descaling phase 3000, the heating device 8 is operated, so as to improve the descaling effect of the descaling liquid.
Preferably, during the descaling phase 3000, the fan 20 is operated, so as to distribute the descaling liquid falling from the circulation outlet 13 on all the surfaces internal to the cooking chamber 2.
It is underlined that, since the descaling liquid flows swirling on the internal surface 90 of the vapour outlet duct 9, such liquid tends to adhere to such internal surface 90, and therefore it is quite unluckily that it can be dragged out of the vapour outlet duct 9 by airflow flowing in the vapour outlet duct 9.
At the end of the descaling phase 3000 (e.g. after a certain time, counted for example by the electronic controller 600 has elapsed from the beginning of this phase), circulation pump 7a is stopped, and the second valve 12 is opened (preferably automatically by the electronic controller 600), so as to drain the descaling liquid, advantageously by gravity, through the oven outlet 5.
Preferably, but not necessarily, at the same time with the completion of the descaling phase 3000, the steam supply system descaling phase 5000 can be completed; in this case, preferably automatically by the electronic controller 600, water heater 38 is switched off, eight valve 42 is opened, and the descaling solution present in the water reservoir 37 drained, advantageously by gravity, through the oven outlet 5.
Finally, a further rinsing phase 2001, equal to the ones described above, can be performed, so as to remove possible residuals of descaling solution from the internal of the oven.
In addition, cleaning method preferably comprises a steam supply system rinsing phase 6000, comprising closing the eight valve 42 and opening the seventh valve 41 for a prefixed time, and/or until a prefixed water level is reached within the water reservoir, so as to load clean water within the water reservoir 37, and finally, after a prefixed time has lapsed , opening the eight valve 42, so as to drain, by gravity, rinsing water via the oven outlet 5. Preferably, the cleaning method can comprise, before the washing phase 1000, a soaking phase 4000; preferably, in the soaking phase 4000, with the second valve 12 and the first valve 11 closed, third valve 16b can be opened (preferably automatically by the electronic controller 600), preferably until a prefixed water level or amount is reached within the cooking chamber 2, and/or a prefixed time has lapsed until the third valve 16b has been opened. In the soaking phase 4000, heating device 8 is switched on, so as to heat the water collected in the bottom 3 of the cooking chamber 2; then, after a certain time has lapsed, the second valve 12 is opened, and soaking water is drained via the oven drain 5. Then the washing phase 1000 can be performed.
The cleaning method of the advantageous embodiment of the oven illustrated in figure 4, advantageously differs from the method described with reference to the oven of figure 3 only because:

during the washing phase 1000 of the cleaning method, the detergent is not placed in the bottom 3 of the cooking chamber by the user, but it is taken directly into the introduction system 16, preferably into the introduction conduit 16a, by operating additive pump 34b, in such a way to pump the washing additive out of the additive container 32b and pump the washing additive in the introduction system 16;
during the steam supply system descaling phase 5000, and during the descaling phase 3000, preferably, the descaling additive is not manually loaded into the additive drawer 28, but it is loaded into the additive drawer by operating additive pump 34a, in such a way to pump the descaling additive out of the additive container 32a and to pump the descaling additive in the additive drawer 28.

In the method according to the invention, when applied to a cooking oven according to the advantageous embodiment of figure 4, the amount of descaling additive supplied to the additive drawer 28 can be advantageously controlled by operating the additive pump 34a for a prefixed time, and/or by measuring the amount of liquid flowing through additive delivery conduit 33a, for example by a flowmeter, not illustrated.
In the advantageous embodiment of figure 4, the amount of washing agent supplied to the introduction system 16 is controlled by operating the additive pump 34b for a prefixed time, and/or by measuring the amount of liquid flowing through additive delivery conduit 33b, for example by a flowmeter, not illustrated.
It is underlined that in the embodiment of figure 4, an additive can be loaded also manually into the additive drawer 28 (for example if the additive container 32a is empty, and/or for adding a further kind of additive in addition to the one contained in additive container 32a). The cleaning method of the advantageous embodiment of the oven illustrated in figure 5, advantageously differs from the method described with reference to the oven of figure 1 only because:

during the washing phase 1000 of the cleaning method, the detergent is not placed in the bottom 3 of the cooking chamber by the user, but it is taken directly into the introduction system 16, preferably into the introduction conduit 16a, by operating additive pump 34b, in such a way to pump the washing additive out of the additive container 32b and pump the washing additive in the introduction system 16, from which it is taken, together with the water entering the third valve 16b, into the cooking chamber 2;
during the descaling phase 3000, the descaling additive is not manually loaded into the cooking chamber 2, but it is loaded into the introduction system by operating additive pump 34a, in such a way to pump the descaling additive out of the additive container 32a and to pump the washing additive in the introduction system 16, from which it is taken, together with the water entering the third valve 16b, into the cooking chamber 2.

In the advantageous embodiment of figure 5, during the cleaning method, the amount of descaling additive supplied to introduction system 16 can be advantageously controlled by operating the additive pump 34a for a prefixed time, and/or by measuring the amount of liquid flowing through additive delivery conduit 33a, for example by a flowmeter, not illustrated.
In the advantageous embodiment of figure 5, during the cleaning method, the amount of washing agent supplied to the introduction system 16 is controlled by operating the additive pump 34b for a prefixed time, and/or by measuring the amount of liquid flowing through additive delivery conduit 33b, for example by a flowmeter, not illustrated.
The cleaning method of the advantageous embodiment of the oven illustrated in figure 6, preferably differs from the embodiment of the method described with reference to the oven of figure 1 because:

during the washing phase 1000 of the cleaning method, the detergent is not placed in the bottom 3 of the cooking chamber by the user, but it is taken directly into the introduction system 16, preferably into the introduction conduit 16a, by operating additive pump 34b, in such a way to pump the washing additive out of the additive container 32b and pump the washing additive in the introduction system 16, from which it is taken, together with the water entering the third valve 16b, into the cooking chamber 2;
during the descaling phase 3000, preferably, the descaling additive is not manually loaded into the cooking chamber 2, but is loaded into the additive drawer 28 by operating additive pump 34a, in such a way to pump the descaling additive out of the additive container 32a and to pump the descaling additive in the additive drawer 28.

In the advantageous embodiment of figure 6, during the cleaning method, the amount of descaling additive supplied to the additive drawer 28 can be advantageously controlled by operating the additive pump 34a for a prefixed time, and/or by measuring the amount of liquid flowing through additive delivery conduit 33a, for example by a flowmeter, not illustrated.
In the advantageous embodiment of figure 6, during the cleaning method, the amount of washing agent supplied to the introduction system 16 is controlled by operating the additive pump 34b for a prefixed time, and/or by measuring the amount of liquid flowing through additive delivery conduit 33b, for example by a flowmeter, not illustrated.
It is underlined that in the advantageous embodiment of figure 6 it is possible loading also manually an additive into the additive drawer 28 (for example if the additive container 32a is empty, and/or for adding a further kind of additive in addition to the one contained in additive container 32a).
It is also highlighted that, in the advantageous embodiment of figure 6, it is also possible taking an additive from the additive container 32a directly into the vapour outlet duct 9 without operating the circulation pump 7a; in fact, with the fifth valve 29 and the sixth valve 30 closed, by operating the additive pump 34a, the liquid contained in the additive container 32a is delivered into the additive drawer 28, and from the latter to the further vapour outlet duct cleaning pipe 460, from which this liquid is emitted within the vapour outlet duct 9 in the form of a further flow of cleaning liquid 461 (shown for example in figure 11) generating a further swirl of cleaning liquid 462 flowing on the internal surface 90.
It is underlined that in a further advantageous embodiment, not illustrated, an additive delivery conduit 33a of the multi-dosing system 31 can be connected directly to the further vapour outlet duct cleaning pipe 460.
It is seen therefore how the invention achieves the proposed aim and objects, there being provided a cooking oven in which, thanks to the shape of the internal surface of the vapour outlet duct, and to the arrangement of the vapour outlet duct cleaning pipe, it is possible to generate a swirl of cleaning liquid flowing on the internal surface of the vapour outlet duct which effectively cleans the latter.
Since it is quite difficult that the swirl of cleaning liquid flowing on the internal surface of the vapour outlet duct is dragged out of the vapour outlet duct by airflow flowing in the duct, it is possible performing the cleaning of the cooking chamber (which is done preferably while operating the fan of the cooking oven) and the cleaning of the vapour outlet duct contemporaneously, with the effect of reducing the overall time required for cleaning the oven.
The position of the vapour outlet duct cleaning pipe, and in particular of its end portion at least partially tangent to the internal surface of the vapour outlet duct, favours the formation of the swirl on the internal surface, and has also a minimal disturbing effect on the flow of vapour during the cooking process.

Claims

Cooking oven (1) for foodstuffs comprising:
- a cooking chamber (2), wherein foodstuffs can be placed for being cooked,

- a vapour outlet duct (9) configured for discharging vapour from the cooking chamber (2) to the external of the cooking oven (1),

- a cleaning system (70) for cleaning the cooking oven (1), comprising a vapour outlet duct cleaning pipe (450) configured for taking a cleaning liquid within said vapour outlet duct (9),
characterized in that
said vapour outlet duct (9) comprises an internal surface (90) having a circular, or substantially circular, or oval, or substantially oval, cross section,
and in that
said vapour outlet duct cleaning pipe (450) is configured for emitting within said vapour outlet duct (9) a flow of cleaning liquid (451) generating a swirl of cleaning liquid (452) flowing on said internal surface (90).
Cooking oven (1), according to claim 1, wherein said vapour outlet duct cleaning pipe (450) is configured for emitting within said vapour outlet duct (9) said flow of cleaning liquid (451) tangent or substantially tangent to said internal surface (90) of said vapour outlet duct (9).
Cooking oven (1), according to claim 1 or 2, wherein said vapour outlet duct cleaning pipe (450) is positioned partially outside said vapour outlet duct (9), and comprises an end portion (453) positioned within said vapour outlet duct (9), and at least partially tangent to the internal surface (90) of the latter, so that the flow of cleaning liquid (451) exiting said end portion (453) is tangent or substantially tangent to said internal surface (90).
Cooking oven (1), according to claim 3, wherein said end portion (453) is inclined downwards with respect to an operative position of said cooking oven (1), so that a flow of cleaning liquid (451) is directed downwards as it exits said end portion (453).
Cooking oven (1), according to one or more of the previous claims, wherein said cleaning system (70) comprises a circulation system (7) configured for pumping liquid out of said cooking chamber (2) and for pumping such liquid, or a part thereof, again in said cooking chamber (2), wherein said vapour outlet duct cleaning pipe (450) is fluidly connected to said circulation system (7) and is arranged for taking a liquid flowing through the latter into said vapour outlet duct (9).
Cooking oven (1), according to claim 5, wherein said circulation system (7) comprises a circulation pump (7a), an aspiration conduit (7b) connecting said circulation pump (7a) to a cooking chamber outlet (4, 10) provided in said cooking chamber (2), and a delivery conduit (7c) connecting said circulation pump (7a) to a washing/rinsing liquid circulation outlet (13) provided in said cooking chamber (2) and configured for allowing washing/rinsing liquid to enter said cooking chamber (2), wherein said vapour outlet duct cleaning pipe (450) is fluidly connected to said delivery conduit (7c), so as to take at least a part of washing/rinsing liquid flowing into the latter into said vapour outlet duct (9).
Cooking oven (1), according to claim 6, wherein said circulation system (7) is configured for delivering a washing/rinsing liquid in parallel to said vapour outlet duct cleaning pipe (450) and to said washing/rinsing liquid circulation outlet (13).
Cooking oven (1) according to one or more of the previous claims, wherein said vapour outlet duct (9) comprises:
- a bottom region (9a), positioned, in the operative position of the cooking oven (1), at least partially below said cooking chamber (2), and fluidly connected downstream of a cooking chamber outlet (4, 10) provided in said cooking chamber (2),

- an end region (9b) protruding upwards from said bottom region (9a), from which vapour is released to the external of said cooking oven (1),
wherein said internal surface (90) having a circular, or substantially circular, or oval, or substantially oval, cross section of said vapour outlet duct (9) is comprised in said end region (9b) of the latter.
Cooking oven (1) according to one or more of the previous claims, comprising a further outlet duct cleaning pipe (460) configured for emitting within said vapour outlet duct (9) a further flow of cleaning liquid (461) generating a further swirl of cleaning liquid (462) flowing on said internal surface (90).
Cooking oven (1), according to claim 9, wherein said further outlet duct cleaning pipe (460) is configured for emitting within said vapour outlet duct (9) said further flow of cleaning liquid (461) tangent or substantially tangent to said internal surface (90) of said vapour outlet duct (9).
Cooking oven (1), according to claim 9 or 10, wherein said further vapour outlet duct cleaning pipe (460) is positioned partially outside said vapour outlet duct (9), and comprises an end portion (463) positioned within said vapour outlet duct (9), and at least partially tangent to the internal surface (90) of the latter, so that the further flow of cleaning liquid (461) exiting said end portion (463) of said further vapour outlet duct cleaning pipe (460) is tangent or substantially tangent to said internal surface (90).
Cooking oven (1), according to claim 11, wherein said end portion (463) of said further vapour outlet duct cleaning pipe (460) is inclined downwards with respect to an operative position of said cooking oven (1), so that a further flow of cleaning liquid (461) is directed downwards as it exits said end portion (463).
Cooking oven (1), according to one or more of claims 9 to 12, wherein said further vapour outlet duct cleaning pipe (460) is fluidly connected to said circulation system (7) and is arranged for taking a liquid flowing through the latter into said vapour outlet duct (9).
Cooking oven (1), according to one or more of claims 9 to 13 comprising a washing/rinsing additive supplying system (27) configured for supplying washing and/or rinsing additives to the internal of said cooking chamber (2), wherein said further vapour outlet duct cleaning pipe (460) is fluidly connected to said washing/rinsing additive supplying system (27), so as to take a washing and/or rinsing additive contained therein to said vapour outlet duct (9).
Method for cleaning a cooking oven (1) according to one or more of claims 1 to 14, comprising the following steps:
- taking a cleaning liquid within said vapour outlet duct cleaning pipe (450);

- emitting a flow of said cleaning liquid (451) within said vapour outlet duct (9) via said vapour outlet duct cleaning pipe (450) in such a way to generate a swirl of cleaning liquid (452) flowing on said internal surface (90) of said vapour outlet duct (9) having a circular, or substantially circular, or oval, or substantially oval, cross section.