WO2017182660A1

WO2017182660A1 - Boiler

Info

Publication number: WO2017182660A1
Application number: PCT/EP2017/059568
Authority: WO
Inventors: Giuseppe De' Longhi; Antonio Lorenzon; Laura DURANTE; Riccardo GIROTTO
Original assignee: De' Longhi Appliances S.R.L. Con Unico Socio
Priority date: 2016-04-22
Filing date: 2017-04-21
Publication date: 2017-10-26
Also published as: EP3446044A1; RU2018138762A; RU2752395C2; CN109416196A; CN109416196B; RU2018138762A3; EP3446044B1

Abstract

Boiler for generating steam and/or for heating water, comprising a metal container (12) provided at least with a feed aperture (14) to introduce water inside it, and with a heating element (26).

Description

"BOILER"

FIELD OF THE INVENTION

The present invention concerns a boiler for generating steam and/or for heating water, usable in domestic appliances and professional machines such as, for example, ironing or cleaning apparatuses, coffee machines, steamers for cooking food, steam ovens and suchlike.

The invention also concerns a device for collecting limescale associated fixedly with the boiler to collect the limescale that forms inside the boiler during use.

BACKGROUND OF THE INVENTION

Boilers used to selectively generate steam and/or to heat water in domestic appliances and professional machines normally comprise a metal container, hermetically closed, provided with at least an entrance aperture for the water, and possibly with an exit aperture for the steam.

Some types of boiler can also comprise a discharge aperture to empty the water from the container, and to clean or inspect it.

A heating element is normally associated with the metal container, generally an electric resistance or plate, selectively activated to generate the desired quantity and/or quality of steam and/or to take the water to the desired temperature.

Boilers normally also comprise one or more detection devices to detect the temperature and/or pressure inside the metal container, so as to monitor them and/or control them depending on the desired value, and also to prevent them from exceeding determinate safety values.

It is known that, when the boiler is used and due to heating the water, formations of limescale are generated inside the metal container, consisting of calcium carbonate and/or other minerals such as magnesium, potassium and silicon, normally dissolved in the water.

These formations of limescale can remain in suspension or are deposited to form incrustations of increasing thickness on the internal walls of the metal container, thus influencing the functioning of both the means that generate the heat and also the detection devices. Indeed it is known that these formations of limescale that are deposited on the heat source, or around the zone where the heating element operates, reduce the effect of said heat source.

A reduced heat transmission and/or an incorrect, or delayed, detection of the temperature or pressure can lead on the one hand to a waste of energy, and on the other hand to the safety values being exceeded, and hence at least to damage to the boiler.

The formations of limescale in suspension in the water inside the container risk occluding the valve that conditions the exit of the steam from the container, if the boiler is provided for generating steam.

To try to at least partly solve these problems, it is known to provide one or more elements installed inside the container, removable from it, to promote the capture and subsequent removal of the limescale in suspension in the water.

These known elements are generally made of a removable metal rod, immersed in the water inside the boiler, or other similar or comparable solid elements, normally with an elongated and filiform structure and shape.

Examples of such known removable elements are described in documents WO 2008/075308, DE 10 201 1 086147, DE 10 2010 062939 and WO 2010/139599. It is also known to provide the use of a rod that defines one or a plurality of containing compartments where the particles of limescale in suspension in the water are deposited.

These known capturing elements do not guarantee an effective adherence and attachment of the limescale on or inside them, which in any case means that a high residual quantity of limescale remains inside the container, both in suspension in the water and also associated with the walls of the container and/or the source of heat.

Furthermore, as the level of water inside the boiler varies, the capturing element can be at least partly exposed by the water, which causes it to lose temperature and hence to have a reduced capacity of capturing the limescale.

One purpose of the present invention is to obtain a boiler to heat water, and possibly also to generate steam, that allows on the one hand to prevent energy waste and on the other hand to monitor constantly and effectively over time the physical quantities of interest, in particular the temperature and/or pressure, inside the metal container.

Another purpose is to obtain a boiler to generate steam that is simple, economical, reliable and long-lasting.

Another purpose is to obtain a boiler that promotes and maximizes in a circumscribed place the aggregation of limescale inside the container and that on the one hand prevents as much as possible the limescale from adhering to and depositing onto the internal wall of the container, and on the other hand that prevents particles of limescale from remaining in suspension in the water.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, the present invention concerns a boiler for generating steam and/or for heating water that comprises a metal container, hermetically closed and provided at least with a feed aperture to introduce water inside it.

The container is also defined by a lower wall, an upper wall, opposite the lower wall, and at least one lateral wall.

The container can also be provided with a possible aperture for cleaning and/or inspection, with a heating element and with at least a device to detect the physical quantities, such as, but not only, temperature, level and/or pressure. According to one aspect of the present invention, there is at least one collector device or aggregator to collect the limescale inside the container, which, during use, is partly immersed in the water.

According to another aspect of the present invention, the collector device, which may or may not comprise at least a frame, is attached, clamped, in contact with and/or pressed to at least an internal wall of the container, for example the upper, lower or lateral wall, and has a three-dimensional geometry that develops inside the container.

The collector device, staying fixed in a non-removable position inside the boiler, facilitates the accumulation of limescale around it, since the limescale tends to accumulate more easily onto other limescale, rather than on the metal walls of the container. In this way, the choice for the positioning of the detection devices is made easier, advantageously in areas not subjected to the accumulation of limescale.

According to another aspect of the present invention, the collector device has at least a metal filtering element, or with a ceramic based material, or similar materials, with a reticular, pleated or spiral structure to aggregate and retain the limescale.

According to one embodiment, the frame, if there is one, can define a containing compartment for the installation of the filtering element inside it.

The frame is preferably made of metal material, or of a heat-resistant plastic material, and is provided on its surface with through holes that allow the free passage of the water through it.

According to another embodiment, the frame and/or the filtering element are disposed at least partly in contact with the heating element, that is, the contact with one or more of the internal walls of the container is provided in a condition correlated to the position of the heating element.

The collector device, because of its position and structural conformation, has the function of facilitating the adherence of the limescale in the collector device, so as to keep the limescale compartmentalized in a specific area of the container, reducing the loose limescale in the water.

Moreover, should it ever be necessary to empty the container of the water contained inside it, and the possible loose limescale, a slight inclination of the container would not compromise the position of the collector device.

Moreover, the contact of a lower part, and/or an upper part, of the collector device with a lower and/or upper wall of the container, or with the heating element, keeps the temperature of the collector device high even when it is partly exposed by the hot water, which increases the capacity of the limescale to aggregate on the overall surface of the collector device. According to an advantageous embodiment, the collector device is disposed in contact, pressed and stably kept in position with both the lower wall and also with the upper wall of the container, and possibly also with the heating element, if this is positioned inside the container.

In this way, the contact of the collector device with the corresponding portions of the upper and lower walls, and possibly with the heating element, considerably promotes the formation and adherence of the limescale.

The invention also concerns the collector device with the characteristics identified above.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is a perspective view in vertical section of a boiler in one embodiment;

- fig. 2 is a view in section of the boiler in fig. 1 ;

- fig. 3 is a perspective view in vertical section of a boiler in another embodiment;

- fig. 4 is a view in section of the boiler in fig. 3;

- fig. 5 is a perspective view in vertical section of the boiler in another embodiment;

- fig. 6 is a perspective view in vertical section of the boiler in another embodiment;

- fig. 7 is a view in section of the boiler in fig. 6.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

Embodiments described here with reference to figs. 1-7 concern a boiler 10 for generating steam and/or for heating water, usable in domestic appliances and professional machines such as, for example, ironing or cleaning apparatuses, coffee machines, steamers for cooking food, steam ovens and suchlike.

The boiler 10 comprises a metal container 12, suitable to contain the water and possibly also to transform it into steam.

The container 12 is closed hermetically and is provided with a feed aperture 14 to introduce water inside it. According to some embodiments, the container 12 is made of a lower shell 12a and an upper shell 12b, hermetically sealed and/or welded to each other, so as to resist the possible pressure that is generated inside the container 12.

The container 12, that is, the lower 12a and upper shell 12b, is defined by a lower wall 13, an upper wall 15, opposite the lower wall 13, and at least a lateral wall 17.

The container 12 can also be provided with a steam exit aperture 16 connected to user devices and possible steam regulation devices, for example an electromechanical valve or suchlike.

Another aperture can be present that allows to clean and/or inspect inside the container 12, for example an exit hole 18.

The boiler 10 comprises a heating element 26 associated with the container 12, inside or outside it, and configured to heat the water inside it to take it to evaporation temperature, or the desired heating temperature.

In the case shown in the attached drawings, the heating element 26 consists of a wire resistance disposed below the lower wall 13 of the container 12. However, it comes within the framework of the present invention that the heating element 26 can be associated with the upper wall 15, with both walls 13, 15 or is also disposed, wholly or partly, inside the container 12.

Devices 32 to detect physical quantities are associated with the container 12, for example temperature, level or pressure, advantageously located outside or at least partly cooperating with the inside of the container 12.

According to one embodiment, shown by way of example in figs. 6 and 7, the detection device 32 can be a device 33 to detect the level of the water inside the container 12.

The device 33 to detect the level of the water can be installed on the lateral wall 17 of the container 12.

According to another embodiment shown by way of example in fig. 7, the detection device 32 can be a heat detector 34 installed in contact with the heating element 26.

According to the present invention, the boiler 10 comprises at least a limescale collector or aggregator device 20, located inside the container 12 and which during use is at least partly immersed in the water. The collector device 20 is disposed fixedly inside the container, and has at least one part in contact with one or more of the walls 13, 15 or 17 of the container 12, so that the heat of the walls is transmitted to the collector device 20 and thus increases its capacity to aggregate limescale.

According to another aspect of the present invention, shown by way of example in figs. 1-5, the collector device 20 comprises at least a frame 22 attached to at least one wall of the container 12 and having a three-dimensional geometry that develops inside the container 12 itself.

According to another aspect of the present invention, at least one filtering element 28 is associated with the frame 22, and has a reticular or spiral structure to aggregate and retain the limescale.

According to another embodiment, shown by way of example in figs. 6 and 7, the collector device 20 is disposed fixedly between the lower wall 13 and the upper wall 15 of the container 12.

In particular, the collector device 20 is advantageously pressed between the upper wall 15 and the lower wall 13 so that, at the moment of welding, it is compressed and clamped in position so as to be irremovable.

Preferably, the collector device 20 can be disposed in a central position inside the container 12.

Thanks to this assembly configuration, the collector device 20 is located in heat contact at least with the lower wall 13 of the container 12 which is in turn in contact with the heating element 26, and is therefore continuously super-heated during use, even in a condition where it is partly exposed by the water, which promotes and increases the formation of limescale on it.

Thanks to the continuous heat contribution supplied by the heating element 26, in fact, the lower wall 13, due to its heat inertia, continues to supply heat to the collector device 20 even when the boiler 10 is switched off: this continues to promote the accumulation and adherence of the limescale on the surfaces of the collector device 20.

This contributes to keeping the internal walls of the container 12 clean, in particular where there are the devices to control the level 33 and temperature 34; it also contributes to prevent particles of limescale from remaining in suspension in the water. According to embodiments described here, the collector device 20 can have the possible frame 22 and the filtering element 28 made in a single piece. In this way, advantageously, a reduction is obtained in the costs of the raw materials used, and in the costs of production and assembly.

According to the embodiment shown in figs. 1-5, the frame 22 defines a containing compartment 23 inside which the filtering element 28 can be installed.

According to embodiments described here, the frame 22 is made of heat- resistant material.

According to one embodiment, the frame 22 is made of metal material with high heat conductivity.

According to another embodiment, the frame 22 is made of heat-resistant plastic material.

Furthermore, the frame 22 has a plurality of through holes 24 to allow the water present in the container 12 to pass through it freely during use.

The filtering element 28 can be, for example, a metal sleeve or a woven metal wire or steel wool, or any element having a reticular or spiral structure, or a mesh structure, made of metal material with high heat conductivity.

The filtering element 28 can also be made of a ceramic based material.

The structure of the filtering element 28 increases the limescale capturing capacity since the water, with the limescale in suspension in it, easily transits through the meshes, both at entrance to and exit from the filtering element 28 and/or the frame 22. With this solution, and with the repeated passes of the water in contact with the meshes and/or the walls of the filtering element 28, and also with the contact and corresponding heat transmission with one or more of the internal walls of the container 12, a great attraction and an accentuated deposit of the limescale is obtained inside the filtering element 28.

According to one embodiment, the frame 22 and/or the filtering element 28 can be at least partly disposed near the source of heat consisting of the heating element 26, cooperating with it directly, for example with at least partial contact, or indirectly through one or more of said walls 13, 15, 17 of the container 12.

In particular, the filtering element 28 can be configured to have a big heat exchange surface with the heating element 26, as well as with one or more of the walls 13, 15, 17, thus increasing the deposit and aggregation of the limescale and increasing the confinement of the limescale inside the containing compartment 23 of the frame 22.

According to a variant embodiment, the filtering element 28 can have a density of the reticular or spiral structure, or the mesh structure, which differs in relation at least with the average level of the water inside the container 12, that is, in relation to the level of accumulation of the limescale in the filtering element 28. For example, the density of the filtering element 28 can be greater under the average level of water inside the container 12 in order to maximize the aggregation of the limescale as a function of the volume.

According to the embodiments described above, the exit hole 18, which can be selectively opened/closed for example by a cap, is configured to allow to remove the water and particles of limescale in suspension inside it that have not been trapped in the collector device 20.

According to one embodiment, shown by way of example in figs. 1 and 2, the frame 22 can be configured to have an omega-shaped cross section, the ends of which are attached to the wall of the container 12, directly cooperating with the heating element 26, and in this way determine the containing compartment 23 so as to enclose the filtering element 28.

According to another embodiment, shown by way of example in figs. 3 and 4, the frame 22 can be provided with a tubular element 30 disposed with its mouth in correspondence with the feed aperture 14 and configured to convey the water entering into the container 12 directly above the filtering element 28.

In this way, advantageously, although the average level of the water does not completely cover the filtering element 28, the water loaded through the feed aperture 14 is obliged to pass through the filtering element 28 to deposit a part of the limescale immediately.

According to another embodiment, shown by way of example in fig. 5, the frame 22 can be a wire with a helical shape around which the filtering element 28 can be wound in a spiral, in which the coils, which are disposed in contact at least with the lower wall 13, can have a pitch suitable to promote the aggregation and retention of the limescale.

According to the other embodiment shown by way of example in figs. 6 and 7, the collector device 20, or a possible filtering element 28 that makes up part of it, can have a substantially cylindrical conformation, or another section shape, for example polygonal, with an upper base and a lower base that are substantially flat, suitable to be coupled stably with the respective portions of the lower wall 13 and upper wall 15 of the container 12.

The collector device 20 and/or the filtering element 28 can have a three- dimensional structure with a pleated mesh, rolled around itself in the form of a spiral.

In this way, the pleated mesh structure increases the contact surface between the collector device 20 and the limescale.

It is clear that modifications and/or additions of parts may be made to the boiler 10 and the collector device 20 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of boiler 10 and collector device 20, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Boiler for generating steam and/or for heating water, comprising a metal container (12) provided at least with a feed aperture (14) to introduce water inside it and with a heating element (26), wherein said container (12) comprises a lower wall (13), an upper wall (15) and a lateral wall (17), characterized in that inside said container (12) there is at least one fixed limescale collector device (20) at least partly immersed in the water during use, said collector device (20) having a three-dimensional geometry that develops inside the container (12) so as to be clamped or pressed against, or in contact with, at least a portion of internal wall, lower (13) and/or upper (15) and/or lateral (17), of said container (12), said collector device (20) comprising at least one metal filtering element (28), or with a ceramic base material, with a reticular or pleated or spiral structure to aggregate and retain the limescale.

2. Boiler as in claim 1, characterized in that said collector device (20) comprises a frame (22) to support said filtering element (28).

3. Boiler as in claim 2, characterized in that said at least one frame (22) is made of a heat-resistant material.

4. Boiler as in claim 2 or 3, characterized in that said at least one frame (22) and/or said at least one filtering element (28) are disposed at least partly in contact with said heating element (26) or with the wall of said container (12) in correlation with the position of said heating element (26).

5. Boiler as in any of the claims from 2 to 4, characterized in that said at least one frame (22) is made of metal material.

6. Boiler as in any claim from 2 to 4, characterized in that said at least one frame (22) is made of heat-resistant plastic material.

7. Boiler as in any claim hereinbefore, characterized in that said at least one filtering element (28) has a density of the reticular or spiral structure, that is, of the mesh structure, that is differentiated in relation at least to an average level of the water inside the container (12).

8. Boiler as in any claim hereinbefore, characterized in that said container (12) provides a selectively openable/closable exit hole (18) configured to allow to empty the water and the particles of limescale in suspension inside said container

9. Boiler as in any claim from 2 to 8, characterized in that said at least one frame (22) defines a containing compartment (23) inside which said at least one filtering element (28) is installed.

10. Boiler as in any claim from 2 to 9, characterized in that said at least one frame (22) has a plurality of through holes (24).

1 1. Boiler as in any of the claims from 2 to 10, characterized in that said at least one frame (22) has an omega-shaped cross section, having ends attached to a wall of the container (12), directly cooperating with said heating element (26), and determines said containing compartment (23) to enclose said at least one filtering element (28).

12. Boiler as in any claim from 2 to 10, characterized in that said at least one frame (22) is provided with a tubular element (30) disposed in correspondence with said feed aperture (14), said tubular element (30) being configured to allow the water entering into said container (12) to be conveyed above said at least one filtering element (28).

13. Boiler as in any claim from 2 to 8, characterized in that said at least one frame (22) is a wire with a helical shaping, said at least one spiral filtering element (28), having spirals with a pitch suitable to aggregate and retain the limescale, being wound around said at least one frame (22).

14. Boiler as in claim 1, characterized in that said collector device (20) is disposed fixedly between said lower wall (13) and said upper wall (15) of said container (12), so that at least one lower wall and/or one upper wall of said collector device (20) is stably in contact with a corresponding portion of said lower wall (13) and/or said upper wall (15) of said container (12) and /or of said heating element (26).

15. Boiler as in claim 14, characterized in that said collector device (20) is compressed between said lower wall (13) and said upper wall (15) in a substantially central position thereof.

16. Limescale collector device (20) suitable to be installed inside a container (12) containing water during use, characterized in that said collector device

(20) has a three-dimensional geometry and it comprises at least one metal filtering element (28), or with a ceramic base material, with a reticular or pleated or spiral structure to aggregate and retain the limescale.