ES3055500T3 - Device for generating steam and household appliance comprising such a device - Google Patents

Abstract

A steam generating device for a steam furnace consists of a water storage chamber with an inlet and outlet, and a heating chamber for the water drawn from the storage chamber. The heating chamber has a steam outlet and an inlet connected to the water outlet. A heating element for heating and evaporating the water is located outside the chamber. The water storage chamber is located laterally next to the heating chamber, separated by a partition open at the bottom. The steam generating device is wider than it is tall in the vertical direction perpendicular to the heating chamber and at least five times wider than it is thick, making it relatively flat. The heating element is located outside the heating chamber, on one of the flat sides of the casing.

Description

[0001] DESCRIPTION

[0002] Steam generating device and household appliance with such a device

[0003] The invention relates to a steam-generating device, preferably for household appliances such as ovens or steam cookers, but also, for example, for washing machines. The device comprises a water reservoir and a heating chamber containing a heating element for heating and evaporating the water. Furthermore, the invention relates to a household appliance with such a steam-generating device, in particular an oven or a steam cooker, and, where applicable, also a washing machine or a dishwasher.

[0004] A device of this type for generating steam is known from document DE 102007048 567 A1. It is designed as a kind of circuit and has a water storage chamber on one side. This chamber has a water inlet and a water outlet. The water flows downwards like a conduit, then turns to the side and returns in a ring shape to the water storage chamber. On the right side, where the water flows upwards, a water pipe is formed from another component, and two elongated heating elements are located on the outside. These heat the flowing water to a temperature high enough that it can escape as steam from the upper end of the return line to the water storage chamber, which corresponds to a steam outlet. Thanks to this design, the water can circulate and heat up during its path until steam is produced.

[0005] US Patent 2022/186924 A1 describes a steam-generating device comprising a vertically oriented water chamber. A flat heating element is provided in a narrower lower section on a side wall to heat the water in the water chamber and generate steam, for example, for a steam oven. Above this is a slightly wider chamber that serves as the steam zone, from which a steam outlet rises. Within the steam zone is a grid-like partition wall to contain the bubbling, boiling water and prevent water droplets from being carried by the steam toward the outlet.

[0006] Patent EP 2 309 910 B1 discloses a nozzle for a steam cleaner, wherein the steam cleaner has a device for generating steam. In this case as well, a heating chamber has been provided for generating steam from heated water.

[0007] Another device for generating steam, such as one that can be used, for example, in a steam furnace, is known from patent EP 0 374 863 B1. It provides a water tank with a heating chamber and a heating device for generating steam for use in the steam furnace.

[0008] Task and solution

[0009] The invention is based on the task of creating a device mentioned at the beginning with which the problems of the current state of the art can be eliminated and, in particular, it is possible to evaporate water quickly and energy-efficiently to obtain steam, as well as to arrange or house the device in a household appliance mentioned above.

[0010] This task is accomplished by a device with the features of claim 1, as well as by an appliance with the features of claim 10. The advantageous and preferred embodiments of the invention are the subject of the other claims and are explained in more detail below. Some of the features are described only for the steam-generating device or only for the appliance. However, they must be applicable independently and autonomously to both the device and the appliance. The text of the claims expressly refers to the content of the description.

[0011] The steam generating device includes a water storage chamber with a water inlet and outlet. The water inlet is used to fill the storage chamber, primarily from the outside, either through a pipe connected to a valve or manually via a fitting. The device also includes a heating chamber where the water from the storage chamber is stored and heated to generate steam. The heating chamber has an inlet connected to the water outlet for the flow of the fluid. The water outlet and inlet of the heating chamber may be identical, for example, an opening in a wall. The heating chamber also has a steam outlet through which the steam generated within it can be released. A corresponding steam pipe can be connected to this outlet, leading to a specific point of use for the steam. Additionally, the device includes a heating element located within the heating chamber. This element heats and evaporates the water in the heating chamber. It is advantageous for the heating device to be an electric heating device, in particular with a resistance heating element that heats by contact or heats the water and evaporates it.

[0012] According to the invention, the water storage chamber is located laterally next to the heating chamber. Therefore, they do not surround each other; that is, the heating element does not surround the water. Furthermore, the device is wider in the direction extending from the heating chamber to the water storage chamber than in the vertical direction or the direction perpendicular to it. The device is also at least five times wider in the horizontal direction than in the horizontal thickness direction perpendicular to it. Therefore, it can be said that the device as a whole is advantageously flat in its vertical position and wider than it is tall. This design allows for the simple and compact integration of the device into a household appliance mentioned above, for example, on an exterior side, particularly the rear, of said appliance or, where applicable, in a thermally insulated treatment chamber, such as the chamber of a steamer or a conventional oven. Thanks to the flat design of the device as a whole, as well as, advantageously, of the heating chamber itself, there are at least one, or indeed two, outer faces that are relatively large and can therefore be very well covered with a flat heating device for heating.

[0014] In another embodiment of the invention, the water storage chamber and the heating chamber can be provided to form a single structural unit with a common housing. This housing can be advantageously manufactured by plastic injection molding, particularly in two or three pieces. These individual pieces can then be assembled to form the structural unit or housing. The heating device can then be placed within it. By being manufactured as a single structural unit, it is easier to handle and, in particular, to install in an appliance. Furthermore, electrical connections are also easier, so that the device or structural unit has only one external connection point, preferably in the form of a multi-plug. This makes final installation with the appliance easier, faster, and error-free.

[0016] In another possible embodiment of the invention, the aforementioned building unit may have a square exterior shape, i.e., it may have a relatively simple design. In this case, the thickness may be even less than 20% of the width in the horizontal direction, for example, as low as 5%. The flatter the heating chamber, the larger, in comparison, the surface area of one of the flat exterior sides on which a heating device can be placed. Thus, the heating device can also be larger and more powerful.

[0018] In a further embodiment of the invention, it is advantageous that, within a single housing, i.e., a single common housing according to the prior embodiment, the water storage chamber and the heating chamber are formed and separated from each other by a dividing wall of the housing. In this way, the housing can have, so to speak, a single internal volume, with the separation achieved by means of the dividing wall arranged within it. The aforementioned water outlet from the water storage chamber can correspond to the inlet of the heating chamber and can be formed particularly easily by means of an opening and/or a break in the dividing wall of the housing. In this way, costly pipes, channels, or the like are not required, which could involve manufacturing and assembly effort, as well as the risk of leaks. All the water leaving the water storage chamber necessarily flows into the heating chamber. It can also be provided that between the water storage chamber and the heating chamber there is only a single passage or a single opening or break in the dividing wall of the housing.

[0020] In a simplified configuration, which is not part of the invention, the building unit can be envisaged as essentially consisting of a water storage chamber and a heating chamber, both open or undivided and connected to each other. In this way, water can advantageously flow from the water storage chamber to the heating chamber automatically and effortlessly. Neither the water storage chamber nor the heating chamber is subdivided, which reduces manufacturing and assembly costs. The aforementioned heating device can advantageously cover an entire side or the outer side of the heating chamber. In this way, a high heat output can be applied to the water in the heating chamber. This heating device can act on at least the majority of the cross-section of the heating chamber.

[0022] In the invention, another dividing wall is provided within the heating chamber, effectively dividing it once more. This divides the chamber into two zones, each with at least two connecting channels for fluid conduction. It is particularly preferable to have a connecting channel in the upper zone of the heating chamber, preferably the highest zone. This dividing wall may have a corresponding opening and/or interruption, for example, similar to that described above for the housing dividing wall.

[0024] [0015] The upper connection channel is preferably located above the usual water level in the device or structural unit. In this way, steam can flow primarily or even exclusively through the upper connection channel from one zone to another, with the steam exiting mainly from the other zone. It is advantageous to have another connection channel in the lower zone of the heating chamber, and it is especially advantageous if this is an opening or break in the intermediate wall. This other connection channel must always run below the water level to ensure a constant flow of water.

[0025] The subdivision of the heating chamber by an intermediate wall results in, on one side, a heating zone in which or for which the heating device is arranged. The heating device may cover a lateral surface of the heating chamber or of the heating zone within the heating chamber. The other zone is a steam zone, from which the steam outlet mentioned above emerges. Through the aforementioned upper connecting channel, steam may also flow from the heating zone to the steam outlet, passing through the upper part of the steam zone. In this way, it can be ensured, in particular, that no heating device is arranged within the steam zone. Thus, for example, it can be ensured that there is no boiling or simmering water below the steam outlet, which could otherwise expel small droplets of water towards the steam outlet.

[0026] In the invention, the aforementioned steam zone is located between the water storage chamber and the heating zone. Thus, the water storage chamber and the heating zone are separated from each other by the steam zone. This allows the steam zone to form, so to speak, a kind of thermal insulation between the heating zone and the water storage chamber. In this way, the heating device is prevented from transferring too much thermal energy to the water storage chamber, which under certain circumstances would result in energy loss.

[0027] In an advantageous embodiment of the invention, the heating device is arranged on the outside of the heating chamber. The heating device advantageously has a flat or flattened shape. In particular, it may cover at least 20% of the outer surface of the heating chamber or heating zone. Most advantageously, it covers at least 30% to 40%, and in particular at least 30% to 40%, of the outer surface of the heating zone of the heating chamber.

[0028] In another embodiment of the invention, the heating chamber may be provided to have two flat or smooth outer surfaces facing each other. In the aforementioned preferred embodiment of the flat-designed heating device, this is perfectly possible. In this case, it may be advantageous to provide that the heating device is arranged on only one of the aforementioned flat or smooth outer surfaces. The other flat outer surface is then designed without a heating device or is not heated. It is advantageous for this to be the outer surface facing the functional units of the appliance, such as an oven chamber or a treatment chamber.

[0029] One way to position the heating device in the housing or unit within the heating chamber area is to have an opening or hole in the aforementioned outer surface. This opening can occupy between 5% and 50% of the heating device's outer surface. The heating device then covers this hole, which has the main advantage of bringing the heating device into direct contact with the water in the heating zone or heating chamber. This ensures rapid and efficient water heating. In this way, at least over a significant or predominant surface area of the heating device, particularly more than 60% of its surface, the heat transfer between the heating device and the water in the heating chamber can be kept very low. In this case, the heating device must be large relative to the surrounding area in the heating chamber.

[0030] In an advantageous embodiment of the invention, the heating device is a thick-film heating device. This is manufactured by applying a thick-film heating element directly onto a metal support. The heating device with the heating support can be arranged on an outer side of the heating chamber. Although these thick-film heating devices or thick-film heating elements are more expensive to manufacture, they have a very good ratio between their own weight or mass and their heat output and heating surface area. Due to the relatively low energy consumption for their own heating, more heat can be transferred to the water over a larger surface area.

[0031] In another advantageous embodiment of the invention, the heating device may be provided to be a thick-film heating device, wherein, advantageously, a thick-film heating element is applied directly onto a mechanical heating support. The heating device with the heating support may then be arranged on an outer side of the heating chamber, for example, as mentioned above.

[0032] [0023] It is possible that the water inlet and/or steam outlet may protrude upwards. It can be foreseen that both the water inlet and the steam outlet may protrude upwards. This may correspond to a casing described above. In a further advantage of the invention, the water inlet and/or steam outlet protrude upwards, facilitating the automatic ascent of the steam. The upward-protruding aspect of the water inlet is considered less important, as it is a suitable location for such an inlet without any risk of water escaping. The upward-protruding steam outlet has the advantage that the steam can escape unobstructed upwards and into the interior of the apparatus.

[0033] In an advantageous improvement of the invention, a drain outlet may be located within the water storage chamber. Just as the steam outlet must be located from an upper area of the water storage chamber and/or the heating chamber, this outlet may be located from a lower area or the lowest point of the water storage chamber. In this way, the most complete drainage possible can be achieved. This drain outlet should not be confused with the water outlet provided for in the invention, described above, which connects the water storage chamber and the heating chamber to each other for the passage of water. However, such a drain outlet is not mandatory, since the remaining water could also evaporate through the operation of the heating device. In this way, the water storage chamber and the heating chamber can also be dried.

[0034] A household appliance according to the invention comprises a treatment chamber arranged in an appliance housing and the aforementioned steam-generating device. The appliance and the steam-generating device can be controlled by a single control system, for which a display or user interface may advantageously be provided. The steam-generating device is advantageously arranged at the rear of the household appliance, with its flat design oriented so as to increase the appliance's depth as little as possible.

[0035] These and other features are derived not only from the claims but also from the description and drawings. Individual features, whether used separately or in combination as subcombinations, may be realized in one embodiment of the invention and in other fields, and may constitute advantageous and protectable embodiments, for which protection is claimed herein. The division of the application into individual sections and subheadings does not limit the general validity of the statements made therein.

[0036] Brief description of the drawings

[0037] The drawings schematically represent examples of embodiments of the invention, which are explained in more detail below. The drawings show:

[0038] Fig. 1

[0039] a schematic rear view of a steam oven according to the invention as a domestic appliance,

[0040] Fig. 2

[0041] a steam generator according to the invention in a first front view configuration,

[0042] Fig. 3

[0043] the steam generator of fig. 2 in side view,

[0044] Fig. 4

[0045] a steam generator according to the invention in a second front view configuration,

[0046] Fig. 5

[0047] the steam generator of fig. 4 in side view, and

[0048] Fig. 6

[0049] the steam generator of fig. 4 in top view from above.

[0050] Detailed description of the implementation examples

[0051] Figure 1 shows a highly simplified rear view of a steam oven 11 according to the invention, as a domestic appliance, as known in the prior art. It has a casing 12, inside which is an oven chamber, not shown here but known in the prior art, which constitutes the treatment chamber mentioned at the beginning. At the rear 13 of the steam oven 11 is a steam generator 15 according to the invention. It has two known flexible hoses, one for water supply and the other for steam outlet. This will be explained in more detail below. The steam generator 15 is arranged outside the casing 12, so that it is isolated from the oven chamber, for example, by thermal insulation in the casing 12. This also facilitates assembly, repair, and maintenance.

[0052] Figure 2 shows the steam generator 15 according to the invention in a first enlarged configuration and in front view. As can be seen from the side view in Figure 3, it has an external shape similar to a block or a parallelepiped. The casing 16 of the steam generator 15 is a single piece, although it is preferable to manufacture it in two pieces or with a double casing and then assemble it appropriately. The width of the casing 16 is approximately 25% greater than its height. The thickness, as shown in Figure 3, is slightly less than 15% of the width. Therefore, the casing 16 is relatively flat in the vertical orientation.

[0053] To the left of the housing 16 is a water storage chamber 18. Water W can be introduced into the water storage chamber 18 via a water inlet 20 located at the top, through the aforementioned flexible tube, preferably by means of a pump and/or a dosing device. This water W is then present in the water storage chamber 18 at a predetermined level P. This level can be monitored, if necessary, by sensors, such as those known in the prior art, for example, according to EP 1870641 A2, and maintained at a predetermined height. An optional drain outlet 22 is provided at the bottom of the water storage chamber 18. Excess water that is no longer needed can be drained here to avoid hygienic issues. Similarly, cleaning fluid, for example, for descaling, which must not evaporate, can also be drained here.

[0054] A water outlet 21 is formed from the water storage chamber 18 because a vertical partition wall 25 does not extend to the bottom of the water storage chamber 18 or the housing 16, but terminates, for example, between 2 cm and 5 cm above it. To the right of the partition wall 25, a heating chamber 28 for the water W, described at the beginning, is formed, in which the same level P for the water W is established. The water outlet 21 thus simultaneously forms, as a simple opening, the inlet of the heating chamber 30.

[0055] At the top of the heating chamber 28 there is a steam outlet 31 leading to the flexible hose described above. A drain outlet or similar is not required from the heating chamber 28, as this is served by the drain outlet 22 of the water storage chamber 18. The bottom of the housing 16 can also be sloped towards the drain outlet 22 so that all the water can be drained properly.

[0056] On the flat side 33 of the housing 16, there is an opening 34 represented by dashed lines. This opening 34 is closed by a flat heating device 35, which is advantageously designed as the thick-film heating device described above. For this purpose, it may feature, in the known manner, a metallic heating support onto which a thick-film heating element is applied. This is well known in the prior art. A gasket, for example, made of silicone, may be provided between the flat side 33 of the housing and the heating device 35 to securely seal the opening 34. This allows the heating device 35 to be removed and replaced if necessary. Alternatively, the heating device 35 can be glued to the flat side 33 of the housing, thereby also closing or sealing the opening 34. Electrical or similar connections for the heating device 35 are not shown. A cover or similar item, for example also made of plastic, should also be placed over it to protect the heating device 35 from damage and to electrically disconnect or isolate it.

[0057] The partition wall 25 can be fitted as a separate piece to the housing 16, for example, glued in place, to divide it into the water storage chamber 18 on one side and the heating chamber 28 on the other. Alternatively, if the housing 16 is made of two joined half-shells, it can be formed wholly, partially, or halfway from one of these half-shells. Joining them together forms the completed partition wall 25.

[0058] Furthermore, the illustration shows that the heating device 35 only extends slightly above the intended level P. Through the opening 34, the water W can reach the heating device 35 directly and be heated as directly and efficiently as possible. Here, the heating device 35 covers approximately 60% to 70% of the outer surface of the flat side of the casing 33 in the heating chamber 28. Symmetrically, another heating device for the heating chamber 28 could also be provided on the opposite flat side of the casing. However, in that case, additional thermal and/or electrical insulation of the steam generator 15 from the rear 13 of the casing 12 of the steam furnace 11 would be required.

[0059] Furthermore, by means of the upper 15% to 20% of the heating device 35, the interior of the heating chamber 28 can also be heated above level P, thereby further heating the steam present there. Alternatively, steel wool or similar material can be placed in the heating chamber 28 to reduce calcification and decrease the formation of bubbles or boiling turbulence.

[0060] In addition to the sensors mentioned above for detecting and adjusting the P level, other sensors, in particular temperature sensors, may be provided for monitoring the heating device 35 or the amount of steam generated. These are known in the prior art and can be advantageously positioned on the steam generator 15 or its housing 16.

[0061] [0038] Figures 4 to 6 show a second version of a steam generator 115 according to the invention, which could be positioned in the same way in the steam furnace 11 as shown in Figure 1. The steam generator 115 also has a casing 116 with the same external dimensions as the previous one. A water storage chamber 118 provided on the left has a water inlet 120 at the top and a drain outlet 122 at the bottom left. The water storage chamber 118 is enclosed by a partition wall 125 on the right. A water outlet 121 is provided at the bottom right of the partition wall 125.

[0062] Unlike the first configuration, to the right of the dividing wall 125 there is a steam chamber 137, which receives water through the water outlet 121. The steam chamber 137 is separated from the heating chamber 128 located to its right by a dividing wall 138. Between the steam chamber 137 and the heating chamber 128, a lower passage 139 is formed at the lower end of the dividing wall 138, and an upper passage at the upper end of the dividing wall 138. Water W flows through the lower passage 139. Steam flows through the upper passage 140, specifically from the heating chamber 128 to the steam outlet 131. The configuration of the dividing wall 138 can be similar to that described above for the dividing wall 125. The advantage of the intermediate wall 138 in this case is that, thanks to the intermediate wall 138, which rises a lot, and at the relatively small upper passage 140, splashed water droplets or similar cannot escape with the steam coming out through the steam outlet 131. These would be very annoying inside the steam furnace 11. Thus, the dividing wall 138 can serve here as a kind of droplet separator.

[0063] Figure 4 also shows that the heating device 135 is narrower than the one in Figure 2, specifically about 30% narrower. This can be compensated for by a higher power density. Therefore, although there is also water in the steam chamber 137, it is not heated directly. The steam outlet 131 is located directly above it.

[0064] In the top view of the steam generator 115, as shown in Figure 6, it can be seen that the dividing wall 125 and the intermediate wall 138 extend continuously from the flat front of the casing 133 to the rear. Furthermore, the blocky or parallelepiped shape of the casing 116 is also clearly visible. This also reveals the arrangement of the flat water storage chamber alongside the flat steam chamber and heating chamber, which, except for the steam chamber, also applies to the first configuration of the steam generator 15. Therefore, it is relatively flat and can be installed in a space-saving appliance. Thanks to its relatively large design, a large heating element can be installed to quickly and efficiently evaporate the water.

Claims (12)

1. CLAIMS 1. Steam generating device for a household appliance (11), comprising: - a water storage chamber (118) having a water inlet (120) and a water outlet (121), - a heating chamber (128) for water (W) from the water storage chamber (118), which has a heating chamber inlet connected to the water outlet (121) and a steam outlet (131), - a heating device (135) in the heating chamber (128) for heating and evaporating the water (W) inside, where - the water storage chamber (118) is arranged laterally next to the heating chamber (128), - The device is wider in an extension direction from the heating chamber (128) to the water storage chamber (118) than it is tall in a vertical direction perpendicular to it, and is at least 5 times wider than it is in a thickness direction perpendicular to it. - in the heating chamber (128) there is an intermediate wall (138) that divides the heating chamber (128) into two zones, which have at least two connection channels (139) for fluid conduction connection between them, - the zones are a heating zone and a steam zone, - the heating device (135) is arranged in the heating zone, - from the steam zone comes the steam outlet (131), characterized by the fact that The steam zone is located between the water storage chamber (118) and the heating chamber (128). 2. Device according to claim 1, characterized in that the water storage chamber (118) and the heating chamber (128) form a structural unit with a single common housing (116), preferably manufactured by plastic injection molding. 3. Device according to claim 1 or 2, characterized in that the structural unit has the shape of a parallelepiped, where preferably the width in the horizontal direction is greater than the height in the vertical direction and where, in particular, the thickness in the horizontal direction is between 5% and 20% of the width in the horizontal direction. 4. Device according to any of the preceding claims, characterized in that the water storage chamber (118) and the heating chamber (128) are separated by a dividing wall of the housing (125) and the water outlet (121) corresponds to the inlet of the heating chamber and is formed by an opening (121) and/or an interruption in the dividing wall of the housing (125). 5. Device according to any of the preceding claims, characterized in that the heating device (135) is arranged on the outside of the heating chamber (128), wherein the heating device (135) is preferably designed to be flat and covering, in particular, at least 20% of the outer surface of the heating chamber (128). 6. Device according to claim 5, characterized in that the heating chamber (128) has two opposite flat or smooth outer sides, wherein the heating device (135) is preferably arranged only on one of the outer sides and the other flat outer side is without a heating device (135). 7. Device according to any of the preceding claims, characterized in that the heating device (135) is a thick-film heating device, wherein, in particular, a thick-film heating element is applied directly onto a metallic heating support, the heating device (135) being arranged with the heating support on an outer side of the heating chamber (128). 8. Device according to one of the preceding claims, characterized in that the water inlet (120) and/or the steam outlet (131) protrude upwards, preferably away from the housing (116) according to claim 2, in particular from an upper area of the water storage chamber (118) and the heating chamber (128), respectively. 9. Device according to one of the preceding claims, characterized in that the water storage chamber (118) has a drain outlet (122), in particular from a lower area or the lowest point of the water storage chamber (118). 10. Household appliance with a device for generating steam according to one of the preceding claims, wherein the appliance (11) has a housing (12) and a treatment chamber disposed in the housing (12), wherein the device (115) for generating steam is disposed outside the treatment chamber. 11. Household appliance according to claim 10, characterized in that the household appliance (11) is an oven or a steamer. 12. Household appliance according to claim 10 or 11, characterized in that the device (115) for generating steam is arranged on the outside of the housing (12), preferably on the back (13) of the household appliance (11).