STEAM GENERATOR, IN PARTICULAR FOR OVENS
20220316699 · 2022-10-06
Inventors
- Francesco GUISTO (Mestre, IT)
- Giacomo DURIGON (Quinto di Treviso, IT)
- Luigino DE TOFFOLI (Mareno di Piave, IT)
- Stefano Zanella (Montebelluna, IT)
- Frederico ZOPPAS (Treviso, IT)
Cpc classification
F22B37/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24C15/327
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F22B37/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F22B1/28
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A steam generator (1), in particular for an oven, comprising a tank (3) provided with an inlet pipe (4) suitable for introducing liquid into the tank (3) and an outlet pipe (5) suitable for releasing steam from the tank (3); at least one heating element (2) adapted to heat the liquid to produce the steam; wherein the tank (3) comprises: a first chamber (31); a second chamber (32); a third chamber (33), proximal to the outlet pipe (5); wherein the first chamber (31) and the second chamber (32) are adapted to contain the liquid introduced by means of said inlet pipe (4); wherein a first partition wall (41) is provided, which partially separates the first chamber (31) and the second chamber (32) from each other; wherein a second partition wall (42) is provided, which separates at least partially both the first chamber (31) and the second chamber (32) from the third chamber (33); wherein a first passage (21) is provided which allows the steam to pass from the first chamber (31) to the second chamber (32); wherein a second passage (22) is provided which allows the steam to pass from the second chamber (32) to the third chamber (33); wherein a third passage (23) is provided which allows the liquid to pass between the second chamber (32) and the first chamber (31), near the bottom (6) of the tank (3).
Claims
1. A steam generator, in particular for an oven, comprising: a tank provided with at least one inlet pipe suitable for introducing liquid into the tank and at least one outlet pipe suitable for releasing steam from the tank; at least one heating element adapted to heat the liquid to produce the steam; wherein the tank comprises: a first chamber; a second chamber; a third chamber, proximal to the outlet pipe; wherein the first chamber and the second chamber are adapted to contain the liquid introduced by means of said inlet pipe; wherein a first partition wall is provided, which partially separates the first chamber and the second chamber from each other; wherein a second partition wall is provided, which separates at least partially both the first chamber and the second chamber from the third chamber; wherein a first passage is provided which allows the steam to pass from the first chamber to the second chamber; wherein a second passage is provided which allows the steam to pass from the second chamber to the third chamber; wherein a third passage is provided which allows the liquid to pass between the second chamber and the first chamber, in particular near the bottom of the tank.
2. The steam generator according to claim 1, wherein the first chamber is proximal to the at least one heating element, and wherein the second chamber is distal from the at least one heating element.
3. The steam generator according to claim 1, wherein the third chamber is arranged between the outlet pipe and the first chamber, and preferably between the outlet pipe and the second chamber.
4. The steam generator according to claim 1, wherein the third passage is proximal to the inlet pipe and/or wherein said third passage is partly delimited by the bottom of the tank.
5. The steam generator according to claim 1, wherein said third passage is delimited by the bottom of the tank and by the first partition wall.
6. The steam generator according to claim 1, wherein the first passage and the second passage are in an upper zone of the tank comprising the outlet pipe.
7. The steam generator according to claim 1, wherein the second passage is obtained in the second partition wall and/or wherein the first passage is at least partially delimited by the first partition wall, preferably wherein the first passage is delimited by the first partition wall and the second partition wall.
8. The steam generator according to claim 1, wherein the second partition wall comprises a first portion and a second portion which are mutually inclined; preferably wherein the first portion and the second portion form an angle, the apex of which faces a wall of the tank provided with the outlet pipe.
9. The steam generator according to claim 1, wherein a fourth passage is provided which allows the liquid to pass from the third chamber to the first chamber and/or to the second chamber; preferably wherein the fourth passage is partly delimited by a wall of the tank and/or partly by the second partition wall.
10. The steam generator according to claim 1, wherein the at least one heating element is constrained, preferably outside the tank, to a wall which delimits the first chamber.
11. The steam generator according to claim 1, wherein the first partition wall and the second partition wall are mutually transversal.
12. The steam generator according to claim 1, wherein the bottom of the tank is also the bottom of the first chamber and of the second chamber.
13. The steam generator according to claim 1, wherein the bottom of the tank forms an angle (β) with a wall of the tank; said angle (β) being greater than 90°, preferably comprised between 90° and 179° or between 90° and 140°.
14. The steam generator according to claim 1, wherein the tank comprises a fourth chamber which is proximal to the inlet pipe; wherein a third partition wall is provided, which separates at least partially both the first chamber and the second chamber from the fourth chamber; preferably wherein a passage is provided, which allows the liquid to pass from the fourth chamber to the second chamber and/or a passage which allows a passage of liquid from the fourth chamber to the first chamber.
15. The steam generator according to claim 1, wherein the tank is L-shaped.
16. The steam generator according to claim 1, wherein a venting pipe is provided preferably proximal to the inlet pipe.
17. The steam generator according to claim 1, comprising at least one additional tank adapted to be connected to the tank.
18. An oven for steam cooking and preferably also for steam cleaning the oven, comprising a steam generator according to preceding claims; preferably wherein the oven comprises at least one further tank connected to the tank of the steam generator, the further tank being in particular adapted to be used as an auxiliary reserve of liquid.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0037] The description of the invention refers to the accompanying drawings, which are provided by way of non-limiting example, in which:
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[0052] The same elements or parts have the same reference numerals.
DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION
[0053] A steam generator 1 according to the invention is described with reference to the figures.
[0054] The steam generator 1 is particularly adapted to be used in an oven 100 (
[0055] The steam generator 1 comprises a tank 3 adapted to contain the liquid, in particular water, which produces steam when heated.
[0056] To feed the water into the tank 3, the latter is provided with an inlet, in particular an inlet pipe 4.
[0057] For releasing the steam from the tank 3, the latter is provided with an outlet, in particular an outlet pipe 5.
[0058] The tank 3 has a bottom 6, or bottom wall, i.e. a surface which acts as a lower containment for the liquid introduced into the tank 3 through the inlet pipe 4. Preferably, the inlet pipe 4 is proximal to the bottom 6 of the tank 3 and the outlet pipe 5 is distal from the bottom 6. In other words, the inlet pipe 4 and the outlet pipe 5 are preferably in a lower zone and an upper zone of the tank 3, respectively. More in detail, with particular reference to
[0059] The inlet pipe 4 extends, towards the outside of the tank 3, from a wall 19 preferably proximal to the bottom 6. In particular, the wall 19 comprises two connecting portions 62, 63, preferably curved. The wall 19 is connected to the bottom 6 by means of the connecting portion 63 and is connected to the wall 18 by means of the connecting portion 62. The wall 18 and the bottom 6 are preferably opposite to each other, preferably parallel to each other. Also, preferably, the wall 19 is opposite to the wall 14. The wall 19 is preferably a side wall, in particular a lower side wall, of the tank 3.
[0060] Preferably, the portion of wall 19 which extends between the connecting portions 62, 63 is orthogonal or substantially orthogonal to the wall 18 and/or to the bottom 6.
[0061] The inlet pipe 4 and the outlet pipe 5 extend about a respective axis and preferably, but not exclusively, the axis of the inlet pipe 4 and the axis of the outlet pipe 5 mutually form an angle between 90° and 270° or between 90° and 180° or between 90° and 140°, e.g. of about 95°. Preferably, said angle is greater than 90°. Preferably, the inlet pipe 4 has a section, in particular an inner section, which is smaller than or equal to the section, in particular the inner section, of the outlet pipe 5.
[0062] To heat the water, the steam generator 1 is provided with at least one heating element 2, e.g. only one heating element 2, or heater.
[0063] The tank 3 is advantageously divided into at least three chambers or zones 31, 32, 33 communicating with each other (see in particular
[0064] A first chamber or zone 31 is preferably proximal to the heating element 2.
[0065] A second chamber or zone 32 (indicated in 5A) is preferably distal from the heating element 2; in particular, the first chamber 31 is preferably arranged between the heating element 2 and the second chamber 32.
[0066] A third chamber or zone 33 is preferably proximal to the outlet pipe 4.
[0067] In particular, a first partition wall 41 is provided, which partially separates the first chamber 31 and the second chamber 32 from each other. In
[0068] Furthermore, a second partition wall 42 is provided, which partially, or at least partially, separates both the first chamber 31 and the second chamber 32 from the third chamber 33.
[0069] Preferably, the first partition wall 41 and the second partition wall 42 are mutually transversal, e.g. mutually perpendicular or substantially perpendicular.
[0070] A first passage 21 allows the steam to pass from the first chamber 31 to the second chamber 32. Preferably, the first passage 21 is delimited by the first partition wall 41 and by the second partition wall 42.
[0071] A second passage 22 allows the steam to pass from the second chamber 32 to the third chamber 33. Preferably, the second passage 22 is obtained in the second partition wall 42. By way of non-limiting example, the second passage 22 may be formed by at least one hole, e.g. one hole, obtained in the second partition wall 42. The first passage 21 and the second passage 22 are mutually distinct.
[0072] The first passage 21 and the second passage 22 are preferably in an upper zone of tank 3, in particular, they are arranged in the upper zone which comprises also the outlet pipe 5.
[0073] The third chamber 33 is preferably arranged above the first chamber 31 and above the second chamber 32.
[0074] In particular, the third chamber 33 is arranged between the outlet pipe 5 and the first chamber 31, and between the outlet pipe 5 and the second chamber 32.
[0075] Preferably, the third chamber 33 communicates directly with the outlet pipe 5. In particular, preferably, the third chamber 33 is delimited at the top by the wall 15 provided with the outlet pipe 5.
[0076] Preferably, but not exclusively, the bottom 6 of the tank 3 is also the bottom of the first chamber 31 and of the second chamber 32.
[0077] Advantageously, the inner division of the tank 3 makes it possible to fill the tank 3 to 60% or 70% of its inner volume without releases of splashes of water from the outlet pipe 5 during the generation of steam.
[0078] In particular, the second partition wall 42 is arranged to limit the direct flow of steam from the first chamber 31 to the third chamber 33.
[0079] In particular, most of the steam produced by the heating of the liquid in the first chamber 31 passes first from the first chamber 31 to the second chamber 32, and then from the second chamber 32 to the third chamber 33, and then exits from the outlet pipe 5. The path followed by the steam is diagrammatically shown by the arrows F1, F2, F3 in
[0080] The liquid fraction of the boiling water can advantageously return to the first chamber 31, coming directly from the third chamber 33 and/or passing first through the second chamber 32 to then reach the first chamber 31. The water which returns to the first chamber 31 was previously heated. Therefore, the steam production process is particularly efficient.
[0081] In particular, a third passage 23 allows the steam to pass between the second chamber 32 and the first chamber 31. The third passage 23 is preferably near or at the bottom 6 of the tank 3. The third passage 23 is preferably near the inlet pipe 4. The third passage 23 is distinct from the first passage 21 and the second passage 22.
[0082] Preferably, but not exclusively, the third passage 23 is partly delimited by the bottom 6 of the tank 3.
[0083] Preferably, but not exclusively, the third passage 23 is delimited by the bottom 6 of the tank 3 and by the first partition wall 41.
[0084] The third passage may also be provided in other zones, e.g. may be completely or partially delimited by the first partition wall, e.g. may be obtained in the first partition wall.
[0085] The third passage 23 allows the passage of the liquid introduced into the tank 3 through the inlet pipe 4. According to the principle of communicating vessels, the liquid level in the first chamber 31 and the second chamber 32 is substantially the same, in particular when the heating element 2 is off.
[0086] The third passage 23 also allows the passage of the liquid fraction of the water from the second chamber 32 into the first chamber 31.
[0087] By way of non-limiting example, the third passage 23 may be, for example, at a distance, in particular a minimum distance, from the bottom 6 from 0 to 10 cm, or from 0 to 5 cm. In particular, the value “0” relates to the case in which the third passage 23 is partly delimited by the bottom 6 of the tank 3, e.g. when the third passage 23 is delimited by the bottom 6 of the tank 3 and the first partition wall 41 To facilitate the flow of the liquid fraction of the water towards the first chamber 31 and/or towards the second chamber 32, the second partition wall 42 preferably comprises a first portion 421 and a second portion 422 which are mutually inclined. Preferably, the first portion 421 and the second portion 422 form an angle α (indicated in
[0088] Preferably, the aforesaid angle α has a width greater than 180°, preferably between 200° and 300° or between 240° and 280, e.g. about 270°.
[0089] Note that the angle α is the angle proximal to said wall 15 formed by the two portions 421, 422.
[0090] The first portion 421 and the second portion 422 are preferably above the first partition wall 41.
[0091] Preferably, the first portion 421 and the second portion 422 are mutually consecutive.
[0092] The liquid fraction of water can reach the second chamber 32 passing through the second passage 22 and can reach the first chamber 31 through the third passage 23. In particular, through the third passage 23, the liquid can pass, in particular directly, from the second chamber 32 to the first chamber 31.
[0093] Preferably, there is a fourth passage 24 which allows the liquid to pass from the third chamber 33 directly to the first chamber 31 and/or from the third chamber 33 to the second chamber 32. Preferably, the fourth passage 24 is partly delimited by the wall 14 of the tank 3 and/or partly by the second partition wall 42.
[0094] For example, the second partition wall 42 may optionally also comprise a third portion 423 facing the wall 14 of the tank 3. The third portion 423 and the wall 14 are mutually distanced so that the fourth passage 24 is delimited, at least partially, by the third portion 423 and by the wall 14. Preferably, the distance between the third portion 423 and the wall 14 is comprised between 1 and 17.5 mm, e.g. between 2 and 10 mm.
[0095] The third portion 423 extends transversely to the second portion 422 and is preferably consecutive to the second portion 422.
[0096] Through the fourth passage 24, the liquid fraction of the water can reach, for example, the first chamber 31 and the second chamber 32 through a respective passage, preferably partly delimited by the first partition wall 41.
[0097] With particular reference to
[0098] Preferably, the heating element 2 is arranged outside the tank 3, preferably completely outside the tank 3. In particular, the heating element 2 is fixed to a face of the wall 12 which is outside the tank 3. Alternatively, the heating element 2 can be arranged, fully or partially inside the tank 3.
[0099] The wall 12 is preferably an outer wall of the tank 3.
[0100] The wall 12 is preferably substantially a cover of the tank 3.
[0101] The wall 12 is hermetically fixed with the rest of the tank 3.
[0102] Preferably, fixing means (not shown) are further provided, such as screws and nuts and/or elastic means, such as clips or pegs and/or a sealant or glue for fixing the wall 12, which can optionally be unmounted. Alternatively, the wall 12 can be co-molded with the rest of the tank 3.
[0103] Preferably, the heating element 2 is of the electrical type. For example, the heating element 2 is a sheathed resistor, i.e. a resistor capable of producing heat when electric current flows through it, provided with a metal outer casing.
[0104] Preferably, the heating element 2 extends only at the lower zone of the steam generator 1, in particular of the tank 3, and optionally also at the middle zone of the tank 3. In other words, the heating element 2 does not extend to the upper zone of the steam generator 1, in particular of the tank 3. More in detail, the heating element 2 does not extend at the third chamber 33.
[0105] The second partition wall 42 is arranged, in particular, between the two walls 14, 16 of the tank 3 opposite to each other.
[0106] Preferably, the outlet pipe 5 is proximal to the wall 14 and distal from the wall 16; and the second passage 22 is proximal to the wall 16 and distal from the wall 14. In this manner, the distance between the second passage 22 and the outlet pipe 5 is advantageously increased, to prevent the release of splashes of water from outlet pipe 5 more effectively.
[0107] Preferably, the apex 420, i.e. the edge formed between the two portions 421, 422 of the second partition wall 42, is proximal to the outlet pipe 5 and preferably the second passage 22 is distal from the outlet pipe 5.
[0108] In particular, the apex 420 is preferably proximal to the wall 14 and distal from the wall 16. Preferably, the portion 422 has a smaller surface extension than the surface extension of the first portion 421.
[0109] Preferably, as mentioned, the second passage 22 is obtained in the second partition wall 42. In particular, the second passage 22 is preferably obtained in the portion 421 of the second partition wall 42. Preferably, the second passage 22 is delimited by the second partition wall 42 and by a wall 17 of the tank 3 opposite to the wall 12 to which the heating element 2 is constrained. Preferably the second passage 22 is further delimited by the first partition wall 41.
[0110] Preferably, the wall 17 is parallel or substantially parallel to the wall 12.
[0111] Preferably, the wall 17 defines the second chamber 32.
[0112] The first partition wall 41 and the second partition wall 42 are arranged between the wall 12 and the wall 17.
[0113] In particular, the first partition wall 41 faces both the wall 12 and the wall 17 and is spaced from the walls 12, 17. More in particular, the first partition wall 41, preferably, partly delimits the first chamber 31 and partly delimits the second chamber 32. Preferably, the first partition wall 41 is parallel or substantially parallel to the wall 12. The first partition wall 41 is preferably supported by one or more supporting elements (not shown), e.g. arranged in the first chamber 31 and/or the second chamber 32.
[0114] Preferably, the second partition wall 42 extends from the wall 17 towards the wall 12. Preferably, there is a gap between the wall 12 and the partition wall 42. Preferably, the second partition wall 42 is in contact with the wall 17, although it is not excluded that a gap can be provided between the wall 17 and the second partition wall 42.
[0115] Preferably, the second partition wall 42 is transversal, e.g. perpendicular or substantially perpendicular, to the two walls 12, 17.
[0116] Preferably, the bottom 6 of the tank 3 is inclined with respect to the wall 14. For example, the wall 14 and the bottom 6 form an angle β (indicated in
[0117] Advantageously, in this manner, when the wall 14 is arranged vertically, the bottom 6 is inclined so that water can be released from the pipe 4 by gravity or with the help of a pump or solenoid valve, avoiding unwanted water stagnation.
[0118] Preferably, but not exclusively, the steam generator 1 is substantially L-shaped. The L-shaped shape is particularly advantageous to optimize the size of the steam generator 1 with respect to the oven 100, without having to reduce the capacity of the tank 3.
[0119] With particular reference to
[0120] The L-shaped design makes it possible to take advantage of both the space at the side of the fan and the space below the fan.
[0121] Observing
[0122] Furthermore, the steam generator 1, in particular the tank 3, can be produced with the same mold both when the steam generator 1 is intended to be mounted in the rear right zone and in the rear left zone of the oven 100.
[0123] The inlet pipe 4 can be connected to one or more tanks (not shown) adapted to supply the steam generator 1. The outlet pipe 5 can be connected to an additional pipe (not shown) which can conduct the steam into the cooking compartment of the oven 100.
[0124] When the steam generator 1 is L-shaped, both the wall 16 and the wall 19, which is preferably the wall provided with the inlet pipe 4, are opposite to the wall 14. The distance between the wall 14 and the wall 16 is smaller, in particular always smaller, than the distance between the wall 14 and the wall 19.
[0125] Similarly, both the wall 15 and the wall 18 are opposite the bottom 6. The distance between the bottom 6 and the wall 18 is smaller, in particular always smaller, than the distance between the bottom 6 and the wall 15.
[0126] More in particular, the wall 14 preferably extends from the wall 15 to the bottom 6, to which it is connected by means of the connecting portion 64, preferably curved. The wall 16 is shorter than the wall 14. The wall 18 is connected to the wall 16, preferably by means of a connecting portion 61, preferably curved. Preferably, the wall 18 is parallel or substantially parallel to the bottom wall 6.
[0127] Preferably, the tank 3 is provided with a venting pipe 9 which prevents, in particular, the inner pressure of tank 3 from increasing excessively. The venting pipe 9 can optionally be connected to an additional pipe (not shown) which, in turn, can be connected directly to the oven cavity, or to one or more auxiliary tanks or boxes, or the venting pipe can be left free in the atmosphere.
[0128] Preferably, the venting pipe 9 is in a lower zone of the tank 3, preferably near the inlet pipe 4. For example, the wall 19 is provided both with the inlet pipe 4 and the venting pipe 9.
[0129] Preferably, but not exclusively, the tank 3 further comprises a fourth chamber 34 which is proximal to the inlet pipe 4. Preferably, the inlet pipe 4 communicates directly with the chamber 34.
[0130] A third partition wall 43 is provided, which separates at least partially both the first chamber 31 and the second chamber 32 from the fourth chamber 34.
[0131] The third partition wall 43 is transversal, preferably perpendicular or substantially perpendicular to the first partition wall 41.
[0132] A passage 25 (
[0133] A passage 26 may be provided (
[0134] Preferably, the third partition wall 43 further comprises two mutually inclined portions 431, 432. Preferably, the portion 431 and the portion 432 form an angle γ (indicated in
[0135] It is worth noting that the angle γ is the angle proximal to said wall 19 formed by the two portions 431, 432.
[0136] Preferably, the apex 430 is proximal to the inlet pipe 4 and preferably the passage 25 is distal from the inlet pipe 4. Preferably, the passage 25 is proximal to the wall 18. In particular, the passage 25 is preferably delimited by the first partition wall 41, the third partition wall 43, the wall 17 and the wall 18.
[0137] It has been experimentally observed that the presence of the third partition wall 43 contributes to improve the water flow in tank 3 and to improve the homogeneity of steam coming out of steam generator 1.
[0138] Preferably, the steam generator 1, in particular the tank 3, is provided with at least two connecting portions 7a, 7b which constrain the steam generator 1 to the body of the oven 100. For example, each connecting portion 7a, 7b comprises a hole in which a respective screw can be inserted (not shown).
[0139] Some preferred, but not exclusive, dimensional details which can be considered individually or in any combination are provided below.
[0140] Preferably, the inner volume or maximum capacity of the tank 3, in particular its maximum capacity, is from 50 ml to 750 ml; and/or the inner volume of the third chamber 33 is lower than the inner volume of the first chamber 31 and/or than the inner volume of the second chamber 32, e.g. from 2 to 20 times lower; and/or
[0141] the section area of the second passage 22 is larger than the section area of the first passage 21; and/or
[0142] the section area of the second passage 22 is comprised between 150 and 1400 or between 230 and 930 mm.sup.2; and/or
[0143] the section area of the first passage 21 is between 60 and 590 or between 95 and 390 mm.sup.2; and/or
[0144] the section area of the third passage 23 is between 75 and 700 or between 115 and 460 mm.sup.2; and/or
[0145] the distance between the wall 12 and the wall 17 is between 5 and 150 or between 10 and 90 mm.
[0146] With regard to materials, the tank 3 is preferably made of plastic, e.g. thermoplastic polymer such as PPS, PC, PA, PP or POM, or metal, e.g. steel.
[0147] The first partition wall 41, is preferably made of metal, e.g. steel, but can also be made of plastic.
[0148] Preferably, the second partition wall 42 and, when provided, the third partition wall 43 are preferably made of plastic, e.g. thermoplastic polymer, e.g. such as PPS, PC, PA, PP or POM, but can also be made of metal, e.g. steel.
[0149] Note that the aforesaid walls 12, 14, 15, 16, 17, 18, 19 and 6, i.e. the bottom 6, and the aforesaid connecting portions 61, 62, 63, 64, 65, 66 are preferably outer walls of the steam generator 1, in particular, they comprise an outer face outside the tank 3 and an inner face inside the tank 3, opposite to the outer face.
[0150] Note that, one or more additional chambers or zones may be provided, divided by means of one or more additional partition walls or portions of partition walls, in addition to the three chambers or zones 31, 32, 33, or the four chambers or zones 31, 32, 33, 34.
[0151] For example, the third chamber or zone 33 can be divided into two chambers or zones by means of a partition wall, or into three chambers or zones by means of two partition walls and so on.
[0152] Note that the passages 21, 22, 23, and when provided, the passages 24, 25, 26 are, in particular, inside the tank 3; in particular completely inside the tank 3.