EP3141840B1

EP3141840B1 - Heat exchanger for a domestic boiler or a water heater

Info

Publication number: EP3141840B1
Application number: EP16187773.3A
Authority: EP
Inventors: Massimo Giacometti
Original assignee: Riello SpA
Current assignee: Riello SpA
Priority date: 2015-09-08
Filing date: 2016-09-08
Publication date: 2019-12-25
Anticipated expiration: 2036-09-08
Also published as: ES2774808T3; ITUB20153485A1; PL3141840T3; EP3141840A1

Description

The invention relates to a heat exchanger for a domestic boiler or a water heater.
In particular, the invention relates to a heat exchanger comprising a casing; and a tubular member, which is wound, in a helix shape, about a given axis, so as to form a plurality of adjacent coils, which are housed inside the casing. The tubular member, wound in a helix shape, is flown through by a liquid, usually water, while combustion fumes or, more generically, hot gases containing water vapour flow in the casing to release their heat to the liquid. The coils are spaced apart from one another so as to form an empty space where the combustion fumes can flow. In particular, the heat exchanger described above is configured for defining a path for the hot gases extending between the adjacent coils, so as to optimize the heat exchange between the hot gases and the liquid. Documents EP 1,627,190 B1 ; EP 1,600,708 A1 ; EP 1,750,070 A1 ; EP 1,750, 069 A1 ; EP 1,752,718 A1 show some significant examples of condensing heat exchangers used in domestic boilers. Another example of heat exchanger is disclosed in DE 10051219 , which discloses the features of the preamble of claim 1.
An object of the invention is to provide a heat exchanger of the type described above, which is easy to be manufactured and to be installed in a domestic boiler or in a water heater.
According to the invention there is provided a heat exchanger for a domestic boiler or a water heater, the heat exchanger comprising a casing, which comprises a lateral wall extending about a longitudinal axis and a first and a second end wall coupled, on opposite sides, to the lateral wall; a tubular member, which is configured for conveying water, and is housed in the casing; and two clamps, each of which is arranged outside the casing, is connected to the first and the second end wall so as to clamp the lateral wall between the first and second end wall; the heat exchanger being characterized in that each clamp is configured for being mounted on a support structure so as to fix the heat exchanger to the support structure. The clamp basically has two functions: on the one hand, it is used to assemble the heat exchanger and, on the other hand, it is used to mount the heat exchanger inside a boiler of a water heater.
In particular, the first and the second end wall have respective annular grooves configured for housing, respectively, the opposite edges of the lateral wall. This configuration makes the assembly of the casing particularly easy, as users simply need to exert, and keep exerting, a force upon the first and the second end wall along the given axis.
In particular, each clamp is sized so that the first and the second end wall exert a compression force along the longitudinal axis upon the lateral wall.
In order to fix the clamps, the first end wall has two first anchoring portions and the second end wall has two second anchoring portions, each of which is aligned with a respective first anchoring portion in a direction parallel to the longitudinal axis.
In particular, each clamp comprises a base; a first and a second wing configured for being connected to the first and second end wall; and a third wing configured for mounting the heat exchanger to the support structure.
In a practical and convenient manner, each clamp is made by folding a metal sheet blank, wherein the first and the third wing are end wings bent at a right angle with respect to the base about respective bending lines, while the second wing is sheared, partly, from the base and bent with respect to the base about a further bend line.
Basically, the base is parallel to the longitudinal axis, while the bend lines and the further bend line are parallel to each other and transversal to the longitudinal axis. The first, the second and the third wing are preferably bent at a right angle with respect to the base.
Furthermore, the first wing has a length longer than the length of the second wing and shorter than the length of the third wing. The first and the second wing are provided with respective holes for the fixing by means of screws, while the third wing is provided with openings, each of which is aligned with a respective hole of the first or the second wing.
The different length of the first, the second and the third wing and the opening in the third wing (which is longer) allow an easy access to the screws by means screwdrivers.
Further features and advantages of the invention will be best understood upon perusal of the following description of a non-limiting embodiment thereof, with reference to the accompanying drawing, wherein:

Figure 1 is an elevation view, with parts removed for greater clarity, of a heat exchanger according to the invention;
Figure 2 is a section view, with parts removed for greater clarity, of the heat exchanger of Figure 1 along the section lines II-II; and
Figure 3 is a perspective view, partially exploded and with parts removed for greater clarity, of the heat exchanger of Figure 1.

With reference to Figure 1, number 1 indicates, as a whole, a heat exchanger, which, in this specific case, is a condensing heat exchanger for the production of hot water in a domestic boiler or in a water heater, which are not shown in the accompanying Figures.
With reference to Figure 2, the heat exchanger 1 extends along a longitudinal axis A and comprises a casing 2 with a cylindrical shape; and a tubular member 3, which is partly wound, in a helix shape, about an axis A so as to form coils 4 and two straight end sections, which are not shown in the accompanying Figures, and is housed in the casing 2. Basically, the tubular member 3 is obtained through extrusion and is subsequently wound in a helix shape except for two end sections, not shown in the accompanying Figures, which preserve the straight configuration. The casing 2 comprises a lateral wall 5, which has a substantially cylindrical shape and is preferably made of a metal material, such as for example aluminium, or of a plastic material; an end wall 6 with a substantially annular shape and an end wall 7 substantially shaped like a disc. The end walls 6 and 7 are coupled to the lateral wall 5 so as to form the casing 2 and a combustion fumes circulation chamber. In this specific case, the end wall 6 has a central opening 8 and is configured for supporting a burner with a cylindrical shape, not shown in the accompanying Figures, which is partly arranged inside the combustion fumes circulation chamber. Alternatively, the hot fumes are conveyed through the central opening 8. The lateral wall 5 comprises an opening 9 (Figure 1) for the extraction of the combustion fumes and an opening 10 for the extraction of the condensate (Figure 1). The openings 9 and 10 are made along the lateral wall 5.
With reference to Figure 1, the end walls 6 and 7 comprise respective tubular sections 11 and 12, which are configured for housing the end sections, not show, of the tubular member 3 and, at least partly, respective hydraulic fittings 13 and 14 to connect the tubular member 3 to conduits of a hydraulic circuit, which is not shown herein.
With reference to Figure 2, the heat exchanger 1 comprises two clamps 15, each of which is arranged outside the casing 2, is connected to the first and the second end wall 6, 7 so as to clamp the lateral wall 5 between the first and second end wall 6, 7, and is configured for being mounted on a support structure 16 so as to fix the heat exchanger to the support structure 16. More in detail. The support structure 16 is part of a bearing framework of the condensing boiler of the water heater.
The end walls 6 and 7 have respective annular grooves 17 and 18 configured for housing, respectively, the opposite edges of the lateral wall 5. The clamps 15 are sized so that the end walls 6 and 7 exert a compression force along the longitudinal axis A upon the lateral wall 5.
With reference to Figure 3, the end wall 6 has two anchoring portions 19 and the end wall 7 has two anchoring portions 20, each of which is aligned with one of the anchoring portions 19 along the given axis A. Each anchoring portion 19 or 20 has two threaded holes 21 to be engaged by screws 22.
Each clamp 15 comprises a base 23, which, in use is parallel to the longitudinal axis A; two wings 24 and 25 configured for being connected, respectively, to the end walls 6 and 7; and a third wing 26 configured for mounting the heat exchanger 1 to the support structure 16 (Figure 2). In the example shown herein, each clamp 15 is made by folding a metal sheet blank, wherein the wings 24 and 26 are end wings bent at a right angle with respect to the base 23 about respective bending lines 27 and 28, while the wing 25 is partly sheared from the base 23, except for a bending line 29 parallel to the bending lines 27 and 28, and subsequently bent at a right angle about the bending line 29.
The wing 25 has a length, measured parallel to the bending lines 27, 28 and 29, shorter than the length of the wing 24, which has a length shorter than the length of the wing 26.
The wing 24 comprises two holes for the fixing, through screws 22, to the anchoring portion 19. With reference to Figure 2, the wing 25 comprises two holes 31 for the fixing to the anchoring portion 20, while the wing 26 has two holes 32 for the fixing to the structure 16. Furthermore, as shown in Figure 3, the wing 26 has openings 33 aligned with the holes 30 and openings 34 aligned with the holes 31, so as to allow the screws 22 to be screwed and unscrewed.
Finally, it is clear that the invention described herein can be subjected to changes and variations, without for this reason going beyond the scope of protection of the appended claims.

Claims

A heat exchanger for a domestic boiler or a water heater, the heat exchanger (1) comprising a casing (2), which comprises a lateral wall (5) extending about a longitudinal axis (A) and a first and a second end wall (6, 7) coupled, on opposite sides, to the lateral wall (5); a tubular member (3), which is configured for conveying water, and is housed in the casing (2); and two clamps (15), each of which is arranged outside the casing (2) and is connected to the first and the second end wall (6, 7) so as to clamp the lateral wall (5) between the first and second end wall (6, 7); the heat exchanger being characterized in that each clamp is configured for being mounted on a support structure (16) so as to fix the heat exchanger (1) to the support structure (16).
The heat exchanger as claimed in Claim 1, wherein the first and the second end wall (6, 7) have respective annular grooves (17, 18) configured for housing, respectively, the opposite edges of the lateral wall (5).
The heat exchanger as claimed in Claim 1 or 2, wherein each clamp (15) is sized so as the first and the second end wall (6, 7) exert a compression force along the longitudinal axis (A) on the lateral wall (5).
The heat exchanger as claimed in any one of the foregoing Claims, wherein the first end wall (6) has two first anchoring portions (19) and the second end wall (7) has two second anchoring portions (20), each of which is aligned to a respective first anchoring portion (19) in a direction parallel to the longitudinal axis (A).
The heat exchanger as claimed in any one of the foregoing Claims, wherein each clamp (15) comprises a base (23); a first and a second wing (24, 25) configured for being connected to the first and second end wall (6, 7); and a third wing (26) configured for mounting the heat exchanger (1) to the support structure (16).
The heat exchanger as claimed in Claim 5, wherein each clamp (15) is made by folding a metal sheet blank, wherein the first and the third wing (24, 26) are end wings bent at right angle with respect to the base (23) about respective bending lines (27, 28), while the second wing (25) is sheared, partly, from the base (23) and bent with respect to the base (23) about a further bend line (29).
The heat exchanger as claimed in Claim 6, wherein the base (23) is parallel to the longitudinal axis (A), while the bend lines (27, 28) and the further bend line (29) are parallel to each other and transversal to the longitudinal axis (A).
The heat exchanger as claimed in any one of the Claims from 5 to 7, wherein the first wing (24) has a length longer than the length of the second wing (25) and shorter than the length of the third wing (26).
The heat exchanger as claimed in any one of the Claims from 5 to 8, wherein the first and the second wing (24, 25) are provided with respective holes (30, 31) for the fixing by means of screws (22), while the third wing (26) is provided with openings (33, 34) each of which is aligned to a respective hole (30, 31) of the first or the second wing (24, 25).