Condensing heat exchanger

Abstract

The present invention relates to a condensing heat exchanger comprising at least one spiral coil tube through which a fluid to be heated can circulate, a deflector, and a shell in which the tube is mounted. The shell is provided with a gas discharge sleeve, a bottom, and a front supporting means for supplying and / or generating a high-temperature gas inside the shell. The exchanger is notable in that the shell comprises a tubular metal cover that is closed at both ends by the front and the bottom, the bottom being made of composite plastic, the rear edge of the cover having a plurality of fastening tongues, the bottom having a plurality of fastening slots arranged along at least a portion of its perimeter, each fastening slot being longitudinally bounded by a first longitudinal rib protruding outward, and each fastening tongue being inserted into the fastening slot and folded twice around the first rib.

Description

Technology Field

[0001] The present invention is in the field of condensation heat exchangers.

[0002] The present invention relates more specifically to a casing structure of such an exchange. Background Technology

[0003] In order to bring condensing heat exchangers to market at a low cost, it is necessary to re-examine the overall structure of existing heat exchangers and, in particular, reduce the number of parts to lower their manufacturing and assembly costs.

[0004] For example, from Document W02004 / 036121, a condensation heat exchanger is known comprising at least one bundle of helically wound tubes made of a thermally conductive material through which water to be heated is passed. The tubes themselves are placed inside a casing, and a burner is axially placed inside a turn, so that the high-temperature gas generated by the burner passes through the space between adjacent turns and heats the water flowing inside the tubes.

[0005] The casing is made of heat-resistant plastic material.

[0006] However, in order to limit the spacing of the tube windings in the axial direction (such movement is caused by the internal pressure of the water flowing within the tube), it is necessary to have retaining plates at each end of the windings and the axial mechanical restraint tie rods. This prevents thrust caused by this pressure from being transmitted to the casing.

[0007] In addition, the plastic casing has the shape of two half-shells assembled together by welding, screws, or clips, and a ferrule is placed between the tube and the inside of the plastic casing to ensure a thermal shielding function that can insulate the casing from heat emitted by flue gas.

[0008] Therefore, such high-performance exchangers contain many parts, making them more expensive and time-consuming to manufacture.

[0009] From document WO2015 / 140664, a heat exchanger is already known that includes a casing in which a spirally wound tube is mounted and water can flow inside, a facade supporting a burner, and a separating element supporting a disc of refractory material.

[0010] Before assembly, the casing includes two half-shells, each half-shell including an integral semi-cylindrical part with a semicircular portion.

[0011] The assembly of the two half-shells is performed by welding along their respective three straight sides.

[0012] The above document does not describe or suggest having a casing composed of a tubular metal ferrule and a bottom formed of a composite plastic material before assembly, nor does it describe or suggest the assembly of these two elements through the cooperation of a tab and a slot.

[0013] Consequently, the two half-shells must be made of very thick material that possesses both excellent mechanical resistance and excellent thermal resistance to resist high-temperature gases and ensure tube compression. Therefore, such heat exchangers are implemented with more expensive materials.

[0014] Accordingly, one objective of the present invention is to propose a reliable exchanger in which the casing is not deformed, while limiting the total number of parts of a condensing heat exchanger, simplifying the assembly of these parts, and finally eliminating axial stress tie rods.

[0015] Another objective of the present invention is to manufacture a heat exchanger that is cheaper than heat exchangers known from the latest technology while ensuring the axial stress function of the wound tube.

[0016] Therefore, it was necessary to completely redesign such a heat exchanger.

[0017] To this end, the present invention:

[0018] - At least one spirally wound tube made of a thermally conductive material through which a fluid to be heated, such as water, can flow,

[0019] - A casing in which the above-mentioned tube is mounted internally, wherein the casing is provided with a front supporting a means for delivering and / or generating high-temperature gas inside the casing, such as a gas discharge sleeve, a bottom, and a gas or oil burner;

[0020] - The invention relates to a condensation heat exchanger comprising a deflector including a disc made of insulating material supported by sheet metal reinforcement, wherein the deflector is positioned relative to a spirally wound tube to partition a combustion chamber together with the front.

[0021] According to the present invention, the casing comprises a body composed of a tubular metal ferrule, the tubular ferrule being closed by the front at one of two ends and by the bottom at the other end, the tubular ferrule and the bottom being separated before assembly, the bottom being formed of a composite plastic material, one of the two edges of the tubular ferrule called the "rear edge" having a plurality of cutouts separating fastening tabs on at least a portion of its circumference, the bottom having a plurality of fastening slots arranged along at least a portion of its circumference on its periphery, each fastening slot being dimensioned so that a fastening tab can be inserted inside, each fastening slot being longitudinally bounded by a first longitudinal rib protruding outwardly, the fastening tab being folded twice around the first rib so that the ferrule is fastened to the bottom and the spiral tube winding is subjected to axial stress at two ends between the bottom and the front.

[0022] Thanks to these features of the present invention, tie rods are eliminated, the total number of parts is reduced, and costs are lowered; however, the double folding of the tab prevents the spirally wound tube from expanding axially because the attachment of the bottom and ferrule is sufficient to prevent any deformation of the casing. Additionally, the bottom and ferrule are made of different materials that are more suitable for the stresses they receive.

[0023] According to other advantageous and non-limiting features of the present invention taken alone or in combination:

[0024] - The bottom comprises an outer partition, a recess arranged in the outer partition (such recess protrudes outward from the exchanger and opens at the top to a gas discharge sleeve), and an inner partition connecting two faces of the outer partition located on both sides of the recess inlet, wherein the inner partition compartmentalizes the gas discharge channel opened to the gas discharge sleeve with the recess, and the rear edge of the tubular ferrule has a plurality of cutouts compartmentalizing a fastening tab along its entire circumference, a fastening tab along part of its circumference, and at least one attachment tab along the remainder of its circumference, wherein the inner partition is provided with at least one slot for receiving the attachment tab or fastening tab, and the fastening tab or attachment tab inserted into the receiving slot is folded against the inner partition to ensure the fastening of the ferrule to the bottom and to ensure axial stress of the spirally wound tube at one end by the front and at the other end by the outer partition and the inner partition of the bottom;

[0025] - The rear edge of the tubular metal ferrule is provided with a plurality of cutouts partitioning a fastening tab and a plurality of cutouts partitioning at least one attachment tab, and each receiving slot arranged in an internal partition called an attachment slot has dimensions into which an attachment tab can be inserted, such that the attachment tab is folded once against the surface of the internal partition located opposite the gas discharge channel;

[0026] - A recess arranged in an outer bulkhead has a rear wall bounded by two side walls, and a gas exhaust sleeve includes a cover intended to be added to and fastened to the bottom, and such cover includes a return bulkhead, which is partitioned by the inner bulkhead and two side walls, and the gas exhaust channel is opened to the gas exhaust sleeve, and each receiving slot arranged in the inner bulkhead, called a fastening slot, is longitudinally bounded by a first longitudinal rib, and a fastening tab is provided along the entire periphery of the rear edge of the tubular metal ferrule, and the fastening tab is inserted into each fastening slot and folded twice around the first rib;

[0027] - The bottom has a gas discharge channel extending outwardly along the longitudinal axis of the exchanger, and this gas discharge channel is coupled with the gas discharge sleeve, the rear edge of the ferrule has the fastening tab along its entire circumference, and the bottom has the fastening slot that accommodates the fastening tab along its entire circumference;

[0028] - The first longitudinal rib has a square or rectangular cross-section, and the fastening tab is folded twice at a right angle around the protruding ridge of this first longitudinal rib;

[0029] - An adhesive layer is disposed between the inner radial wall of each fastening slot of the attachment slot and / or between the surface of each fastening tab of the attachment tab positioned oppositely thereto;

[0030] - In addition, a second rib is formed on the floor near the first rib to partition the cavity, and the width and depth of the cavity as well as the length of the fastening tab are dimensioned such that the fastening tab is folded three times toward the outside of the exchanger and its free end is supported against the front of the second rib located opposite the first rib;

[0031] - A second rib is formed on the bottom near the first rib to partition the cavity together with it, and a resin layer is arranged in the cavity to cover the end of the fastening tab;

[0032] - The above ferrule is formed from a self-folded and / or bent sheet metal strip and preferably has both ends assembled along a welding line;

[0033] - The above ferrule is made of stainless steel;

[0034] - The reinforcing member of the deflector is inserted between two adjacent windings of the tube and, together with the bottom, defines the condensation chamber;

[0035] - The reinforcing member of the above deflector is inserted between the last winding, called the "rear" winding of the spirally wound tube, and the bottom, and several spacers are placed between the bottom and the reinforcing member to arrange a gas flow space connected to the gas discharge sleeve between the bottom and the reinforcing member. Brief explanation of the drawing

[0036] Other features, objects, and advantages of the present invention are purely illustrative and not limiting and will appear in the following description, which should be read in conjunction with the accompanying drawings. FIG. 1 is an overview of different components of a heat exchanger according to the present invention that does not have a burner. FIG. 2 is a perspective view and a front view of the exchanger part of FIG. 1, which has been assembled. FIG. 3 is a perspective view and a rear view of the parts of the exchanger of FIG. 1, once assembled. FIG. 4 is a cross-sectional view of the exchanger of FIG. 2 taken along the cross-sectional plane passing through line IV-IV of FIG. 2, with an added burner. Figure 5 is a cross-sectional view of the exchanger of Figure 2 taken along the cross-sectional plane passing through the VV line of Figure 2, with a burner added. Fig. 6 is a perspective view of the casing. Figure 7 is a perspective view and a plan view of a portion of the floor. FIG. 8 is a perspective and rear view of a part of a switch component showing several fastening tabs of a ferrule engaged in a fastening slot on the bottom. FIG. 9 is a drawing similar to FIG. 8, in which a fastening tab engaged in a fastening slot is folded twice by itself around a first fastening rib. FIG. 10 is a cross-sectional view and a detailed view of a fastening tab of a ferrule that is engaged with a fastening slot on the bottom and folded twice. FIG. 11 is a drawing similar to FIG. 10, in which adhesive is added between the tab and the slot arranged on the bottom. FIG. 12a is a drawing similar to FIG. 10, in which adhesive is applied to the curved portion of the tab on the outer side of the bottom. Fig. 12b shows the two tabs and two slots of Fig. 12a, but it is a plan view. FIG. 13a is a modified example of FIG. 10 in which the fastening tab is folded three times. Figure 13b shows the two tabs and two slots of Figure 13a, but it is a plan view. FIG. 14a is a drawing similar to FIG. 10, in which an adhesive is applied between the first fastening rib and the second fastening rib on the outer side of the bottom. Fig. 14b shows the two tabs and two slots of Fig. 14a, but it is a plan view. FIG. 15 is a cross-sectional view and a detailed view of the attachment tab of a ferrule that is engaged with the attachment slot on the bottom and folded once. FIG. 16 is a drawing showing the tensile force applied to the ferrule when the fastening tab is not retained in the slot. Figure 17 is a diagram showing the result of the traction force applied to the ferrule in the case of Figure 16. FIG. 18 is a cross-sectional view of another embodiment of the exchanger. FIG. 19 is a cross-sectional view of another variation of the exchanger. FIG. 20 is a cross-sectional view illustrating a different arrangement of deflectors. Specific details for implementing the invention

[0037] Referring to the overall drawing of FIG. 1, it can be seen that the condensation heat exchanger (1) according to the present invention comprises a casing (2), at least one tube (3), a deflector (4), and means (5) for delivering or generating high-temperature gas, the latter of which can be seen only in FIG. 4 and FIG. 5.

[0038] The casing (2) includes a tubular ferrule (6), a front (7), and a bottom (8) that form the main body of the casing. The front (7) supports the means (5) for delivering or generating high-temperature gas, as described below. Additionally, as can be seen in FIG. 1, the tubular ferrule (6) and the bottom (8) are separated before their assembly, which will be described below.

[0039] FIGS. 1 through 4 show an enclosure (1) in a normal use position. Accordingly, the terms “upper” or “lower” in the remainder of the description and claims should be considered in relation to this normal use position.

[0040] The tube (3) is wound spirally on itself to form a spiral winding having a longitudinal axis (XX'). The tube (3) has two ends forming an inlet mouse (31) and an outlet mouse (32).

[0041] The tube is made of thermally conductive materials, particularly metals, advantageously stainless steel. It is intended to accommodate a fluid to be heated, such as water.

[0042] As can be seen in FIGS. 4 and 5, there is a gap (33) of a constant or substantially constant correction value between two adjacent windings of the tube (3). Note that in these drawings, the tube (3) has a flat and elliptical cross section, but any other section may be presented.

[0043] The tube (3) is intended to be mounted inside the casing (2), and the components of the casing will now be described in more detail. Although not shown, it is also possible to have multiple tubes (3) wound spirally in the casing (2), and these windings are coaxial.

[0044] The tubular ferrule (6) is advantageously made of sheet metal strip, preferably stainless steel. Advantageously, such sheet has a thickness of 1 mm or less.

[0045] These sheet metal strips advantageously have a central portion called a "base wall" (60). This base wall (60) is slightly inclined toward its center so that condensate can be discharged by gravity through an outlet orifice (601) connected to a condensate discharge duct (602).

[0046] Two openings (603, 604) are provided in the base wall (60). When the tube (3) is mounted inside the ferrule (6), its inlet mouth (31) and outlet mouth (32) are each compressed and / or welded in an airtight manner within the aforementioned openings (603 and 604).

[0047] Advantageously, two ends of the sheet metal strips located on both sides of the base wall (60) are folded substantially perpendicular to the base wall (60) and then curved, and their two free ends are welded along the welding line (605).

[0048] The tubular ferrule (6) formed in this way has a front edge (606) and an opposite rear edge (607).

[0049] The front (7) has a rim (70) around it that is sealed, preferably welded, to the front edge (606) of the annular ferrule (6).

[0050] The front (7) is provided with several, in this case four, studs (71) protruding outward from the exchanger (1). The front (7) includes a central opening (72) that can be blocked by a door (73), the latter of which is visible only in FIGS. 4 and FIGS. 5.

[0051] The door (73) is fastened to the front (7) by a stud (71). The door (73) supports a burner (50) in its central portion, for example, a gas or oil burner constituting an exemplary embodiment of a means for generating high-temperature gas (5). This burner may be replaced by a means for delivering high-temperature gas (e.g., a fan), and this high-temperature gas is generated outside the enclosure (casing).

[0052] The door (73) may be attached differently to the front (7).

[0053] As can be best seen in FIG. 6, which illustrates a first embodiment of the ferrule (6), the rear edge (607) has a plurality of cutouts around it that partition a series of first tabs (hereinafter referred to as "fastening tabs" (61)) and at least one other tab, hereinafter referred to as "attachment tabs" (62), in order to distinguish the fastening mode at the bottom (8). The tabs (61) are separated from each other by cutouts (notches) (63) and the tabs (62) are separated by cutouts (notches) (64).

[0054] A fastening tab (61) is formed on almost the entire edge (607), except for the upper curve of this edge, that is, the portion located on both sides of the welding line (605) in the exemplary embodiment shown in the drawing. An attachment tab (62) is formed on this upper curve of the edge (607).

[0055] Advantageously, a cutout is made so that the fastening tab (61) and the attachment tab (62) have a rectangular shape. Additionally, preferably, a cutout is made so that the attachment tab (62) is recessed from the fastening tab (61). In other words, the length (L1) between the front edge (606) and the free end of the fastening tab (61) is greater than the length (L2) between the front edge (606) and the free end of the attachment tab (62). The role of this offset will be explained later.

[0056] The bottom (8) is made of a composite plastic material. Such a plastic material comprises at least two different components. As an exemplary example, such a composite plastic material may be fiber-filled polypropylene, in particular glass fiber-filled polypropylene.

[0057] As can be best seen in the cross-sectional views of FIGS. 4, 5 and 7 illustrating a first embodiment of the floor (8), such floor (8) includes a partition called an “external” partition (80), which is flat except for a central area forming a recess (801) protruding outward and a perimeter area forming a perimeter rim (802) also protruding outward.

[0058] The contour of the outer bulkhead (80) substantially corresponds to the contour of the rear edge (607) of the ferrule (6). That is, this contour has a roughly square shape with a rounded top surface.

[0059] The concave portion (801) has a U-shaped contour that opens upward from the bottom (8). The concave portion (801) includes a rear wall (8010) and two side walls (8011) that define the depth of the concave portion (801) (see FIG. 3).

[0060] Additionally, in the upper part of the bottom (8), a partition section called an "internal partition" (81) combines the two sides of the external partition (80) located on both sides of the mouse of the concave part (801) with the two side walls (8011) of the external partition (80) located on both sides of the mouse of the concave part (801). As can be seen in FIG. 1, this internal partition (81) advantageously has an arc shape to match the shape of the spiral winding of the tube (3).

[0061] As can be seen in FIGS. 4 and 7, the inner partition (81) extends a certain distance from the recess (801) and arranges a channel (82) for collecting and discharging gas together with the latter. A spacer (83) may be provided between the inner partition (81) and the recess (801), as can be seen in FIGS. 1 and 7.

[0062] Additionally, the internal bulkhead (81) extends forward of the exchanger (i.e., toward the front (7) and axially) by a curved wall (84) having a recess that matches the contour of the arc-shaped upper portion of the ferrule (6). A vertical rim (85) surrounds the curved wall (84) to define the lower portion of the gas exhaust sleeve (86). Finally, a cover (87) constituting the upper portion of the gas exhaust sleeve (86) covers the rim (85). This cover (87) is sealedly joined to this rim (85). The cover (87) is provided with an exhaust opening (870), preferably located in its upper portion. This opening (870), provided with a gasket (871), allows for a connection to a gas exhaust pipe not shown in the drawing.

[0063] Advantageously, as best seen in FIGS. 2 and 3, the outer bulkhead (80) may be extended by, for example, three lugs, each provided with a lug (804), wherein a fastening orifice (8040) is provided, the latter allowing the bottom (8) to be fastened to the bulkhead of the boiler, which is not shown in the drawing. These orifices (8040) allow, for example, the passage of a fastening screw. Finally, advantageously, a reinforcing rib (805) may be provided on the outer surface and / or bottom surface of the outer bulkhead (80).

[0064] The fastening of the ferrule (6) on the floor (8) will now be explained in more detail.

[0065] The outer bulkhead (80) is provided with a series of slots (806), referred to as “fastening slots,” formed in a protruding rim (802) around it. These slots (806) are arranged end-to-end in a circumferential manner from the bottom (8). These slots (806) extend all around the outer bulkhead (80), except for the upper portion where the recess (801) is open. These fastening slots (806) are dimensioned to accommodate fastening tabs (61), as best illustrated in FIGS. 8 through 14b.

[0066] Referring to FIGS. 8 through 10, it can be seen how the fastening tab (61) is assembled into the fastening slot (806). Each fastening slot (806) includes an inner wall (8061) and an outer wall (8062) along the radial direction of the exchanger (see FIG. 10).

[0067] Each fastening slot (806) is bounded by a first longitudinal rib (807) protruding outward from the outer bulkhead (80), more specifically from the rim (802) of the outer bulkhead. This first rib (807) is preferably located near the inner radial wall (8061) of the slot.

[0068] Preferably, this first rib (807) has a cross-section that is square or rectangular in shape.

[0069] As shown in FIG. 8, the fastening tab (61) is introduced into the fastening slot (806) and then folded by two crimping operations around the first longitudinal rib (807).

[0070] As can be seen in FIGS. 8 and 9, the ferrule (6) is closer to the bottom (8), and accordingly, all fastening tabs (61) are passed through each fastening slot (806) located on the opposite side.

[0071] If the first longitudinal rib (807) has a square or rectangular cross-section, the fastening tab (61) is folded twice at a right angle, that is, once in the radial direction of the exchanger and twice in the axial direction.

[0072] As can be seen in FIG. 4, when the fastening tab (61) is crimped, the outer bulkhead (80) is placed against the last winding of the tube (3) located at the rear of the exchanger, and the front (7) is placed against the first winding of the tube (3) located at the front of the exchanger.

[0073] This enables axial compression of the tube (3).

[0074] Finally, as can be seen in the lower part of FIG. 5, the bottom of the notch (63) comes into contact with the inner surface of the protruding rim (802).

[0075] FIG. 11 illustrates a modified example in which an adhesive layer (90) is applied to the inner surface of a fastening tab (61) before being introduced into the fastening slot (806), and thus the adhesive layer (90) is distributed between the tab (61) and the radial inner wall (8061) of the slot (806) to strengthen the fastening of the fastening tab (61) and strengthen the fastening of the ferrule (6) on the bottom (8).

[0076] It is also possible to provide an adhesive layer (90) between the tab (61) and the radial outer wall (8062) of the slot, but it should be noted that this is not shown in FIG. 11.

[0077] This adhesive layer (90) enhances the airtightness of the casing (2). For example, silicone adhesive may be used.

[0078] FIGS. 12a and 12b illustrate other variations in which a resin layer (91) is applied to the end of a fastening tab (61) on the outer side of a partition (80). Accordingly, to facilitate the retention of this resin layer (91), a second longitudinal rib (808) is arranged opposite the first longitudinal rib (807) to partition together a cavity (809) in which the resin (91) can accumulate.

[0079] These resins (91) have the function of strengthening the fastening of the fastening tabs (61) around the first rib (807) and preventing these tabs from spreading out.

[0080] In addition, it is also possible to combine the addition of adhesive (90) and resin (91).

[0081] FIGS. 13a and 13b show a modified example in which the fastening tab (61) is slightly longer than before so that it can be folded three times outward from the exchanger. In this case, the end of the fastening tab is folded into a V shape inside the cavity (809), and the two branches of the V shape, which tend to separate from each other due to elasticity, have the effect of reinforcing the blockage of the tab (61) in the cavity (809) and preventing the tab from coming out of the fastening slot (806) when the dominant pressure inside the tube (3) tends to separate the winding of the tube axially.

[0082] Although not shown in FIG. 13a and FIG. 13b, it is also possible to cover the end of the tab (61) as previously described in relation to FIG. 11 to FIG. 12b by providing an adhesive layer (90) between one of the walls (8061, 8062) of the fastening tab (61) and the slot (806) and / or adding a resin layer (91) into the cavity (809).

[0083] FIGS. 14a and FIGS. 14b show other simplified variations of FIGS. 12a and FIGS. 12b, where the resin layer (91) is applied only inside the cavity (809) and thus only to the end of the tab (61).

[0084] FIG. 15 illustrates a method in which an attachment tab (62) is assembled with a slot called an "attachment" slot (810) arranged in an inner partition (81). There are as many attachment slots (810) as there are tabs (62). In this case, the end of the attachment tab (62) is folded radially only once in the exchanger and pressed against a surface of the inner partition (81) located on the opposite side of the gas discharge channel (82), preferably in the radially inward direction.

[0085] Advantageously, the adhesive layer (90) may also be deposited between the inner radial wall (8101) of the attachment tab (62) and the slot (810) and / or between the outer radial wall (8102) of the attachment tab (62) and the slot (810).

[0086] In fact, the cover (87) of the gas discharge sleeve is not fastened unless the attachment tab (62) is crimped during the manufacturing process. As can be understood by examining FIG. 4, the absence of this cover can be achieved by introducing a crimping tool into the channel (82) opposite the tab (62).

[0087] In this position, the winding of the tube (3) is subjected to axial stress between the front (7) and the inner bulkhead (81).

[0088] Additionally, as mentioned above, the attachment tab (62) is retracted from the fastening tab (61). In fact, as can be seen in FIG. 4, when the last rear winding of the tube (3) ends at the inlet mouth (31) and the latter passes through the opening (603) arranged in the ferrule (6), the fastening tab (61) is advantageously crimped to the protruding rim (802) of the bottom (8) (i.e., not directly aligned with the outer wall (80) but outwardly, i.e., slightly offset toward the left in FIG. 4) so ​​as to retain sufficient material of the ferrule (6) between the opening (603) and the fastening tab (61) and not weaken the ferrule in this position. Meanwhile, the attachment tab (62) is fastened to the inner bulkhead (81) which is retracted from the rim (802).

[0089] FIG. 18 shows another variation of the present invention in which the gas discharge sleeve (86) and the concave portion (801) are shaped differently so as to have a ferrule (6) having a fastening tab (61) along its entire periphery.

[0090] More specifically, in this case, the rear wall (8010) of the recess (801) does not extend to the top of the bottom (8), and the cover (87) includes a return partition (872) that extends in the direction of the recess (801) in the opposite direction of the inner partition (81) and together partitions the gas discharge channel (82). The joint line between the return partition (872) and the top of the recess (801) is referred to by reference numeral 89. At both ends, the inner partition (81) is fixed to the side wall (8011).

[0091] The internal bulkhead (81) includes at least one fastening slot (806') that is longitudinally bounded by the first rib (807') (as previously described) and the cavity (809'), respectively. Each fastening tab (61) is folded twice around the rib (807').

[0092] When crimping the fastening tab (61), it is possible to fold the fastening tab (61) twice because the cover (87) is absent and the internal partition (81) is more accessible. A resin layer (91) can also be deposited on the tab (61).

[0093] It is easy to understand that the bottom (8) and the gas discharge sleeve may have different shapes, and depending on the position of the gas discharge channel (82) relative to the bottom (8), the previously described fastening slot (806) may be provided on a part of the perimeter of the bottom (8) or on its entire perimeter. This latter possibility may apply, for example, when the gas discharge channel (82) extends outward from the bottom (8) along the longitudinal axis (XX') of the exchanger (see FIG. 19) before the gas discharge sleeve (86) is joined. The last rear winding of the tube (3) is placed on the outer bulkhead (80) and axial compression is ensured.

[0094] A test was performed to measure the tensile strength applied to the ferrule (6) when the tube (3) is deformed in the axial direction and pushes the bottom (8).

[0095] FIGS. 16 and 17 schematically illustrate a situation that would be observed if the fastening tab (61) were simply crimped around the longitudinal rib (807) and did not pass through the fastening slot (806). In this case, it should be noted that a traction force is applied to the casing (6) along the axial direction and the direction of the arrow (G), and if this traction force exceeds a certain threshold, the tab (61) tends to deform and spread out so that it no longer serves to fasten the casing (6) and the bottom (8).

[0096] Therefore, the test showed that the fastening tab (61) could withstand a tensile strength of 65 kg before deformation in the case shown in FIG. 16, where the tab (61) does not engage with the slot.

[0097] As shown in FIG. 10, when the fastening tab (61) engages with the fastening slot, the test showed that the tab could withstand a tensile strength of 110 kg before deformation. Finally, as shown in FIG. 13a, a test performed with the fastening tab folded three times showed that the tab could withstand a tensile strength of 140 kg.

[0098] The deflection device (4) includes a disc (41) made of insulating material, which is supported by a reinforcing material made of a thin sheet metal (42).

[0099] These deflectors (4) can always be positioned in two different ways relative to the tube (3) to form at least one combustion chamber (11).

[0100] According to the first embodiment illustrated in FIG. 4, a deflector (4) is inserted into the tube (3) such that the peripheral edge of the reinforcing material (42) is inserted between two adjacent windings of the tube (3). Thus, this deflector (4) defines a combustion chamber (11) arranged between this deflector and the front (7) and a condensation chamber (12) arranged between this deflector and the bottom (8).

[0101] According to the second embodiment illustrated in FIG. 20, the deflector (4) is positioned between the bottom (8) and the last winding (i.e., the winding located near the bottom (8)) referred to as the "rear" winding of the tube (3). In this case, the deflector (4) limits only the combustion chamber (11) extending between this deflector and the front (7). In this case, a plurality of spacers (88) are positioned between the bottom (8) and the reinforcing member (42) to arrange a gas flow space (880) connected to the gas discharge sleeve (86) through a gas discharge channel (82) between these two elements.

[0102] Advantageously, the spacers (88) are arranged on the surface facing forward (toward the front (7)) of the outer bulkhead (80) and the inner bulkhead (81).

[0103] The assembly of different elements of the exchanger (1) can be performed, for example, as follows.

[0104] The tube (3) provided with the deflector (4) is inserted into the ferrule (6) before or after the strip constituting it is closed and welded (605) is made. The mouse (31, 32) is compressed and / or welded in a hermetic manner at the orifice (603, 604).

[0105] The front (7) is welded to the front edge (606) of the casing (6). The casing (6) is brought closer to the bottom (8), so that the fastening tab (61) enters the fastening slot (806) and the attachment tab (62) (when these are present) enters the bottom (8) of the attachment slot (810).

[0106] The crimping of the different taps (61, 62) is performed as previously described.

[0107] Finally, the cover (87) of the gas discharge sleeve (86) is fastened to the rim (85) of the bottom (8).

[0108] The operation of the condensation heat exchanger (1) obtained in this way will be briefly recalled below.

[0109] Inside the combustion chamber (11), the high-temperature gas generated by the burner (50) passes through the gap (33) existing between adjacent windings of the tube (3), collides with the ferrule (6) from the inside to the outside, continues in the condensation chamber (12), passes through the gap (33) existing between adjacent windings of the tube (3) again, this time from the outside to the inside, and is then discharged through the discharge channel (82) and the gas discharge sleeve (86).

[0110] In the embodiment shown in FIG. 20, the high-temperature gas generated by the burner (50) passes from the inside to the outside through the gap (33) existing between adjacent windings of the tube (3), collides with the ferrule (6), passes through the gas flow space (880), and is then discharged through the discharge channel (82) and the gas discharge sleeve (86) (see arrow (i)).

[0111] Additionally, the fluid to be heated flows from the inlet mouse (31) to the outlet mouse (32), that is, in reverse flow against the high-temperature gas.

[0112] Therefore, the exchanger according to the present invention has many advantages. Compared to the exchanger of the latest technology, the total number of parts is reduced, and the tie rod is eliminated while applying axial stress to the winding of the tube (3). Installation is simple.

[0113] In addition, the bottom (8) is compact and incorporates a gas discharge sleeve, thereby ensuring the function of gas discharge at the bottom of the enclosure and participating in the axial stress of the tube (3) winding.

[0114] Finally, the bottom (8) is not subjected to a temperature load due to the presence of the deflector (4). It is made of a composite plastic material advantageously selected to resist mechanical stress received by the bottom (8) when there is an axial spacing of the tube (3) windings. This material can avoid any risk of electrolysis as the material of the ferrule (6). Thus, the entire exchanger is lower than the latest technology exchanger while ensuring axial stress of the tube (3) windings thanks to the innovative fastening mode of the ferrule (6) and the bottom (8).

Claims

Claim 1 - at least one helically wound tube (3) made of a thermally conductive material and through which a fluid to be heated, such as water, can flow; - a casing (2) in which the helically wound tube (3) is mounted internally, wherein the casing (2) is provided with a facade (7) supporting means for delivering and / or generating high-temperature gas inside the casing, such as a gas discharge sleeve (86), a bottom (8), and a gas or oil burner (50); - a deflector (4) comprising a disc (41) made of an insulating material supported by sheet metal reinforcement (42), wherein the deflector (4) is positioned relative to the helically wound tube (3) to partition a combustion chamber (11) together with the facade (7), wherein the casing (2) comprises a tubular metal ferrule (ferrule; 6) comprising a main body, wherein the tubular metal ferrule (6) is closed by the front (7) at one of its two ends and by the bottom (8) at the other end, the tubular metal ferrule (6) and the bottom (8) are separated before assembly, the bottom (8) is formed of a composite plastic material, and one of the two edges of the tubular metal ferrule, called the rear edge (607), has a plurality of cutouts (63) that partition a fastening tab (61) on at least part of its circumference, and the bottom (8) has a plurality of fastening slots (806) arranged along at least part of its circumference on its periphery, each fastening slot (806) is dimensioned so that a fastening tab (61) can be inserted into its interior, and each fastening slot (806) has a first longitudinal rib (rib;A condensation heat exchanger (1) characterized by being longitudinally bounded by 807), wherein the fastening tab (61) is folded twice around the first rib (807), so that a tubular metal ferrule (6) is fastened to the bottom (8) and the spirally wound tube (3) receives axial stress at its two ends between the bottom (8) and the front (7). Claim 2 In claim 1, the bottom (8) comprises: - an outer partition (80), - a recess (801) arranged in the outer partition, wherein the recess (801) protrudes outward from the exchanger and opens into the gas discharge sleeve (86) at its upper portion, and - an inner partition (81) that combines the two sides of the outer partition (80) located on both sides of the recess (801) and partitions the gas discharge channel (82) that opens into the gas discharge sleeve (86) into the recess (801); and the rear edge (607) of the tubular metal ferrule (6) has a plurality of cutouts (63, 64) that partition a fastening tab (61) along its entire circumference or a fastening tab (61) along part of its circumference and at least one attachment tab (62) along the remainder of its circumference, and such inner A condensation heat exchanger (1), wherein the bulkhead (81) is provided with at least one slot (810, 806') for receiving an attachment tab (62) or a fastening tab (61), and the fastening tab (61) or attachment tab (62) inserted into the receiving slot (810, 806') is folded against the inner bulkhead (81) to ensure fastening of the tubular metal ferrule (6) to the bottom (8) and to ensure axial stress of the spirally wound tube (3) by the front (7) at one of its ends and by the outer bulkhead (80) and the inner bulkhead (81) of the bottom (8) at the other end. Claim 3 In claim 2, the rear edge (607) of the tubular metal ferrule (6) is provided with a plurality of cutouts (63) partitioning a fastening tab (61) and a plurality of cutouts (64) partitioning at least one attachment tab (62), and each receiving slot arranged in the inner bulkhead (81), called an attachment slot (810), is sized such that an attachment tab (62) can be inserted therein, and such attachment tab (62) is folded once against the face of the inner bulkhead (81) located opposite the gas discharge channel (82), the condensation heat exchanger (1). Claim 4 In claim 2, the recess (801) arranged in the outer bulkhead (80) has a rear wall (8010) bordered by two side walls (8011), the gas exhaust sleeve (86) includes a cover (87) intended to be added to and fastened to the bottom (8), the cover (87) includes a return bulkhead (872), the return bulkhead (872) partitions the gas exhaust channel (82) open into the gas exhaust sleeve by the inner bulkhead (81) and the two side walls (8011), each receiving slot arranged in the inner bulkhead (81), called a fastening slot (806'), is longitudinally bordered by a first longitudinal rib (807'), and a fastening tab (61) is provided along the entire periphery of the rear edge (607) of the tubular metal ferrule (6), and the fastening tab (61) is each fastening A condensation heat exchanger (1) characterized by being inserted into a slot (806') and folded twice around the first rib (807'). Claim 5 A condensation heat exchanger (1), characterized in that, in claim 1, the bottom (8) has a gas discharge channel (82) extending outwardly along the longitudinal direction (XX') of the exchanger, and the gas discharge channel (82) connects to the gas discharge sleeve (86), the rear edge (607) of the tubular metal ferrule (6) has the fastening tab (61) along its entire circumference, and the bottom (8) has the fastening slot (806) that accommodates the fastening tab (61) along its entire circumference. Claim 6 A condensation heat exchanger (1), characterized in that, in any one of claims 1 to 5, the first longitudinal rib (807) has a square or rectangular cross-section, and the fastening tab (61) is folded twice at a right angle around the protruding ridge of the first longitudinal rib. Claim 7 A condensation heat exchanger (1), wherein, in any one of claims 1 to 5, the adhesive layer is disposed between the inner radial wall (8061, 8101) of each fastening slot (806) of the attachment slot (810) and the surface of each fastening tab (61) of the oppositely positioned attachment tab (62), and / or the adhesive layer (90) is disposed between the outer radial wall (8062, 8102) of each fastening slot (806) of the attachment slot (810) and the surface of each fastening tab (61) of the oppositely positioned attachment tab (62). Claim 8 A condensation heat exchanger (1), characterized in that, in any one of claims 1 to 5, a second rib (808) is formed on the bottom (80) near the first rib (807) to partition the cavity (809), and the width and depth of the cavity (809), as well as the length of the fastening tab (61), are dimensioned such that the fastening tab (61) is folded three times toward the outside of the exchanger and its free end is supported against the surface of the second rib (808) located opposite the first rib (807). Claim 9 A condensation heat exchanger (1) characterized in that, in any one of claims 1 to 5, a second rib (808) is formed in the bottom (80) near the first rib (807) to partition the cavity (809) together with it, and a resin layer (91) is arranged in the cavity (809) to cover the end of the fastening tab (61). Claim 10 A condensation heat exchanger (1), characterized in that, in any one of claims 1 to 5, the tubular metal ferrule (6) is formed from a self-folded and / or bent sheet metal strip and both ends thereof are assembled. Claim 11 A condensation heat exchanger (1), characterized in that, in any one of claims 1 to 5, the tubular metal ferrule (6) is made of stainless steel. Claim 12 A condensation heat exchanger (1), characterized in that, in any one of claims 1 to 5, the reinforcing member (42) of the deflector (4) is inserted between two adjacent turns of a spirally wound tube (3) and together with the bottom (8) defines a condensation chamber (12). Claim 13 A condensation heat exchanger (1), characterized in that, in any one of claims 1 to 5, the reinforcing member (42) of the deflector (4) is inserted between the last winding, called the "rear" winding of the spirally wound tube (3), and the bottom (8), and several spacers (88) are placed between the bottom (8) and the reinforcing member (42) to arrange a gas flow space (880) connected to the gas discharge sleeve (86) between the bottom and the reinforcing member.

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