EP0544849A1

EP0544849A1 - Doubble-walled heating duct of a heat water device.

Info

Publication number: EP0544849A1
Application number: EP92909733A
Authority: EP
Inventors: Klaus Geil; Dirk Haibach; Peter Menne; Wilfried Niether; Rainer Schild; Johann Wienen; Wilhem Wingensiefen
Original assignee: Joh Vaillant GmbH and Co
Current assignee: Nv Vaillant Sa; VAILLANT B.V.; Vaillant Austria GmbH; Vaillant GmbH; Vaillant SARL; Vaillant Ltd
Priority date: 1991-05-21
Filing date: 1992-05-15
Publication date: 1993-06-09
Anticipated expiration: 2012-05-15
Also published as: EP0544849B1; ATE121831T1; WO1992020976A1; DE59202027D1; DE4216474A1

Abstract

Process for producing a double-walled heating duct (1) of a burner-heated hot-water generator in which the inner and outer casings (2 and 3) of the heating duct (1) are closely joined at the edge regions and said duct (1) is fitted with connecting pipes for the supply and discharge of a heating medium flowing through it. To enable such a heating duct to be easily produced, only shaping process are used and the inner and outer casings (2, 3) have edge recesses cut in them which are put together in their edge regions with the interposition of a seal, preferably a toroidal sealing ring (10), and then secured together by bending so as to provide mutual engagement.

Description

"Process for producing a double-walled heating shaft"

The invention relates to a method for producing a double-walled heating shaft of a burner-heated hot water device, in which the inner and outer shells are tightly connected to one another in edge areas and which has connecting pipes for the supply and discharge of one of the Heating shaft flowing through the heating medium is provided in accordance with the preambles of the secondary claims 1, 8 and 10.

According to the known methods for producing double-walled heating shafts, the jackets are first deformed in order to create a certain clear space between the jackets. The jackets are then tightly connected to one another in the edge zones.

This requires a high manufacturing effort. In addition, it turns out in the case of the conventionally produced heating ducts that they are not particularly pressure-resistant and that an undesired deformation of the jackets of the heating duct can occur when the test pressure is applied.

To connect, the outer and inner shells are welded together. The connecting pipes are also connected to the outer jacket by welds. A disadvantage of this, in addition to a relatively complex manufacture, is that when choosing the material for the jackets and the connecting pipes, their weldability must be taken into account. Difficulties also arise from the fact that the transition arches must be separated from the areas in which the inner jacket is spaced from the outer jacket by areas in which the outer and inner jackets are sealed against one another.

The aim of the invention is to propose a method which enables simple manufacture of a heating shaft. In particular, sufficient sealing of the transition arches against the areas delimiting an essentially continuous cavity is to be ensured.

Furthermore, a high degree of pressure resistance and dimensional stability of the double jacket heating shaft must be guaranteed.

According to the invention this is achieved by the characterizing features of claims 1, 8 and 10.

These measures make it possible to manufacture the heating shaft simply by deforming metal sheets. As a result, the choice of material can be made solely on the basis of corrosion resistance and good deformability. In addition, there is the advantage that the widening of the interior of the heating shaft is already anticipated during the manufacture by the application of a correspondingly high pressure to the space between the two jackets of the heating shaft Subsequent application of the intended test pressure cannot lead to further deformation of the heating shaft.

Advantageous developments of the invention are characterized in the subclaims or are explained in more detail below together with the description of the preferred embodiment of the invention with reference to the drawing.

Show:

FIG. 1 schematically shows a section of a heating shaft during an intermediate stage of the process,

FIGS. 2 and 3 details of the connection of the two jackets of the heating shaft according to FIG. 1,

FIG. 4 shows a detail of the connection of the two jackets of the heating shaft according to a further embodiment,

FIG. 5 shows schematically the connection of a connecting pipe to the heating shaft,

FIG. 6 schematically shows a variant of connecting a connecting pipe to the heating shaft,

FIG. 7 shows a plan view of a heating shaft, FIG. 8 shows a detail in section of the heating shaft according to FIG. 7,

FIG. 9 shows an axonometric representation of a corner region of the heating shaft,

FIGS. 10 to 12 different stages of the assembly of parts to form a heating shaft,

FIG. 13 schematically shows the deformation of the parts by means of two stamps,

FIG. 14 shows a side view of a heating shaft,

FIG. 15 shows a section along the line II-II in FIG. 14,

FIG. 16 schematically shows a section through part of a heating shaft before expansion,

FIG. 17 shows a section according to FIG. 16 after expansion,

Figure 18 shows a reinforcement part in an axonometric representation and the

Figures 19 to 23 different cross sections of reinforcement parts. As can be seen from FIG. 1, which shows a section of a heating shaft 1, it has two jackets, an inner jacket 2 and an outer jacket 3. These two jackets 2 and 3 are connected to one another in their edge regions by overlapping bent edge sections 4. The edge sections 4 of the two shells 2 and 3 are provided with tooth-like projections 5, 6 and 51, 61, respectively (FIGS. 2 and 3). Of these, every second projection 6, 51 is bent by approximately 90 ° and passes through an opening 7 in the projections 5, 61 running parallel to the plane of the jacket 2, 3. As indicated by the arrows 8, the projections 5, 61 protruding sections bent, resulting in a firm connection of the two shells 2 and 3.

A bead 9 is arranged in the area of the angled protrusions 51 of the inner jacket 2 and serves to receive a circumferential round cord seal 10.

Figure 4 shows a variant of the connection of the two jackets 2 and 3, in which the two jackets 2, 3 have smooth edges which are connected to one another by a fold seam 11.

FIG. 5 shows the connection of a connecting pipe 12 to the outer jacket 3. This is provided with tubular extensions 13, the free ends of which are provided with inwardly directed flanges 14. The connecting pipes 12 have a diameter which is below the inner diameter of the flanges 14 and penetrate them. The connecting pipes 12 are provided with an upset collar 15, which is provided for contact with the outside of the flanges 14.

The end of the connecting tube 12 inserted into the tubular extension 13 of the outer jacket 3 is deformed into an outwardly directed flange 16, a circumferential seal 17 in the form of an O-ring being inserted between the flanges 16 and 14.

The embodiment according to FIG. 6 differs from that according to FIG. 5 in that a ring 18 with flat end faces is inserted between the flange 16 of the connecting pipe 12 and the seal 17.

FIG. 7 shows a heating shaft 1 in plan view, which encloses a rectangular interior 21. The heating shaft 1 has a double jacket 19, consisting of an inner jacket 2 and an outer jacket 3, in the narrow sides of which 20 tubes 21 of a lamella heat exchanger are inserted. These tubes 21 are connected to one another via transition arches formed by bulges 22.

As can be seen from FIGS. 8 and 9, the bulges 22 are enclosed by areas 23 in which the outer jacket 3 lies tightly against the inner jacket 2. The inner jacket 2 of the heating shaft 1 is provided with molded pipe stubs 24, in which the pipes 21 are inserted tightly.

A region 25 extends in the entire circumference of the heating shaft 1, in which the inner jacket 2 is distanced from the outer jacket 3, resulting in a space 26 through which a medium to be heated can flow. 3 beads 27 are incorporated into the outer jacket, in the area of which the inner jacket 2 and the outer jacket 3 are connected to one another by spot welding or soldering.

FIGS. 10 to 12 show the joining and connecting of the inner shell 2 to the outer shell 3.

As can be seen from FIG. 10, the inner jacket 2 and the outer jacket 3 are plugged together, these being formed by pressed parts, and provided with the bulges 22, the pipe socket 24 and the pipes 21. The plugging together results in substantially congruently curved regions 28 and 281 in the edge region, to which obliquely extending almost straight sections 29 and 291 are connected. This is followed by a further curved region 30 and 301, the two curvatures running in an S-like manner and these not corresponding to the final shape of the heating shaft 1 and having a gap.

As can be seen from FIG. 11, the angle of the inclined section 29, 291 is reduced in a second step, as a result of which the curved areas 28, 281 come together in their edges adjoining the narrow sides of the heating shaft 1 and in the curved area 28, 281 for tight contact and the gap almost disappears. In this area, absolute tightness can be achieved by welding.

According to the transition from the state according to FIG. 11 to that of FIG. 12, the concave part 37, 371 of the double curvature is converted into a convex, which represents the final state. A single rounding 36 is obtained from the curvatures 28, 30 and 37 as well as 281, 301 and 371.

As can be seen from FIG. 13, this deformation is carried out by means of two punches 31 and 37. The punch 31 supports the curved region 281 of the inner casing 2 and is moved towards the longitudinal side 34 in accordance with the arrow 33. At the same time, the punch 32 is moved in accordance with the arrow 35.

In an additional operation according to FIG. 12, a rounding 36 is formed, in which the inner jacket 2 lies tightly against the outer jacket 3.

As can be seen from FIGS. 14 and 15, the heating shaft 1 has two jackets 2 and 3 spaced apart from one another, the outer jacket 3 being penetrated by two connecting pieces 38 and 39, via which a medium to be heated flows in and out can. As can be seen from FIG. 14, the two shells 2 and 3 are connected to one another at different points 40, for example by means of welding points, in addition to their edge regions in which they are tightly connected to one another.

The heating shaft 1 is produced in such a way that the two jackets 2 and 3, apart from their angled edge regions 41, 42, are essentially flat. The edge regions 41, 42 are tightly connected to one another, for example welded. The space remaining between the two walls 2 and 3 is pressurized with a pressure above the specified test pressure after the connection of the edge regions and the point-by-point connections have been made via the connecting pieces 38, 39. This leads to a widening of the space between the two shells 2 and 3 due to a plastic deformation of the two shells 2, 3.

The connection points 40, which are distributed over the entire circumferential surface of the heating shaft 1, largely prevent the two jackets 2, 3 from bulging, so that the heating shaft 1 is essentially prismatic in shape. The walls 2, 3, however, have various deformations which are caused by the connection points 40, as shown in FIG. 15.

As can be seen from Figure 2, 1 reinforcing parts 43 are arranged in the corner regions of the heating shaft. FIG. 18 shows an embodiment of such a reinforcement part 43 which, as can also be seen from FIG. 19, has an essentially comb-like cross section. The web 45 connecting the legs 44 is curved, its curvature corresponding to the desired curvature of the outer jacket 3.

FIGS. 20 to 22 show cross sections of reinforcing parts 43, FIG. 20 showing a meandering cross section, FIG. 21 a zigzag cross section and FIG. 22 a serpentine cross section. In all of these cross sections there is a certain minimum distance between the shells 2, 3.

In the embodiment according to FIG. 23, a shaped tube with a rectangular cross section is provided, which is bent accordingly in order to follow the desired curvature of the outer jacket 3.

Claims

1. A method for producing a double-walled heating shaft of a burner-heated water heater, in which the inner and outer shells are tightly connected to one another in edge areas and which is provided with connecting pipes for the supply and discharge of a heating medium flowing through the heating shaft, characterized in that the inside - And the outer jacket (2, 3) are provided by cutting with edge sections, which are placed against each other in their edge regions with the interposition of a seal, preferably a round cord seal (10), and are then connected to one another by comprehensive bending.

2. Ver ears according to claim 1, characterized in that the two jackets (2, 3) of the heating shaft (1) are connected to one another by a seam (11).

3. The method according to claim 1, characterized in that the edge regions of the two Jackets (2, 3) of the heating shaft (1) are provided with openings (7) into which tooth-like projections (6, 51) of the respective other jacket (2, 3) are inserted, the projecting sections of the projections (6, 51 ) are bent.

4. The method according to any one of claims 1 to 3, da¬ characterized in that at least one of the two heating shafts (1) forming shells (2, 3) is provided in the edge region with a bead (9) for receiving the seal.

5. The method according to any one of claims 1 to 4, da¬ characterized in that the outer casing (3) of the heating shaft (l) for receiving the connecting pipes (12) with tubular approaches (13) is provided, which at their free ends with against the axles of the shoulder (13) facing flanges (14) are provided and the connecting pipes (12) have a diameter which is below the inner diameter of the corresponding flange (14) and penetrate them, the connecting lines (12) being on the outside of the flanges (14 ) have adjacent shape and at their ends inserted into the tubular lugs (13) to form an outwardly directed flange (16) are deformed and a circumferential seal (17) is interposed between the flanges (16) of the connecting pipes (12) and the flanges (14) of the tubular extensions (13) of the outer casing (3).

6. The method according to claim 5, characterized in that between the flange (16) of the corresponding connecting tube (12) and the seal, preferably an O-ring (17), a ring (18) is inserted with a substantially flat end faces.

7. The method according to claim 5 or 6, characterized gekenn¬ characterized in that the shape of the connecting pipe (12) is formed by upsetting a collar (15).

8. A method for producing a double-walled heating shaft of a burner-heated hot water device in which the inner and outer shells are tightly connected to one another in edge areas and which is provided with connecting pipes for the supply and discharge of a heating medium flowing through the heating shaft, into which pipes of a finned heat exchanger can be inserted are, wherein the inner shell forming pressed parts bulges, which form a transition bend from one pipe socket to an adjacent pipe socket, are provided against the pipe socket enclosed by the double jacket and the outer jacket forming press parts, the transition bends being surrounded by areas in which the inner jacket and the outer jacket abut one another , whereas in the other areas the inner jacket is distanced from the outer jacket, characterized in that the inner jacket (2) and on the outer jacket (3) in the transition areas between the bulges (22) forming the transition arches and the areas in which the outer jacket (3 ) is distanced from the inner jacket (2), oblique sections (29, 291) are formed, to which curved sections (28, 281) are connected, the inner jacket (2) being connected to the outer jacket (3) in order to connect them and then between two stamps (31, 32) supporting the curved areas (28, 281) and deformation of the obliquely running sections (29, 291) are pressed against one another, the curved regions (28, 281) being pressed tightly against one another by changing the angle of the obliquely running sections (29, 291).

9. double-walled heating shaft, which is produced by the method according to claim 8, and in which tubes of a finned heat exchanger are inserted, the inner jacket having pipe sockets directed towards the space enclosed by the double jacket, into which tubes of a finned heat exchanger are inserted, and the outer jacket bulges, form the transition arches from a pipe socket to an adjacent pipe socket, the transition arches being surrounded by areas in which the inner jacket and the outer jacket lie close together, whereas in the other areas the inner jacket is spaced from the outer jacket, characterized in that after the Pressing the radius of the curved area (28) of the outer casing (3) against one another is greater than the radius of the curved area (281) of the inner casing (2) that is increased by the casing thickness and there is no gap between the outer casing (3) and the inner casing between closely adjacent sections antel (2) remains in the area of the curvature.

10. A method for producing a double-walled heating shaft of a burner-heated hot water device, in which the interior and the Outer jacket are tightly connected to one another in edge areas, which is provided with connecting pipes for the supply and discharge of a heating medium flowing through the heating shaft and which is designed to be pressure-resistant, prismatic with rounded edges up to a provided test pressure, characterized in that the interior space between the connected ones Jackets (2, 3) of the heating shaft (1) are subjected to a pressure above the intended test pressure and both jackets (2, 3) are plastically deformed.

11. The method according to any one of claims 1 to 10, da¬ characterized in that in cross-section flat, the shells (2, 3) forming sheets, which are optionally angled in the edge zones, are used.

12. The method according to any one of claims 1 to 10, characterized in that before connecting the two jackets (2, 3) of the heating shaft (1) in the corner regions of the heating shaft (l) reinforcing parts (43) are introduced, whose cross-section determines a minimum clear distance extending in the direction of the axis of the heating shaft (1).

13. The method according to any one of claims 1 to 10, characterized in that the two jackets (2,

3) of the heating shaft (1) before the test pressure is applied to the interior space delimited by them, except in the areas of the dense, continuous connection zones, at several points.

14. Double-walled heating shaft, produced by the method according to claim 12, characterized gekennzeich¬ net that the reinforcing parts (43) are comb-like in cross-section, the web (45) connecting the leg (45) optionally corresponding to the curvature of the corner region.

15. Double-walled heating shaft, produced by the method according to claim 12, characterized gekennzeich¬ net that the reinforcing parts (43) are meandering in cross section.

16. Double-walled heating shaft, produced by the method according to claim 12, characterized gekennzeich¬ net that the reinforcing parts (43) are zigzag in cross section.

17. Double-walled heating shaft, produced by the method according to claim 12, characterized gekennzeich¬ net that the reinforcing parts (43) are formed in a serpentine cross-section.

18. Double-walled heating shaft, manufactured by the method according to claim 12, characterized gekennzeich¬ net that the reinforcing parts (43) are formed by rectangular tubes in cross section.