CA2290269A1

CA2290269A1 - Heat exchanger

Info

Publication number: CA2290269A1
Application number: CA 2290269
Authority: CA
Inventors: Kurt Taupadel
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-11-24
Filing date: 1999-11-23
Publication date: 2000-05-24
Also published as: DE19854089A1; JP2000161874A; EP1004840A1

Abstract

A heat exchanger is formed of sections arranged in a row, particularly for hot water central heating systems. The sections of the heat exchanger are portions of extruded polygonal tubes of aluminum or aluminum alloys with two sides which are arranged opposite each other and extend parallel to each other. The sections are arranged in a row with these sides placed on each other and are connected at the sides. The sides have in the upper and lower areas thereof recesses which form openings of the sides. The upper and lower end faces of the sections are tightly closed by a bottom and a cover.

Description

BACKGROUND OF THE INVENTION
1. Field of the Inventioa The present invention relates to heat exchangers formed of sections arranged in a row, particularly for hot water central heating systems.

2. Description of the Related Art Sections for heating elements serving as heat exchangers were originally cast, for example, of grey cast iron. A more economical manufacture resulted from punching out always two side panels of sheet steel, wherein, after embossing the indentations determining the later hollow space, the two side panels were placed on top of each other and welded along their circumference.
These types of sections have the disadvantage that special tools must be prepared for every desired shape, for example, with respect to the height or width of the section, so that only a few models were manufactured in practice and an individual adaptation to predetermined desired dimensions was not possible. Moreover, it was considered a disadvantage that only the surface areas of these sections was available for transferring heat to the space air, so that, for introducing predetermined heating outputs into rooms, large heating elements with an undesirably high number of sections were required.
However, also known in the art are blade-type heating elements which, for transferring the heat to the room air, have additionally welded-on convection plates, wherein, however, multiple-part tools of different dimensions were required for the manufacture of these blades.

SUb~IARY OF THE INVENTION
Therefore, it is the primary object of the present invention to provide heat exchangers which are capable in an inexpensive manner to adapt to individual dimension requirements, particularly with respect to the height of the sections, wherein simultaneously also the required total size can be reduced by improving the heat transfer from the sections to the surrounding or room air.
In accordance with the present inventions, the sections of the heat exchanger are portions of extruded polygonal tubes of aluminum or aluminum alloys with two sides which are arranged opposite each other and extend parallel to each other. The sections are arranged in a row with these sides placed on each other and are connected at the sides. The sides have in the upper and lower areas thereof recesses which form openings of the sides. The upper and lower end faces of the sections are tightly closed by a bottom and a cover.
Consequently, the present invention utilizes a plurality of polygonal tubular profiles which are individually cut from extruded tubes and may be essentially endless, wherein these profiles permit a significant increase of the contact surface with the ambient air and make it easily possible to additionally increase the chimney effect.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF TgE DRAWING
In the drawing:
The single Figure of the drawing is a horizontal sectional view showing an embodiment of the heat exchanger according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawing is a horizontal sectional view showing two sections 1 of a heating element. These sections 1 are each formed by portions of a closed polygonal tube which is extruded of aluminum or an aluminum alloy, for example, in pieces having a length of 6 m. Portions are severed from these extruded tubes, wherein the length of the portions corresponds to the desired height of the heating element. As shown in the drawing, these portions are placed with their parallel sides 2 one against the other and are connected to each other. Specifically, the ends of the sides 2 are connected to each other through longitudinal profiles 3 which, together with the sides 2, form a rectangular closed profile. This profile can be further reinforced by a transverse wall 4. Webs 5 extend from the longitudinal profiles 3 which support a catenary-shaped outer contour 6. This produces a single or double inner space 7 for the heat-transferring liquid to which are connected the webs 5 supporting the contours 6 and form chimney-like convection ducts 8 which advantageously influence the discharge of heat.
The connection to the next adjacent section 1 can be constructed in different ways. It has been found useful to connect the sides 2 which face each other and are placed on each other by an adhesive layer 10 which simultaneously also has a sealing effect. Since it is anyhow necessary to provide a connection for passage of the heat-transferring liquid, it has been found useful for utilizing this for securing the connection.
For example, the connection can be effected by a tongue arrangement in which circular holes are produced in the upper area of the adjacent sides 2 and simultaneously the edges of these holes are pulled in the pressing direction through the holes. Utilizing an appropriate counter tool, the pulled-through edge can additionally be bent over so that a type of hollow rivetting is achieved in addition to a sealing effect by the adhesive layer 10. Since the return flow of the heat-carrying liquid has to take place in the lower area, the same connection is provided in the lower area of the sides 2.
However, it has been found that it is not absolutely necessary to punch circular holes; it is easily also possible to provide, for example, one of the sides with a differently shaped hole, for example, a square breakthrough and to equip the contacting side with appropriate breakthroughs in which the two oppositely located sides are additionally provided with downwardly directed bent sheet steel tabs. In that case, after the sections 1 or their sides 2 have been placed against each other and the sheet steel tabs have been moved through, the connection can be bevelled in such a way that a secure mechanical connection is achieved in addition to the connection and the sealing effect provided by the adhesive layer 10.
However, it is additionally necessary when selecting a double interior space 7 for the sections 1, to transfer the heat-conducting liquid from one of the interior spaces 7 of a section into the adjacent interior space. It is also in this case possible to punch holes into the sides, however, a simpler possibility is to provide cutouts 11 in the areas of the upper edge and of the lower edge of the separating transverse wall 4.
After the heating element has been essentially finished and the sections 1 have been connected, the heating element is closed towards the bottom by a bottom 12 and towards the top by a cover 13. The bottom 12 as well as the cover 13 extend at least between the two outer sides 2 of the heating element to be constructed and the row of all of the longitudinal profiles 3. In this connection, an additional mechanical connection can be achieved by slightly stepping back, for example, the end faces of all sides 2 relative to the longitudinal profiles 3 so that the bottom 12 and the corresponding cover 13 are located with their long end faces between the longitudinal profiles 3 and the upper or lower sides thereof rest on the end faces of the sides 2. The bottom 12 and the cover 13 can be provided so as to extend over all sections 1 of the heating element. However, they may also be interrupted, for example, also several times, always at an end of a section and they may also only extend over one section of the heating element.
The connection of the bottom or bottoms 12 and of the cover or covers 13 to the sections 1 can be effected in different ways;
glued connections as well as welded connections or the like can be used. However, it is always necessary that a mechanically reliable and sealed connection is provided.
If the bottom 12 and the cover 13 have a rectangular shape corresponding to the rectangle formed by the side height and the sum of the longitudinal profiles, convection ducts are provided and the webs 5 as well as the contours 6 enter the computations additionally as heat-discharging surfaces and, thus, increase the surface area which discharges heat, as it is the object of the present invention. However, it is also possible that the cover surface extends over the convection ducts 8, wherein it would be in that case advantageous to construct the cover like a screen or a protective grid.

A lower capacity for the heating liquid, a generally lower operational weight and a faster throughput of the heating medium can be achieved by including displacement bodies. Closed metal or plastic containers can be used as displacement bodies as well as plastic foam rods having preferably closed pores.
The surface area of the sections 1 can be emphasized by providing the individual elements with different colors. It is recommended to anodize this surface in color. However, it is also possible to provide chrome-plated, varnished or plastic-coated surfaces or surface elements. In each case, the resistance to corrosion is improved.
In order to adapt to layouts of the room receiving the heating element, a corresponding configuration of the heating element is possible in which the individual sections are not connected directly to each other, but sections are arranged spaced apart from each other or individual groups can be formed which are connected through appropriate intake and discharge lines. For example, fillet welds make it possible independently and/or subsequently to mount stirrups which serve for receiving various mechanical devices, for example, towel dryers or also, for example, loudspeakers, simple additional placement surfaces or the like.

The connections of the heating element can be effected through conventional fittings 9 sealingly screwed into a hole of an outer side 2. However, it has been found useful to arrange the connections in the bottom areas of an outer section 1 having two internal spaces 7, wherein one internal space 7 is connected to the forward flow and the second internal space is connected to the return flow, and wherein the internal space 7 is divided and advantageously an upper and a lower internal space are provided.
When the section is divided in this manner, a valve for controlling the heating system can be mounted and the control elements of this valve can extend outwardly without problems, while the valve itself bridges the upper and lower internal spaces.
For connecting the sections, it is also possible to use the so-called clinch method and sealing members in the form of rubber rings can be used for sealing, wherein the rubber rings are advantageously placed in embossed areas. It is also possible to provide the passage opening and the rubber seal in the clinch element which now has a bore.
Particularly during transition periods, heating is advantageously carried out by providing at least one or more of the sections with electric heating elements. It is also possible to construct a radiator with one section or with a small group of sections.
While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

1. A heating element formed of sections arranged in a row especially for hot water central heating systems, each section comprising a portion of an extruded polygonal tube of aluminum or an aluminum alloy with two parallel sides which are located opposite each other, wherein the sections are placed against each other with their sides and are connected at the sides, wherein the sides have in an upper area and in a lower area thereof recesses forming openings, and wherein upper and lower end faces of the sections are sealingly tightly closed by a bottom and a cover.

2. The heat exchanger according to claim 1, wherein the sides placed against each other are at least over areas thereof connected by an adhesive layer producing a seal and a connection.

3. The heat exchanger according to claim 2, wherein the adhesive layer is a permanently elastic adhesive layer.

4. The heat exchanger according to claim 1, wherein cutouts forming openings extend from at least one of an upper edge and a lower edge of the sides.

5. The heat exchanger according to claim 1, wherein a recess arranged in an upper area of the side is located below an outer edge of the side and a recess arranged in a lower area of the side is located above an outer edge of the side.

6. The heat exchanger according to claim 1, wherein the recesses of sides placed against each other are arranged so as to coincide and have bent edges for effecting an additional mechanical connection.

7. The heat exchanger according to claim 1, wherein each polygonal tube has longitudinal profiles connecting the sides.

8. The heat exchanger according to claim 7, wherein each longitudinal profile has middle transverse walls for reinforcing the longitudinal profiles, wherein the transverse walls have upper and lower cutouts.

9. The heat exchanger according to claim 7, wherein the longitudinal profiles have additional outwardly extending profile portions.

10. The heat exchanger according to claim 9, wherein the longitudinal profiles additionally have ribs with free ends connected to a contour member.

11. The heat exchanger according to claim 1, comprising clinched connections between the sides of the sections.

12. The heat exchanger according to claim 1, wherein a breakthrough is provided at the connection between the sides, and wherein a sealing ring is mounted at the breakthrough.

13. The heat exchanger according to claim 1, wherein sections are mounted spaced apart from each other and lines conducting heating medium connect the sections.

14. The heat exchanger according to claim 1, wherein at least one section has a control valve.

15. The heat exchanger according to claim 14, wherein a closed internal space is formed in the internal space of a section, wherein the closed internal space is bridged by the control valve, and wherein control elements of the control valve extend outwardly.

16 16. The heat exchanger according to claim 1, comprising displacement bodies mounted in the internal spaces of the sections for reducing the capacity of the internal spaces.

17. The heat exchanger according to claim 16, wherein the displacement bodies are box-shaped of sheet metal or synthetic plates or are of plastic foam bodies with closed pores.

18. The heat exchanger according to claim 1, further comprising fillet welds between the sections for receiving legs of support stirrups.

19. The heat exchanger according to claim 1, wherein at least one of the sections comprises electric heating elements.

20. A radiator comprised of a plurality of sections arranged in a row, wherein each section comprises a portion of an extruded polygonal tube of aluminum or an aluminum alloy with two parallel sides which are located opposite each other, wherein the sections are placed against each other with their sides and are connected at the sides, wherein the sides have in an upper area and in a lower area thereof recesses forming openings, and wherein upper and lower end faces of the sections are sealingly tightly closed by a bottom and a cover.