EP0595945B1 - Double-walled heating section - Google Patents

Abstract

A double-walled heating section with a heat exchanger for a burner-heated circulatory or through-flow water heater with at least one finned tube contained in a heating section in the form of a water-filled double-walled section in which the burner is fitted, whereby the finned tube is connected in series with the double-walled section on the water side and arranged in the upper region of the double-walled section. In order to ensure that any gas bubbles occurring are reliably removed in such a heat exchanger, the finned tube (4) is surrounded by extensions (2) of the double-walled section (1) only on two opposite sides lying in the extension of the fins (5) of the fined tube (4), said extensions (2) communicating with a further water pipe, and an outward or return pipe being connected to one of the extensions (2).

Description

The invention relates to a heating shaft according to the preamble of the independent claim. Such a heating shaft is e.g. known from DE-A-2 221 801.

In these heating shafts, however, there is the disadvantage that gas bubbles, in particular air bubbles, emerge from the water circulating in the double jacket and collect in the top area facing away from the burner in dead spaces with little flow. These accumulations of gas bubbles can only be discharged from the double jacket with the known solutions only with difficulty.

The aim of the invention is to avoid this disadvantage and to propose a heat exchanger of the type mentioned in the introduction, in which a safe flow is also ensured in the upper regions of the double jacket.

According to the invention this is achieved by the characterizing features of the independent claim.

In this way it is ensured that gas bubbles emerging from the heating water can only collect in the attachments of the double jacket. However, since they are connected to one another and to the finned tube, these are appropriately flowed through, so that escaping gas bubbles are entrained safely.

According to claim 2 or 3, there is a simple separation of the water streams flowing through the double jacket and its attachments, but an ascending gas bubbles in the attachments is easily possible.

It can be provided that the supply or return is connected to one of the two attachments and the other attachment is connected to a branch of the finned tube. This ensures that a partial flow of the total water throughput flows through the attachments.

In order to be able to withstand the operating pressures without causing the heating shaft to deform, the latter is preferably provided with beads according to claim 4. By means of these measures, the outer and inner walls are not only connected to one another along the upper and lower edges, but also at a number of locations distributed over the outer and inner walls. This results in a very rigid construction of the heating shaft, so that its walls can be made relatively thin. The beads lead to stiffening of the walls and a large number of connection points, which are expediently formed by welding points, prevent bulging of the walls due to the internal pressure.

According to claim 5 results in a guidance of the flowing water through the beads.

The measures according to claim 6 have the advantage that no pipe bends are required for the connection of the heating shaft, which is cooled by the medium to be heated, with the tubes of the finned heat exchanger and the connection of the tubes of the finned heat exchanger with one another, so that a noticeable space saving results. In addition, this also results in a reduction in the outlay for producing the heating shaft and the finned heat exchanger.

Claim 7 ensures that the flow is supplied with the slightly higher temperature water from the upper area of the double jacket and the flow connection can still be arranged in the lower area.

The channel can be formed by a bulge, preferably on the outside of the double jacket. It can also be provided that the channel is also connected in its lowermost region to the interior of the double jacket via an overflow opening. This makes it possible to largely completely empty the double jacket, even though the channel leads away from the uppermost region of the double jacket. In normal operation, the overflow opening does not lead to any significant mixing of the water drawn off via the channel with the water located in the lower region of the double jacket.

In order to ensure the removal of gas bubbles and gas pockets, a vent tube can also be provided. As a result of the flow through the upper region of the double jacket, a slight negative pressure is generated, as a result of which any gas bubbles and pockets that are formed are suctioned off and transported away via the ventilation tube and the outlet connection.

The measures according to claim 9 ensure that the suction opening of the vent tube is located in the area in which gas or air bubbles and pockets are most frequently formed. In this way, the air heater can be operated largely free of air bubbles. In addition, there is no need for the ventilation tube to pass through a wall of the double jacket.

However, it is also conceivable for the vent tube to run outside the double jacket or / and for the vent valve to be arranged in accordance with claim 11.

The invention is explained in more detail below with the aid of figurative representations.

• Figuren 1 und 2 zwei verschiedene Ausführungsformen eines erfindungsgemäßen Heizschachtes,
• Figuren 3 bis 5 einen weiteren Heizschacht in perspektivischer Ansicht und Schnitte entlang den Linien IV-IV beziehungsweise V-V gemäß Figur 3,
• Figuren 6 und 7 ein weiteres Ausführungsbeispiel eines Heizschachtes in Seiten und Stirnansicht,
• Figur 8 eine teilweise geschnittene Vorderansicht eines weiteren erfindungsgemäßen Heizschachtes,
• Figur 9 eine Seitenansicht des Heizschachtes nach Figur 8,
• Figuren 10 und 11 teilweise geschnittene Detailansichten des Heizschachtes nach Figur 8,
• Figur 12 eine weitere Ausführungsform eines erfindungsgemäßen Heizschachtes,
• Figur 13 einen Schnitt entlang der Linie XIII-XIII gemäß Figur 12,
• Figur 14 einen Querschnitt durch einen erfindungsgemäßen Heizschacht,
• Figur 15 eine Seitenansicht des Doppelmantels nach der Figur 14,
• Figur 16 eine teilweise geschnittene Vorderansicht eines weiteren erfindungsgemäßen Heizschachtes,
• Figur 17 eine teilweise geschnittene Rückansicht des Heizschachtes nach der Figur 34,
• Figur 18 eine Seitenansicht des Heizschachtes nach Figur 34 und
• Figur 19 eine teilweise geschnittene Detailansicht des Heizschachtes nach der Figur 34.

Show:

• FIGS. 1 and 2 show two different embodiments of a heating shaft according to the invention,
• FIGS. 3 to 5 a further heating shaft in a perspective view and sections along the lines IV-IV or VV according to FIG. 3,
• FIGS. 6 and 7 show a further exemplary embodiment of a heating shaft in a side and end view,
• FIG. 8 shows a partially sectioned front view of a further heating shaft according to the invention,
• FIG. 9 shows a side view of the heating shaft according to FIG. 8,
• FIGS. 10 and 11 show partially sectioned detailed views of the heating shaft according to FIG. 8,
• FIG. 12 shows a further embodiment of a heating shaft according to the invention,
• FIG. 13 shows a section along the line XIII-XIII according to FIG. 12,
• FIG. 14 shows a cross section through a heating shaft according to the invention,
• FIG. 15 shows a side view of the double jacket according to FIG. 14,
• FIG. 16 shows a partially sectioned front view of a further heating shaft according to the invention,
• FIG. 17 shows a partially sectioned rear view of the heating shaft according to FIG. 34,
• FIG. 18 shows a side view of the heating shaft according to FIGS. 34 and
• FIG. 19 shows a partially sectioned detailed view of the heating shaft according to FIG. 34.

In all figures, the same reference symbols mean the same details.

In the embodiment according to FIG. 1, a double jacket 1 is provided with attachments 2 on two opposite sides, in the embodiment according to FIG. 1 the front attachment is connected to the double jacket 1 via a front constriction 3.

A finned tube 4 is arranged between the two attachments 2, the fins 5 of which are held between the attachments 2. The water pipe 6 held in the fins 5 is laid in a serpentine line. The one attachment 2 is connected via a pipe 7 to the water pipe 6 of the finned pipe 4, the two attachments 2 being connected in series with one another via a pipe 8. The lead 9 is connected to that attachment 2, which is not connected to the water tube 6 of the finned tube 4 via the tube 7, namely at the end of the attachment 2 which is flowed through last in the flow direction.

As indicated by the arrows shown in FIG. 1, the heating water first flows through the lamella tube 4, a part of the water flow entering the one attachment 2 of the double jacket 1 and flowing through it. This partial flow enters the second attachment 2 via the pipe 8.

The main flow enters the lower part of the double jacket 1 in the corner region thereof via a bend 10 adjoining the finned tube 4. There the water flow divides and flows over a wide and long side of the double jacket 1 to the connection of the lead 9th

The water to be heated flows through the connection 11 of the water pipe 6, which is connected to the return line, into the finned tube 4 and occurs at the flow connection 9, after flowing through the finned tube 4 and the double jacket 1 together with attachments 2. The constriction 3 is only at the front, so that the water can get from the lower part of the double jacket 1 to the connection of the flow 9 arranged in its attachment 2.

In the embodiment according to FIG. 2, the constriction 3 is missing between the double jacket 1 and the attachments 2, which are likewise connected to one another via a tube 8. Furthermore, the connection of the water pipe 6 of the finned pipe 5 to one of the attachments 2 is also missing.

In this embodiment, the water after flowing through the finned tube 6 via the elbow 10 into the double jacket 1 in one corner area. From there, the water flow divides, so that the two longitudinal sides of the double jacket 1 are flowed through in parallel in the same direction.

This also leads to a flow through the attachments 2 of the double jacket 1, as shown by the arrows. Any air bubbles that are present are entrained and carried away.

In this embodiment, the attachments 2 are connected to the water pipe 6 of the finned pipe 4 via the double jacket 1. In the region of each longitudinal side of the double jacket 1, the water flow is divided into a partial stream flowing through the actual double jacket 1 and a partial stream flowing through the top section 2 thereof Partial flow, wherein the partial flow flowing through the attachment 2 not connected to the feed 9 is fed via the pipe 8 to the connection of the feed 9.

In the embodiment of a double jacket 1 according to FIG. 3, which has attachments 2 on its two longitudinal sides, for a heat exchanger, the attachment 2 is separated from the double jacket 1 via a constriction 3 which extends over most of the length of the attachment 2. In this case, a channel 16 is formed on one end of the attachment 2, which extends downward to a connection 14 to which, for example, the flow of a heating circuit or other heat consumer can be connected.

As can be seen from FIG. 4, the constriction is very deep, so that only a small clear cross section remains, which is sufficient, however, to allow any gas bubbles escaping from the heating water to pass through, but not to enable a noteworthy water exchange. It is therefore possible to introduce water into the attachment 2 via a connection 12 in the latter and to force a flow which ensures that any gas bubbles that are accumulated are entrained.

The channel 16 is expediently formed by an outwardly projecting bulge 15 of the outer wall 18 of the double jacket 1 together with the attachment 2, a cover 13 extending essentially along the outer wall 18 of the lower area of the double jacket 1 being arranged in the area of the channel 16, which is connected at the top to the inner wall 19 of this area of the double jacket 1.

The two attachments 2 of the double jacket 1 are connected to one another via a tube 8.

The water is introduced into the lower region of the double jacket 1 via the pipe socket 20 and into the attachments 2 via the connection socket 12.

As can be seen from FIG. 5, an overflow opening 17 is arranged in the lowermost region of the cover 13, which enables a practically complete emptying of the double jacket 1, for example for dismantling from a heater, although the connection 14 via the channel 16 is also included the uppermost area of the double jacket or its attachment 2 is connected.

The embodiment according to FIGS. 6 and 7 differs from that according to FIGS. 3 to 5 only in that the channel 161 connecting an attachment 2 to the connection 14 has a kink and extends to the narrow side of the lower part of the double jacket 1. In this embodiment too, an overflow opening is arranged in the area of the connection 14 in the cover separating the channel 161 from the lower area of the double jacket 1.

A heating shaft 1a as a combustion chamber according to FIGS. 8 to 11 is designed as a double jacket 1, as can be seen from FIG. The inner wall 19 is not shown in FIGS. 8, 9 and 10. A space 21 through which a medium to be heated, for example water, can flow is provided between the outer wall 18 and the inner wall 19.

The outer wall 18 is connected in some areas to the inner wall 19, beads 22 being arranged distributed over the surface of the outer and inner walls 18, 19, the bottoms of which lie against one another and allow additional connection points there, for example welding points, in order to increase the rigidity of the double jacket 1 to increase and avoid bulging under pressure.

The double jacket 1 is provided with an inlet connection 11 and an outlet connection 14 for the medium to be heated.

A ventilation tube 24, which is open in this area, ends in the area of a ventilation nozzle 23 attached at the top. This vent tube 24 leads to the outlet connection 14 and opens essentially in the direction of the axis and in the flow direction of the medium of the outlet connection 14, as a result of which a negative pressure is created in the region of the mouth opening of the vent tube 24. This is due to the flow of the medium through the outlet connection 14. This negative pressure acts via the ventilation tube 24 in the upper region of the heating shaft 1 a, where the ventilation tube 24 has its inlet end, whereby any air bubbles and pockets that accumulate in this region are sucked off via the ventilation tube 24 and transported away through the medium flowing through the outlet connection 14.

A vent screw, not shown, is provided in the uppermost region of the same for venting the double jacket 1 during the first filling, which is kept open during filling and is closed tightly after the double jacket 1 has been completely filled. This bleed screw is located in the bleed nozzle 23.

As can be seen from FIGS. 9 and 10, two vent tubes 24 lead into the outlet connection 14, which lead to the uppermost regions of the two side walls 25, 26, between which the tubes of the fin heat exchanger, not shown, with fins, the deflection chambers 27 of which are held are visible.

In the embodiment according to FIG. 12, the heating shaft 1a is made of stainless steel sheet by a double jacket 1, which encloses an interior 28 provided with an atmospheric gas burner and which is formed by tightly connected outer walls 18 and inner walls 19. The two walls 18 and 19 are tightly connected in the upper and lower region of the heating shaft 1a by means of weld seams 29.

An intermediate space 21 remains between the outer and inner walls 18, 19 that can be produced and then soldered from copper sheet, and the medium to be heated flows through it during operation. The space 21 extends, as can be seen from FIGS. 17 to 19, over all four walls of the heating shaft 1 a.

This can be connected to cold water supply and hot water discharge lines via inlet or outlet connections (not shown).

In the upper area of the side walls 321 and 331, which are formed by the webs 32, 33 of two U-shaped parts 34, 35, the legs 36 and 37 of which are butt-welded together with tight weld seams, tubes 31 of a finned heat exchanger 30 are held. Openings 38 are arranged in the inner walls 19 of the mutually opposite side walls 321 and 331, which are surrounded by collars 39 projecting into the interior of the heating shaft 1a, into which the tubes 31 of the finned heat exchanger 30 are inserted, and are tightly connected to them.

Beads 22 are incorporated into the inner and outer walls 19 and 18, the beads 22 arranged in the inner wall 19 and outer wall 18 being arranged essentially congruently. The bottoms 40 of the beads 22 of the inner wall 19 lie against the bottoms 40 of the beads 22 of the outer wall 18, the bottoms 40 of the beads 22 being connected to one another by welding points.

The outer wall 18 of the side walls 25 and 26 is provided with bulges 41, which are surrounded by areas 42 in which the inner wall 19 bears closely against the outer wall 18, the bulges 41 extending over two openings 38 of the corresponding inner wall 19 and as deflection bends serve for the water flowing through the tubes 31. A bulge 43 further connects that region of the side wall 25 in which there is a space 21 between the outer wall 18 and the inner wall 19, with a tube 31 of the heat exchanger 30 so that the water can flow from the space 21 into the heat exchanger 30.

The inlet and outlet connections, not shown, are arranged on the outside of the side wall 26.

FIG. 14 shows a heating shaft 1 a in which a gas burner 68 which is fed from a gas line 67 provided with a gas valve 66 is arranged, the heating shaft 1 a being formed by a double jacket 1 which is filled with water. This has a constriction 3 in its upper region.

The gas burner 68 is assigned to the lower region 84 of the heating shaft 1a, whereas the heat exchanger 30 is assigned to the upper region 83 facing away from the gas burner 68. The arrangement of gas burner 68 and heat exchanger 30 is common to all embodiments.

When using a lintel burner, in contrast to the exemplary embodiment just described, it lies above and the heat exchanger 30 below in the heating shaft 1a.

In the upper region 83 of the double jacket 1, the gas emerging from the water which is in the clear space of the double jacket 1 collects.

Because of the constriction 3, there is only a very small water flow in the upper region 83 of the double jacket 1, if any.

In the uppermost area 71 of the heating shaft 1a, a vent valve 72 designed as an automatic float valve is arranged, which is located with its connecting line 73 above the double jacket 1, the gas accumulated in the area 71 being able to be discharged via the vent valve 72.

As can be seen from FIG. 15, the constriction 3 is formed from squeezing points 74 arranged in a row, in which the two walls of the double jacket 1 practically abut one another, but free passages 75 are provided between these squeezing points 74.

The gas water heater according to FIGS. 14 and 15 can be used as a domestic water heater or as a heat source for a circulating heater.

Figures 16 to 19 correspond in terms of operation to Figures 8 to 11, wherein the ventilation tubes 24, instead of being arranged in the space 21, are located on the outer wall 18 and only the pipe ends 85 through the outer wall 18 or the connection 14 in the Protruding space.

This arrangement has the advantage that there is no obstruction of the pipes when joining the inner and outer shafts. It is also possible to replace the pipes at a later date.

Claims (11)

1. Heating chamber with a heat exchanger for a burner-heated closed-circuit or instantaneous water heater with at least one multiple-blade water conduit (4) held in the heating chamber designed as a water-filled double-shell casing (1) and accommodating the burner, with the multiple-blade conduit (4) communicating hydraulically with the double-shell casing and being arranged in an area of the heating chamber which is heated by the burner, characterized in that the multiple-blade conduit (4) is enclosed on two mutually opposite sides, which are located laterally of the multiple blades (5) of the multiple-blade conduit (4), by two top pieces (2) of the casing (1), connected with each other by a conduit (8), with at least one of the two top pieces (2) being connected with the multiple-blade conduit (4) for the purpose of a partial volume of flow of the water passing through it, and with an upstream conduit (9) being connected to the top piece (2) located downstream of the conduit (8).
2. Heating chamber as claimed in Claim 1, characterized in that at least one of the two top pieces (2) is separated from the double-shell casing (1) by a constricted portion (3).
3. Heating chamber as claimed in Claim 2, characterized in that the constricted portion (3) is formed by crimp points (74) where the two walls of the double-shell casing (1) are essentially contacting each other and between which free passages (75) are provided.
4. Heating chamber as claimed in Claim 1, characterized in that the internal wall (19) and the external wall (18) of the double-shell casing (1) are provided with beaded portions (22), the bottoms (40) of which are in contact with each other, with the internal and external walls (19, 18) being connected with each other in these bottom areas.
5. Heating chamber as claimed in Claim 4, characterized in that the beaded portions (22) are essentially parallel to the upper and/or lower rim of the double-shell casing (1).
6. Heating chamber as claimed in Claim 5, characterized in that on two opposite sides of the double-shell casing (1) the internal walls (19) are provided with apertures (38), each aperture having a collar (39) extending towards the inside of the heating chamber (1a), these collars (39) being connected with the conduits (31) of the multiple-blade heat exchanger (30), further that the external walls (18) are provided with outwardly extending first bulges (41) which are surrounded by the areas where the internal walls (19) are in close contact with the external walls (18) and each of which ex-tends over the area of two apertures (38) connected with the conduits (31) of the multiple-blade heat exchanger (30), and that on the external wall (18) on one side of the heating chamber (1a) a second bulge (43) is provided which extends into that area of the external wall (18) in which a through hollow space (21) exists between the internal and the external walls (19, 18).
7. Heating chamber as claimed in any of the preceding claims, characterized in that the upstream port (14) is arranged in that portion of the double-shell casing (1) which faces the burner and is connected by a passage (16) with the portion of the double-shell casing facing away from the burner.
8. Heating chamber as claimed in any of the preceding claims, characterized in that at least the portion of the double-shell casing (1) which faces away from the burner is provided with a small open venting tube (24) which essentially extends in the direction of the axis of the upstream port (14) and opens into the latter.
9. Heating chamber as claimed in Claim 8, characterized in that the venting tube (24) ends above the connection between the top piece (2) and the multiple-blade conduit (4) inside the double-shell casing (1), extends inside the hollow space of the latter and opens into the upstream port (14).
10. Heating chamber as claimed in Claim 9, characterized in that the venting tube (24) ends above the connection between the top piece (2) and the multiple-blade conduit (4) inside the double-shell casing (1), extends outside the hollow space of the latter and opens into the upstream port (14).
11. Heating chamber as claimed in any of the preceding claims, characterized in that a venting valve (72) is provided which is connected with the upper portion of one of the two top pieces (2).

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