EP1767880A1 - Heating device - Google Patents

Abstract

The device has a heat exchanger that is made of an aluminum-cast material and forms a combustion chamber (2) and a heating gas draft (3). A displacement body is provided for controlling the heating gas, and consists of an upper part (7a) near the combustion chamber and a lower part (7b) attached to the upper part. The lower part of the displacement body consists of a fixed base body with a flexible casing fixed in a portion.

Description

The invention relates to a heater according to the preamble of claim 1.

Heat exchangers for generic heaters, which are designed for operation with calorific value, are made of cast aluminum materials. For example, heat exchangers having a cylindrical shape are known. These form as one-piece cast body in an upper portion of a combustion chamber and in a lower portion of at least one hot gas, are provided on the exposed with hot gases inside with ribs and have at least one channel for the heating medium, which conducts heat in contact with the delimiting walls.

At least one displacement body is arranged in the center of the finned region of the heat exchanger in the case of generic heaters in order to steer the heating gases emerging from the combustion chamber uniformly outwards into the heat transfer surfaces and to avoid direct flow into the region of the exhaust collector. This displacement body is usually designed so that it can be removed during maintenance work on the combustion chamber. It is optionally made in one piece or consists of a combustion chamber near upper part with a lower part associated with this.

In connection with the use of aluminum casting materials in heaters, there may be gradual corrosion phenomena, especially in the finned area exposed to hot gases, after longer periods of operation. These erosion effects are known and regarded as unproblematic in terms of the device life. The reason for this is that in condensing boilers, part of the water vapor produced by the combustion of gas is condensed. In addition, small amounts of nitrous and sulfuric acid formers. These also condense, are absorbed in the condensation, and thus form a very low concentrated acid. By changing the temperature with evaporation of water, it can locally come to concentration of the acid, so that then occurs especially at these points, the aluminum corrosion.

Usually, therefore, a cleaning of the finned heat exchanger area is required for heaters after prolonged operation as part of a maintenance. The cleaning can be done, for example, with a brush or with a high-pressure water jet. For this, the heat exchanger area to be cleaned for the cleaning tool must be accessible. In a heat exchanger with a cylindrical shape or a round cross-section is located in the middle of a continuous channel, which must be closed by a guide or displacement body during operation of the heater. The channel serves as access for a brush or the nozzle of a high-pressure cleaner. Because of the occurring corrosion and the volume growth of the corrosion products, it may happen that known displacement body, especially in the lower part of the heat exchanger stuck and even baked, because its outer shell is fixed over a large area to the surrounding ribs. This problem arises essentially by the cylindrical shape of the outer shell and the very precise fit, namely, according to the requirements allow only a small gap to the surrounding ribs. During maintenance, the displacement body can then be removed only with difficulty and extra effort.

The invention is therefore based on the object to ensure in a heater that, in particular in a manufactured from an aluminum casting heat exchanger arranged in the center of the ribbed region displacement body for guiding the hot gases even after prolonged periods of operation and strong attack of corrosion products from the aluminum Cast material is still easy to remove.

This is achieved with the features of claim 1 according to the invention. Advantageous developments can be found in the dependent claims.

The heater is characterized in that at least the lower part of the displacement body consists of a rigid base body with an associated, fixed thereto and flexible at least in a partial area jacket. When installed, the jacket of the displacement body or at least a portion of the shell abuts the tips of the ribs in the center of the heat exchanger or is located at a very small distance therefrom. At the top of the combustion chamber facing the displacement body is provided with a handle.

The displacement body consists in a first embodiment of a metallic or ceramic, cup-shaped base body with a wound from a coil spring jacket in the hot gas applied to the zone. In this case, the individual turns of the coil spring are close together in the installed state of the displacement body. The coil spring made of corrosion-resistant material or corrosion-resistant surface is fixed only in an upper portion of the shell of the body and down adjoining subregion of the body has a smaller outer diameter, thereby ensuring a distance from the surrounding coil spring. Optionally, the body may be closed at the bottom with a lid.

In a second embodiment, the displacement body consists of a metallic or ceramic base body with a shell made of a temperature-resistant fiber knit or fiber fabric. The textile cover is attached to the base body so that it inverts when pulling downwards. Before the replacement, the shell can then be simply pushed back. The main body preferably consists of an upper part and a to be connected to this, the fiber knit or fiber fabric on the jacket receiving, smaller diameter lower part. The textile shell also has a capillary action by sucking the acidic condensate slightly out of the critical area of corrosion. This reduces the tendency to caking.

In a third embodiment, the displacement body consists of a metallic or ceramic base body, which is at least in the lower portion of the shell with a string of temperature-resistant fibers, in particular glass or Keramikfasem, spirally wound. The cord is preferably fixed to the underside of the base body, so that it unwinds when pulling out of the displacement body from below and therefore can be torn off continuously with little force from the surrounding heat exchanger, because the force always acts only on a small area. The basic body also consists here of an upper part and a to be connected to this, the cord on the jacket receiving, smaller diameter lower part. Before reinstalling the cord is wound up again on the metallic body and fixed with tape, for example.

In a fourth embodiment, a displacement body is provided, which consists of a concrete body as a base body with a shell made of a temperature-resistant fiber knit or fiber fabric, in particular glass or Keramikfasergestrick exists. The acid formation described occurs pronounced in the gap between the fin tips and the body of the corrosive. Now, if the acid is immediately neutralized there in the area of origin, it can no longer cause corrosion. The displacement body acts in this way when the concrete is made in an advantageous embodiment of Portland cement with lime chippings as a filler. The acid reacts with the cement to gypsum and

Kalksalpeter, so that the concrete body is slowly consumed. As the concrete is poured into the envelope, this jacket contributes to mechanical strength even when thermal cracks occur in the concrete body. In addition, the fiber fabric absorbs the thin acid, distributes it over the surface of the concrete body and thus ensures a homogenization of the consumption. The resulting reaction products are not water-soluble sludges and remain partially embedded within the tissue jacket. Despite its depletion, the displacement body retains its shape and function for a very long time, and the neutralization effect reduces the corrosion so that the displacement body does not cork over time and can easily be removed.

In a fifth embodiment, the displacement body consists of several metallic or ceramic discs, which are stacked and fixed alternately with spacer elements on a bolt passing through them in the center. This design offers plenty of space between the panes for the corrosion products that form on the heat exchanger. There are only relatively small surfaces of the heat exchanger fins directly opposite, so that even with the strong attack of corrosion products of the displacement body can hardly get stuck. When removing the individual discs can move and deform elastically with the application of tensile force, so that the force is relatively low.

In a sixth embodiment, the displacement body has a cylindrical core region with a cover on the underside and a shell of a spiral-shaped leaf spring fixed thereto. In this case, the core area is fastened with an end face on an upper part, so that when dismantling by turning the upper part of the mantle reduced in diameter and thus optionally detached from the surrounding ribs.

In a seventh embodiment, the displacement body consists of a metallic or ceramic base body, which is provided at least in the lower portion of the shell with at least one ring, in particular of an elastomeric material. To accommodate the ring groove-like depressions are provided on the jacket, according to its dimensions. In this variant, the main body forms a relatively large gap for ribbing the heat exchanger, which is then largely or completely closed with one or more elastomer rings. Preferably, O-rings made of Viton or rings with sealing lips can be used. The gap creates space for the corrosion products and spatially separates the corroding parts. The extraction of the displacement body is facilitated because the rings can deform, slip or roll.

In an eighth embodiment, the displacement body as a whole consists of a temperature-resistant elastomeric material. However, at least the shell of the displacement body in the lower portion of a temperature-resistant elastomeric material is executed, which is fixed to a metallic or ceramic body. When pulled out stretches the elastomer body, thereby reducing its diameter and thus dissolves well from the surrounding heat exchanger.

In general, the displacement body can be provided on the outer jacket with the use of elastomeric materials in the upper part close to the combustion area with a shielding plate or a shielding sleeve. Advantageously, this is attached so that an insulating air gap is formed between the jacket and the shielding plate or the shielding sleeve.

Furthermore, a tool for releasing the displacement body from the heat exchanger and for removing the same via the combustion chamber is provided according to the invention. It is characterized by an attachable to the handle of the displacement body, tubular housing having a receptacle for the handle of the displacement body in the lower region. This is designed as a slot with slightly tapered flanks. The tool is placed over the handle and can be mounted free of play and tightly by turning by about 90 °. In the case a Schlaggewicht is led, which is to accelerate by a simple tool, such as a screwdriver, is inserted into an opening at the top.

With the construction according to the invention is ensured in a heater, in particular in a heat exchanger made of an aluminum casting material, a displacement body for guiding the hot gases is still easy to remove, even after a prolonged period of operation and in the event of a strong build-up of corrosion products. As a result, the maintenance of the heater is facilitated because a seizing and even caking of the displacement body is reliably avoided because even with heavy attack of corrosion products of the outer shell is only occasionally or on relatively small surfaces in contact with the surrounding ribs. Particularly effective in releasing the displacement body is in this context, at least in a partial area flexible jacket, because with the deformation bending forces are selectively generated. On the other hand, nevertheless, the requirements, namely to allow only a small gap to the surrounding ribs in order to direct the heating gases uniformly outward into the heat transfer surfaces and to avoid a direct flow into the region of the exhaust manifold, satisfied by all the displacement body variants shown.

Fig. 1:

einen Wärmetauscher mit Brenner und Verdrängungskörper in einem vertikalen Längsschnitt,

Fig. 2:

einen Verdrängungskörper mit einem aus einer Spiralfeder gewickelten Mantel in einem vertikalen Längsschnitt,

Fig. 3:

einen Verdrängungskörper mit einer Hülle aus Fasergestrick in einem vertikalen Längsschnitt,

Fig. 4:

einen Verdrängungskörper mit einer gewickelten Schnur aus Fasermaterial in einer perspektivischen Ansicht,

Fig. 5:

einen Verdrängungskörper als Grundkörper zum Umwickeln mit einer Schnur aus Fasermaterial in einem vertikalen Längsschnitt,

Fig. 6:

einen Verdrängungskörper mit einem in eine Hülle aus Fasermaterial eingegossenen Betonköper in einem vertikalen Längsschnitt,

Fig. 7:

einen aus mehreren Scheiben und Distanzelementen gebildeten Verdrängungskörper in einem vertikalen Längsschnitt,

Fig. 8:

einen Verdrängungskörper mit einer Blattfeder als Mantel in einer perspektivischen Ansicht in Form einer Explosionszeichnung,

Fig. 9:

einen Verdrängungskörper mit Elastomerringen in der Vorderansicht mit Teilschnitt,

Fig. 10:

einen Verdrängungskörper, mindestens in einem Teilbereich aus einem Elastomer bestehend, in einem vertikalen Längsschnitt und

Fig. 11:

einen Wärmetauscher mit angesetztem Werkzeug zur Demontage eines Verdrängungskörpers in einem vertikalen Längsschnitt.

The drawing illustrates an embodiment of the invention. It shows as part of a heater:

Fig. 1:

a heat exchanger with burner and displacer in a vertical longitudinal section,

Fig. 2:

a displacement body with a wound from a coil spring coat in a vertical longitudinal section,

3:

a displacement body with a sheath of fiber knit in a vertical longitudinal section,

4:

a displacement body with a wound cord made of fiber material in a perspective view,

Fig. 5:

a displacement body as a base body for wrapping with a string of fiber material in a vertical longitudinal section,

Fig. 6:

a displacement body with a cast in a sheath of fiber material concrete body in a vertical longitudinal section,

Fig. 7:

a displacement body formed from a plurality of disks and spacer elements in a vertical longitudinal section,

Fig. 8:

a displacement body with a leaf spring as a jacket in a perspective view in the form of an exploded view,

Fig. 9:

a displacement body with elastomeric rings in the front view with partial section,

Fig. 10:

a displacement body, at least in a partial region made of an elastomer, in a vertical longitudinal section and

Fig. 11:

a heat exchanger with attached tool for disassembly of a displacement body in a vertical longitudinal section.

The heater consists essentially of a heat exchanger, which forms a combustion chamber 2 in the upper area around a burner 1 and at least one annular heating gas 3 in the lower area. On the treated with hot gases inside the heat exchanger is provided with ribs 4 and on the outside there is at least one channel 5 for the heating medium, which conducts heat with the limiting walls 6 in contact. In the center of the finned area, a displacement body for guiding the hot gases is arranged. This consists in the embodiment of a combustion chamber near upper part 7a and a lower part associated with this 7b. At the lower end of the heat exchanger is the exhaust manifold.

At least the lower part 7b of the displacement body consists of a rigid base body 8 with an associated, fixed thereto and at least in a partial region flexible jacket. At the upper side facing the combustion chamber 2, the displacement body is provided with a handle 9.

2, the displacement body has a wound from a coil spring 10 jacket and the metallic or ceramic, cup-shaped base body 8 is closed at the bottom with a lid 11. The coil spring 10 is fixed only in the upper part of the base body 8 and downwardly reduces its outer diameter, so that the coil spring 10 hangs there freely.

According to Fig. 3, the displacement body of a metallic or ceramic base body 8 with a shell 12 made of a temperature-resistant fiber knit or Fiber tissue built up. The main body 8 consists of an upper part 8a and a to be connected to this, the fiber knit or fiber fabric on the jacket receiving, smaller diameter lower part 8b.

According to FIGS. 4 and 5, the displacement body consists of a metallic or ceramic basic body 8, likewise with an upper part 8a and a lower-diameter lower part 8b spirally wound with a cord 13 of temperature-resistant fibers and to be connected thereto. The cord 13 is fixed in the bottom region of the lower part 8b with a clamping device 14.

6 shows a displacement body with a concrete body 16 encased in an envelope 15 of temperature-resistant fiber knit or fiber fabric, in particular glass or ceramic fiber knit, as base body 8. The handle 9 is likewise cast into the concrete body 16.

According to FIG. 7, the displacement body consists of a plurality of metallic or ceramic disks 17, which are stacked and fixed in the center with spacing elements 18 on a bolt 19 that passes through the arrangement in the center. For this purpose, the handle 9 has a thread 20 into which the bolt 19 engages from below.

The displacement body according to FIG. 8 consists of a cylindrical core region 21 with a cover 22 on the underside and a shell of a spiral-shaped leaf spring 23 fixed thereto. In this case, the core region is fastened to an upper part 25 via a plurality of tabs 24.

9, the displacement body consists of a metallic or ceramic base body 8, which is provided approximately on the lower half of the shell with a plurality of rings 26 made of an elastomeric material. Also, the jacket of the displacement body, as shown in Fig. 10, in the lower portion of a temperature-resistant elastomeric material. For this purpose, a cap-like, cylindrical element 27 is provided in the embodiment, which surrounds the base body 8 on the entire underside and laterally engages in an associated groove 28 on the circumference. In this case, an insulating air gap 29 can be formed between the cap-like element 27 and the lateral surface of the base body 8.

In addition, as shown in FIGS. 9 and 10, the displacement body may be provided in the upper, burner-near subregion of the main body 8 with a shielding plate 30 on the outer Be provided coat. Here, too, an insulating air gap 31 is formed between the shielding plate 30 and the underlying lateral surface of the main body 8. For disassembly of the displacement body or its lower part 7b, the tool shown in Fig. 11 is used. It consists of a tubular housing 32 and is attached with a designed as a slot hole 33 in the lower part of the handle 9 of the displacement body and fixed by a rotation by about 90 °. In the housing 32 an axially displaceable impact weight 34 is guided, which is to accelerate with a simple tool that can be inserted into an opening 35 at the top.

Claims (13)

Heater, in particular with a manufactured from an aluminum casting heat exchanger, which forms a combustion chamber (2) and at least one Heizgaszug (3), is provided on the exposed with hot gases inside with ribs (4) and in the center of the finned region at least one displacement body for directing the hot gases, wherein the displacement body either in one piece or from a combustion chamber near upper part (7a) with a lower part associated therewith (7b) and wherein the displacement body can be seen on the combustion chamber,
characterized in that at least the lower part (7b) of the displacement body consists of a rigid base body (8) with an associated, fixed thereto and at least in a partial area flexible jacket. Heater according to claim 1,
characterized in that the jacket of the displacement body or at least a portion of the shell in the installed state at the tips of the ribs (4) in the center of the heat exchanger is applied or is located at a very small distance thereto. Heater according to claim 1,
characterized in that the displacement body is provided on the combustion chamber (2) facing top with a handle (9). Heater according to one of claims 1 to 3,
characterized in that the displacement body consists of a metallic or ceramic, pot-like basic body (8) with a wound from a coil spring (10) jacket, wherein in the installed state of the displacement body, the individual turns of the coil spring (10) are close together, wherein the coil spring (10) is fixed only in an upper portion of the shell of the base body (8) and wherein the downwardly adjoining portion of the base body (8) has a smaller outer diameter and thereby ensures a distance from the surrounding coil spring (10). Heater according to one of claims 1 to 3,
characterized in that the displacement body of a metallic or ceramic base body (8) with a sheath (12) consists of a temperature-resistant fiber fabric or woven fabric, wherein the textile sheath (12) is fixed to the base body (8) that they pull out everting downwards, and wherein the base body (8) consists of an upper part (8a) and a to be connected to this, the fiber knit or fiber fabric on the jacket receiving, smaller-diameter lower part (8b). Heater according to one of claims 1 to 3,
characterized in that the displacement body consists of a metallic or ceramic base body (8), which is at least in the lower portion of the shell with a string (13) of temperature-resistant fibers, in particular glass or Keramikfasem, spirally wound, wherein the cord (13) is preferably fixed to the underside of the main body (8), so that it unwinds when pulling out of the displacement body from below, and wherein the main body (8) from an upper part (8a) and to be connected to this, the cord (13) on the jacket receiving, smaller diameter lower part (8b) consists. Heater according to one of claims 1 to 3,
characterized in that the displacement body of a concrete body (16) as the base body (8) with a sheath (15) made of a temperature-resistant fiber knit or fiber fabric, in particular glass or Keramikfasergestrick, and that the concrete in the sheath (15) is poured. Heater according to one of claims 1 to 3,
characterized in that the displacement body consists of a plurality of metallic or ceramic discs (17), which are stacked and fixed with spacer elements (18) on a bolt passing through the assembly (19) altemierend in the center. Heater according to one of claims 1 to 3,
characterized in that the displacement body has a cylindrical core region (21) with a cover (22) on the underside and a shell of a spiral-shaped leaf spring (23) fixed thereto, the core region (21) having an end face on an upper part (25). is fastened, so that shrinks by turning the upper part (25) of the jacket in diameter. Heater according to one of claims 1 to 3,
characterized in that the displacement body consists of a metallic or ceramic base body (8) which is provided at least in the lower portion of the shell with at least one ring (26), in particular of an elastomeric material, wherein for receiving the ring (26), according to its dimensions, groove-like depressions are provided on the jacket. Heater according to one of claims 1 to 3,
characterized in that the displacement body as a whole consists of a temperature-resistant elastomeric material or the jacket of the displacement body at least in the lower portion of a temperature-resistant elastomeric material which is fixed to a metallic or ceramic base body (8). Heater according to one of claims 1 to 11,
characterized in that the displacement body has a shielding plate (30) or a shielding sleeve on the outer jacket in the upper part close to the burner, and in that an insulating air gap (31) is formed between the jacket and the shielding plate (30) or the shielding sleeve. Heater according to one of claims 1 to 12,
characterized by a tool attachable to the handle (9) of the displacement body for releasing the displacement body from the heat exchanger and removing it via the combustion chamber (2), comprising a tubular housing (32) with a receptacle (33) for the handle (9) of the displacement body in the lower part, which is designed as a slot with slightly conical flanks and with which the tool is to be mounted by a rotation of about 90 ° backlash-free and tight, and a guided in the housing (32), with a simple tool to be accelerated impact weight ( 34).

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