EP0763700B1 - Heater for liquid or gaseous combustibles - Google Patents

Abstract

The boiler includes a steel metal casing (1) with a cylindrical steel metal tube arrangement (4) which encloses a conversion burn chamber (2) and fuel gas supply tubes (3). A casted insert (6) forms the conversion burn chamber and limits radial arranged longitudinal rips (5) which are in contact with the cylindrical steel metal tube arrangement to conduct heat therefrom. The insert is provided with a bridge (7) at his outlet side, which is formed as a casted, uniform body with the insert. The bridge is in contact with the ends (5') of the longitudinal rips and extends along a lower half of the interior surface of the steel metal tube arrangement.

Description

The invention relates to a boiler for liquid or gaseous Fuels according to the preamble of claim 1.

Such a boiler consisting of a sheet steel / cast iron combination are well known, so that there is none in this regard special printed evidence is required. Because the through the hot gas flues along the cooled wall of the sheet steel tube train flow to the exhaust gas collection chamber and to the exhaust connection, it can be in the area on the fume cupboard side, i.e. at the end of the hot gas flues and the Exhaust gas collecting chamber to condensate precipitation come in Would corrode the sheet steel tube train over time. For this Basically, such, simply constructed and corresponding Easy to manufacture boilers so far only with permanently raised Temperature of the heat transfer medium in the housing operate.

To such, advantageously relatively simple boiler also to be able to operate in the so-called low temperature range, the invention is based, while maintaining the task simple construction with simple means to ensure that such boilers also in said low temperature range are operable.

This task is with a boiler of the type mentioned Kind according to the invention by the in the characterizing part of the claim 1 listed features solved.

By this measure, which is explained in more detail is very easy to implement, becomes the critical area of the sheet steel tube blinded, and the flowing past Heating gases no longer come directly in this area Contact with the wall cooled more by the return of the sheet steel tube train, and an otherwise observed "sweating" the boiler in this area no longer occurs. This The effect of preventing condensation is known but so far only realized on boilers (see AT-A-376 790, which are formed entirely from sheet steel, whereby for the veneering of the condensate-critical area is a separate one Made of sheet steel sleeve and inserted into the sheet steel tube must become. To give this steel sheet sleeve a hold, in a complex manner on the steel sheet profiles forming the individual trains Appropriately dimensioned cut-outs for the Sheet steel sleeve are provided.

In contrast, the one or multi-part insert made of cast iron used to immediately whose casting to shape the web, thereby making a separate sleeve becomes unnecessary and additional measures are unnecessary to hold the web in the sheet steel tube to convey. In addition, the separate assembly process for the bridge, since this automatically when installing the cast body or castings also gets into the sheet steel tube train.

Furthermore, the insert is made of cast iron from at least two parts, the web being arranged on the part arranged on the fume cupboard side is what makes it easier to cast, i.e. can be made without a core.

To achieve the desired condensate prevention effect guarantee, but on the other hand the heat transfer in the before not to impede the area, the web with its axial length only dimensioned so that the web in the area of Extension level of the bottom of the reverse combustion chamber ends. How such a design has been shown to be absolutely sufficient to to prevent the boiler from "sweating" in this area.

With regard to the heat-conductive fit in the cylindrical Steel sheet is the cast body advantageous on his Machined the circumference, and the web is on his Circumferential surface with a substantially the whole Provide wide, shallow groove, i.e. the jetty is standing in the condensate-critical area only with its relatively narrow Contact edges with the sheet steel tube in thermal contact, the insofar as is reduced to this range.

Without otherwise in the constructively simple basic concept of a Intervening boiler of the type mentioned above affects the measure according to the invention only the casting insert, the after as before in the same way in the sheet steel tube is as before, i.e. the insert is heated Sheet steel tubing inserted in this and then shrunk.

The boiler according to the invention is based on the graphic representation of an embodiment explained in more detail.

Fig. 1

schematisch einen Längsschnitt durch den Heizkessel;

Fig. 2

einen Schnitt durch den hier interessierenden Teil des Gußeinsatzes längs Linie II-II in Fig. 3;

Fig. 3

eine Ansicht des Teiles gemäß Fig. 2 in Pfeilrichtung;

Fig. 4

im Detail und im Schnitt die Anordnung des hier interessierenden Teiles des Einsatzes im Stahlblechrohrzug und

Fig. 5

den abzugsseitigen Teil des Einsatzes in Seitenansicht.

It shows

Fig. 1

schematically shows a longitudinal section through the boiler;

Fig. 2

a section through the part of the cast insert of interest here along line II-II in Fig. 3;

Fig. 3

a view of the part of Figure 2 in the direction of the arrow.

Fig. 4

in detail and in section the arrangement of the part of the insert of interest here in the sheet steel tube and

Fig. 5

the trigger-side part of the insert in side view.

As before, the boiler consists of a water-bearing one Sheet steel housing 1, with a reverse combustion chamber 2 and the heating gas cables 3 enclosing cylindrical sheet steel tube 4, in which a reversing combustion chamber 2 and the Hot gas flues 3 with radial, with the sheet steel tube in thermal contact standing longitudinal ribs 5 limiting insert 6 from Cast is arranged. The condensate-critical area is in with KK Fig. 1 denotes. For the cast insert, to which the Longitudinal ribs 5 belong, to clarify in Fig. 1, this is shown with solid lines, and the longitudinal ribs are roughly hatched. The flow of the heating gases from the reverse combustion chamber 2 through the heating gas cables 3 to the exhaust gas collection chamber AS or to the exhaust port AA is also indicated in Fig. 1 with arrows.

For such a boiler it is now essential that the use 6 at its trigger-side end region 6 ', i.e. in condensate critical Area KK with one with the ends 5 'of the longitudinal ribs 5 thermally connected, at least along the lower Inner circumferential half H of the sheet steel tube 4 extending and on its inner surface F only partially ring-shaped, axially extending web 7 and the web with the insert 6 in the form of a unitary cast body is trained. The is shown Web 7, however, all around in all exemplary embodiments. This web 7 forms with the insert or its longitudinal ribs a uniform cast body, such as in Fig. 5 in Side view is shown.

For the reasons mentioned above, the insert 6 is cast from at least two parts T, T 'are formed, and the web 7 is only arranged on the trigger-side part T '. The web 7 is also with its axial width B in the area of the extension plane E of Bottom B of the deflection chamber 2 ending dimensioned.

4, 5, the cast body is machined on its circumference, and the web 7 is also provided with a flat groove 8 which extends essentially over its entire width B. In addition, the radial ends 5 "of the longitudinal ribs 5 of the other parts T of the insert 6 are turned to ensure a tight fit of the end faces F ₁ to the sheet steel tube 4, ie all end faces F ₁ and the edges 8 'of the groove 8 delimiting Web 7 extend in a cylindrical surface.

Claims (5)

1. A boiler for liquid and gaseous fuels, comprising a water-carrying casing (1) of steel plate containing a cylindrical tubular flue (4) of steel plate enclosing the reversing combustion chamber (2) and the heating gas flues (3) arranged in which tubular flue (4) is an insert (6) of cast iron forming the reversing combustion chamber (2) and confining the heating gas flues (3) with radial longitudinal fins (5) in heat contact with the tubular flue of steel plate, characterized in that the insert (6), at the end (6') of the discharge side thereof is provided with an axially extending bridge (7) connected in heat-conductive manner to the ends (5') of the longitudinal fins (5) and extending at least along the lower internal circumferential half (H) of the tubular flue (4) of steel plate and being only in part in abutment with the inner faces (F) thereof, and that the bridge (7) with the insert (6) is in the form of a uniform cast body.
2. A boiler according to claim 1, characterized in that the bridge (7) is circumferentially arranged on the ends of the longitudinal fins (5).
3. A boiler according to claims 1 or 2, characterized in that the insert (6) is a cast body formed of at least two parts (T, T'), and that the bridge (7) is arranged on part (T') located on the discharge side.
4. A boiler according to any one of claims 1 to 3, characterized in that the bridge (7) with its axial width (B) is dimensioned to end in the area of the extension plane (E) of the bottom (B) of the reversing combustion chamber (2).
5. A boiler according to any one of claims 3 to 4, characterized in that the cast body on the periphery thereof is processed in a chip-detaching way, and that the bridge (7) is provided with a flat groove (8) substantially extending across the whole of width (B').

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