Heating boiler driven by a liquid or a gaseous fuel

SWEDEN (12) PUBLICATION PAPER

09) SE (51) International class³ mie.) 7711077-3 F 24 H 1/28

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(44) Application submitted and publication document published (41) Application widely available (22) Patent application submitted (24) Maturity date

Patent Office (62) National application number (86) International filing date (86) Filing date for European patent application (30)

82-06-14 (11) Publication 423 930 number

78-04-10

77-10-04 _A , ,

Application received as:

H Swedish patent application □ Completed international patent application with number

O converted European patent application with number

76-10-09 DE 2645717 (71) Applicant: H (72) Inventor (74) Representative: von (54) Name:

fuel

VIESSMANN, BATTENBERG / EDER, DE Search.

Rennenkampff

Heat boiler for combustion of liquid or gaseous

7711077-3

The invention relates to a heating boiler for combustion of liquid or gaseous fuels, especially for minor effects, consisting of a water-bearing housing of steel plate in which a cylindrical chamber for receiving the combustion chamber and the hot gas channels is provided with coupled reversing chambers which are surrounded by a plurality of surrounds. , spaced apart from each other, drawing ducts communicating with the flue gas chamber with flue gas outlet.

Boilers of this type are known, for example, according to CH-PS 485 182 or DT-PS 1 778 880. These known boilers may meet the requirements for best heat exchange, but the practical realization and a profitable manufacture, however, cause considerable problems why such boilers probably have not entered the market.

Also of interest here is the embodiment according to these patents in which in a cylindrical sheath U- or near U-shaped plate profiles are inserted on the inner wall of the boiler and welded firmly. On the other hand, such boilers cannot easily withstand large temperature differences, especially not the lower temperatures of, for example, 60 ° C due to the associated corrosion risks.

Even with such a design of the hot gas ducts in such boilers, they ultimately do not meet the requirements of a profitable and practical manufacture or an equally life expectancy, nor, finally, possible optimum heat transfer conditions and favorable corrosion conditions, it must also be borne in mind that boilers designed for lesser effects than about 10-25000 kcal / h - such boilers are in demand today with regard to energy savings through improved thermal insulation of the heated spaces - require a disproportionately increased production cost that cannot be reduced by reducing material costs. because of the small dimensions.

It is therefore the object of the invention to improve boilers of this kind so that the aforementioned claims can be realized at least optimally, ie a boiler in particular for smaller effects of the order of 10-25000 kcal / h, which can easily be produced profitably and which is sufficient for functional heat transfer and which, because it controls the condensate falling in certain operating phases, can also be used in the lower temperature ranges.

This task is solved by a heating boiler according to the invention according to which the cylindrical chamber is formed as a thin-walled, in condensation-critical areas, unworked cast iron body which goes through square or annular steel and back walls, which with their edges are waterproofly connected to the cast body, arranged in the region of the combustion chamber radially inwardly directed walls Kr which support a combustion chamber sleeve and laterally restrict the draft duct.

Thus, this solution combines both the favorable properties of unprocessed castings with respect to condensate engagement and partly the good machining ability of steel sheet, whereby, in addition to the design of the cylindrical chamber of cast iron, also the tensile ducts in this area are eliminated and thus all the welding work in this area is eliminated. Advantageously, in order to provide good heat transfer conditions for the insertable combustion chamber sleeve to the walls, these can be provided with narrow swells which can be machined on their plant surfaces without further cutting to obtain a good installation of the combustion chamber because the walls do not reach the temperature.

Since the walls are not themselves water-filled but well the wall of the cylindrical chamber from which the molded walls are formed, these can advantageously be formed with open slots to compensate for the different thermal stresses.

For waterproof insertion of the cylindrical chamber in it

7711077-3 The outer steel housing is the chamber so designed that at its ends it is waterproof for the dog with steel rings that are embedded in each collar on the chamber. Preferably, these plating rings can be pressed onto the externally heated collars.

Even with regard to various heat conduction, the rings can be provided with an annular recess which causes a reduction in wall thickness. The rings are inserted together with the chamber - insofar as they do not immediately shelf front and back walls - in corresponding large openings in the front and back wall of the boiler house, and are welded together with this. In view of the convenient insertion of the chamber provided with rings from one side, the rings, if the housing is already finished, can be made with different outer diameters. If the rings themselves form the front and rear walls of the outer casing, they need only be enclosed in a cylindrical steel sleeve and welded.

An embodiment of the invention is described below with reference to the accompanying drawing in which Fig. 1 shows a longitudinal section through the boiler;

As can be seen from Fig. 1, the entire "inner boiler" consists of a molded cylindrical chamber 1, which is simultaneously cast with slots 14 provided with slots 14, so as to form draft ducts 6 which are bounded against the interior of the boiler by inner surfaces 5 and inwardly by an insertable combustion chamber sleeve 7 of, for example, stainless steel. . The walls 9 are provided with narrow ends 13 at their free ends 12, the surfaces 13 'of which for good installation are machined to fit with the combustion chamber sleeve. The resulting damage to the condensate-resistant casting skin is not critical in this area because the walls there are always warmer than 60 ° 0. However, walls 9 'in a reversing chamber 10 and in the flue gas chamber 11 are not machined and are not higher than about 3-10 mm but are thinner than the walls 9 and are certainly warmer than the outer cooled walls of these chamber regions. By the arrangement of the walls 9 ', the possible condensation in the lower region is reduced to a minimum.

The casting design of the chamber 1 with the walls 9 makes it possible without any other to make the height of the walls different so that the combustion chamber sleeve 7 can be placed eccentrically upwards, whereby due to the changed drag resistance there is obtained a more favorable gas distribution in the channels, as indicated in Fig. 2 with dashes. Nor does it entail any difficulties in placing walls, for example, in the lower part of the turning chamber 10 and the flue gas chamber 11 ^rThe 9 * denser, thereby keeping the hot gas more efficiently away from the cold walls ·

The critical connection between the castings and the steel sheet itself is very easily resolved as shown in Fig. 1, in that the plate rings 16 which preferably form the front and rear walls 3 and 4 of the boiler housing and in this case are welded to a cylindrical steel outer housing 21, are at the molding shrunk into protruding collars 17 on the outside of the walls of chamber 1, or also so that the collars 17 (Fig. 3) are machined on the inner diameter 18 for watertight connection to the walls 16; for which purpose the wall edges 19 are more or less bent outwards so that a kind of shrinkage flange is formed. In view of the different thermal expansion ratios between castings and steel, the walls 16 are provided with annular recesses 20 whereby a certain weakening of the wall is obtained.

Since the places on the boiler casting body 2 where the break-in and the capacitor-resistant casting skin destructive machining must be undertaken, such machining is placed in non-critical places.

Another advantageous embodiment illustrated in FIG. 2 is so designed that walls 9 of the turning chamber 10 and the flue gas chamber 11 in both lower quadrants are inclined downwardly so that the condensate deposit lies on the free edges of the walls 9, ie where the walls are the most dense. thereby securely obtaining an extension of the condensate and preventing condensation in the attachment of the walls. The walls 9 can hereby be held slightly higher than shown for example in Fig. 1

The cylindrical shape of the entire boiler shown in Fig. 1 is not necessary, ie the boiler can also be made rectangular externally while the chamber 1 and / or the casting body 2 are kept cylindrical.