EP0519172A1 - Cast-iron heating boiler - Google Patents

Abstract

The heating boiler consists of individual elements arranged in a row, which in each case are formed in alternation from a circumferential outer shell or cylinder (6) with an inner flange (7) and a circumferential inner shell or cylinder (8) with an outer flange (9). The corelessly cast elements are sealed in relation to one another and braced, the circumferential front edges of the shells or cylinders (6, 8) fitting into cast-on guide and sealing grooves (11) on the adjacent flange (7, 9). Openings (10) in the flanges (7, 9) connect the part water spaces (1) created. <IMAGE>

Description

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

A boiler of this type is shown and described in the unpublished DE 40 32 241 A1. Cast iron boilers have so far only been built in a link structure. The individual boiler sections are formed and cast in a casting mold with inserted cores. The partial water spaces formed by the boiler sections are connected to each other at hubs. Instead, the cited document proposes to build a boiler with a single, large water space, as was previously known for steel boilers, and yet to use the recognized advantages of cast iron as a material. For this purpose, the water space limitation consists of open cast, cast iron individual elements in the form of an inner cylinder with an outer flange and an outer cylinder with an inner flange, the parts being sealed and braced against one another.

The construction described has the advantage that it can be made from cast iron. The design advantages of the casting process and the corrosion resistance of the cast iron material are used. On the other hand, a complex and environmentally harmful core manufacturing process is dispensed with.

The object of the invention was to create a boiler made up of individual elements to be strung together in order to additionally utilize the advantages of the link construction.

The boiler according to the invention has the features mentioned in the characterizing part of patent claim 1.

The boiler is made up of several individual elements. An inner shell with an encircling outer flange alternates with an outer shell with an inner flange. Flow openings in the flanges connect the adjacent water spaces. The all-round end edges of the shells are inserted into cast-on guide and sealing grooves on the flanges of the neighboring elements. This not only results in a perfect fixation, but also a secure seal. The boundary walls of the grooves also shield the sealing insert against destructive influences, which is particularly important on the heating gas side.

The stringing together of core-cast individual elements can already be gathered from EP 0 414 925 A1. The creation of partial water spaces, which are connected by flow openings in the circumferential flanges, is also disclosed there. However, there is a seal on the circumferential end edges, which is difficult to control. Sealing an end edge in an assigned groove of the neighboring element, however, is much cheaper.

The preferably T-shaped individual elements can be strung together in any number. One could also work with L-shaped elements on the same principle. Individual links would then have to be created first, which would then have to be joined together.

In a known manner, ribs can be cast onto the inwardly facing surfaces, ie towards the heating gas side. In the case of a cylindrical construction of the inner shell, cylinder rings, possibly with cast-on ribs, can also be drawn in. A hot gas side coating to increase the corrosion resistance is also easily possible. In this way, a boiler of this type can also be used as a condensing boiler if required.

In addition to a cylindrical structure of the individual elements, an eccentric assignment of the combustion chamber and hot gas flue is also possible, the inner shell encompassing both areas and the outer shell delimiting the outer water space. The combustion chamber can be designed as a flame tube that ends at the end of the heating gas flue. It is advisable to cast ribs on the cast iron inner shell in the area of the hot gas flue. A part of these ribs can be designed as guide ribs and create a division of the heating gas train into several oppositely flowing trains. A rear and front heating gas deflection can lie within the boiler body through appropriate rib design or can also be left out in the front and rear lining.

A particular advantage of a boiler of this type is that it can also be operated without condensation in low-temperature operation. For this purpose, the outer shell has a greater, preferably twice the distance from the cast iron inner shell in the area of the hot gas flue than in the area of the combustion chamber. This allows the connection of the heating flow and return to the upper, enlarged area of the water space and a targeted control of the cold and hot water flow within the water space. Vertical separating ribs cast onto the outer shell create a separation between the cool return water and the hotter supply water, with the return water flowing downwards in the outer areas. As a result of thermal buoyancy, the water heated up in the combustion chamber area then flows up again. It rinses the inner shell and shields it from direct exposure to cold return water. This prevents the formation of condensation in the vulnerable areas, especially in the lower area of the boiler.

If the heating gas flue is arranged above the combustion chamber, it is advisable to arrange separating ribs in the water space on both sides of the heating gas flue. The heating return then arrives in the two outer areas of the water space via a return distributor. The heating flow branches in the upper, middle area of the water space. There can also be two branches that open via a common flow connection.

For the frontal limitation, L-shaped elements are recommended in cross-section, which have system parts for a burner door or an exhaust gas collector on their outward-facing surfaces.

Fig. 1:

Einen Längsschnitt durch einen Heizkessel in zylindrischer Ausführung,

Fig. 2:

Ein vergrößertes Detail aus Fig. 1,

Fig. 3:

Eine Alternative zu Fig. 2,

Fig. 4:

Einen vertikalen Längsschnitt durch einen Heizkessel mit exzentrischer Zuordnung von Brennraum und Heizgaszug und

Fig. 5:

Den Schnitt A-A aus Fig. 4.

The accompanying drawing shows an embodiment of the invention. It shows:

Fig. 1:

A longitudinal section through a cylindrical boiler,

Fig. 2:

An enlarged detail from Fig. 1,

Fig. 3:

An alternative to Fig. 2,

Fig. 4:

A vertical longitudinal section through a boiler with eccentric allocation of combustion chamber and heating gas flue and

Fig. 5:

Section AA from FIG. 4.

The boiler is composed of core-free cast individual elements, which form a water space 1 from several adjacent partial water spaces and a combustion chamber 2. In the combustion chamber 2 there is a reversing chamber 3 for deflecting the heating gases. These then flow through a ring-cylindrical heating gas flue 4 or a heating gas flue 4 'arranged eccentrically to the combustion chamber 2 to the rear exhaust pipe 5. In a different boiler structure, a flame tube could also be inserted into the combustion chamber. The decisive factor is the assembly of the boiler from the special individual elements.

The elements alternately consist of an outer shell 6 (in the case of a cylindrical boiler structure, an outer cylinder) with a circumferential inner flange 7 and an inner shell 8 (in the case of a cylindrical boiler structure, an inner cylinder) with a circumferential outer flange 9. The inner and outer flanges 7, 9 have openings 10 which point to them can be distributed over the entire scope. These openings 10 can also encompass almost the entire cross section of the flanges 7, 9, so that only connecting webs 28 remain between the shells 6, 8 (FIG. 5). At the end of the flanges 7, 9 or the connecting webs 28 sits a circumferential guide and sealing groove 11, in which the end edge of the adjacent shell 6 and 8 is inserted. An inserted sealing ring 12 ensures the seal. The bracing takes place either with continuous anchor rods or in the indicated manner with short anchors 13 from element to element. In order to shield the sealing ring 12, the boundary wall 14 of the sealing groove 11 on the heating gas side must be made particularly high. Both on this wall 14 and on the inner shell 8, fins 15 are cast, which protrude into the heating gas flue 4 or into the combustion chamber 2.

With a T-shaped design of the elements, any number of elements are alternately strung together. End-side limiting elements 16 are L-shaped in cross section. They have a system part 17 for a burner door 18 on the burner side and an attached or cast-on exhaust gas collector 19 or rear wall 19 'on the flue gas side. In the case of an L-shaped design, two elements of the boiler element are combined. The boiler sections can then be assembled in a known manner.

In the case of an eccentric arrangement of combustion chamber 2 and heating gas duct 4 'according to FIGS. 4 and 5, the inner shell 8 within the heating gas duct 4' is penetrated by a number of transverse ribs 20. Horizontal flow shafts are created and, as a result of central guide ribs 21, a double train. A special design of the transverse ribs 20 of the end elements forms a front and a rear turning chamber 22. These turning chambers 22 could also be omitted in the brickwork of the front burner door 18 or the rear wall 19 '.

In the area of the heating gas flue 4 ', the water space 1 has a large volume. Vertical separating ribs 23 divide the water space into outer zones, into which the heating return 24 opens out via a return distributor 25, and an inner zone, from which the heating feed 26 branches off. A direct loading of the combustion chamber wall with cold return water is prevented. There is no condensation.

The individual elements can be easily molded horizontally. A coreless cast is possible. The application is not limited to the boiler shown. Arbitrarily shaped boilers can be created in modular construction.

Claims (10)

Boiler made of cast iron with a water space limitation made of open molded, cast iron individual elements in the form of an inner shell (8) with a cast-on outer flange (9) and an outer shell (6) with a cast-on inner flange (7), which are sealed against one another and braced, characterized in that several Individual elements connected in series from the inner shell (8) with the outer flange (9) and outer shell (6) with the inner flange (7) are joined together in a link structure, the circumferential end edges of the shells (6, 8) being molded into a molded guide and sealing groove (11 ) on the flanges (7, 9) of the neighboring elements and openings (10) for connecting adjacent water spaces (1) are provided on the outer and inner flanges (9, 7). Heating boiler according to claim 1,
characterized in that the individual elements are T-shaped in cross-section and have sealing grooves (11) on both sides of the flanges (7, 9). Heating boiler according to claim 1,
characterized in that the individual elements are L-shaped in cross-section and have a sealing groove (11) on one side of the flanges (7, 9). Boiler according to claims 1 to 3,
characterized in that the cast-iron inner and outer shells (6, 8) are each cylindrical in shape, with the inner shells (8) facing inwards, ie toward the heating gases, and the inner boundary wall (14) of the groove (11) or cast-on cylindrical cast-iron cylinder ribs (15) and that a flame chamber (3) is inserted into the ring of the ribs (15) to form an annular cylindrical heating gas flue (4). Boiler according to claims 1 to 3,
characterized in that the cast iron inner shell (8) each has a combustion chamber (2) and an eccentrically arranged heating gas duct (4 ') and the cast iron outer shell (6) a water chamber (1) surrounding the combustion chamber (2) and the heating gas duct (4') limited. Heating boiler according to claim 5,
characterized in that the cast iron inner shell (8) in the area of the heating gas flue (4 ') is penetrated by a number of transverse ribs (20), with horizontally oriented guide ribs (21) dividing the heating gas flue (4') into a plurality of trains flowing in opposite directions cause a rear and front heating gas deflection (22). Heating boiler according to claim 5,
characterized in that the cast iron outer shell (6) has a greater distance from the cast iron inner shell (8) in the area of the heating gas flue (4 ') than in the area of the combustion chamber (2) and that both the heating flow (26 ) and the heating return (24) is connected. Heating boiler according to claim 7,
characterized in that the heating flow (26) and the heating return (24) are separated within the water space (1) by vertical separating ribs (23) cast onto the outer shell (6) via intermediate webs. Boiler according to claims 7 and 8,
characterized in that vertical separating ribs (23) are arranged in the water space (1) on both sides of the heating gas flue (4 ') and in that the heating return (24) opens into the two outer regions of the water space via a return distributor (25) while the heating flow (26) branches off in the upper, middle area of the water space. Boiler according to claims 1 to 9,
characterized in that the end-side limiting elements are L-shaped in cross-section and have contact parts (17) for a burner door (18) or an exhaust gas collector (19) on their outward-facing surface.

Images