EP0477116B2 - Boiler with reinforced intermediate elements - Google Patents

Description

The present invention relates to a boiler improved cast iron element type comprising at least one intermediate element reinforced heat exchanger with surfaces additional exchange.

More specifically, the additional areas exchange of each intermediate element reinforced exchanger pass through the combustion chamber.

The invention also relates to such an intermediate element reinforced heat exchanger for boilers in medium and high power cast iron in the area of domestic, collective heating and semi-industrial.

The boilers covered by the invention are made up of a horizontal succession of elements exchangers assembled together by juxtaposition horizontal using tie rods and nipples.

We know the invention described in the patent French FR-A-2,071,754 in the name of BUDERUS which refers to a formed heating boiler juxtaposed exchanger elements.

These exchanger elements conventionally comprise vertical flues that connect the fireplace to upper collector channels. The only peculiarity of this boiler concerns the presence substantially vertical guide ribs arranged on or conformed in surfaces heat exchange as well as horizontal baffles provided on them at different heights.

This invention does not provide any structure of exchange leading the water and crossing the room combustion.

So if the ribs and baffles existing on the exchanger elements of this invention provide well an extra yield, this one is limited and some room space from combustion remains unused.

For reasons of construction, size and performance or element performance exchangers, the length of the combustion chamber such boilers increases rapidly from a certain power. This augmentation is so fast that the combustion chamber quickly becomes noticeably longer than the flame or exceeds the standard lengths.

In these conditions, the boilers do not work not in optimal conditions and present prohibitive lengths that are hardly compatible with the current compactness research for boiler rooms.

Problems are solved for the boiler according to claim 1.

• la figure 1 est une vue en élévation de l'élément échangeur intermédiaire renforcé équipant la chaudière selon l'invention ;
• la figure 2 est une vue schématique en coupe verticale selon la ligne II - II de la figure 1 d'une telle chaudière montrant l'emplacement des éléments échangeurs intermédiaires et la circulation des gaz et fumées de combustion.

The technical characteristics and other advantages of the invention are set out in the description which follows, given by way of nonlimiting example on an embodiment with reference to the accompanying drawings in which:

• Figure 1 is an elevational view of the reinforced intermediate exchanger element fitted to the boiler according to the invention;
• Figure 2 is a schematic view in vertical section along line II - II of Figure 1 of such a boiler showing the location of the intermediate exchanger elements and the circulation of combustion gases and fumes.

• à puissance égale, elle permet de diminuer notablement le poids et le prix de revient final par un gain substantiel en matière, une réduction du temps de montage et un coût plus faible de transport ;
• la réduction de dimension des carneaux permet de diminuer la hauteur totale ;
• on peut augmenter la puissance totale de la chaudière tout en gardant son même encombrement en longueur ;
• la courbure inverse des bras d'eau permet de dégager des sections de passage suffisantes à un bon échange thermique dans le haut de la chambre de combustion et apporte une meilleure tenue aux dilatations et aux chocs thermiques.

Many advantages ensue from the present invention such as those mentioned below:

• at equal power, it makes it possible to significantly reduce the weight and the final cost price by a substantial saving in material, a reduction in assembly time and a lower transport cost;
• reducing the size of the flues reduces the total height;
• it is possible to increase the total power of the boiler while keeping its same overall dimensions;
• the reverse curvature of the water arms allows clear passage sections sufficient for good heat exchange at the top of the combustion chamber and provides better resistance to expansion and thermal shock.

We will first refer to Figure 2 which shows the principle of constitution of the improved boiler according to the invention.

Said boiler is conventionally formed a front facade element 1 on which is mounted a burner 2, for example with supply air, of a rear panel element 3 and heat exchanger elements simple intermediates such as 4 or reinforced 5, the assembly being assembled by nipples and horizontal tie rods.

The exchanger elements 4 and 5 have at upper part of flues such as 6, with spikes or with fins, arranged symmetrically in several horizontal floors.

There is a first group 7 along which combustion gases and fumes are evacuated towards the front of the boiler, along a route horizontal go A, by a compartment of return 8 from the back cover, then evacuated to the rear, along a horizontal return path B, the along a second group 9 of several floors of flues by a collector 10 of front facade.

The exchanger elements 4 and 5 have in their second half a passage from flame, respectively 11 and 12, completely free for the first or occupied by items additional exchange which will be discussed below for the latter.

The burner projects a developing flame 13 along a combustion chamber 14. formed by the succession of flame passages 11 and 12 of the different intermediate exchangers simple then reinforced delimiting a first part 15 then a second part 16.

The original feature of this boiler is located at the level of the intermediate elements reinforced 5 of which one is shown in detail on the figure 1. These reinforced intermediate elements are made up so that after assembly, the second part 16 of the combustion chamber 14 is fitted with exchange surfaces additional, formed by the presence of a group of additional water channels crossing the passage of flame and communicating with the envelope 17 of water circulation surrounding said combustion chamber.

These are channels in the form of at least two symmetrical arms 18 and 19 joined between them in the upper central part They communicate on the one hand with the water circulation jacket 17 in the upper central part of the combustion 14, and on the other hand on the side parts lower of said chamber. In order to improve the exchange, the exterior surfaces of the walls water arms 18 and 19 are provided so classic of pins or fins 20 favoring heat exchange.

These water arms 18 and 19 delimit in the flame passage section of each element reinforced intermediary 5 of the sectors adjacent to section with curvilinear contours and general shape triangular and oblong, such as a main sector lower 21 and adjacent upper 22 and 23. These sectors constitute by juxtaposition of the elements reinforced intermediate heat exchangers three separate air channels 24, 25 and 26 along from which the projection is projected, divided and evacuated aeraulic flame.

These water arms 18 and 19 contribute to a double result: significantly increase the surface area on the one hand and correspondingly decrease the length of the combustion chamber 14 to make, at equal power, the boiler notably more compact.

As can be seen in Figure 1, the concavity of these water arms is directed towards the high, contrary to the teachings of the technique previous and professional habits who sought and recommended adoption of a reverse concavity. This corresponded to two main goals: on the one hand to favor the drawing thermal of the water and on the other hand give off the most possible the combustion chamber which had imperatively remain a fully open space without any transverse element.

After assembling the boiler, the chamber combustion 14 consists of the first classic part 15 in fully open space and the second part 16 partially closed transversely by the succession of water arms 18 and 19 of the reinforced exchangers 5 juxtaposed.

The hot gases and smoke return to the front of the boiler along the flues A and are directed to the outlet of gases and fumes from combustion in the upper part of the rear panel 3 by the upper flues B arranged on several horizontal floors.

Of course, it is possible to modify the shape and number of water arms 18 and 19 in remaining in the same inventive spirit, in order to obtain better adaptation to power and imposed length of the boiler.

Claims (10)

1. Boiler of cast iron boiler type, formed by a series of heat exchange elements, made up of a front facade exchange element (1) and a rear facade exchange element (3), and of several intermediate exchange elements (4) or (5), displaying respectively a flame passage section, intermediate exchange elements forming the combustion chamber (14) or firebox of the boiler after assembly by means of juxtaposition, the exchange elements comprising a first series of flues for the passage in direction A, from the rear to the front of the boiler, and a second series of flues for the passage in direction B, from the front to the rear of the boiler, of the hot gases and combustion fumes, for them to be discharged at the rear of the boiler, and a water circulation jacket (17) surrounding the flame passage sections or the combustion gases and fumes, forming, in horizontal sequence, the combustion chamber (14) or firebox, characterised in that the firebox is formed by a sequence of two zones, these being a first zone (15), comprising exchange elements (4) with a free section (11) for flame passage, and a second zone (16) following on from the first made up, for at least part of its length, of exchange elements (5), the passage section (12) of which is traversed by several water channels, forming separate ventilation channels (24), (25) and (26), in the firebox, providing additional exchange surfaces, along which the aeraulic flow produced by the flame is divided up and guided, and by the fact that the firebox ends at the rear in the rear facade exchange element (3), with the combustion gases being sent back to the flues.
2. Boiler according to claim 1, characterised in that the internal volume of the combustion chamber (14) or firebox is taken up, over part of its rear length, by a sequence of two water arms (18) and (19).
3. Boiler according to claim 1 or 2, characterised in that the concavity of the water arms (18) and (19) is directed upwards.
4. Boiler according to any one of claims 1 to 3, characterised in that the water arms (18) and (19) communicate with the water circulation jacket (17), firstly in the upper central part of the chamber (14) and secondly through the lower side walls of the said chamber.
5. Intermediate element for the creation of the boiler according to claim 1, characterised in that the cavity of each exchange element provided for the combustion chamber (14) is traversed by additional exchange surfaces.
6. Intermediate element according to claim 5, characterised in that the additional exchange surfaces are made up of the walls of the water arms (18) and (19) traversing the combustion chamber (14), in hydraulic communication with the water jacket (17) surrounding the combustion chamber (14).
7. Intermediate element according to claim 6, characterised in that the water arms (18) and (19) number two.
8. Intermediate element according to any one of claims 5 to 7, characterised in that the concavity of the water arms (18) and (19) is directed upwards.
9. Intermediate element according to claim 8, characterised in that the two water arms (18) and (19) are symmetrical and are connected together in their upper sections, and that they communicate with the water jacket (17), firstly in the upper central section of the chamber (14), and secondly through the lower side sections of the chamber.
10. Intermediate element according to any one of claims 5 to 9, characterised in that the additional surfaces and the walls of the water arms (18) and (19) are fitted with spikes or small blades (20) favouring the heat exchange.

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