IMPROVED HEAT EXCHANGER

Description

[0001] The present invention relates to an improved boiler.

[0002] More specifically, the invention concerns a boiler comprising a cap - manifold assembly for permitting limiting the use of high temperature insulating elements and gaskets, thus permitting remarkable savings.

[0003] As it is well known, boilers used for heating or for sanitaria water production are provided with heat exchangers.

[0004] At present, many heat exchangers exist permitting obtaining high efficiency. For example, it is known in the art the spiral heat exchanger described in the European patent application EP 1281919 A, filed by the same Applicant, characterised by an inner combustion gas path through spaces among spire and tubes within which water flows.

[0005] A further example of heat exchanger that forms part of the state of the art is disclosed in the patent application No. NL 8403235.

[0006] A technical problem of prior art boilers is that known heat exchangers must be suitably thermally insulated inside. In fact, difference between Inner temperature close to the burner and outside temperature is very high. Therefore, it is unavoidable the presence of insulating elements between combustion chamber and upper cap. Said high temperature insulating elements, as well as gaskets, are comprised of very expensive refractory material that are difficult to use.

[0007] Moreover, water collector passes through the cylindrical wall. This generates further technical problems for gaskets and weldings.

[0008] A further technical problem solved by the present invention is that of insulating the internal parts of the heat exchanger, particularly in view of the fact that the temperature close to the burner is generally very high, thus reducing the use of expensive refractory material insulating elements.

[0009] Object of the present invention is therefore that of suggesting a heat exchanger with a cap - manifold assembly, permitting thermally insulating burner and combustion chamber, thus avoiding the use of refractory insulating materials, and reducing the final costs.

[0010] It is therefore specific object of the present invention to provide an improved heat exchanger comprising a water inlet duct and a water outlet duct, between which a heat exchanger is provided, comprised of a spiral duct through which water to be heated passes; said heat exchanger defining a combustion chamber within which a burner is provided, said burner being supplied by an air-gas mixture; and upper cap placed so as to be in touch with at least the last upper turn of the heat exchanger duct, and a lower cap, placed distanced from the last lower turn of the heat exchanger duct, so as to create a gap for passage of gas and discharging condensate; said heat exchanger being characterised in that it comprises a manifold element having such a surface to innerly occupy the upper surface of said combustion chamber having, a concave shape and placed above said upper cap, with the upper surface of which it realises a cavity within which an air - gas mixture is collected before being conveyed within said burner.

[0011] Always according to the invention, said upper cap can have a substantially flat upper surface.

[0012] Still according to the invention, said manifold element can be comprised of metal, preferably aluminium, or of plastic material.

[0013] Further, according to the invention, said cap can be coupled with said manifold element.

[0014] Preferably, according to the invention, coupling each other of said cap and said manifold element can be adjusted by rotation.

[0015] Still according to the invention, said heat exchanger has a metallic disk, shaped to be inserted by screwing within the space of a heat exchanger duct turn, above said heat exchanger being provided an insulating refractory element, with temperature of about 2000°C.

[0016] Furthermore, according to the invention, said disk can be comprised of steel.

[0017] Preferably, according to the invention, duct of said heat exchanger can comprise an annular slot on each end, permitting the coupling with said inlet and outlet ducts without any welding.

[0018] Always according to the invention, said heat exchanger can comprise a cylindrical element between said upper cap and said lower cap.

[0019] Still according to the invention, said heat exchanger can comprise a plurality of tie rods, each provided with means for fixing at their ends with said upper cap and with said lower cap.

[0020] Always according to the invention, said upper cap with gas manifold and said lower cap with discharge collector can be respectively realised integrally each other, or separated.

[0021] The present invention will be now described, for illustrative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein:

figure 1 shows a perspective view of a heat exchanger according to the present invention;

figure 2 shows a section of boiler according to figure 1;

figure 3 shows a section of a lower cap;

figure 4 shows a view of an end of the duct of a heat exchanger; and

figure 5 shows the section of the lower closure portion of the combustion chamber.

[0022] Making reference to figures 1 and 2, it is possible observing a heat exchanger 1 according to the present invention.

[0023] Said heat exchanger 1 provides a combustion chamber 2, within which spiral shaped duct 3' for water to be heated within the heat exchanger 3 is introduced.

[0024] Said heat exchanger 3 confers a substantially cylindrical shape to the combustion chamber.

[0025] Heat exchanger 3 has a water inlet duct and a water outlet duct, respectively indicated by reference number 4' and 4".

[0026] Burner 5 is provided substantially along the vertical axis of said combustion chamber 2, close to said burner 5 being provided the ignition spark plug 6 for ignition of the same burner 5.

[0027] A heat exchanger 3 cap - manifold 7 assembly is provided above said burner 5.

[0028] Heat exchanger 1 also provided on its base a lower cap 8, while a containment wall is provided laterally.

[0029] Said cap - manifold assembly and said lower cap 8, coupled by adjustable tie rods 10 acting on their edged, are provided, respectively, at the base of said cylindrical element 9. This assembling mode is particularly efficient and cheap, also permitting maintaining the heat exchanger duct 3' spiral compressed.

[0030] Cap - manifold 7 assembly is comprised of two parts: cap 7' and manifold element 7".

[0031] Cap 7' is comprised of metal, preferably aluminium, or any other heat conducting material. It has a substantially flat surface and it is in contact with the last turn of heat exchanger 3 duct 3'.

[0032] Manifold element 7" is preferably comprised of aluminium or plastic material. It is provided above said cap 7' and has such a dimension to cover the whole cap 7' surface.

[0033] Said collector 7" has a concave shape and is coupled with said cap 7', realising, along with the same, a cavity 11. Said cavity permits a first thermal insulation from heat irradiated from cap 7' and burner 5. then, air - gas mixture enters within said cavity 11 for supplying burner 5. said mixture has a temperature much lower than the temperature inside the combustion chamber. Thus, cavity 11 realised by cap 7' and manifold 7", at the same time cools said cap 7' and realises a thermal insulation.

[0034] As already said, this arrangement permits use of standard sealing gaskets, preventing the need of using refractory materials.

[0035] Both cap 7' and lower cap 8 are shaped so as to have an outlet structure for the spiral end from housing comprised of the two caps and the cylindrical element 9. It must be taken into consideration that in the art usually the ends of heat exchanger 3 duct 3' exit through the cylindrical element 9, thus creating problems for sealing and weldings.

[0036] Instead, by the exit through the caps it is possible obtaining a safe sealing without weldings.

[0037] The above permits eliminating problems due to the exit of said heat exchanger 3 duct 3' ends, particularly with respect to the installation of heat exchanger 1. In fact, coupling of caps 7' and 8 is such to permit their rotation. Thus, position of the duct 3' spiral ends can be conveniently varied.

[0038] Figure 3 shows heat exchanger 3 that in the embodiment shown is a spiral exchanger. Heat exchanger 3 duct 3' has annular slots 12 (see figure 4) on its ends, permitting the coupling without the need of weldings, only by a joint with gaskets (not shown in the figures).

[0039] Lower cap 8 is preferably comprised of plastics, aluminium or other metal. Heat exchanger 1 has under said cap 8 a discharge manifold 13 that can be comprised of plastics, aluminium or other metal.

[0040] Finally, figure 5 shows a section of lower closure of combustion chamber 3, wherein a steel disk 14 is placed, having such a shape to be inserted between gaps of a heat exchanger 3 tube turn, above which a heat insulating refractory 15 is provided.

[0041] On the basis of the previous specification it can be observed that basic advantage of the present invention is that of limiting the use of refractory insulating materials for insulation of heat irradiated from the boiler burner.

[0042] A further advantage of the present invention is the fact of permitting an easy, convenient and modular assembling.

[0043] The present invention has been described for illustrative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.

Claims

1. Boiler (1) comprising:

a water inlet duct (4') and a water outlet duct (4"), between which a heat exchanger (3) is provided, comprised of a helicoidal duct (3') through which water to be heated passes;

a combustion chamber (2) defined laterally by said heat exchanger (3) within which a burner (5) is provided, said burner (5) being supplied by an air-gas mixture; and

an upper cap (7'), having an upper and a lower surface, placed so said lower surface is in touch with at least the uppermost turn of the heat exchanger duct (3'), and a lower cap (8) spaced apart from the lowermost turn of the heat exchanger duct (3'), so as to create a gap for passage of gas and discharge condensate;

characterized in that it comprises:

a manifold element (7") being placed above said upper cap (7') and having such a dimension to cover the whole of said upper surface of said upper cap (7') and having a concave shape so that it realizes with said upper surface of said upper cap (7') a cavity (11) within which an air - gas mixture is collected before being conveyed within said burner (5) so as to form an insulation from the heat irradiated from said upper cap (7') and said burner (5);

a metal disk (14), shaped to be internally engaged within said heat exchanger (3) by internal screwing engagement with the turns of its duct (3'); and

an insulating refractory element (15) provided above said metallic disk (14), said insulating refractory element (15) and said metallic disk (14) being placed below said burner (5).

2. Boiler (1) according to claim 1, characterized in that said upper cap has a substantially flat upper surface.

3. Boiler (1) according to one of the preceding claims, characterized in that said manifold element (7") is comprised of metal, preferably aluminium.

4. Boiler (1) according to claim 1 or 2, characterized in that said manifold element (7") is comprised of plastic material.

5. Boiler (1) according to one of the preceding claims, characterized in that said cap (7') is coupled with said manifold element (7").

6. Boiler (1) according to one of the preceding claims, characterized in that coupling each other of said cap (7') and said manifold element (7") is adjusted by rotation.

7. Boiler (1) according to one of the preceding claims, characterized in that said disk (14) is comprised of steel.

8. Boiler (1) according to one of the preceding claims, characterized in that said duct (3') of said heat exchanger (3) comprises an annular slot (12) on each end, permitting the coupling with said inlet (4') and outlet (4") ducts without any welding.

9. Boiler (1) according to one of the preceding claims, characterized in that said heat exchanger (3) comprises a cylindrical element (9) between said upper cap (7') and said lower cap (8).

10. Boiler (1) according to one of the preceding claims, characterized in that said heat exchanger (3) comprises a plurality of tie rods (10), each provided with means for fixing at their ends with said upper cap (7') and with said lower cap (8).

11. Boiler (1) according to one of the preceding claims, characterized in that said upper cap (7') with gas manifold element (7") and said lower cap (8) with discharge collector are respectively realized integrally each other.

12. Boiler (1) according to one of the preceding claims, characterized in that said upper cap (7') with gas manifold element (7") and said lower cap (8) with discharge collector are realized separated from each other.

Ansprüche

1. Erhitzer (1), umfassend:

eine Wasser-Einlassleitung (4') und eine Wasser-Auslassleitung (4"), zwischen denen ein Wärmetauscher(3) vorgesehen ist, umfassend eine helikoidale Leitung (3'), durch die zu erwärmendes Wasser hindurchtritt;

eine Verbrennungskammer (2), die lateral durch den Wärmetauscher (3) definiert ist, in der ein Brenner (5) vorgesehen ist, wobei der Brenner (5) mit einem Luft-Gas-Gemisch versorgt wird; und

eine obere Abdeckung (7'), aufweisend eine obere und eine untere Oberfläche, platziert, so dass die untere Oberfläche in Berührung mit mindestens der obersten Windung der Wärmetauscher-Leitung (3') ist, und eine untere Abdeckung (8), die von der untersten Wicklung der Wärmetauscher-Leitung (3') beabstandet ist, um so eine Lücke für den Durchtritt von Gas und Auslass von Kondensat zu erzeugen;

dadurch gekennzeichnet, dass er umfasst:

ein Anschlusselement (7"), das über der oberen Abdekkung (7') platziert und eine derartige Dimension aufweist, um das Gesamte der oberen Oberfläche der oberen Abdeckung (7') zu bedecken, und eine konkave Form aufweist, so dass es mit der oberen Oberfläche der oberen Abdeckung (7') einen Hohlraum (11) bildet, in dem ein Luft-Gas-Gemisch gesammelt wird, bevor es in den Brenner (5) geleitet wird, um so eine Isolation von der Wärme zu bilden, die von der oberen Abdeckung (7') und dem Brenner (5) gestrahlt wird;

eine metallische Scheibe (14), die geformt ist, um im Innern in dem Wärmetauscher (3) durch inneren Schraubeingriff mit den Windungen von seiner Leitung (3') in Eingriff zu stehen; und

ein isolierendes Feuerfest-Element (15), das oberhalb der metallischen Scheibe (14) vorgesehen ist, wobei das isolierende Feuerfest-Element (15) und die metallische Scheibe (14) unterhalb des Brenners (5) platziert sind.

2. Erhitzer (1) gemäß Anspruch 1, dadurch gekennzeichnet, dass die obere Abdeckung eine im Wesentlichen flache obere Oberfläche aufweist.

3. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass das Anschluss-Element (7") Metall, vorzugsweise Aluminium umfasst.

4. Erhitzer (1) gemäß Anspruch 1 oder 2, dadurch gekennzeichnet, dass das Anschluss-Element (7") Kunststoffmaterial umfasst.

5. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die Abdeckung (7') mit dem Anschluss-Element (7") verbunden ist.

6. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass eine gegenseitige Verbindung der Abdeckung (7') und des Anschluss-Elements (7") durch Drehung justiert ist.

7. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die Scheibe (14) Stahl umfasst.

8. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die Leitung (3') des Wärmetauschers (3) an jedem Ende einen ringförmigen Schlitz (12) umfasst, die Verbindung mit den Einlass-(4')- und Auslass-(4")- Leitungen ohne jegliches Schweißen erlaubend.

9. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der Wärmetauscher (3) ein zylindrisches Element (9) zwischen der oberen Abdeckung (7') und der unteren Abdeckung (8) umfasst.

10. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der Wärmetauscher (3) eine Vielzahl von Verbindungs-Stäben (10) umfasst, von denen jeder mit Mitteln zum Fixieren an deren Enden mit der oberen Abdeckung (7') und mit der unteren Abdeckung (8) versehen ist.

11. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die obere Abdeckung (7') mit dem Gas-Anschluss-Element (7") und die untere Abdeckung (8) mit einem Auslass-Sammler entsprechend einander integral gebildet sind.

12. Erhitzer (1) gemäß einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die obere Abdeckung (7') mit dem Gas-Anschluss-Element (7") und die untere Abdeckung (8) mit dem Auslass-Sammler voneinander getrennt gebildet sind.

Revendications

1. Chaudière (1) comprenant :

une conduite d'entrée d'eau (4') et une conduite de sortie d'eau (4"), entre lesquelles est disposé un échangeur de chaleur (3) constitué d'une conduite hélicoïdale (3') dans laquelle circule l'eau à chauffer ;

une chambre de combustion (2), définie latéralement par ledit échangeur de chaleur (3) et dans laquelle est disposé un brûleur (5), ledit brûleur (5) étant alimenté en un mélange air - gaz ; et

un capot supérieur (7'), ayant une surface supérieure et une surface inférieure, placé de telle sorte que ladite surface inférieure soit en contact avec au moins la spire la plus haute de la conduite (3') de l'échangeur de chaleur, et un capot inférieur (8) espacé de la spire la plus basse de la conduite (3') de l'échangeur de chaleur de façon à créer un espace pour le passage du gaz et l'écoulement du condensat ;

caractérisée en ce qu'elle comprend :

un élément collecteur (7") placé au-dessus dudit capot supérieur (7'), ayant une dimension telle qu'il recouvre la totalité de la surface supérieure dudit capot supérieur (7') et présentant une forme concave de façon à former avec ladite surface supérieure dudit capot supérieur (7') une cavité (11) à l'intérieur de laquelle un mélange air - gaz est collecté avant d'être transporté à l'intérieur dudit brûleur (5), de façon à former une isolation par rapport à la chaleur rayonnée par ledit capot supérieur (7') et ledit brûleur (5) ;

un disque métallique (14), conformé pour être mis en prise intérieurement avec ledit échangeur de chaleur (3), par vissage intérieur dans les spires de sa conduite (3') ; et

un élément réfractaire isolant (15) disposé au-dessus dudit disque métallique (14), ledit élément réfractaire isolant (15) et ledit disque métallique (14) étant placés en dessous dudit brûleur (5).

2. Chaudière (1) selon la revendication 1, caractérisée en ce que ledit capot supérieur a une surface supérieure sensiblement plate.

3. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que ledit élément collecteur (7") est fait de métal, de préférence d'aluminium.

4. Chaudière (1) selon la revendication 1 ou 2, caractérisée en ce que ledit élément collecteur (7") est fait de matière plastique.

5. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que ledit capot (7') est accouplé audit élément collecteur (7").

6. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que l'accouplement mutuel dudit capot (7') et dudit élément collecteur (7") est ajusté par rotation.

7. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que ledit disque (14) est fait d'acier.

8. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que ladite conduite (3') dudit échangeur de chaleur (3) comporte une rainure annulaire (12) à chaque extrémité, permettant ainsi le raccordement auxdites conduites d'entrée (4') et de sortie (4") sans soudure.

9. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que ledit échangeur de chaleur (3) comprend un élément cylindrique (9) entre ledit capot supérieur (7') et ledit capot inférieur (8).

10. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que ledit échangeur de chaleur (3) comprend une pluralité de tringles d'assemblage (10), dont chacune est munie à ses extrémités de moyens de fixation audit capot supérieur (7') et audit capot inférieur (8).

11. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que ledit capot supérieur (7') avec l'élément collecteur de gaz (7"), et ledit capot inférieur (8) avec le collecteur d'écoulement sont respectivement réalisés sous la forme d'ensembles d'un seul tenant.

12. Chaudière (1) selon une des revendications précédentes, caractérisée en ce que ledit capot supérieur (7') avec l'élément collecteur de gaz (7") et ledit capot inférieur (8) avec le collecteur d'écoulement, sont réalisés sous la forme d'ensembles séparés l'un de l'autre..

Drawing