(19)
(11) EP 0 676 597 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
24.11.1999 Bulletin 1999/47

(21) Application number: 95830078.2

(22) Date of filing: 06.03.1995
(51) International Patent Classification (IPC)6F24H 9/00, F28F 13/00

(54)

Pipe assembly for conveying fumes in steel boilers provided with condensate quick evaporating means

Rohreinheit zum Fördern von Rauchgas in Stahlheizkesseln mit Mitteln zum schnellen Verdampfen von Kondensat

Assemblage de tuyaux pour guider les fumées dans des chaudières en acier avec moyens pour évaporer rapidement les condensations


(84) Designated Contracting States:
AT BE CH DE DK ES FR GB IE LI NL PT

(30) Priority: 06.04.1994 IT MI940248 U

(43) Date of publication of application:
11.10.1995 Bulletin 1995/41

(73) Proprietor: FERROLI S.p.A.
I-37047 San Bonifacio (Verona) (IT)

(72) Inventor:
  • Ferroli, Dante, c/o Ferroli S.P.A.
    I-37047 San Bonifacio VR (IT)

(74) Representative: Cicogna, Franco 
Ufficio Internazionale Brevetti Dott.Prof. Franco Cicogna Via Visconti di Modrone, 14/A
20122 Milano
20122 Milano (IT)


(56) References cited: : 
DE-A- 3 410 141
GB-A- 2 053 444
DE-A- 3 822 238
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND OF THE INVENTION



    [0001] The present invention relates to a pipe assembly for conveying fumes in steel boilers provided with condensate quick evaporating means.

    [0002] As is known, a problem to be solved in making boilers is that of the combustion product condensate formed in the fume conveying pipes and which causes a quick wear of the boilers.

    [0003] In particular, with respect to boilers made of steel, the lacking of fins, which can be hardly formed, greatly facilitates a collection of the condensate at cold regions.

    SUMMARY OF THE INVENTION



    [0004] Accordingly, the aim of the present invention is to solve the above mentioned problem, so as to reduce the condensate materials and facilitate an evaporation of said condensate materials, during the idle periods in the operation of the burner device associated with the boiler.

    [0005] Within the scope of the above mentioned aim, a main object of the present invention is to provide a fume conveying pipe assembly in which the surfaces contacting the fumes are cooled very slowly so as to facilitate the evaporation of possible condensate materials.

    [0006] Another object of the present invention is to provide such a fume conveying pipe assembly which is very reliable and safe in operation and which can be easily made starting from easily available elements and materials and which, moreover, is very competitive from a mere economic standpoint.

    [0007] According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a pipe assembly for conveying fumes in steel boilers provided with condensate quick evaporating means, said pipe assembly comprises an inner pipe and an outer pipe, which define a closed gap therebetween, characterized in that the outer pipe (3) comprises between said inner pipe and outer pipe parallel contacting lines extending which are made by drawing said outer pipe (3).

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0008] Further characteristics and advantages of the invention will become more apparent hereinafter from the following detailed disclosure of a pipe assembly for conveying fumes in steel boilers provided with-condensate quick evaporating means which is illustrated, by way of an indicative example in the figures of the accompanying drawings, where:

    Figure 1 is a perspective view illustrating the fume conveying pipe assembly according to the present invention;

    Figure 2 is an elevation view illustrating the fume conveying pipe assembly according to the invention;

    Figure 3 is a cross-longitudinal view illustrating the fume conveying pipe assembly of the invention; and

    Figure 4 is a cross-sectional view illustrating the fume conveying pipe assembly according to the invention.


    DESCRIPTION OF THE PREFERRED EMBODIMENT



    [0009] With reference to the number references of the above mentioned figures, the fume conveying pipe assembly, specifically designed for steel boilers provided with condensate quick evaporating means, according to the present invention, which has been generally indicated at the reference number 1, comprises an inner pipe 2 and an outer pipe 3, coaxial with respect to one another, and so arranged as to define a closed gap 4 therebetween.

    [0010] The inner pipe, at the end portions thereof, is enlarged so as to perfectly abut against the outer pipe, thereby said gap 4 is perfectly closed and has substantially an even thickness.

    [0011] The heat conduction between the inner pipe and outer pipe is obtained by contacting lines 10 extending with a helical pattern and which are obtained by a drawing on the outer pipe.

    [0012] The provision of the above mentioned gap allows to satisfactorily solve the condensate problem, since the air gap will reduce the generation of cool regions susceptible to favour the formation of condensate materials.

    [0013] Moreover, with respect to prior solutions, the contacting surface between the two pipes being the same, there will be obtained a smaller spacing of the contacting points, with a consequent greater heating speed or rate of the surfaces between the contacting points.

    [0014] This is very important since, as the burner associated with the boiler is disenergized, the mentioned surfaces will be cooled with a smaller rate and, accordingly, will facilitate the evaporation of the condensate material.

    [0015] From the above disclosure it should be apparent that the invention fully achieves the intended aim and objects.

    [0016] In particular, the fact is to be pointed out that, owing to the provision of the helical lines, it is greatly improved the operation of the fume conveying steel pipes used in the boilers.

    [0017] In practicing the invention, the used materials, as well as the contingent size and shapes can be any, depending on requirements and the scope of the claims.


    Claims

    1. A pipe assembly (1) for conveying fumes in steel boilers provided with condensate quick evaporating means, said pipe assembly (1) comprising an inner pipe (2) and an outer pipe (3), which define a closed gap (4) therebetween, characterized in that the outer pipe (3) comprises between said inner pipe (2) and outer pipe (3) parallel contacting lines (10) which are made by drawing said outer pipe (3).
     
    2. A pipe assembly (1) according to Claim 1, characterized in that said inner pipe (2) is enlarged at the end portions thereof, in order to tightly contact the outer pipe (3) and close said gap (4).
     


    Ansprüche

    1. Eine Rohreinheit (1), um Rauchgas in Stahlheizkesseln mit Vorrichtungen zum schnellen Verdampfen von Kondensat zu befördern, wobei diese Rohreinheit (1) ein inneres Rohr (2) und ein äußeres Rohr (3) umfaßt, die einen dazwischen liegenden, geschlossenen Spalt (4) festlegen, dadurch gekennzeichnet, daß das äußere Rohr (3) zwischen diesem inneren Rohr (2) und diesem äußeren Rohr (3) parallele Berührungslinien (10) aufweist, die beim Ziehen dieses äußeren Rohres (3) gefertigt werden.
     
    2. Eine Rohreinheit (1) nach Anspruch 1, dadurch gekennzeichnet, daß sich dieses innere Rohr (2) an seinen Endbereichen verbreitert, wodurch es das äußere Rohr (3) dicht berührt und diesen Spalt (4) verschließt.
     


    Revendications

    1. Assemblage de tuyaux (1) pour pour guider les fumées dans des chaudières en acier avec des moyens pour l'évaporation rapide de la condensation, ledit assemblage de tuyaux (1) comprenant un tuyau intérieur (2) et un tuyau extérieur (3), qui définissent entre eux un intervalle fermé (4), caractérisé en ce que le tuyau extérieur (3) comprend entre lesdits tuyau intérieur (2) et tuyau extérieur (3) des lignes de contact (« contacting lines ») parallèles (10) qui sont réalisées par étirage (« drawing ») dudit tuyau extérieur (3).
     
    2. Assemblage de tuyaux (1) selon la revendication 1, caractérisé en ce que ledit tuyau intérieur (2) est élargi en ses portions d'extrémités, pour être en contact hermétique avec le tuyau extérieur (3) et fermer ledit intervalle (4).
     




    Drawing