EP0092010A1 - Shaping of tubes having a turbulence effect for heat exchangers - Google Patents
Shaping of tubes having a turbulence effect for heat exchangers Download PDFInfo
- Publication number
- EP0092010A1 EP0092010A1 EP82400670A EP82400670A EP0092010A1 EP 0092010 A1 EP0092010 A1 EP 0092010A1 EP 82400670 A EP82400670 A EP 82400670A EP 82400670 A EP82400670 A EP 82400670A EP 0092010 A1 EP0092010 A1 EP 0092010A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- tube
- knurling
- knurls
- barrel
- shaping
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D15/00—Corrugating tubes
- B21D15/04—Corrugating tubes transversely, e.g. helically
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
- F28F1/42—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being both outside and inside the tubular element
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
- F28F1/42—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being both outside and inside the tubular element
- F28F1/424—Means comprising outside portions integral with inside portions
- F28F1/426—Means comprising outside portions integral with inside portions the outside portions and the inside portions forming parts of complementary shape, e.g. concave and convex
Definitions
- the present invention relates to the shaping of thin single or double wall tubes, made of ferrous and non-ferrous metals intended for the manufacture of heat exchangers and other fluid transfer systems with helical or turbulent stirring.
- it relates to a helical or annular knurling process on the passing of a thin-walled tube on a standard cold forming machine with two knurls, according to which the tube subjected to knurling is driven by the knurls along a circular guide.
- the main object of the invention is to provide a shaping process which can be carried out under economical conditions and which also guarantees the accuracy of the profiles sought.
- the method according to the invention consists in using as a circular guide only an external cylindrical mandrel or "barrel” whose solid wall is notched opposite the knurls and in attacking the tube using the wheels through these notches.
- the method according to the invention also consists in imparting a rough surface to the tube by giving an appropriate surface state to the knurls.
- This surface roughness forms mini-cavities which increase the heat exchange surface.
- these mini-cavities cause, in the refrigerant gas circulating outside the tube, turbulence favorable to heat exchange with the water circulating inside the tube.
- the method also makes it possible to shape, at the same time, two tubes of neighboring diameters engaged one inside the other to obtain a double-walled tube.
- the double-walled tube that can be produced according to the invention perfectly meets this requirement.
- the "barrel” comprises, at its lower part, a rigid support 13 making it integral with the frame 14 of the machine.
- each wheel 1 and 2 The entire working surface of each wheel 1 and 2 is treated by the so-called shot-blasting process in order to obtain micro-cavities 15 which give the wheel a rough appearance.
- the projecting parts of the working area of each wheel 1 and 2 have ridges 16 obtained by a knurling operation.
- the end of the tube 7 is introduced into the part 8 of the barrel while the knobs 1 and 2 rotate about their respective axes xx and yy.
- the tube 7 comes into contact with the knobs 1 and 2, which penetrate inside the barrel, by the notches made in the central part 10 of the latter, the periphery of said tube is successively attacked by the profiles 3, 4 , 6 and 5, which drive the tube in rotation and make it progress towards part 9 of the barrel, by printing the desired imprint there.
- the rotary drive is improved by the roughness and the striations of the working surface of the knobs 1 and 2, in the sense that any slipping of the tube is avoided so as to cause an overlap of the shaped propellers and a " stuffing" of the tube 7, blocking the latter in rotation.
- the shaped tube 7 emerges from the machine, guided by the part 9 of the barrel. It has, according to the profile given to the knobs 1 and 2, a deep annular or helical imprint and its periphery weakly reproduces the streaks and roughness of the working surface of the knobs, in the form of corresponding streaks and micro-cavities. These give the tube a surface condition suitable for improving heat exchange (heat exchangers) because the exchange surface obtained with this system is larger than that of a smooth tube with the same dimensional characteristics.
- the method according to the invention essentially derives its originality from the modes of guiding and driving the tube to be shaped which allows try to shape in a single pass helical or annular impressions on single or double wall tubes without length limitation, while limiting the rolling of the metal and the alteration of its primitive physical qualities.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Geometry (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
Abstract
Description
La présente invention concerne le façonnage de tubes minces à simple ou double paroi, en métaux ferreux et non ferreux destinés àla fabrication d'échangeurs de chaleur et autres systèmes de transfert de fluides avec brassage hélicoïdal ou turbulent.The present invention relates to the shaping of thin single or double wall tubes, made of ferrous and non-ferrous metals intended for the manufacture of heat exchangers and other fluid transfer systems with helical or turbulent stirring.
Plus précisément, elle a pour objet un procédé de moletage hélicoïdal ou annulaire au défilé d'un tube à paroi mince sur machine standard de formage à froid à deux molettes, selon lequel le tube soumis au moletage est entraîné par les molettes le long d'un guide circulaire.More specifically, it relates to a helical or annular knurling process on the passing of a thin-walled tube on a standard cold forming machine with two knurls, according to which the tube subjected to knurling is driven by the knurls along a circular guide.
Différents procédés ont été proposés jusqu'ici pour la réalisation de tels tubes mais aucun d'eux ne donne entière satisfaction, soit qu'ils ne sont applicables qu'à des tubes de diamètre et de longueur limités, soit qu'ils ne permettent pas un façonnage en continu, soit qu'ils sont inaptes à la réalisation de rainures annulaires ou d'empreintes ayant le profil exact souhaité, soit qu'ils nécessitent des investissements importants pour la création de machines spécifiquement destinées à la fabrication en cause, à savoir des machines sophistiquées utilisant quatre galets de façonnage.Different methods have been proposed so far for the production of such tubes but none of them is entirely satisfactory, either that they are applicable only to tubes of limited diameter and length, or that they do not allow continuous shaping, either because they are unsuitable for producing annular grooves or impressions having the exact desired profile, or because they require significant investment for the creation of machines specifically intended for the production in question, namely sophisticated machines using four shaping rollers.
L'invention a pour but principal d'apporter un procédé de façonnage qui soit réalisable dans des conditions économiques et qui garantisse, en outre, l'exactitude des profils recherchés.The main object of the invention is to provide a shaping process which can be carried out under economical conditions and which also guarantees the accuracy of the profiles sought.
Ce but est atteint en ce sens que le procédé selon l'invention consiste à n'utiliser comme guide circulaire, qu'un mandrin ou "canon" cylindrique externe dont la paroi pleine est échancrée en vis à vis des molettes et à attaquer le tube à l'aide des molettes au travers de ces échancrures.This object is achieved in the sense that the method according to the invention consists in using as a circular guide only an external cylindrical mandrel or "barrel" whose solid wall is notched opposite the knurls and in attacking the tube using the wheels through these notches.
Ainsi, en n'adjoignant qu'un outillage simple à des machines standard dites de formage à froid à molettes, il est possible de réaliser :
- - un façonnage calibré, sans limitation de profondeur des ondulations et sans limitation du nombre d'hélices ;
- - un façonnage de tubes cuivre ou acier de toutes épaisseurs et de tous diamètres, sans problèmes spécifiques pour les tubes à parois minces ;
- - un façonnage en continu, sans restriction de longueur et sans besoin d'outillage spécial annexe, tel que barre de traction ;
- - un façonnage de rainures hélicoïdales ou annulaires, en procédant de la même manière et sans opération supplémentaire ,
ce que ne permet aucun procédé antérieur.Thus, by adding only simple tools to standard machines known as cold roll forming machines, it is possible to achieve:
- - calibrated shaping, without limiting the depth of the undulations and without limiting the number of propellers;
- - shaping of copper or steel tubes of all thicknesses and all diameters, without specific problems for thin-walled tubes;
- - continuous shaping, without length restriction and without the need for special additional tools, such as a drawbar;
- - shaping of helical or annular grooves, in the same way and without additional operation,
which no previous process allows.
Dans un mode de mise en oeuvre préféré, le procédé selon l'invention consiste, en outre, à conférer une surface rugueuse au tube en donnant un état de`surface approprié aux molettes.In a preferred embodiment, the method according to the invention also consists in imparting a rough surface to the tube by giving an appropriate surface state to the knurls.
Cette rugosité de surface forme des mini-cavités qui augmentent la surface d'échange thermique. Ainsi, par exemple, dans les échangeurs gaz refrigérant/eau, ces mini-cavités provoquent, dans le gaz réfrigérant circulant à l'extérieur du tube, des turbulences favorables à l'échange thermique avec l'eau qui circule à l'intérieur du tube.This surface roughness forms mini-cavities which increase the heat exchange surface. Thus, for example, in the refrigerant gas / water exchangers, these mini-cavities cause, in the refrigerant gas circulating outside the tube, turbulence favorable to heat exchange with the water circulating inside the tube.
Selon l'invention, les deux typés de forme façonnées, à savoir :
- - les rainures hélicoïdales ou annulaires, et
- - les aspérités externes bénéfiques aux échanges de chaleur,
peuvent être réalisées simultanément.According to the invention, the two types of shaped shape, namely:
- - the helical or annular grooves, and
- - external roughness beneficial to heat exchange,
can be performed simultaneously.
Le procédé permet, en outre, de façonner, en même temps, deux tubes de diamètres voisins engagés l'un dans l'autre pour obtenir un tube double paroi.The method also makes it possible to shape, at the same time, two tubes of neighboring diameters engaged one inside the other to obtain a double-walled tube.
Ce genre de fabrication trouve son importance dans les échangeurs thermiques spéciaux utilisés dans la production d'eau chaude potable et qui emploient un fluide vecteur (caloporteur).This type of manufacturing finds its importance in special heat exchangers used in the production of potable hot water and which use a carrier fluid (heat transfer fluid).
En effet, en France potamment, ces échangeurs doivent répondre à des normes de sécurité qui stipulent que la perforation de l'enveloppe du fluide vecteur ne doit, en aucun cas, permettre le contact entre ce fluide et l'eau potable et que la détérioration du dispositif d'échange doit se manifester de façon visible à l'extérieur de ce dispositif.Indeed, in France potentially, these exchangers must meet safety standards which state that the perforation of the envelope of the carrier fluid must in no case allow contact between this fluid and drinking water and that deterioration of the exchange device must be visible in the outside of this device.
Le tube à double paroi réalisable selon l'invention répond parfaitement à cette exigence.The double-walled tube that can be produced according to the invention perfectly meets this requirement.
L'invention est décrite par référence aux dessins annexés dans lequels :
- - la figure 1 est une vue de dessus en coupe partielle de l'outillage tel qu'il est monté sur une machine de formage à froid par molettes,
- - la figure 2 est une vue en coupe prise selon la ligne AA ou BB de la figure 1,
- - la figure 3 est une vue en coupe prise selon la ligne CC de la figure 1,
- - la figure 4 est une vue en perspective à plus grande échelle de la surface du tube après façonnage, et
- - la figure 5 est une vue similaire à la figure 3, montrant à plus grande échelle l'attaque des molettes sur le tube.
- - Figure 1 is a top view in partial section of the tool as it is mounted on a forming machine cold by wheels,
- FIG. 2 is a sectional view taken along the line AA or BB of FIG. 1,
- FIG. 3 is a sectional view taken along line CC of FIG. 1,
- FIG. 4 is a perspective view on a larger scale of the surface of the tube after shaping, and
- - Figure 5 is a view similar to Figure 3, showing on a larger scale the attack of the rollers on the tube.
Si l'on se réfère aux figures 1, 3 et 5, on voit que le dispositif utilisé pour la mise en oeuvre du procédé selon l'invention comporte deux molettes de formage motorisées 1 et 2 traditionnellement montées sur deux axes parallèles xx, yy dans un plan vertical, lesquelles molettes présentent :
- - une zone conique de déformation progressive 3,
- - une zone cylindrique de calibrage 4
- - une zone conique de dégagement 5, et
- - un profil usiné 6 correspondant exactement au profil souhaité sur le tube à façonner 7.
- - a conical zone of progressive deformation 3,
- - a cylindrical calibration zone 4
- - a conical clearance zone 5, and
- - a
machined profile 6 corresponding exactly to the desired profile on the tube to be shaped 7.
L'inclinaison en degrés de l'hélice réalisée sur chaque molette 1 et 2 est peu différente de l'angle d'hélice alpha α souhaité sur le tube à façonner 7.The inclination in degrees of the helix produced on each
Il est prévu, pour le tube 7, un guide circulaire se présentant sous la forme d'un mandrin ou "canon" 8-12 monobloc très rigide
- - qui est situé dans un plan horizontal, entre les deux
1, 2molettes - - dont les parties "amont" 8 et "aval" 9 entourent le
tube 7 respectivement à son entrée dans, et à sa sortie de, la machine, et - - qui est échancré dans sa partie centrale 10 en vis à vis des
molettes 1 et 2, permettant ainsi à ces dernières d'at- teindre letube 7 à déformer.
- - which is located in a horizontal plane, between the two
1, 2knobs - - whose "upstream" 8 and "downstream" 9 parts surround the
tube 7 respectively when it enters, and when it leaves, the machine, and - - which is indented in its
central part 10 opposite the 1 and 2, thus allowing the latter to reach theknobs tube 7 to be deformed.
Les deux parties 11 et 12 du "canon" de guidage subsistant dans la zone centrale 10 assurent un maintien énergique du tube 7 en cours de façonnage, limitant ainsi au maximum l'ovalisation de ce dernier sous l'action de quatre forces concentriques qui s'équilibrent (figure 3) :
- - F1 et F2 = actions des molettès
- - F3 et F4 = actions du "canon" de guidage.
- - F1 and F2 = knurling actions
- - F3 and F4 = actions of the guide "cannon".
Comme il ressort des figures 2 et 3, le "canon" comporte, à sa partie inférieure, un support rigide 13 le rendant solidaire du bâti 14 de la machine.As is apparent from Figures 2 and 3, the "barrel" comprises, at its lower part, a
Toute la surface de travail de chaque molette 1 et 2 est traitée par le procédé dit de grenaillage afin d'obtenir des micro-cavités 15 qui conférent à la molette un aspect rugueux. De plus, les parties saillantes de la zone de travail de chaque molette 1 et 2 présentent des stries 16 obtenues par une opération de moletage.The entire working surface of each
Le fonctionnement du dispositif est le suivant :The operation of the device is as follows:
On introduit l'extrémité du tube 7 dans la partie 8 du canon tandis que tournent les molettes 1 et 2 autour de leur axe respectif xx et yy. Lorsque le tube 7 entre en contact avec les molettes 1 et 2, qui pénètrent à l'intérieur du canon, par les échancrures pratiquées dans la partie centrale 10 de ce dernier, la périphérie dudit tube se trouve successivement attaquée par les profils 3, 4, 6 et 5, qui entraînent le tube en rotation et le font progresser vers la partie 9 du canon, en y imprimant l'empreinte voulue. L'entraînement en rotation est amélioré par la rugosité et les striages de la surface de travail des molettes 1 et 2, en ce sens que l'on évite tout glissement du tube de nature à provoquer un chevauchement des hélices façonnées et un "bourrage" du tube 7, bloquant ce dernier en rotation.The end of the
Le tube 7 façonné ressort de la machine, guidé par la partie 9 du canon. Il présente, selon le profil conféré aux molettes 1 et 2, une empreinte annulaire ou hélicoïdale profonde et sa périphérie reproduit faiblement les stries et rugosités de la surface de travail des molettes, sous la forme de stries et de micro-cavités correspondantes. Celles-ci confèrent au tube un état de surface propre à améliorer les échanges thermiques (échangeurs de chaleur) car la surface d'échange obtenue avec ce système est plus importante que celle d'un tube lisse de mêmes caractéristiques dimensionnelles.The shaped
De plus, ces rugosités provoquent des mini-turbulences au niveau de l'écoulement du fluide en contact avec cette surface amenant ainsi un coefficient d'échange thermique supérieur.In addition, these roughnesses cause mini-turbulence at the level of the flow of the fluid in contact with this surface thus bringing a higher coefficient of heat exchange.
Comme il ressort de la description ci-dessus, le procédé selon l'invention tire essentiellement son originalité des modes de guidage et d'entraînement du tube à façonner qui permettent de façonner en une seule passe des empreintes hélicoïdales ou annulaires sur des tubes à simple ou double paroi sans limitation de longueur, tout en limitant le laminage du métal et l'altération de ses qualités physiques primitives.As emerges from the description above, the method according to the invention essentially derives its originality from the modes of guiding and driving the tube to be shaped which allows try to shape in a single pass helical or annular impressions on single or double wall tubes without length limitation, while limiting the rolling of the metal and the alteration of its primitive physical qualities.
Claims (6)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP82400670A EP0092010A1 (en) | 1982-04-15 | 1982-04-15 | Shaping of tubes having a turbulence effect for heat exchangers |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP82400670A EP0092010A1 (en) | 1982-04-15 | 1982-04-15 | Shaping of tubes having a turbulence effect for heat exchangers |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0092010A1 true EP0092010A1 (en) | 1983-10-26 |
Family
ID=8189900
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP82400670A Withdrawn EP0092010A1 (en) | 1982-04-15 | 1982-04-15 | Shaping of tubes having a turbulence effect for heat exchangers |
Country Status (1)
Country | Link |
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EP (1) | EP0092010A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0274719A2 (en) * | 1987-01-13 | 1988-07-20 | Gd-Anker Gmbh | Thread-forming method and tubular body provided with a thread |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE55042C (en) * | L. GObiet und L. carrer in Düsseldorf, Feldstr. 31 bezw. Immermannstr. 17 | Rolling device for the production of helically corrugated heating tubes | ||
FR1118390A (en) * | 1954-02-01 | 1956-06-05 | Gen Electric Co Ltd | Method and machine for corrugating helical tubes |
GB791513A (en) * | 1954-02-01 | 1958-03-05 | Pirelli General Cable Works | Improvements in or relating to machines and methods for corrugating electric cable sheaths |
US3387477A (en) * | 1965-11-29 | 1968-06-11 | Price Pfister Brass Mfg | Apparatus and method for roll forming flexible tubing |
US3538728A (en) * | 1966-05-16 | 1970-11-10 | Johns Manville | Method and apparatus for producing flexible metal ducts |
DE2517249A1 (en) * | 1975-04-18 | 1976-10-28 | Kabel Metallwerke Ghh | Heat exchanger tube with helical corrugations - with smaller corrugations superimposed to increase turbulence |
-
1982
- 1982-04-15 EP EP82400670A patent/EP0092010A1/en not_active Withdrawn
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE55042C (en) * | L. GObiet und L. carrer in Düsseldorf, Feldstr. 31 bezw. Immermannstr. 17 | Rolling device for the production of helically corrugated heating tubes | ||
FR1118390A (en) * | 1954-02-01 | 1956-06-05 | Gen Electric Co Ltd | Method and machine for corrugating helical tubes |
GB791513A (en) * | 1954-02-01 | 1958-03-05 | Pirelli General Cable Works | Improvements in or relating to machines and methods for corrugating electric cable sheaths |
US3387477A (en) * | 1965-11-29 | 1968-06-11 | Price Pfister Brass Mfg | Apparatus and method for roll forming flexible tubing |
US3538728A (en) * | 1966-05-16 | 1970-11-10 | Johns Manville | Method and apparatus for producing flexible metal ducts |
DE2517249A1 (en) * | 1975-04-18 | 1976-10-28 | Kabel Metallwerke Ghh | Heat exchanger tube with helical corrugations - with smaller corrugations superimposed to increase turbulence |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0274719A2 (en) * | 1987-01-13 | 1988-07-20 | Gd-Anker Gmbh | Thread-forming method and tubular body provided with a thread |
EP0274719A3 (en) * | 1987-01-13 | 1989-12-20 | Gd-Anker Gmbh | Thread-forming method and tubular body provided with a thread |
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