CH540771A

CH540771A - Extruded plastic pipe cooler - using partial immersion in bath

Info

Publication number: CH540771A
Application number: CH450071A
Authority: CH
Inventors: Krieger Lutz
Original assignee: Sig Schweiz Industrieges
Priority date: 1971-03-26
Filing date: 1971-03-26
Publication date: 1973-08-31

Abstract

Cooler bath is a horizontal curved bottom trough set such a height that the pipe leaving the nozzle floats on the coolant surface without bending. A pair of symmetrical axially parallel troughs above the pipe are fed at such a rate that the liq. trickling over their weirs onto the apex of the pipe, flows down to cool the upper surfaces in the form of a liq. film. Relatively high extrusion speeds are possible without damage to the pipe.

Description

  

  
 



   La présente invention a pour objet, d'une part, un procédé pour refroidir un extrudat tubulaire et, d'autre part, une installation pour la mise en   oeuvre    de ce procédé.



   Le procédé est caractérisé en ce qu'on fait passer cet extrudat dans un bain de liquide réfrigérant en le laissant flotter librement sur ce bain, en ce qu'on fixe le niveau de ce bain pour maintenir l'extrudat flottant en position sensiblement coaxiale à l'axe d'extrusion, et en ce qu'on forme un écoulement de ce liquide sur la partie flottante de la face externe de   l'extrudat    par déversement du liquide sur la portion la plus élevée de cette face.



   L'installation se caractérise en ce qu'elle comprend une source de liquide réfrigérant, un bac destiné à contenir ledit bain et présentant une profondeur suffisante pour permettre la flottaison de l'extrudat, au moins un déversoir agencé et disposé de manière à permettre le déversement de liquide sur la portion la plus élevée de l'extrudat flottant sur le bain du bac et des moyens pour assurer l'alimentation du bac et du déversoir en liquide réfrigérant provenant de ladite source.



   Le dessin annexé représente, à titre d'exemple et très schématiquement, une forme d'exécution d'une installation pour la mise en oeuvre du procédé selon l'invention:
 la fig. 1 en est une coupe longitudinale simplifiée;
 la fig. 2 est une coupe, à plus grande échelle, selon II-II de la fig. 1.



   L'installation représentée est destinée à assurer le refroidissement d'un extrudat tubulaire 1 produit en continu par une filière 2 d'une extrudeuse 3 dont seule l'extrémité aval du cylindre est visible au dessin, cet extrudat étant soumis à une traction en direction F grâce à un dispositif non représenté   tfig.    1).



   Cette installation comprend une enveloppe 4, qui est ouverte sur sa partie supérieure et dont le fond présente une ouverture 5 le long des bords de laquelle est fixée une tubulure 6. Les parois opposées 4A et 4B, de cette enveloppe, présentent chacune une fenêtre circulaire 7A et 7B. Ces deux fenêtres sont disposées coaxialement à l'axe d'extrusion de la filière 2 et leur diamètre est légèrement supérieur à celui de l'extrudat 1 produit par cette filière.



   Un joint annulaire 8A, respectivement 8B, est fixé sur la paroi 4A, respectivement 4B, tout autour de la fenêtre 7A, respectivement 7B. Ce joint, qui est en matériau souple, par exemple en matière plastique, est destiné à l'obturation de l'espace compris entre le bord de la fenêtre 7A, respectivement 7B, et la paroi externe de l'extrudat traversant la fenêtre 7A, respectivement 7B, lorsqu'il est soumis à la traction en direction F, mentionnée précédemment.



   A l'intérieur de l'enveloppe 4, l'installation comprend notamment un bac 9 (fig. 1 et 2) qui est constitué par un secteur d'une jupe cylindrique fixée sur la paroi 4A de l'en   xeloppe    4 (fig. 1), cette paroi constituant ainsi également la paroi gauche du bac, et le long du bord droit de laquelle est fixée une plaque 9A présentant la forme d'un secteur d'anneau dont le diamètre interne est légèrement supérieur au diamètre externe de l'extrudat 1, cette plaque 9A constituant la paroi droite du bac. Un joint semi-annulaire 10, fixé sur la face externe de la plaque 9A, obture le passage compris entre la partie arrondie du bord supérieur de cette plaque et l'extrudat.



   Ce bac 9 est en effet destiné à contenir un bain 11 de liquide réfrigérant qui est introduit en permanence dans le bac grâce à une tubulure 12 débouchant dans le fond du bac et rattachée à un conduit d'alimentation générale 13   aboutis-    saut à une source de liquide réfrigérant non représentée. Ce liquide peut par exemple être de l'eau.



   Comme l'alimentation du bac 9 en liquide est continue, et que, d'autre part, ce bac n'est muni d'aucun orifice de sortie, le liquide du bain 11 circule en permanence entre le fond du bac et ses bords et déborde de ce bac pour retomber dans l'enceinte 4.



   Ainsi que nous allons le voir, la capacité de liquide débordant du bac 9 est, à chaque instant, supérieure à la quantité de liquide amenée à ce bac par le conduit 12.



   En effet, en plus du bac 9, l'installation représentée comprend également un second bac 14 subdivisé en deux réservoirs 14A et 14B à chacun desquels est associé un déversoir   15A,    respectivement 15B, et qui sont alimentés en liquide de réfrigération, à partir des conduits 13, par l'intermédiaire de tubulures de raccord 16A et 16B. Le bac 14 présente une longueur sensiblement identique à celle du bac 9 et est disposé au-dessus de celui-ci, symétriquement de part et d'autre de son plan médian, à un niveau suffisant pour permettre à un extrudat de la dimension de celui illustré au dessin de flotter librement sur le bain 11 sans entrer en contact avec le bac 14.



   Grâce à l'installation décrite, il est possible de refroidir tout profilé tubulaire produit par une extrudeuse, au fur et à mesure de l'extrusion, sans devoir guider et tenir ce profilé par des moyens mécaniques prenant appui sur la face externe du profilé, ce qui élimine donc le risque éventuel de déformations non désirées du profilé.



   En effet, avec cette installation, le produit extrudé est maintenu à un même niveau, correspondant sensiblement à celui auquel a eu lieu l'extrusion, pendant toute l'opération de refroidissement, et cela parce que cette opération s'effectue alors que l'extrudat flotte librement sur le bain 11 du bac 9, lequel bac est évidemment disposé à la hauteur voulue, compte tenu du poids propre de l'extrudat, du poids spécifique du liquide de refroidissement utilisé, et de la hauteur de liquide déplacé par cet extrudat en état de flottaison.



   Le refroidissement est naturellement aussi effectué par le liquide du bain 11 en contact avec la portion immergée de la portion externe de l'extrudat, refroidissement qui est d'autant meilleur que la vitesse d'écoulement du liquide du fond du bac vers les bords de celui-ci est grande.



   REVENDICATION I
 Procédé pour refroidir un extrudat tubulaire, caractérisé en ce qu'on fait passer cet extrudat dans un bain de liquide réfrigérant en le laissant flotter librement sur ce bain, en ce qu'on fixe le niveau de ce bain pour maintenir   l'extrudat    flottant en position sensiblement coaxiale à l'axe d'extrusion, et en ce qu'on forme un écoulement de ce liquide sur la partie flottant de la face externe de l'extrudat par déversement du liquide sur la portion la plus élevée de cette face.



   SOUS-REVENDICATION
 1. Procédé selon la revendication I, caractérisé en ce que le débit du liquide déversé sur l'extrudat est choisi tel que ledit écoulement forme un film liquide.



   REVENDICATION Il
 Installation pour la mise en oeuvre du procédé selon la revendication I, caractérisée en ce qu'elle comprend une source de liquide réfrigérant, un bac destiné à contenir ledit bain et présentant une profondeur suffisante pour permettre la flottaison de   l'extrudat,    au moins un déversoir agencé et disposé de manière à permettre le déversement de liquide sur la portion la plus élevée de l'extrudat flottant sur le bain du bac et des moyens pour assurer l'alimentation du bac et du déversoir en liquide réfrigérant provenant de ladite source. 

**ATTENTION** fin du champ DESC peut contenir debut de CLMS **.



   



  
 



   The present invention relates, on the one hand, to a process for cooling a tubular extrudate and, on the other hand, to an installation for carrying out this process.



   The process is characterized in that this extrudate is passed through a bath of refrigerant liquid, allowing it to float freely on this bath, in that the level of this bath is fixed in order to keep the extrudate floating in a position substantially coaxial with the extrusion axis, and in that a flow of this liquid is formed on the floating part of the external face of the extrudate by pouring the liquid onto the uppermost portion of this face.



   The installation is characterized in that it comprises a source of coolant liquid, a tank intended to contain said bath and having a sufficient depth to allow the floatation of the extrudate, at least one weir arranged and arranged so as to allow the pouring liquid onto the uppermost portion of the extrudate floating on the bath of the tank and means for supplying the tank and the weir with coolant liquid coming from said source.



   The appended drawing represents, by way of example and very schematically, an embodiment of an installation for implementing the method according to the invention:
 fig. 1 is a simplified longitudinal section thereof;
 fig. 2 is a section, on a larger scale, according to II-II of FIG. 1.



   The installation shown is intended to ensure the cooling of a tubular extrudate 1 produced continuously by a die 2 of an extruder 3 of which only the downstream end of the cylinder is visible in the drawing, this extrudate being subjected to traction in the direction F by means of a device not shown tfig. 1).



   This installation comprises a casing 4, which is open at its upper part and the bottom of which has an opening 5 along the edges of which is fixed a pipe 6. The opposite walls 4A and 4B of this casing each have a circular window 7A and 7B. These two windows are arranged coaxially with the extrusion axis of the die 2 and their diameter is slightly greater than that of the extrudate 1 produced by this die.



   An annular seal 8A, respectively 8B, is fixed to the wall 4A, respectively 4B, all around the window 7A, respectively 7B. This seal, which is made of flexible material, for example plastic, is intended to close the space between the edge of the window 7A, respectively 7B, and the outer wall of the extrudate passing through the window 7A, respectively 7B, when subjected to the traction in direction F, mentioned above.



   Inside the casing 4, the installation comprises in particular a container 9 (fig. 1 and 2) which is constituted by a sector of a cylindrical skirt fixed to the wall 4A of the casing 4 (fig. 1), this wall thus also constituting the left wall of the tank, and along the right edge of which is fixed a plate 9A having the shape of a ring sector, the internal diameter of which is slightly greater than the external diameter of the extrudate 1, this plate 9A constituting the right wall of the tank. A semi-annular seal 10, fixed to the external face of the plate 9A, closes the passage between the rounded part of the upper edge of this plate and the extrudate.



   This tank 9 is in fact intended to contain a bath 11 of refrigerant liquid which is permanently introduced into the tank by means of a pipe 12 opening into the bottom of the tank and attached to a general supply duct 13 terminating at a source. coolant not shown. This liquid can for example be water.



   As the supply of the tank 9 with liquid is continuous, and that, on the other hand, this tank is not provided with any outlet orifice, the liquid of the bath 11 circulates continuously between the bottom of the tank and its edges and overflows from this tank to fall back into enclosure 4.



   As we will see, the capacity of liquid overflowing from the tank 9 is, at each instant, greater than the quantity of liquid brought to this tank via the pipe 12.



   In fact, in addition to the tank 9, the installation shown also comprises a second tank 14 subdivided into two tanks 14A and 14B with each of which is associated a weir 15A, respectively 15B, and which are supplied with refrigeration liquid, from the conduits 13, via connection pipes 16A and 16B. The tray 14 has a length substantially identical to that of the tray 9 and is disposed above the latter, symmetrically on either side of its median plane, at a level sufficient to allow an extrudate of the size of the latter. illustrated in the drawing to float freely on the bath 11 without coming into contact with the tank 14.



   Thanks to the installation described, it is possible to cool any tubular section produced by an extruder, as the extrusion proceeds, without having to guide and hold this section by mechanical means resting on the external face of the section, which therefore eliminates the possible risk of unwanted deformations of the profile.



   In fact, with this installation, the extruded product is maintained at the same level, corresponding substantially to that at which the extrusion took place, throughout the cooling operation, and this because this operation is carried out while the extrudate floats freely on the bath 11 of the tank 9, which tank is obviously arranged at the desired height, taking into account the own weight of the extrudate, the specific weight of the cooling liquid used, and the height of liquid displaced by this extrudate in a floating state.



   The cooling is naturally also carried out by the liquid of the bath 11 in contact with the submerged portion of the external portion of the extrudate, cooling which is all the better than the speed of flow of the liquid from the bottom of the tank to the edges of the tank. this one is great.



   CLAIM I
 Process for cooling a tubular extrudate, characterized in that this extrudate is passed through a bath of refrigerant liquid, allowing it to float freely on this bath, in that the level of this bath is fixed in order to keep the extrudate floating by position substantially coaxial with the extrusion axis, and in that a flow of this liquid is formed on the floating part of the external face of the extrudate by pouring the liquid onto the uppermost portion of this face.



   SUB-CLAIM
 1. Method according to claim I, characterized in that the flow rate of the liquid poured onto the extrudate is chosen such that said flow forms a liquid film.



   CLAIM It
 Installation for carrying out the method according to Claim I, characterized in that it comprises a source of coolant, a tank intended to contain said bath and having a sufficient depth to allow the extrudate to float, at least one weir arranged and disposed so as to allow the discharge of liquid on the highest portion of the extrudate floating on the bath of the tray and means for supplying the tray and the weir with refrigerant liquid coming from said source.

** ATTENTION ** end of DESC field can contain start of CLMS **.

Claims

** ATTENTION ** start of field CLMS can contain end of DESC **.

The present invention relates, on the one hand, to a process for cooling a tubular extrudate and, on the other hand, to an installation for carrying out this process.

The process is characterized in that this extrudate is passed through a bath of refrigerant liquid, allowing it to float freely on this bath, in that the level of this bath is fixed in order to keep the extrudate floating in a position substantially coaxial with the extrusion axis, and in that a flow of this liquid is formed on the floating part of the external face of the extrudate by pouring the liquid onto the uppermost portion of this face.

The installation is characterized in that it comprises a source of coolant liquid, a tank intended to contain said bath and having a sufficient depth to allow the flotation of the extrudate, at least one weir arranged and arranged so as to allow the pouring liquid onto the uppermost portion of the extrudate floating on the bath of the tank and means for supplying the tank and the weir with coolant liquid coming from said source.

The appended drawing represents, by way of example and very schematically, an embodiment of an installation for implementing the method according to the invention: fig. 1 is a simplified longitudinal section thereof; fig. 2 is a section, on a larger scale, according to II-II of FIG. 1.

The installation shown is intended to ensure the cooling of a tubular extrudate 1 produced continuously by a die 2 of an extruder 3 of which only the downstream end of the cylinder is visible in the drawing, this extrudate being subjected to traction in the direction F by means of a device not shown tfig. 1).

This installation comprises a casing 4, which is open at its upper part and the bottom of which has an opening 5 along the edges of which is fixed a pipe 6. The opposite walls 4A and 4B of this casing each have a circular window 7A and 7B. These two windows are arranged coaxially with the extrusion axis of the die 2 and their diameter is slightly greater than that of the extrudate 1 produced by this die.

An annular seal 8A, respectively 8B, is fixed to the wall 4A, respectively 4B, all around the window 7A, respectively 7B. This seal, which is made of flexible material, for example plastic, is intended to close the space between the edge of the window 7A, respectively 7B, and the outer wall of the extrudate passing through the window 7A, respectively 7B, when subjected to the traction in direction F, mentioned above.

Inside the casing 4, the installation comprises in particular a container 9 (fig. 1 and 2) which is constituted by a sector of a cylindrical skirt fixed to the wall 4A of the casing 4 (fig. 1), this wall thus also constituting the left wall of the tank, and along the right edge of which is fixed a plate 9A having the shape of a ring sector, the internal diameter of which is slightly greater than the external diameter of the extrudate 1, this plate 9A constituting the right wall of the tank. A semi-annular seal 10, fixed to the external face of the plate 9A, closes the passage between the rounded part of the upper edge of this plate and the extrudate.

This tank 9 is in fact intended to contain a bath 11 of refrigerant liquid which is permanently introduced into the tank by means of a pipe 12 opening into the bottom of the tank and attached to a general supply duct 13 terminating at a source. coolant not shown. This liquid can for example be water.

As the supply of the tank 9 with liquid is continuous, and that, on the other hand, this tank is not provided with any outlet orifice, the liquid of the bath 11 circulates continuously between the bottom of the tank and its edges and overflows from this tank to fall back into enclosure 4.

As we will see, the capacity of liquid overflowing from the tank 9 is, at each instant, greater than the quantity of liquid brought to this tank via the pipe 12.

In fact, in addition to the tank 9, the installation shown also comprises a second tank 14 subdivided into two tanks 14A and 14B to each of which is associated a weir 15A, respectively 15B, and which are supplied with refrigeration liquid, from the conduits 13, via connection pipes 16A and 16B. The tray 14 has a length substantially identical to that of the tray 9 and is disposed above the latter, symmetrically on either side of its median plane, at a level sufficient to allow an extrudate of the size of the latter. illustrated in the drawing to float freely on the bath 11 without coming into contact with the tank 14.

Thanks to the installation described, it is possible to cool any tubular section produced by an extruder, as the extrusion proceeds, without having to guide and hold this section by mechanical means resting on the external face of the section, which therefore eliminates the possible risk of unwanted deformations of the profile.

In fact, with this installation, the extruded product is maintained at the same level, corresponding substantially to that at which the extrusion took place, throughout the cooling operation, and this because this operation is carried out while the extrudate floats freely on the bath 11 of the tank 9, which tank is obviously arranged at the desired height, taking into account the own weight of the extrudate, the specific weight of the cooling liquid used, and the height of liquid displaced by this extrudate in a floating state.

The cooling is naturally also carried out by the liquid of the bath 11 in contact with the submerged portion of the external portion of the extrudate, cooling which is all the better than the speed of flow of the liquid from the bottom of the tank to the edges of the tank. this one is great.

CLAIM I Process for cooling a tubular extrudate, characterized in that this extrudate is passed through a bath of refrigerant liquid, allowing it to float freely on this bath, in that the level of this bath is fixed in order to keep the extrudate floating by position substantially coaxial with the extrusion axis, and in that a flow of this liquid is formed on the floating part of the external face of the extrudate by pouring the liquid onto the uppermost portion of this face.

SUB-CLAIM 1. Method according to claim I, characterized in that the flow rate of the liquid poured onto the extrudate is chosen such that said flow forms a liquid film.

CLAIM It Installation for carrying out the method according to Claim I, characterized in that it comprises a source of coolant, a tank intended to contain said bath and having a sufficient depth to allow the extrudate to float, at least one weir arranged and disposed so as to allow the discharge of liquid on the highest portion of the extrudate floating on the bath of the tray and means for supplying the tray and the weir with refrigerant liquid coming from said source.

SUB-CLAIMS 2. Installation according to claim II, characterized in that the tank has a cross section having a profile which is homothetic with respect to that of the cross section of the portion of the extrudate intended to be immersed in the bath of coolant.

3. Installation according to sub-claim 2, intended for cooling a tubular extrudate of cylindrical shape, characterized in that the tray is constituted by a sector of a cylindrical casing whose axis of symmetry corresponds substantially to the longitudinal axis of the extrudate when the latter floats on the bath and the radius of curvature of which has a length greater than that of the radius of curvature of the outer face of this extrudate and by the fact that said means are arranged so that the The entry into the coolant tank takes place in the lowest portion thereof.