FR2494626A1 - PROCESS AND APPARATUS FOR MANUFACTURING SYNTHETIC RESIN TURBULENCE ELEMENTS - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS AND AN APPARATUS FOR MANUFACTURING TURBULENCE ELEMENTS IN SYNTHETIC RESIN. THE APPARATUS INCLUDES AN EXTRUSION MACHINE 20 OF WHICH THE DIE HEAD 26 CARRIES A NOZZLE 34 FROM WHICH A MELT RESIN IS EXTRUDED. THE RESIN IS ROTATED AROUND ITS LONGITUDINAL AXIS AT THE SAME TIME AS IT IS EXTRUDED, AND IT IS IMMEDIATELY IMMEDIATELY IN WATER CONTAINED IN A COOLING CONTAINER 42. FIELD OF APPLICATION: MANUFACTURING OF TURBULENCE ELEMENTS FOR HEAT EXCHANGERS, ESPECIALLY RADIATORS.

Description

The invention relates to a method and an apparatus

  of manufacturing a turbulence element made of syn-

  theatrically, in the form of parts, in fluid flow paths inside a heat exchanger such as a radiator, etc., these

  which may increase the effect of thermal radiation

  that or heat absorption of the heat exchanger.

  To date, turbulence elements made from a thin metal ribbon have been proposed, molded so as to be each composed of two wave-shaped bands of different phases, by press work, etc. These turbulence elements are introduced as parts in fluid flow circuits, inside a heat exchanger such as a radiator, etc., in order to cause agitation of the fluid and improve the radiation effect or

thermal absorption.

  However, these metallic elements of turbulence have the following drawbacks: when they are wound on a coil, the edges of their strips of

  wavy form are crushed, causing an entanglement-

  bands; since the turbulence metal parts of a given dimension, in which the turbulence metal elements are cut, are kept curved in the form of an arc, their curved sections must be manually shaped, one by one, during the introduction of the turbulence pieces in the fluid flow paths inside a heat exchanger, which is very painful work,

  long and laborious; and, since the pieces of tur-

  bulence are made of metal, the weight of the exchanger

of heat is important.

  The subject of the invention is a method for manufacturing plastic turbulence elements, a

  excellent precision, and at a high working speed.

  The invention also relates to an apparatus for manufacturing plastic turbulence elements, with excellent precision and at a high working speed. In order to achieve the above-mentioned objectives, the invention relates to a method for producing turbulence elements made of synthetic resin, consisting in extruding the heat-melt resin in extrusion means from a slot in a nozzle. rotating

  these means, while the molten resin is rotated

  around its central axis, which automatically

  twist the molten resin, and pass the extruded resin under water for

  cool and solidify. The invention also relates to

  a synthetic resin turbulence element manufacturing apparatus comprising an extrusion machine for melting the resin by heat and extruding the molten resin, a rotating nozzle being rotatably mounted on the machine; extrusion and having, at its front end, a slot which allows the molten resin to be rotated about its central axis and to be extruded outwardly of the nozzle, the machine also having a container filled with water in which the extruded resin is cooled and

  solidified, and a device for pulling the cooled resin

die and solidified.

  The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting examples and in which: FIG. 1 is a perspective view of a conventional turbulence element;

  FIG. 2 is a longitudinal section of

  trant parts of the turbulence element of Figure 1 used in a radiator;

  FIG. 3 is a longitudinal section

  partial form of an embodiment of the apparatus

  manufacture of turbulence elements made of plastic material according to the invention;

  FIG. 4 is a longitudinal section through

  showing the nozzle used in the device

  shown in Figure 3; Figure 5 is a diagrammatic elevation of a device for cutting the plastic turbulence elements manufactured by the apparatus shown in Figure 3 to form parts of a given size; FIGS. 6A and 6B are respectively a front view of a nozzle whose slot is of a certain shape, and a schematic perspective view of a turbulence element obtained using this slot: FIGS. 7A and 7B are respectively a front view of a nozzle having a slot of another shape and a schematic perspective view of a turbulence element obtained using this slot; FIGS. 8A and 8B are respectively a front view of a nozzle having a slot of another shape and a schematic perspective view of a turbulence element obtained using this slot; and FIG. 9 is a diagrammatic elevation, partly in section, of another embodiment of the turbulence element manufacturing apparatus.

  plastic material according to the invention.

  FIG. 1 shows a typical turbulence element made from a thin metal ribbon and molded to consist of two ribbons having the waveform in different phases, by press work, etc. to 30 pieces of turbulence are introduced,

  as shown in FIG. 2, in listening paths 14

  There is no need for hot water inside a radiator 12 to stir the hot water and thereby increase the efficiency with which the heat is conducted to the fins.

  16 and, therefore, the effect of thermal radiation.

  However, these metal elements 10 of

  bulence have several disadvantages: when wound on a reel, the edges of their ribbons

  wavy shapes are crushed, which causes an

  wrapping ribbons; since the parts of a given dimension, in which the turbulence elements are cut, have bent sections along arcs, the bent sections must be manually shaped, one by one, during the introduction of the pieces of turbulence in the flow paths 14 of the fluid, which requires very difficult work, long and laborious; and, since the pieces of turbulence

  are made of metal, the weight of the radiator 12 is high.

  In these circumstances, it appeared very desirable

  to have a method and apparatus for manufacturing

  cation of turbulence elements, to eliminate

  the disadvantages indicated above.

  The invention responds to the request indicated above.

  An embodiment of the invention will be

  described in more detail with reference to FIGS. 3 to 8B.

  The process according to the invention will be described at the same time as the apparatus according to the invention, since it is possible to

  consider that this process is implemented by the apparatus.

  Reference numeral 20 designates a machine

  extrusion machine or extruder in which a synthetic resin

  tick is heat fused and extruded at the output of said machine. The latter comprises a hopper 22,

  a screw 24 and a die head 26.

  The die head 26 has, on its underside,

  a conduit 30 for guiding the molten resin in order to make it easier. re out of the extrusion machine 20, perpendicular to the latter. The head 26 also has a bulging cylindrical portion 32 which makes

protrude down.

  A rotatable nozzle 34, in the form of a cap, is applied to the lower end of the bulged portion 32 at the outer peripheral surface of which it

  is connected so that it can rotate.

  The central front end of the nozzle 34 has a slot 36 which communicates with the duct 30 formed in the bulging portion 32. The slot may have the shape of a straight opening or several openings radially from the center of the nozzle, as shown on

Figures 6A, 7A and 8A.

  The rotary nozzle 34 is rotated at variable speeds by means of a chain connected to

  a control mechanism (not shown) at variable speed

  and pass on teeth 38 formed on the circumference

  the nozzle. As a speed control mechanism

  variable, a gear mechanism suitable for

nable, a strap, etc.

  A container 42 filled with water is disposed

  below the front end of the rotary nozzle 34 and has a depth of about 1 meter. This container is filled with water for cooling the resin

  extruded and coming out of the slot 36.

  The distance between the surface of the water contained in the container 42 and the underside of the nozzle 34 can be adjusted by equipping the container 42 with a water tap and a water tap. 'water,

  placing the container 42 on a suitable support base

  nable, adjustable in height, etc. A roller 44 is disposed inside and at the bottom of the container 42, opposite the front end of the nozzle 34, and a guide roller 46 is arranged

  inside and at the top of the container 42.

  A pulling device 48 comprises two groups of opposed drive rollers 50a and 50b for removing the resin from the water container, at a speed equal to that at which the resin is extruded from the machine, and guiding this resin between said rollers. 52 denotes a receiver coil of

resin.

  The first embodiment of the apparatus

  according to the invention is constructed as described above.

  Now, the operation of this first embodiment will be described in application of the corresponding method. The resin particles are introduced into the hopper 22 and melted by heat in the extrusion machine or extruder 20. The molten resin is advanced towards the conduit 30 of the bulging portion 32 by means of the

  screw 24, then extruded downwards, perpendicularly

  the downward direction is slightly inclined, the molten resin may bend downwards, under the effect of its own weight, towards the vertical. Therefore, the downward direction is preferably vertical. The resin is then guided inwardly of the water container 42, conducted to the lower surface of the roller 44, then to the upper surface of the guide roller 46, the direction of movement being reversed, pinched between the drive rollers 50a and b of the traction device 48, and wound on the

receiver coil 52.

  In the process described above, the resin is guided inwardly of the water container 42 as it is rotated about its vertical axis by the action of the rotating nozzle 34. The resin encounters

  a certain resistance opposed both by the water containing

  in the container and by the portion of the resin which has been cooled and solidified and which is kept in contact with the lower surface of the roller 44 so as not to rotate. Between the front end of the nozzle 34 and the surface of the water, the resin is automatically subjected to twisting, then it is cooled and solidified in the water container, then pulled continuously by the traction device 48. Turbulence Parts 60

  given length, obtained in advance from the tur-

  Bulb driven by the traction device 48 to a supply device 54 capable of continuously advancing the turbulent element over a given length and by cutting, with the aid of a device 56, of the turbulent element, can to be stored, as shown on

  Figure 5, or introduced directly into the

  fluid flow jets of the heat exchanger by means of a dispensing mechanism (not shown)

  having a suitable guide channel.

  The pitch of the turns formed by the adjacent helical fins of the turbulent element can be determined independently or as a function of the extrusion speed of the resin, the speed of rotation of the nozzle 34 and the distance between the end before the nozzle and the surface of the water contained in the container 42. When it is desired, for example, to divide by two the pitch of the turbulence element, it is possible to double

  the rotational speed of the nozzle 34.

  Helical elements of turbulence, having the configurations shown in Figs. 6 (B), 7 (B) and 8 (B), can be obtained by giving the slot the shapes shown respectively in Figs. 6 (A), 7 ( AT)

and 8 (A).

  As described above, the first embodiment of the invention makes it possible to easily manufacture turbulence elements having a precise and uniform outside diameter and fins of precise uniform thickness and pitch, and it has the following advantages: As the speed of work can be accelerated, productivity is improved and the cost of production is reduced; since the turbulence elements are made of synthetic resin, the heat exchanger is lightened and the turbulence pieces are easily

  maintained in a straight form if the turbulent element is

  cut even after being wound on the take-up spool; and, therefore, since the difficult manual operation of reshaping the bent sections of the turbulence pieces is no longer necessary, the time and work required for placing the turbulence pieces in the flow paths of

  fluid are considerably reduced.

  The second embodiment of the apparatus according to the invention will now be described with regard to the

  figure 9. In the description that follows, the elements identified

  or similar to those of the first form of reali-

  the same numerical references. In Fig. 9, numeral 20 denotes an extrusion machine or extruder for melting by heat and extruding a synthetic resin. This machine comprises a hopper 22, a die head 26 and a hat-shaped rotary nozzle 64 having a structure similar to that of the rotary nozzle of the first embodiment and mounted so as to be freely rotatable.

  on the side of the die head 26.

  Although the shape of the slot made in the front end of the rotary nozzle 64 of this embodiment is not clearly illustrated, this slot may consist of a straight opening or -radial openings, similar to the configurations of the slot of the first embodiment, shown in the figures

6 (A), 7 (A) and 8 (A).

  The heat-melt resin within the extrusion machine of this embodiment is extruded from the slit into the substantially horizontal direct-ion as it is rotated about its central axis. In addition, the direction in which the resin

  is extruded may be slightly inclined.

  A cooling container 82 contains water and is disposed near the front end.

  of the nozzle 64. The container is closed hermetically -

  its upper part and is divided into a first cooling chamber 86 located on the side of the nozzle 64, and a second cooling chamber 88 located on the other side, the two chambers being separated by a partition 84. Holes 90 , 92 and 94 are respectively formed in the side wall located on the side of the nozzle 64, in the side wall on the other side and in the partition 84 of the cooling container, these holes having diameters slightly greater than the diameter of the extruded resin and being all aligned

  with the slot of the nozzle 64, in the horizontal direction.

  Therefore, the resinextruded and exiting the slot enters the first cooling chamber 86

  by the hole 90, then in the second chamber 88 cooling

  drainage through the hole 94, and then leaves the container

  82 cooling through the hole 92.

  A suction pipe 100 is connected at one end to a suitable suction pump (not shown) and its other end passes through the wall of the second cooling chamber 88 to be placed at a higher level than the holes 90, 92. and 94 and to open into the space between the sealed upper surface of the second cooling chamber and the surface of the water contained in the second chamber 88. A water supply pipe 102 is connected to the

  upper surface of the first cooling chamber 86

is lying.

  The resin emerging from the hole 92 of the second chamber

  88 is placed under pressure between two groups of rollers 50a and 50b and is driven

  by a traction device 48, at a synchronous speed

  based on the extrusion speed of the resin by the machine

  extrusion, and is wound on a reel

ceptrice 52.

  The second embodiment of the apparatus

  according to the invention is constructed as described above.

  Now, the operation of this second embodiment will be described in the implementation

the corresponding process.

  The heat-melt resin inside the extrusion machine is extruded from the slot of the

  rotary nozzle 64, in a substantially horizontal direction

  at the same time as it is rotated about its central axis by rotation of the nozzle 64. It is then cooled and solidified inside the cooling container 82, passing successively through the holes 94 and 92, and it is driven by the device 48

  pulling and wound on the spool 52.

  The resin is automatically helically twisted by its own rotation around its central axis, between the front end of the nozzle 64 and the inside of the first cooling chamber 86, at the same time as it is supported by the a portion of resin having been cooled inside the cooling vessel 82 1 0, and the rotation of the resin ceases

  in the traction device 48. We can determine free-

  the helical shape by suitably selecting the slot configuration, as well as in the first embodiment (Figs. 6 (A) through 8 (B)). Since the air in the container

  82 is discharged through the suction pipe 100

  space, the space between the upper inner surface

  container and the surface of the water contained in the container is constantly

  depression and the surface of the water contained in the

  The cooling pipe is located at the upper end of the suction pipe 100, this end being above the level of the holes 90 and 92, so that the resin passing through the holes 90, 94 and 92 is

  immersed in water and cools sufficiently.

  In this case, the depression under which the above-mentioned space is maintained is adjusted so that its absolute value is greater than the water pressure.

  at the locations of holes 90 and 92 and, consequently,

  water flows only slightly from the

  cooling through holes 90 and 92.

  Since part of the feed water

  cooling container 82, arriving by

  the supply pipe 102 and rising above the end

  upper half of the suction pipe 100, and that air entering the cooling vessel 82 through the holes 90 and 92 are discharged through the suction pipe,

  the above-mentioned space is constantly maintained under a

  whose absolute value is greater than the pressure

aforementioned water.

  Since the side wall of the first cooling chamber 86, located on the side of the nozzle 64, can be made thin in that the pressure exerted by the water towards the outside of the cooling container is lowered. by the aforesaid depression, the space between the front end of the nozzle 64 and the water contained in the first cooling chamber can be sufficiently reduced to prevent any deformation of the resin that may occur in this space as a result of a flight from the

molten resin.

  In addition, when the side wall of the first cooling chamber is brought closer to the front end of the nozzle 64, as previously described, given

  that the water contained in the first cooling chamber

  only flows slightly from the chamber through the hole 90, towards the nozzle 64, the extrusion of the resin is not

not embarrassed.

  The pitch of spirals or helical fins adjacent to

  of the turbulence element can be determined from the extrusion rate of the resin, the rotational speed of the nozzle 64, the distance between the front end of the nozzle 64 and the cooling vessel 82, etc. We can vary the amplitude of the depression

  using the pulsation of a suction pump (not shown

  and there is a risk of oscillatory

  of the water contained in the cooling vessel 82

  is lying. However, in the embodiment described, this oscillation is effectively prevented by the presence of the partition 84 and, consequently, the deformation of the resin inside the cooling container.

can be avoided.

  However, the partition can be removed, for example when using a low pulsation suction pump. Since the resin is extruded in a substantially horizontal direction, it is cooled, solidified and pulled in the horizontal direction, as

  previously described, the same function can be

  and the same effects as in the first embodiment. In addition, since the second embodiment eliminates the risk of disadvantages that may result from the change of direction of advance of the resin in the cooling container, as is the case in the first embodiment, it is possible to efficiently produce turbulence elements of a

excellent precision.

  The present invention is not limited to the first and second embodiments described and various modifications can be made to these embodiments without departing from the scope of the invention. For example, the resin can be extruded from the nozzle at a relative speed different from the rotational speed of the nozzle.

  the nozzle, while being turned around its central axis.

  As described above, according to the invention, it is possible to produce turbulence elements having excellent accuracy, at a high working speed, by extrusion of the heat-melt synthetic resin, the resin being extruded from the slot of the rotating nozzle as it rotates around its own axis, which automatically gives the resin

  fuses a helical twist. The molten resin is

  dragged into the water where it is cooled

  die and solidified. Therefore, the present invention has the advantage of high productivity and low production cost. In addition, since the weight of the plastic turbulence pieces is small, the weighting of the heat exchanger, for example a radiator, can be effectively avoided and, since the turbulence pieces are easily maintained in straight shape, even when the resin is cut after being wound on a reel, the difficult manual operation of reshaping. the curved sections of the turbulence pieces, which had to be performed until now during the introduction of said turbulence pieces in the fluid flow paths

  inside the heat exchanger, can be eliminated.

  The present invention therefore also provides a significant reduction in time and work compared to the prior art.

Claims (5)

  1. Method of manufacturing turbulence elements   synthetic resin, characterized in that it consists in extruding, with the aid of a slot (36) formed in a rotary nozzle (34 or 64), a device (20) for extruding   a synthetic resin heat-melted inside the   of the extrusion device, the molten resin being rotated around its central axis at the same time as it is extruded, so as to automatically undergo a helical twist, and then to pass the extruded resin   in water to cool and solidify.   2. Method according to claim 1, characterized in that the molten resin is extruded vertically   downwards from the slot formed in the rotating nozzle   of the extrusion device, at the same time as   is turned around its central axis.   3. Method according to claim 1, characterized in that the molten resin is extruded horizontally   from the slot formed in the rotating nozzle of the   Extrusion system, at the same time as it is turned around of its central axis.   4. Turbine element manufacturing apparatus   lence of synthetic resin, characterized in that it comprises an extrusion machine (20) which has an extrusion outlet and which is intended to melt the resin with heat and to extrude the resin melted by said outlet of extrusion, a rotatable nozzle (34 or 64) rotatably mounted on the extrusion outlet of the machine and having, at its forward end, a slot (36) for the molten resin to be   rotation about its central axis and extruded vertically   downwards, from the slot, a container   (42 or 82), filled with water, and arranged below the   moth before the rotary nozzle to cool and solidify the resin that has been extruded from said nozzle slot, and a pulling device (48) for driving the resin which has been cooled and solidified into the water container.   5. Apparatus for manufacturing turbulence elements made of synthetic resin, characterized in that it comprises an extrusion machine (20) which has an extrusion outlet and which is intended to melt the resin with heat and in extruding the molten resin through said outlet, a rotatable nozzle (64) rotatably mounted on the extrusion outlet of the machine and having, at its forward end, a slot (36) which allows the molten resin being rotated about its central axis and extruded approximately horizontally from said slot, a container (82) connected to a water supply device, filled with water and having side walls which have holes (90 92) of a diameter slightly greater than the outer diameter of the resin extruded from the slot of the nozzle, these holes being aligned with one another so as to allow the extruded resin to pass roughly horizontally in the holes, the upper part of the container being sealed so that the extruded resin is cooled and solidified in said container, a suction pipe (100) communicating at one end with a suction pump and its other end opening into the container; at a level higher than that of the holes, and a pulling device (48) for drawing the resin which has been cooled   and solidified in the water container.