FR2490312A1 - PIPE MADE OF A FLEXIBLE OR RIGID PLASTIC MATERIAL FOR THE TRANSPORT OF A COOPERATING AGENT - Google Patents

Abstract

THE INVENTION RELATES TO A HOSE OF PLASTIC MATERIAL FOR THE TRANSPORT OF A HEAT TRANSFER FLUID. THE INTEREST OF THE PIPE 12 RESIDES IN THE FACT THAT IT PRESENTS, ON ITS PERIPHERY 16, RIBS 18 AND RIBS 20 WHICH ARE SUCCESSFUL, WHICH EXTEND IN THE LONGITUDINAL SENSE AND WHICH ALTERNATE IN THE CIRCONFERENTIAL SENSE. THESE RIBBLES 18 AND RIBS 20 INCREASE THE SURFACE OF PIPE 12 AND THUS IMPROVES THE SUPPLY OF HEAT BY HOT WATER FLOWING INTO PIPE 12. SUCH A PIPE IS USED, FOR EXAMPLE, IN GROUND HEATING.

Description

The present invention relates to a pipe made of a plastics material

  flexible or rigid for transporting a heat transfer agent. This heat transfer agent is, in this case a liquid heating or cooling agent, in general, water. Heaters in the ground, also called heaters by large surfaces include a pipe for transporting the heat transfer agent placed and maintained in the ground. In this case, the pipes are laid in the ground according to a determined pattern comprising strands parallel to each other and elbows, etc., and are connected to the supply and return of a central heating installation. The pipe must then meet mechanical requirements

  and thermal. The mechanical requirements aim, in general,

  neral, sufficient strength of the pipe. The strength increases with the thickness of the wall. The requirements

  thermal devices, on the other hand, aim at a thermal conductibility

  high level. Now, the thermal conductivity of the pipe

  decreases as the thickness of its wall increases.

  However, a high thermal conductivity is

  sought, because it reduces the losses incurred during the transmission of heat and allows a lowering

  supply temperatures. During the construction

  tion of the heating pipes, efforts are therefore

  to find a compromise between these requirements

  whose effects are contradictory.

  Currently, mainly circular pipes are used. Their manufacture does not

  causes no difficulty and their pose is also

  very simple. Diameters and thicknesses of

  wall can be modified. Both requirements

  above, however, can not be replaced by

  folds ideally because a circle is the

  which for the largest surface, presents

  the smallest periphery. The surface of the pipe and thus its thermal conductivity or the amount of heat transmitted to the surrounding ground are thus limited. If, for any reason, the diameter of the pipe is increased, the height of the soil must be increased simultaneously. This is necessary

  for the soil to maintain its static carrying capacity

  than. For thicker soil, however, it is also necessary to heat a larger soil mass. This means

  a loss of heat because we are not looking for a. chauf-

  the floor, but the air space

above it.

  For a larger diameter of the pipe, it is also necessary to increase the thickness of its wall, otherwise its

  static strength would be adversely affected.

  With increased wall thickness, efforts are also made to counteract the ovalization of the dreaded pipe in the laying elbows. The plastic has only one

  relatively low thermal conductivity. An increase

  the thickness of the wall decreases, by

  sequent, even more the thermal conductivity.

  Attempts to lower the temperature of the food

  thus have almost no success.

  Oval section pipes are also known. For the same section, an oval pipe

  has a larger area than a round pipe.

  An oval pipe requires, however, a higher ground height and / or increased wall thickness to provide the necessary strength. This virtually cancels the increase in thermal conductivity resulting from the larger area. An additional disadvantage

  lies in the fact that laying an oval pipe is dif-

  ficult. The section of the elbows formed during the pose may further be strangled. Moreover, it is difficult to connect the accessories and ensure their

seal.

  In conclusion, the increase in 'diameter and wall thickness as well as the use of

  oval section brings only advantages which

  also drawbacks. Material and labor costs are, however, high and are not

  not compensated for thermal benefits.

  From this state of the art, the object of the invention is to provide a hose for

  transport of a heat transfer agent which has a

  larger face without its static strength is affected or that others of the aforementioned drawbacks appear. For this purpose, according to the invention,

  the pipe has radial depressions which

  tooth longitudinally in its periphery. These hollows increase the surface area from 20 to 30. The heat dissipation increases with the surface of the pipe. The energy losses are reduced, and

  than the supply temperatures.

  Another advantageous factor is that the thick

  wall thickness or wall thickness of the

  pipe in its thinnest places can be reduced

  to a value less than the thickness of pa-

  King of a round section pipe. The strength of the pipe at its locations between the radial recesses is sufficient to maintain the overall strength of the pipe at a high value, even for a relatively low base wall thickness. We observe a so-called bridging effect. Compression tests carried out on section pipes in accordance with the invention did not provide values that were distinctly different from those

  obtained with section pipes. round.

  Advantages also appear during the manufacture of the pipe according to the invention. During its extrusion, better thermal conditions are obtained in the calibration plants as a result

  of its increased surface. This results in a better pre-

  dimensional decision. Tolerances can be

  weaker. This therefore saves money

  SPECT. When laying also, the pipe according to the invention is handled better than the known pipes of round section. In the elbows formed during the installation, the restrictions of the section are practically null. This determines a relative heat gain. Advantageous properties are obtained, in

  particular when laying the pipe in accordance with the

  vention in a screed. Due to the increased surface area of the pipe, the joint and adhesion between the pipe and the screed are improved. Thanks to the depressions or profiling according to the invention, a positive connection is also obtained between the pipe and the yoke. The

  The clevis penetrates the hollows according to the

  An anchorage occurs between the clevis and the pipe. As a result of the different coefficients of thermal expansion of the plastic and the screed, this is particularly interesting. For the round section pipe laid according to the known technique,

  small movements between the clevis and the pipe

  resulting from different thermal expansion coefficients

  rents, occur during improper manufacture of the screed. These relative movements between the screed and

  constantly reproducing pipe can lead to

  shooting at a hose wear. The positive connection between the pipe and the clevis which the invention allows excludes such

relative movements.

  In order to fix them in their intended position in the ground, the pipes are placed in stirrups or clips known as "clips". These

  calipers are made of a moderately elastic material

  than. They have notches in which the

  pipes are slipped. For fixing the pipes

  Naked round section, stirrups have, in addition, protrusions and stops. The pipes are pressed against these stops. Due to the elasticity of the stirrup material and that of the pipe, a certain elastic interlocking effect occurs during the installation in the stirrup. The pipes are thus firmly

  maintained. The depressions provided for in accordance

  now constitute their own

  in which hangs a stirrup provided with projections.

  The stirrups can thus be manufactured without stops for fixing the pipes according to the invention. The laying or fixing of pipes according to the invention

  in this way is simplified and made less expensive.

  is. Round section pipes tend to

  keep, even after reeling, the shape of a

  the water that has been conferred on them when squeezing on a reel or on a drum. When laying pipes of round section, this causes a twist that makes it difficult to install in the intended position. The pipe sections according to the invention do not have this twist and can be laid in a more

  uniform and significantly more precise.

  In conclusion, the manufacture of a pipe according to the invention requires only once the presence of an expensive extrusion tool and, for the rest, the manufacture, laying and

  in operation, such a pipe offers only

  floors. The recesses according to the invention can

  be made practically in any form.

  It has proved advantageous that the hollows are formed of grooves arranged at equal distances from the

  each other in the circumferential direction. The cane

  lures may be of circular or oval section or

  any other usable geometric section.

  The grooves must, in any case, have a section such that the material is not cut at an acute angle. This avoids

notch tensions.

  As mentioned above, the depressions, in an advantageous embodiment, are separated from each other by equal distances, oensidere in the

  circumferential direction of the pipe. In this form of

  cution, it is advisable to provide, between the flutes, ribs convex outward complementary of the flutes. In this form

  of execution, -the periphery- of the pipe can be

  to appear as a wavy line formed of corrugations and intermediate valleys which follow one another in a uniform manner. It is advisable, when forming these corrugations separated by recesses, to ensure that accessories of the pipe according to the invention,

  for example, cable ties to be placed on

  riphérie, can be adapted to the profile of this pipe.

  The function of the clamp is thus ensured and the sealing of the accessory X the circular periphery

internal hose is guaranteed.

  One embodiment of the invention will be

  hereinafter, by way of example, with reference to the appended drawing, in which:

  FIG. 1 is a view of a pipe end con-

form to the invention;

  FIG. 2 is a sectional view along the line

II-II of FIG. 1.

  The drawings illustrate a pipe 12 with a round inner wall 14 and a profiled outer wall 16. This outer wall is formed of recesses or grooves 18 and ribs 20 which succeed one another. These flutes and

  these ribs extend over the surface of the parallel pipe

  parallel to its longitudinal axis and connect to each other without a projection along narrow lines 22. In the example shown, the grooves 18 as well as

  the ribs 20 have an arc-shaped section of cer-

  cleo As mentioned above, they can, however,

  also have an oval section or another

geometric section.

  A pipe made according to the invention is determined by its inside diameter a, its small

  outer diameter b and its large outside diameter c.

  As mentioned above, it should be noted that the base wall thickness (b min divided by 2) may remain smaller than the wall thickness of a

  round section pipe without resistance to

pressure suffers.

  A glance at Figs. 1 and 2 and

  simple calculations show that the sum of the surfaces of the grooves 18 and the ribs 20 is greater than

  the surface of a pipe that has an outer circumference

  round ring of outside diameter c. According to the invention

  The rays of the grooves 18 or ribs 20 may vary over a wide range. In general, these rays can be less than 50% of the difference

c - a.

  The pipe according to the invention has been described with reference to a heating in the soil. It could, in the same way, be used in a heating in the walls, in an installation intended to capture the

  ambient heat or also in devices in the-

  which circulating hot water is replaced by a

coolant.

Claims (5)

- CLAIMS -   1 - Pipe made of a flexible or rigid plastic material for the transport of a heat transfer medium (heating or cooling agent), characterized in that it has, in its periphery (16), radial recesses which extend in the longitudinal direction. Pipe according to Claim 1, characterized in that the recesses are grooves (18) arranged at   equidistant from each other in the circumferential direction ential.   3 - Pipe according to claims 1 and 2, characterized   characterized in that the grooves (18) have a cross-section shape of an arc.   4 - Pipe according to claims 1 and 2, characterized   characterized in that the grooves (18) have an oval section.   Pipe according to one of Claims 2 to 4,   characterized in that between the grooves (18) are arranged   outwardly convex ribs (20), which are complementary.