FR2546266A1 - CONDUIT FOR SOLDERABLE AND VERY ABRASIVE MEDIA AND MANUFACTURING METHOD THEREOF - Google Patents

Abstract

THE INTERIOR SURFACE OF A TUBE-ENVELOPE 1 IS LINED WITH A COATING 6 CONSISTS OF AT LEAST ONE LAYER OF CERAMIC PARTICLES 2 FLOODED IN A BED 3 OF PLASTIC MATERIAL OR RUBBER. CHEMICAL INDUSTRY.

Description

Conduit for media capable of flowing and very

  abrasives and its manufacturing process.

  The invention relates to a conduit for

  flowable and highly abrasive

assigned for its manufacture.

  In the usual ways so far, the

  The invention therefore aims to create a duct for this very special use, which has a great ability to withstand mechanical wear and which can therefore be expected to be very long-lived. At the same time, we must create a process by which we can manufacture a pipe of this type,

  in a reliable manner and at acceptable costs

  the invention, the inner surface of an inner tube

  covered with a coating consisting of at least one layer of ceramic particles embedded in a bed of plastic or rubber

  method of manufacturing a conduit of this type con-

  according to the invention, to rotate around

  of its longitudinal axis a tube-envelope and to introduce

  in the tube-shell of the resin of

  plastic or rubber in a state suitable for

  ler, and ceramic particles, to give to the tube-

  the rotational velocity is so great that the ceramic particles are applied under the influence of the c-force, against the inner surface of the casing tube, and continue to rotate the casing tube until hardened or until vulcanization of the plastic resin or rubber. Preferably, the process consists of

  troduce the ceramic particles in the tube-

  envelope and then when the particles of ceramics

  that have been evenly distributed over the

  inner side of it, to intro: duire of the

  plastic resin or rubber.

  There are, of course, already proposals for

  ceramic in pieces in

  If we had chosen, in accordance with this idea, a gluing process to coat the

  inner surface of the ceramic platelet

  that, one could have done it only very difficult, because it would have been necessary to stick the plates one by one on the inner surface of the conduit, which carries

  a very large expense and is absolutely not possible

  It is also possible that even if a single plate is not glued in an absolutely impeccable manner,

  platelets come off from this defective place

  tueux. The invention provides, on the other hand, a problem-free, relatively simple solution that can be

  implemented even for small diameters

  without the danger of the

coating comes off.

  The ceramic particles are spherical or at least substantially spherical, so that they are distributed without obstacles on the inner surface of the jacket-tube The diameter of the balls is between 3 and 10 mm, and the thickness of a layer is of the same order of magnitude, so

  that the ceramic particles do not

  bed only slightly after making a layer,

  it is possible, if necessary, to deposit another layer.

  By hardening the plastic resin or vulcanizing the rubber bed, the ceramic material is permanently fixed by creating, on the inner wall of the jacket tube,

  a ceramic coating layer of cylindrical shape

  drique. Other embodiments emerge from the

description that will follow.

  In the attached drawing, given only for

For example:

  FIG. 1 is a cross-sectional view of a conduit according to the invention, and FIG. 2 is a longitudinal sectional view during the deposition of the coating material of FIG.

  tube-envelope prepared before the incorporation of the coating-

  is lying. The pipe shown in FIG. 1 consists of a shell-tube 1 made of metal, for example steel or plastic, on the inside surface of which

  a single layer of ceramic particles is deposited

  only of spherical shape, so that the thickness of the ceramic layer corresponds to the diameter of the balls of the ceramic particles 2, which diameter

  is preferably between 3 and 10 mm.

  ceramic particles 2 are embedded in a bed 3 in

  rubber or plastic resin, of

  to give a coating 6 adhering to the surface

inside the tube-envelope 1.

  The ceramic particles 2 are made of aluminum oxide, silicon nitride, silicon carbide, zirconium dioxide, or a similar material. To make the bed, it is possible to use rubber or plastic resin. , by

  example of the urethane resin, the epoxy resin,

dique or acrylic resin.

  For the manufacture of this conduit, the casing tube 1 is provided, on both sides, temporarily with a

  ring disk 4 which is fixed in a suitable manner

  and which forms radially inwardly a wall having a sufficient height relative to the thickness of the coating 6 to be produced.

  the tube-envelope around its longitudinal axis.

  It is deposited on the inner surface of the tube-enve-

  1, via a supply duct 5, spherical or at least substantially spherical ceramic particles 2 which, due to the centrifugal force, are evenly distributed over the inner surface of the tube-envelope and form a ceramic layer corresponding to the diameter of the balls As soon as the ceramic particles 2 have been

  uniformly distributed over the

  of the casing tube 1, the

  tube-casing 1, through the supply duct, the resident

  plastic material capable of flowing or rubber

  The quantity introduced is measured in such a way that a bed 3 of resin made of plastic or rubber is formed.

  about the thickness of the layer produced aupara-

  In this case, the ceramic particles are still slightly protruding from the surface of the bed 3. After having introduced the plastic resin or the rubber and the ceramic material, the rotation is continued.

  the casing tube 1 for a fixed period of time

  where the plastic resin is hard

  where the rubber is vulcanized For hardening

  in the case of a heat-curing plastic resin, or, in the case of vulcanization when using rubber, the heating tube 1 is heated for heating in an oven, or has the heating elements on the outside of the tube-envelope 1 In both cases, it is necessary to continue to turn the tube in the heated atmosphere which surrounds it After the hardening of the

  plastic resin, or after the vulcanization

  the rubber, the casing tube 1 is stopped rotating and, after removing the annular disks 4, the manufacturing process is terminated.

  of the duct which is now composed of the tube-enve-

  loppe 1 to which is fixed firmly the coating 6.

  The duct thus produced can be used for a long time for the transport of very abrasive substances, because of the ceramic layer having a high wear resistance, which is on the inner surface of the casing tube 1 As

  the ceramic particles 2 are incorporated solid-

  in the resin bed of plastic material or rubber 3, there is no danger that the layer

  of ceramic particles 2 constituting the protection

  However, there is no danger that individual ceramic particles 2 will come off, so that we have a

  duct having a very reliable ceramic coating.

  Since, owing to the materials used, the ceramic particles 2 can also be uniformly distributed on the inner surface of the casing tube 1, even if there is already plastic resin capable of flow or rubber capable of flowing on this inner surface, the method can also be carried out according to an alternative which consists in introducing a mixture of ceramic particles and resin of

  plastic material or rubber in the tube-enve-

  loppe, or first the plastic resin or the rubber, and then the ceramic particles. The amounts are then adjusted so that the ceramic particles, due to the centrifugal force, tend to move radially outward and spread evenly over the inner surface of the tubeawrap, no longer

  protruding only slightly from bed 3 inwards.

  Although the above description concerns

  the manufacture of a duct having a single layer of ceramic on the inner surface of the duct it

  It is also possible to provide several layers.

  Obtaining the coating 6, by means of the

  centrifugal force, represents a process of

  simple and inexpensive, which can be used

  also for small diameter ducts.

Claims (13)

  1 conduit for flowable and highly abrasive media, characterized in that the surface   inside of a tube-envelope (1) is lined with   coating (6) consisting of at least one layer of   ceramic particles (2) embedded in a bed (3) of plastic or rubber.   2 Conduit according to claim 1, characterized   characterized in that the ceramic particles (2) are spherical.   Conduit according to one of the claims   previous ones, characterized in that the particles of   ceramic (2) have a maximum dimension is between 3 and 10 mm approximately.   Conduit according to one of the claims   in that the ceramic particles (2) are arranged, for each layer, in   a layer thickness of about 3 to 10 mm.   Conduit according to one of the claims   preceding, characterized in that the ceramic material   that is selected from the group which comprises aluminum oxide, silicon nitride, silicon carbide, zirconium dioxide, or materials having similar properties.   Conduit according to one of the claims   previous, characterized in that the bed (3) is selected from a group of materials which comprises natural or synthetic rubber, urethane resins, epoxy resins or acrylic resins.   Conduit according to one of the claims   -précédentes, characterized in that the tube-envelope   (1) is made of metal or plastic.   8 Method for manufacturing a conduit according to claim 1, characterized in that it consists in rotating about its longitudinal axis a   tube-envelope (1) and to be introduced into the tube-enve-   lopper, plastic resin or rubber   in the flowable state, and ceramic particles (2), to give the casing tube (1) a rotation speed so high that the ceramic particles (2) apply, under the influence of force   centrifuge, against the inner surface of the tube-enve-   loppe (1), and continue rotating the tube   veloppe (1) until hardened or vulcanized   plastic resin or rubber.   Process according to claim 8, characterized   rised in that it consists in introducing first into the tube-   spherical, or at least substantially spherical, ceramic particles and, subsequently, when the ceramic particles (2) have been evenly distributed over the inner surface of the   tube-envelope (1), to introduce plastic material   that or rubber in the tube-envelope.   Process according to one of the claims   8 or 9, characterized in that it consists in adjusting the   amount of rubber, resin or plastic material   ceramic particles protrude only slightly from the bed (3) of rubber or plastic resin which is form.   Process according to one of the claims   8 to 10, using a heat-curable resin of plastic, or hot-vulcanizable rubber, characterized in that it consists in heating the shell-tube (1) until hardening or until vulcanization of the resin of plastics material or rubber.   Process according to one of the claims   8 to 11, characterized in that it consists, before the in-   troduction of the ceramic particles (2) and rubber or plastic resin, to provide the jacket-tube (1) at both ends of annular disks (4) which project radially   inwards, all the way inside the tube-   envelope (1) at least of a value corresponding to the layer thickness of the coating (6) to be produced and which are removed again after curing or after vulcanization.