NL8301021A - Roughening procedure for ballasting smooth underwater circuits - has irregular particle implanted in resin before polymerisation - Google Patents

Abstract

The procedure fixes a layer of ballast in concrete or other material onto smooth extruded synthetic resin protective covers of metal underwater tubes (2). The ballast forms multidirectional anchoring points with a uniform hold along the total length of the tubes. Before cooling or polymerisation of the synthetic resin (1), finely divided particles of the same resinous material (3,4,5) are placed and welded by their base (6) to form reliefs and cavities (7,8) of different volume and irregular profile. The particles can be sawdust, glass beads or other metal or synthetic material.

Description

«Device enabling the attachment of a ballast to the plastic coatings to protect the pipes intended to be immersed as well as the manufacturing method thereof.

. The invention relates to a device that allows the attachment of a ballast to the plastic liners for protecting pipes intended to be immersed as well as to the manufacturing method thereof.

The object of the invention is to provide an adhesion surface to ensure the hooking of the weighting concrete coating to ensure the stabilization on the bottom of the submerged nsea lines, the coating of which is formed by an extruded or powdered and smooth layer. synthetic resin of high, medium or low density polyethylene. j

In the known devices, attempts were made to slide or; avoid moving the concrete ballast by using thickening of the extruded polyethylene coating in place of the thickness differences or over-thicknesses formed by the webs and so left during manufacture; however, the immersion depths increasingly important on which the "sea lines" must be placed, requiring an increasingly important tension, are transferred to the anti-corrosion and ballast coatings.

The synthetic resin coatings of extruded or powdered polyethylene have an adhesion better than the coal tar or bituminous coatings which have hitherto been used to protect the tubes.

It has further been found that a concrete ballast fabricated on a coal tar or bitumen coating and corresponding to a concrete slip resistance of 3 kg / cm approximately is not improved in adhesion performance when applied to a coating of extruded polyethylene 35 with excess thickness limited to the webs.

On the other hand, the resistance to sliding of the concrete 2 can reach approximately 10 kg / cm when the bonding surface is improved on the coatings.

The device according to the invention allows 8301021 * -2.

"To obtain all-directional anchoring points on the smooth surface of the polyethylene cladding that provide a roughness that ensures a hooking of the concrete.

Spraying is formed on the entire surface of the extruded polyethylene coating or formed by any other coating process for cooling or complete polymerization, protrusions provided by particles of synthetic resins or other substances such as sand, sawdust, glass beads stick, crust or weld onto the receiving surface.

In certain applications, in particular on the coating of extruded or powdered polyethylene, a mechanical method is used to favor the compound of the sprayed powder on the coating.

The invention will be explained in more detail below with reference to the drawing, in which an embodiment according to the invention is shown by way of example.

1-3 show the products obtained in section and in elevation; Fig. 4 shows an experience method of the hooking device.

The surface of polyethylene, which forms the protective layer 1 of the metal tubular element 2, which is used for the production of the "sea lines" or submerged pipes, is completely smooth. The coating of this surface by the concrete was retained only by the thickness differences of the webs at each of the ends. This resulted in an absence of adhesion over the entire length. As a result of the effects of the capacity of surface tension and even shocks, disintegration movements arose which deprived this ballast of its effectiveness in its ballast and protection function.

These drawbacks have been avoided by manufacturing on the surface 1 of attachment points 3,4,5 in a homogeneous distribution as a whole in terms of their distribution, but without any homogeneity in their distance from anchoring, direction and height so that in all directions hooking bonding surfaces are formed.

Using freely distributed particles of synthetic resin 40 of the same type (fig. 1), these melt more or less sharply 8301021 - J - -

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The protruding hooking points in their contact surface 6 so that a monolithic bed is thereby formed thereby creating a relief.

This unevenness and roughness allow the concrete or other amalgam to insert between these concave spaces 7/8.

The same resin profiles such as epoxy, polyamide etc. used in liquefied baths by the electrostatic powder or spraying by applying to these surfaces 10 of finely divided mineral particles 9,10, whose bases 11,12 are sufficient in the absorbing, not yet distributed surface penetrate, that is, before polymerization,

Spheres of glass 13,14 and similar elements with the same functions can also be applied to these surfaces.

The methods used for these fabrications can be adapted to the shape of the steel pipes, either by rotating and shifting the latter or by shifting and rotating the spraying and / or application equipment.

Preferably, to ensure the distribution of the anchoring particles on the surface 16 covering the tube 17, which performs a sliding and twisting movement, a spray gun 19 is used, which draws the material into the reservoir 18 by compressed air 20, supplemented by a mechanical pressing device 21.

This gun is connected on the one hand to the reservoir 18, which contains the product to be sprayed, and to the compressed air generator 20, so that the particles are driven to be moved on the unpolymerized synthetic resin 16 and then pressed with a mechanical pressure 21 to be attached thereto through 360 ° with a homogeneous distribution in its entirety but spaced apart and an anarchic direction to provide functional irregularities.

The materials used to create the anchoring surfaces and the crusting means will be able to vary within the limit of the equivalents without therefore changing the general idea of the invention 40 just described. - Conclusions - I

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Claims (4)

1. Device permitting the attachment of a ballast layer of heton or other composition on the protective linings of extruded or powdered smooth plastic with which the immersed tubes or "sea lines" 5 are covered in order to realize anchoring points with profiles pointing in all directions, but ensure a uniformly distributed hooking along the entire length of the receiving element, characterized by implanting before the cooling or polymerization of the synthetic resin (1) of particles which are finely divided but have irregular profiles of synthetic resin of the same type (3,4,5) of sand, sawdust (9,10) or glass balls (13,14,15) or of materials of metal or plastic. Device according to claim 1, characterized in that the particles (3,4,5) of the same kind as the support (1) are welded to their base (6) and reliefs and cavities (7,8) shapes of different volume with irregular profiles. Device according to claim 1, characterized in that the particles of different materials, sand, minerals, vegetable material and the like (9,10) or of spheres (13,14,15) are anchored in the not yet polymerized synthetic resin (1) by more or less deep penetration (11,12) so that irregular cavities and protrusions are formed as far as their implantation is concerned but a uniform distribution takes place throughout. Device according to claim 1, characterized in that the sprayed particles are seranched by a mechanical pressing device (21). 8501021