LU81803A1 - DEVICE FOR COATING THE EXTERNAL SURFACES OF TUBES - Google Patents

Description

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Device for coating the outer surfaces of pipes

The present invention relates to a device for coating the outer surfaces of steel or cast iron pipes, in particular with concrete. 5 Steel pipes laid in the ground or under water are increasingly provided with concrete coatings, which, depending on whether mechanical protection, protection against corrosion or a combination of both effects is aimed for, to a greater or lesser extent. For example,

10 steel pipes of approx. 1 m in diameter, which are intended for the transport of gas under still or flowing water, are to be provided with a 5-12 cm thick concrete jacket. The latter is intended to protect the pipe string against corrosion, as well as against pressure and impact loads; it should also serve as a weight and counteract the buoyancy that would cause breakage in flowing or moving water.

To apply thick layers of concrete to large-caliber pipes (diameter approx. 1 m; length 10-20 m), the individual pipe segments can be rotatably supported according to the state of the art and the coating can be carried out using a nozzle which moves along the pipe axis, whereby the concrete - 2 - is applied in successive layers of 6-10 mm thickness.

As a result of the tube mass, considerable effort is required to turn the tube segment. It must also be noted that the multi-layer application technology on the one hand brings uneven surfaces of the finished concrete layer with it and, on the other hand, which is much more serious, often leads to the flaking of the concrete from the substrate due to the inhomogeneity of the coating.

Attempts have been made to counteract this by inserting expensive reinforcements made of wire into the concrete layer, which has proven to be unfavorable as a result of wire protruding from the concrete surface, and by adding glass fibers to the concrete, which has a positive effect on the cohesion of the coating impacted, but brought with it certain costs.

20 In order to avoid these problems, it was proposed to encase the pipes in vertical forms, which is unrealistic for pipe segments of 10-20 m in length with regard to the forms to be used. Furthermore, such a procedure would entail that there would be a considerable pressure difference between the bottom and 25 uppermost layers of concrete in the molds, which would undoubtedly lead to inhomogeneous conditions in the quality of the coating from one pipe end to the other.

30 The aim of the invention was therefore to develop a device which allows simple and problem-free coating, in particular of large-caliber pipes, and which does not have the disadvantages mentioned.

35 This goal is achieved by the device according to the invention, which consists of an essentially stationary shape and which is characterized in that a lining consisting preferably of a steel sheet forms a shaped base which is essentially circular segment-shaped in cross section and which has at least two mutually independent and spaced-apart supports in form 5 of essentially semicircular support frames, the support frames preferably being equipped on both sides with circular segment-shaped arms also having a lining which can be opened and closed and, in the closed state, delimit a circular shape .

• 10th

The idea on which the invention is based is based on the fact that it is extremely expensive to build and maintain suitable solid forms for coating large-diameter pipes of different lengths and diameters, while it is probably both expensive and technically difficult to manufacture systems, which would have the flexibility required for coating different pipes.

Instead of providing an expensive, adjustable shape, the invention provides for a large number of circular segment-shaped profiles of relatively low weight and of suitable geometry, which, when arranged in a meaningful manner on various, cheap supports, can represent any desired mold base.

25th

In the case of particularly long pipes to be coated, several series of chucks can be lined up lengthwise, a support frame which is usually somewhat wider being placed under the border point between two chucks.

30th

According to the invention, a support frame consists of a sheet metal which has a semicircular incision and which is fastened to a stand approximately in the form of a broad U-shaped support. On both sides of the incision, wings are attached by means of joints which serve as a lining and which can be folded down.

A

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To prevent the concrete layer from adhering to the forage, the latter is covered with a plastic film or special paper.

5 A favorable embodiment provides that both the liners resting on the support frames and the liners attached to the wings represent circular segments of 110 °. When the mold is closed, there remains an upper opening of 30 ° for the feeding of concrete.

10 *

The device also understands two end supports which are adjustable in height and which engage at the free ends of the pipe to be coated. In fact, concrete-free zones are left at the pipe ends, since the individual pipe segments 15 must be welded together before laying. The supports are attached to these ends and the height is adjusted so that the thickness of the concrete layer to be attached is achieved in relation to the height of the individual support frames and the lining lying on them.

20th

The device according to the invention has the advantages of a simple modular system, moreover it is extremely easy to maintain, since cleaning is limited to individual feeds, which are also made of plastic or

25 sheets of paper are protected.

Further advantages and features will become apparent from the description of the drawings, in which FIG. 1 shows a cross section through the device according to the invention, while FIG. 2 shows a schematic longitudinal section through the entire device.

In Fig. 1 you can see the pipe to be coated (o) which is stored at a distance corresponding to the concrete layer thickness above the 35 lining (30), which rests on the support frame (10). The support frame (10) has a semicircular incision (11) and two wings (20) which are fastened to the steel sheet forming the frame (10) by means of coulters (21).

The putter (30) is covered 5 with a film, not shown, and the concrete is poured. During pouring, the concrete (2) can be treated at the same time by means of a vibrator (1) that can be moved in the pipe. A rod-shaped vibrator can also be inserted into the concrete during pouring. After the potting process has progressed, the wings (20) are now also folded over / with locking means (not shown) determining the end position of the wings (20). Of course, at the apex of the pipe (0) there remains a free zone in the longitudinal direction to the pipe axis for filling in the concrete and possibly for inserting the vibrator.

15

At the ends of the pipes, the lining is sensibly limited by means of sheet metal rings that prevent the concrete from seizing out laterally.

20 Fig. 2 shows the entire device with the exception of the adjustable end supports. The mutually independent support frames (10) with their wings (20) and the sheet metal rings (40) can be seen.

Since the entire device according to the invention consists of 25 parts that can be put together, it can also be easily transported and operated at any location in connection with a concrete and pouring system.

Claims (6)

1. Device for coating the outer surfaces of hollow bodies, · in particular for coating pipes with concrete, 5 which consists of an essentially stationary shape, characterized in that a lining, preferably consisting of a steel sheet, forms a cross-sectionally shaped bottom which is essentially circular segment-shaped at least two mutually independent and spaced-apart supports in the form of essentially semicircular support frames, the support frames are preferably equipped on both sides with circular segment-shaped arms also having a lining which can be opened and closed, and a 15 circular when closed Limit shape. 2. Device according to claim 1, characterized in that a plurality of chucks are lined up lengthwise, a supporting frame with a usually broader contact surface being underlaid at the border point between two chucks. 3. Device according to claims 1-2, characterized in that the support frames have a semicircular cut and are carried by a stand in the form of a 25 wide U-shaped support. 4. Device according to claims 1-3, characterized in that the lining is separated from the concrete layer by a plastic film or 30 by special paper. 5. Device according to claims 1-4, characterized in that both the resting on the support frame and the lining attached to the wings represent circular segments of 110 ° 35. 6. Device according to claims 1-5, characterized gekennzeich- - 2 - «that the pipes to be coated rest on two acting on the pipe ends, independent of the support frame and height-adjustable supports.