DE2746180A1 - Composite plastics-insulated pipe - comprises mantle shaped from a strip, particulate insulating material, and coaxial inner pipe - Google Patents

Abstract

Pipe(s) systems are continuously (plastics-) insulated within a continuously operating pipe-moulding, pipe-welding and pipe-drawing installation. The insulating material is poured cold, in the form of granules or powder onto a cold moving band. Onto the treated band for the mantle pipe, a 2nd inner pipe is placed moving at the same speed. The thickness of the insulating layer equals dia. of mantle pipe minus dia. of inner pipe. The bond is then longitudinally curved to form an almost closed (i.e. narrowly slotted) pipe where additional insulating material is poured in so that a space of about 2mm. is left between insulation and upper inner wall of the pipe after it has been seam-welded. This space is later eliminated when the pipe is reduced in the draw ring of the continuously operating drawing installation, thereby compressing the insulation. This causes the insulation to bear firmly against the inner pipe and prevents formation of voids. Instead of a single inner pipe, several smaller pipes or heating wires or rods may be embedded in the insulating material inside the mantle pipe. The inner pipe is centred inside the mantle pipe by means of centering pins.

Description

PROCESS FOR CONTINUOUS MANUFACTURING

INSULATED DOUBLE PIPES The invention relates to a method for continuous Production of double or multiple pipes with simultaneous insulation of these Pipes against each other.

Up to now, pipes that carry hot or cold media have been used isolated from laying. This work is extremely expensive and troublesome.

There is also a known method in which pipes with an insulating hose be coated.

The granulate used as insulating material is first heated, liquefied and by means of an expensive extrusion process onto the pipe upset. The initially heated pipe string must win the aftertreatment again be cooled to room temperature. During this process, the previously introduced one escapes Energy unused as water vapor.

The invention is therefore based on the object of providing a method in which the quality of the insulation of pipes is improved - energy-saving -and is produced more economically and at the same time produce pipe systems can.

The solution to this problem is d u r c h e k e n n n n z e i c h n e t that the insulating material as granules in a known longitudinal pipe welding machine a -shaped beef is cut and that 1. in the position in which the band is formed into a 1/2 slot tube, and 2. at the point where the slot still goes through Cutting discs is held open.

Immediately after pouring the insulating material into pos. 1, the Tube, which is the actual media carrier, continuously into the cladding slot tube and at the same speed with which the casing pipe is formed will.

If the inner pipe is to be exactly in the middle of the jacket pipe, then so the embankment height of the insulating material is to be selected according to the invention so that the: \ U Isciiiit tungshöhe plus 1/2 pipe diameter of the inner pipe of the center line of the jacket pipe corresponds with an eccentric position is the embankment height according to the invention to be selected accordingly.

The bulk material is precisely rushed out of a metering device speaking of the belt speed and the dump height.

In pos. 2, insulation material is added again and was soil, that when the slit tube is closed later in the weld gap there is a free space of 2 min remains between the insulating material and the inner pipe wall.

After the welding, the now closed pipe is replaced by a technical known, continuously working drawing system (see P 23 54.161) pulled.

According to the invention, the caliber of the drawing ring is determined in such a way that that the jacket pipe is reduced in diameter by an amount which is necessary to keep the inner tube firm and pore-free from the 1 insulating granules is surrounded.

After straightening the pipe string, which now consists of an inner roller, insulating material and jacket pipe, a technically known rotating pipe cutting device takes over cutting the pipe string into individual lengths.

Optionally, the pipe string can also be coiled into rings after being reduced will.

Instead of one thin pipe, several small ones can be rolled up will. The same applies to the curling of massive preheats or rods as heating conductors 0.

A further development of the invention also allows an inner tube to be rolled up, centered or concentrated in the jacket pipe without any insulation compound position i e it is. This type of pipe system production is necessary if, for. B. the inner tube should be slotted from loads and external damage, or if a liquid or gaseous medium is provided between the inner and outer tubes is.

The centering of the inner tube is achieved in that the inner tube is provided with clips before inserting it into the jacket tube, each with 3 thin centering points wear. These tips are the same length from the middle and are based on the Reduce the pipe evenly on the inner walls of the 1st pipe jacket, and thereby cause the inner tube to be centered.

The attached illustrations show a side view and sections the way the procedure works.

The slotted or formed from bent steel strip. Jacket pipe (1) is caused by the shaping and caliber rolls, not shown in the picture, in the direction of the arrow transported at a precisely specified speed.

In the slotted tube area of item 1, which is still open, there is a Dosing device (3) isolating agent (4) in Gl granulate or powder form on the Lower inside of the jacket pipe (1) poured Shortly after pos. 1 is the inner pipe (2) Introduced into the jacket tube (1) at the same speed and opened embedded in the insulation material embankment.

The tube (2) is preferably wound into large coils and is over technically known decoiler, smell-tind feeder in the jacket pipe (1) pushed. Insertion takes place by means of a technically known pipe supply loop of tube (2) practically endless.

In position 2, the jacket pipe (1) is already further closed and Due to the associated reduction in pipe diameter, the inner pipe (2) already surrounded by insulating granules. Through the still open slot takes place through a second granulate dosing (5) the fine dosing with granules (4) and was such, that when the jacket pipe (1) is closed in the welding area (t) the pipe (1) is not completely is filled with granules (4), so that there is still enough Ratim for proper formation the inner weld bead is present.

After the now closed pipe system has been welded, it arrives In the continuously working drawing system (@), the pipe system must be the drawing ring (8) happen. This is smaller than the diameter of the jacket pipe (1) and reduced thus the circumference of the lantern tube (1) to a value that is determined in terms of size is that by reducing the isolating agent granulate (4) is fed up with the inside Tube (2) lays and is solidified pore-free in itself.

The pipe system runs through a continuous strand that is not shown in the picture Straightening system and is in a flying pipe cutting device, also not shown Separated in commercial lengths or reeled into coils.

The sections in the drawing represent the cross-section of the finished pipe system represent.

A 5 material for the pipe system are all weldable steels, stainless steels and non-ferrous metals in question.

The material of the outer and inner tube can also be different be. The inner tube can also be made of plastic atis all features included in mentioned in the description above and / or shown in the drawing, should, insofar as the state of the art permits, flor stand alone or in any way Combination or partial combination are regarded as essential to the invention, too if they are not included in the claims.

L e r s e i t e

Claims (7)

Patent claims 1.) Process for the continuous insulation of pipes by producing a pipe system within a continuously operating pipe mold - Pipe welding and drawing system characterized in that the insulating material in Form of granules or powder in the cold state in item 1 to the cold, unprepared, running belt is poured. 2.) The method according to claim 1, characterized in that on the Tape equipped with insulating material for the jacket pipe (1) in a second inner pipe (2) is placed and with the same feed rate as the jacket pipe (1) pretends. 3.) The method according to claim 1 and 2, characterized in that the Height of the heaped insulation material with the relationship between the heap height = D pipe (1) - D corresponds to pipe 2. 4.) The method according to claim 1, 2 and 3, characterized in that at pos. 2 in the almost closed jacket pipe (1) as much more insulating material is poured that in the later closed profile in the welding area a free one Space of approx. 2 mm between the bulk material (4) and the upper, inner pipe wall of the pipe (1) remains. 5.) Method according to claim 1, 2, 3 and 4, characterized in that that the jacket tube (1) in the drawing ring (8) of the continuously operating drawing system (7) is reduced to such an extent that the free space between the bulk material (4) and the pipe wall of the jacket pipe (1) is removed and the insulating material (4) is so tightly compressed, that it first and foremost lies around the inner tube (2) and secondly in itself shows no loosening or coarse pore formation. 6.) Method according to claim 1, 2, 3, 4 and 5, characterized in that that instead of the single inner tube (2) several small tubes, or individual or several heating wires or rods inside the jacket pipe (1) in the insulating material (4) be embedded. 7.) A method for producing pipe systems, characterized in that that an inner tube (2) is introduced into the running jacket tube (1) and that the centering of the tube (2) is done by means of attachable centering pins (9), whereby the space between pipe (1) and pipe (2) remains empty.