DE2830687A1 - THERMAL INSULATED METALLIC PIPELINE INSTALLED IN THE FLOOR - Google Patents

Description

The invention relates to thermally insulated laid in the ground metallic pipeline for temperature-maintaining transport of preferably hot fluids.

Pipelines for temperature-maintaining transport of vorzugsvjeise are hot Fluids must meet two requirements in particular:

On the one hand, they must be protected against corrosion and, on the other hand, they must be thermally insulated.

Corrosion of the metallic pipelines as a result of chemical or Electro-chemical processes can be explained by the tried and tested electrical Avoid cathodic protection. However, the outer ends are insulated Systems: such metallic pipelines, e.g. B. wrapping with a Polyurethane layer so far not completely satisfactory because this is heat-insulating Sheath forms an outer insulating sheath through which the protective currents cannot penetrate. On the other hand have Changes in temperature of the conveyed material result in changes in length of the metallic pipeline, which in turn changes in cross-section and shear forces in the heat-insulating jacket.

The invention seeks to avoid this deficiency and suggests an im Metallic and thermally insulated pipeline laid in the ground, which, like pipelines without heat insulation, can be used to protect against corrosion using Cathodic protection can be protected.

According to the invention, the metallic pipeline consists of two coaxial ones Metal pipes, of which the inner pipe is used as a delivery pipe, while the outer pipe, which is in contact with the ground, is protected by cathodes is protected against corrosion.

According to a further development of the invention, the space closes between a liquid or solid material, the heat-insulating material, into the two tubes

80988S / 0830

Has properties.

In the following, the invention is intended to be based on examples of use will be explained in more detail with reference to the drawings. The drawings show in

1 shows a longitudinal section through a pipeline according to the invention;

FIG. 2 shows a cross section along the line AA ¹ of FIG. 1;

FIGS. 3 and 4 each show a partial longitudinal section through one compared to FIG. 1 modified embodiment;

5 shows a longitudinal section through a further embodiment; and in

FIG. 6 shows a cross section along the line BB ¹ in FIG. 5.

The-Fig. 1 to 4 show a first embodiment / primarily is intended for the transport of fluids with low thermal conductivity. The pipeline consists essentially of a non-tight inner pipe 1, in which the fluid is conveyed, and a tight outer tube 2, which is not in direct contact with the inner tube and is coaxial this is held by a system of spacers 3. These spacers delimit between the two pipes 1 and 2 which are cut off Channel-like spaces 4. Holes 5 allow a static Pressure equalization and are distributed over the inner tube 1 so that the conveyed fluid can penetrate into the spaces 4. The spacers 3 are welded onto the inner tube, but not onto the outer tube, so that the outer tube has a certain amount of play on the spacers 3. The spacers 3 form circular partition walls which limit a longitudinal movement of the fluid in the chamber-like interspaces 4. The fluid cushions in these spaces 4 thus take on the task the thermal insulation. In each spacer there are openings 6 for filling

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283Q687 5

of the various intermediate spaces 4 are provided. The inner tube 1 is used exclusively for guiding the fluid flow and possibly for guiding cleaning devices. Its wall thickness can therefore be small because it does not have to withstand any great internal pressure; this balances out through the holes 5 on both sides of the inner tube. The inner pipe elements are welded together. The pipe is therefore exposed to compressive forces as a result of stretching when the temperature rises or pipe shafts. In the latter case, the shaft overlaps very far in order to reduce the elongation Give game. In the case shown in Fig. 3, the Schaf device is inside and thus protects against any additional pressure due to the kinetic energy of the liquid. The case shown in FIG. 4 is located the creation on the outside, which facilitates any cleaning. Recognizable a circular spacer or partition near each shaft forms a stop that is subject to axial movement which opposes the inner pipe elements during a possible cleaning of the pipeline. In contrast, the outer tube 2 is a fluid pressure exposed to corresponding internal pressure. Its wall thickness, especially the upper one, depends on this pressure. The tubular elements that make it up are welded together at their ends. The welds of the inner pipe and the outer tube can be offset from one another. The outer pipe, which is in contact with the ground, is, as already described, against Corrosion protected by cathodic protection.

It can be seen that the spacers forming the disk-shaped partitions divide 3, which ensure the coaxial structure of the two tubes, the chamber-like spaces 4 from. Against the spacer 3 is on the outer tube a plastic shell 7 attached, the one hand the tightness when possible very small pressure differences between two adjacent chambers guaranteed, and on the other hand as a result of the induced Channeling is just as easy a filling of the chambers as the inner pipe and thus pressure equalization on both sides of the inner pipe enables. The pipes are filled from the right-hand end of FIG. H. opposite to the operating flow and cleaning device, such as it is indicated by an arrow inside the tube 1. It will

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at the same time the tube 1 and the spaces are filled. As a result of the in openings 6 provided for each spacer 3, the liquid penetrates one after the other into the various interstices, the Plastic trays 7 become stronger and stronger during the filling process due to the excess pressure of the liquid acting against the spacers press against the spacers. In this way the entire length of the pipe and all spaces are filled with fluid, so that the conveyance can go in the pipe 1 in the direction of the arrow, the liquid pressure in the spaces 4 now all the shells 7 against the spacers 3 presses and thus closes the openings 6.

The apparatus described above with respect to Figures 1 through 4 is useful z. B. for oils and fuels and generally for all fluids with low thermal conductivity. However, the transport is limited to medium distances, which distances can be increased by increasing the thickness of the spaces.

FIGS. 5 and 6 show a further exemplary embodiment of a pipeline, which are especially designed for the transport of liquids with fairly high thermal conductivity is determined.

In this case the inner tube is tight. The elements that make it up are welded together at the ends. There are also disks 8 made of metal ο at intervals. Like. Attached from one or consist of several parts and hold the inner tube 1 in the outer tube 2 and center. The disks 8 are provided with small openings 9. the The wall thickness of the inner tube 1 depends on the internal pressure of the fluid flow being conveyed and on the deflection it has to withstand between two successive discs, as well as on the compressive load that is caused by the elongation occurs during commissioning. the Pipes 1 and 2 and the disks 8 delimit intermediate spaces 10, which are filled with a solid or flowable substance which has the task of a heat insulator, are filled. The fluid can be air or a neutral gas, ζ. Β. nitrogen which can be used for a permanent density control by measuring the conservation of the mass. In certain cases it is

part way around a heat insulating material that is in these spaces is housed, e.g. B. Polyurethane / which is injected through holes that clog when inflated and polymerize, or that on the inner tube is lined up in the form of semi-cast shells, or finally around a two-component flocking agent that is mixed before assembly of the outer tube and is applied.

You can also use both insulation methods at the same time to improve the insulation to improve and. check the tightness by measuring the conservation of the mass of the gas.

The outer tube 2 is therefore also tight. Because the inner surface only the gas pressure is exposed in the interstices, the wall thickness is less. The ends of the conveyor elements are welded to one another. Between the welding plane of the inner tube and that of the outer tube is one sufficient offset is provided to cover the unavoidable differences in length balance the pipe. The inner pipe in contact with the ground is protected against corrosion by cathodic protection.

The device described with reference to FIGS. 5 and 6 is used for fluids, such as water, superheated steam and generally very high fluids Thermal conductivity use. The transport can take place over distances comparable with conventional heat-insulated pipes.

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Claims (5)

Ηβίηβ 1, 8000 Munich 40, SchäferstraBBie PMnI Inn DU Dak » EIsenacher Straße 17 P.O. Box 1140 Uipi.-IIig. H. Π. ΒαΠΓ Pat. Betzier Pat. Harrmann-Trantepohi DInI-PflVQ Eduard Rpt7ler Telephone: 089/38 3011 Telephone: 0 2323/51013 ι # ιρι. riiys. euuoiu ocuici 363012 ⁵¹⁰¹⁴ Dipl.-Ing. W. Herrmann-Trentepohl 3β 30 « Telegram address: Telegram address: Bahrpatente Herne PATENTANWÄLTE Babetzpat Munich Telex 08 229 853 Telex 5215360 Γ ~ l bank accounts: Bayerische Vereinsbank Munich 952287 Dresdner Bank AG Herne 7-520499 Postal check account Dortmund 55868-407 L J ^Ref "M 06352 B / h. Please indicate in the answer Please send a letter to: Munich July 11, 1978 SOFITBC (S.A.R.L.), 14 rue Bezout, 75014 Paris (France) Annie Brun, rue du Pie du Midi, 31240 L'Union (France) Raymond Arsenne, rue du Villard, Chapareillan 38530 Pontcharra (France) Heat-insulated metallic pipeline laid in the floor Claims Heat-insulated metallic pipeline laid in the ground for the temperature-maintaining transport of fluids on the outer surface is protected against corrosion by cathodic protection and the that Thermal insulation surrounding fluid-carrying pipe is optionally provided with a coating, characterized in that a second tight outer metal pipe (2) is provided coaxially with the first pipe (1) over the thermal insulation and the cathodic protector against corrosion instead of an accidental effect on the outside of the To produce thermal insulation, on the outer surface of the entire thermally insulated Conveyor pipe encased second tight metal pipe acts. 2. Pipeline according to claim 1, characterized in that that when transporting a fluid with low thermal conductivity this even to take on the role of the heat-insulating material, the spaces (4) located between the tubes (1, 2) via the interior 8098SS / 083Ö ~ ² ~ ORIGINAL INSPECTED tube (1) fills provided holes (5) under the static pressure. 3. Pipeline according to claim 2, wherein the spacer for the outer tube with openings for filling kairmers between the outer and inner pipe are provided, characterized in that on the outer edge of the spacer (3) plastic shells (7) for closing the openings (6) are attached. 4. Pipeline according to claim 2, characterized in that it consists of welded together outer pipe elements (2) and inner pipe elements (1) exists, which deals inside or outside the pipe are. 5. Pipeline according to claim 4, characterized by a supporting spacer (3) in the vicinity of each pipe shaft for Formation of a stop that allows axial displacement of the inner tube elements (1) counteracts any cleaning of the line.