EP2643631B1 - Pipeline for conveying liquefied gas - Google Patents

Description

The invention relates to a pipeline for conveying liquefied gas, in particular to so-called LNG tankers, so tankers for the transport of liquefied natural gas, according to the preamble of claim 1.

So far, such LNG tankers have only been driven in waters at temperatures above 0 ° C or in light frost. In the future, LPG will also be transported in Arctic waters. As a result of the low air temperatures down to -50 ° C associated with high humidity and the spray, a thick layer of ice is formed on the equipment on a ship's deck. This is particularly disadvantageous for LNG pipelines. The thickness of a layer of ice on the pipes means that the functionality of fittings and the strength of the pipes due to the ice load are no longer guaranteed.

From the WO 98/59084 A1 a pipeline of the generic type is known which has no measures to prevent ice formation on the pipes.

In the report of the US Army Corps of Engineers Engineers Research and Development Center "Assessment of Superstructure Ice Protection as Applied to Offshore Oil Operation Safety", September 2008, ERDC / CRREL TR-08-14 It is described that it is generally known to cut ice on the lines and fittings with hammers. In order to avoid the damage occurring and the great effort required for this purpose, it has been proposed to surround the components located on the ship deck with plastic plates and to defrost them in some form by vibration. This technology has been found unsatisfactory.

The invention is therefore based on the object to prevent the formation of ice on the pipes and to facilitate ice removal.

This object is achieved by the features of claim 1. The vibrating tube surrounds the pipe provided with a cold insulation for the transport of liquefied gas at a distance, so that a cavity is formed. The vibration tube itself can ice. It is freed from the ice by the vibration. The only in each case partially formed vibration tubes are connected to each other according to claim 1 by means of a sliding connection, which may be formed according to claim 3 as a vibration tube connector shell. According to claim 4, the tube is supported in the region of the sliding connection by means of a bearing on the ground.

A reliable vibration transmission from the vibrator to the vibration tube is ensured by the measures according to claim 5. An advantageous embodiment of the vibration generation and transmission results from the claims 6 to 10.

Fig. 1

eine LNG-Rohrleitung mit Vibrations-Umhüllung in Seiten-Längsansicht,

Fig. 2

einen Querschnitt durch die Rohrleitung im Bereich eines Lagers entsprechend der Schnittlinie II-II in Fig. 1,

Fig. 3

einen Längsschnitt durch die Rohrleitung im Bereich eines Lagers entsprechend der Schnittlinie III-III in Fig. 2,

Fig. 4

einen Querschnitt durch die Rohrleitung benachbart zu einem Lager entsprechend der Schnittlinie IV-IV in Fig. 3,

Fig. 5

eine Einzelheit entsprechend V in Fig. 4,

Fig. 6

einen Querschnitt durch die Rohrleitung im Bereich eines Vibrators mit Vibrationsringen entsprechend der Schnittlinie VI-VI in Fig. 1,

Fig. 7

eine Einzelheit entsprechend VII aus Fig. 6,

Fig. 8

einen Querschnitt durch die Einzelheit VII in Fig. 7 entsprechend der Schnittlinie VIII-VIII in Fig. 7,

Fig. 9

eine Draufsicht auf eine Rohrleitung mit einem Rohrbogen,

Fig. 10

eine Draufsicht auf eine Rohrleitung mit einem Rohrabzweig und

Fig. 11

eine Rohrleitung mit einer Armatur in Seiten-Längsansicht.

Further features, advantages and details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing. It shows

Fig. 1

an LNG tubing with vibration enclosure in side longitudinal view,

Fig. 2

a cross section through the pipeline in the region of a bearing according to the section line II-II in Fig. 1 .

Fig. 3

a longitudinal section through the pipeline in the region of a bearing according to the section line III-III in Fig. 2 .

Fig. 4

a cross section through the pipeline adjacent to a bearing according to the section line IV-IV in Fig. 3 .

Fig. 5

a detail corresponding to V in Fig. 4 .

Fig. 6

a cross section through the pipeline in the region of a vibrator with vibrating rings according to the section line VI-VI in Fig. 1 .

Fig. 7

a detail corresponding to VII Fig. 6 .

Fig. 8

a cross section through the detail VII in Fig. 7 according to the section line VIII-VIII in Fig. 7 .

Fig. 9

a top view of a pipeline with a pipe bend,

Fig. 10

a plan view of a pipeline with a branch pipe and

Fig. 11

a pipeline with a fitting in side longitudinal view.

As the Fig. 1 and 2 can reveal, laid on a deck 1 of a ship or other underground LNG pipe on a LNG pipe 2 with a cold insulation 3 of insulating material, which is to prevent heat flow from the outside into the pipe 2. The abbreviation LNG pipe 2 is used below for a pipe in which liquid Natural gas is promoted. LNG stands for Liquid Natural Gas. The sheathed with the cold insulation 3 LNG pipe 2 is in turn surrounded by a designed as a vibration tube 4 protective tube or sheath that - such as Fig. 4 and 6 can be removed - has radial distance to the cold insulation 3, so that a substantially annular cylindrical, filled only with air cavity 5 is formed. There is no physical connection between the vibrating tube 4 and the LNG tube 2. The vibration tubes 4 are formed by half shells 6, 7 consisting of sheet metal, which are connected to one another by means of a flange connection 8, such as Fig. 4 is removable.

Since the half-shells 6, 7 have a finite length, they are each connected to each other by means of a pipe-section-shaped vibration tube connector shell 9, in which the individual, formed by interconnected half shells 6, 7 sections of the vibrating tube 4 are guided sealed in the manner of a sliding bearing , as Fig. 3 is removable. The vibrating tube connector shells 9 in turn consist of connector half-shells 9a, 9b, which are interconnected by means of flange connections 9c.

As Fig. 3 can also be removed, have the guided in the connector shell 9 sections of the vibrating tube 4 end-to-end distance from each other. In this space, a bearing 10 is arranged for the covered with a cold-insulation 3 LNG pipe 2, the lower half-bearing shell 11 and the upper half-bearing shell 12 surround the sheathed with a metal jacket 3 a cold insulation 3 and by means of a flange 10a are interconnected. The lower bearing half-shell 11 is slidably supported on the deck 1 by means of a bearing shoe 13. The bearing shoe 13 passes through a lower opening 14 in the connector shell 9, where an ice water drain 15 is provided as well Fig. 2 is removable.

Each approximately centrally between two bearings 10 of a lower half-ring 16 and an upper half-ring 17 existing vibrator ring 18 is arranged, which is fixedly connected to the half-shells 6, 7 of the vibrating tube 4, as seen from Fig. 6 is apparent. The half shells 6, 7 and the half rings 16, 17 are - as in particular from Fig. 7 can be seen - connected together in a common flange 19. Between the half-rings 16, 17 and the half-shells 6, 7 there is full-surface physical contact, for example, by a welded connection 20 of the existing half-shells 6, 7 and half-rings 16, 17 (s. Fig. 8 ).

On the vibrator ring 18 designed as a commercial pneumatic vibrator vibrator 21 is arranged, which is fixedly mounted on a support plate 22, which in turn is in fixed vibration connection with the upper half-ring 17 of the vibrator ring 18. Vibrations of the vibrator 21 are thus transmitted to the vibrator ring 18. The vibrator 21 is surrounded by a vibrator housing 23 as a protective housing. The compressed air supply to the vibrator 21 via a compressed air main line 24 which is arranged in the cavity 5 and is guided through the entire pipeline. To each vibrator 21 performs a compressed air connection line 25. From the vibrator 21 again leads an exhaust duct 26 into the open.

As Fig. 6 is removable, the vibrator ring 18, namely the lower half-ring 16, supported by a rubber buffers 27 existing bearing 28 on the deck 1, wherein the rubber buffer 27 in turn at a lower Supporting support plate 29, which is attached to the lower half-ring 16 of the vibrator ring 18.

In each case between adjacent bearings 10 of the LNG tube 2, that is, between two mutually adjacent vibrating tube connector shells 9, a vibration unit 30 is formed, which is substantially the corresponding portion of the vibrating tube 4, the vibrator 21 with vibrator ring 18th and the associated details. Such a vibration unit 30 is supported via the vibrator ring 18 and the bearing 28 at its center.

If a pipe bend 31 is provided in the course of the pipeline, then a bearing 10 of the LNG pipe 2 is provided on one side of the pipe bend 31. The envelope of the LNG tube 10 by a correspondingly curved tube pipe 31 vibration tube 32 is formed at the ends of each as a sliding bearing 33, 34, that is as in the area of the vibration tube connecting shells 9. As further Fig. 9 can be removed, the arrangement is such that the vibrators 21 are arranged with vibrator rings 18 on the straight pipe sections immediately adjacent to the two ends 35, 36 of the curved vibration tube 32.

If - according to Fig. 10 - The LNG pipe 1 has a branch pipe 37, a so-called T-piece, then the corresponding pipe branch vibration tube 38 at all three ends 39, 40, 41 in principle like a sliding bearing 42, 43, 44 is formed. Adjacent to all three ends 39, 40, 41 vibrator rings 18 are arranged with vibrators 21 in the vibrating tube 4 and in the two branching vibrating tubes 4a and 4b. The branch pipe vibration pipe 38 is supported in the region of its end 39 adjacent to the LNG pipe 2 via a bearing 10.

If - according to Fig. 11 in the LNG pipe 2, a valve 45, so a valve or a slider is arranged at both ends of the fitting 45 surrounding insulating housing 46 each have a fitting-vibration tube 47, 48 are provided, which the adjacent vibration Pipe 4 in the manner of sliding bearings 49, 50 record. Both armature vibration pipes 47, 48 are each supported by bearings 10 on the deck 1. Adjacent to the ends 51, 52 of the fitting vibration pipes 47, 48 are provided on the vibrating tubes 4 opening into them vibrator rings 18 with vibrators 21, so that the hollow insulating housing 46 can be set in vibration. To operate the valve 45, the insulating housing 46 has a removable cover 53.

By putting the vibrators 21 into operation, the vibration tube 4 and possibly the curved vibration tube 32, or possibly the tube branch 37 and the tube branch vibration tube 38 and possibly the insulating housing 46 are set in vibration by the on ice is removed and removed.

Claims (10)

1. Pipeline for conveying liquefied gas,

   - with a pipe (2), which is encapsulated by a cold insulation means (3) and supported relative to a subsurface,

   characterized by

   - vibration pipes (4) surrounding the pipe (2) at a spacing and

   - a vibrator (21) attached to each vibration pipe (4).
2. Pipeline according to claim 1, characterized
   in that mutually adjacent vibration pipes (4) are connected to one another by means of a slide connection.
3. Pipeline according to claim 2, characterized
   in that the slide connection is configured as a vibration pipe connector shell (9).
4. Pipeline according to claim 2 or 3, characterized
   in that the pipe (2) with cold insulation means (3) is supported on the subsurface by means of a bearing (10) passing through an opening (14) of the slide connection.
5. Pipeline according to any one of claims 1 to 4, characterized
   in that each vibrator (21) is attached to the vibration pipe (4) by means of a vibrator ring (18).
6. Pipeline according to claim 5, characterized
   in that the vibrator ring (18) surrounds the vibration pipe (4) with a vibration-transmitting connection.
7. Pipeline according to any one of claims 1 to 6, characterized
   in that the vibration pipe (4) is supported on the subsurface by means of a damping bearing (28).
8. Pipeline according to claim 5 and 7, characterized
   in that the vibrator ring (18) is supported on the damping bearing (28).
9. Pipeline according to any one of claims 1 to 8, characterized
   in that the vibrator (21) is configured as a compressed air vibrator.
10. Pipeline according to claim 9, characterized
    in that a compressed air main line (24) to supply the vibrator (21) is arranged in the cavity (5) between the pipe (2) with cold insulation means (3) and the vibration pipe (4).

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