Pipes and tubular conduits – Distinct layers – With intermediate insulation layer
Patent
1998-11-18
2000-05-30
Brinson, Patrick
Pipes and tubular conduits
Distinct layers
With intermediate insulation layer
138140, 138175, 405171, F16L 914
Patent
active
06068027&
DESCRIPTION:
BRIEF SUMMARY
This invention relates to pipeline insulation. More particularly, the invention relates to a pipeline insulation blanket, and to an insulating cell for a pipeline insulation blanket.
It is often desirable to provide insulation for undersea pipeline lying on the seabed in order to prevent heat loss. This heat loss can lead to an undesirable cooling of the fluids being transported through the pipeline. There are a number of known techniques for insulating existing or planned pipeline.
We have now found a way to provide effective insulation for a pipeline, which is cost effective to manufacture and which is easy to handle and install.
According to one aspect of the present invention we provide an insulation blanket for a pipeline, comprising at least one insulating cell, wherein the or each insulating cell comproses a protective layer and an insulating layer. The protective layer is suitably concrete, preferably high strength concrete.
The protective layer provides the rigidity to hold to blanket together, ie, it provides reinforcement for the blanket. In addition, the protective layer can protect the insulating layer from the conditions prevailing on the seabed, such as high pressure, and can protect the insulating layer from the ingress of Seawater. In the North Sea the pressure would typically be in the range 10 to 20 bar, while in the Gulf of Mexico the pressure could be up to 50 bar. The insulating layer provides the necessary insulation for the blanket.
The protective layer will usually be much denser than the insulating layer, thereby providing sufficient ballast for the blanket: typically the protective layer will have a density greater than 1.5 tonnes per cubic meter, and the insulating layer will have a density less than 0.1 tonnes per cubic meters. The density of the protective layer would usually be less than 2.0 tonnes per cubic meter,and the density of the insulating layer would usually be less than 2.0 tonnes per cubic meter.
The insulating layer is a material having a low thermal conductivity, which is preferably in the range 0.015 to 0.04 W/mK, more preferbly 0.022 to 0.039 W/mK. An example of a suitable insulating material is polystyrene foam. The thickness of the layer of concrete surrounding the insulating layer is desirably in the range 20 to 40mm, and may be in the range 20 to 30 mm.
The or each insulating cell may be provided with more than one of said insulating layers and/or with more than one of said protective layers.
Preferably the or each cell has an outer layer of a water impermeable material.
In a preferred embodiment the or each cell has the general shape of a hexagonal prism, ie a prism in which the two end faces are shaped like a hexagon. The or each cell may be interconnected along two opposite longitudinal edges of the prism.
The or each insulating cell can be suitably shaped, so that the pipeline insulation blanket can surround at least part of the pipeline.
In one embodiment, a plurality of the insulating cells are secured to one another by a flexible connector, in order to provide an articulated structure; this enables adjacent cells to pivot relative to one another. A gasket or other impermeable material may be provided in the axis of the flexible connector to help prevent water from flowing between adjacent cells. This helps to reduce heat losses.
In another embodiment, each insulating cell may comprise a segment of a circle, and the inner surface of each cell (ie the surface that corresponds to the innermost part of the segment of the circle) may be shaped to conform to the shape of the pipeline to which it is to be fitted. The blanket composes a sufficient number of the cells connected together to surround the pipeline completely. For example, if each cell corresponds to the segment of a third of a circle, then the blanket will comprise three cells. This embodiment is particularly useful when the blanket is to be installed at the same time as the pipeline.
In a further embodiment, a single insulating cell is adapted to surround the periphery of the pipeline completel
REFERENCES:
patent: 687389 (1901-11-01), Wilhelmi
patent: 1772821 (1930-08-01), Weber
patent: 2315837 (1943-04-01), Brown et al.
patent: 4228826 (1980-10-01), Campbell, Jr.
patent: 4240994 (1980-12-01), Ottenholm
patent: 4252767 (1981-02-01), Piazza et al.
patent: 4290457 (1981-09-01), Campbell, Jr.
patent: 4477206 (1984-10-01), Papetti et al.
patent: 4573400 (1986-03-01), Foy
patent: 4640312 (1987-02-01), Patell et al.
patent: 5722795 (1998-03-01), Angel et al.
patent: 5846023 (1998-12-01), Angel et al.
Brinson Patrick
SeaMark Systems Limited
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