GB2156508A

GB2156508A - Storage container for hot media

Info

Publication number: GB2156508A
Application number: GB08506328A
Authority: GB
Inventors: Peter Brockerhoff; Der Decken Claus Benedict Von
Original assignee: Kernforschungsanlage Juelich GmbH
Current assignee: Forschungszentrum Juelich GmbH
Priority date: 1984-03-14
Filing date: 1985-03-12
Publication date: 1985-10-09
Also published as: JPS60215194A; GB8506328D0; FR2561353A1

Abstract

A storage container for hot liquid, e.g. water or oil, under super-atmospheric pressure is provided with thermal insulation on the inside of its structural walls 2,3,4, to protect them from overheating. This is a double-walled liner 7 containing thermal insulation 8 and pressurized with gas, e.g. air or nitrogen, whose pressure is matched to the pressure of the medium to be stored, e.g. 60 bar. Baffles 11 reduce convective gas flow in the liner 7. <IMAGE>

Description

SPECIFICATION Storage container for hot media The invention relates to a storage container for a hot medium which is under elevated pressure, i.e. under superatmospheric pressure. The storage container has internal insulation on inner side of a wall of the container.

Storage containers of this kind are known.

They consist, for example, of cast-iron blocks or of cast steel and are employed to store hot water or hot oil. For bracing the blocks, tension cables are provided, which extend in the direction of the axis and around the circumference of the storage container, which is of cylindrical form. For reasons of strength, these tension cables must not exceed predetermined upper temperature limits. Therefore, the storage containers are provided with internal insulation on the inner sides of the container walls. In addition to low thermal conductivity, the internal insulation must have material properties compatible with the medium to be stored. Also, such insulation must withstand the pressure of the media. In consequence, it is often the case that the internal insulation must overall be designed to meet conflicting requirements.

The invention seeks to provide a storage container for hot media under pressure, the wall of which storage container can be adequately protected against overheating even when there is high pressure in the storage vessel and when the medium to be stored is at high temperature.

To this end the present invention provides storage container for a hot medium under pressure with internal insulation on the inside of a wall of the container, characterised in that the internal insulation is a double-walied liner, the gap between its walls being filled with insulating material, and means being provided to pressurize the said gap with gas compressed to the pressure of the stored medium.

The internal insulation is provided in the gap between the walls of a double-walled liner and the gap is filled with a compressed gas, the pressure of which is adjusted to the pressure of the medium to be stored. The gas in the gap also penetrates into the cavities within the insulating material. Normally, the outer part of the double-walled liner will be in contact with the inner side of the storage container wall while the inner part of the liner encloses the storage chamber. Since the gas pressure in the gap between the walls is matched to the pressure in the storage chamber, the liner remains free from load.

The gas in the gap between the walls of the liner should have low thermal conductivity and thus give low heat transfer and hence low heat losses. Gases which may be used are, for example, air and nitrogen. In order also to prevent a convective gas flow in this gap and in the cavities within the insulation, convection barriers are preferably installed in the gap.

The invention will be further explained by the following description of an embodiment diagrammatically illustrated in the drawing.

The drawing illustrates in vertical section a storage container comprising a storage chamber 1. The container is assembled from castiron or cast-steel blocks 2 to form a vessel having a length (i.e. vertical height) L of 60 m and a diameter D of 7 m, with a base 3 and a cover 4. The blocks 2, the base 3 and the cover 4, which together form the container wall, are fitted together and braced by tension cables 5. Of these, the tension cables 5a preload the storage container wall in compression in an axial direction, while the tension cables 5b preload it in compression in a circumferential direction. The tension cables 5b are diagrammatically represented in the drawing by chain lines on the outside of the blocks 2.

On the inner side of the storage container wall is a double-walled sheet-steel liner 7 which encloses the storage chamber 1 in gastight manner. Situated in the gap between the walls of the double-walled liner 7 is an internal thermal insulation 8. In the illustrated embodiment this consists of ceramic material.

Suitable for the internal thermal insulation are ceramic fibrous materials or packing bodies, or glass fibre mats. Leading to the gap in the liner 7 is a compressed-gas duct 9 which communicates with a pressure regulator 10 and introduces compressed gas into this gap.

Disposed in the gap are convection barriers 11 which prevent convective flow of the gas within the gap and resultant heat loss from the storage chamber. The medium to be stored flows into and out of the storage chamber 1 of the storage chamber by way of a closable duct 1 2.

Gases with poor heat conduction, suitable for use in the gap between the walls of the liner 7 are, for example, air and nitrogen. In the illustrated embodiment, air is used.

The storage container was filled with water under a pressure of 60 bar and at a temperature of 280to. The gas in the gap of the liner was also set to the water pressure of 60 bar.

If there is a change in the pressure in the storage chamber 1 the pressure regulator 10 effects a corresponding change in the gas pressure in the gap between the walls of the liner 7.

When oil is stored in the storage container under a pressure of 60 bar and a temperature of 450to, then even at this temperature in the storage chamber 1 the temperature in the wall of the container is kept below 1 30 C.

In the embodiment shown and described the walls of the storage container are formed from cast iron or cast steel. In place of a cast iron storage container, or a container made of steel castings, storage containers of other materials may be substituted. For example a storage container could be made of concrete, or prestressed concrete, and equipped with a liner in accordance with this invention.

Claims

1. Storage container for a hot medium under pressure with internal insulation on the inside of a wall of the container, characterised in that the internal insulation is a doublewalled liner, the gap between its walls being filled with insulating material, and means being provided to pressurize the said gap with gas compressed to the pressure of the stored medium.

2. Storage container according to claim 1 wherein the said gap between the walls of the liner contains barriers to block convective movement of the gas therein.

3. A storage container for a hot medium under super-atmospheric pressure, substantially as herein described with reference to the accompanying drawing.