THERMALLY INSULATED ENCLOSURE CONTAINING EQUIPMENT INTENDED TO OPERATE AT A TEMPERATURE BELOW 0°C

Abstract

Insulated enclosure having at least one surface that is planar, containing at least one piece of equipment intended to operate at a temperature below 0 C., the interior space of the enclosure being intended to be at a pressure below atmospheric pressure and being filled with thermal insulation, and the thermal insulation being made up of a multitude of spherical beads made of thermally insulating material.

Claims

1. A thermally insulated enclosure having an interior space, the thermally insulated enclosure comprising: at least one outer surface that is planar; at least one piece of equipment (C, SR) intended to operate at a temperature below 0 C. disposed entirely within the interior space of the thermally insulated enclosure; wherein the interior space of the enclosure is configured to operate at a pressure below atmospheric pressure and be at least partially filled with thermal insulation, wherein the thermal insulation comprises, in respect of at least three-quarters of a volume of the interior space, a multitude of spherical beads made of thermally insulating material and which are hollow, wherein the spherical beads have a diameter of at most 1 mm and have a crush strength such that the volume of an entity formed by the multitude of spherical beads would reduce by at most 10% when the entity made up of the multitude of beads are subjected to a pressure of 0.1 MPa.

2. The thermally insulated enclosure according to claim 1, of which the walls are not thick enough to withstand the vacuum if the insulator had a crush strength such that its volume would reduce by more than 10% when the enclosure was evacuated to a pressure below 10.sup.1 mbara.

3. The thermally insulated enclosure according to claim 1, of parallelepipedal shape.

4. The thermally insulated enclosure according to claim 1, in which the spherical beads are made of glass.

5. The thermally insulated enclosure according to claim 1, having a minimum volume of 12 m.sup.3.

6. The thermally insulated enclosure according to claim 1, wherein the enclosure comprises a container that is a parallelepipedal metal box of standardized dimensions designed for transporting goods, equipped at least at one corner with a grab component allowing the enclosure to be lashed down and transshipped.

7. The thermally insulated enclosure according to claim 1, wherein the equipment is selected from the group consisting of at least one column configured to perform an exchange of heat and/or of material, at least one heat exchanger, at least one storage facility, at least one phase separator, and combinations thereof.

8. The thermally insulated enclosure according to claim 7, wherein the equipment is a column (C) or a heat exchanger (SR), the equipment being of parallelepipedal shape.

9. A method for filling the thermally insulated enclosure according to claim 1, the method comprising the steps of: placing at least one item of equipment inside the enclosure; filling the enclosure with the multitude of spherical beads; closing the enclosure; and at least partially evacuating the interior space inside the enclosure.

10. The method according to claim 9, wherein the enclosure is filled with the spherical beads through an opening formed by removing a sheet metal panel that forms part of a wall of the enclosure or that constitutes a wall of the enclosure.

11. A method of separation at a temperature below 0 C. by distillation and/or scrubbing, using the thermally insulated enclosure according to claim 1, wherein the interior space is filled with insulation and is evacuated to a pressure below atmospheric pressure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Further features and advantages of the invention will become apparent from the to description hereinafter of embodiments, which are given by way of illustration but without any limitation, the description being given in relation with the following attached FIGURE:

[0039] The FIGURE illustrates an air separation unit employing cryogenic distillation, comprising several insulated enclosures.

DETAILED DESCRIPTION OF THE INVENTION

[0040] A first insulated enclosure CB1 of parallelepipedal shape contains an air distillation column C, which in this instance is cylindrical but could have other geometries. The enclosure CB1 has a volume of at least 12 m.sup.3 and also contains a subcooler SR and pipes D3 to facilitate the drawing of the vacuum. The space around the equipment of the column is at least three-quarters filled, and preferably completely filled, with a multitude of spherical beads made from a thermally insulating material, and which are possibly hollow, having a crush strength preferably such that their volume would reduce by at most 10%, or even 5%, preferably by at most 1%, if the enclosure were evacuated to a pressure of 0.1 MPa.

[0041] The first enclosure CB1 is a parallelepipedal metal box of standardized dimensions designed for transporting goods, equipped at least at one corner with a grab component allowing it to be lashed down and transshipped.

[0042] The first enclosure CB1 may contain a main heat exchanger for cooling the air intended for the column and a distributor D3 which facilitate the drawing of the vacuum.

[0043] A second insulated enclosure CB2 contains a condenser R and distributors D1, D2 which facilitate the drawing of the vacuum.

[0044] A third insulated enclosure CB3 contains filters F which filter a liquid coming from the column C heading towards the pump P and a distributor D4 which facilitate the drawing of the vacuum.

[0045] The unit may comprise another insulated enclosure containing only the main heat exchanger, the insulation being in the form of beads.

[0046] The air distillation column C intended to operate at a pressure higher than atmospheric pressure is placed in the parallelepipedal enclosure CB1, for example a container of standardized dimensions. The distillation column C is attached to pipework for supplying it with air, for transferring potential reflux liquids and for transporting the products of the distillation. The enclosure CB1 is arranged with a large opening on one wall. One wall the may even be completely open. The enclosure is filled with beads until it is completely full, and the enclosure is agitated to compact the beads closely together. The beads used may for example be K1 glass microspheres made by 3M, having a density of 0.125 g/cm.sup.3. The wall is closed again for example by welding the wall or part of the wall in place, and the enclosure is evacuated down to a pressure of below 1 bara, typically a pressure of below 10.sup.4 mbara, or even of below 10.sup.3 mbara.

[0047] It is possible for the enclosure CB1 to contain thermal insulators other than the beads. For example, instrumentation or supports situated inside the enclosure may be insulated using Durostone Epoxy EPM203 or an item of equipment in the enclosure may be covered with a layer of insulation, the thermal insulation used having compression properties at least equivalent to those of the beads. Nevertheless, the beads will themselves alone constitute at least three-quarters of the insulation in terms of volume.

[0048] In the example, the enclosure has an outer shell containing equipment which is for example a column. It is also possible for the equipment to consist of a parallelepipedal box itself containing a column or a heat exchanger. In that case, the space between the parallelepipedal box and the outer shell is filled with a multitude of spherical beads made from a thermally insulating material, and which are possibly hollow, having a crush strength preferably such that their volume would reduce by at most 10%, or even 5%, preferably by at most 1%, if the entity formed by the multitude of beads were subjected to a pressure of 0.1 MPa.

[0049] The space between the parallelepipedal box and the column does not contain insulation and is not evacuated. The space between the parallelepipedal box and the outer shell is filled by removing a sheet metal panel that forms part of a wall of the enclosure or that constitutes a wall of the enclosure, for example the roof. Otherwise, a lid may be used, as mentioned hereinabove.

[0050] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

[0051] The singular forms a, an and the include plural referents, unless the context clearly dictates otherwise.

[0052] Comprising in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing (i.e., anything else may be additionally included and remain within the scope of comprising). Comprising as used herein may be replaced by the more limited transitional terms consisting essentially of and consisting of unless otherwise indicated herein.

[0053] Providing in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

[0054] Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0055] Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.