Cold box and method of assembly

Abstract

Cold box intended to house, under vacuum, a collection of pipes and equipment for fluid, and method for assembling same, the cold box comprising a fluid-tight shell (2) delimiting a cylindrical portion extending in a longitudinal direction (A) and the two longitudinal ends of which are each closed by an end wall (3), characterized in that the cylindrical portion (2) is split longitudinally into two parts comprising: a lower first part (4) forming a trough that is open at its top, and a cover-forming second part (5) fixed to the upper end of the first part (4) and closing same.

Description

Cold box and assembly process.

[0001] The invention relates to a cold box and its assembly method.

[0002] The invention relates more particularly to a cold box intended to house under vacuum a set of pipes and fluidic equipment, the cold box comprising a sealed envelope delimiting a cylindrical portion extending in a longitudinal direction and the two longitudinal ends of which are each closed by an end wall.

[0003] The invention relates to cold boxes used in refrigeration installations, in particular cryogenic ones, in particular for installations for cooling and / or liquefying fluids.

[0004] The increase in liquefaction capacities combined with a reduction in the size of cold boxes results in an increasingly high filling rate (number of equipment and piping in the enclosure) of vacuum enclosures. This filling prevents manufacturing operators from easily accessing the interior. This leads to increasingly significant safety problems: isolated worker, confined space, risk of ignition of the insulation in a restricted space, etc.

[0005] The lack of available space in the cold box is detrimental to manufacturing and assembly productivity. The number of simultaneous workers is severely limited, which leads to longer manufacturing times and increases the risk of accidents.

[0006] It is particularly difficult to insert large equipment (such as heat exchanger batteries or large pipes) into the enclosure. Reduced accessibility also impacts manufacturing quality, mainly welding and insulation using multi-layer "MLI" insulation of cryogenic lines.

[0007] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0008] To this end, the cold box according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the cylindrical portion is cut longitudinally into two parts comprising: a first lower part forming a chute open in its upper part and a second part forming a cover fixed at the level of the upper end of the first lower part and closing the latter.

[0009] Furthermore, embodiments of the invention may comprise one or more of the following features: the cylindrical portion is cut longitudinally in its upper part, i.e. above half the height of the cylindrical portion measured transversely to the longitudinal direction, the cylindrical portion has a circular base, in a plane perpendicular to the longitudinal direction, the opening angle of the first lower part of the cylindrical portion measured relative to the center of the cylindrical portion is between 80 and 180 degrees and preferably between 90 and 150 degrees, the cold box comprises a set of equipment such as one or more heat exchangers, piping, valves, piping components, pressure equipment, valve(s), rotating machine(s) mounted on a support frame, said support frame being mounted in the first lower part of the cylindrical portion,the support frame is fixed on one or more supports located on the bottom in the first lower part of the cylindrical portion, in particular at least one of: a set of rails, a set of punctual fixing points, the support frame is made integral with the cover and this assembly is fixed to the first lower part of the cylindrical portion, the support frame has a lattice structure, the support frame is mounted in the first lower part of the cylindrical portion perpendicular to the longitudinal direction A, the cold box comprises a set of circuits and / or valve(s) and / or rotating machine(s) and / or electrical feedthrough(s) mounted on the cover and passing through the cover via sealed passages, the set of circuits mounted through the cover is connected to the set of equipment of the support frame, an inner face of the cover is integral with a set of structural mechanical connection element(s),such as axes, mechanically connected to the equipment assembly and / or to the support frame of the first lower part of the cylindrical portion, in the position of use of the cold box, the longitudinal direction is horizontal or vertical.,

[0010] The invention also relates to a method for mounting a cold box composed of a sealed casing delimiting a cylindrical portion extending in a longitudinal direction and two end walls provided to close the longitudinal ends of the cylindrical portion, the cylindrical portion being cut longitudinally into two parts comprising: a first lower part forming a chute open in its upper part and a second part forming a cover intended to be fixed at the upper end of the first lower part and closing the latter, the method comprising a step of mounting a set of fluidic equipment such as one or more heat exchangers, piping(s), valves, piping member(s), pressure equipment(s), valve(s), turbine(s), rotating machine(s) in the first lower part (4) of the cylindrical portion,a step of mounting a circuit assembly and possibly equipment(s) on the cover through sealed passages, a step of sealing the cylindrical portion with the cover and two end walls.,

[0011] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0012] Other features and advantages will appear on reading the description below, made with reference to the figures in which: Brief description of the figures

[0013] The invention will be better understood on reading the following description, given solely by way of example and with reference to the appended drawings in which:

[0014] is a schematic perspective view of an example of a cold box structure in a disassembled state,

[0015] is a schematic perspective view of an example of a first part of the cold box according to the invention during assembly,

[0016] is a schematic perspective view of an example of a second part of the cold box according to the invention during assembly,

[0017] is a schematic perspective view of the assembly of the first and second parts during assembly,

[0018] is a schematic perspective view of the assembly of the first and second parts assembled in a third part of the cold box being assembled,

[0019] is a schematic and partial view of a section of the lower part of the cylindrical portion of the cold box. Detailed description

[0020] The cold box 1 illustrated is intended to house under vacuum a set of pipes and fluidic equipment, particularly cryogenic, i.e. operating at a temperature below – 100°C.

[0021] The cold box 1 comprises a sealed casing 2 (for example made of metallic material) delimiting a cylindrical portion extending in a longitudinal direction A, preferably with a circular base, and the two longitudinal ends of which are each closed by an end wall 3 (for example convex walls). This cylindrical shape with a circular base is particularly suitable for vacuum holding.

[0022] This cold box 1 illustrated is of the horizontal type, that is to say that, in the position of use of the cold box, the longitudinal direction A is horizontal. Of course, the invention can also be applied to a cold box of the vertical type.

[0023] According to an advantageous feature, the cylindrical portion 2 (or at least part of it) is cut longitudinally into two parts comprising: a first lower part 4 forming a chute open at the top and a second part forming a cover 5 fixed at the level of the upper end of the lower part 4 and closing the latter in a sealed manner. These different parts can for example be obtained by boilermaking.

[0024] The cylindrical portion 2 can be cut longitudinally at mid-height and preferably in its upper part, that is to say above half the height of the cylindrical portion measured transversely to the longitudinal direction A.

[0025] For example, and as shown diagrammatically in the, in a plane perpendicular to the longitudinal direction A, the opening angle B of the lower part of the cylindrical portion measured relative to the center of the cylindrical portion is preferably between 80 and 180 degrees and even more preferably between 90 and 150 degrees. This makes it possible to easily position the equipment secured to the chassis 6 and the cover 5 on this chute, while providing good accessibility during integration. This structure also allows a certain flexibility for the final welding operations.

[0026] The proposed solution thus provides for the tubular portion in parts or two "half-shells". The two parts are welded, in particular longitudinally when the internal elements have been mounted in the interior volume (final welding for example).

[0027] That is to say, the two parts are welded when the cold box is assembled. The integration of the internal elements (equipment, etc.) can thus be carried out before assembly of the two parts, for example on a support frame 6 which can be made integral with the cover 5 instead of being inserted longitudinally into a closed tube as is the case in the prior art.

[0028] Equipment can be mounted on the support frame 6 (see). The support frame 6 can have a lattice structure.

[0029] Similarly, equipment and / or piping may be mounted on the upper part 5 (cover) (cf.). For example, a set of circuitry is mounted on the cover 3 and passes through the cover 3 via sealed passages. This makes it possible to optimize the position of the interfaces so that the majority of them are located on this cover 3 or “upper half-shell”.

[0030] These two sub-parts can be assembled (cf.). On this occasion the circuitry assembly mounted through the cover 5 can be connected to the equipment assembly 7 of the support chassis 6

[0031] For this purpose, the inner face of the cover 5 may be secured to a set of mechanical or structural connecting members 9, such as axes, posts, rods or other distributed longitudinally and which extend in projection to be mechanically connected at least to the support frame 6.

[0032] Then, the cover 5 and support frame 6 assembly can be fixed on one or more possible supports 8, preferably temporary, located on the bottom in the lower part 4 of the cylindrical portion. That is to say that these supports 8 can be provided for the operators.

[0033] For example, the support frame assembly 6 with the cover 5 is inserted vertically into the lower part 4 and is placed on supports in the bottom of the lower part 4. The internal frame has one or more fixed points / sliding points with the enclosure. These fixed and sliding points can be chosen to limit the thermal stresses on the support frame 6 and / or on the equipment 7 of the cold box 1.

[0034] Note that the lower cylindrical part 4 may or may not be provided beforehand with a base 3 (end wall).

[0035] This structure, and in particular the chassis 6, significantly reinforces the upper part 5 for the following operations.

[0036] This structure and its use allow for easy mounting of equipment in the enclosure.

[0037] The solution saves manufacturing time and ensures the safety of manufacturing operations. Equipment and circuit integration work can be carried out in parallel on the different parts.

[0038] The chassis 6 can simplify the installation of heavy equipment. Integration tools in the enclosure are no longer necessary because the chassis can carry the majority of internal equipment. At the start of operations, the chassis 6 can be independent of the lower 4 and upper 5 parts of the enclosure.

[0039] This structure allows assembly operations to be carried out in a workshop, in an open environment, with good accessibility and good lighting, very useful for integration, but also for inspection.

[0040] Mechanical reinforcements can be provided on the upper part 5 at the fixed points and at the handling points.

[0041] Safety is significantly improved, and the work to be carried out within the enclosed space is reduced to a strict minimum. The number of workers can easily be increased, which, combined with much better accessibility, reduces both costs and time. Pipe lines can be integrated in longer sections, reducing the number of welds and insulation repairs. The final quality is improved, with a reduced risk of leaks and improved thermal efficiency. The structure significantly simplifies the installation of pipe supports.

[0042] In this detailed description, although the description refers to one or more embodiments, this does not mean that the features apply only to a single embodiment. Single features of different embodiments may also be combined and / or interchanged to provide other embodiments within the scope of the claims.

Claims

Cold box intended to house under vacuum a set of pipes and fluidic equipment, the cold box comprising a sealed envelope (2) delimiting a cylindrical portion extending in a longitudinal direction (A) and whose two longitudinal ends are each closed by an end wall (3), the cylindrical portion (2) being cut longitudinally into two parts comprising: a first lower part (4) forming a chute open in its upper part and a second part forming a cover (5) fixed at the level of the upper end of the first part (4) and closing the latter, in which the cylindrical portion (2) is cut longitudinally in its upper part, that is to say above half the height of the cylindrical portion measured transversely to the longitudinal direction (A). Cold box according to claim 1, characterized in that the cylindrical portion (2) has a circular base. Cold box according to any one of claims 1 to 2, characterized in that, in a plane perpendicular to the longitudinal direction (A), the opening angle (B) of the first lower part (4) of the cylindrical portion measured with respect to the center of the cylindrical portion is between 80 and 180 degrees and preferably between 90 and 150 degrees. Cold box according to any one of claims 1 to 3, characterized in that it comprises a set of equipment (7) such as one or more heat exchangers, piping, valves, piping components, pressure equipment, valve(s), rotating machine(s) mounted on a support frame (6), said support frame (6) being mounted in the first lower part (4) of the cylindrical portion. Cold box according to claim 4, characterized in that the support chassis (6) is fixed on one or more supports located on the bottom in the first lower part (4) of the cylindrical portion, in particular at least one of: a set of rails, a set of point fixing points. Cold box according to any one of claims 5, characterized in that the support chassis (6) is made integral with the lid (5) and this assembly is fixed to the first lower part (4) of the cylindrical portion. Cold box according to any one of claims 4 to 6, characterized in that the support chassis (6) has a lattice structure. Cold box according to any one of claims 4 to 7, characterized in that the support chassis (6) is mounted in the first lower part (4) of the cylindrical portion perpendicular to the longitudinal direction A. Cold box according to any one of claims 1 to 8, characterized in that it comprises a set of circuits and / or valve(s) and / or rotating machine(s) and / or electrical passage(s) mounted on the cover (5) and passing through the cover (5) via sealed passages. cold box according to claim 9 combined with any one of claims 4 to 8, characterized in that the assembly of through-mounted circuits on the lid (5) is connected to the assembly of equipment (7) of the supporting chassis (6). Cold box according to claims 9 or 10, characterized in that an inner face of the lid (5) is integral with a set of structural element(s) (9) of mechanical connection (9), such as axes, mechanically connected to the set of equipment (7) and / or to the chassis (6) supporting the first lower part (4) of the cylindrical portion (2). Cold box according to any one of claims 1 to 11, characterized in that, in the position of use of the cold box, the longitudinal direction (A) is horizontal or vertical. Method of assembling a cold box (1) composed of a sealed casing (2) delimiting a cylindrical portion extending in a longitudinal direction (A) and two end walls (3) provided to close the longitudinal ends of the cylindrical portion, characterized in that the cylindrical portion (2) is cut longitudinally into two parts comprising: a first lower part (4) forming a chute open in its upper part and a second part forming a cover (5) intended to be fixed at the level of the upper end of the first lower part (4) and closing the latter, the method comprising a step of assembling a set of fluidic equipment (7) such as one or more heat exchangers, piping, valves, piping components, pressure equipment, valve(s), turbine(s), rotating machine(s) in the first lower part (4) of the cylindrical portion,a step of mounting a circuit assembly and possibly equipment(s) on the cover (5) through sealed passages, a step of sealing the cylindrical portion (2) with the cover (5) and two end walls (3). Method according to claim 13, characterized in that, during the step of mounting the assembly of fluidic equipment (7) in the first lower part (4) of the cylindrical portion (2), the assembly of fluidic equipment (7) is mounted on a support chassis (6) which is mounted in the lower part (4) of the cylindrical portion. Method according to claim 14, characterized in that the support chassis (6) is inserted vertically into the first lower part (4) of the cylindrical portion.

Images