Cold box and assembly method

Abstract

A cold box and a method of assembling the same for the purpose of accommodating an assembly of pipes and equipment for a fluid under vacuum, the cold box comprising a fluid-tight shell (2) defining a cylindrical portion extending in the longitudinal direction (A), and the two longitudinal ends of the fluid-tight shell (2) being closed by end walls (3) respectively. In the cold box and the method, the cylindrical portion (2) is longitudinally divided into two parts including a lower first part (4) forming a trough that is open at its upper part, and a second part (5) forming a cover that is fixed to and closes the upper end of the first part (4).

Description

Technical Field

[0001] The present invention relates to cold boxes and related assembly methods.

[0002] More specifically, the present invention is a cold box intended to accommodate a series of fluid pipes and equipment under vacuum, including a fluid-tight enclosure defining a longitudinally extending cylindrical portion, each of the two longitudinal ends of the fluid-tight enclosure being closed by an end wall.

[0003] The present invention relates to cold boxes used in refrigeration equipment, particularly cryogenic refrigeration equipment, particularly fluid liquefaction and / or cooling equipment.

Background Art

[0004] The combination of an increasing liquefaction capacity and a reduction in the size of the cold box has led to a gradually increasing filling rate of the vacuum housing (the number of equipment and pipes inside the housing). Such filling hinders easy access by manufacturing workers inside. This further poses significant safety issues, such as the isolation of workers, confined spaces, and the risk of ignition of thermal insulation materials within confined spaces.

[0005] The shortage of available space inside the cold box has an adverse effect on the productivity of manufacturing and assembly. The number of personnel who can work simultaneously is extremely limited, thereby increasing the manufacturing time and the risk of accidents.

[0006] In particular, installing large equipment (exchanger batteries or large pipes) inside the housing is difficult. The reduced accessibility also affects the manufacturing quality, mainly the welding of cryogenic lines and multi-layer insulation (MLI).

Summary of the Invention

Problems to be Solved by the Invention

[0007] One object of the present invention is to overcome all or some of the aforementioned drawbacks of the prior art.

Means for Solving the Problem

[0008] For this purpose, the cold box according to the present invention, which otherwise corresponds to the general definition given in the above premise part, is essentially characterized in that the cylindrical part is longitudinally cut into two parts including a first part at the lower part forming a trough having an open upper part and a second part fastened to the upper part of the first part at the lower part and forming a cover for closing the first part at the lower part.

[0009] Furthermore, embodiments of the present invention may include one or more of the following features. - The cylindrical part is longitudinally cut at an upper part, that is, above the midpoint of the height of the cylindrical part measured in the transverse direction in the longitudinal direction. - The cylindrical part has a circular base. - In a plane perpendicular to the longitudinal direction, the opening angle of the first part at the lower part of the cylindrical part measured with respect to the center of the cylindrical part is 80° to 180°, preferably 90° to 150°. - The cold box includes a series of devices such as one or more heat exchangers, pipes, taps, piping fixtures, pressurizing devices, valves, rotating machines, etc. attached to a support chassis, and the support chassis is attached to the first part at the lower part of the cylindrical part. - The support chassis is fastened to at least one of one or more supports, particularly a series of rails, a series of intermittent fastening points, located at the inner bottom of the first part at the lower part of the cylindrical part. - The support chassis is firmly connected to the cover, and this assembly is fastened to the first part at the lower part of the cylindrical part. - The support chassis has a lattice structure. - The support chassis is attached to the first part at the lower part of the cylindrical part perpendicular to the longitudinal direction A. - The cold box includes a series of circuits, and / or valves, and / or rotating machines, and / or electrical bushings attached to the cover and passing through the cover via a fluid-tight passage. - A series of circuits assembled through the cover are connected to a series of devices of the support chassis. - The inner surface of the cover is firmly connected to a series of structural and mechanical joining elements, such as shafts, which are mechanically connected to the support chassis of a series of devices and / or the first part at the lower part of the cylindrical part. - When the cold box is in the use position, the longitudinal direction is horizontal or vertical.

[0010] The present invention relates to a method of assembling a cold box composed of a fluid-tight enclosure defining a longitudinally extending cylindrical part and two end walls provided to close the longitudinal ends of the cylindrical part. The cylindrical part is longitudinally cut into two parts including a first part at the lower part forming a trough with an open upper part and a second part fastened to the upper part of the first part at the lower part and forming a cover for the purpose of closing the first part at the lower part. The method includes the steps of attaching a series of fluid devices, such as one or more heat exchangers, pipes, taps, plumbing fixtures, pressurizing devices, valves, turbines, rotating machines, etc., to the first part (4) at the lower part of the cylindrical part, attaching a series of circuits and optionally devices to the cover through a fluid-tight passage, and sealing the cylindrical part with the cover and the two end walls.

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

[0012] Further specific features and advantages will become apparent by reading the following description provided with reference to the drawings.

[0013] The present invention will be better understood by reading the following description provided with reference to the accompanying drawings by way of example only.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0015] The illustrated cold box 1 is intended to house a series of fluid devices and pipes that operate particularly at extremely low temperatures, i.e., temperatures below -100°C.

[0016] The cold box 1 preferably includes a fluid-tight enclosure 2 (e.g., made of metal) defining a cylindrical portion extending in the longitudinal direction A and having a circular base, and each of the two longitudinal ends is closed by an end wall 3 (e.g., a convex wall). This cylindrical shape with a circular base is particularly suitable for vacuum storage.

[0017] The illustrated cold box 1 is a horizontal cold box, i.e., when the cold box is in the use position, the longitudinal direction A is horizontal. Of course, the present invention can also be applied to a vertical cold box.

[0018] According to an advantageous feature, the cylindrical portion 2 (or at least a part thereof) is longitudinally cut into two parts including a first lower part 4 forming a trough with an open upper part and a second part forming a cover 5 fastened to the upper part of the first lower part 4 and sealing the first lower part 4. These different parts can be made, for example, by sheet metal working.

[0019] The cylindrical part 2 can be cut longitudinally above the middle, preferably at the upper part, i.e., above the midpoint of the height of the cylindrical part measured in the transverse direction in the longitudinal direction A.

[0020] For example, as schematically shown in [Figure 6], in a plane perpendicular to the longitudinal direction A, the opening angle B of the lower part of the cylindrical part measured with respect to the center of the cylindrical part is preferably 80° to 180°, more preferably 90° to 150°. Thereby, it becomes possible to firmly connect the devices to the chassis 6 and the cover 5 on this trough, and good accessibility during integration is provided. This structure also provides a certain degree of flexibility for the final welding operation.

[0021] Therefore, the proposed solution provides the tubular part with parts or two "half shells". The two parts are welded longitudinally, especially after the internal element is attached to the internal volume (for example, final welding).

[0022] This means that the two parts are welded after the cold box is assembled. Therefore, instead of inserting the internal element (such as devices) longitudinally into a closed tube as in the prior art, it can be integrated onto the support chassis 6 that can be firmly connected to the cover 5, for example, before assembling the two parts.

[0023] The devices can be attached to the support chassis 6 (see [Figure 2]). The support chassis 6 can have a lattice structure.

[0024] Similarly, the devices and / or pipes can be attached to the upper part 5 (cover) (see [Figure 3]). For example, a series of circuits are attached to the cover 3 and pass through the cover 3 via a fluid-tight passage. Thereby, the position of the interface is optimized, ensuring that most of the interface is located in this upper half shell, i.e., the cover 3.

[0025] These two sub-components can be assembled (see [Figure 4]). In this case, a series of circuits assembled via the cover 5 can be connected to a series of devices 7 of the support chassis 6.

[0026] For this purpose, the inner surface of the cover 5 can be firmly connected to a series of structural or mechanical connection members 9 such as shafts, columns, rods, etc. that are distributed longitudinally and protrude so as to be mechanically connected to at least the support chassis 6.

[0027] The assembly including the cover 5 and the support chassis 6 can then be fastened to one or more supports 8, preferably temporary supports, located at the bottom inside the lower part 4 of the cylindrical part. This means that these supports 8 can be provided for the operator.

[0028] For example, the assembly including the support chassis 6 and the cover 5 is vertically inserted into the lower part 4 and placed on the supports at the bottom of the lower part 4. The internal chassis has one or more stationary / sliding points with the housing. These stationary and sliding points can be selected to limit the thermal stress to the devices 7 of the support chassis 6 and / or the cold box 1.

[0029] Note that the bottom 3 (end wall) may or may not be provided in advance on the cylindrical lower part 4.

[0030] This structure, especially the chassis 6, greatly strengthens the upper part 5 for subsequent operations.

[0031] This structure and its use facilitate the assembly of the devices within the housing.

[0032] This solution reduces the manufacturing time and improves the safety of the manufacturing operations. The work of integrating the devices and the circuits can be carried out in parallel for different parts.

[0033] The chassis 6 can simplify the installation of heavy equipment. Since the chassis can support most of the internal equipment, tools for incorporating the equipment into the housing are no longer necessary. At the start of the work, the chassis 6 can be separated from the lower part 4 and the upper part 5 of the housing.

[0034] This structure enables assembly work to be carried out in a work area with good accessibility and good lighting, an open environment, which is very useful for integration and also inspection.

[0035] Mechanical reinforcements can be provided around the stationary points and around the handling points of the upper part 5.

[0036] Safety is greatly improved, and work done inside the closed housing is strictly minimized. More workers can be used, which, combined with better accessibility, helps to reduce costs and lead times. The pipeline can be integrated in longer sections, reducing the number of welds and the rework of insulation materials. The final quality is improved, the risk of leakage is reduced, and the thermal efficiency is improved. This structure greatly simplifies the installation of pipe supports.

[0037] This detailed description refers to one or more embodiments, but this does not mean that the features apply only to a single embodiment. Simple features of different embodiments can be combined and / or exchanged to provide other embodiments in relation to the claims.

Claims

**Claim 1** A cold box for the purpose of accommodating a series of fluid pipes and equipment under vacuum, comprising a fluid-tight enclosure (2) defining a cylindrical portion extending in the longitudinal direction (A), each of the two longitudinal ends of the fluid-tight enclosure (2) being closed by an end wall (3), the cylindrical portion (2) being longitudinally cut into two parts including a lower first part (4) forming a trough having an open upper part and a second part forming a cover (5) fastened to the upper part of the first part (4) and closing the first part (4). In the cold box, the cylindrical portion (2) is longitudinally cut at the upper part, i.e., above the midpoint of the height of the cylindrical portion measured transversely in the longitudinal direction (A), and in a plane perpendicular to the longitudinal direction (A), the opening angle (B) of the lower first part (4) of the cylindrical portion measured with respect to the center of the cylindrical portion is 90° to 150°. A cold box characterized by this. **Claim 2** The cold box according to claim 1, characterized in that the cylindrical portion (2) has a circular base. **Claim 3** Including a series of equipment (7) such as one or more heat exchangers, pipes, taps, piping fixtures, pressurizing equipment, valves, rotating machinery, etc. attached to a support chassis (6), the support chassis (6) being attached to the lower first part (4) of the cylindrical portion. The cold box according to claim 1 or 2, characterized by this. **Claim 4** The cold box according to claim 3, characterized in that the support chassis (6) is fastened to at least one of one or more supports, particularly a series of rails, a series of intermittent fastening points, located at the inner bottom of the lower first part (4) of the cylindrical portion. **Claim 5** The cold box according to any one of claims 4, characterized in that the support chassis (6) is firmly connected to the cover (5), and this assembly is fastened to the lower first part (4) of the cylindrical portion. **Claim 6** The cold box according to any one of claims 3 - 5, characterized in that the support chassis (6) has a lattice structure. **Claim 7** The cold box according to any one of claims 3 to 6, characterized in that the support chassis (6) is attached to a first part (4) at the lower part of the cylindrical part perpendicular to the longitudinal direction (A).

8. The cold box according to any one of claims 1 to 7, characterized in that it includes a series of circuits and / or electrical bushings that are attached to the cover (5) and pass through the cover (5) via a fluid-tight passage.

9. The cold box according to claim 8, in combination with any one of claims 3 to 7, characterized in that the series of circuits assembled through the cover (5) are connected to the series of devices (7) of the support chassis (6).

10. The cold box according to claim 8 or 9, characterized in that the inner surface of the cover (5) is firmly connected to a series of structural (9) mechanical joining elements (9) such as a shaft that is mechanically connected to the support chassis (6) of the series of devices (7) and / or the first part (4) at the lower part of the cylindrical part (2).

11. The cold box according to any one of claims 1 to 10, characterized in that when the cold box is in the use position, the longitudinal direction (A) is horizontal or vertical.

12. A method of assembling a cold box (1) composed of a fluid-tight enclosure (2) defining a cylindrical portion extending in the longitudinal direction (A) and two end walls (3) provided for closing the longitudinal ends of the cylindrical portion, wherein the cylindrical portion (2) is cut into two parts including a lower first part (4) forming a trough having an open upper part and a second part forming a cover (5) fastened to the upper part of the lower first part (4) and intended to close the lower first part (4), the method comprising the steps of attaching a series of fluid devices (7) such as one or more heat exchangers, pipes, taps, plumbing fixtures, pressurizing devices, valves, turbines, rotating machinery, etc. to the lower first part (4) of the cylindrical portion, attaching a series of circuits and optionally devices to the cover (5) through fluid-tight passages, and sealing the cylindrical portion (2) with the cover (5) and the two end walls (3), wherein the cylindrical portion (2) is cut longitudinally at the upper part, i.e., above the midpoint of the height of the cylindrical portion measured transversely in the longitudinal direction (A), and in a plane perpendicular to the longitudinal direction (A), the opening angle (B) of the lower first part (4) of the cylindrical portion measured with respect to the center of the cylindrical portion is from 90° to 150°.

13. During the step of attaching the series of fluid devices (7) to the lower first part (4) of the cylindrical portion (2), the series of fluid devices (7) is attached to a support chassis (6) attached to the lower part (4) of the cylindrical portion, according to the method of claim 12.

14. The support chassis (6) is vertically inserted into the lower first part (4) of the cylindrical portion, according to the method of claim 13.

Images