CA2255500A1 - Dual containment condensation assembly - Google Patents

Description

TEM File No. 150.5 TITLE: DUAL CONTAINMENT CONDENSATION ASSEMBLY
FIELD OF THE INVENTION
The present invention relates to condensation units for condensing fluids and containers for storing liquid substances, for use in the petroleum, industrial, agricultural and petro-chemical industries.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:
Figure 1 is an elevation view of a condensation and containment assembly according to a preferred embodiment of the present invention;
Figure 2 is a plan view of the assembly of fig. l;
Figure 3 shows, in elevation, an alternate embodiment of the assembly of the present invention; and, Figure 4 is a plan view of the assembly of fig.3.
A dual containment condensation assembly 10 according to the present invention generally comprises a condensation component or unit 20, mounted atop a containment assembly, or storage tank 50, for storing a liquid substance exiting the condensation unit 20. The storage tank 50 may be of the type shown and described in applicant's co-pending Canadian Patent Application no. 2,196,941 for a "Dual Containment Assembly", and is incorporated herein by reference. The condensation unit 20 receives a fluid and is configured to urge the fluid to separate into gas and liquid components, the liquid component being deposited by gravity and stored in the cylindrically shaped tank SO for future disposal or treatment as required. For illustrative purposes, the fluid in this instance will be a vaporized liquid which may contain some condensed liquids encountered in the petroleum industry.
Refernng specifically to figures 1 and 2, the fluid enters the cylindrically shaped condensation unit 20 of the assembly 10 through an inlet 22 and expands in an annular space 24 between the outer and inner side walls 26 & 28, respectively, of the condensation unit 20. Since vapour tends to rise, the inlet 22 is located at a lower end of the annular space 24. The entering fluid is directed counterclockwise through the annular space 24.
The entering fluid is prevented from traveling directly clockwise to a liquid outlet 23 near the floor 32 of the condensation unit by a "full" divider bale 30 extending between the inner and outer walls 28, 26 and between the condensation unit's roof 31 and floor 32.
The roof 31 is non-porous to prevent upward escape of the fluid therethrough from the annular space 24. A series of partial divider bai~les 34, affixed to the inside of the roof 31 and spaced circumferentially about the annular space 24, trap the fluid's hot vapours and increase their retention time within the annular space by deflecting the vapours downwardly as they travel counterclockwise about the annular space 24.
As the vapours travel about the annular space they condense into liquid form and drop through the floor 32 into the dual-containment storage tank 50 below where additional retention time occurs. Most of the floor 32 is formed of a grid support and support plate assembly 33 laid over with a "mist pad" 36, namely a type of fine grating or intertwined strands of fine metallic or other suitable materials, which allows the condensed

-2-liquid to travel therethrough into the tank 50. A portion of the floor 32 at the inlet and outlet ends is formed of solid plates 37 which are sloped downwardly away from the full divider baffle 30 to direct any liquid collected thereon toward the adjoining mist pad 36.
A series of vertically disposed plate-like cooling fins 38 extend outwardly from the condensation unit's outer side wall 26 to increase heat transfer between the annular space 24 and the ambient. In the instant example, the fins serve to cool the condensation unit to promote liquid condensation.
In the preferred embodiment, the storage tank 50 is formed of an inner or primary storage tank 54 which is surrounded by an outer or secondary containment tank 51. The primary tank 54 has a vertically disposed, planar, plate-like weir 52 affixed to the bottom 56 and sides 58 of the primary tank 54, which weir 52 is about the same height as the primary storage tank 54. In the embodiment shown, the weir 52 divides the tank 54 in half, and is in line with full divider baffle 30 (as viewed in fig.2). The exact location of the weir will depend on several factors, including the type of fluid to be treated, prevailing climactic conditions, and the like, and may be aided through actual field experimentation.
The purpose of the weir 52 is to provide a partial 2-phase separation of the condensed liquids. For example, in the case of glycol/water vapour, the glycol condenses at a lower temperature and will therefore accumulate in the first part of the primary storage tank 54 divided by the weir indicated by "phase 1 ", and the water vapour will condense later and be mainly accumulated in the second part indicated by "phase 2".
The primary vapour outlet 23 from the annular space 24 of the condensation unit 20 is located near the floor 32 and extends through the inner side or shell wall 28 into an inside space or chamber 40. A "final" vent outlet connection 42 for the complete condensation and storage tank assembly 10 is located in the middle of the roof 31, and is

-3-fitted with another mist pad 43 to extract any additional suspended liquids in the fluid in the chamber 40. The vent outlet 42 extents partially into the chamber 40 of the condensation unit to provide additional retention time for vapours produced from the liquid collected in the primary storage tank 54, as well as any remaining vaporized product carried over from the annular space 24 of the condensation unit into the chamber 40.
The condensed liquid is emptied from the primary storage tank 54 through a pumpout connection 60 near the bottom 56 of the tank.
The dual-containment storage tank assembly 10 may or may not require heating and/or insulation 62 to prevent the stored liquid from freezing, depending on the local climate where installed. The tank assembly should be elevated above ground level , as shown.
To protect the tank assembly from overflowing, the unit is fitted with an external gaugeboard assembly 64 and possibly liquid level shutdown switches. Any accidental overflow into the secondary containment space 66 is detected through the use of an externally mounted sight glass 68.
Figures 3 and 4 show another embodiment of the invention which has a different, namely elevated, inlet 122 into the condensation unit, an outlet 123 which leads directly to the vent 42, and omits a weir in the primary storage tank 54. The same reference numerals are used for the same or substantially similar components.
The above description is intended in an illustrative rather than a restrictive sense and variations to the specific configurations described may be apparent to skilled persons in adapting the present invention to specific applications. Such variations are intended to form part of the present invention insofar as they are within the spirit and scope of the claims below.

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Claims