U.S. patent application number 12/029563 was filed with the patent office on 2008-06-05 for cold box and cryogenic plant including a cold box.
This patent application is currently assigned to L'Air Liquide Societe Anonyme A'Directoire Et Conseil De Surveillance Pour L'Etude Et L'Exploita. Invention is credited to Denis Cote, Jean-Pierre Gourbier, Richard Pawulski.
Application Number | 20080127675 12/029563 |
Document ID | / |
Family ID | 35285612 |
Filed Date | 2008-06-05 |
United States Patent
Application |
20080127675 |
Kind Code |
A1 |
Cote; Denis ; et
al. |
June 5, 2008 |
Cold Box and Cryogenic Plant Including a Cold Box
Abstract
This disclosure discusses providing safer and more accessible
insulating cold boxes for cryogenic equipment. A cold box of the
current invention includes a housing partially extending out of the
cold box jacket wherein equipment that may need to be accessed can
be located. The housing includes a breakaway barrier between the
main cold box and the external housing to allow overpressures to be
relieved into the cold box. Cold boxes may contain cryogenic
columns, sections of cryogenic columns, distillation columns,
mixing columns, storage vessels, pressure vessels, heat exchangers,
and combinations thereof. The housing may contain auxiliary
elements such as rotating equipment, pumps, turboexpanders,
instrument devices, valves, and piping. Placing auxiliary elements
in a housing outside the main cold box allows for safer access to
cryogenic equipment.
Inventors: |
Cote; Denis; (Sugar Land,
TX) ; Gourbier; Jean-Pierre; (Le Plessis Trevise,
FR) ; Pawulski; Richard; (Houston, TX) |
Correspondence
Address: |
AIR LIQUIDE;Intellectual Property
2700 POST OAK BOULEVARD, SUITE 1800
HOUSTON
TX
77056
US
|
Assignee: |
L'Air Liquide Societe Anonyme
A'Directoire Et Conseil De Surveillance Pour L'Etude Et
L'Exploita
Paris
FR
|
Family ID: |
35285612 |
Appl. No.: |
12/029563 |
Filed: |
February 12, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10972828 |
Oct 25, 2004 |
7340921 |
|
|
12029563 |
|
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Current U.S.
Class: |
62/643 |
Current CPC
Class: |
F17C 13/001 20130101;
F25J 3/04987 20130101; F25J 3/04878 20130101; F17C 2201/032
20130101; Y10S 62/907 20130101; F17C 2227/0135 20130101; F17C
2223/0161 20130101; F25J 3/0489 20130101; F17C 2201/054 20130101;
F17C 2223/033 20130101; F17C 2221/011 20130101; F17C 2205/0111
20130101; F17C 2205/0323 20130101; F17C 2201/0109 20130101; F17C
2203/0341 20130101; F25J 3/04945 20130101; F17C 2227/0302 20130101;
F25J 3/04412 20130101 |
Class at
Publication: |
62/643 |
International
Class: |
F25J 3/00 20060101
F25J003/00 |
Claims
1-20. (canceled)
21. A cold box apparatus comprising: (a) a cryogenic assembly
comprising: (1) a main cryogenic element, and (2) an auxiliary
element having a first part and a second part, wherein said first
part is connected to said main cryogenic element, (b) an outer
jacket comprising: (1) an outer wall, (2) an inner wall, and (3) a
first space between said inner wall and said outer wall, wherein
said outer jacket surrounds at least some of said main cryogenic
element, and wherein there is a second space between said outer
jacket and said main cryogenic element, (c) a base, and (d) a
housing comprising an inner space, wherein said housing extends at
least partially outside said outer jacket, and wherein said second
part of said auxiliary element extends at least partially into said
inner space of said housing.
22. The apparatus of claim 21, wherein said auxiliary element is
selected from the group consisting of rotating equipment, pumps,
turboexpanders, instrument devices, valves, and piping.
23. The apparatus of claim 21, wherein said main cryogenic element
is selected from the group consisting of cryogenic columns,
sections of cryogenic columns, distillation columns, mixing
columns, storage vessels, pressure vessels, heat exchangers, and
combinations thereof.
24. The apparatus of claim 21, wherein said second space is at
least partially filled with insulating material.
25. The apparatus of claim 21, wherein said housing is attached to
the inner wall of said outer jacket.
26. The apparatus of claim 21, further comprising a thermal
insulator filling at least part of said first space.
27. The apparatus of claim 26, wherein said thermal insulator
comprises perlite.
28. The apparatus of claim 21, wherein said housing is made of a
material selected from the group consisting of steel, stainless
steel, aluminum, and alloys thereof.
29. The apparatus of claim 21, wherein said auxiliary element is
insulated from said main cryogenic element by a barrier.
30. The apparatus of claim 28, wherein said barrier is made of
material selected from the group consisting of perlite,
vermiculite, rock wool, and metal.
31. The apparatus of claim 21, wherein said base and said inner
wall are impermeable to liquid leaking from said cryogenic
assembly.
32. The apparatus of claim 21, further comprising a sealing plate,
wherein said sealing plate and said inner wall are impermeable to
liquid.
33. The apparatus of claim 21, wherein said apparatus is bolted to
the deck of a ship.
34. A cryogenic plant comprising the apparatus of claim 21.
35. An air distillation plant apparatus comprising the apparatus of
claim 32.
Description
BACKGROUND
[0001] The present invention relates to a cold box and a cryogenic
plant including a cold box. It applies in particular to cold boxes
containing cryogenic liquefiers and/or cryogenic distillation
plants and especially applies to cold boxes located on ships. The
cryogenic distillation plant may be an air separation unit for
production of oxygen and/or nitrogen for off shore applications
such as drilling platforms.
[0002] U.S. Pat. No. 6,101,840 describes a cold box having a
protuberance containing part of an air separation unit. It is not
possible to gain access to the contents of the protuberance without
damaging the cold box.
[0003] U.S. Pat. No. 6,360,545 describes a cold box for shipboard
use, wherein the cold box contains an air separation unit.
[0004] U.S. Pat. No. 6,378,331 describes a cold box for shipboard
use wherein the cold box contains columns and main heat exchanger
of an air separation unit. The cold box includes a double walled
structure containing perlite between the walls and the elements of
the air separation unit are housed within the inner wall of the
structure without any perlite around them.
[0005] "Tonnage Nitrogen Generation for Oil and Gas Enhanced
recovery in the North Sea" by Goldstone and Ralston presented in
the Annual Report, Session 6 of the 9.sup.th Continental Meeting of
Gas Processors Association, 1992 describes an air separation unit
for use on an oil platform.
SUMMARY
[0006] It is an objective of the invention to provide a cold box
with improved safety in particular for off shore applications, such
as Fischer Tropsch conversion.
[0007] It is another objective of the invention to facilitate
maintenance of elements of the cold box.
[0008] According to the invention, there is provided a cold box,
which will allow for improved access to facilitate maintenance of
elements within a cold box comprising: [0009] (a) a cryogenic
assembly comprising the main cryogenic elements and additional
auxiliary elements, wherein each main cryogenic element is selected
from the group consisting of cryogenic columns, sections of such
columns, storage vessels, heat exchangers and superposed
combinations thereof; [0010] (b) an outer jacket surrounding at
least some of the main cryogenic elements of the cryogenic
assembly, wherein the outer jacket has an outer wall and an inner
wall, and [0011] (c) a base; and [0012] (d) a housing, wherein the
housing contains at least one of the auxiliary elements and the
auxiliary element extends at least partially outside the outer
jacket, and that particular auxiliary element is connected to at
least one of the main cryogenic elements within the outer
jacket.
[0013] Typically, there is at least one thermal insulator filling
at least part of the space between the inner and outer walls of the
outer jacket. Other optional features may include one or more of
the following: [0014] the auxiliary element is selected from the
group comprising pumps, turboexpanders, valves and piping; [0015]
each main cryogenic element is selected from the group consisting
of distillation columns, mixing columns, storage vessels, heat
exchangers and superposed combinations thereof; [0016] there is
free space between the cryogenic assembly and the inner wall of the
outer jacket; [0017] the housing is attached to the inner wall of
the outer jacket; [0018] at least one thermal insulator is perlite;
[0019] the housing is made a material chosen from the group
comprising steel and aluminium; [0020] the auxiliary element is
insulated from the cryogenic assembly within the outer jacket by a
barrier; [0021] the barrier forms a weak seal, such as in the case
of over pressure within the housing, the insulation barrier breaks;
[0022] the barrier is made of material chosen from the group
comprising perlite, vermiculite, rock wool and metal; [0023] the
housing is situated from about 1 to from about 5 meters above the
base; [0024] the base and inner walls are impermeable to liquid
leaking from the cryogenic assembly; [0025] the housing extends
within the space between the inner and outer walls of the outer
jacket; and
[0026] the base and inner wall of the outer jacket are impermeable
to liquid.
[0027] According to additional embodiments of the invention, the
cold box may be applied to cryogenic plant, an air distillation
plant, or to a ship.
[0028] The main cryogenic elements are elements, which normally
function at temperatures below -50.degree. C.
[0029] The auxiliary element within the housing may also function
at a temperature of below -50.degree. C.
BRIEF DESCRIPTION OF DRAWINGS
[0030] For a further understanding of the nature and objects for
the present invention, reference should be made to the following
detailed description, taken in conjunction with the accompanying
drawings, in which like elements are given the same or analogous
reference numbers and wherein:
[0031] FIG. 1 is an illustration of one embodiment of the
invention; and
[0032] FIG. 2 is an illustration of a second embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] According to the invention, there is provided a cold box,
which will allow for improved access to facilitate maintenance of
elements within a cold box comprising: [0034] (a) a cryogenic
assembly comprising the main cryogenic elements and additional
auxiliary elements, wherein each main cryogenic element is selected
from the group consisting of cryogenic columns, sections of such
columns, storage vessels, heat exchangers and superposed
combinations thereof; [0035] (b) an outer jacket surrounding at
least some of the main cryogenic elements of the cryogenic
assembly, wherein the outer jacket has an outer wall and an inner
wall, and [0036] (c) a base; and [0037] (d) a housing, wherein the
housing contains at least one of the auxiliary elements and the
auxiliary element extends at least partially outside the outer
jacket, and that particular auxiliary element is connected to at
least one of the main cryogenic elements within the outer
jacket.
[0038] Typically, there is at least one thermal insulator filling
at least part of the space between the inner and outer walls of the
outer jacket. Other optional features may include one or more of
the following: [0039] the auxiliary element is selected from the
group comprising pumps, turboexpanders, valves and piping; [0040]
each main cryogenic element is selected from the group consisting
of distillation columns, mixing columns, storage vessels, heat
exchangers and superposed combinations thereof; [0041] there is
free space between the cryogenic assembly and the inner wall of the
outer jacket; [0042] the housing is attached to the inner wall of
the outer jacket; [0043] at least one thermal insulator is perlite;
[0044] the housing is made a material chosen from the group
comprising steel and aluminium; [0045] the auxiliary element is
insulated from the cryogenic assembly within the outer jacket by a
barrier; [0046] the barrier forms a weak seal, such as in the case
of over pressure within the housing, the insulation barrier breaks;
[0047] the barrier is made of material chosen from the group
comprising perlite, vermiculite, rock wool and metal; [0048] the
housing is situated from about 1 to from about 5 meters above the
base; [0049] the base and inner walls are impermeable to liquid
leaking from the cryogenic assembly; [0050] the housing extends
within the space between the inner and outer walls of the outer
jacket; and [0051] the base and inner wall of the outer jacket are
impermeable to liquid.
[0052] According to additional embodiments of the invention, the
cold box may be applied to cryogenic plant, an air distillation
plant, or to a ship.
[0053] The main cryogenic elements are elements, which normally
function at temperatures below -50.degree. C.
[0054] The auxiliary element within the housing may also function
at a temperature of below -50.degree. C.
[0055] FIG. 1 illustrates a cut away view of an air distillation
plant according to one embodiment of the invention. The invention
and its corresponding embodiments, is described below in relation
to cold boxes containing an air separation unit, but also applies
to cold boxes containing additionally, or alternatively, at least
one storage tank for cryogenic liquids.
[0056] The air distillation plant comprises a main cryogenic
element, such as a high-pressure column 1 and a low-pressure column
3, which are thermally integrated. The two columns are placed
within an outer jacket 7 having a circular cross section. The outer
jacket 7, also referred to herein as the cold box, is made of
resilient metal, such as stainless steel or aluminum, is placed on
top of a metal framework, sometimes known as a "pancake", which is
fastened to the deck 27 of a ship or floating platform.
[0057] Cooled compressed air to be sent to the high-pressure column
is sent to a heat exchanger (not shown) outside the cold box via
piping duct 9. The piping duct also carries conduits containing
product and waste steams from the columns. One of the products is a
pressurised liquid oxygen stream, which is to be vaporised in the
heat exchange line. The liquid oxygen is removed from the
low-pressure column, pressurised by an auxiliary element 16, such
as a pump, and sent to the piping duct 9 in a conduit. The pump is
located in a housing 13, which extends through an opening in the
outer jacket such that the housing is directly accessible from
outside the outer jacket 7. The housing 13 is made of resilient
metal, such as stainless steel or aluminium. The space between the
cold box and the columns is filled at least partially with
particulate insulation material, such as perlite.
[0058] The cold box illustrated has a circular cross-section, but
any cross-section could be used.
[0059] The low-pressure column 3 is placed on a structure 11 so as
to prevent cold migration to the ship or platform deck 27, which
could cause the carbon steel structure of the ship to fracture. The
high-pressure column 1 is similarly insulated from the deck.
[0060] As shown in FIG. 2, the housing 13 is sealed into an opening
in the outer jacket 7, preferably welded to the inner wall 31, such
that the perlite cannot escape. The housing is insulated from the
interior of the cold box using a rock wool layer 15 and a
non-resilient metal wall 17, such as an expanded metal layer. These
layers form a weak link, which will break in the case of
over-pressure allowing the liquid oxygen to flow back into the cold
box 7.
[0061] The housing 13 is in the form of a cuboid that has an inner
space 14 and a base wall 29 which slopes downwards towards the deck
27 of the ship, to assist the flow of any leaking liquid oxygen
back into the cold box 7 after breaking through the metal wall 17.
The housing may have any suitable shape.
[0062] The base 12 of the cold box is insulated using a layer of
foam glass 19 covered by a sealing plate 21. The bottom of both
column structures 11 is partially filled with a layer of rock wool
23.
[0063] The cold box may also be opened via an access door 25.
[0064] The housing 13 is insulated using perlite or rock wool and
as well as (or instead of) a pump or pumps and their associated
piping may contain at least one turboexpander and/or at least one
valve and/or other piping.
[0065] The outer jacket 7 has an inner wall 31 and an outer wall
33, at least part of the space between the two being filled with
perlite 35 in loose form or in the form of bricks. If the insulant
is in the form of bricks, the inner wall of the jacket may be
formed by the sidewalls of the bricks or may be a separate
panel.
[0066] The sealing plate 21 and inner walls 31 of the outer jacket
are impervious to liquid, so that if any cryogenic liquid escapes
from the air separation unit will collect in the bottom of the cold
box and eventually evaporates or is vaporised using a
vaporiser.
[0067] A relief valve may be provided so that vapors leaking from
the cryogenic unit may escape from the outer jacket.
[0068] One skilled in the art will appreciate that the air
separation unit may have any number of columns. For example, it may
comprise a single column, a double column, or a triple column.
Additionally, a mixing column or an argon production column may be
used.
[0069] The invention has been described in relation to cold boxes
containing an air separation unit, but also applies to cold boxes
containing additionally or alternatively, at least one storage tank
for cryogenic liquids. It also applies to cold boxes containing a
liquefier for producing cryogenic liquids.
[0070] Similarly, the air separation unit could be replaced by any
cryogenic distillation unit, such as a unit for separating a
mixture having principal components in the group comprising
hydrogen, helium, methane, nitrogen, and carbon monoxide. The
methods to make such a replacement are well known to those skilled
in the art.
[0071] The invention also relates to cold boxes in which cryogenic
liquids other than oxygen is pumped, such as nitrogen. The skill to
do such an application is well known to those skilled in the
art.
[0072] Preferred processes and apparatus for practicing the present
invention have been described. It will be understood and readily
apparent to the skilled artisan that many changes and modifications
may be made to the above-described embodiments without departing
from the spirit and the scope of the present invention. The
foregoing is illustrative only and that other embodiments of the
integrated processes and apparatus may be employed without
departing from the true scope of the invention defined in the
following claims.
* * * * *