U.S. patent application number 16/880533 was filed with the patent office on 2020-11-26 for thermally insulated enclosure containing equipment intended to operate at a temperature below 0.degree.c.
This patent application is currently assigned to L'Air Liquide, Societe Anonyme pour l'Etude et l?Exploitation des Procedes Georges Claude. The applicant listed for this patent is L'Air Liquide, Societe Anonyme pour I'Etude et I'Exploitation des Procedes Georges Claude. Invention is credited to Maxime BUTLER, Benoit DAVIDIAN.
Application Number | 20200370826 16/880533 |
Document ID | / |
Family ID | 1000004881052 |
Filed Date | 2020-11-26 |
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United States Patent
Application |
20200370826 |
Kind Code |
A1 |
BUTLER; Maxime ; et
al. |
November 26, 2020 |
THERMALLY INSULATED ENCLOSURE CONTAINING EQUIPMENT INTENDED TO
OPERATE AT A TEMPERATURE BELOW 0.degree.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.degree. 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.
Inventors: |
BUTLER; Maxime; (Vitry Sur
Seine, FR) ; DAVIDIAN; Benoit; (Vitry Sur Seine,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
L'Air Liquide, Societe Anonyme pour I'Etude et I'Exploitation des
Procedes Georges Claude |
Paris |
|
FR |
|
|
Assignee: |
L'Air Liquide, Societe Anonyme pour
l'Etude et l?Exploitation des Procedes Georges Claude
Paris
FR
|
Family ID: |
1000004881052 |
Appl. No.: |
16/880533 |
Filed: |
May 21, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25J 2290/30 20130101;
F25J 2290/12 20130101; F25J 3/04945 20130101 |
International
Class: |
F25J 3/04 20060101
F25J003/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 22, 2019 |
FR |
FR 1905376 |
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.degree. 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.degree. 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
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority wider 35
U.S.C. .sctn. 119 (a) and (b) to French patent application No.
FR1905376, filed May 22, 2019, the entire contents of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a thermally insulated
enclosure containing equipment intended to operate at a temperature
below 0.degree. C., or even at a cryogenic temperature that is at
least below -54.degree. C.
BACKGROUND OF THE INVENTION
[0003] Such enclosures are used to insulate a cryogenic
distillation column. Usually, the enclosure is filled with perlite,
but in order to improve the thermal insulation it is known practice
to apply a vacuum to the perlite-filled enclosure, in order to
improve the insulation. Vacuum-packed perlite is a conventional
high-performance thermal insulator used in cryogenic storage
facilities or else in cold boxes of cryogenic gas separation
units.
[0004] The outer shell of the storage facility or of the cold box,
which is essentially cylindrical or spherical in shape, is
mechanically dimensioned to withstand the vacuum, as a reverse
pressure, thereby requiring a thick wall that is expensive and
heavy.
[0005] The shape of the enclosure, having neither edges nor
corners, is dictated by the need to improve the resistance to
external pressure. As noted in FR2695714, a vacuum insulated
distillation column is, by definition, placed inside a cylindrical
enclosure. A cylindrical enclosure generally has ends which are
either hemispherical or semi-ellipsoidal.
[0006] Now, the parallelepipedal shape generally used when the
thermal insulation is not under vacuum offers a number of
advantages, particularly the greater ease of holding it in place
for transport and a better level of filling when a container is
used for transport, or else when the equipment, typically heat
exchangers of the brazed aluminium plate type, are parallelepipedal
in shape.
[0007] When a vacuum is applied to an enclosure of parallelepipedal
shape, the walls that form the enclosure are mechanically unable to
withstand the vacuum with a wall of small thickness.
[0008] In addition, when use is made of perlite in pulverulent
form, it has the disadvantage of settling down when the vacuum is
applied. The expanded perlite usually employed for thermally
insulating enclosures has an uneven shape and may break when
subjected to too high a pressure.
[0009] According to the prior art, an outer shell of cylindrical or
spherical shape is dimensioned to be able to mechanically withstand
the vacuum (namely to withstand the atmospheric pressure of 1 bara
applied to its exterior face): that requires a considerable wall
thickness, because of the reverse pressure, often combined with the
use of reinforcing hoops. Filling is achieved via an orifice in the
enclosure, then vacuum is applied, then the vacuum to is broken by
introducing perlite via the orifice. Thus, several cycles of
"applying a vacuum/breaking the vacuum with the addition of
perlite" are thus conducted until the perlite is properly settled
and the outer shell is properly filled. The final vacuum is then
applied, typically of around 10.sup.-1 to 10.sup.-3 mbara, so as to
ensure high-performance thermal insulation of the cryogenic storage
facility or of the cold box.
SUMMARY OF THE INVENTION
[0010] One subject of the invention provides a thermally insulated
enclosure having at least one surface that is planar, preferably
all the surfaces being planar, containing at least one piece of
equipment intended to operate at a temperature below 0.degree. C.,
or even at cryogenic temperature, the interior space of the
enclosure being intended to be at a pressure below atmospheric
pressure and being filled, preferably completely filled, with
thermal insulation and the thermal insulation being made up, in
respect of at least three-quarters of the volume thereof, of a
multitude of spherical beads made of thermally insulating material
and which are possibly hollow, having a diameter of at most 1 mm
and having a crush strength such that the volume of the entity
formed by the multitude of beads would reduce by at most 10%, or
even 5%, preferably by at most 1%, if the entity made up of the
multitude of beads were subjected to a pressure of 0.1 MPa.
[0011] According to other optional aspects: [0012] the walls of the
enclosure are not thick enough to withstand the vacuum if the
insulation had a crush strength such that its volume would reduce
by more than 10%, or even 5%, or if appropriate by more than 1% if
the enclosure were evacuated to a pressure below 10.sup.-1 mbara;
[0013] the enclosure is parallelepipedal in shape; [0014] the beads
are made of glass and/or of perlite and/or of vermiculite; [0015]
the enclosure has a minimum volume of 12 m.sup.3; [0016] the
enclosure consists of a container which 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 transhipped; [0017] the equipment comprises
or is at least one column intended to perform an exchange of heat
and/or of material and/or at least one heat exchanger and/or at
least one storage facility and/or at least one phase separator;
and/or [0018] the equipment is a column or a heat exchanger, the
equipment being of parallelepipedal shape.
[0019] Another aspect of the invention provides a method for
filling an enclosure as described hereinabove, wherein at least one
item of equipment is placed inside the enclosure, the enclosure is
filled with the multitude of beads, the enclosure is closed and at
least partially evacuated, preferably in a single evacuation
step.
[0020] Preferably, the enclosure is filled with 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.
[0021] Another aspect of the invention provides a method of
separation at a temperature below 0.degree. C. using distillation
and/or scrubbing, using an insulated enclosure of parallelepipedal
shape containing at least one piece of equipment, the interior
space of the enclosure being intended to be at a pressure below
atmospheric pressure and being filled with thermal insulation, the
thermal insulation being made up, in respect of at least
three-quarters of the volume thereof, of a multitude of spherical
beads made of thermally insulating material and which are possibly
hollow, having a diameter of at most 1 mm and having a crush
strength such that the volume of the entity formed by the multitude
of beads would reduce by at most 10%, or even 5%, preferably by at
most 1%, if the entity made up of the multitude of beads were
subjected to a pressure of 0.1 MPa, wherein the equipment
performing the separation operates at a temperature below 0.degree.
C., or even at cryogenic temperature, and at a preferably
above-atmospheric pressure, and the space filled with insulation is
evacuated to a pressure below atmospheric pressure, preferably
below 10.sup.-1 mbara.
[0022] The volume of the entity formed by the multitude of beads
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; that means that, for a multitude of beads
already at atmospheric pressure, if they were subjected to an
additional pressure of 0.1 MPa, the reduction in volume observed
would, at the very most, be that claimed.
[0023] Certain embodiments of the invention offer amongst others
the advantages of reducing the time and cost involved in installing
the insulated enclosure, of reducing the mass of the enclosure, and
of avoiding problems of deformation of the enclosure.
[0024] Certain embodiments of the invention can include use of an
enclosure of parallelepipedal shape, the thermal insulation of
which is able to withstand atmospheric pressure when under vacuum.
Certain embodiments of the method of manufacture can include
completely filling the outer shell with a pulverulent material in
the form of spherical or near-spherical beads, preferably under
gravity. The outer shell is then evacuated.
[0025] Because the material in the form of spherical beads is only
slightly compressible, this material is able to withstand the
mechanical force associated with the vacuum, while at the same time
pressing against the internal equipment inside the outer shell
(internal storage facility, distillation column, exchanger, piping,
separator vessel, valves, etc.) without deformation of the wall of
the outer shell: in this way, deformation of the outer shell is
avoided. The outer shell can therefore be simplified to a simple
fluidtight "skin" which contains the pulverulent material in order
to control the insulation distances before the vacuum is
applied.
[0026] The fluidtight outer shell is not dimensioned to
mechanically withstand the vacuum (namely to withstand the
atmospheric pressure of 1 bar applied to its exterior face). The
pressure forces will pass through the insulation, thanks to the use
of a pulverulent material that is incompressible or only slightly
compressible (namely of which the mechanical compression strength
is higher than the mechanical force to be transmitted), typically
glass beads (for example, the product K1 from 3M.RTM.) or perlite,
or else vermiculite.
[0027] The beads used have a diameter less than 1 mm, or preferably
than 800 microns or than 600 microns, or even than 500 or than 120
microns. The beads used preferably have a diameter greater than 10
microns, or even greater than 100 microns. They may be hollow.
[0028] The enclosure is filled by tipping the beads through an
opening, it being possible for the enclosure to be lying down or
upright. This opening may be formed 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, an opening
may be formed in the outer shell of the enclosure in order to allow
the beads to be installed therein.
[0029] The outer shell is completely filled with beads, essentially
under the effect of gravity. Vibration, or else tapping on the
wall, for example using a hammer or a mallet, may also be used to
help the beads to flow into all of the regions of the outer shell,
namely including the less accessible or "hidden" regions such as
underneath a support or piping, and limit the heaping effect. The
outer shell may be "tilted" so that all of the "empty" volume is
correctly filled under the effect of gravity, by placing it in
different positions.
[0030] The outer shell of small thickness may have a certain
rigidity in order to maintain a controlled geometric appearance
during the filling with the pulverulent insulating material, so as
to ensure the correct distances of insulation with respect to the
internal equipment. It is also possible to provide local supports
or spacers in order to contain the material dimensionally during
filling.
[0031] Once the enclosure is filled to the brim, it is closed. This
can be done by replacing the removed sheet metal panel mentioned
earlier. Otherwise, a lid, typically planar, which may be a simple
welded sheet metal panel, may be attached over the top of the
opening in a fluidtight manner. The sheet metal panel or the lid is
preferably incapable of withstanding the vacuum (namely the
atmospheric pressure of 1 bara) and will therefore need to rest on
the beads in order to avoid any unacceptable deformation during the
evacuation of the enclosure, the sheet metal panel or the lid thus
forming part of the shell. Alternatively, filling is performed
through a filling orifice which is then closed off by a blind
flange.
[0032] Once the enclosure is closed, the single operation of
applying the final vacuum, typically of around 10.sup.-1 to
10.sup.-3 mbara can be performed in order to ensure
high-performance thermal insulation of the cryogenic storage
facility or of the cold box, without having to top up with
insulating product and without fear of deforming the
small-thickness walls, the pressure forces being absorbed by the
insulation, while pressing against the internal equipment inside
the outer shell (internal storage facility, distillation column,
exchanger, piping, separator vessel, valves, etc.).
[0033] The collection of spherical beads with which the enclosure
is filled has a crush strength such that its volume would reduce by
at most 10%, or even 5%, preferably by at most 1%, if the beads
were subjected to a pressure of 0.1 MPa, namely typically the
pressure experienced if the enclosure is evacuated to a pressure
below 10.sup.-1 mbara, and assuming that the shell contributes no
mechanical strength. [0034] For all applications, there is a saving
on material for the outer shell (smaller thickness) and a saving in
evacuation with just one vacuum-pulling step. [0035] For a
distillation unit for which distillation takes place at at least
one temperature below 0.degree. C., or even at cryogenic
temperature involving a distillation column and/or a heat exchanger
which is/are contained in a parallelepipedal cold box or else in a
simple container, for example a container having the standardized
dimensions rendered fluidtight. [0036] For a cryogenic storage
facility for which the inside of the storage facility is at a
temperature below 0.degree. C., or even at cryogenic temperature in
which a gas or liquid reservoir is contained inside an insulated
enclosure of parallelepipedal shape that may be a container to
standardized dimensions. [0037] A lorry carrying a cryogenic
storage facility as described hereinabove.
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.RTM., 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.RTM. 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.
* * * * *