U.S. patent application number 13/731013 was filed with the patent office on 2014-01-16 for thermal insulation technique for ultra low temperature cryogenic processor.
This patent application is currently assigned to Reflect Scientific, Inc.. The applicant listed for this patent is Boyd Bowdish, John Dain, Nick Henneman. Invention is credited to Boyd Bowdish, John Dain, Nick Henneman.
Application Number | 20140013778 13/731013 |
Document ID | / |
Family ID | 44562710 |
Filed Date | 2014-01-16 |
United States Patent
Application |
20140013778 |
Kind Code |
A1 |
Dain; John ; et al. |
January 16, 2014 |
THERMAL INSULATION TECHNIQUE FOR ULTRA LOW TEMPERATURE CRYOGENIC
PROCESSOR
Abstract
Systems and methods are disclosed to provide a cryogenic
processor apparatus with an outer housing; an inner housing coupled
to the external housing to define a vacuum region there between;
and material disposed in the vacuum region to provide redundant
insulation and structural support at a cryogenic temperature.
Inventors: |
Dain; John; (Hollister,
CA) ; Bowdish; Boyd; (Los Gatos, CA) ;
Henneman; Nick; (Tres Pinos, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dain; John
Bowdish; Boyd
Henneman; Nick |
Hollister
Los Gatos
Tres Pinos |
CA
CA
CA |
US
US
US |
|
|
Assignee: |
Reflect Scientific, Inc.
Orem
UT
|
Family ID: |
44562710 |
Appl. No.: |
13/731013 |
Filed: |
December 30, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
12984206 |
Jan 4, 2011 |
8541623 |
|
|
13731013 |
|
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|
11934696 |
Nov 2, 2007 |
7823394 |
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12984206 |
|
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Current U.S.
Class: |
62/51.1 ;
220/560.1 |
Current CPC
Class: |
B01J 4/002 20130101;
B01J 2219/00108 20130101; B01J 2219/00162 20130101; B01J 2219/00231
20130101; B01J 19/0066 20130101; B01J 2219/00186 20130101; F17C
13/001 20130101; B01J 2219/002 20130101; B01J 10/00 20130101 |
Class at
Publication: |
62/51.1 ;
220/560.1 |
International
Class: |
F17C 13/00 20060101
F17C013/00 |
Claims
1) A cryogenic processor apparatus, comprising: a) an outer
housing; b) an inner housing coupled to the external housing to
define a vacuum region there between; c) material disposed in the
vacuum region to provide redundant insulation and structural
support at a cryogenic temperature.
2) The apparatus of claim 1, wherein the material comprises an
insulation material with one of: a silica micro balloon,
polyisocyanurate.
3) The apparatus of claim 1, wherein the vacuum region is processed
using a novel method of removing residual water vapor and other
partial pressure of contaminants.
4) The apparatus of claim 1, wherein the vacuum region is evacuated
to a partial pressure of approximately 0.2 milliTorr.
5) The apparatus of claim 1, comprising a cryogenic heat exchanger
with one or more tubings.
6) The apparatus of claim 5, where in the cryogenic heat exchanger
comprises one or more tubings including redundant tubings.
7) The apparatus of claim 5, wherein the cryogenic heat exchanger
comprises U-shaped tubings covering at least three walls of the
payload bay.
8) The apparatus of claim 5, wherein the cryogenic heat exchanger
comprises tubings covering at least four sides of the payload
bay.
9) The apparatus of claim 5, wherein the cryogenic heat exchanger
comprises a port coupled to one or more tubings to provide input
and output connections thereto.
10) The apparatus of claim 5, comprising a door coupled to the
payload bay, wherein the door comprises three or more materials
having different thermal characteristics.
11) A method to provide ultra low temperature processing and/or
storage, comprising: a) providing insulation and structural support
using a material disposed in a vacuum region between an external
housing and an inner housing; and b) cryogenically processing one
or more compartments contained in a payload bay.
12) The method of claim 11, wherein the material comprises an
insulation material with silica micro balloon technology.
13) The method of claim 11, comprising removing water vapor,
partial pressure contaminates and atmospheric gases from the vacuum
region.
14) The method of claim 11, comprising evacuating the vacuum region
to approximately 0.2 millitorr.
15) The method of claim 11, wherein the cryogenic heat exchanger
comprises one or more heat exchange tubings.
16) The method of claim 11, wherein the cryogenic heat exchanger
comprises primary heat exchange tubings including redundant
tubings.
17) The method of claim 16, wherein the redundant tubings comprise
one of: tubings branched from the primary heat exchange tubings,
tubings operating in parallel with the primary heat exchange
tubings, U-shaped tubings covering at least three walls of the
inner housing.
18) The method of claim 11, comprising providing a door adapted to
seal a chamber in the payload bay, wherein the door comprises a
plurality of materials each having different thermal
characteristics.
19) The method of claim 11, comprising providing a changeable rack
assembly in the chamber.
20) The method of claim 19, comprising transmitting energy from the
payload bay into the heat exchanger through the changeable rack
assembly.
21) The method of claim 11, comprising providing a negative
pressure in the payload bay.
22) The method of claim 21, comprising providing pneumatic seals on
the main door assembly and cryogenics vacuum pumping through the
heat exchanger to remove thermal energy from the payload bay and
into the heat exchanger.
23) The method of claim 1, wherein at least one of the external
housing and the inner housing comprises a flat surface.
Description
[0001] This application is a continuation of application Ser. No.
11/934,696 filed on Nov. 2, 2007 and 12/984,206, filed Sep. 30,
2010, the content of which is incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a thermal insulation technique for
ultra low temperature cryogenic processors.
[0003] Vacuum insulating panels are used conventionally for thermal
insulation. Known vacuum insulating panels consist of a
pre-compressed porous filling, a porous pressboard or an open-cell
rigid foam as substrate, which is enveloped by a gas-tight film,
wherein the film is heat-seated or bonded after the evacuation.
[0004] The following, for example, are used as filling materials
for vacuum insulating panels: precipitated and dried silicas,
silica gels, fly ash, open-cell foams on an organic base such as
open-cell rigid polyurethane foams or bonded rigid polyurethane
foam paste. Vacuum insulating panels of this type are used in the
manufacture of cold rooms, e.g., refrigerators or refrigerated
containers, with the latter being inserted between the outer and
inner casing and the gap left between the outer and inner casing
being filled with foam.
[0005] The fitting of the vacuum insulation panels into
refrigerator casings nevertheless presents problems. According to
the current state of the art, they are bonded onto a plate--for
example, a metal cassette--by means of a double-sided adhesive
film. This combination plate can then be processed further into a
sandwich panel, for example, a refrigerator door, wherein the
cavity left is conventionally filled with foam.
[0006] As a result, on the one hand, a complicated, multi-step
process is required, and on the other hand, the insulation volume
is affected by the foam, which is less efficient in insulation
terms when compared with a vacuum insulation panel. Arrangements of
this type are also, to only a limited extent, without thermal
bridges.
[0007] U.S. Pat. No. 6,164,030 discloses an apparatus which
consists of a rigid plate and a vacuum insulation panel, in which
the vacuum insulation panel is fixed to the rigid plate by a
polyurethane foam applied as a liquid reaction mixture, wherein the
vacuum insulation panel contains open-cell rigid plastics foam
and/or open-cell rigid plastics foam recyclate.
SUMMARY
[0008] In a first aspect, systems and methods are disclosed to
provide a cryogenic processor apparatus with an outer housing; an
inner housing coupled to the external housing to define a vacuum
region there between; and material disposed in the vacuum region to
provide redundant insulation and structural support at a cryogenic
temperature.
[0009] In another aspect, systems and methods are disclosed to
provide an ultra low temperature (ULT) cryogenic processor
apparatus. The apparatus includes an external housing with flat
sides; an inner housing coupled to the external housing to define a
vacuum region there between; material disposed in the vacuum region
to provide redundant insulation and structural support; and a
cryogenic heat exchanger contained in the inner housing.
[0010] Implementations of the above aspect may include one or more
of the following. The material can be an insulation material with
one of: a silica micro balloon, polyisocyanurate. The vacuum region
can be processed by removing residual water vapor and other partial
pressure of contaminants. The vacuum region is evacuated to a
partial pressure of approximately 0.2 milliTorr. The cryogenic heat
exchanger can include one or more tubings and may include redundant
tubings. The cryogenic heat exchanger can be U-shaped tubings
covering at least three walls of the payload bay. The cryogenic
heat exchanger can include tubings covering at least four sides of
the payload bay. Alternatively, the cryogenic heat exchanger can be
one or more coils positioned on the top and/or the bottom of the
vessel. A port can connect to the one or more tubings to provide
input and output connections thereto. A door can allow access to
the payload bay, wherein the door comprises three or more materials
having different thermal characteristics.
[0011] In another aspect, a method to provide ultra low temperature
processing and/or storage includes providing insulation and
structural support using a material disposed in a vacuum region
between an external housing and an inner housing; and cryogenically
processing one or more compartments contained in the payload
bay.
[0012] Implementations of the above aspect may include one or more
of the following. The material can be an insulation material with
silica micro balloon technology. The process can remove water
vapor, partial pressure contaminates and atmospheric gases from the
vacuum region. The process includes evacuating the vacuum region to
approximately 0.2 millitorr. The cryogenic heat exchanger can have
one or more heat exchange tubings, and can include redundant
tubings. The redundant tubings can be a complete set of heat
exchange tubings operating in parallel with the primary heat
exchange tubings. The redundant tubings can have one or more
tubings branched from the primary heat exchange tubings. The
cryogenic heat exchanger can also include U-shaped tubings covering
at least three walls of the inner housing. The tubings can cover at
least four sides of the inner housing. A door can be formed with a
plurality of materials each having different thermal
characteristics. A changeable rack assembly is supported in the
chamber. The system can transmit energy from the payload bay into
the heat exchanger through the changeable rack assembly. A negative
pressure in the payload bay can be maintained through the use of
pneumatic seals on the main door assembly. The cryogenics vacuum
pumping via the heat exchanger can provide energy removal from the
payload bay and into the heat exchanger. The surfaces of at least
one of the external and inner housing can be flat surfaces.
[0013] In another aspect, a method to insulate a vessel includes
placing a plurality of shells on all sides of the vessel without
providing a direct energy pathway from outer walls of the vessel to
the inner walls of the vessel; placing the shells under a vacuum;
cryogenically cooling the shells to a cryogenic temperature; and
while under vacuum, allowing the shell temperature to rise from the
cryogenic temperature to ambient temperature.
[0014] Implementations of the above aspect may include one or more
of the following. The process can include milling spaced-apart
pathways in the shells. Such millings facilitate an evacuation of
the trapped spaces of the shells and allowing for a desorbtion of a
surface area of the shells. A vacuum pump can maintain a partial
pressure of the vacuum in the vessel to below approximately 10
millitorr. The vacuum pump is a non-oil based pump. Initially, the
process evacuates the shells to a total pressure of approximately
500 millitorr. The process then cryogenically cools the shells to a
temperature of less than approximately -175.degree. C. Next,
gettered gases can be removed by a pseudo thermo/kinetic energy
transfer during the rise to ambient temperature. The shells can be
a foam material. The shell layout prevents heat gain energy from
migrating from the outer walls to the inner walls by presenting at
least two 90 degree flow pathway changes.
[0015] In another aspect, an insulated vessel includes outer walls;
inner walls spaced apart from the outer walls to define a vacuumed
insulation volume; and a plurality of shells placed in the
insulation volume without providing a direct energy pathway from
outer walls of the vessel to the inner walls of the vessel, wherein
the shells are cryogenically cooled to a cryogenic temperature and
while under vacuum, the shell temperature is raised from the
cryogenic temperature to ambient temperature.
[0016] Implementations of the above aspect may include one or more
of the following. Spaced-apart pathways can be milled in the
shells. The pathways facilitate an evacuation of the trapped spaces
of the shells and allowing for a desorbtion of a surface area of
the shells. A vacuum pump can maintain a partial pressure of the
vacuum in the insulation volume to below approximately 10
millitorr. The vacuum can be provided using a non-oil based pump.
The pump can initially evacuate the insulation volume to a total
pressure of approximately 500 millitorr. A cryogenic heat exchanger
can cryogenically cool the shells to a temperature below
approximately -175.degree. C. Gettered gases can be removed by a
pseudo thermo/kinetic energy transfer during the rise to ambient
temperature. Each shell can be a foam material. The shells prevent
heat gain energy from migrating from the outer walls to the inner
walls by presenting at least two 90 degree flow pathway
changes.
[0017] Advantages of the preferred embodiment may include one or
more of the following. The system has a thermal insulation
technique that combines a highly non-compressible foam and
traditional vacuum processing techniques to produce a novel
insulation technique. This technique can be used to reduce the heat
gain properties of a low temperature vessels and allow for the
manufacture of square, flat walled vacuum chambers that demonstrate
no structural deformation or metal fatigue during the evacuation
process. The theoretical R-value of this technique is greater then
100 as measured by the International System of Units--RSI.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows an exemplary process to insulate a vessel.
[0019] FIG. 2 shows an exemplary shell arrangement.
[0020] FIG. 3 shows an assembly of the vessel with outer walls,
shells, and the payload chamber.
[0021] FIG. 4 shows an exemplary payload chamber enclosed by the
shell.
[0022] FIG. 5 shows an exemplary cold vacuum processing
operation.
DESCRIPTION
[0023] FIG. 1 shows an exemplary process to insulate a vessel such
as a biological storage chamber, among others. The process forms a
plurality of foam shells on all sides of a vessel without a direct
energy pathway from outer walls of the vessel to the inner walls of
the vessel (1). Next, the process places the foam shells under
vacuum (2). The process then cryogenically cools the foam shells
(3); and while under vacuum, allowing the foam shell temperature to
rise from a cryogenic temperature to an ambient temperature
(4).
[0024] FIG. 2 shows an exemplary shell arrangement. The shell can
be made of foam, among other materials. In FIG. 2, two outside back
shell portions 25 and 26 are positioned adjacent each other.
Portions 25 in turn faces inner back shell portions 27 and 33.
These portions in turn are surrounded on left and right sides by a
pair of side shell assembly having an outside side shell portions
28 and 29 that face inside side shell portions 30 and 31. The back
shell portions and the side shell portions are in turn connected to
top and bottom shell assemblies. The bottom shell assembly includes
outer bottom shelf portions 19 and 34 facing inner bottom shelf
portions 20-21. The top shell assembly includes outer top shelf
portions 22 and 32 that face inner top shelf portions 23-24. The
top shell assembly include openings 22 that allow cryogenic
coolants to enter and exit a payload chamber as shown in more
details below.
[0025] In one embodiment, each foam piece is four inches thick and
is made from a polyisocyanurate material. The vacuum vessel is made
of austenitic stainless steel, type 302, 304, 316, 321 or 347. The
foam design places foam sections on all sides of a vessel and will
be designed so that there are no direct energy pathways from the
outer walls to the inner wall. The arrangement challenges any heat
gain energy from migrating from the outer wall to the cryogenically
tempered inner surface by presenting at least two 90 degree flow
pathway changes. All energy migrating from outer to inner is
gettered by the kinetic properties of the foam, while in molecular
flow regime. All foam sections will have vacuum pathways milled
into them which are 0.065'' in cross section, spaced in an
arrangement that facilitates the evacuation of the trapped spaces
of the foam sections and allowing for the desorbtion of the surface
area of the foam to a minimum of 100 monolayers in one embodiment.
After the milling operation, the foam itself has enough surface
area and flow obstructions as to prevent serious back flow of
contaminates into the vacuum space. Vacuum channels are placed on
the foam to allow for two processes to happen. First, the channels
facilitate the general evacuation of the chambers and second, the
channels facilitate the desorbtion of water vapor from the foam
surface. The vacuum processing reduces the partial pressure of the
vacuum vessel to a point lower than 10 millitorr as measured by a
thermocouple or similar total pressure gauge. The use of non-oil
based vacuum pumps prevents the back streaming of residual water
and oil vapor with its contaminating gas load.
[0026] In addition to using oil free vacuum pumps, a cold
processing technique is applied to the shells. The technique
includes of three separate steps.
[0027] Firstly, the assembly is evacuated to a total pressure of
approximately 500 millitorr. The specific ultimate pressure is not
important.
[0028] Secondly, the assembly is then cryogenically cooled to a
temperature of no more then -175.degree. C. as measured on the
inner wall of the vacuum chamber. This getters contaminant gases
onto the inner wall of the vacuum chamber via thermodynamic
processes, thus conditioning the foam.
[0029] Lastly, while the vacuum pump system is connected and
applied to the vacuum chamber, the temperature is allowed rise to
ambient. The vacuum pump removes all of the gettered gases by way
of a pseudo thermo/kinetic energy transfer.
[0030] The following examples are intended to explain the invention
in greater detail, but without limiting it in its scope. In one
exemplary embodiment, the foam is a Polyisocyanurate Insulation
that has the following specifications: [0031] Compressive Strength
3 D 1621 lb/in2 kPa [0032] Parallel to Rise (Thickness) 140 970
[0033] Perpendicular to Rise (Width) 130 900 [0034] Perpendicular
to Rise (Length) 130 900 [0035] Compressive Modulus D 1621 lb/in2
kPa [0036] Parallel to Rise (Thickness) 3100 21400 [0037]
Perpendicular to Rise (Width) 2800 19300 [0038] Perpendicular to
Rise (Length) 2800 19300 [0039] Shear Strength C 273 lb/in2 kPa
[0040] Parallel to Rise 80 550 [0041] Shear Modulus C 273 lb/in2
kPa [0042] Parallel to Rise 800 5500 [0043] Tensile Strength D 1623
lb/in2 kPa [0044] Parallel to Rise (Thickness) 80 550 [0045]
Tensile Modulus D 1623 lb/in2 kPa [0046] Parallel to Rise
(Thickness) 2800 19300 [0047] Flexural Strength C 203 lb/in2 kPa
[0048] Parallel to Rise 160 1100 [0049] Flexural Modulus C 203
lb/in2 kPa [0050] Parallel to Rise 5800 40000 [0051] k-Factor
(75.degree. F. (24.degree. C.) mean temp.) C 518 [0052]
BTUin/hrft2.degree. F. W/m.degree. C. [0053] Initial 0.180 0.026
[0054] Aged 180 days @ 75.degree. F. (24.degree. C.) 0.200 0.029
[0055] R-Value/in (75.degree. F. (24.degree. C.) mean temp.) C 518
[0056] Hrft2.degree. F./BTU m2.degree. C./W [0057] Initial 5.5 0.97
[0058] Aged 180 days @ 75.degree. F. (24.degree. C.) 5.0 0.88
[0059] Closed Cell Content D 2856% 97% 97 [0060] Water Absorption C
272% by Volume 0.7% by Volume 0.7 [0061] Water Vapor Permeability E
96 Perm-Inch 1.1 [0062] (ng/Pasm) 1.6 [0063] Dimensional Stability
4 D 2126 [0064] @ -40.degree. F. (-40.degree. C.), 7 days [0065]
Length % Change -0.3% Change -0.3 [0066] Volume % Change -0.1%
Change -0.1 [0067] @ 158.degree. F. (70.degree. C.)/97% Relative
Humidity, 7 days [0068] Length % Change 0.4% Change 0.4 [0069]
Volume % Change 0.7% Change 0.7 [0070] @ -10.degree. F.
(-23.degree. C.), 7 days [0071] Length % Change -0.2% Change -0.2
[0072] Volume % Change -0.7% Change -0.7 [0073] @ 300.degree. F.
(149.degree. C.), 7 days [0074] Length % Change -0.4% Change -0.4
[0075] Volume % Change -1% Change -1 [0076] Service Temperature
5.degree. F. -297 to +300.degree. C. -183 to +149
[0077] FIG. 3 shows an assembly of a vessel 110 with outer walls,
shells, and inner walls formed by the exterior of the payload
chamber. FIG. 3 shows the five-sided outer "tub" 110A assembled
with a lining of insulation, into which is inserted metal inner
"tub" 124, typically of 16 gauge stainless steel, having a front
flange which extends around the perimeter. This is seamlessly
laser-welded to the alter tub 110 all around in a no leak manner to
form an insulation tub 110B with the five hollow walls totally
enclosed and filled with the shell portions 112, 122, 116, 118, 120
and 122. More details on the vessel 110 are disclosed in co-pending
application Ser. No. 11/890,451, filed on Aug. 7, 2007, the content
of which is incorporated by reference.
[0078] FIG. 4 shows an exemplary assembled payload chamber enclosed
by an insulation volume where the shells are placed. In one
embodiment, this shell portions can be first purged of moisture at
120 degrees C. then evacuated at 100 degrees C. to a vacuum of
approximately 0.0002 torr (i.e. 02 millitorrs, 1 torr=1/760
atmosphere) and then sealed off as a vacuum-insulation-walled
enclosure.
[0079] The rigidity and high compressive strength of the shell
material serve to counteract and minimize inward bending distortion
of the two opposed metal sheets due to stress from the internal
vacuum and external atmospheric pressure as the shell material
provides sufficient compressive strength.
[0080] FIG. 5 shows an exemplary cold vacuum processing operation.
First, the vessel is constructed (200) and a visual inspection is
done (202) in accordance with a manufacturing protocol (204). If
the visual inspection passes, a primary evacuation operation is
done (206). The primary evacuation can be done using a mechanical
pump (208). After the primary evacuation, a pressure reading is
done (210). The reading tests that a total pressure of about 500
millitorr is in the chamber within 60 minutes (212). Next, the
system performs a leak check using an atmospheric helium leak
detector (222). The system confirms that the leak rate is less than
10 e-6 atm-cc/sec in one embodiment (223). Next, the system is
cooled to less than -175 degree C. (224) while a continual vacuum
pumping dual stage turbo molecular pump is operated (225). Next, a
pressure reading is taken (226). Preferably, the pressure is less
than 10 millitorr (228). The system also checks for leak using the
atmospheric helium leak detector (230). The helium leak rate is
ascertained (232). The temperature of the vessel is then allowed to
rise to ambient temperature while under vacuum (234). A final
ultimate pressure evacuation is done (236) and the vessel is sealed
(240).
[0081] Although the invention has been described in detail in the
foregoing for the purpose of illustration, it is to be understood
that such detail is solely for that purpose and that variations can
be made therein by those skilled in the art without departing from
the spirit and scope of the invention except as it may be limited
by the claims.
* * * * *