U.S. patent application number 14/991775 was filed with the patent office on 2016-07-14 for para-orthohydrogen conversion using a vortex tube.
The applicant listed for this patent is Washington State University. Invention is credited to Jacob William Leachman.
Application Number | 20160200570 14/991775 |
Document ID | / |
Family ID | 56356508 |
Filed Date | 2016-07-14 |
United States Patent
Application |
20160200570 |
Kind Code |
A1 |
Leachman; Jacob William |
July 14, 2016 |
Para-Orthohydrogen Conversion Using a Vortex Tube
Abstract
A para-orthohydrogen conversion device comprises a vortex tube.
The vortex tube may include an inlet disposed at a first end of the
vortex tube, a catalyst disposed on the interior wall of the vortex
tube, a first outlet comprising an opening on the perimeter of a
second end of the vortex tube, a stopper disposed at the center of
the second end of the vortex tube, and a second outlet disposed on
the first end of the vortex tube. A method includes converting
parahydrogen to orthohydrogen via the catalyst and rotational force
as hydrogen gas moves through the vortex tube such that cooled
parahydrogen-rich gas or liquid hydrogen accumulates near the
center of the vortex tube.
Inventors: |
Leachman; Jacob William;
(Pullman, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Washington State University |
Pullman |
WA |
US |
|
|
Family ID: |
56356508 |
Appl. No.: |
14/991775 |
Filed: |
January 8, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62101593 |
Jan 9, 2015 |
|
|
|
Current U.S.
Class: |
423/649 ;
422/222 |
Current CPC
Class: |
B01J 2219/00765
20130101; F25J 2205/10 20130101; B01J 19/2415 20130101; B01J
2219/00063 20130101; B01J 2219/00155 20130101; F25B 9/04 20130101;
B01J 2219/24 20130101; B01J 19/0053 20130101; B01J 2219/00186
20130101; B01J 19/006 20130101; B01J 2219/00164 20130101; B01J
2219/00159 20130101; B01J 19/2405 20130101; B01J 2219/00162
20130101; C01B 3/0089 20130101 |
International
Class: |
C01B 3/00 20060101
C01B003/00; B01J 19/24 20060101 B01J019/24 |
Claims
1. A method comprising: transferring hydrogen gas into a proximal
end of a vortex tube, at least a portion of an interior wall of the
vortex tube comprising a catalyst, wherein the hydrogen gas
comprises orthohydrogen and parahydrogen; flowing the hydrogen gas
toward a distal end of the vortex tube, the hydrogen gas rotating
within the vortex tube as the hydrogen gas flows toward the distal
end; reacting the hydrogen gas with the catalyst such that at least
a portion of the parahydrogen is converted to orthohydrogen;
expelling orthohydrogen-rich hydrogen gas from the distal end of
the vortex tube; and flowing parahydrogen-rich hydrogen gas out the
proximal end of the vortex tube.
2. The method of claim 1, wherein the hydrogen gas transferred into
the proximal end of the vortex tube comprises approximately 50%
orthohydrogen and approximately 50% parahydrogen.
3. The method of claim 1, wherein the orthohydrogen-rich hydrogen
gas comprises more orthohydrogen than parahydrogen.
4. The method of claim 1, wherein the orthohydrogen-rich hydrogen
gas comprises approximately 75% orthohydrogen and approximately 25%
parahydrogen.
5. The method of claim 1, wherein the parahydrogen-rich hydrogen
gas comprises more parahydrogen than orthohydrogen.
6. The method of claim 1, wherein the parahydrogen-rich hydrogen
gas comprises approximately 75% parahydrogen and approximately 25%
orthohydrogen.
7. The method of claim 1, wherein the hydrogen gas transferred to
the vortex tube comprises pressurized hydrogen gas.
8. The method of claim 1, wherein the catalyst comprises ruthenium,
copper, platinum, palladium, manganese, ferric oxide, silver, a
rare earth metal, or a combination thereof.
9. The method of claim 1, wherein the method is performed at or
below approximately 123 K.
10. The method of claim 1, wherein the catalyst coats the at least
the portion of the interior wall of the vortex tube.
11. The method of claim 1, wherein the hydrogen gas has a first
temperature, wherein the orthohydrogen-rich hydrogen gas has a
second temperature greater than the first temperature, wherein the
parahydrogen-rich hydrogen gas has a third temperature less than
the first temperature.
12. A method comprising: transferring hydrogen gas into a proximal
end of a vortex tube, at least a portion of an interior wall of the
vortex tube comprising a catalyst, wherein the hydrogen gas
comprises orthohydrogen and parahydrogen; flowing the hydrogen gas
toward a distal end of the vortex tube, the hydrogen gas rotating
within the vortex tube as the hydrogen gas flows toward the distal
end; and reacting at least a portion of the hydrogen gas with the
catalyst such that at least a portion of the hydrogen gas converts
to liquid hydrogen.
13. The method of claim 12, wherein the catalyst comprises
ruthenium, copper, platinum, palladium, manganese, ferric oxide,
silver, a rare earth metal, or a combination thereof.
14. The method of claim 12, wherein the liquid hydrogen comprises
more parahydrogen than orthohydrogen by mass.
15. The method of claim 12, further comprising: transferring a
remaining portion of the hydrogen gas out the distal end of the
vortex tube.
16. A device comprising: a vortex tube; an inlet disposed on a
first end of the vortex tube; a catalyst coating at least a portion
of an interior wall of the vortex tube; a first outlet disposed on
a second end of the vortex tube, wherein the first outlet comprises
an opening on the perimeter of the second end of the vortex tube
and a stopper disposed at the center of the second end of the
vortex tube; and a second outlet disposed on the first end of the
vortex tube.
17. The device of claim 16, wherein the catalyst comprises
ruthenium, copper, platinum, palladium, manganese, ferric oxide,
silver, a rare earth metal, or a combination thereof.
18. The device of claim 16, wherein the catalyst comprises a
chemical compound that catalyzes the conversion of parahydrogen to
orthohydrogen.
19. The device of claim 16, further comprising: insulation disposed
around at least a portion of an exterior of the vortex tube.
20. The device of claim 16, further comprising: a plurality of
grooves disposed in the interior wall of the vortex tube.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Appln. No. 62/101,593 filed Jan. 9, 2015, entitled "Device to
Separate and Convert Ortho & Parahydrogen Using a Vortex Tube
with Catalyst," which is incorporated by reference in its
entirety.
BACKGROUND
[0002] Cryogenic refrigeration finds applicability in many fields,
including liquefaction of certain gases, space travel, and fuel
storage, for example. Systems that aid in cryogenic refrigeration
operate at cryogenic temperatures, which can be at or below
-150.degree. C. To reach such temperatures, heat must be removed
from the system in question. Typical refrigeration systems utilize
circulating refrigerants and heat pumps to extract or dissipate
heat from the system. These techniques require a number of moving
parts and are often heavy. Moving parts are more prone to breakage
at cryogenic temperatures due to the increased brittleness at such
low temperatures. Additionally, heavy refrigeration systems have
disadvantages in certain applications, such as space travel, where
weight can negatively impact fuel requirements and limit travel
distance and time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The detailed description is set forth with reference to the
accompanying figures. In the figures, the left-most digit(s) of a
reference number identifies the figure in which the reference
number first appears. The use of the same reference numbers in
different figures indicates similar or identical items or
features.
[0004] FIG. 1 illustrates a perspective view of an example
para-orthohydrogen conversion device.
[0005] FIG. 2 illustrates a cross-sectional side view of an example
para-orthohydrogen conversion device.
[0006] FIG. 3 illustrates a cross-sectional side view of another
example para-orthohydrogen conversion device with flow
indication.
[0007] FIG. 4 illustrates a cross-sectional side view of a further
example para-orthohydrogen conversion device, a portion of which
has been magnified.
[0008] FIG. 5 is a flowchart illustrating an example method by
which a para-orthohydrogen conversion device may operate.
[0009] FIG. 6 is a flowchart illustrating another example method by
which a para-orthohydrogen conversion device may operate.
DETAILED DESCRIPTION
Overview
[0010] This overview, including section titles, is provided to
introduce a selection of concepts in a simplified form that are
further described below. The overview is provided for the reader's
convenience and is not intended to limit the scope of the
implementations or claims, nor the proceeding sections.
[0011] This disclosure describes devices and methods for
para-orthohydrogen conversion.
[0012] As discussed above, cryogenic refrigeration systems operate
at cryogenic temperatures, which can be at or below -150.degree. C.
Typical refrigeration systems utilize circulating refrigerants and
heat pumps, which require a number of moving parts that are prone
to breakage at cryogenic temperatures. Additionally, such
refrigeration systems are heavy, which causes disadvantages in
certain applications such as space travel. Example devices and
methods as described herein alleviate the shortcomings of current
cryogenic refrigeration systems by employing a vortex tube
comprising a catalyst that may convert parahydrogen to
orthohydrogen, which is an endothermic reaction that absorbs heat
from the system. In so doing, the devices described herein may
expel heat from the vortex tube in the form of orthohydrogen-rich
hydrogen gas while maintaining cooled parahydrogen-rich hydrogen
gas without moving parts, liquid refrigerants, or heavy circulating
systems. Furthermore, the para-orthohydrogen conversion devices
described herein may be used to liquefy hydrogen gas.
[0013] Before explaining examples of the devices and methods
described herein, the following information regarding hydrogen gas
and the dynamics of centrifugal geometries may be helpful. Diatomic
molecules of hydrogen (H.sub.2) have two different spin isomers,
orthohydrogen and parahydrogen. In orthohydrogen molecules, the
spins of the two protons are parallel and form a triplet state. In
parahydrogen molecules, the spins of the two protons are
antiparallel and form a singlet state. Due to these differing spin
states, at standard temperature and pressure, hydrogen gas contains
approximately 25% parahydrogen and 75% orthohydrogen. Higher
percentages of orthohydrogen may be achieved by increasing
temperature or otherwise introducing heat to hydrogen gas. This is
primarily due to the increase in entropy caused by the increased
temperature, which causes the hydrogen molecules to reach higher
energy levels which favor orthohydrogen spin states. Higher
percentages of parahydrogen may be achieved by decreasing
temperature or otherwise extracting heat from hydrogen gas. This is
primarily due to the decrease in entropy caused by the decreased
temperature, which causes the hydrogen molecules to reach lower
energy levels which favor the parahydrogen spin state. As such, in
general, orthohydrogen-rich gas will exist at higher temperatures,
while parahydrogen-rich gas will exist at lower temperatures.
[0014] Centrifugal geometries, such as vortex tubes, also known as
Ranque-Hilsch vortex tubes, promote the controlled rotation of gas.
In some applications, compressed air may be rotated within the
vortex tube. As the air rotates, the centrifugal nature of the
vortex tube allows the air located near the periphery of the vortex
tube to move faster than the air located near the core or center of
the vortex tube. Based on the thermodynamic approach to
temperature, at a certain pressure, faster moving air molecules
will have a higher temperature than slower moving molecules. Thus,
in a vortex tube, faster moving air molecules located near the
periphery of the vortex tube will have a higher temperature than
the slower moving air molecules located near the center or core of
the vortex tube. As such, by utilizing a vortex tube, air can be
separated into hot and cold streams.
[0015] Moving now to the device described in the present
disclosure, the device may comprise a vortex tube having a catalyst
on at least a portion of an interior wall of the vortex tube to
assist in the conversion of parahydrogen to orthohydrogen. In some
examples, the catalyst may be disposed on substantially all of an
interior surface of the vortex tube, while in other examples the
catalyst may be disposed over less than all of the interior surface
of the vortex tube. The catalyst may be ruthenium, copper,
platinum, palladium, manganese, ferric oxide, silver, a rare earth
metal, combinations of the foregoing, or any other catalyst that
promotes the conversion of parahydrogen to orthohydrogen. The
device may also comprise an inlet disposed on a first end of the
vortex tube. The inlet may receive hydrogen gas, such as for
example, pressurized hydrogen gas comprising approximately 50%
orthohydrogen and approximately 50% parahydrogen. The device may
also comprise a first outlet disposed on a second end of the vortex
tube. The first outlet may comprise an opening on the perimeter of
the second end of the vortex tube and a stopper disposed at the
center of the second end of the vortex tube. The configuration of
the first outlet may promote the release of hydrogen gas situated
near the perimeter or periphery of the second end of the vortex
tube, while hindering or preventing hydrogen gas situated near the
center or core of the vortex tube from exiting the vortex tube. The
shape of the stopper may also direct the hydrogen gas situated near
the center or core of the vortex tube back toward the first end of
the vortex tube. The device may further comprise a second outlet
disposed on the first end of the vortex tube. The second outlet may
promote the release of the hydrogen gas situated near the center or
core of the vortex tube.
[0016] In some examples, a method of operating the
para-orthohydrogen conversion devices described herein may comprise
transferring hydrogen gas into a proximal end of a vortex tube. At
least a portion of an interior wall of the vortex tube may comprise
a catalyst, such as, for example, ruthenium, copper, platinum,
palladium, manganese, ferric oxide, silver, a rare earth metal,
combinations of the foregoing, or any other catalyst that promotes
the conversion of parahydrogen to orthohydrogen. In some examples,
the hydrogen gas that is transferred into the vortex tube may be
pressurized and may comprise a predetermined amount of parahydrogen
and orthohydrogen at a certain temperature. For example, the
hydrogen gas may be pressurized to approximately 50 psi at
approximately 77 K and comprise approximately 50% parahydrogen and
approximately 50% orthohydrogen. It should be noted that a specific
pressure and temperature is not required and the temperatures and
pressures described herein are for illustration only and are not by
way of limitation. The hydrogen gas may be flowed from the proximal
end of the vortex tube to the distal end of the vortex tube. As the
hydrogen gas flows, the hydrogen gas may rotate within the vortex
tube. The rotating hydrogen gas may contact the inner wall of the
vortex tube, which comprises the catalyst, converting at least a
portion of the parahydrogen to orthohydrogen. The reaction of the
hydrogen gas with the catalyst is endothermic, which absorbs heat
near the internal wall, or periphery, of the vortex tube, and
creates cooler parahydrogen-rich gas that rotates near the center
or core of the vortex tube.
[0017] A first outlet on the distal end of the vortex tube may be
configured to allow the orthohydrogen-rich gas rotating on the
periphery of the vortex tube to exit the vortex tube. The
orthohydrogen-rich gas may have a higher temperature and lower
pressure than the hydrogen gas that was initially transferred into
the vortex tube. For example, the orthohydrogen-rich gas may have a
temperature of approximately 120 K and have a reduced pressure of
approximately 14 psi. The first outlet may also comprise a stopper
or other component that hinders or prevents the parahydrogen-rich
gas near the center or core of the vortex tube from exiting out the
first outlet. The stopper may be shaped to promote the flow of
parahydrogen-rich gas back toward the proximal end of the vortex
tube. In some examples, the centerline of the stopper is ported,
which may promote gas to enter the ported portion of the stopper.
In other examples, the stopper may have a flat end, as opposed to a
pointed end, that may allow the hydrogen gas on the periphery of
the vortex tube exit the tube while creating a stopping point for
the hydrogen gas near the center or core of the vortex tube. The
parahydrogen-rich gas may exit the vortex tube through a second
outlet disposed near the proximal end of the vortex tube. The
parahydrogen-rich gas may have a lower temperature than both the
initial hydrogen gas that was transferred into the vortex tube and
the orthohydrogen-rich gas that rotates near the periphery of the
vortex tube. For example, the parahydrogen-rich gas may have a
temperature of approximately 30 K and may have a pressure similar
to the orthohydrogen-rich gas, such as, for example, approximately
14 psi.
[0018] In some examples, a method of operating the
para-orthohydrogen conversion devices described herein may include
converting hydrogen gas to liquid hydrogen, also known as
liquefaction. For example, hydrogen gas may be transferred into the
proximal end of a vortex tube, at least a portion of the inner wall
of which may comprise a catalyst. The hydrogen gas may be
pressurized and may enter the vortex tube at a first temperature.
In some examples, the hydrogen gas may be pre-cooled, such as by a
liquid nitrogen bath. As the hydrogen gas flows from the proximal
end of the vortex tube to the distal end, the hydrogen gas may
rotate. The rotation may be caused, at least in part, by the
direction of the flow of the hydrogen gas entering the vortex tube.
The parahydrogen in the hydrogen gas may contact the catalyst and
be converted to orthohydrogen, which is an endothermic reaction
that absorbs heat from the system. The orthohydrogen-rich gas may
accumulate near the periphery of the vortex tube at a temperature
higher than the temperature of the initial hydrogen gas, while
parahydrogen-rich gas may accumulate near the center or core of the
vortex tube at a lower temperature than the initial temperature of
the hydrogen gas, resulting in liquefaction of the
parahydrogen-rich gas.
[0019] Para-orthohydrogen conversion devices according to this
disclosure may be designed for a variety of applications, such as,
for example, removal of heat in cryogenic conditions, cooling of
various components of a system, and/or liquefaction of hydrogen
gas.
[0020] One or more examples of the present disclosure are
illustrated in the accompanying drawings. Those of ordinary skill
in the art will understand that the systems and methods
specifically described herein and illustrated in the accompanying
drawings are non-limiting examples and that the scope of these
examples is defined solely by the claims. The features illustrated
or described in connection with one example may be combined with
the features of other examples. For example, the compressor
described in one example may be included in the system comprising
the computing devices. Such modifications and variations are
intended to be included within the scope of the appended
claims.
[0021] Additional details are described below with reference to
several examples.
Example Devices
[0022] FIGS. 1-4 illustrate various examples of para-orthohydrogen
conversion devices. The sizes, shapes, and symbols used to describe
the various components of the devices are used for illustration
only and should not be used as limitations of the devices as
described herein.
[0023] FIG. 1 illustrates a perspective view of an example of a
para-orthohydrogen conversion device 100. Device 100 may comprise a
vortex tube 102. As used herein, the term "vortex tube" means a
cylindrical tube designed to promote the rotation of air within the
tube. The diameter of the vortex tube 102 may vary depending on the
application and desired amount of hydrogen conversion. For example,
a larger-diameter vortex tube 102 may be utilized when conversion
of a large volume of hydrogen gas is desired. The vortex tube 102
may be constructed of various materials, such as, for example,
metal, polymer, or a combination thereof. The vortex tube 102 may
be constructed by a number of methodologies, such as, for example,
three-dimensional printing and/or metal working (e.g., extrusion,
casting, boring, etc.). By way of example, a vortex tube 102 as
used in the manner described herein for para-orthohydrogen
conversion may be constructed from stainless steel, polyvinyl
chloride, or other material sturdy enough to withstand the pressure
differential as between the interior and exterior of the vortex
tube 102. The vortex tube 102 may comprise an inlet 104 disposed on
a first end of the vortex tube 102. The inlet 104 may be positioned
such that gas is transferred into the vortex tube 102 tangentially
or perpendicularly from the flow of gas through the vortex tube
102.
[0024] The vortex tube 102 illustrated in FIG. 1 may also comprise
a first outlet 108 disposed on a second end of the vortex tube 102.
The first outlet 108 may have various shapes and sizes. For
example, the first outlet 108 may have the same or similar diameter
as the vortex tube 102, or the first outlet 108 may have a smaller
diameter than the vortex tube 102. A stopper 106 may be disposed at
or near the center of the second end of the vortex tube 102. The
stopper 106 may be conical shaped, with the point or vertex of the
stopper 106 pointing in toward the vortex tube 102. The stopper 106
may be positioned such that only hydrogen gas located at or near
the periphery of the vortex tube 102 may exit through the first
outlet 108. In some examples, the stopper 106 may be adjustable,
either manually or automatically, such that the stopper 106 may
move axially into or out of the vortex tube 102. When the stopper
106 is adjusted more into the vortex tube 102, the opening between
the stopper 106 and the interior wall of the vortex tube 102 may
decrease. This decreased opening may decrease the air flow through
the first outlet 108 and increase pressure within the vortex tube
102. When the stopper 106 is adjusted away from the vortex tube
102, the opening between the stopper 106 and the interior wall of
the vortex tube 102 may increase. This increased opening may
increase the air flow through the first outlet 108 and decrease
pressure within the vortex tube 102. In some examples, the stopper
106 may include one or more grooves along the centerline of the
stopper 106. The grooves may be received by threading disposed on
the distal end of the vortex tube 102 and hold the stopper 106 in
position.
[0025] Adjustment of the stopper 106 may also aid in more accurate
transferring of orthohydrogen-rich gas from the vortex tube 102.
For example, as described above, orthohydrogen-rich gas may
accumulate at the periphery of the vortex tube 102, while
parahydrogen-rich gas may accumulate at the center or core of the
vortex tube 102. The thickness of the layer of orthohydrogen-rich
gas and the thickness of the layer of parahydrogen-rich gas within
the vortex tube 102 may differ depending on, for example, the
initial concentrations of parahydrogen and orthohydrogen in the
hydrogen gas transferred into the vortex tube 102, the pressure
within the vortex tube 102, and the initial temperature of the
hydrogen gas transferred into the vortex tube 102. As such, the
orthohydrogen-rich periphery portion or layer may be larger in some
applications or configurations than the orthohydrogen-rich
periphery portion or layer in other applications or configurations.
The stopper 106 position may be adjusted to account for such
variances.
[0026] The stopper 106 may also hinder or prevent the
parahydrogen-rich gas at or near the center of the vortex tube from
exiting through the first outlet 108. Instead, the stopper 106 may
promote the parahydrogen-rich gas to flow back toward the first end
of the vortex tube 102. A second outlet 110 may be disposed on the
first end of the vortex tube 102 and may be positioned to accept
the parahydrogen-rich gas flowing toward the first end of the
vortex tube 102. The second outlet 110 may be positioned at or near
the center of the vortex tube 102, where the parahydrogen-rich gas
is flowing.
[0027] FIG. 2 illustrates a cross-sectional side view of an example
of a para-orthohydrogen conversion device 200. The cross-section
shown in FIG. 2 is made at or near the center of device 100 such
that the inlet, first outlet, second outlet, and vortex tube are
essentially split in half. Device 200 may comprise the same or
similar components as device 100. For example, device 200 may
comprise a vortex tube 202, an inlet 204, a first outlet 208, a
second outlet 212, and a stopper 210. Device 200 may also comprise
a catalyst 206 (shown as the shaded portion of FIG. 2). The
catalyst 206 may comprise the material, or a portion thereof, that
the vortex tube 202 is constructed of, and/or the catalyst 206 may
comprise a coating disposed on the interior wall of the vortex tube
202. The catalyst 206 may be disposed on the entire interior wall
of the vortex tube 202, or only a portion (i.e., less than all)
thereof. The catalyst 206 may comprise ruthenium, copper, platinum,
palladium, manganese, ferric oxide, silver, a rare earth metal,
combinations of the foregoing, or any other catalyst that promotes
the conversion of parahydrogen to orthohydrogen.
[0028] Device 200 may also comprise insulation 214, which may
partially or completely cover an outer circumferential surface of
the vortex tube 202. In some examples, the insulation may be
constructed of one or more materials that hinder the exchange of
heat between the interior and exterior of the vortex tube 202. The
insulation 214 may comprise one or more layers, and when comprising
multiple layers, the layers may be made of the same or differing
materials. For example, the insulation 214 may comprise multi-layer
insulation (MLI), silica-aerogel, spray-foam, vacuum, etc.
[0029] FIG. 3 illustrates a cross-sectional side view of an example
para-orthohydrogen conversion device 300 that shows the flow of
hydrogen gas through the device. The cross-section shown in FIG. 3
is made at or near the center of device 100 such that the inlet,
first outlet, second outlet, and vortex tube are essentially split
in half. Device 300 may have the same or similar components as
those shown in FIG. 2. For example, device 300 may comprise a
vortex tube 302, an inlet 304, a catalyst 306, a first outlet 308,
a stopper 310, and a second outlet 312. Directional arrows have
been added to FIG. 3 to show an example flow of hydrogen gas
through device 300. Starting at the inlet 304, hydrogen gas may be
transferred into device 300 from a source, such as, for example, a
pressurized hydrogen gas tank. The hydrogen gas may be pressurized,
such as, for example, to around 50 psi, and may comprise a
predetermined composition of parahydrogen and orthohydrogen, such
as, for example, approximately 50% parahydrogen and approximately
50% orthohydrogen. Again, the temperature, pressure, and
para-orthohydrogen composition described in this example are for
illustration only and are not limiting. The hydrogen gas may travel
through the inlet 304 and into the vortex tube 302. As the hydrogen
gas enters the vortex tube 302, the hydrogen gas may begin to swirl
or otherwise rotate. The rotating hydrogen gas may travel down the
vortex tube 302 toward the first outlet 308. As the rotating
hydrogen gas travels, at least a portion of the hydrogen gas makes
contact with the interior wall of the vortex tube 302.
[0030] The interior wall of the vortex tube 302 may comprise a
catalyst 306, which may convert all or a portion of the
parahydrogen gas that contacts the interior wall into
orthohydrogen, creating a layer of orthohydrogen-rich gas at the
periphery of the vortex tube 302 via an endothermic reaction. The
catalyzed reaction of parahydrogen to orthohydrogen may cause heat
to be absorbed in the orthohydrogen-rich layer, which may cause the
orthohydrogen-rich layer to rotate more quickly. The unreacted
hydrogen gas may accumulate near the center or core of the vortex
tube 302 and may contain more parahydrogen than orthohydrogen. This
parahydrogen-rich layer may have a decreased temperature and rotate
slower than the orthohydrogen-rich layer. When the hydrogen gas
reaches the first outlet 308 of the vortex tube 302, the stopper
310 may allow the orthohydrogen-rich layer near the periphery of
the vortex tube 302 to exit the vortex tube 302, while hindering or
stopping the parahydrogen-rich layer near the center of the vortex
tube 302 from exiting the vortex tube 302. The stopper 310 may
redirect the parahydrogen-rich gas back toward the inlet 304. A
second outlet 312 may be disposed on the end of the vortex tube 302
opposite the first outlet 308. The parahydrogen-rich gas may exit
the vortex tube 302 through the second outlet 312 to a holding
container or an additional vortex tube, for example.
[0031] FIG. 4 illustrates a cross-sectional side view of an example
para-orthohydrogen conversion device 400. Device 400 may have the
same or similar components as those shown in FIG. 2. For example,
device 400 may comprise a vortex tube 402, an inlet 404, a catalyst
406, a first outlet 408, a stopper 410, and a second outlet 412.
Device 400 may also comprise a plurality of grooves 414. The
grooves 414 are depicted in FIG. 4 as being semi-circular in shape,
or otherwise described as scalloped, however, the grooves 414 may
be of various shapes and sizes. The grooves 414 may also be spirals
or channels in the interior surface of the vortex tube 402.
Additionally, each groove 414 may have a uniform shape and size to
other grooves 414, or each groove 414 may vary slightly or
substantially in shape and size to other grooves 414. Furthermore,
the grooves 414 may be indents or etchings in the vortex tube 402
or may be raised up from the surface of the interior wall of the
vortex tube 402. The grooves 414 may increase the surface area of
the catalyst 406 and provide for a larger number of reaction sites
with the parahydrogen as it flows through the vortex tube 402.
[0032] Devices 100-400 may also include controllers and/or sensors
(not illustrated) to monitor and control the pressure, temperature,
and flow of hydrogen gas through the vortex tube, as well as valves
and assemblies to open or close the flow of hydrogen through the
inlet, first outlet, and/or second outlet. Additionally, gauges or
other monitoring devices may be used to monitor pressure,
temperature, flow rate, and hydrogen isomer content within the
vortex tube. For example, para-orthohydrogen composition of vortex
tube effluent may be measured via hot-wire anemometry.
[0033] As described in FIGS. 1-4, various components of devices
100-400 have been described as components of certain examples of
the para-orthohydrogen conversion devices described herein.
However, it should be understood that in some examples each
component described herein may be included in any or all of devices
100-400, and the inclusion of a component in one example does not
exclude its potential inclusion in other examples. Additionally,
multiples of devices 100-400 may be coupled together to form a
system that further promotes cryogenic cooling and liquefaction.
For example, three para-orthohydrogen conversion devices, such as
described herein, may be coupled together. Hydrogen gas may be
transferred to a first conversion device and the resulting
parahydrogen-rich gas may be transferred to a second conversion
device. The parahydrogen-rich gas may undergo further conversion in
the second conversion device such that the resulting parahydrogen
reaches a temperature that allows for liquefaction of the hydrogen
gas. The liquid hydrogen may be transferred from the second
conversion device to a holding tank or other apparatus for storage
or use. The orthohydrogen-rich gas from the first conversion device
may be transferred to a third conversion device. The
orthohydrogen-rich gas may undergo further conversion such that a
portion of the remaining parahydrogen is converted to
orthohydrogen. As such, the para-orthohydrogen conversion devices
disclosed herein may be cascaded to increase cooling and
liquefaction.
[0034] The devices described in FIGS. 1-4 have been shown to
effectively convert parahydrogen to orthohydrogen, which allows for
cryogenic refrigeration and liquefaction without the use of moving
parts or heavy liquid circulation systems. These devices may allow
for the efficient liquefaction of hydrogen, in some cases at or
above 30% efficiency. The use of a catalyst, such as described
herein, may increase the efficiency of cryogenic refrigeration
and/or liquefaction. For example, a 69% difference in temperature
separation between parahydrogen and orthohydrogen was noted in
vortex tubes comprising a catalyst versus bare vortex tubes. Fluid
flow modules, such as COMSOL computational fluid dynamics modeling,
may be used to optimize flow of hydrogen gas and liquid hydrogen
through the vortex tubes as described herein.
[0035] The present disclosure may find use with gases other than
hydrogen. For example, the vortex tube design described herein may
be used with gases such as deuterium (.sup.2D), Tritium (.sup.3H),
Helium (He), and Neon (Ne). The same or substantially the same
design described herein may be used to cool or liquefy the
above-mentioned gases. The same or similar catalysts may be used,
as well as the same or similar pressures, temperatures, and
components of the devices, such as, for example, the vortex tube,
first and second outlet, inlet, and stopper.
Example Methods
[0036] FIGS. 5 and 6 illustrate example methods of operating a
para-orthohydrogen conversion device, such as described herein.
Methods 500 and 600 are illustrated as logical flow graphs. The
order in which the operations or steps are described is not
intended to be construed as a limitation, and any number of the
described operations can be omitted, modified, or combined in any
order and/or in parallel to implement methods 500 and 600. For
example, while FIG. 6 depicts flowing hydrogen gas toward the
distal end of the vortex tube with hydrogen gas rotating within the
vortex tube before the hydrogen gas reacts with the catalyst,
method 600 may comprise reacting the hydrogen gas with the catalyst
before or at the same time as the hydrogen gas rotates within the
vortex tube.
[0037] FIG. 5 illustrates a method 500 of operating a
para-orthohydrogen conversion device. At block 502, method 500 may
comprise transferring hydrogen gas into a proximal end of a vortex
tube. In some examples, the transferred hydrogen gas may be
pressurized, such as, for example, to approximately 50 psi. At
least a portion of an interior wall of the vortex tube may comprise
a catalyst. In some examples, the catalyst may be part or all of
the material that the vortex tube is constructed from. In other
examples, the catalyst may be a coating covering all or a portion
of the interior wall of the vortex tube. The hydrogen gas that is
transferred into the proximal end of the vortex tube may comprise
orthohydrogen and parahydrogen. In some examples, the composition
of the hydrogen gas may be more orthohydrogen than parahydrogen. In
other examples, the composition of the hydrogen gas may be more
parahydrogen than orthohydrogen. In other examples, the composition
of the hydrogen gas may be approximately 50% orthohydrogen and
approximately 50% parahydrogen.
[0038] At block 504, method 500 may comprise flowing the hydrogen
gas toward a distal end of the vortex tube. As the hydrogen gas
flows, the hydrogen gas may rotate within the vortex tube. The
rotating hydrogen gas may create a vortex such that the hydrogen
gas at the exterior or periphery of the vortex tube rotates more
quickly than the hydrogen gas at the center or core of the vortex
tube.
[0039] At block 506, method 500 may comprise reacting hydrogen gas
with the catalyst such that a least a portion of the parahydrogen
is converted to orthohydrogen. In some examples, the catalyst may
be ruthenium, copper, platinum, palladium, manganese, ferric oxide,
silver, a rare earth metal, combinations of the foregoing, or any
other catalyst that promotes the conversion of parahydrogen to
orthohydrogen. As the parahydrogen in the hydrogen gas contacts the
catalyst, the reaction may produce an orthohydrogen-rich layer of
hydrogen gas near the periphery of the vortex tube. The
orthohydrogen-rich layer may have a higher temperature than the
initial hydrogen gas that was transferred into the vortex tube. The
reaction may be endothermic, which causes heat to be absorbed from
the overall system into the orthohydrogen-rich layer. A
parahydrogen-rich layer may accumulate near the center or core of
the vortex tube. The parahydrogen-rich layer may have a lower
temperature than the initial hydrogen gas and the
orthohydrogen-rich layer. In some examples, the orthohydrogen-rich
layer may comprise more orthohydrogen than parahydrogen, such as,
for example, approximately 75% orthohydrogen and approximately 25%
parahydrogen. In some examples, the parahydrogen-rich layer may
comprise more parahydrogen than orthohydrogen, such as, for
example, approximately 25% orthohydrogen and approximately 75%
parahydrogen. Although the orthohydrogen-rich portion of the
hydrogen gas and parahydrogen-rich portion of the hydrogen gas are
described herein as layers, the two portions need not be distinct
or separate. For example, a gradient of parahydrogen to
orthohydrogen may exist in the vortex tube such that at various
locations in the vortex tube, differing ratios may exist. In
general, a greater percentage of orthohydrogen may be present at
the periphery of the vortex tube, while a greater percentage of
parahydrogen may be present at the center of the vortex tube. By
way of further example, a velocity gradient may exist in the vortex
tube such that gas rotating at the periphery of the vortex tube may
rotate more quickly than gas rotating at the center of the vortex
tube. The gas between the center and periphery may rotate at some
speed between the speed of rotation at the center and the speed of
rotation at the periphery.
[0040] At block 508, method 500 may comprise expelling the
orthohydrogen-rich gas located at or near the periphery of the
vortex tube out of the distal end of the vortex tube. The distal
end of the vortex tube may comprise an outlet with a stopper, which
may be adjustable. The stopper may have a conical shape, which may
allow the orthohydrogen-rich gas located at or near the periphery
of the vortex tube to exit the vortex tube while hindering or
stopping the parahydrogen-rich gas located at or near the center of
the vortex tube from exiting the vortex tube. The
orthohydrogen-rich gas may exit the vortex tube at a temperature
greater than the temperature of the initial hydrogen gas that was
transferred into the vortex tube.
[0041] At block 510, method 500 may comprise flowing the
parahydrogen-rich gas located at or near the center or core of the
vortex tube toward the proximal end of the vortex tube. The
parahydrogen-rich gas may rotate near the center of the vortex tube
as it flows from the distal end to the proximal end. An outlet
disposed at or near the proximal end of the vortex tube may receive
the parahydrogen-rich gas and allow the parahydrogen-rich gas to
exit the vortex tube. The parahydrogen-rich gas may exit the vortex
tube at a temperature less than the temperature of the initial
hydrogen gas and the orthohydrogen-rich gas.
[0042] All or a portion of the operations of method 500 may be
performed at cryogenic temperatures, such as those found in space.
The operation of method 500 may result in a cooled amount of
parahydrogen-rich gas, which may be used to refrigerate a variety
of containers and substances. For example, the parahydrogen-rich
gas may reach 30K (-243.degree. C.) or less. Liquid oxygen, a
commonly used rocket propellant, has a freezing point of
approximately 54K and a boiling point at approximately 90K. As
such, the parahydrogen-rich gas may be utilized to maintain liquid
oxygen in a frozen or liquid state during space travel until the
liquid oxygen is needed for propulsion. By way of further example,
liquid hydrogen is also a commonly used rocket propellant. Liquid
hydrogen, however, has a tendency to "boil-off" or otherwise
vaporize from ambient heat surrounding the vessel holding the
liquid hydrogen. Method 500 may be utilized to direct the vaporized
hydrogen gas toward a vortex tube to start the para-orthohydrogen
conversion process. Method 500 may result in at least a portion of
the vaporized hydrogen gas being cooled back to a liquid state. The
re-liquefied hydrogen may be reintroduced to the liquid hydrogen
holding tank, thus diminishing the adverse effects of "boil-off"
Liquefaction is described in more detail below with respect to
method 600.
[0043] FIG. 6 illustrates a method 600, which may include the same,
different, or additional operations as method 500. At block 602,
method 600 may comprise transferring hydrogen gas into a proximal
end of a vortex tube. In some examples, the transferred hydrogen
gas may be pressurized, such as, for example, to approximately 50
psi. At least a portion of an interior wall of the vortex tube may
comprise a catalyst. In some examples, the catalyst may be part or
all of the material that the vortex tube is constructed from. In
other examples, the catalyst may be a coating covering all or a
portion of the interior wall of the vortex tube. The hydrogen gas
that is transferred into the proximal end of the vortex tube may
comprise orthohydrogen and parahydrogen. In some examples, the
composition of the hydrogen gas may be more orthohydrogen than
parahydrogen. In other examples, the composition of the hydrogen
gas may be more parahydrogen than orthohydrogen. In other examples,
the composition of the hydrogen gas may be approximately 50%
orthohydrogen and approximately 50% parahydrogen.
[0044] At block 604, method 600 may comprise flowing the hydrogen
gas toward a distal end of the vortex tube. As the hydrogen gas
flows, the hydrogen gas may rotate within the vortex tube. The
rotating hydrogen gas may create a vortex such that the hydrogen
gas at the exterior or periphery of the vortex tube rotates more
quickly than the hydrogen gas at the center or core of the vortex
tube.
[0045] At block 606, method 600 may comprise reacting at least a
portion of the hydrogen gas with the catalyst such that at least a
portion of the hydrogen gas converts to liquid hydrogen. In some
examples, at least a portion of the parahydrogen in the hydrogen
gas may contact the catalyst and be converted to orthohydrogen,
causing an orthohydrogen-rich layer of hydrogen gas at or near the
periphery of the vortex tube. Slower moving, parahydrogen-rich gas
may accumulate at or near the center of the vortex tube. The
temperature of the parahydrogen-rich gas may decrease to at or
below the boiling point of hydrogen, which may result in all or a
portion of the hydrogen gas changing to a liquid state. The vortex
tube may be positioned such that as liquid hydrogen is formed,
gravity may cause the liquid hydrogen to exit the vortex tube, such
as through an outlet near the proximal end of the vortex tube. In
some examples, such as in space travel application, little or no
gravitational pull may be present. In these examples, a stopper,
which may be conical shaped, may be disposed at or near the distal
end of the vortex tube. The stopper may redirect the
parahydrogen-rich gas near the center of the vortex tube back
toward the proximal end of the vortex tube, which may comprise an
outlet through which the liquid hydrogen may exit the vortex tube.
The liquid hydrogen produced at or near the center of the vortex
tube may comprise more parahydrogen than orthohydrogen, and in some
examples, the liquid hydrogen may comprise all parahydrogen.
[0046] At block 608, method 600 may comprise transferring a
remaining portion of the hydrogen gas out the distal end of the
vortex tube. The remaining portion of the hydrogen gas may comprise
more orthohydrogen than parahydrogen and may exit the vortex tube
at a temperature greater than the initial hydrogen gas transferred
into the vortex tube and the parahydrogen-rich gas and liquid
hydrogen located at or near the center of the vortex tube. In some
applications, such as space travel, the orthohydrogen-rich gas that
exits the vortex tube may be used for heating applications, such
as, for example, air conditioning of a living environment and
heating of water or other liquids. The orthohydrogen-rich gas may
also be cooled, such as by exposing the gas to temperatures found
in space, which may convert all or a portion of the orthohydrogen
back to parahydrogen. The hydrogen gas may then be reintroduced
into the vortex tube for further cryogenic refrigeration or
liquefaction purposes.
[0047] The term "about" or "approximate" as used in the context of
describing a range of volume, pressure, or temperature is to be
construed to include a reasonable margin of error that would be
acceptable and/or known in the art.
[0048] The present description uses specific numerical values to
quantify certain parameters relating to the innovation, where the
specific numerical values are not expressly part of a numerical
range. It should be understood that each specific numerical value
provided herein is to be construed as providing literal support for
a broad, intermediate, and narrow range. The broad range associated
with each specific numerical value is the numerical value plus and
minus 60 percent of the numerical value, rounded to two significant
digits. The intermediate range associated with each specific
numerical value is the numerical value plus and minus 30 percent of
the numerical value, rounded to two significant digits. The narrow
range associated with each specific numerical value is the
numerical value plus and minus 15 percent of the numerical value,
rounded to two significant digits. These broad, intermediate, and
narrow numerical ranges should be applied not only to the specific
values, but should also be applied to differences between these
specific values.
[0049] Furthermore, this disclosure provides various example
implementations, as described and as illustrated in the figures.
However, this disclosure is not limited to the examples described
and illustrated herein, but can extend to other examples, as would
be known or as would become known to those skilled in the art.
Reference in the specification to "one example," "this example,"
"these examples," or "some examples" means that a particular
feature, structure, or characteristic described is included in at
least one example, and the appearances of these phrases in various
places in the specification are not necessarily all referring to
the same example.
CONCLUSION
[0050] Although the disclosure describes examples having specific
structural features and/or methodological acts, it is to be
understood that the claims are not necessarily limited to the
specific features or acts described. Rather, the specific features
and acts are merely illustrative of some examples that fall within
the scope of the claims of the disclosure.
* * * * *