U.S. patent application number 10/938904 was filed with the patent office on 2006-03-02 for method of assembling multiple port assemblies in a spherical cavitation chamber.
This patent application is currently assigned to Impulse Devices, Inc.. Invention is credited to Dario Felipe Gaitan, Daniel A. Phillips, Ross Alan Tessien.
Application Number | 20060042087 10/938904 |
Document ID | / |
Family ID | 35940952 |
Filed Date | 2006-03-02 |
United States Patent
Application |
20060042087 |
Kind Code |
A1 |
Tessien; Ross Alan ; et
al. |
March 2, 2006 |
Method of assembling multiple port assemblies in a spherical
cavitation chamber
Abstract
A method of assembling multiple port assemblies in a single
cavitation chamber, typically a spherical chamber, is provided. The
method is comprised of the steps of boring a first cone-shaped port
in a cavitation chamber wall of one piece of the cavitation
chamber; locating a mounting ring with a cone-shaped external
surface corresponding to the first cone-shaped port within the
cavitation chamber prior to assembling the multiple pieces that
comprise the cavitation chamber; assembling the multiple cavitation
chamber pieces together to form the cavitation chamber; boring a
second, smaller cone-shaped port in the cavitation chamber wall;
inserting a first cone-shaped member corresponding to the second,
smaller cone-shaped port into the cavitation chamber through the
first, larger cone-shaped port; positioning the first cone-shaped
member in the second, smaller cone-shaped port; inserting a second
cone-shaped member corresponding to the internal cone-shaped
surface of the mounting ring through the first, larger cone-shaped
port; positioning the mounting ring within the first, larger
cone-shaped port; and positioning the second member into the
mounting ring. The second, smaller cone-shaped port can be bored
before or after cavitation chamber assembly. The smallest diameter
of the first port is larger than the largest diameter of either
member, thus insuring that the members can be inserted into the
cavitation chamber through the port. The first and second members
can be windows, plugs, gas feed-throughs, liquid feed-throughs,
mechanical feed-throughs, sensors, sensor couplers, or transducer
couplers. To aid the assembly process, specialized tools can be
used to position the first and second members.
Inventors: |
Tessien; Ross Alan; (Nevada
City, CA) ; Gaitan; Dario Felipe; (Nevada City,
CA) ; Phillips; Daniel A.; (Grass Valley,
CA) |
Correspondence
Address: |
PATENT LAW OFFICE OF DAVID G. BECK
P. O. BOX 1146
MILL VALLEY
CA
94942
US
|
Assignee: |
Impulse Devices, Inc.
Grass Valley
CA
|
Family ID: |
35940952 |
Appl. No.: |
10/938904 |
Filed: |
September 9, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10926602 |
Aug 25, 2004 |
|
|
|
10938904 |
Sep 9, 2004 |
|
|
|
Current U.S.
Class: |
29/890.09 ;
29/428 |
Current CPC
Class: |
Y10T 29/494 20150115;
Y10T 29/49826 20150115; Y10T 29/49872 20150115; B21D 51/16
20130101 |
Class at
Publication: |
029/890.09 ;
029/428 |
International
Class: |
B21D 51/16 20060101
B21D051/16 |
Claims
1. A method of assembling at least two port assemblies in a
cavitation chamber, the method comprising the steps of: boring a
first cone-shaped port in a cavitation chamber wall of a first
cavitation chamber piece of the cavitation chamber, wherein the
cavitation chamber is comprised of multiple cavitation chamber
pieces including said first cavitation chamber piece, wherein an
external port diameter of said first port and associated with a
cavitation chamber external surface is smaller than an internal
port diameter of said first port and associated with a cavitation
chamber internal surface; locating a mounting ring with a
cone-shaped external surface corresponding to said first
cone-shaped port within said multiple cavitation chamber pieces,
said mounting ring having an internal cone-shaped surface defined
by a first diameter associated with said cavitation chamber
internal surface and a second diameter associated with said
cavitation chamber external surface, wherein said second diameter
is smaller than said first diameter; joining said multiple
cavitation chamber pieces together to form the cavitation chamber,
wherein said mounting ring is located within said cavitation
chamber prior to completion of said joining step; boring a second
cone-shaped port in said cavitation chamber wall of the cavitation
chamber, wherein an external port diameter of said second port and
associated with said cavitation chamber external surface is smaller
than an internal port diameter of said second port and associated
with said cavitation chamber internal surface; inserting a first
member with a cone-shaped external surface corresponding to said
second cone-shaped port through said first cone-shaped port into
said cavitation chamber, wherein said first member is defined by a
third diameter associated with said cavitation chamber internal
surface and a fourth diameter associated with said cavitation
chamber external surface, wherein said fourth diameter is smaller
than said third diameter, and wherein said third diameter is
smaller than said external port diameter of said first port and
larger than said external port diameter of said second port;
positioning said first member in said second port; inserting a
second member with a cone-shaped external surface corresponding to
said internal cone-shaped surface of said mounting ring through
said first cone-shaped port into said cavitation chamber, said
cone-shaped external surface of said second member defined by a
fifth diameter corresponding to said cavitation chamber internal
surface and a sixth diameter corresponding to said cavitation
chamber external surface, and wherein said fifth diameter is
smaller than said external port diameter of said first port;
positioning said mounting ring in said first cone-shaped port; and
positioning said second member in said mounting ring.
2. The method of claim 1, wherein said step of boring said second
cone-shaped port is performed prior to said joining step.
3. The method of claim 1, further comprising the step of attaching
a removable tool to an external chamber surface of said first
member prior to said step of inserting said first member through
said first cone-shaped port.
4. The method of claim 1, further comprising the steps of bonding a
first tool to an external chamber surface of said first member and
temporarily attaching a second tool to said first tool for use in
said first member inserting step, wherein said bonding and
attaching steps are performed prior to said step of inserting said
first member through said first cone-shaped port.
5. The method of claim 4, wherein said bonding step is performed
with a removable adhesive.
6. The method of claim 1, further comprising the steps of: bonding
a first tool to an external chamber surface of said first member;
temporarily attaching a second tool to said first tool for use in
said first member inserting step; temporarily attaching a third
tool to said first tool for use in said first member positioning
step; and detaching said second tool from said first tool prior to
performing said first member positioning step.
7. The method of claim 6, wherein said bonding step is performed
with a removable adhesive.
8. The method of claim 6, further comprising the steps of:
detaching said third tool from said first tool; and detaching said
first tool from said external chamber surface of said first
member.
9. The method of claim 6, further comprising the step of applying
an adhesive to at least a portion of said cone-shaped external
surface of said first member, said applying step performed prior to
said first member inserting step.
10. The method of claim 1, further comprising the steps of: bonding
a first tool to an external chamber surface of said second member
prior to said second member inserting step; and temporarily
attaching a second tool to said first tool for use in said second
member positioning step.
11. The method of claim 10, wherein said bonding step is performed
with a removable adhesive.
12. The method of claim 1, further comprising the step of selecting
said first member from the group consisting of a window, a gas
feed-thru, a liquid feed-thru, a mechanical feed-thru, a sensor, a
sensor coupler, a transducer coupler, or a plug.
13. The method of claim 1, further comprising the step of selecting
said second member from the group consisting of a window, a gas
feed-thru, a liquid feed-thru, a mechanical feed-thru, a sensor, a
sensor coupler, a transducer coupler, or a plug.
14. The method of claim 1, further comprising the step of coupling
a retaining ring to said mounting ring, wherein said retaining ring
is external to said cavitation chamber.
15. The method of claim 1, further comprising the step of coupling
a retaining plate to said first member, wherein said retaining
plate is external to said cavitation chamber.
16. The method of claim 1, further comprising the step of coupling
a retaining plate to said second member, wherein said retaining
plate is external to said cavitation chamber.
17. The method of claim 1, further comprising the step of
interposing a malleable material between said second member and
said mounting ring prior to said step of positioning said second
member in said mounting ring.
18. The method of claim 17, further comprising the step of
selecting a metal for said malleable material.
19. The method of claim 17, further comprising the step of
selecting brass as said malleable material.
20. The method of claim 1, further comprising the step of
interposing a malleable material between said mounting ring and
said first cone-shaped port prior to said step of positioning said
mounting ring in said first cone-shaped port.
21. The method of claim 20, further comprising the step of
selecting a metal for said malleable material.
22. The method of claim 20, further comprising the step of
selecting brass as said malleable material.
23. The method of claim 1, further comprising the step of
interposing a malleable material between said first member and said
second cone-shaped port prior to said step of positioning said
first member in said second cone-shaped port.
24. The method of claim 23, further comprising the step of
selecting a metal for said malleable material.
25. The method of claim 23, further comprising the step of
selecting brass as said malleable material.
26. The method of claim 1, further comprising the step of
interposing at least one o-ring between said second member and said
mounting ring prior to said step of positioning said second member
in said mounting ring.
27. The method of claim 1, further comprising the step of
interposing at least one o-ring between said mounting ring and said
first cone-shaped port prior to said step of positioning said
mounting ring in said first cone-shaped port.
28. The method of claim 1, further comprising the step of
interposing at least one o-ring between said first member and said
second cone-shaped port prior to said step of positioning said
first member in said second cone-shaped port.
29. The method of claim 1, further comprising the step of
interposing a sealant between said second member and said mounting
ring prior to said step of positioning said second member in said
mounting ring.
30. The method of claim 1, further comprising the step of
interposing a sealant between said mounting ring and said first
cone-shaped port prior to said step of positioning said mounting
ring in said first cone-shaped port.
31. The method of claim 1, further comprising the step of
interposing a sealant between said first member and said second
cone-shaped port prior to said step of positioning said first
member in said second cone-shaped port.
32. The method of claim 1, further comprising the step of
interposing an adhesive between said second member and said
mounting ring prior to said step of positioning said second member
in said mounting ring.
33. The method of claim 1, further comprising the step of
interposing an adhesive between said mounting ring and said first
cone-shaped port prior to said step of positioning said mounting
ring in said first cone-shaped port.
34. The method of claim 1, further comprising the step of
interposing an adhesive between said first member and said second
cone-shaped port prior to said step of positioning said first
member in said second cone-shaped port.
35. The method of claim 1, wherein the joining step uses a brazing
procedure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/926,602, filed Aug. 25, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates generally to sonoluminescence
and, more particularly, to a method of constructing a port assembly
in a sonoluminescence cavitation chamber.
BACKGROUND OF THE INVENTION
[0003] Sonoluminescence is a well-known phenomena discovered in the
1930's in which light is generated when a liquid is cavitated.
Although a variety of techniques for cavitating the liquid are
known (e.g., spark discharge, laser pulse, flowing the liquid
through a Venturi tube), one of the most common techniques is
through the application of high intensity sound waves.
[0004] In essence, the cavitation process consists of three stages;
bubble formation, growth and subsequent collapse. The bubble or
bubbles cavitated during this process absorb the applied energy,
for example sound energy, and then release the energy in the form
of light emission during an extremely brief period of time. The
intensity of the generated light depends on a variety of factors
including the physical properties of the liquid (e.g., density,
surface tension, vapor pressure, chemical structure, temperature,
hydrostatic pressure, etc.) and the applied energy (e.g., sound
wave amplitude, sound wave frequency, etc.).
[0005] Although it is generally recognized that during the collapse
of a cavitating bubble extremely high temperature plasmas are
developed, leading to the observed sonoluminescence effect, many
aspects of the phenomena have not yet been characterized. As such,
the phenomena is at the heart of a considerable amount of research
as scientists attempt to not only completely characterize the
phenomena (e.g., effects of pressure on the cavitating medium), but
also its many applications (e.g., sonochemistry, chemical
detoxification, ultrasonic cleaning, etc.).
[0006] In order to study the sonoluminescence phenomena, it is
clearly important to be able to closely monitor the cavitating
bubbles as well as the intensity, frequency and timing of the
resultant sonoluminescence. Additionally, some research may require
probing the cavitating liquid. Lastly, many cavitation experiments
utilize external means of introducing the bubbles into the liquid,
for example bubble tubes or hot wires, thus requiring further means
of entering the cavitating medium.
[0007] Although access to the liquid within a cavitation chamber is
typically required before, during and after a cavitation
experiment, typically this does not present a problem as most
cavitation research is performed at relatively low pressure. As
such, glass or other transparent material is generally used for the
chamber, thus providing an easy means of monitoring on-going
experiments. Additionally, such experiments often use standard
beakers or flasks as the cavitation chamber, allowing convenient
access to the cavitation medium.
[0008] U.S. Pat. No. 4,333,796 discloses a cavitation chamber that
is generally cylindrical although the inventors note that other
shapes, such as spherical, can also be used. As disclosed, the
chamber is comprised of a refractory metal such as tungsten,
titanium, molybdenum, rhenium or some alloy thereof and the
cavitation medium is a liquid metal such as lithium or an alloy
thereof. Surrounding the cavitation chamber is a housing which is
purportedly used as a neutron and tritium shield. Projecting
through both the outer housing and the cavitation chamber walls are
a number of acoustic horns. The specification only discloses that
the horns, through the use of flanges, are secured to the
chamber/housing walls in such a way as to provide a seal.
Similarly, although the specification discloses the use of a tube
to distribute H-isotopes into the host material during cavitation,
the specification does not disclose how the tube is to be sealed as
it passes through the chamber/housing walls. Similarly U.S. Pat.
No. 4,563,341, a continuation-in-part of U.S. Pat. No. 4,333,796,
does not disclose means for the inclusion of a port with the
disclosed cylindrical chamber.
[0009] U.S. Pat. No. 5,659,173 discloses a sonoluminescence system
that uses a transparent spherical flask. The spherical flask is not
described in detail, although the specification discloses that
flasks of Pyrex.RTM., Kontes.RTM., and glass were used with sizes
ranging from 10 milliliters to 5 liters. As the disclosed flask is
transparent, the PMT used to monitor the sonoluminescence was
external to the chamber. The drivers as well as a microphone
piezoelectric were epoxied to the exterior surface of the chamber.
The use of a transparent chamber also allowed the use of an
external light source, e.g., a laser, to determine bubble radius
without requiring the inclusion of a window in the chamber
walls.
[0010] U.S. Pat. No. 5,858,104 discloses a shock wave chamber
partially filled with a liquid. The remaining portion of the
chamber is filled with gas which can be pressurized by a connected
pressure source. Acoustic transducers are used to position an
object within the chamber. Another transducer delivers a
compressional acoustic shock wave into the liquid. A flexible
membrane separating the liquid from the gas reflects the
compressional shock wave as a dilation wave focused on the location
of the object about which a bubble is formed. The patent simply
discloses that the transducers are mounted in the chamber walls
without stating how the transducers are to be mounted. Similarly,
there is no discussion of mounting ports (e.g., view ports) within
the chamber walls.
[0011] U.S. Pat. No. 6,361,747 discloses an acoustic cavitation
reactor in which the reactor chamber is comprised of a flexible
tube. The liquid to be treated circulates through the tube.
Electroacoustic transducers are radially distributed around the
tube, apparently coupled to the flexible tube by being pressed
against the exterior surface of the tube. The heads of the
transducers have the same curvature as the tube, thus helping to
couple the acoustic energy. A film of lubricant interposed between
the transducer heads and the wall of the tube further aid the
coupling of the acoustic energy to the tube.
[0012] Although not in the field of sonoluminescence, U.S. Pat. No.
4,448,743 discloses a confinement chamber for use with an
ultra-high temperature steady-state plasma. The specification
refers to the plasma as a plasmasphere but is unclear as to whether
the confinement chamber is spherical or cylindrical in nature. The
disclosed chamber includes multiple transparent ports, for example
made of germanium or sodium chloride, but does not disclose how the
ports are fabricated or installed within the chamber.
[0013] One approach to fabricating a high pressure spherical
cavitation chamber is disclosed in co-pending patent application
Ser. No. 10/925,070, filed Aug. 23, 2004, entitled Method of
Fabricating a Spherical Cavitation Chamber. In order to provide
optimum high pressure performance, in addition to being spherically
shaped, the inside spherical surface has only a very minor
fabrication seam. Such a chamber, however, provides a challenge as
to port mounting, especially if the smooth inside surface and the
high pressure aspects of the chamber are to be maintained.
[0014] Accordingly, what is needed is a means of including one or
more ports in a high pressure spherical chamber. The present
invention provides a method of constructing such a port
assembly.
SUMMARY OF THE INVENTION
[0015] The present invention provides a method of assembling
multiple port assemblies in a single cavitation chamber, typically
a spherical chamber. The method is comprised of the steps of boring
a first cone-shaped port in a cavitation chamber wall of one piece
of the cavitation chamber; locating a mounting ring with a
cone-shaped external surface corresponding to the first cone-shaped
port within the cavitation chamber prior to assembling the multiple
pieces that comprise the cavitation chamber; assembling the
multiple cavitation chamber pieces together to form the cavitation
chamber; boring a second, smaller cone-shaped port in the
cavitation chamber wall; inserting a first cone-shaped member
corresponding to the second, smaller cone-shaped port into the
cavitation chamber through the first, larger cone-shaped port;
positioning the first cone-shaped member in the second, smaller
cone-shaped port; inserting a second cone-shaped member
corresponding to the internal cone-shaped surface of the mounting
ring through the first, larger cone-shaped port; positioning the
mounting ring within the first, larger cone-shaped port; and
positioning the second member into the mounting ring. The second,
smaller cone-shaped port can be bored before or after cavitation
chamber assembly. The smallest diameter of the first port is larger
than the largest diameter of either member, thus insuring that the
members can be inserted into the cavitation chamber through the
port. The first and second members can be windows, plugs, gas
feed-throughs, liquid feed-throughs, mechanical feed-throughs,
sensors, sensor couplers, or transducer couplers. To aid the
assembly process, specialized tools can be used to position the
first and second members.
[0016] In at least one embodiment, an external ring or plate is
coupled to the mounting ring and/or first member and/or second
member.
[0017] In at least one embodiment a malleable material, preferably
of a metal, and more preferably of brass, is interposed between the
internal cone-shaped surface of the mounting ring and the external
cone-shaped surface of the second member. In at least one
embodiment a malleable material, preferably of a metal, and more
preferably of brass, is interposed between the first, larger
cone-shaped port and the external cone-shaped surface of the
mounting ring. In at least one embodiment a malleable material,
preferably of a metal, and more preferably of brass, is interposed
between the first member and the smaller, cone-shaped port.
[0018] In at least one embodiment a sealant and/or an adhesive is
interposed between the internal cone-shaped surface of the mounting
ring and the external cone-shaped surface of the second member. In
at least one embodiment a sealant and/or an adhesive is interposed
between the first, larger cone-shaped port and the external
cone-shaped surface of the mounting ring. In at least one
embodiment a sealant and/or an adhesive is interposed between the
first member and the smaller, cone-shaped port.
[0019] In at least one embodiment one or more o-rings are
interposed between the internal cone-shaped surface of the mounting
ring and the external cone-shaped surface of the second member. In
at least one embodiment one or more o-rings are interposed between
the first, larger cone-shaped port and the external cone-shaped
surface of the mounting ring. In at least one embodiment one or
more o-rings are interposed between the first member and the
smaller, cone-shaped port.
[0020] A further understanding of the nature and advantages of the
present invention may be realized by reference to the remaining
portions of the specification and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is an illustration of a spherical sonoluminescence
cavitation chamber without ports in accordance with the prior
art;
[0022] FIG. 2 is a cross-sectional view of the spherical cavitation
chamber shown in FIG. 1;
[0023] FIG. 3 is a cross-sectional view of a port assembly,
including a window, in accordance with the prior art;
[0024] FIG. 4 is a cross-sectional view of a cone-shaped port;
[0025] FIG. 5 is a cross-sectional view of a cone-shaped window or
plug within the port of FIG. 4;
[0026] FIG. 6 is a cross-sectional view of a cone-shaped port in
which the configuration of the port is reversed from the port shown
in FIG. 4;
[0027] FIG. 7 is a cross-sectional view of a port assembly that
includes a cone-shaped port, a cone-shaped mounting ring and a
cone-shaped member;
[0028] FIG. 8 is a cross-sectional view of the port assembly of
FIG. 7 assembled;
[0029] FIG. 9 is an illustration of a tool used to pull the
mounting ring into place;
[0030] FIG. 10 is an illustration of the tool shown in FIG. 9 in
which the ring holding members are compressed;
[0031] FIG. 11 is an illustration of the tool shown in FIG. 9 in
which the ring holding members are expanded in order to capture the
mounting ring;
[0032] FIG. 12 is an illustration of a tool used to pull a window
into place;
[0033] FIG. 13 is a cross-sectional view of an alternate tool used
to pull a window into place;
[0034] FIG. 14 is an illustration of a window with a temporary loop
attached;
[0035] FIG. 15 is a cross-sectional view of a port assembly in
which the inner surfaces of the mounting ring and member are curved
to correspond to the curvature of the internal surface of the
cavitation chamber;
[0036] FIG. 16 is a cross-sectional view of a port assembly with an
external retaining ring;
[0037] FIG. 17 is a cross-sectional view of a port assembly with an
alternate external retaining ring;
[0038] FIG. 18 is a cross-sectional view of a port assembly with an
alternate external retaining ring;
[0039] FIG. 19 is a cross-sectional view of a port assembly with an
alternate external retaining ring;
[0040] FIG. 20 is a frontal view of the port assembly shown in FIG.
16;
[0041] FIG. 21 is a cross-sectional view of a port assembly with an
external retaining plate;
[0042] FIG. 22 is a frontal view of the port assembly shown in FIG.
21;
[0043] FIG. 23 is a cross-sectional view of a port assembly such as
the assembly of FIG. 6 with an external retaining plate;
[0044] FIG. 24 is a cross-sectional view of a port assembly with
o-rings used with the mounting ring;
[0045] FIG. 25 is a cross-sectional view of a port assembly with
o-rings used with the central member; and
[0046] FIG. 26 is a graph of measured sonoluminescence data taken
with a sphere fabricated in accordance with the invention.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0047] FIG. 1 is an illustration of a spherical sonoluminescence
cavitation chamber 101, hereafter referred to as simply a
cavitation chamber, according to the prior art. Transducers 109-112
are mounted to the lower hemisphere of chamber 101 and transducers
115-116 are mounted to the upper hemisphere of chamber 101.
[0048] FIG. 2 is a cross-sectional view of spherical cavitation
chamber 101. Chamber 101 has an outer spherical surface 103
defining the outer diameter of the chamber, and an inner spherical
surface 105 defining the inner diameter of the chamber.
[0049] Chamber 101 can be fabricated from any of a variety of
materials, depending primarily on the desired operating temperature
and pressure, as well as the fabrication techniques used to make
the chamber. Typically the chamber is fabricated from a metal;
either a pure metal or an alloy such as stainless steel.
[0050] With respect to the dimensions of the chamber, both inner
and outer diameters, the selected sizes depend upon the intended
use of the chamber. For example, smaller chambers are typically
preferable for situations in which the applied energy (e.g.,
acoustic energy) is somewhat limited. Similarly, thick chamber
walls are preferable if the chamber is to be operated at high
static pressures. For example, the prior art discloses wall
thicknesses of 0.25 inches, 0.5 inches, 0.75 inches, 1.5 inches,
2.375 inches, 3.5 inches and 4 inches, and outside diameters in the
range of 2-10 inches.
[0051] It will be appreciated that the present invention is not
limited to a particular outside chamber diameter, inside chamber
diameter, chamber material, chamber shape, transducer type,
transducer number, or transducer mounting location. Such
information, as provided herein, is only meant to provide exemplary
chamber configurations for which the present invention is
applicable.
[0052] FIG. 3 is a cross-sectional view of a window and port
assembly in accordance with the prior art. For ease of
illustration, only a portion of wall 301 of a spherical chamber
such as the one provided in FIG. 2 is shown in the following
figures. A port 303 has been bored through wall 301. In the
illustrated embodiment, port 303 is used as an observation port,
thus requiring a window 305 to be placed over the port. Window 305
is attached using a standard window mounting flange 307, the flange
being held to wall 301 with multiple bolts 309. Typically a window
sealing member, not shown, is included in this configuration to
insure a gas tight assembly.
[0053] The prior art means of providing a port, as well as the
prior art means of attaching a window or other member to the port,
suffers from several problems. First, the edge 311 of the port
presents a significant discontinuity along surface 313 of wall 301,
the discontinuity effecting the cavitation process. Second, for
high pressure systems the window of this port assembly is prone to
failure as there is minimal contact area between window 305 and
wall 301 (i.e., area 315) and minimal contact area between window
305 and flange 307 (i.e., area 317). Third, it is difficult to
achieve an adequate seal between the window (or similar port
member) and wall 301.
[0054] One approach to alleviating at least some of the issues of
the prior art port assembly is illustrated in FIGS. 4 and 5. As
shown, the port 401 bored into chamber wall 301 includes slanted
surfaces 403, thus providing a cone-shaped port. A similarly shaped
window (or plug) 501 fits within port 401, held in place with
retaining ring 503. Retaining ring 503 is mounted to chamber wall
301 with a plurality of bolts 505.
[0055] One benefit of the assembly shown in FIG. 5 is that the
window is much thicker, thus making it less prone to breakage or
gas leaks. Additionally the discontinuity at region 507 is greatly
reduced as the window can be made thick enough so that the interior
surface 509 of window 501 is in line with interior chamber surface
313. If desired, window surface 509 can even be fabricated with the
same curvature as the interior chamber surface, thus minimizing
internal chamber variations.
[0056] Although the assembly shown in FIGS. 4 and 5 is an
improvement over the prior art port assembly, especially when used
with an evacuated chamber, when used with a high pressure system it
still applies stress to the window (or port plug) in a relatively
small region 511. This is because the shape of member 501 does not
provide any sealing or holding mechanism. Unless a strong bonding
material is provided at the interface between member 501 and port
401, only retaining ring 503 holds member 501 in place. Accordingly
this places a great amount of stress in a very small area, thus
leading to frequent window breakage when used at high pressure.
[0057] FIG. 6 illustrates an alternate embodiment of the invention
useful with high internal pressure chambers. In this embodiment
port 601 is again cone-shaped. Unlike the previous embodiment,
however, the direction of port 601 is reversed so that the small
diameter of the port is located on the outer surface of chamber
wall 301. Assuming a window (or plug) 603, it will be appreciated
that the pressure within the chamber would push member 603 outward,
thus providing not only an improved seal, but more importantly a
means of distributing the force over a much larger region than in
the port assemblies shown in FIGS. 3 and 5. As a result, member 603
is less likely to crack or break during use.
[0058] Although the embodiment shown in FIG. 6 has an improved
resistance to stress-induced breakage, the inventor has found this
embodiment to be problematic as member 603 cannot be replaced once
the cavitation chamber is fabricated. Thus either the chamber must
be capable of being disassembled/reassembled or member 603 must be
located within the chamber prior to completion. The former approach
is unsatisfactory as it is difficult to achieve the desired high
pressure levels with a chamber that can be easily
disassembled/reassembled. The latter approach is unsatisfactory as
most window materials cannot withstand the chamber fabrication
steps (e.g., brazing temperature).
[0059] FIGS. 7 and 8 illustrate a preferred port assembly 700 of
the invention which overcomes the previously cited problem of
member replacement after chamber completion. Although a cavitation
chamber that only uses port assemblies such as the one illustrated
in FIGS. 7 and 8 can be fabricated, the inventor has found that
preferably a cavitation chamber includes only one such port
assembly with the remaining port assemblies being of the type shown
in FIG. 6. Assuming that the dimensions of the various port
elements are selected according to the criteria provided herein,
such a system allows member 603 to be replaced after chamber
completion using the larger port of assembly 700.
[0060] As shown in the exploded view of FIG. 7, the primary
elements of this embodiment include a cone-shaped port 701, a
cone-shaped mounting ring 703 and a member 705. Member 705 can be a
window, gas feed-thru, liquid feed-thru, sensor (e.g.,
thermocouple), sensor coupler, mechanical feed-thru (e.g.,
manipulating arm), transducer coupler, plug, or any other suitably
shaped member.
[0061] The critical aspect of this embodiment is that the diameter
707 of member 705 must be smaller than the diameter 709 of port
701. As long as diameter 707 is smaller than diameter 709, member
705 can be replaced whenever desired without requiring the
disassembly of the chamber. If port assembly 700 is to be used in
conjunction with a port assembly 600 as previously described, the
diameter 605 of member 603 must be smaller than the diameter 709 of
port 701, thus allowing member 603 to be replaced through port 701
without disassembling the chamber.
[0062] As described in detail in co-pending application Ser. No.
10/925,070, filed Aug. 23, 2004, entitled Method of Fabricating a
Spherical Cavitation Chamber, the disclosure of which is
incorporated herein for any and all purposes, one method of
fabricating a high pressure cavitation chamber is to first
fabricate two spherical chamber halves and then join the two halves
to form the desired cavitation chamber. The two chamber halves can
be joined, for example, using a brazing operation in which the
brazing material is in the form of a thin ring with inside and
outside diameters of approximately the same size as those of the
cavitation chamber.
[0063] In accordance with a preferred embodiment of the present
invention, prior to joining the two chamber halves one or more
cone-shaped ports 701 are bored into one, or both, chamber halves
at the desired locations. It will be appreciated, however, that one
or more ports 701 can be bored into the chamber after the two
chamber halves are joined together. Before joining the chamber
halves, a number of cone-shaped mounting rings 703 corresponding to
the desired number of ports are placed between the two halves, and
then the two halves are joined together. As the mounting ring or
rings 703 must survive the joining process, e.g., brazing
operation, preferably ring 703 is fabricated from the same material
as the cavitation chamber (e.g., stainless steel). In an alternate
preferred embodiment ring 703 can be fabricated from a different
material, for example one with a higher melting point than the
cavitation chamber.
[0064] After cavitation chamber 101 has been completed, member 705
(e.g., a window) is placed through port 701. Mounting ring 703 is
then pulled into place within port 701 followed by member 705. If
at some point during the life of the cavitation chamber it becomes
necessary to replace member 705, the chamber pressure is released,
the cavitation liquid is drained and then the member mounting
procedure is simply reversed, the member is replaced and the
process is repeated (i.e., member 705 pushed into the chamber, ring
703 pushed into the chamber, member 705 removed, replacement member
705 located within the chamber, ring 703 pulled into place, and new
member 705 pulled into place).
[0065] In an alternate preferred embodiment, the cavitation chamber
includes at least one port assembly 700 and one or more port
assemblies 600. It will be appreciated that if additional port
assemblies 600 are required after chamber completion, the
additional port or ports 601 can be bored into the chamber after
the chamber has been constructed. In this embodiment prior to
assembling port assembly 700, each of the port assemblies 600 are
assembled. To assemble each port assembly 600, the corresponding
member 603 is inserted through port 701 and positioned within the
desired port 601. After all of the port assemblies 600 have been
completed, mounting ring 703 is pulled into place within port 701
followed by member 705. If it becomes necessary to replace a member
603, it can be replaced through port 701 after a standard port
disassembly procedure.
[0066] The inventor has found that a variety of tools can be used
to pull ring 703 and member 705 into place within port 701 and to
position member 603 within port 601. Accordingly the invention is
not limited to a specific assembly tool or tools. The following
assembly tools are only meant to be illustrative of a few of the
possible assembly methods and tools.
[0067] FIGS. 9-11 illustrate a tool 901 that can be used to pull
ring 703 into place. At the end of tool 901 are a plurality of
members 903; preferably three members 903 are used. Preferably
members 903 are fabricated from a spring steel or similar material,
the members designed to exert a force 905 away from the tool's
centerline 907. At the end of each member 903 is a grabbing surface
909. Surfaces 909 can be shaped so that when they are extended they
have a cone angle similar to that of member 705. Alternately
surfaces 909 can be coupled to members 903 by small flexible or
hinge-like joints allowing surfaces 909 to adapt to a variety of
different cone angles. Surfaces 909 can be comprised of a hard
material (e.g., stainless steel) or a semi-hard material (e.g.,
plastic) and may or may not include a softer, external surface (not
shown), for example comprised of an elastomeric material.
[0068] The distal end of members 903 are rigidly coupled together,
for example at a location 911. A tube 913 slides over members 903.
When tube 913 is positioned close to surfaces 909 and far from
distal end portion 915, surfaces 909 are compressed together, thus
allowing them to be pushed through ring 703. This step is
illustrated in FIG. 10 in which ring 703 is shown in phantom. After
ring 703 is properly positioned relative to surfaces 909, tube 913
is slid back close to distal end portion 915, causing members 903
to exert an outward force 905 on the internal surface of ring 703
(FIG. 11). Then tool 901 can be used to pull ring 703 in a
direction 1101, thus moving ring 703 into port 701 (wall 301 also
shown in phantom). Once the ring is in place, members 903 are again
compressed through movement of tube 913, thus allowing the removal
of tool 901.
[0069] As previously noted, there are countless ways to move member
705 into placed within ring 703 or to insert member 603 into port
601. Additionally it will be appreciated that the choice of the
method depends in part on the exact nature of member 705 or member
603. For example if the member is a gas feed-thru, it may already
include a tube that can be used to pull the member into
location.
[0070] One method of pulling member 705 into ring 703 or inserting
member 603 into port 601 is with a tool 1200 as illustrated in FIG.
12. The inventor has found that this tool is particularly useful
when the member in question is a window. Tool 1200 is comprised of
an end portion 1201 and a handle portion 1203. Within portion 1203
is a hole 1205. In the preferred embodiment, end portion 1201 is
disc shaped and handle portion 1203 is bar-shaped. Although end
portion 1201 and handle portion 1203 can be fabricated
individually, preferably they are fabricated from a single piece of
material. It will be appreciated that the dimensions of tool 1200
are determined in large part on the dimensions of the member in
question (i.e., member 603 or member 705) as well as the internal
diameter of chamber 101. For example, a larger member typically
requires a larger portion 1201 to insure sufficient holding
surface. Furthermore, the smaller the inside diameter of chamber
101, the smaller the overall dimensions of tool 1200 must be in
order to allow it to be manipulated within the chamber.
[0071] In the preferred method of using tool 1200, initially the
end surface 1207 of end portion 1201 is bonded to the outermost
surface of the member in question using an adhesive that can be
easily removed after the member is properly positioned within the
desired chamber port. Preferably tool 1200 is bonded to the member
prior to inserting the member into the chamber, thus minimizing the
risk of any adhesive contaminating or bonding to the inside surface
of the chamber.
[0072] Assuming that the member to be positioned is member 705,
preferably member 705 and attached tool 1200 are first inserted
into the chamber and then ring 703 is pulled into place. A small
rod with a hooked end is inserted into port 701 and the hooked end
is used to capture tool 1200 via hole 1205. The rod is then used to
pull member 705 into place. Once member 705 is locked into place,
for example with a retaining ring or plate as described below or
with an adhesive, tool 1200 is detached from member 705. The end
surface of member 705 is then cleaned to remove any remnants of the
adhesive.
[0073] Assuming that the member to be positioned is member 603,
preferably member 603 and attached tool 1200 are inserted into the
chamber through port 701. If member 603 is not partially coated
with an adhesive or sealant, typically a single rod can be used to
position member 603 within port 601. Often, however, it is
preferred to coat or partially coat the exterior cone-shaped
surface of member 603 with an adhesive (e.g., epoxy) so that it
remains within the port once positioned. Such adhesive is
especially important if other means of holding member 603 in place
(e.g., retaining ring or plate) are not practical, for example with
a non-machinable window, since member 603 must be held in place to
prevent it from falling within the chamber during degassing
procedures, vacuum operation of the chamber, etc. In these
circumstances two positioning rods are preferably used in order to
prevent any adhesive from accidentally being deposited on an
internal chamber surface. The hooked end of a first rod captures
member 603 via hole 1205 and passes the member into the chamber
through port 701. A second rod, also with a hooked end, is then
inserted through port 601. The second rod is then hooked into hole
1205 and the first rod is released from hole 1205 and removed from
the chamber. The second rod then pulls member 603 into place. After
member 603 is locked into place, tool 1200 is detached from member
603 and the end surface of member 603 is cleaned to remove any
remnants of adhesive. After all ports 600 have been assembled, port
assembly 700 can be assembled.
[0074] An alternate technique of moving a member into the desired
port is through the use of a tool 1301, shown in cross-section in
FIG. 13. At one end of tool 1301 is a cup-shaped, pliable member
1303. Handle 1305 of tool 1301 is hollow. By coupling handle 1305
to a suitable low vacuum source 1307, member 1303 can be used as a
suction cup. During use, cup-shaped member 1303 is placed against
the small diameter end of member 603 or 705, vacuum is applied, the
member (i.e., 603 or 705) is moved into place, and the vacuum is
discontinued allowing removal of tool 1301. Typically when tool
1301 is used with a member 603, tube 1305 is flexible, thus
allowing it to be inserted first through port 601 and then through
port 701. Member 603 is then attached to cup 1303, vacuum applied,
and member 603 drawn through port 701 into place within port
601.
[0075] In an alternate technique of moving a member into place, a
small loop 1401 is attached to the small diameter end of the
desired member with a removable adhesive (FIG. 14). After the
adhesive has cured, the member (either member 603 or member 705) is
positioned within the desired port following similar procedures to
those described above relative to tool 1200.
[0076] In the assembly shown in FIG. 8, the surfaces of mounting
ring 703 and member 705 that, upon assembly, become part of the
inner surface of the cavitation chamber are shown as flat. In a
preferred embodiment, however, these surfaces are curved to match
the spherical curvature of the internal surface of cavitation
chamber 101 as illustrated in FIG. 15. As shown, both surface 1501
of mounting ring 703 and surface 1503 of member 705 are shaped to
match the spherical curvature of surface 313 of chamber 101. It
will be understood, however, that if desired only one of these
surfaces may be curved while the other is flat (not shown).
[0077] Although the internal pressure of chamber 101 pushes both
ring 703 and member 705 outward, in one preferred embodiment of the
invention mounting ring 703 is coupled to chamber 101 with an
external retaining ring 1601 and a plurality of bolts 1603 (FIG.
16). External retaining ring 1601 can be fabricated with a slight
relief 1605, thus insuring that ring 703 is pulled tight within
port 701. Alternately and as shown in FIG. 17, mounting ring 703
can be fabricated such that it has a length slightly less than the
thickness of wall 301, thus insuring that a flat external retaining
ring 1701 is able to pull ring 703 tight within port 701.
Regardless of which external retaining ring design is used, the
surface that is in direct contact with the outer surface of chamber
101 can either be flat as shown in FIGS. 16 and 17, or curved as
shown in FIGS. 18 and 19.
[0078] For clarity, FIG. 20 is a frontal view of one of the
embodiments, specifically the assembly shown in FIG. 16. This view
shows the external surface of cavitation chamber 101, member 705,
the inside edge of mounting ring 703, external retaining ring 1601,
and bolts 1603. This figure, as with the other figures contained
herein, is only meant to illustrate the invention and should not be
considered to be a scale drawing.
[0079] In the embodiments illustrated in FIGS. 16-20, it was
assumed that it was desirable to leave the outermost surface of
member 705 uncovered, as would be required if member 705 was a
window. If member 705 is used for another purpose as previously
described (e.g., gas or liquid feed-thru, sensor, plug, etc.) then
the external retaining ring need not include an opening in the
middle. FIGS. 21 and 22 illustrate an example of such an
embodiment, this example utilizing the basic design features of the
retaining ring shown in FIGS. 16 and 20. It will be appreciated
that the retaining ring shown in any of FIGS. 17-19 could also be
used as the basis for a solid retaining plate.
[0080] As shown, retaining plate 2101 has a relief 2103, thus
allowing mounting ring 703 to be pulled tight within port 701 and
member 705 to be pulled tight within mounting ring 703. More
specifically, one or more bolts 2105 (four bolts 2105 are shown in
the illustrated embodiment) pull mounting ring 703 tight within
port 701 while one or more bolts 2107 (four bolts 2107 are shown in
the illustrated embodiment) pull member 705 tight within ring 703.
Although in the illustrated embodiment a feed-thru 2109 is shown,
as previously noted retaining plate 2101 could also be used to
mount a sensor, mechanical feed-thru, transducer coupler, plug, or
other member.
[0081] With respect to member 603, assuming that it is fabricated
from a material that can be machined as opposed to most window
material, a retaining plate similar to that shown in FIG. 21 can be
used to hold member 603 within port 601. As shown in FIG. 23,
retaining plate 2301 holds member 603 tightly within port 601. To
insure a tight fit, preferably either the uppermost surface 2303 of
member 603 is recessed relative to the outer surface 2305 of wall
301, the corresponding surface 2307 of plate 2301 is recessed
relative to surface 2303, or both as shown in FIG. 23. One or more
bolts 2309 pull member 603 tight within port 601. Although not
preferred, if desired one or more bolts 2311 can attach retaining
plate 2301 to chamber wall 301.
[0082] Although the embodiments shown above distribute the force on
the port member (i.e., 603 or 705), thus minimizing deformation
and/or breakage of the port member, in a preferred embodiment of
the invention a thin sheet or foil of metal is interposed between
the port member and either the mounting ring (for member 705) or
the port (for member 603). For example, FIG. 8 shows a foil 704,
for example of brass or other malleable metal, interposed between
member 705 and mounting ring 703. It will be appreciated that
although the inclusion of metal foil 704 is only indicated in FIG.
8, it can be used with any of the embodiments, not just the
embodiment shown in FIG. 8. Additionally it should be understood
that metal foil 704 is not required by the invention. It has been
found that metal foil 704 is primarily useful when the port member
(e.g., member 603 or member 705) is fabricated from a relatively
fragile material (e.g., glass or sapphire window). Additionally it
should be understood that a similar foil can be interposed between
mounting ring 703 and port 701.
[0083] In one preferred embodiment of the invention, a sealant
and/or adhesive is interposed between the adjacent surfaces of the
port assemblies. For example, a sealant and/or adhesive can be
interposed between mounting ring 703 and port 701, between member
705 and mounting ring 703, and/or between member 603 and port 601.
The use of an adhesive between the port member (i.e., member 603,
member 705) and the adjacent surface (i.e., port 601, ring 703) is
especially useful when the member is a window or similar material
that cannot be held in place with a bolt/retaining ring or
bolt/retaining plate assembly as previously described. The use of
an adhesive eliminates the need for a positive internal pressure to
keep the member in place, thus allowing a vacuum to be pulled
within the chamber which is useful during degassing and/or
operational procedures.
[0084] In one preferred embodiment of the invention, one or more
o-rings are interposed between the adjacent surfaces of the port
assemblies. For example, one or more o-rings can be interposed
between mounting ring 703 and port 701, between member 705 and
mounting ring 703, and/or between member 603 and port 601. FIG. 24
illustrates the use of multiple o-rings 2401 between the adjacent
surfaces of mounting ring 703 and port 701. FIG. 25 illustrates the
use of multiple o-rings 2501 between the adjacent surfaces of
mounting ring 703 and port 701. It will be appreciated that o-rings
can be used with any of the embodiments of the invention, for
example with member 603 and port 601.
[0085] FIG. 26 is a graph that illustrates the sonoluminescence
effect with a cavitation sphere and port assembly (with window
member) fabricated in accordance with the invention. The sphere was
fabricated from stainless steel and had an outer diameter of 9.5
inches and an inner diameter of 8 inches. Six acoustic drivers
(i.e., transducers) were mounted as illustrated in FIG. 1. For the
data shown in FIG. 26, the liquid within the chamber was acetone.
During operation, the temperature of the acetone was -27.5.degree.
C. The driving frequency was 23.52 kHz, the driving amplitude was
59 V RMS, and the driving power was 8.8 watts. Two acoustic cycles
are shown in FIG. 26. It will be appreciated that the data shown in
FIG. 26 is only provided for illustration, and that the invention
is not limited to this specific configuration.
[0086] As will be understood by those familiar with the art, the
present invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof.
Accordingly, the disclosures and descriptions herein are intended
to be illustrative, but not limiting, of the scope of the invention
which is set forth in the following claims.
* * * * *