U.S. patent application number 11/966458 was filed with the patent office on 2009-07-02 for ultrasonic treatment chamber for preparing emulsions.
This patent application is currently assigned to Kimberly-Clark Worldwide, Inc.. Invention is credited to John Glen Ahles, Thomas David Ehlert, Robert Allen Janssen, David William Koenig, Paul Warren Rasmussen, Steve Roffers, Scott W. Wenzel, Shiming Zhuang.
Application Number | 20090166177 11/966458 |
Document ID | / |
Family ID | 40796772 |
Filed Date | 2009-07-02 |
United States Patent
Application |
20090166177 |
Kind Code |
A1 |
Wenzel; Scott W. ; et
al. |
July 2, 2009 |
ULTRASONIC TREATMENT CHAMBER FOR PREPARING EMULSIONS
Abstract
An ultrasonic mixing system having a treatment chamber in which
at least two separate phases can be mixed to prepare an emulsion is
disclosed. Specifically, at least one phase is a dispersed phase
and one phase in a continuous phase. The treatment chamber has an
elongate housing through which the phases flow longitudinally from
a first inlet port and a second inlet port, respectively, to an
outlet port thereof. An elongate ultrasonic waveguide assembly
extends within the housing and is operable at a predetermined
ultrasonic frequency to ultrasonically energize the phases within
the housing. An elongate ultrasonic horn of the waveguide assembly
is disposed at least in part intermediate the inlet and outlet
ports, and has a plurality of discrete agitating members in contact
with and extending transversely outward from the horn intermediate
the inlet and outlet ports in longitudinally spaced relationship
with each other. The horn and agitating members are constructed and
arranged for dynamic motion of the agitating members relative to
the horn at the predetermined frequency and to operate in an
ultrasonic cavitation mode of the agitating members corresponding
to the predetermined frequency and the phases being mixed in the
chamber.
Inventors: |
Wenzel; Scott W.; (Neenah,
WI) ; Ahles; John Glen; (Neenah, WI) ; Ehlert;
Thomas David; (Neenah, WI) ; Janssen; Robert
Allen; (Alpharetta, GA) ; Koenig; David William;
(Menasha, WI) ; Rasmussen; Paul Warren; (Neenah,
WI) ; Roffers; Steve; (Neenah, WI) ; Zhuang;
Shiming; (Menasha, WI) |
Correspondence
Address: |
Christopher M. Goff (27839);ARMSTRONG TEASDALE LLP
ONE METROPOLITAN SQUARE, SUITE 2600
ST. LOUIS
MO
63102
US
|
Assignee: |
Kimberly-Clark Worldwide,
Inc.
Neenah
WI
|
Family ID: |
40796772 |
Appl. No.: |
11/966458 |
Filed: |
December 28, 2007 |
Current U.S.
Class: |
204/157.62 ;
137/826; 137/828; 366/127 |
Current CPC
Class: |
Y10T 137/2196 20150401;
B01F 3/0819 20130101; B01F 2215/0454 20130101; B01J 19/0066
20130101; B01F 11/0258 20130101; B01F 2215/045 20130101; Y10T
137/2185 20150401; B01J 19/24 20130101; B01J 19/006 20130101 |
Class at
Publication: |
204/157.62 ;
366/127; 137/826; 137/828 |
International
Class: |
B01J 19/10 20060101
B01J019/10; B01F 11/02 20060101 B01F011/02; F15C 1/22 20060101
F15C001/22 |
Claims
1. An ultrasonic mixing system for preparing an emulsion, the
mixing system comprising: a treatment chamber comprising: an
elongate housing having longitudinally opposite ends and an
interior space, the housing being generally closed at at least one
longitudinal end and having at least a first inlet port for
receiving a first phase for an emulsion, a second inlet port for
receiving a second phase for the emulsion into the interior space
of the housing, and at least one outlet port through which the
emulsion is exhausted from the housing following ultrasonic mixing
of the first and second phases to form the emulsion, the outlet
port being spaced longitudinally from the first and second inlet
ports such that the first and second phases flow longitudinally
within the interior space of the housing from the inlet ports to
the outlet port; and an elongate ultrasonic waveguide assembly
extending longitudinally within the interior space of the housing
and being operable at a predetermined ultrasonic frequency to
ultrasonically energize and mix the first and second phases flowing
within the housing, the waveguide assembly comprising an elongate
ultrasonic horn disposed at least in part intermediate the first
and second inlet ports and the outlet port of the housing and
having an outer surface located for contact with the first and
second phases flowing within the housing from the first and second
inlet ports to the outlet port, and a plurality of discrete
agitating members in contact with and extending transversely
outward from the outer surface of the horn intermediate the first
and second inlet ports and the outlet port in longitudinally spaced
relationship with each other, the agitating members and the horn
being constructed and arranged for dynamic motion of the agitating
members relative to the horn upon ultrasonic vibration of the horn
at the predetermined frequency and to operate in an ultrasonic
cavitation mode of the agitating members corresponding to the
predetermined frequency and the first and second phases being mixed
in the chamber.
2. The ultrasonic mixing system as set forth in claim 1 further
comprising a first delivery system operable to deliver the first
phase to the interior space of the housing of the treatment chamber
through the first inlet port and a second delivery system operable
to deliver the second phase to the interior space of the housing of
the treatment chamber through the second inlet port, wherein the
first phase and second phase are independently delivered at a rate
of from about 1 gram per minute to about 100,000 grams per
minute.
3. The ultrasonic mixing system as set forth in claim 1 wherein the
emulsion is selected from the group consisting of oil-in-water
emulsions, water-in-oil emulsions, water-in-oil-in-water emulsions,
oil-in-water-in-oil emulsions, water-in-silicone emulsions,
water-in-silicone-in-water emulsions, glycol-in-silicone emulsions,
and high internal phase emulsions.
4. The ultrasonic mixing system as set forth in claim 3 wherein the
first phase and second phase are independently selected from the
group consisting of an oil phase, a water phase, a silicone phase,
a glycol phase, and combinations thereof.
5. The ultrasonic mixing system as set forth in claim 4 wherein at
least one of the first phase and second phase further comprise a
surfactant.
6. The ultrasonic mixing system as set forth in claim 3 further
comprising a third inlet port for receiving a third phase for the
emulsion into the interior space of the housing, the third phase
being selected from the group consisting of an oil phase, a water
phase, a silicone phase, a glycol phase, and combinations
thereof.
7. The ultrasonic mixing system as set forth in claim 1 wherein the
predetermined frequency is in a range of from about 20 kHz to about
40 kHz.
8. The ultrasonic mixing system as set forth in claim 1 wherein the
horn has a terminal end within the interior space of the housing
and substantially spaced longitudinally from the inlet port to
define an intake zone therebetween within the interior space of the
housing.
9. An ultrasonic mixing system for preparing an oil-in-water
emulsion, the mixing system comprising: a treatment chamber
comprising: an elongate housing having longitudinally opposite ends
and an interior space, the housing being generally closed at at
least one longitudinal end and having at least a first inlet port
for receiving an oil phase into the interior space of the housing,
a second inlet port for receiving a water phase into the interior
space of the housing, and at least one outlet port through which an
oil-in-water emulsion is exhausted from the housing following
ultrasonic mixing of the oil phase and water phase to form the
oil-in-water emulsion, the outlet port being spaced longitudinally
from the inlet port such that the oil and water phases flow
longitudinally within the interior space of the housing from the
inlet port to the outlet port; an elongate ultrasonic waveguide
assembly extending longitudinally within the interior space of the
housing and being operable at a predetermined ultrasonic frequency
to ultrasonically energize and mix the oil and water phases flowing
within the housing, the waveguide assembly comprising an elongate
ultrasonic horn disposed at least in part intermediate the first
and second inlet ports and the outlet port of the housing and
having an outer surface located for contact with the oil water
phases flowing within the housing from the first and second inlet
ports to the outlet port, a plurality of discrete agitating members
in contact with and extending transversely outward from the outer
surface of the horn intermediate the first and second inlet ports
and the outlet port in longitudinally spaced relationship with each
other, the agitating members and the horn being constructed and
arranged for dynamic motion of the agitating members relative to
the horn upon ultrasonic vibration of the horn at the predetermined
frequency and to operate in an ultrasonic cavitation mode of the
agitating members corresponding to the predetermined frequency and
the oil water phases being mixed in the chamber, and a baffle
assembly disposed within the interior space of the housing and
extending at least in part transversely inward from the housing
toward the horn to direct longitudinally flowing oil and water
phases in the housing to flow transversely inward into contact with
the agitating members.
10. The ultrasonic mixing system as set forth in claim 9 further
comprising a first delivery system operable to deliver the oil
phase to the interior space of the housing of the treatment chamber
through the first inlet port and a second delivery system operable
to deliver the water phase to the interior space of the housing of
the treatment chamber through the second inlet port, wherein the
oil phase and the water phase are independently delivered to the
interior space of the housing at a rate of from about 1 gram per
minute to about 100,000 grams per minute.
11. The ultrasonic mixing system as set forth in claim 9 wherein
the oil phase further comprises a surfactant.
12. The ultrasonic mixing system as set forth in claim 9 wherein
the predetermined frequency is in a range of from about 20 kHz to
about 40 kHz.
13. The ultrasonic mixing system as set forth in claim 9 wherein
the horn has a terminal end within the interior space of the
housing and substantially spaced longitudinally from the inlet port
to define an intake zone therebetween within the interior space of
the housing.
14. A method for preparing an emulsion using the ultrasonic mixing
system of claim 1, the method comprising: delivering the first
phase via the first inlet port into the interior space of the
housing; delivering the second phase via the second inlet port into
the interior space of the housing; and ultrasonically mixing the
first and second phases via the elongate ultrasonic waveguide
assembly operating in the predetermined ultrasonic frequency.
15. The method as set forth in claim 14 wherein the first phase and
the second phase are independently delivered at a rate of from
about 1 gram per minute to about 100,000 grams per minute.
16. The method as set forth in claim 14 wherein the emulsion is
selected from the group consisting of oil-in-water emulsions,
water-in-oil emulsions, water-in-oil-in-water emulsions,
oil-in-water-in-oil emulsions, water-in-silicone emulsions,
water-in-silicone-in-water emulsions, glycol-in-silicone emulsions,
and high internal phase emulsions.
17. The method as set forth in claim 16 wherein the first phase and
second phase are independently selected from the group consisting
of an oil phase, a water phase, a silicone phase, a glycol phase,
and combinations thereof.
18. The method as set forth in claim 16 further comprising
delivering a third phase via a third inlet port into the interior
space of the housing, the third phase being selected from the group
consisting of an oil phase, a water phase, a silicone phase, a
glycol phase, and combinations thereof.
19. The method as set forth in claim 14 wherein at least one of the
first phase and the second phase are heated prior to being
delivered to the interior space of the housing.
20. The method as set forth in claim 14 wherein the first and
second phases are ultrasonically mixed using the predetermined
frequency being in a range of from about 20 kHz to about 40 kHz.
Description
FIELD OF DISCLOSURE
[0001] The present disclosure relates generally to systems for
ultrasonically mixing various phases to prepare an emulsion. More
particularly an ultrasonic mixing system is disclosed for
ultrasonically mixing at least a first phase and a second phase to
prepare an emulsion.
BACKGROUND OF DISCLOSURE
[0002] Many currently used products consist of one or more
emulsions. Specifically, there is a large array of cosmetic
emulsions utilized for application of skin health benefits to the
skin, hair, and body of a user. Additionally, many other emulsions
are used to provide benefits to inanimate objects such as, for
example, cleaning countertops, glass, and the like. Generally,
emulsions consist of a dispersed phase and a continuous phase and
are generally formed with the addition of a surfactant or a
combination of surfactants with varying hydrophilic/lipopilic
balances (HLB). Although emulsions are useful, current mixing
procedures have multiple problems, which can waste time, energy,
and money for manufacturers of these emulsions.
[0003] Specifically, emulsions are currently prepared in a
batch-type process, either by a cold mix or a hot mix procedure.
The cold mix procedure generally consists of multiple ingredients
or phases being added into a kettle in a sequential order with
agitation being applied via a blade, baffles, or a vortex. The hot
mix procedure is conducted similarly to the cold mix procedure with
the exception that the ingredients or phases are generally heated
above room temperature, for example to temperatures of from about
40 to about 100.degree. C., prior to mixing, and are then cooled
back to room temperature after the ingredients and phases have been
mixed. In both procedures, the various phases are added manually by
one of a number of methods including dumping, pouring, and/or
sifting.
[0004] These conventional methods of mixing phases into emulsions
have several problems. For example, as noted above, all phases are
manually added in a sequential order. Prior to adding the phases,
the ingredients for each phase need to be weighed, which can create
human error. Specifically, as the ingredients need to be weighed
one at a time, misweighing can occur with the additive amounts.
Furthermore, by manually adding the ingredients, there is a risk of
spilling or of incomplete transfers of the ingredients from one
container to the next.
[0005] One other major issue with conventional methods of mixing
phases to prepare emulsions is that batching processes (e.g., cold
and hot mix procedures described above) require heating times,
mixing times, and additive times that are entirely manual and left
up to the individual compounders to follow the instructions. These
practices can lead to inconsistencies from batch-to-batch and from
compounder to compounder. Furthermore, these procedures required
several hours to complete, which can get extremely expensive.
[0006] Based on the foregoing, there is a need in the art for a
mixing system that provides ultrasonic energy to enhance the mixing
of two or more phases into emulsions. Furthermore, it would be
advantageous if the system could be configured to enhance the
cavitation mechanism of the ultrasonics, thereby increasing the
probability that the phases will be effectively mixed to form the
emulsions.
SUMMARY OF DISCLOSURE
[0007] In one aspect, an ultrasonic mixing system for mixing at
least two phases to prepare an emulsion generally comprises a
treatment chamber comprising an elongate housing having
longitudinally opposite ends and an interior space. The housing is
generally closed at at least one of its longitudinal ends and has
at least a first inlet port for receiving at least a first phase
into the interior space of the housing, and a second inlet port for
receiving at least a second phase into the interior space of the
housing, and at least one outlet port through which an emulsion is
exhausted from the housing following ultrasonic mixing of the first
and second phases. The outlet port is spaced longitudinally from
the first and second inlet ports such that liquid (i.e., first
and/or second phases) flows longitudinally within the interior
space of the housing from the first and second inlet ports to the
outlet port. In one embodiment, the housing includes more than two
separate ports for receiving additional phases to be mixed to
prepare the emulsion. At least one elongate ultrasonic waveguide
assembly extends longitudinally within the interior space of the
housing and is operable at a predetermined ultrasonic frequency to
ultrasonically energize and mix the first and second phases (and
any additional phases) flowing within the housing.
[0008] The waveguide assembly generally comprises an elongate
ultrasonic horn disposed at least in part intermediate the first
and second inlet ports and the outlet port of the housing and has
an outer surface located for contact with the first and second
phases flowing within the housing from the first and second inlet
ports to the outlet port. A plurality of discrete agitating members
are in contact with and extend transversely outward from the outer
surface of the horn intermediate the first and second inlet ports
and the outlet port in longitudinally spaced relationship with each
other. The agitating members and the horn are constructed and
arranged for dynamic motion of the agitating members relative to
the horn upon ultrasonic vibration of the horn at the predetermined
frequency and to operate in an ultrasonic cavitation mode of the
agitating members corresponding to the predetermined frequency and
the first and second phases being mixed within the chamber.
[0009] As such the present disclosure is directed to an ultrasonic
mixing system for preparing an emulsion. The mixing system
comprises a treatment chamber comprising an elongate housing having
longitudinally opposite ends and an interior space, and an elongate
ultrasonic waveguide assembly extending longitudinally within the
interior space of the housing and being operable at a predetermined
ultrasonic frequency to ultrasonically energize and mix a first and
a second phase flowing within the housing to prepare the emulsion.
The housing is closed at at least one of its longitudinal ends and
has at least a first inlet port for receiving a first phase into
the interior space of the housing, and a second inlet port for
receiving a second phase into the interior space of the housing,
and at least one outlet port through which an emulsion is exhausted
from the housing following ultrasonic mixing of the first and
second phases. The outlet port is spaced longitudinally from the
first and second inlet ports such that the first and second phases
flow longitudinally within the interior space of the housing from
the first and second inlet ports to the outlet port.
[0010] The waveguide assembly comprises an elongate ultrasonic horn
disposed at least in part intermediate the first and second inlet
ports and the outlet port of the housing and having an outer
surface located for contact with the first and second phases
flowing within the housing from the first and second inlet ports to
the outlet port. Additionally, the waveguide assembly comprises a
plurality of discrete agitating members in contact with and
extending transversely outward from the outer surface of the horn
intermediate the first and second inlet ports and the outlet port
in longitudinally spaced relationship with each other. The
agitating members and the horn are constructed and arranged for
dynamic motion of the agitating members relative to the horn upon
ultrasonic vibration of the horn at the predetermined frequency and
to operate in an ultrasonic cavitation mode of the agitating
members corresponding to the predetermined frequency and the first
and second phases being mixed in the chamber.
[0011] The present invention is further directed to an ultrasonic
mixing system for preparing an oil-in-water emulsion. The mixing
system comprises a treatment chamber comprising an elongate housing
having longitudinally opposite ends and an interior space, and an
elongate ultrasonic waveguide assembly extending longitudinally
within the interior space of the housing and being operable at a
predetermined ultrasonic frequency to ultrasonically energize and
mix an oil phase and a water phase flowing within the housing. The
housing is generally closed at at least one of its longitudinal
ends and has at least a first inlet port for receiving the oil
phase into the interior space of the housing, and a second inlet
port for receiving the water phase into the interior space of the
housing, and at least one outlet port through which an oil-in-water
emulsion is exhausted from the housing following ultrasonic mixing
of the oil phase and water phase. The outlet port is spaced
longitudinally from the first and second inlet ports such that the
oil and water phases flow longitudinally within the interior space
of the housing from the first and second inlet ports to the outlet
port.
[0012] The waveguide assembly comprises an elongate ultrasonic horn
disposed at least in part intermediate the first and second inlet
ports and the outlet port of the housing and having an outer
surface located for contact with the oil and water phases flowing
within the housing from the first and second inlet ports to the
outlet port; a plurality of discrete agitating members in contact
with and extending transversely outward from the outer surface of
the horn intermediate the first and second inlet ports and the
outlet port in longitudinally spaced relationship with each other;
and a baffle assembly disposed within the interior space of the
housing and extending at least in part transversely inward from the
housing toward the horn to direct longitudinally flowing oil and
water phases in the housing to flow transversely inward into
contact with the agitating members. The agitating members and the
horn are constructed and arranged for dynamic motion of the
agitating members relative to the horn upon ultrasonic vibration of
the horn at the predetermined frequency and to operate in an
ultrasonic cavitation mode of the agitating members corresponding
to the predetermined frequency and the oil phase and water phase
being mixed in the chamber.
[0013] The present disclosure is further directed to a method for
preparing an emulsion using the ultrasonic mixing system described
above. The method comprises delivering the first phase via the
first inlet port into the interior space of the housing; delivering
the second phase via the second inlet port into the interior space
of the housing; and ultrasonically mixing the first and second
phases via the elongate ultrasonic waveguide assembly operating in
the predetermined ultrasonic frequency.
[0014] Other features of the present disclosure will be in part
apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a schematic of an ultrasonic mixing system
according to a first embodiment of the present disclosure for
preparing an emulsion.
[0016] FIG. 2 is a schematic of an ultrasonic mixing system
according to a second embodiment of the present disclosure for
preparing an emulsion.
[0017] Corresponding reference characters indicate corresponding
parts throughout the drawings.
DETAILED DESCRIPTION
[0018] With particular reference now to FIG. 1, in one embodiment,
an ultrasonic mixing system, generally indicated at 121, for mixing
phases to prepare an emulsion generally comprises a treatment
chamber, indicated at 151, that is operable to ultrasonically mix
various phases to form an emulsion, and further is capable of
creating a cavitation mode that allows for better mixing within the
housing of the chamber 151.
[0019] It is generally believed that as ultrasonic energy is
created by the waveguide assembly, increased cavitation of the
phases occurs, creating microbubbles. As these microbubbles then
collapse, the pressure within the chamber is increased forcibly
mixing the various phases to form an emulsion.
[0020] The terms "liquid" and "emulsion" are used interchangeably
to refer to a formulation comprised of two or more phases,
typically one phase being a dispersed phase and one phase being a
continuous phase. Furthermore, at least one of the phases is a
liquid such as a liquid-liquid emulsion, a liquid-gas emulsion, or
a liquid emulsion in which particulate matter is entrained, or
other viscous fluids.
[0021] The ultrasonic mixing system 121 is illustrated
schematically in FIG. 1 and further described herein with reference
to use of the treatment chamber 151 in the ultrasonic mixing system
to mix various phases to create an emulsion. The emulsion can be a
cosmetic emulsion for providing one of a variety of skin benefits
to a user's skin, hair, and/or body. For example, in one
embodiment, the cosmetic emulsion can be an oil-in-water emulsion
for cleansing the user's skin. It should be understood by one
skilled in the art, however, that while described herein with
respect to oil-in-water emulsions, the ultrasonic mixing system can
be used to mix various phases to prepare other types of emulsions
without departing from the scope of the present disclosure. For
example, other suitable emulsions can include water-in-oil
emulsions, water-in-oil-in-water emulsions, oil-in-water-in-oil
emulsions, water-in-silicone emulsions, water-in-silicone-in-water
emulsions, glycol-in-silicone emulsions, high internal phase
emulsions, and the like. Still other emulsions produced using the
ultrasonic treatment system of the present disclosure include hand
sanitizers, anti-aging lotions, wound care serums, teeth whitening
gels, animate and inanimate surface cleansers, wet wipe solutions,
suntan lotions, paints, inks, coatings, and polishes for both
industrial and consumer products.
[0022] In one particularly preferred embodiment, as illustrated in
FIG. 1, the treatment chamber 151 is generally elongate and has a
general inlet end 125 (a lower end in the orientation of the
illustrated embodiment) and a general outlet end 127 (an upper end
in the orientation of the illustrated embodiment). The treatment
chamber 151 is configured such that at least two phases enter the
treatment chamber 151 generally at the inlet end 125 thereof, flow
generally longitudinally within the chamber (e.g., upward in the
orientation of illustrated embodiment) and exit the chamber
generally at the outlet end 127 of the chamber.
[0023] The terms "upper" and "lower" are used herein in accordance
with the vertical orientation of the treatment chamber 151
illustrated in the various drawings and are not intended to
describe a necessary orientation of the chamber in use. That is,
while the chamber 151 is most suitably oriented vertically, with
the outlet end 127 of the chamber above the inlet end 125 as
illustrated in the drawing, it should be understood that the
chamber may be oriented with the inlet end above the outlet end and
the two phases are mixed as they travel downward through the
chamber, or it may be oriented other than in a vertical orientation
and remain within the scope of this disclosure. Furthermore, it
s
[0024] The terms "axial" and "longitudinal" refer directionally
herein to the vertical direction of the chamber 151 (e.g.,
end-to-end such as the vertical direction in the illustrated
embodiment of FIG. 1). The terms "transverse", "lateral" and
"radial" refer herein to a direction normal to the axial (e.g.,
longitudinal) direction. The terms "inner" and "outer" are also
used in reference to a direction transverse to the axial direction
of the treatment chamber 151, with the term "inner" referring to a
direction toward the interior of the chamber and the term "outer"
referring to a direction toward the exterior of the chamber.
[0025] The inlet end 125 of the treatment chamber 151 is typically
in fluid communication with at least one suitable delivery system
that is operable to direct one phase to, and more suitably through,
the chamber 151. More specifically, as illustrated in FIG. 1, two
delivery systems 128 and 129 are operable to direct a first phase
(not shown) and a second phase (not shown) through the chamber 151.
Typically, the delivery systems 128, 129 may independently comprise
one or more pumps 170 and 171, respectively, operable to pump the
respective phases from corresponding sources thereof to the inlet
end 125 of the chamber 151 via suitable conduits 132, 134.
[0026] It is understood that the delivery systems 128, 129 may be
configured to deliver more than one phase to the treatment chamber
151 without departing from the scope of this disclosure. It is also
contemplated that delivery systems other than that illustrated in
FIG. 1 and described herein may be used to deliver one or more
phases to the inlet end 125 of the treatment chamber 151 without
departing from the scope of this disclosure. It should be
understood that more than one phase can refer to two streams of the
same phase or different phases being delivered to the inlet end of
the treatment chamber without departing from the scope of the
present disclosure.
[0027] The treatment chamber 151 comprises a housing defining an
interior space 153 of the chamber 151 through which at least two
phases delivered to the chamber 151 flow from the inlet end 125 to
the outlet end 127 thereof. The chamber housing 151 suitably
comprises an elongate tube 155 generally defining, at least in
part, a sidewall 157 of the chamber 151. The tube 155 may have one
or more inlet ports (two inlet ports are generally indicated in
FIG. 1 at 156 and 158) formed therein through which at least two
separate phases to be mixed within the chamber 151 are delivered to
the interior space 153 thereof. It should be understood by one
skilled in the art that the inlet end of the housing may include
more than two inlet ports, more than three ports, and even more
than four ports. By way of example, although not shown, the housing
may comprise three inlet ports, wherein the first inlet port and
the second inlet port are suitably in parallel, spaced relationship
with each other, and the third inlet port is oriented on the
opposite sidewall of the housing from the first and second inlet
ports.
[0028] It should also be recognized by one skilled in the art that,
while preferably the inlet ports are disposed in close proximity to
one another in the inlet end, the inlet ports may be spaced farther
along the sidewall of the chamber from one another (see FIG. 2)
without departing from the scope of the present disclosure.
Specifically, as illustrated in FIG. 2, the first inlet port 228 is
disposed at the terminus of the inlet end, generally indicated at
211, and the second inlet port 229 is disposed longitudinally
between the inlet end 225 and the outlet end 227. This type of
configuration is beneficial when one or more of the phases to be
mixed are reactive or potentially unstable due to turbulence, heat,
or interaction with another phase or component. These reactive
components and/or phases can be added at an alternative point
(i.e., a second inlet port) located away from the first inlet port.
In an alternative embodiment, the reactive component and/or phase
can be added outside of the chamber such as via an in-line mixer to
the prepared emulsion once the emulsion exits the chamber.
[0029] Referring back to FIG. 1, the housing 151 comprises a
closure connected to and substantially closing the longitudinally
opposite end of the sidewall 157, and having at least one outlet
port 165 therein to generally define the outlet end 127 of the
treatment chamber. Alternatively, the housing comprises a closure
connected to and substantially closing the longitudinally end of
the side wall and having at least one inlet port 228 (see FIG. 2)
without departing from the scope of the present disclosure. The
sidewall (e.g., defined by the elongate tube) of the chamber has an
inner surface that together with the waveguide assembly (as
described below) and the closure define the interior space of the
chamber.
[0030] In the illustrated embodiment of FIG. 1, the tube 155 is
generally cylindrical so that the chamber sidewall 157 is generally
annular in cross-section. However, it is contemplated that the
cross-section of the chamber sidewall 157 may be other than
annular, such as polygonal or another suitable shape, and remains
within the scope of this disclosure. The chamber sidewall 157 of
the illustrated chamber 151 is suitably constructed of a
transparent material, although it is understood that any suitable
material may be used as long as the material is compatible with the
phases being mixed within the chamber, the pressure at which the
chamber is intended to operate, and other environmental conditions
within the chamber such as temperature.
[0031] A waveguide assembly, generally indicated at 203, extends
longitudinally at least in part within the interior space 153 of
the chamber 151 to ultrasonically energize the phases (and their
resulting-emulsions) flowing through the interior space 153 of the
chamber 151. In particular, the waveguide assembly 203 of the
illustrated embodiment extends longitudinally from the lower or
inlet end 125 of the chamber 151 up into the interior space 153
thereof to a terminal end 113 of the waveguide assembly disposed
intermediate the inlet port (e.g., inlet port 156 where it is
present) and outlet port (e.g., outlet port 165 where it is
present). Although illustrated in FIG. 1 as extending
longitudinally from the inlet end into the interior space 153 of
the chamber 151, it should be understood by one skilled in the art
that the waveguide assembly may extend longitudinally from the
outlet end downward into the interior space (see FIG. 2); that is
the waveguide assembly may be inverted within the chamber housing
without departing from the scope of the present disclosure.
Additionally, the waveguide assembly may extend laterally from a
housing sidewall of the chamber, running horizontally through the
interior space thereof without departing from the scope of the
present disclosure. Typically, the waveguide assembly 203 is
mounted, either directly or indirectly, to the chamber housing 151
as will be described later herein.
[0032] Still referring to FIG. 1, the waveguide assembly 203
suitably comprises an elongate horn assembly, generally indicated
at 133, disposed entirely with the interior space 153 of the
housing 151 intermediate the inlet ports 156, 158 and the outlet
port 165 for complete submersion within the liquid being treated
within the chamber 151, and more suitably, in the illustrated
embodiment, it is aligned coaxially with the chamber sidewall 157.
The horn assembly 133 has an outer surface 107 that together with
an inner surface 167 of the sidewall 157 defines a flow path within
the interior space 153 of the chamber 151 along which the two or
more phases (and the resulting-emulsion) flow past the horn within
the chamber (this portion of the flow path being broadly referred
to herein as the ultrasonic treatment zone). The horn assembly 133
has an upper end defining a terminal end of the horn assembly (and
therefore the terminal end 113 of the waveguide assembly) and a
longitudinally opposite lower end 111. Although not shown, it is
particularly preferable that the waveguide assembly 203 also
comprises a booster coaxially aligned with and connected at an
upper end thereof to the lower end 111 of the horn assembly 133. It
is understood, however, that the waveguide assembly 203 may
comprise only the horn assembly 133 and remain within the scope of
this disclosure. It is also contemplated that the booster may be
disposed entirely exterior of the chamber housing 151, with the
horn assembly 133 mounted on the chamber housing 151 without
departing from the scope of this disclosure.
[0033] The waveguide assembly 203, and more particularly the
booster is suitably mounted on the chamber housing 151, e.g., on
the tube 155 defining the chamber sidewall 157, at the upper end
thereof by a mounting member (not shown) that is configured to
vibrationally isolate the waveguide assembly (which vibrates
ultrasonically during operation thereof) from the treatment chamber
housing. That is, the mounting member inhibits the transfer of
longitudinal and transverse mechanical vibration of the waveguide
assembly 203 to the chamber housing 151 while maintaining the
desired transverse position of the waveguide assembly (and in
particular the horn assembly 133) within the interior space 153 of
the chamber housing and allowing both longitudinal and transverse
displacement of the horn assembly within the chamber housing. The
mounting member also at least in part (e.g., along with the
booster, lower end of the horn assembly) closes the inlet end 125
of the chamber 151. Examples of suitable mounting member
configurations are illustrated and described in U.S. Pat. No.
6,676,003, the entire disclosure of which is incorporated herein by
reference to the extent it is consistent herewith.
[0034] In one particularly suitable embodiment the mounting member
is of single piece construction. Even more suitably the mounting
member may be formed integrally with the booster (and more broadly
with the waveguide assembly 203). However, it is understood that
the mounting member may be constructed separately from the
waveguide assembly 203 and remain within the scope of this
disclosure. It is also understood that one or more components of
the mounting member may be separately constructed and suitably
connected or otherwise assembled together.
[0035] In one suitable embodiment, the mounting member is further
constructed to be generally rigid (e.g., resistant to static
displacement under load) so as to hold the waveguide assembly 203
in proper alignment within the interior space 153 of the chamber
151. For example, the rigid mounting member in one embodiment may
be constructed of a non-elastomeric material, more suitably metal,
and even more suitably the same metal from which the booster (and
more broadly the waveguide assembly 203) is constructed. The term
"rigid" is not, however, intended to mean that the mounting member
is incapable of dynamic flexing and/or bending in response to
ultrasonic vibration of the waveguide assembly 203. In other
embodiments, the rigid mounting member may be constructed of an
elastomeric material that is sufficiently resistant to static
displacement under load but is otherwise capable of dynamic flexing
and/or bending in response to ultrasonic vibration of the waveguide
assembly 203.
[0036] A suitable ultrasonic drive system 131 including at least an
exciter (not shown) and a power source (not shown) is disposed
exterior of the chamber 151 and operatively connected to the
booster (not shown) (and more broadly to the waveguide assembly
203) to energize the waveguide assembly to mechanically vibrate
ultrasonically. Examples of suitable ultrasonic drive systems 131
include a Model 20A3000 system available from Dukane Ultrasonics of
St. Charles, Ill., and a Model 2000CS system available from
Herrmann Ultrasonics of Schaumberg, Ill.
[0037] In one embodiment, the drive system 131 is capable of
operating the waveguide assembly 203 at a frequency in the range of
about 15 kHz to about 100 kHz, more suitably in the range of about
15 kHz to about 60 kHz, and even more suitably in the range of
about 20 kHz to about 40 kHz. Such ultrasonic drive systems 131 are
well known to those skilled in the art and need not be further
described herein.
[0038] In some embodiments, however not illustrated, the treatment
chamber can include more than one waveguide assembly having at
least two horn assemblies for ultrasonically treating and mixing
the phases together to prepare the emulsion. As noted above, the
treatment chamber comprises a housing defining an interior space of
the chamber through which the phases are delivered from an inlet
end. The housing comprises an elongate tube defining, at least in
part, a sidewall of the chamber. As with the embodiment including
only one waveguide assembly as described above, the tube may have
more than two inlet ports formed therein, through which at least
two phases to be mixed within the chamber are delivered to the
interior space thereof, and at least one outlet port through which
the emulsion exits the chamber.
[0039] In such an embodiment, two or more waveguide assemblies
extend longitudinally at least in part within the interior space of
the chamber to ultrasonically energize and mix the phases (and
resulting-emulsion) flowing through the interior space of the
chamber. Each waveguide assembly separately includes an elongate
horn assembly, each disposed entirely within the interior space of
the housing intermediate the inlet ports and the outlet port for
complete submersion within the phases being mixed within the
chamber. Each horn assembly can be independently constructed as
described more fully herein (including the horns, along with the
plurality of agitating members and baffle assemblies).
[0040] Referring back to FIG. 1, the horn assembly 133 comprises an
elongate, generally cylindrical horn 105 having an outer surface
107, and two or more (i.e., a plurality of) agitating members 137
connected to the horn and extending at least in part transversely
outward from the outer surface of the horn in longitudinally spaced
relationship with each other. The horn 105 is suitably sized to
have a length equal to about one-half of the resonating wavelength
(otherwise commonly referred to as one-half wavelength) of the
horn. In one particular embodiment, the horn 105 is suitably
configured to resonate in the ultrasonic frequency ranges recited
previously, and most suitably at 20 kHz. For example, the horn 105
may be suitably constructed of a titanium alloy (e.g.,
Ti.sub.6Al.sub.4V) and sized to resonate at 20 kHz. The one-half
wavelength horn 105 operating at such frequencies thus has a length
(corresponding to a one-half wavelength) in the range of about 4
inches to about 6 inches, more suitably in the range of about 4.5
inches to about 5.5 inches, even more suitably in the range of
about 5.0 inches to about 5.5 inches, and most suitably a length of
about 5.25 inches (133.4 mm). It is understood, however, that the
treatment chamber 151 may include a horn 105 sized to have any
increment of one-half wavelength without departing from the scope
of this disclosure.
[0041] In one embodiment (not shown), the agitating members 137
comprise a series of five washer-shaped rings that extend
continuously about the circumference of the horn in longitudinally
spaced relationship with each other and transversely outward from
the outer surface of the horn. In this manner the vibrational
displacement of each of the agitating members relative to the horn
is relatively uniform about the circumference of the horn. It is
understood, however, that the agitating members need not each be
continuous about the circumference of the horn. For example, the
agitating members may instead be in the form of spokes, blades,
fins or other discrete structural members that extend transversely
outward from the outer surface of the horn. For example, as
illustrated in FIG. 1, one of the five agitating members is in a
T-shape 701. Specifically, the T-shaped agitating member 701
surrounds the nodal region. It has been found that members in the
T-shape, generate a strong radial (e.g., horizontal) acoustic wave
that further increases the cavitation effect as described more
fully herein.
[0042] By way of a dimensional example, the horn assembly 133 of
the illustrated embodiment of FIG. 1 has a length of about 5.25
inches (133.4 mm), one of the rings 137 is suitably disposed
adjacent the terminal end 113 of the horn 105 (and hence of the
waveguide assembly 203), and more suitably is longitudinally spaced
approximately 0.063 inches (1.6 mm) from the terminal end of the
horn 105. In other embodiments the uppermost ring may be disposed
at the terminal end of the horn 105 and remain within the scope of
this disclosure. The rings 137 are each about 0.125 inches (3.2 mm)
in thickness and are longitudinally spaced from each other (between
facing surfaces of the rings) a distance of about 0.875 inches
(22.2 mm).
[0043] It is understood that the number of agitating members 137
(e.g., the rings in the illustrated embodiment) may be less than or
more than five without departing from the scope of this disclosure.
It is also understood that the longitudinal spacing between the
agitating members 137 may be other than as illustrated in FIG. 1
and described above (e.g., either closer or spaced further apart).
Furthermore, while the rings 137 illustrated in FIG. 1 are equally
longitudinally spaced from each other, it is alternatively
contemplated that where more than two agitating members are present
the spacing between longitudinally consecutive agitating members
need not be uniform to remain within the scope of this
disclosure.
[0044] In particular, the locations of the agitating members 137
are at least in part a function of the intended vibratory
displacement of the agitating members upon vibration of the horn
assembly 133. For example, in the illustrated embodiment of FIG. 1,
the horn assembly 133 has a nodal region located generally
longitudinally centrally of the horn 105 (e.g., at the third ring).
As used herein and more particularly shown in FIG. 1, the "nodal
region" of the horn 105 refers to a longitudinal region or segment
of the horn member along which little (or no) longitudinal
displacement occurs during ultrasonic vibration of the horn and
transverse (e.g., radial in the illustrated embodiment)
displacement of the horn is generally maximized. Transverse
displacement of the horn assembly 133 suitably comprises transverse
expansion of the horn but may also include transverse movement
(e.g., bending) of the horn.
[0045] In the illustrated embodiment of FIG. 1, the configuration
of the one-half wavelength horn 105 is such that the nodal region
is particularly defined by a nodal plane (i.e., a plane transverse
to the horn member at which no longitudinal displacement occurs
while transverse displacement is generally maximized) is present.
This plane is also sometimes referred to as a "nodal point".
Accordingly, agitating members 137 (e.g., in the illustrated
embodiment, the rings) that are disposed longitudinally further
from the nodal region of the horn 105 will experience primarily
longitudinal displacement while agitating members that are
longitudinally nearer to the nodal region will experience an
increased amount of transverse displacement and a decreased amount
of longitudinal displacement relative to the longitudinally distal
agitating members.
[0046] It is understood that the horn 105 may be configured so that
the nodal region is other than centrally located longitudinally on
the horn member without departing from the scope of this
disclosure. It is also understood that one or more of the agitating
members 137 may be longitudinally located on the horn so as to
experience both longitudinal and transverse displacement relative
to the horn upon ultrasonic vibration of the horn 105.
[0047] Still referring to FIG. 1, the agitating members 137 are
sufficiently constructed (e.g., in material and/or dimension such
as thickness and transverse length, which is the distance that the
agitating member extends transversely outward from the outer
surface 107 of the horn 105) to facilitate dynamic motion, and in
particular dynamic flexing/bending of the agitating members in
response to the ultrasonic vibration of the horn. In one
particularly suitable embodiment, for a given ultrasonic frequency
at which the waveguide assembly 203 is to be operated in the
treatment chamber (otherwise referred to herein as the
predetermined frequency of the waveguide assembly) and a particular
liquid to be treated within the chamber 151, the agitating members
137 and horn 105 are suitably constructed and arranged to operate
the agitating members in what is referred to herein as an
ultrasonic cavitation mode at the predetermined frequency.
[0048] As used herein, the ultrasonic cavitation mode of the
agitating members refers to the vibrational displacement of the
agitating members sufficient to result in cavitation (i.e., the
formation, growth, and implosive collapse of bubbles in a liquid)
of the emulsion being prepared at the predetermined ultrasonic
frequency. For example, where at least one of the phases for the
emulsion flowing within the chamber comprises an aqueous phase, and
the ultrasonic frequency at which the waveguide assembly 203 is to
be operated (i.e., the predetermined frequency) is about 20 kHZ,
one or more of the agitating members 137 are suitably constructed
to provide a vibrational displacement of at least 1.75 mils (i.e.,
0.00175 inches, or 0.044 mm) to establish a cavitation mode of the
agitating members. Similarly, when at least one of the phases for
the emulsion is a hydrophobic phase (e.g., oil), and the ultrasonic
frequency is about 20 kHz, one ore more of the agitating members
137 are suitable constructed to provide a vibrational displacement
of at least 1.75 mils. To establish a cavitation mode of the
agitating members.
[0049] It is understood that the waveguide assembly 203 may be
configured differently (e.g., in material, size, etc.) to achieve a
desired cavitation mode associated with the particular emulsion to
be prepare. For example, as the viscosity of the phases being mixed
to prepare the emulsion changes, the cavitation mode of the
agitating members may need to be changed.
[0050] In particularly suitable embodiments, the cavitation mode of
the agitating members corresponds to a resonant mode of the
agitating members whereby vibrational displacement of the agitating
members is amplified relative to the displacement of the horn.
However, it is understood that cavitation may occur without the
agitating members operating in their resonant mode, or even at a
vibrational displacement that is greater than the displacement of
the horn, without departing from the scope of this disclosure.
[0051] In one suitable embodiment, a ratio of the transverse length
of at least one and, more suitably, all of the agitating members to
the thickness of the agitating member is in the range of about 2:1
to about 6:1. As another example, the rings each extend
transversely outward from the outer surface 107 of the horn 105 a
length of about 0.5 inches (12.7 mm) and the thickness of each ring
is about 0.125 inches (3.2 mm), so that the ratio of transverse
length to thickness of each ring is about 4:1. It is understood,
however that the thickness and/or the transverse length of the
agitating members may be other than that of the rings as described
above without departing from the scope of this disclosure. Also,
while the agitating members 137 (rings) may suitably each have the
same transverse length and thickness, it is understood that the
agitating members may have different thicknesses and/or transverse
lengths.
[0052] In the above described embodiment, the transverse length of
the agitating member also at least in part defines the size (and at
least in part the direction) of the flow path along which the
phases or other flowable components in the interior space of the
chamber flows past the horn. For example, the horn may have a
radius of about 0.875 inches (22.2 mm) and the transverse length of
each ring is, as discussed above, about 0.5 inches (12.7 mm). The
radius of the inner surface of the housing sidewall is
approximately 1.75 inches (44.5 mm) so that the transverse spacing
between each ring and the inner surface of the housing sidewall is
about 0.375 inches (9.5 mm). It is contemplated that the spacing
between the horn outer surface and the inner surface of the chamber
sidewall and/or between the agitating members and the inner surface
of the chamber sidewall may be greater or less than described above
without departing from the scope of this disclosure.
[0053] In general, the horn 105 may be constructed of a metal
having suitable acoustical and mechanical properties. Examples of
suitable metals for construction of the horn 105 include, without
limitation, aluminum, monel, titanium, stainless steel, and some
alloy steels. It is also contemplated that all or part of the horn
105 may be coated with another metal such as silver, platinum,
gold, palladium, lead dioxide, and copper to mention a few. In one
particularly suitable embodiment, the agitating members 137 are
constructed of the same material as the horn 105, and are more
suitably formed integrally with the horn. In other embodiments, one
or more of the agitating members 137 may instead be formed separate
from the horn 105 and connected thereto.
[0054] While the agitating members 137 (e.g., the rings)
illustrated in FIG. 1 are relatively flat, i.e., relatively
rectangular in cross-section, it is understood that the rings may
have a cross-section that is other than rectangular without
departing from the scope of this disclosure. The term
"cross-section" is used in this instance to refer to a
cross-section taken along one transverse direction (e.g., radially
in the illustrated embodiment) relative to the horn outer surface
107). Additionally, as seen of the first two and last two agitating
members 137 (e.g., the rings) illustrated in FIG. 1 are constructed
only to have a transverse component, it is contemplated that one or
more of the agitating members may have at least one longitudinal
(e.g., axial) component to take advantage of transverse vibrational
displacement of the horn (e.g., at the third agitating member as
illustrated in FIG. 1) during ultrasonic vibration of the waveguide
assembly 203.
[0055] As best illustrated in FIG. 1, the terminal end 113 of the
waveguide assembly (e.g., of the horn 105 in the illustrated
embodiment) is suitably spaced longitudinally from the outlet port
165 at the outlet end 127 in FIG. 1 to define what is referred to
herein as a buffer zone (i.e., the portion of the interior space
153 of the chamber housing 151 longitudinally beyond the terminal
end 113 of the waveguide assembly 203) to allow more uniform mixing
of components as the phases (and resulting-emulsion) flow
downstream of the terminal end 112 to the outlet end 127 of the
chamber 151. For example, in one suitable embodiment, the buffer
zone has a void volume (i.e., the volume of that portion of the
open space 153 within the chamber housing 151 within the buffer
zone) in which the ratio of this buffer zone void volume to the
void volume of the remainder of the chamber housing interior space
upstream of the terminal end of the waveguide assembly is suitably
in the range of from about 0.01:1 to about 5.0:1, and more suitably
about 1:1.
[0056] Providing the illustrated buffer zone is particularly
suitable where the chamber 151 is used for mixing phases together
to form an emulsion as the longitudinal spacing between the
terminal end 113 of the waveguide assembly 203 and the outlet port
165 of the chamber 151 provides sufficient space for the agitated
flow of the mixed emulsion to generally settle prior to the
emulsion exiting the chamber via the outlet port 127. This is
particularly useful where, as in the illustrated embodiment, one of
the agitating members 137 is disposed at or adjacent the terminal
end of the horn 113. While such an arrangement leads to beneficial
back-mixing of the emulsion as it flows past the terminal end of
the horn 113, it is desirable that this agitated flow settle out at
least in part before exiting the chamber. It is understood, though,
that the terminal end 113 of the horn 105 may be nearer to the
outlet end 127 than is illustrated in FIG. 1, and may be
substantially adjacent to the outlet port 165 so as to generally
omit the buffer zone, without departing from the scope of this
disclosure.
[0057] Additionally, a baffle assembly, generally indicated at 245
is disposed within the interior space 153 of the chamber housing
151, and in particular generally transversely adjacent the inner
surface 167 of the sidewall 157 and in generally transversely
opposed relationship with the horn 105. In one suitable embodiment,
the baffle assembly 245 comprises one or more baffle members 247
disposed adjacent the inner surface 167 of the housing sidewall 157
and extending at least in part transversely inward from the inner
surface of the sidewall 167 toward the horn 105. More suitably, the
one or more baffle members 247 extend transversely inward from the
housing sidewall inner surface 167 to a position longitudinally
intersticed with the agitating members 137 that extend outward from
the outer surface 107 of the horn 105. The term "longitudinally
intersticed" is used herein to mean that a longitudinal line drawn
parallel to the longitudinal axis of the horn 105 passes through
both the agitating members 137 and the baffle members 247. As one
example, in the illustrated embodiment, the baffle assembly 245
comprises four, generally annular baffle members 247 (i.e.,
extending continuously about the horn 105) longitudinally
intersticed with the five agitating members 237.
[0058] As a more particular example, the four annular baffle
members 247 illustrated in FIG. 1 are of the same thickness as the
agitating members 137 in our previous dimensional example (i.e.,
0.125 inches (3.2 mm)) and are spaced longitudinally from each
other (e.g., between opposed faces of consecutive baffle members)
equal to the longitudinal spacing between the rings (i.e., 0.875
inches (22.2 mm)). Each of the annular baffle members 247 has a
transverse length (e.g., inward of the inner surface 167 of the
housing sidewall 157) of about 0.5 inches (12.7 mm) so that the
innermost edges of the baffle members extend transversely inward
beyond the outermost edges of the agitating members 137 (e.g., the
rings). It is understood, however, that the baffle members 247 need
not extend transversely inward beyond the outermost edges of the
agitating members 137 of the horn 105 to remain within the scope of
this disclosure.
[0059] It will be appreciated that the baffle members 247 thus
extend into the flow path of the phases (and resulting-emulsion)
that flow within the interior space 153 of the chamber 151 past the
horn 105 (e.g., within the ultrasonic treatment zone). As such, the
baffle members 247 inhibit the phases from flowing along the inner
surface 167 of the chamber sidewall 157 past the horn 105, and more
suitably the baffle members facilitate the flow of the phases
transversely inward toward the horn for flowing over the agitating
members of the horn to thereby facilitate ultrasonic energization
(i.e., agitation) of the phases to initiate mixing of the phases to
form an emulsion.
[0060] In one embodiment, to inhibit gas bubbles against stagnating
or otherwise building up along the inner surface 167 of the
sidewall 157 and across the face on the underside of each baffle
member 247, e.g., as a result of agitation of the phases within the
chamber, a series of notches (broadly openings) may be formed in
the outer edge of each of the baffle members (not shown) to
facilitate the flow of gas (e.g., gas bubbles) between the outer
edges of the baffle members and the inner surface of the chamber
sidewall. For example, in one particularly preferred embodiment,
four such notches are formed in the outer edge of each of the
baffle members in equally spaced relationship with each other. It
is understood that openings may be formed in the baffle members
other than at the outer edges where the baffle members abut the
housing, and remain within the scope of this disclosure. It is also
understood, that these notches may number more or less than four,
as discussed above, and may even be completely omitted.
[0061] It is further contemplated that the baffle members 247 need
not be annular or otherwise extend continuously about the horn 105.
For example, the baffle members 247 may extend discontinuously
about the horn 105, such as in the form of spokes, bumps, segments
or other discrete structural formations that extend transversely
inward from adjacent the inner surface 167 of the housing sidewall
157. The term "continuously" in reference to the baffle members 247
extending continuously about the horn does not exclude a baffle
member as being two or more arcuate segments arranged in end-to-end
abutting relationship, i.e., as long as no significant gap is
formed between such segments. Suitable baffle member configurations
are disclosed in U.S. application Ser. No. 11/530,311 (filed Sep.
8, 2006), which is hereby incorporated by reference to the extent
it is consistent herewith.
[0062] Also, while the baffle members 247 illustrated in FIG. 1 are
each generally flat, e.g., having a generally thin rectangular
cross-section, it is contemplated that one or more of the baffle
members may each be other than generally flat or rectangular in
cross-section to further facilitate the flow of bubbles along the
interior space 153 of the chamber 151. The term "cross-section" is
used in this instance to refer to a cross-section taken along one
transverse direction (e.g., radially in the illustrated embodiment,
relative to the horn outer surface 107).
[0063] As described above, in some embodiments, the waveguide
assembly may be inverted within the chamber. Specifically, as shown
in FIG. 2, the waveguide assembly 303 is mounted to the chamber
housing 251 at the outlet end 227 and extends longitudinally
downward within the interior space 253 of the chamber housing 251.
The first and second phases (not shown) enter the chamber 251
through inlet ports 228 and 229 and travel longitudinally upward
towards the terminal end of the horn 213 (and, as illustrated, the
terminal end of the waveguide assembly) where the phases are
ultrasonically energized and mixed to form an emulsion. Once mixed,
the emulsion travels to the outlet end 227 of the chamber 251 and
exits the chamber 251 through the outlet port 265.
[0064] In one embodiment, although not illustrated, the ultrasonic
mixing system may further comprise a filter assembly disposed at
the outlet end of the treatment chamber. Many emulsions, when
initially prepared, can contain one or more components within the
various phases that attract one another and can clump together in
large balls. Furthermore, many times, particles within the prepared
emulsions can settle out over time and attract one another to form
large balls; referred to as reagglomeration. As such, the filter
assembly can filter out the large balls of particles that form
within the emulsions prior to the emulsion being delivered to an
end-product for consumer use. Specifically, the filter assembly is
constructed to filter out particles sized greater than about 0.2
microns.
[0065] Specifically, in one particularly preferred embodiment, the
filter assembly covers the inner surface of the outlet port. The
filter assembly includes a filter having a pore size of from about
0.5 micron to about 20 microns. More suitably, the filter assembly
includes a filter having a pore size of from about 1 micron to
about 5 microns, and even more suitably, about 2 microns. The
number and pour size of filters for use in the filter assembly will
typically depend on the formulation (and its components) to be
mixed within the treatment chamber.
[0066] A degasser may also be included in the ultrasonic mixing
system. For example, once the prepared emulsion exits the treatment
chamber, the emulsion flows into a degasser in which excess gas
bubbles are removed from the emulsion prior to the emulsion being
used into a consumer end-products, such as a cosmetic
formulation.
[0067] One particularly preferred degasser is a continuous flow
gas-liquid cyclone separator, such as commercially available from
NATCO (Houston, Tex.). It should be understood by a skilled
artisan, however, that any other system that separates gas from an
emulsion by centrifugal action can suitably be used without
departing from the present disclosure.
[0068] In operation according to one embodiment of the ultrasonic
mixing system of the present disclosure, the mixing system (more
specifically, the treatment chamber) is used to mix two or more
phases together to form an emulsion. Specifically, at least a first
phase is delivered (e.g., by the pumps described above) via
conduits to a first inlet port formed in the treatment chamber
housing and a second phase is delivered (e.g., by the pumps
described above) via separate conduits to a second inlet port
formed in the treatment chamber housing. The phases can be any
suitable phases for forming emulsions known in the art. Suitable
phases can include, for example, an oil phase, a water phase, a
silicone phase, a glycol phase, and combinations thereof. When
mixed in various combinations, the phases form emulsions such as
oil-in-water emulsions, water-in-oil emulsions,
water-in-oil-in-water emulsions, oil-in-water-in-oil emulsions,
water-in-silicone emulsions, water-in-silicone-in-water emulsions,
glycol-in-silicone emulsion, high internal phase emulsions,
hydrogels, and the like. High internal phase emulsions are well
known in the art and typically refer to emulsions having from about
70% (by total weight emulsion) to about 80% (by total weight
emulsion) of an oil phase. Furthermore, as known by one skilled in
the art, "hydrogel" typically refers to a hydrophilic base that is
thickened with rheology modifiers and or thickeners to form a gel.
For example a hydrogel can be formed with a base consisting of
water that is thickened with a carbomer that has been neutralized
with a base.
[0069] Without being limited, the present disclosure will describe
a method of preparing an oil-in-water emulsion using the ultrasonic
mixing system as described herein. It should be recognized that
while described in terms of preparing an oil-in-water emulsion, any
of the above-listed emulsions may be prepared using the general
process described without departing from the scope of the present
disclosure. Generally, the method for preparing the oil-in-water
emulsion includes: delivering a first phase (i.e., an oil phase)
via a first inlet port into the interior space of the treatment
chamber housing and a second phase (i.e., a water phase) via a
second inlet port into the interior space of the treatment chamber
housing. Typically, as described more fully above, the first and
second inlet ports are disposed in parallel along the sidewall of
the treatment chamber housing. In an alternative embodiment, the
first and second inlet ports are disposed on opposite sidewalls of
the treatment chamber housing. While described herein as having two
inlet ports, it should be understood by one skilled in the art that
more than two inlet ports can be used to deliver the various phases
to be mixed without departing from the scope of the present
disclosure.
[0070] Particularly preferred oil-in-water emulsions can be
prepared with an oil phase including from about 0.1% (by total
weight of oil phase) to about 99% (by total weight of oil phase)
oil. More suitably, the oil phase includes from about 1% (by total
weight of oil phase) to about 80% (by total weight of oil phase)
oil and, even more suitably, from about 5% (by total weight of oil
phase) to about 50% (by total weight of oil phase) oil. The oils
can be natural oil, synthetic oils, and combinations thereof.
[0071] The term "natural oil" is intended to include oils,
essential oils, and combinations thereof. Suitable oils include
Apricot Kernel Oil, Avocado Oil, Babassu Oil, Borage Seed Oil,
Camellia Oil, Canola Oil, Carrot Oil, Cashew Nut Oil, Castor Oil,
Cherry Pit Oil, Chia Oil, Coconut Oil, Cod Liver Oil, Corn Germ
Oil, Corn Oil, Cottonseed Oil, Egg Oil, Epoxidized Soybean Oil,
Evening Primrose Oil, Grape Seed Oil, Hazelnut Oil, Hybrid
Safflower Oil, Hybrid Sunflower Seed Oil, Hydrogenated Castor Oil,
Hydrogenated Castor Oil Laurate, Hydrogenated Coconut Oil,
Hydrogenated Cottonseed Oil, Hydrogenated Fish Oil, Hydrogenated
Menhaden Oil, Hydrogenated Mink Oil, Hydrogenated Orange Roughy
Oil, Hydrogenated Palm Kernel Oil, Hydrogenated Palm Oil,
Hydrogenated Peanut Oil, Hydrogenated Shark Liver Oil, Hydrogenated
Soybean Oil, Hydrogenated Vegetable Oil, Lanolin and Lanolin
Derivatives, Lesquerella Oil, Linseed Oil, Macadamia Nut Oil,
Maleated Soybean Oil, Meadowfoam Seed Oil, Menhaden Oil, Mink Oil,
Moringa Oil, Mortierella Oil, Neatsfoot Oil, Olive Husk Oil, Olive
Oil, Orange Roughy Oil, Palm Kernel Oil, Palm Oil, Peach Kernel
Oil, Peanut Oil, Pengawar Djambi Oil, Pistachio Nut Oil, Rapeseed
Oil, Rice Bran Oil, Safflower Oil, Sesame Oil, Shark Liver Oil,
Soybean Oil, Sunflower Seed Oil, Sweet Almond Oil, Tall Oil,
Vegetable Oil, Walnut Oil, Wheat Bran Lipids, Wheat Germ Oil,
Zadoary Oil, oil extracts of various other botanicals, and other
vegetable or partially hydrogenated vegetable oils, and the like,
as well as mixtures thereof.
[0072] Suitable essential oils include Anise Oil, Balm Mint Oil,
Basil Oil, Bee Balm Oil, Bergamot Oil, Birch Oil, Bitter Almond
Oil, Bitter Orange Oil, Calendula Oil, California Nutmeg Oil,
Caraway Oil, Cardamom Oil, Chamomile Oil, Cinnamon Oil, Clary Oil,
Cloveleaf Oil, Clove Oil, Coriander Oil, Cypress Oil, Eucalyptus
Oil, Fennel Oil, Gardenia Oil, Geranium Oil, Ginger Oil, Grapefruit
Oil, Hops Oil, Hyptis Oil, Indigo Bush Oil, Jasmine Oil, Juniper
Oil, Kiwi Oil, Laurel Oil, Lavender Oil, Lemongrass Oil, Lemon Oil,
Linden Oil, Lovage Oil, Mandarin Orange Oil, Matricaria Oil, Musk
Rose Oil, Nutmeg Oil, Olibanum, Orange Flower Oil, Orange Oil,
Patchouli Oil, Pennyroyal Oil, Peppermint Oil, Pine Oil, Pine Tar
Oil, Rose Hips Oil, Rosemary Oil, Rose Oil, Rue Oil, Sage Oil,
Sambucus Oil, Sandalwood Oil, Sassafras Oil, Silver Fir Oil,
Spearmint Oil, Sweet Marjoram Oil, Sweet Violet Oil, Tar Oil, Tea
Tree Oil, Thyme Oil, Wild Mint Oil, Yarrow Oil, Ylang Ylang Oil,
and the like, as well as mixtures thereof.
[0073] Some preferred natural oils include, but are not limited to
Avocado Oil, Apricot Oil, Babassu Oil, Borage Oil, Camellia oil,
Canola oil, Castor Oil, Coconut oil, Corn Oil, Cottonseed Oil,
Evening Primrose Oil, Hydrogenated Cottonseed Oil, Hydrogenated
Palm Kernel Oil, Maleated Soybean Oil, Meadowfoam Oil, Palm Kernel
Oil, Phospholipids, Rapeseed Oil, Rose Hip Oil, Sunflower Oil,
Soybean Oil, and the like, as well as mixtures thereof.
[0074] The term "synthetic oil" is intended to include synthetic
oils, esters, silicones, other emollients, and combinations
thereof. Examples of suitable synthetic oils include petrolatum and
petrolatum based oils, mineral oils, mineral jelly, isoparaffins,
polydimethylsiloxanes such as methicone, cyclomethicone,
dimethicone, dimethiconol, trimethicone, alkyl dimethicones, alkyl
methicones, alkyldimethicone copolyols, organo-siloxanes (i.e.,
where the organic functionality can be selected from alkyl, phenyl,
amine, polyethylene glycol, amine-glycol, alkylaryl, carboxal, and
the like), silicones such as silicone elastomer, phenyl silicones,
alkyl trimethylsilanes, dimethicone crosspolymers, cyclomethicone,
gums, resins, fatty acid esters (esters of C.sub.6-C.sub.28 fatty
acids and C.sub.6-C.sub.28 fatty alcohols), glyceryl esters and
derivatives, fatty acid ester ethoxylates, alkyl ethoxylates,
C.sub.12-C.sub.28 fatty alcohols, C.sub.12-C.sub.28 fatty acids,
C.sub.12-C.sub.28 fatty alcohol ethers, propylene glycol esters and
derivatives, alkoxylated carboxylic acids, alkoxylated alcohols,
fatty alcohols, Guerbet alcohols, Guerbet Acids, Guerbet Esters,
and other cosmetically acceptable emollients.
[0075] Specific examples of suitable esters may include, but are
not limited to, cetyl palmitate, stearyl palmitate, cetyl stearate,
isopropyl laurate, isopropyl myristate, isopropyl palmitate, and
combinations thereof.
[0076] In addition to the oil, the oil phase of the oil-in-water
emulsion may further include one or more surfactants and/or
antioxidants. It should be recognized, however, that the oil phase
may not contain a surfactant/antioxidant without departing from the
scope of the present disclosure. Furthermore, due to the cavitation
produced with the ultrasonic treatment system, when surfactants are
used, less surfactant needs to be added. While described herein in
the oil phase, it should be recognized by one skilled in the art,
that one or more surfactants can be added to the water phase in
addition to or as an alternative to being added to the oil phase
without departing from the scope of the present disclosure.
[0077] As noted above, emulsions are typically prepared using
surfactants as the surfactants may contribute to the overall
cleansing, emulsification properties of the emulsion. Additionally,
the surfaces may be utilized to provide emulsions that are mild to
the skin and have a low likelihood of stripping essential oils from
the user, thereby creating irritation. Preferably, the oil phase
contains from about 0.1% (by total weight oil phase) to about 20%
(by total weight oil phase) surfactant. More suitably, the oil
phase contains from about 1% (by total weight oil phase) to about
15% (by total weight oil phase) surfactant and, even more suitably,
from about 2% (by total weight oil phase) to about 10% (by total
weight oil phase) surfactant.
[0078] Suitable surfactants can be nonionic surfactants, anionic
surfactants, cationic surfactants, amphoteric surfactants, and
combinations thereof. Suitable anionic surfactants include, for
example, alkyl sulfates, alkyl ether sulfates, alkyl aryl
sulfonates, alpha-olefin sulfonates, alkali metal or ammonium salts
of alkyl sulfates, alkali metal or ammonium salts of alkyl ether
sulfates, alkyl phosphates, silicone phosphates, alkyl glyceryl
sulfonates, alkyl sulfosuccinates, alkyl taurates, acyl taurates,
alkyl sarcosinates, acyl sarcosinates, sulfoacetates, alkyl
phosphate esters, mono alkyl succinates, monoalkyl maleates,
sulphoacetates, acyl isethionates, alkyl carboxylates, phosphate
esters, sulphosuccinates (e.g., sodium dioctylsulphosuccinate), and
combinations thereof. Specific examples of anionic surfactants
include sodium lauryl sulphate, sodium lauryl ether sulphate,
ammonium lauryl sulphosuccinate, ammonium lauryl sulphate, ammonium
lauryl ether sulphate, sodium dodecylbenzene sulphonate,
triethanolamine dodecylbenzene sulphonate, sodium cocoyl
isethionate, sodium lauroyl isethionate, sodium N-lauryl
sarcosinate, and combinations thereof.
[0079] Suitable cationic surfactants include, for example, alkyl
ammonium salts, polymeric ammonium salts, alkyl pyridinium salts,
aryl ammonium salts, alkyl aryl ammonium salts, silicone quaternary
ammonium compounds, and combinations thereof. Specific examples of
cationic surfactants include behenyltrimonium chloride,
stearlkonium chloride, distearalkonium chloride, chlorohexidine
diglutamate, polyhexamethylene biguanide (PHMB), cetyl pyridinium
chloride, benzammonium chloride, benzalkonium chloride, and
combinations thereof.
[0080] Suitable amphoteric surfactants include, for example,
betaines, alkylamido betaines, sulfobetaines, N-alkyl betaines,
sultaines, amphoacetates, amophodiacetates, imidazoline
carboxylates, sarcosinates, acylamphoglycinates, such as
cocamphocarboxyglycinates and acylamphopropionates, and
combinations thereof. Specific examples of amphoteric surfactants
include cocamidopropyl betaine, lauramidopropyl betaine,
meadowfoamamidopropyl betaine, sodium cocoyl sarcosinate, sodium
cocamphoacetate, disodium cocoamphodiacetate, ammonium cocoyl
sarcosinate, sodium cocoamphopropionate, and combinations
thereof.
[0081] Suitable zwitterionic surfactants include, for example,
alkyl amine oxides, silicone amine oxides, and combinations
thereof. Specific examples of suitable zwitterionic surfactants
include, for example,
4-[N,N-di(2-hydroxyethyl)-N-octadecylammonio]-butane-1-carboxylate,
S-[S-3-hydroxypropyl-S-hexadecylsulfonio]-3-hydroxypentane-1-sulfate,
3-[P,P-diethyl-P-3,6,9-trioxatetradexopcylphosphonio]-2-hydroxypropane-1--
phosphate,
3-[N,N-dipropyl-N-3-dodecoxy-2-hydroxypropylammonio]-propane-1--
phosphonate,
3-(N,N-dimethyl-N-hexadecylammonio)propane-1-sulfonate,
3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypropane-1-sulfonate,
4-[N,N-di(2-hydroxyethyl)-N-(2-hydroxydodecyl)ammonio]-butane-1-carboxyla-
te,
3-[S-ethyl-S-(3-dodecoxy-2-hydroxypropyl)sulfonio]-propane-1-phosphate-
, 3-[P,P-dimethyl-P-dodecylphosphonio]-propane-1-phosphonate,
5-[N,N-di(3-hydroxypropyl)-N-hexadecylammonio]-2-hydroxy-pentane-1-sulfat-
e, and combinations thereof.
[0082] Suitable non-ionic surfactants include, for example, mono-
and di-alkanolamides such as, for example, cocamide MEA and
cocamide DEA, amine oxides, alkyl polyglucosides, ethoxylated
silicones, ethoxylated alcohols, ethoxylated carboxylic acids,
ethoxylated amines, ethoxylated amides, ethoxylated alkylolamides,
ethoxylated alkylphenols, ethoxylated glyceryl esters, ethoxylated
sorbitan esters, ethoxylated phosphate esters, glycol stearate,
glyceryl stearate, and combinations thereof.
[0083] Additionally, the oil phase may include one or more
antioxidants. Suitable antioxidants include, for example, BHT, BHA,
Vitamin E, ceramide or ceramide derivatives, such as
glucosylceramides, acylceramide, bovine ceramides, sphingolipid E,
and combinations thereof.
[0084] Additionally, the oil-in-water emulsion includes a water
phase having from about 0.1% (by total weight of water phase) to
about 99% (by total weight of water phase) water, and a balance of
components including humectants, chelating agents, and
preservatives. Suitable humectants may include glycerin, glycerin
derivatives, sodium hyaluronate, betaine, amino acids,
glycosaminoglycans, honey, sorbitol, glycols, polyols, sugars,
hydrogenated starch hydrolysates, salts of PCA, lactic acid,
lactates, and urea. A particularly preferred humectant is
glycerin.
[0085] Chelating agents may act to enhance preservative efficacy,
and bind metals that could discolor the emulsion or hinder emulsion
stability. Suitable chelating agents include, for example, disodium
ethylenediamine tetraacetic acid (EDTA), commercially available
from the Dow Chemical Company under the name VERSENE Na.sub.2.
[0086] Additionally, as noted above, the water phase may include
one or more preservatives. Suitable preservatives include, for
example, the lower alkyl esters of para-hydroxybenzoates such as
methylparaben, propylparaben, isobutylparaben, and mixtures
thereof, benzyl alcohol, DMDM Hydantoin, and benzoic acid.
[0087] In one embodiment, the phases are mixed with one or more
thickeners to provide a thicker emulsion. Specifically, when the
emulsion is a hydrogel, basic pH adjusters, such as sodium
hydroxide, are preferably used to thicken the emulsion.
[0088] A variety of thickeners may be used in the phases described
herein. In one embodiment, the thickener may be a cellulosic
thickener or gum. Examples of suitable cellulosic or gum thickeners
include xanthan gum, agar, alginates, carrageenan, furcellaran,
guar, cationic guar, gum arabic, gum tragacanth, karaya gum, locust
bean gum, dextran, starch, modified starches, gellan gum,
carboxymethylcellulose, hydroxypropylcellulose,
hydroyethylcellulose, propylene glycol alginate, hydroxypropyl
guar, amylopectin, cellulose gum, chitosan, modified chitosan,
hydroxypropyl methylcellulose, microcrystalline cellulose, silica,
fumed silica, colloidal silica, dehydroxanthan gum, non-acrylic
based carbomers, and combinations thereof.
[0089] Alternately or in addition, the thickener may be an acrylic
based polymer. Non-limiting examples of suitable acrylic based
polymer thickeners include acrylates/C.sub.10-C.sub.30 alkyl
acrylate crosspolymers, certain carbomers, acrylates copolymers,
aminoacrylates copolymers, and combinations thereof. Examples of
commercially available acrylic based polymer thickeners include
Structure.RTM. Plus (National Starch & Chemical, Bridgewater,
N.J.), which is an acrylates/aminoacrylates/C.sub.10-30 alkyl
PEG-20 itaconate copolymer, Carbopol.RTM. Aqua SF-1 Polymer
(Noveon, Cleveland Ohio), which is an acrylates copolymer,
Pemulen.RTM. TR-1 and TR-2 and Carbopol.RTM. ETD 2020 (available
from Noveon), which are acrylates/C10-30 alkyl acrylates
crosspolymers, and the Carbopol.RTM. Ultrez series of polymers
(available from Noveon), which are carbomers.
[0090] In one embodiment, such when using a hydrogel as described
above, the phase (e.g., hydrogel) may be formulated using an
acid-sensitive thickener and/or a base-sensitive thickener. As the
names suggest, acid-sensitive thickeners are activated (i.e., swell
or "thicken") upon contact with an acidic agent, while
base-sensitive thickeners are activated upon contact with an
alkaline agent. An acid- or base-sensitive thickener may be
combined with other phase components prior to activation, and
activated by contact with an acidic or alkaline agent after the
acid- or base-sensitive thickener is dispersed throughout the
phase.
[0091] Examples of suitable acid-sensitive thickeners for use in
the phases include the Structure.RTM. Plus (National Starch &
Chemical, Bridgewater, N.J.) thickener, described above. The
acid-sensitive thickeners may be activated by contact with any of a
wide range of acidic agents including, for example, glycolic acid,
lactic acid, phosphoric acid, citric acid, other organic acids, and
similar acidic agents. Acid sensitive thickeners are generally
activated over a pH range of from about 3 to about 9, and more
typically over a pH range of from about 3 to about 7. The
Structure.RTM. Plus thickener is typically activated over a pH
range of from about 3 to about 9.
[0092] Examples of suitable base-sensitive thickeners include the
Carbopol.RTM. Aqua SF-1 Polymer (Noveon, Cleveland Ohio) thickener,
described above, as well as the Pemulen.RTM. TR-1 and TR-2
thickeners (available from Noveon), the Carbopol.RTM. ETD 2020
thickeners (available from Noveon), and the Carbopol.RTM. Ultrez
series of thickeners (available from Noveon), all described above,
and other carbomers and starches, and combinations thereof. The
base-sensitive thickeners may be activated by contact with any of a
wide range of alkaline agents including, for example, various metal
hydroxides and amines, and other similar alkaline agents.
Non-limiting examples of suitable metal hydroxides include
potassium hydroxide and sodium hydroxide. Non-limiting examples of
suitable amines include triethanolamine, diethanolamine,
monoethanolamine, tromethamine, aminomethylpropanol,
triisopropanolamine, diisopropanolamine,
tetrahydroxypropylethylenediamine, and PEG-15 cocoamine. Base
sensitive thickeners are generally activated over a pH range of
from about 5 to about 11, and more typically over a pH range of
from about 6 to about 11.
[0093] Although described above as using a thickener with a
hydrogel, it should be recognized by one skilled in the art that
the above thickeners can be used with any of the phases described
herein for preparing an emulsion.
[0094] In certain embodiments, one or more of the phases may
include two or more different types of thickeners. For instance,
the phases may include any combination of cellulosic thickeners,
gum thickeners, acid-sensitive thickeners, base-sensitive
thickeners, and/or acrylic based polymer thickeners.
[0095] While as disclosed herein in terms of mixing phases to
prepare the emulsions, it should it be recognized that one
emulsion, prepared using any method known in the art, can be mixed
with one or more additional phases to make a second emulsion using
the ultrasonic mixing system and the methods described herein
without departing from the scope of the present disclosure. For
example, in one embodiment, a water-in-oil-in-water emulsion is
prepared and is delivered via a first inlet port into the interior
space of the treatment chamber housing and a separate phase (i.e.,
a water phase, as described above) is delivered via a second inlet
port into the interior space of the treatment chamber housing. The
ultrasonic mixing system (and, more particularly, the waveguide
assembly), operating in the predetermined frequency as described
above, mixes the water-in-oil emulsion with the water phase to
produce a water-in-oil-in-water emulsion.
[0096] In one embodiment, one or more the phases are heated prior
to being delivered to the treatment chamber. Specifically, with
some emulsions, while some or all of the individual phases have a
relatively low viscosity (i.e., a viscosity below 100 cps), the
other phases or the resulting-emulsion that is prepared from the
phases has a high viscosity (i.e., a viscosity greater than 100
cps), which can result in clumping of the emulsion and clogging of
the outlet port of the treatment chamber. For example, many
water-in-oil emulsions can suffer from clumping during mixing. In
these types of emulsions, the water and/or oil phases are typically
heated to a temperature of approximately 40.degree. C. or higher
prior to being mixed. Suitably, one or more of the phases can be
heated to a temperature of from about 70.degree. C. to about
100.degree. C. prior to being delivered to the treatment chamber
via the inlet ports.
[0097] Typically, the oil phase and water phase are delivered to
the treatment chamber at a flow rate of from about 1 gram per
minute to about 100,000 grams per minute. In one embodiment, the
oil phase and water phase have different flow rates. By way of
example, in one particular embodiment, the oil phase can be
delivered via the first inlet port at a flow rate of from about 1
gram per minute to about 10,000 grams per minute, and the water
phase can be delivered via the second inlet port at a flow rate of
from about 1 gram per minute to about 10,000 grams per minute. In
an alternative embodiment, the oil phase and water phase are
delivered into the interior of the treatment chamber at equal flow
rates.
[0098] In accordance with the above embodiment, as the water and
oil phases continue to flow upward within the chamber, the
waveguide assembly, and more particularly the horn assembly, is
driven by the drive system to vibrate at a predetermined ultrasonic
frequency to mix the phases, thereby preparing the emulsion.
Specifically, in response to ultrasonic excitation of the horn, the
agitating members that extend outward from the outer surface of the
horn dynamically flex/bend relative to the horn, or displace
transversely (depending on the longitudinal position of the
agitating member relative to the nodal region of the horn).
[0099] The phases continuously flow longitudinally along the flow
path between the horn assembly and the inner surface of the housing
sidewall so that the ultrasonic vibration and the dynamic motion of
the agitating members cause cavitation in the phases to further
facilitate agitation. The baffle members disrupt the longitudinal
flow of liquid along the inner surface of the housing sidewall and
repeatedly direct the flow transversely inward to flow over the
vibrating agitating members.
[0100] As the mixed emulsion flows longitudinally downstream past
the terminal end of the waveguide assembly, an initial back mixing
of the emulsion also occurs as a result of the dynamic motion of
the agitating member at or adjacent the terminal end of the horn.
Further downstream flow of the emulsion results in the agitated
liquid providing a more uniform mixture of the phases prior to
exiting the treatment chamber via the outlet port.
[0101] The present disclosure is illustrated by the following
examples which are merely for the purpose of illustration and are
not to be regarded as limiting the scope of the disclosure or
manner in which it may be practiced.
EXAMPLE 1
[0102] In this Example, the ability of the ultrasonic mixing system
of the present disclosure to mix an oil phase and aqueous liquid
phase to form an oil-in-water type emulsion was analyzed.
Specifically, the ability of the ultrasonic mixing system to mix
dispersions of mineral oil into a diluted wet wipes solution was
analyzed.
[0103] The diluted wet wipe solution included 4.153% (by weight)
KIMSPEC AVE.RTM. (commercially available from Rhodia, Inc.,
Cranbury, N.J.) and 95.848% (by weight) purified water. The
solution was prepared by mixing the KIMSPEC AVE.RTM. into water
using a propeller mixer, available from IKA.RTM. EUROSTAR, IKA
Works Co., Wilmington, N.C.), rotating at a speed of about 540
revolutions per minute (rpm). Four separate samples of the diluted
wet wipe solution were prepared. The solution for each sample was
delivered to a first inlet port of the ultrasonic mixing system of
FIG. 1.
[0104] Additionally, a flow of mineral oil, available as PenrecoO
Drakeol.RTM. LT mineral oil N.F. from Penreco Co., The Woodlands,
Tex.) was delivered to a second inlet port of the ultrasonic mixing
system shown in FIG. 1. The weight ratio of mineral oil to wet wipe
solution was 1:199. Three different flow rates of the emulsion
samples were used for samples A, B, and C (4000 grams per minute,
2000 grams per minute, and 1000 grams per minute, respectively).
Additionally, one wet wipe solution (Sample D) was produced by
adding 1% (by total weight solution) of surfactant, commercially
available as Solubilisant LRI from LCW, South Plainfield, N.J.), so
the weight ratio of oil to surfactant to wet wipe solution was
1:2:197. The flow rate of Sample D was 1000 grams per minute.
[0105] The ultrasonic mixing system was then ultrasonically
activated using the ultrasonic drive system at a frequency of 20
kHz. After mixing in the treatment chamber, the wet wipe solutions
(now having the mineral oil incorporated therein) exited the
treatment chamber via the outlet port. The physical appearances of
the emulsions observed are summarized in Table 1. The size and
distribution of oil droplets within the emulsions so prepared were
analyzed using the Laser Light Scattering Method by Micromeritics
Analytical Services (Norcross, Ga.) after thirteen days of the
experiment. The data on mean particle size and size distribution of
the mineral oil droplets in the wet wipe solutions are shown in
Table 2.
TABLE-US-00001 TABLE 1 Flow Rate of Mineral Oil Wet Wipe into
Mixing Mixing Visual Appearance of Solution System Time Wet Wipe
Solution Sample (g/min) (minutes) Containing Mineral Oil A 20 0.5
Translucent, milk-like, no visible droplets B 10 1 Milk-like; less
transparent than A; no visible droplets C 5 2 Milk-like; not
transparent; no visible droplets D 5 2 Milk-like; not transparent;
no visible droplets
TABLE-US-00002 TABLE 2 Mean Wet Wipe particulate Diameter Solution
diameter Diameter 50% finer Diameter Sample (.mu.m) 90% finer
(Median) 10% finer A 1.862 3.368 1.381 0.576 B 1.110 2.266 0.655
0.190 C 0.654 1.375 0.379 0.142 D 0.767 1.536 0.510 0.166
[0106] As shown in Table 2, the wet wipe solutions C and D, which
were mixed in the ultrasonic mixing system for two minutes, had
smaller particle sizes of mineral oil droplets, showing a better
dispersion of mineral oil within the aqueous wet wipe solution.
[0107] Additionally, after 40 days, the appearances of the wet wipe
solution samples were analyzed visually. All wet wipe solutions
contained a thin creamy layer on top, but the layer was miscible
with the remaining portion of the sample with slight agitation.
EXAMPLE 2
[0108] In this Example, the ultrasonic mixing system of the present
disclosure was used to emulsify an oil phase into a water phase to
produce an oil-in-water emulsion. The ability of the ultrasonic
mixing system to prepare a stable oil-in-water emulsion was
analyzed and compared to an oil-in-water emulsion prepared using a
traditional cold mix procedure as described above.
[0109] Three oil-in-water emulsions were prepared. Specifically,
the oil-in-water emulsions were prepared by mixing 1 part mineral
oil (available as PenrecoO DrakeolO LT mineral oil N.F. from
Penreco Co., The Woodlands, Tex.)) to 199 parts water for a mixing
period of approximately 2 minutes. The first emulsion sample
(Sample 1) was prepared using a propeller mixer (IKA.RTM. EUROSTAR,
IKA Works, Co., Wilmington, N.C.) and using the standard cold mix
batch procedure.
[0110] The other two oil-in-water emulsions (Samples 2 and 3) were
prepared in the ultrasonic mixing system of FIG. 1. Specifically,
to produce the oil-in-water emulsion of Sample 2 with the
ultrasonic mixing system, the oil phase was added into the first
inlet port at a flow rate of 20 grams per minute and the water
phase was added into the second inlet port at a flow rate of 3980
grams per minute. The oil phase and water phase were mixed in the
chamber for a total of 30 seconds.
[0111] Sample 3 was prepared by additionally mixing in a surfactant
(Solubilisant LRI, LCW, South Plainfield, N.J.) with the oil phase
in a weight ratio of surfactant to oil of 1:1. The mixed oil phase
(including the surfactant) was then added at a flow rate of 24
grams per minute into the first inlet port of the ultrasonic mixing
system of FIG. 1. The water phase was added into the second inlet
port at a flow rate of 3980 grams per minute and mixed with the oil
phase. The oil and surfactant of the oil phase and water of the
water phase were added at a weight ratio of 0.3:0.3:99.4. Once the
emulsions were formed, the emulsions were visually inspected and
stored in two separate containers. After 30 hours, the containers
were visually inspected. The results are shown in Table 3.
TABLE-US-00003 TABLE 3 Visual Observation Visual of Physical
Observation Appearance of Physical of Emulsion Appearance Mixing
Immediately of Emulsion Mixing Time After after 30 Sample Method
(min) Mixing hours 1 Hand mixer 2.0 Milk-like Oil phase formulation
completely for 1-2 separated minutes from water phase 2 Ultrasonic
0.5 Stable Milk-like mixing milk-like emulsion system emulsion with
a few 1 mm with no diameter droplets oil droplets on top; separated
completely after 3 days 3 Ultrasonic 0.5 Milk-like Milk-like mixing
emulsion emulsion system without without visible oil visible oil
droplets droplets
[0112] As shown in Table 3, both of the emulsions produced using
the ultrasonic mixing system remained stable until 30 hours after
exiting the chamber while the emulsion prepare in the batch process
separated within a couple minutes. While Sample 2 finally separated
completely after about 3 days, the emulsion prepared using the oil
phase that comprised SOLUBILISANT LRI remained stable for 40
days.
[0113] The oil droplets from the batch-produced oil-in-water
emulsion were sized from several micrometers to several hundreds of
micrometers. For the two emulsions produced using the ultrasonic
mixing system, after five days of aging) the oil droplets ranged
from sub-micrometers in size to a couple of micrometers.
[0114] When introducing elements of the present disclosure or
preferred embodiments thereof, the articles "a", "an", "the", and
"said" are intended to mean that there are one or more of the
elements. The terms "comprising", "including", and "having" are
intended to be inclusive and mean that there may be additional
elements other than the listed elements.
[0115] As various changes could be made in the above constructions
and methods without departing from the scope of the invention, it
is intended that all matter contained in the above description and
shown in the accompanying drawings shall be interpreted as
illustrative and not in a limiting sense.
* * * * *