Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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APPARATUS FOR DISTRIBUTION OF A GAS INTO A BODY OF LIQUID
FIELD OF THE INVENTION
The present invention relates to an apparatus for aerating and mixing bodies
of liquid, and
specifically to an improved submersible mixer and associated disk which
distribute aspirated
gas into the liquid in a large radial pattern in the form of fine bubbles for
improved gas transfer
rates into the liquid.
BACKGROUND OF THE INVENTION
Submersible aeration and mixing devices of various configurations have been
developed in the
past, ranging from simple static devices to complex mechanical machines. All
aeration and
mixing devices attempt to drive oxygen (usually the form of air) into the body
of liquid and to mix
the effluent to keep solids in suspension and to distribute the oxygen into
the body of liquid.
They are commonly used in industrial applications, including in waste water
treatment plants to
mix and aerate the waste liquids to facilitate digestion of waste in those
liquids. It is important in
achieving maximum efficiency of the digestion process to provide significant
mixing of the waste
water liquid and solids contained therein as well as to introduce gasses into
the waste water in a
manner which facilitates the mixing of the gasses with the waste water.
Preferably the mixing
device not only causes significant mixing of the liquids and solids, but also
introduces the gases
into the liquid in fine bubbles to assist in the absorption process with the
liquid. The gasses
suspended in the liquid is important as oxygen in the suspended gasses (such
as air) is used by
bacteria and other microscopic organisms in the process of digestion of the
waste solids and
decomposition of organic matter in the water in order to clean the water.
Many diffused aeration and mixing systems are available and range from course
bubble
systems to fine bubble systems. Fine bubble systems offer the highest oxygen
transfer rates in
clean water. However in operation they are rarely used in a clean water
environment. These
types of diffusers can quickly foul or become clogged in process conditions of
unclean water
which lower their oxygen transfer rates. Diffused aeration systems require a
system of pipes
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and diffusers mounted in the aeration basin of the tank as well as large
blowers or compressors
housed above ground in a purpose built facility. When diffusers foul or fail
the entire aeration
basin must be emptied in order for the diffusers and/or piping to be replaced
or repaired.
Diffused aeration systems provide some mixing as the diffused gas travels from
the diffuser
through the liquid to the surface.
Mechanical surface aerators use electric motors to drive a propeller which is
located at or very
near the surface. These devices lift liquid and forces it against a diffuser
plate which creates a
360 Degree spray pattern designed to facilitate gas transfer as the water
flies through the air
and re-enters the liquid. Compared to diffused aerations systems, surface
aerators have much
lower gas transfer rates and are very poor mixers. Often installed in lagoon
systems surface
aerators can be serviced from the surface and can be re-configured without
draining the
aeration basin.
Self aspirating turbine aerators use a submerged impeller to inject gas
(usually air) into a body
of liquid while simultaneously mixing the liquid with the gas. Coupled to a
hollow shaft, the self
aspirating turbine develops a strong vacuum behind each impeller vane as the
impeller is
rotated at high speeds (such as 1200 RPM). This vacuum draws air down the
hollow shaft and
ejects it from the spinning impeller at very high velocities. As the air exits
the impeller it is
subjected to large hydraulic forces which shear the gas into smaller bubbles
and the rotation of
the impeller creates radial flows which distribute the gas into the body of
liquid surrounding the
submerged impeller.
However one problem with these types of aerators in practice is the difficulty
in controlling the
flow of gas from the impeller. These types of devices have a tendency to flood
at the high
operating speeds required to create a vacuum strong enough to draw gas below
the surface of
the liquid. Essentially the volume of gas being introduced by the device
quickly overcomes the
mixing ability of the device and the gas very quickly displaces the
surrounding liquid. Within
seconds of reaching operating speeds submerged turbine aerators can often
flood with gas
which prevents radial distribution of gas into the surrounding liquid. There
is more gas around
the impeller than liquid. Gas continues to be introduced into the liquid at
high rates due to the
vacuum and can form a narrow vertical stream with a relatively small area of
influence and
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minimal mixing effectiveness. Instead of distributing the gas radially into
the liquid the gas
travels straight up in the liquid in a column with a small diameter cross-
sectional area and with
very turbulent stream of gas. As new gas is introduced by the impeller it
coalesces with gas
already released from the device forming very large fast moving bubbles which
are inefficient for
gas transfer or mixing in the liquid. This rapid rising column of gas breaks
the surface with
violent bubbling in close proximity to the rotating hollow shaft.
This causes the efficiency of these types of turbine aerators to be reduced
significantly and
reduces the usefulness of these types of turbine aerators.
Drawing liquid to the aspirating propeller and directing the flow of gas away
is critical to
minimizing impeller flooding and to maximizing the gas transfer capabilities
of the device.
As a consequence there is a need for an improved aspirating turbine aerator in
which the gas
can be better controlled in a manner that improves the efficiency of the
aspirating turbine
aerator in creating fine bubbles of gas exiting the aerator and in mixing
those bubbles more
efficiently with the liquid.
SUMMARY OF THE INVENTION
This invention provides a submersible, slotted, rotary disk which, when
coupled with a mixer
(including an aspirating turbine aerator), improves the dispersal of the air
from the mixer by
breaking up the gas into finer bubbles as the gas contacts the disk after
leaving the mixer and
rising in the liquid. The combination of disk and mixer improves gas transfer
rates into the liquid
by increasing shear thereby creating finer bubbles of gas and strong radial
distribution channels
in close proximity to the release point of aspirated gas from the mixer.
In one aspect of the present invention a thin rotating disk with slotted vents
is coupled above the
aspirating propeller for rotation therewith. The disk is designed to contact
the gas exiting from
the propeller as the gas moves upwardly from the propeler. Liquid from beneath
the propeller
passes the gas vents of the rapidly spinning propeller which entrains
aspirated gas in the liquid
and directs it at the slots of the larger diameter rotating disk above. The
disk is spinning at the
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same speed as the propeller and gas entering the slots from the bottom of the
disk is rapidly
sheared into smaller bubbles as the gas exits the top of the slots.
Simultaneously the rotation of
the disk in the liquid creates strong radial mixing currents which work to
propel the liquid radially
away from device.
This radial distribution redirects the primary axial flow from the aspirating
propeller and improves
mixing, reduces bubble size and vastly improves gas distribution into a liquid
when compared to
devices without such a disk.
A balance between the volume of gas being released and mixing is important to
providing an
efficient method for aerating liquids. With this device the balance can be
adjusted to suit
different applications. Adjustment can be made as needed by changing the
operating speed
(RPM) of the device, disk diameter, gas flow rate and submergence level of the
device to obtain
optimal mixing of the gas into the liquid.
In an embodiment of the invention a mixing system for mixing and distributing
a gas into a liquid
includes a drive shaft connectable to a motor for rotating the drive shaft; a
rotatable mixer
connected to the drive shaft for mixing the gas and liquid together, the mixer
includes a plurality
of blades having an upper pitched surface to direct liquid upwardly from the
blades, each blade
having a passageway having an inlet and an outlet through which gas may flow
from the inlet to
the outlet and radially outwardly into the liquid; a conduit associated with
the drive shaft
connected to the inlet for directing gas through the conduit into the inlet;
and a rotatable disk
connected to the drive shaft positioned above the mixer, the disk comprising a
plurality of
openings positioned with respect to the mixer such that gas exiting the outlet
and rising in the
liquid may be contacted by and pass through one or more openings to physically
sheer the gas
into smaller bubbles.
In further embodiments the conduit may include a hollow section in the drive
shaft. The mixer,
when rotated, may create a suctional force on the gas in the passageway to
cause the gas in
the passageway to be drawn out through the outlet. The plurality of opening
may be position in
relation to the mixer such that at least a portion of the openings are
oriented above, and slightly
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radially outward from, the outlet. The gas may exit from the outlet at an
exhaust region of the
liquid and the openings may be position so that they are above the exhaust
region.
In other embodiments the disk may be circular and extend beyond the outer
periphery of the
mixer with the openings located adjacent the outer periphery of the disk in
concentric alignment.
The outside diameter of the disk may be approximately one point four times the
outside
diameter of the mixer. The openings may include longitudinal slots extending
radially from the
axis of the disk with approximately the same width as the thickness of the
disk.
In alternate embodiments the disk and mixer may rotate at the same speed. The
disk may
define a plane that is perpendicular to the drive shaft. The blades may have
an outer end and
the outlet may be located at the outer end. The blades may have a trailing
side and wherein the
outlet is at the trailing side. The blades may have an outer end with the
outlet located at the
outer end and the blades may also have a trailing side with a second outlet
located at the
trailing side.
In other embodiments the plurality of openings may be approximately equally
spaced from each
other in a generally circular array. The plurality of openings may be radially
spaced away an
equal distance from the centre of the disk.
In a further embodiment of the invention a method of aspirating a body of
liquid with a gas
includes the steps of: (a) immersing a rotatable mixer and disk combination
into the liquid, the
mixer including: (i) at least one blade having an upper pitched surface which,
when rotated,
drives liquid upwardly from the blade and a passageway having an inlet and an
outlet; and
(ii) the disk positioned above the mixer and comprising a plurality of
openings positioned with
respect to the mixer such that gas exiting the outlet and rising in the liquid
may be contacted by
and pass through one or more openings to physically break up the gas into
finer bubbles;
(b) connecting a source of gas to the inlet; and (c) rotating the mixer and
disk such that gas
passes from the source of gas into the inlet, through the passageway and out
the outlet into the
liquid such that the gas is driven radially outwardly from the mixer and rises
due to buoyancy
forces into the openings.
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DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of the rotatable disc of the mixing system of a
preferred embodiment of
the invention;
FIG. 2. is a side view of the rotatable disc of Figure 1;
FIG. 3 is a side view of the rotatable disc of Figure 1 taken along 3 -3 of
Figure 1;
FIG. 4 is a perspective view of the rotatable disc of Figure 1;
Fig. 5 is a side view of the mixing system of a preferred embodiment of the
invention;
FIG. 6 is a bottom view of the mixing system of Figure 5;
FIG. 7 is a bottom perspective view of the mixing system of Figure 5; and
FIG 8 is a perspective view of the mixing system of Figure 5 attached to a
drive shaft and motor.
DETAILED DESCRIPTION
Referring to Figures 1 through 4, a rotatable disk 12 is used as a part of a
mixing system for
mixing in and distributing a gas into a liquid. Disk 12 has a circular
circumference with axis of
rotation 14 at the centre of disk 12.
A plurality of openings 16 are positioned adjacent outer circumference 18.
Openings 16 are
generally elongated and capsule shaped extending radially from axis 14.
Openings 16 are in
concentric alignment with one another about axis 14. Opposed sides of openings
16 are
parallel with one another and are perpendicular with the upper and lower faces
20 and 22 of
disk 12.
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In the preferred embodiment openings 16 are approximately the same width as
the thickness of
disk 12, that is as compared to the distance between upper face 20 and lower
face 22. As well,
in a preferred system, the length of each slot is approximately .125 times the
outer
circumference of disk 12. Openings 16 are approximately equally spaced from
each other in a
generally circular array.
Figures 5, 6 and 7 depict disk 12 when in use as a part of the mixing system
for mixing and
distributing gas into a liquid 24 which is comprised of disk 12, drive shaft
26 and rotatable
mixer 28. Mixer 28 may be comprised of a propeller similar to that in my co-
pending application
number 11/978,005. Mixer 28 is designed to mix a gas and liquid together to
facilitate mixing
and distributing gas into the liquid by mixing system 24. Mixer 28 and disc 12
are attached to
shaft 26 in a manner which imparts rotational motion on disc 12 and mixer 28
on rotation of
shaft 26. As mixer is designed to rotate in the direction of arrow 34,
driveshaft 26 will also be
driven by a motor system 36 (Fig. 8) in the direction of arrow 34. The
rotation of driveshaft 26 in
this direction will also cause disc 12 to be rotated in the direction of arrow
34.
As seen in Figure 5 drive shaft 26 is integrally connected to mixer 28 such
that mixer 28 rotate
on rotation of drive shaft 26. Disc 12 is connected to driveshaft 26 as
driveshaft 26 extends
through central opening 30 (Fig. 1). Disk 12 defines a plane that is
perpendicular to the drive
shaft 26. Disc 12 is located above mixer 28 and is spaced apart from mixer 28
a sufficient
distance 32 to enable gas exiting from mixer 28 to form bubbles prior to
contacting disc 12 as
the gas rises from mixer 28 due to buoyancy forces on the gas in the liquid.
In the preferred
embodiment the distance 32 between mixer 28 and disc 12 is about between 20
and 60
millimetres.
As seen best in Figure 6, mixer 28 includes four lateral blades 38 arranged
symmetrically about
axis 14 as seen best in Figure 3. When viewed from the side as in Figure 5,
blades 38 are
generally perpendicular to axis 14, with some modification as discussed below.
Each blade 38 is comprised of upper surface or pressure side 40, lower surface
or suction
side 42, root section 44, tip 46, leading face 48 and trailing face 50.
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Referring to Figure 6, both leading face 48 and trailing face 50 are curved
rearwardly in a
direction away from the direction of rotation 34. It can be seen that the
degree of curvature of
leading face 48 is less than a degree of curvature of trialing face 50. This
causes the distance
between face 48 and face 50 to be less near root section 44, as compared to
tip 46. This
creates a relatively bulbous tip 46 of blade 38.
Leading face 48 includes outer extension 52 which extends outwardly beyond tip
46. Extension
52 is an optional component and provides additional impingement against the
liquid and the gas
exiting from openings 60 and 62, as discussed below.
Referring to Figure 5, upper surface (pressure side) 40 is angled upwardly
from a plane
perpendicular to axis 14. This orientation of surface 40 means that upper
surface (pressure
side) 40 is lower adjacent leading face 48 as compared to trailing face 50.
The preferred
upward angle between the plane perpendicular to axis 14 and the plane defined
by upper
surface (pressure side) 26 is about 1.30 degrees. Although a range of upward
angles between
about 1 and 10 degrees is also suitable.
Lower surface (suction side) 42 is also angled upwardly from the plane
perpendicular to axis 14.
This orientation of surface 42 means that lower surface (suction side) 42
adjacent leading
face 48 is lower than lower surface (suction side) 42 adjacent trailing face
50. The preferred
upward angle between the plane perpendicular to axis 14 and the plane defined
by lower
surface (suction side) 42 is about 6.95 degrees. Although a range of upward
angles between
about 5 and 17 degrees is also suitable. In a preferred embodiment the upward
angle of upper
surface (pressure side) 40 is less than the upward angle of lower surface
(suction side) 42.
In this embodiment the said angle of lower surface (suction side) 42 is
greater than the said
angle of upper surface (pressure side) 40 which is a preferred orientation.
The orientation of upper surface (pressure side) 40 and lower surface (suction
side) 42 in this
manner, with the upward angle of upper surface (pressure side) 40 less than
the upward angle
of lower surface (suction side) 42 , means that the distance between upper
surface (pressure
side) 40 and lower surface (suction side) 42 is less adjacent trailing face 50
as compared to the
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distance between upper surface (pressure side) 40 and lower surface (suction
side) 42 adjacent
leading face 48.
Referring to Figures 5 and 6, each of blades 38 is hollow with chamber 54
extending Into and
connecting with each blade 38 of mixer 28. This is shown by blade 56 of in
Figure 6, which has
lower surface 42 removed for ease of reference. It should be understood that
in use blade 56
includes a lower surface 42 in the same manner as the other blades 38 of
Figure 6. Shaft 26 is
hollow forming conduit 58 therein extending the length of shaft 26. The lower
end of conduit 58
connects with each chamber 54 of blades 38 at the inner or axial end of blades
38 (as best
depicted with respect to blade 56). Upper end of Shaft 26 is intended to
extend above the liquid
to permit gas (such as air from the atmosphere) to be drawn into conduit 58,
and through
conduit 58 into each chamber 54 of blades 38.
Each blade 38 includes two openings connected to chamber 54, a rearward
opening 60 and an
outer opening 62. Opening 60 is positioned within trailing face 50 and faces
rearwardly toward
the leading face of a blade 38 of mixer 28 to the rear of blade 38. Opening 60
is rectangular in
shape positioned within trailing face 50 with a root section adjacent root
section 44 of blade 38.
Opening 62 is positioned within tip 46 facing outwardly from axis 14. Opening
62 is positioned
within tip 46 adjacent leading face 48 at one end and with its opposite end
near trailing face 50.
Opening 62 is generally rectangular in shape although due to the angling of
upper and lower
surface (suction side)s 40 and 42 as discussed above, opening 62 is somewhat
wider at its end
adjacent leading face 48 as compared to its opposite end.
Referring to Figure 6, disk 12 is dimensioned with respect to mixer 28 such
that tip 46 and outer
opening 62 are positioned generally in vertical alignment with the innermost
region of
openings 16 of disk 12. Disk 12 is thereby positioned with respect to mixer 28
such that gas
exiting opening 62 from chamber 54 may rise in the liquid to be contacted by
one or more
openings 16 with a portion of the gas pass through openings 16. The gas is
thereby physically
sheared into smaller bubbles. This facilitates the aeration of the liquid by
the gas exiting mixer
28.
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Similarly, gas exiting opening 60 also rises upwardly due to buoyancy forces
and contacts lower
face 22 of disk 12. Because disk 12 is rotating, centrifugal forces cause that
gas to move
outwardly along lower face 22 until it is contacted by openings 16, thereby
providing similar
physical shearing of that gas into smaller bubbles as it contacts and/or
passes through openings
16.
Operation
Mixing system 24 is designed to be immersed in a liquid to provide both mixing
of the liquid and
aerating of the liquid (that is, the introducing air or other gas into the
liquid). One useful
application is in the mixing and aeration of municipal waste tanks to enhance
the breakdown of
organic waste by bacteria which need the oxygen in the introduced air to
properly digest that
material and to multiply. Although the mixing system 24 can be used to
introduce and mix
various gases (or other fluids such as liquids) in a liquid in which the
mixing system 24 is
submerged.
As discussed above, mixing system 24 is designed to be rotated in the
direction of arrow 34. A
suitable motor system 36 (Figure 8) is connected to mixing system 24 by means
of a drive shaft
26 in order to impart that rotational motion on mixing system 24. The drive
shaft 26 is hollow to
form conduit 58 which is connected to chamber 54.
Upon rotation of mixing system 24 by motor system 36, gas (in the case of
aeration, the gas
may be air) is either forced down or drawn down conduit 58 of drive shaft 26
into chamber 54.
Due to the centrifugal forces on the gas within chamber 54 of each blade 38 of
mixing
system 24 as it rotates, the gas in chambers 54 of each blade 38 is forced out
of openings 60
and 62. Gas exiting chamber 54 through opening 60 exits rearwardly striking
the leading face
48 of blade 38 (including optional extension 52 if utilised) of the next
rearward blade 38. That
leading face 48 (and optional extension 52) contacts the gas exiting opening
60 which splits the
gas into fine bubbles to assist in dispersing the gas in the liquid in which
mixing system 24 is
immersed. Gas exiting chamber 54 through opening 62 exits radially and
rearwardly also
striking the leading face 48 of blade 38 (including optional extension 52 if
utilised) of the next
rearward blade 38. That leading face 48 (and optional extension 52) contacts
the gas exiting
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opening 62 which splits the gas into fine bubbles to assist in dispersing the
gas in the liquid in
which mixing system 24 is immersed.
However at times the gas leaving mixer 28 does not form fine bubbles in this
manner. Instead a
steady stream of gas may flow upwardly. This is unsuitable for enhancing
aeration of the liquid
as most of the gas is lost at the surface of the liquid rather than being
maintained in the liquid to
facilitate digestion. Applicants mixing system 24 provides an advantage with
the adoption of
disc 12 and its location and orientation with respect to mixer 28.
Gas exiting chamber 54 through opening 62 moves outwardly into the liquid,
generally in a
radial direction perpendicular to axis 14 to enter an exhaust region generally
radially adjacent to
tips 46 of blades 38. Buoyancy forces and physical contact with the angled
upper surface 40
acting on the gas entering the exhaust region cause the gas to rise and strike
disc 12. Because
openings 16 are positioned vertically above the exhaust region, at least a
portion of the gas will
contact openings 16 and either travel through openings 16 or otherwise be
contacted by
openings 16. This is further facilitated by openings 16 being positioned
longitudinally and
radially from the axis of rotation of the disk and equally spaced from each
other in a generally
circular array. This physical contact acts to break up the gas into finer
bubbles which enhances
the aeration of the liquid with the gas.
Gas exiting through openings 62 also rise upwardly due to buoyancy forces, and
due to physical
contact with the angled upper surface 40, strike lower surface 42 of disc 12.
As disc 12 is
rotating centrifugal forces cause that gas to move radially outwardly along
surface 42 with at
least a portion of the gas contacting openings 16 and either travelling
through openings 16 or
otherwise be contacted by openings 16. The gas leaving opening 62 is thereby
also physically
sheered into smaller bubbles to facilitate aeration of the liquid with that
gas.
As mixer 28 rotates in the direction of arrow 34, the angle of upper surface
(pressure side) 40
creates an additional physical contact with the gas as well as an upward
movement of the liquid,
in addition to the contact caused by leading face 48. The contact of upper
surface (pressure
side) 40 with the gas causes the gas to flow axially in a direction generally
parallel with that of
axis 14, in an upward direction.
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The angle of lower surface (suction side) 42 creates a suction beneath blades
38 as mixer 28 is
rotated in the direction of arrow 34, which sucks the gas along lower surface
(suction side) 28 in
a direction from an area adjacent leading face 48 toward and past trailing
face 50 which also
causes the gas to move generally axially in a direction perpendicular to axis
14 and upwardly
from mixer 28. This also provides thrust which makes mixer 28 run more
smoothly.
The upward movement of the liquid past mixer 28 further directs the gas to
contact openings 16
of disc 12 to physically sheer the gas into smaller bubbles to facilitate
aeration.
The angles of upper surface (pressure side) 26 and lower surface (suction
side) 28 cause an
upward movement of liquid as mixer 28 is rotated. In addition centrifugal
forces cause both
liquid and exiting gas to move radially from mixer 28. This simultaneous
lateral mixing (i.e.
radial mixing) and upward mixing (i.e. axial mixing) provides significant
benefits as compared to
propellers which mix liquid in only one direction, either radially or axially.
Mixing is further
enhanced due to the positioning of opening 60 with respect to leading face 48
of the following
blade 38 which causes gas leaving opening 60 to be struck by leading face 48
to further
enhance the mixing process of gas in the liquid further enhancing the
operation of mixer 28 to
aerate that liquid.
Also beneficial to the mixing of the liquid and mixing of the liquid with the
gas is the curvature of
leading face 34, which is curved rearwardly in a direction away from the
direction of rotation 34.
Furthermore, blades 38 at their tip are wider than at their root section to
form a bulbous tip. As
mixer 28 turns in the direction of arrow 34, the liquid accelerates across
leading edge 34
creating an area of high pressure in front of and on top of each blade 38. The
curvature of
leading edge 34 accelerates the liquid along leading edge 34 outwardly toward
extension 52.
Liquid is also accelerated across upper surface (pressure side) 26 and lower
surface (suction
side) 28 of each blade 38 toward tip 46 of each blade 38.
This high pressure stream of liquid accelerates across openings 60 and 62 to
create a low or
negative pressure area within chamber 54. That negative pressure draws gas
down the hollow
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shaft into chamber 54 and the gas is then flung outwardly by centrifugal force
due to the rotation
of mixer 28.
It should further be noted that the combination of the perpendicular,
relatively blunt,
configuration of leading face 34, the generally bulbous tip 46 of blades 38
and the curvature
rearwardly of leading face 48 cause the liquid in which the propeller is
submerged to travel
across blades 38 and along leading face 48 in a manner which creates streams
of higher
pressure of the liquid in front of and on top of each blade 38. The higher
pressure streams of
liquid flows past openings 60 and 62 as mixer 28 is rotated in the direction
of arrow 34. This
creates a region of lower pressure within chamber 54 which draws the gas down
the hollow
shaft (not shown) through chamber 54 and out openings 60 and 62 into the
liquid. This
facilitates the dispersing and mixing of the gas with the liquid.
ALTERNATIVES
While this invention has been described as a having a preferred embodiment, it
is understood
that it is capable of further modifications, uses and/or adaptations of the
invention following in
general the principle of the invention and including such departures from the
present disclosure
has come within the known or customary practice in the art to which the
invention pertains and
as may be applied to the central features herein before set forth, and fall
within the scope of the
invention and of the limits of the appended claims. As will be apparent to
those skilled in the art
to which the invention is addressed, the present invention may be embodied in
forms other than
those specifically disclosed above, without departing from the spirit or
essential characteristics
of the invention. The particular embodiments of the invention described above
and the
particular details of the processes described are therefore to be considered
in all respects as
illustrative or exemplary only and not restrictive. The scope of the present
invention is as set
forth in the complete disclosure rather than being limited to the examples set
forth in the
foregoing description.
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