Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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MOBILE VORTEX SHIELD
TECHNICAL FIELD
The present invention relates to an apparatus used during an
aeration process. More particularity, the present invention relates to
an apparatus for preventing vortices in an aerated substance.
BACKGROUND OF THE INVENTION
In biological purification of waste waters which contain organic
solids, sediments are formed which are so firm thflt anaerobic zones
occur within them. This leads to the creation of offensive odors and
sedimentation. Dissolved oxygen is required to prevent the formation
of these offensi~e odors and to biologically break down the organic
matter within the water. Moreover, a certain amount of dissolved
oxygen is required to sustain various aquatic organisms. Increasing the
dissolved oxygen content of other substances, such as sludge, is slso
necessary.
Aeration apparatus are used to increase the dissolved oxygen
content of the treated substance and thereby purify it. One type of
aeration apparatus is a propeller aspirator aerator. These devices use
an electric motor driven rotating propeller disposed below the surface
of the substance being treated. The propeller draws in atmospheric air
from an intake port through a draft tube and discharges it into the
substance.
As is apt to happen with subsurface propeller-type devices,
vortices are created. In the context of an aeration apparatus, vortices
are undesirable as they decrease the speed and efficiency of operation.
To combat this problem vortex shields have been developed for aera-
tors. These shields prevent the formation of vortices adjacent the
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propeller in the substance in which the propeller is driven. In prior
art embodiments of vortex shields, the shield is rigidly affixed to the
aerator so as to reside, in part, above the aerator propeller when the
aerator is in operation. These shields are either flat or curved around
the aerator shaft.
These prior known devices have a number of disadvantages, all
of which are alleviated and eliminated by the present invention. The
rigidly affixed vortex shields catch material which floats in the water.
Since the shields are disposed under the surface of the water, it is
difficult, if not impossible to locate any problems with the shield.
The shields also are not able to eliminate every vortex created.
Often a vortex forms in A non-vertical direction and evades the vortex
shield. Also when a vortex escapes the shield it sometimes vibrates
the shield and tears it off. The mobile vortex shield disclosed below
solves these problems.
~UMMARY OF THE INVENTION
The present invention is directed to a mobile vortex shield which
contacts and eliminates vortices created by an aerator. The shield
floats on the surface of the aerated substance and is connected to a
support structure by flexible, elongate members which allow the shield
to float over a defined surface area of the aerated substance above
the aerator's propeller. Thus, the shield may follow a vortex until it
intercepts and eliminates it.
Propeller-type aerators can range in size, for example, from 1/2
hp to 100 hp. As the size of the aerator increases, the size of its
support system likewise increases. The present invention preferably
uses a common shield support and aerator support, so that the type of
shield support is dependent on the aerator size. The type oî support
system also depends on the type and size of the aerated substance
container (e.g., bMsin, lagoon, or tank). In the preferred embodiment
the support system for the vortex shield will comprise a slightly
modified version of the basic aerator support system. For the smaller
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aerators, addi~ional su~port members ~ay be used to cen~erthe vorkex shield over the aerator propeller. For larger
applica~ions the vortex ~h~eld attachmant ~embex~ can be
attached directly to ~he vertical and/or hor~zontal
eupport~ of the a~rator wlthout modi~Gatlon.
The shields mobility allow~ it to el~minate all
vorticeæ - not ju~ tho~ forming imme.diately above the
aerator propeller. As the shield floats on the sur~ace o~
the aera~ed substanee i~ will not catch any floating
material and trap it near th8 propellerO Nor are any
problems hidden fro~ observation. Finally, no vorti~es
will be capable of vibrating the shield and t~arinq it from
its mooring a the shield is ~lexibly attached to the
frame. Also, any vibrating will have no adverse effect on
the performance of the aerator a~ the shield is not
connected to the aerator.
Other aspects of thia invention are as follows:
A mobile vortex shield apparatus, ~or use with a
propellex t~pe aspirating aerator, for pr~venting the
formation of vortices near the aerator propeller in a
~ubstance in which the propeller i~ driven comprising-
a support system;
a floatable shield wh~ch floats on the surface of the
aarated substance;
at lea~t one flexible elongated me~ber attaching said
floatable shield to said support syst~m so a~ to enab~e
said floatable shiald to ~loat freely on the ubstance
within a dePined area o~r the propeller o~ the aerator
uch that said ~loatable ~hiQld will contact and sliminate
all vortices created by the aerator propeller by being
drawn toward~ a vortex by th~ vortex'~ own ~wirling motion.
~n aeration apparatu comprising:
a ~upport system;
a propell~r aspirator aerator ~or inducing the flo~ o~
at~o~pheric air at high velocity bQlow th~ ~urfac~ o~ a
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substance ~o as to allo~ oxygen to ~r~ely and qui~kly
tranEfer int~ the substance, said aerator bei~g attached t~
said support syctem;
a floatable ~hield which float~ on the sur~ace of the
aerated ~ub6tance;
flexibl~ elongat~d ~embers attaching sa~d floatable
hield to ~aid upport syet~m 80 as to enabl~ said
~loatable shi~ld to ~loat freely on the aerat~d sub~tance
within a d~fined ar~a over the propeller o~ the aerator
such that said floatabl~ shi~ld will contact and eli~inate
: all vortices created by the aerator propeller by being
drawn towards a vortex by the vort~x~3 oWn swirling motion.
Various advantages and ~eatures of novelty which
characterize the invention are further pointed out in the
claims that follow. How~ver, for a better und2rstanding of
the invention and it~ advantag~s r~ference 6hould be had to
the accompanying drawings and de~cr~ ptiVQ matter which
i~lustxate and describe pre~erred embodiment~ o~ the
invention.
BRIEF ~E$CRIPTION OF THE D~AWINGS
Figures 1 through 3 are per pec~ive vi~ws illustrating
various siz~d float- upport~d vor~ex shi~ld3 and asrator~
in accordan~e with ths pre~ent invention;
Figure 4 i~ a simplified view of the vortex ~hiel~ and
aerator of Figure 2;
Figure 5 i~ a ~i~plifi~d plan view og the vortex
shield and aerator o~ Figure ~:
: Figure 6 i~ a side view of a wall-~ounted vortex
~hield and aerator; and
~ igure 7 i~ a per~pective view of an additional
e~bodiment of a wall-~ounted vortex shi~ld and aerator.
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DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings in detail, wherein like numerals indi-
cate like elements, Figure 1 shows an apparatus according to the
present invention. A propeller-type aspirating aerator 10 is attached
to a support system 12. Aerator 10 comprises a motor 14 attached to
an outer housing 16. Motor 14 is drivingly coupled to tube 18 which
extends through the interior of housing 16 and out of its lower end.
A propeller 20 is attached to the lower end of tube 18. When
motor 14 rotates tube 18, propeller 20 drives the liquid surrounding it,
thereby aspirating air down tube 18 and into the liquid. Aerstor 10,
illustrated in Figure 1, is a relatively small aerator, for exarnple, a 2
to 7-1/2 horsepower aerator.
Support system 12 is a floatation type system wherein a pair of
floats 22 float on the liquid being aerated. Floats 22 function as ver-
tical supports~ i.e., providing support vertically above the surface of
the liquid. A pair of horizontAl support bars 24 are connected to
floats 22 by mounting bars 26 carried in bar rests 28 on the upper
surface OI floats 22. Support bars 24 extend horizontally between
floats 22- to function as a first horizontal support which positions
aerator 10 at a desired horizontal location (preferably centrally)
between floats 22. A.nother pair of support bars 26 extends perpendic-
ularly from bars 24 to function as a second horizontal support which
positions a vortex shield 30 at a desired horizontal location over
propeller 20. Vortex shield 30 should be of lightweight construction so
as to float on the aerated substance on which it rests. It should also
be chemically inert, biologically nondegradeable and insoluble in the
substance being aerated. A low-density polypropylene is recommended.
Vortex shield 30 is flexibly attached to support bars 26 by four
flexible attachment members 32, such as chains attached at their ends
by hooks to vortex shield 30 and support bars 26. Support bars 26
center vortex shield 30 over the propeller 20 of the aerator 10.
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Vortex shield 30 prevents the formation of a vortex ad)ncent the
propeller 20 in the substance being aerated. Since shield 30 floats on
the surface of the aerated substance, it is drawn to any vortices thst
form because the vortex pulls shield 30, along with other material in
the vicinity, towards itself. When shield 30 contacts the vortex it
eliminates it. Vortex shield 30 is free to follow vortices as it is not
rigidly attached to the aerator. Rather, it is flexibly attached to
support system 12 by a sufficient length of flexible attachment
members that permit it to float over an area large enough to
encompass all propeller-created vortices. When contacting Q vortex,
shield 30 will not vibrate and/or damage ~erator 10 because it is not
rigidly affixed to aerator 10.
The remaining Figures illustrate vortex shields used with differ-
ent types of support systems and/or different sized aerators. Common
elements of the support system and aerators will identify with the
same numerals and the vortex shield will be identified by a like
numeral and a letter suffix.
Figures 2 and 4 show a medium sized aerator 10, e.g. lû to 30
horsepower, carried on a floatation type support system 12. As shown
in Figure 4, three floats 22 are used. Because of the placement of
aerator 10 relative to support system 12, it is not necessary to use
the second horizontal support of support bars 26 to position vortex
shield 30A over propeller 20. Shield 30 is supported by the flexible
attachment members 32, two of which are fastened to one of the
horizontfll support bars 24 and two of which flre fastened directly to
one of the mounting bar rests 28 on floats 22 which comprise vertical
supports for support system 12. The function and characteristics of
vortex shield 30A remsins the same.
Figures 3 and 5 illustrate a large sized aerator 10, e.g., 40 to
100 horsepower carried on a floatation-type support system 12. In this
embodiment the verticsl supports comprise floflts in order to
sccommodate the lar~e aerator. As seen in Figure 5, five floats are
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used to carry the large sized aerator 10. In this embodiment, nexible
attachment members 32 which support vortex shield 30B, are all
connected directly to mounting bar rests 28 on noats 22.
Figure & illustrates a medium sized aerator 10 carried on a wall
mount support system 40 instead of a floatation system. In this con-
figuration the vertical support comprises a vertically extending
framework 42 mounted on a wall 44 of the aeration tank. The hori
zontal support includes a pair of horizontally extending support bars 46
(one of which is shown in Figure 6) oriented parallel to the axis of
the aerator instead of perpendicular to it. Vortex shield 30C and
aerator 10 are both carried by support bars 46.
Figure 7 shows small sized aerator 10 supported on A wall
mount 50. Vortex shield 30D is attached by flexible attachment
members 32 to a pair of horizontal support bars 52 extending from the
vertical wall. The horizontal support bars 52 are separate from wall
mount S0 supporting aerator 10.
Numerous characteristics and advantages of the invention have
been set ~orth in the foregoing description together with det~ils of the
structure and function of the invention, and the novel features thereof
are pointed out in the appended claims. The disclosure, however, is
illustrative only, and changes may be made in detail especially in
matters of shape, size and arrangement of parts, within the principle
of the invention, to the full extent extended by the broad general
meaning of the terms in which the appended claims are expressed.
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