ilnite 1 Ravitts States Patent [191 1 LIQUID SPRAY DEVICE WITH FIXED AND ROTATABLE DIFFUSERS Richard B. Ravitts, Rockford, Ill.
73 Assignee: Richards of Rockford, Inc.,
 Filed: May 27, 1971  Appl. No.: 147,472
120 deflected outwardly of the throat by an annular baffle encircling the upper end of the neck. The baffle ex-  References Cited tends outwardly from the neck in a generally horizontal direction to guide the deflected water in a relative- UNITED STATES PATENTS ly flat trajectory to cause the water to strike the sur- 2 137 397 11/1938 Haldeman ..261/36 R face the Pond with nsiderable fOrce- A mtatable 3:572: 5 3 1971 Raving 2 1 3 R diffuser positioned above the fixed diffuser coacts 3,669,422 6/1972 Nogaj 261/34 R therewith to sling the central core of water outwardly 3,416,729 12/1968 Ravitts et a1... ..239/16 relative to the throat in a path above and converging 1.674.489 1923 Nelson 1 9/500 X downwardly into the water deflected by the baffle. 1,082,815 12/1913 Melas.... .....239/500 X 1,542,136 6/1925 Hodge ..239/500 X 8 Claims, 5 Drawing Figures l/1937 Webre ..239/500 2,068,094 1,996,098 4/1935 Chase ...239/500 X 2,342,596 2/1944 North ..239/224 X Rrin q y Examiner-Robert 8. Ward, Jr.
Attorny- Hume, Clement, Brinks et al.
 ABSTRACT A floating aerator includes an axial flow impeller rotated by an electric motor and disposed within a tubular throat to pump a column of water from a pond upwardly through the throat and against a stationary or fixed diffuser positioned above the upper outlet of the throat. The fixed diffuser divides the column of water into a central core which passes through a neck portion of the diffuser and an outer sleeve which is Patented May 29, 1973 3,735,926
2 Sheets-Sheet 1 Patented May 29, 1973 2 Sheets-Sheet 2 may f) III/6? LIQUID SPRAY DEVICE WITH FIXED AND ROTATABLE DIFFUSERS BACKGROUND OF THE INVENTION This invention relates to a liquid aerator of the type typically used in ponds or tanks to enrich the oxygen content of water or other liquid, to scrubundersirable gases from the water, to produce an induced flow in the pond for mixing and solid suspension purposes, or to cool large quantities of water for recirculation. More particularly, the invention constitutes an improvement over an aerator such as disclosed in Ravitts U.S. Pat. No. 3,4l6,729 in which the water is pumped upwardly from a pond through an upright tubular throat by a motor driven impeller and impinges against a power rotated diffuser which slings the liquid outwardly relative to the throat for interface contact with the surrounding air prior to falling back into the pond.
SUMMARY OF THE INVENTION The general object of the present invention is to provide an aerator of the above general character which is capable of aerating a greater volume of liquid with a motor of a given horsepower than prior aerators of the same general type. More particularly, the invention aims to deflect substantially all of a column of liquid pumped upwardly through the throat without need of the entire column being deflected by the rotatable diffuser and causing an excessive expenditure of horsepower.
A more detailed object is to achieve the foregoing by positioning a unique stationary diffuser in the path of the rising column of liquid to divide the column of liquid into a central core and an outer sleeve, the latter being deflected outwardly of the throat by the stationary diffuser while the central core continues upwardly to impinge against the rotatable diffuser and to be slung outwardly thereby such that substantially all of the rising liquid is deflected by the combined action of the stationary and rotatable'diffusers.
The invention also resides in the novel construction of the stationary diffuser and in its unique coaction with the rotatable diffuser to deflect all of the water, to prevent freezing of the water on the fixed diffuser during cold weather and to effect a smoother flow of liquid across the impeller.
Other objects and advantages will become apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of an aerator embodying the novel features of the present invention.
FIG. 2 is a fragmentary side elevational view of the aerator, parts being broken away and shown in section.
FIG. 3 is a fragmentary cross-sectional view taken substantially along line 3-3 of FIG. 2.
FIG. 4 is a perspective view of a part of the aerator.
FIG. 5 is an enlarged fragmentary elevational view of parts of the aerator with parts broken away and shown in section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings for purposes of illustrating, the invention is embodied in a liquid aerator (FIG.
oxidize the water therein by continuously drawing water upwardly out of the pond and then slinging the water into the surrounding atmosphere for interface contact with the air before falling back to the surface of the pond. The water is slung outwardly from the aerator with considerable turbulence so that noxious gases in the water are released and are replaced by oxygen from the atmosphere. At the same time, a flow of water is induced in the parent body to mix the water therein.
More specifically, the floating aerator is carried by a support comprising a buoyant float 11 formed by a stainless steel outer shell 13 which is filled with a low density material 14 such as polyurethane foam. The float may be moored in the pond by attaching cables (not shown) to eyes 15 angularly spaced around the periphery of the' shell.
Extending vertically through the center of the float 11 is a cylindrical opening 12 into which is telescoped an upright tubular throat 16 defining a passage accommodating the flow of water upwardly out of the pond and into the atmosphere. At its inlet end, the throat is formed with an outwardly flaring intake shroud 17 immersed in the water and establishing an entryway into the throat. The upper outlet of the throat is of predetermined diameter and is located just above the top of the float to discharge the water into the atmosphere.
Water is pumped upwardly from the pond and through the throat 16 for interaction with the air by an axial flow impeller 19 telescoped into the throat and fastened to the lower end of a rotatable impeller shaft 20 extending axially into the throat and driven by an electric motor 21. The latter is mounted on a platform 23 which is supported above the upper surface of the float 11 by a plurality of upstanding legs 24 angularly spaced from each other and establishing wide flow passages between the float and the platform for the outward discharge of the water.
As the water emerges from the upper end of the throat 16, it impinges against a rotatable diffuser 25 (FIG. I), is slung upwardly and outwardly above the upper side of the float l1 and is dispelled over a wide area. The diffuser is fastened to and rotatable with the impeller shaft 20 just below the platform 23 and preferably is formed on its outer side with an upwardly and outwardly curving concave surface 26 against which the upwardly rising water impinges. The water slung outwardly by the diffuser is churned and mixed with the air with a vigorous scrubbing action thereby producing a high rate of oxygen transfer from the air to the water.
In accordance with the present invention, provision is made of a stationary diffuser 27 which coacts with the rotatable diffuser 25 in a novel manner to enable the aerator 10 to pump and aerate a greater volume of liquid with the motor 21 of given horsepower. For this purpose, the stationary diffuser is positioned above the outlet of the throat 16 and below the rotatable diffuser to continuously divide a column 29 (FIG. 2) of upwardly rising liquid into a central core 30 and an outer sleeve 31 (FIG. 5), the latter being sheared from the column and deflected outwardly of the throat by the stationary diffuser. The central core flows upwardly through the stationary diffuser, impinges against the rotatable diffuser, and is slung outwardly across the float 11 and between the two diffusers in a path above and converging downwardly upon that of the liquid deflected by the stationary diffuser. This arrangement deflects and diffuses all of the liquid rising upwardly through the throat and yet permits the use of a rotatable diffuser of smaller diameter then has been possible heretofore with a throat of a given size so as to reduce the amount of energy absorbed by the rotatable diffuser in slinging the water outwardly with the result that more power is used to pump the liquid through the throat thereby increasing the volume of liquid that can be aerated without increasing the size of the motor 21.
Herein, the stationary or fixed diffuser 27 is positioned coaxially with the shaft and includes a tubular neck 33 whose lower end is located just above and is concentric with the outlet of the throat 16. The neck is flared at its upper end, curving gradually to merge with an annular baffle 34 which extends outwardly thereof in a generally horizontal direction past the edge of the throat outlet as shown in FIGS. 2 and 5. A plurality of angularly spaced notches 35 (FIGS. 3 and 4) are cut in the periphery of the baffle to permit the fixed diffuser to fit over the legs 24. Brackets 36 are fastened to the baffle adjacent the notches by screws 37 and are welded to the legs 24 which thus hold the stationary diffuser in a fixed position just above the throat outlet. Thus, the fixed diffuser is mounted on the aerator in a position concentric with the shaft and adjacent the throat outlet.
As shown in FIG. 2, the neck is smaller in diameter than the throat outlet so as to divide the upwardly rising column of water into the central core 30 which flows upwardly through the neck 33 and the outer sleeve 31 which flows upwardly along the outer wall 39 of the neck and the bottom side 40 of the baffle 34. The gradual curvature of the merging surfaces of the neck and baffle gives the outer surface of the stationary diffuser 27 a relatively streamlined concave shape so as to deflect the sleeve of water outwardly relative to the throat 16 and over the top of the float 11 in a substantially flat trajectory (see FIG. 2). This deflected water strikes the surface of the pond with considerable velocity and imparts an outwardly directed thrust to the water in the pond so as to induce a circulatory flow upwardly around and outwardly from the float as shown in FIG. 2. This results in a higher velocity outwardly induced flow to produce mixing and solid suspension over a greater area per applied horsepower than is the case when the diffused water falls into the pond at a steep trajectory.
The rotatable and fixed diffusers 25 and 27 coact with each other to deflect the central core 30 outwardly relative to the throat 16 in a path above and converging downwardly on that of the liquid deflected from the sleeve 31. For this purpose, the outer concave surface 26 (FIG. 5) of the rotatable diffuser is positioned inwardly of the inner wall 41 of the neck 33 and above the top surface 43 of the baffle 34 with the lower portion of the rotatable diffuser telescoped into the upper end of the neck as shown in FIG. 2. Thus, with the inner wall 41 of the neck defining a flow passage for the central core, the latter is guided to impinge against the rotatable diffuser 25 and be slung outwardly thereby between the two diffusers. The inner wall 41 of the neck is convex and conforms generally to the shape of the outer surface 26 of the rotatable diffuser so that a streamlined, outwardly flaring passageway is defined between the two diffusers for guiding the deflected flow over the upper side 43 of the baffle. This flow of water between the two diffusers keeps the upper surface 43 of the baffle continuously wetted and prevents the formation ofice on the upper surface during cold weather.
The space or size of the orifice between the fixed and rotatable diffusers 25 and 27 may be varied to change the flow path of the water therebetween. For this purpose, the rotatable diffuser is connected to the shaft 20 by a coupling 44 (FIG. 5) connected to the lower portion of the rotatable diffuser. The coupling is mounted on the shaft and includes a ring 45 and a collar 46, the latter being mounted within the rotatable diffuser at its lower end. The hole in the collar flares outwardly at its lower end to receive an upwardly tapered flange 47 extending upwardly from the top of the ring. The flange wedges between the outer edge of the hole and the shaft and is clamped tightly against the shaft as a screw 49 is turned to fasten the ring, the collar and the diffuser to one another. Loosening of the screw allows the rotatable diffuser to slide and to be positioned selectively on the shaft relative to the fixed diffuser so as to obtain the best deflection of the central core 30. Moreover, by properly establishing the size of the orifice between the two diffusers and also by positioning the fixed diffuser to establish an orifice of given size between the fixed diffuser and the throat 12, more nearly laminar flow can be produced across the impeller 19 to reduce turbulence and increase the pumping capacity. That is, differential back pressures can be created across the length of each of the impeller blades so that the slower velocity inner portion of each blade pumps against a lower back pressure than the higher velocity outer portion of the blade thereby to reduce downward cascading of the water onto the inner portions and, in effect, to provide boundary layer control.
Thus, it will be readily seen that the deflection of the sleeve 31 of water by the fixed diffuser 27 permits the use of a rotatable diffuser 25 which is substantially smaller in diameter than otherwise would be the case if the rotatable diffuser were required to deflect all of the water flowing upwardly through the throat 16. Consequently, less energy is absorbed by the rotatable diffuser in slinging water outwardly of the throat so as to allow more power to be used in the pumping of the water upwardly through the throat with the result that more water may be aerated without increasing power.
I claim as my invention:
1. A liquid aerator comprising: conduit means adapted for immersion in a body of liquid at its lower end and defining an opening at its upper end for the discharge of liquid pumped upwardly therethrough, power driven impeller means rotatable within said conduit means to pump a column of liquid upwardly through the conduit means for discharge from the upper open end thereof, stationary diffuser means fixedly mounted above an outer radial portion of said impeller and adjacent the outer upper end of said conduit for dividing and deflecting an outer portion of the rising column of liquid outwardly, and rotatable diffuser means positioned above the inner radial portion of said impeller for deflecting an inner portion of the rising column of liquid and for slinging such inner liquid portion outwardly.
2. The liquid aerator of claim 1 in which said conduit means is tubular, said stationary diffuser means divides the rising column of liquid into a central core and an outer sleeve, and said stationary diffuser means is posi tending above said stationary diffuser means.
4. An aerator as defined in claim 1 in which said rotatable diffuser comprises a generally concave outer surface curving upwardly for outwardly directing the liquid impinging against its surface.
5. An aerator as defined in claim 1 in which said stationary diffuser means comprises inner wall portion and outer baffle portion, said inner wall portion defining a surface spaced from the outer surface of said rotatable diffuser means.
6. An aerator as defined in claim 1 in which said stationary diffuser means comprises a baffle portion having a substantially horizontal side for imparting a substantially flat trajectory to the liquid.
7. An aerator as defined in claim 1 in which the distance between said stationary and rotatable diffuser means is adjustable relative to the other for adjustment of the relative sizes of the two portions of liquid.
8. An aerator as defined in claim 1 in which said rotatable diffuser means is vertically adjustable at various .selected elevations relative to said stationary diffuser means.
UNITED STATES PATENT orFicE CETIFICATE @l CEC'HWN Patent o. 3,735,926 Dated May 29, 1975 Inventor(s) Richard Ravitts It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
IN THE ABSTRACT Line 1, before "aerator" insert spray device, for example, an
IN THE SPECIFICATION Column 1, line 5, before "aerator" insert spray device, for example, an
' Column 1, line 22, after "provide" insert a liquid spray device, for example,
. Column 1, lines 52-55, 56, 59, 61,67, cancel "aerator" and substitute spray device Column 2, lines 9, 15-16, 63, cancel "aerator" and substitute spray device Column 3, line 33, cancel "aerator" andsubstitute spray device IN THE CLAIMS Column 4, line 55 after "liquid" insert -spray device, adapted for use as an Column 5, line 4, cancel "aerator" and substitute spray device FORM Po-ioso (10-69) USCOMM-DC 60376-P69 u. 5. GOVERNMENT PRINTING oFrlc: I989 0-366-334.
UNITED STATES PATENT @FFIEE Page 2 CERTIFICATE OF C EQTEON Patent No. ,735,926 Dated May 29, 1973 Inventor) Rl chard B. Ravltts It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 5, lines 11 and 16, cancel "An aerator" and substitute The spray device Column 6, lines 1, 6, l0, and 14, cancel "An aerator" and substitute The spray device Signedandsealed this 26th day of February 1975;.
EDWARD M.FLE'I CHER,JR. C. MARSHALL DANN Att ing ffi Commissioner of Patents FORM PO-IOSO (10-69) USCOMM-DC 60376-P61 r: u. s. GOVERNMENT PRINTING OFFICE I969 0-565-33