US3685810A

US3685810A - Splash surface aerator

Info

Publication number: US3685810A
Authority: US
Inventors: Hartwell Forrest Calcote
Original assignee: AEROCHEM RES LAB
Current assignee: AEROCHEM RES LAB; AEROCHEM RESEARCH LAB Inc
Priority date: 1970-08-17
Filing date: 1970-08-17
Publication date: 1972-08-22
Anticipated expiration: 1989-08-22

Abstract

Apparatus and process for aerating a liquid by subjecting the surface of the liquid to the impingement of a body to cause the liquid in the area of impingement to splatter. Splattering substantially increases the gas-liquid interface of the liquid and facilitates absorption of gas in the liquid while requiring low power requirements. Apparatus and process of this invention are particularly useful for aerating water or sewage wastes to replenish oxygen or supply additional oxygen to aid in the breakdown of waste materials in aerobic systems.

Description

Umted States Patent 1151 -3,685,8 1 0 Calcote 1 1 Aug. 22, 1972 SPLASH SURFACE AERATOR 1,275,583 1 8/1918 Mathys ..26l/81 72 I t Hart F "est Calcot P t 1,132,982 3/l915 Serrell l3 1 or 1,305,860 6/1919 Y ount ..2s9/113 2,498,393 2/ 1950 Clewell ..25,9/ 1 1'3 1 Asslgnee= AeroChem Research Laboratones, 1,653,321 12/1927 Swett .259/1 13 km 3,462,132 8/1969 Kaelin ..26l/93 [22] Filed: Aug. 17, 1970 Primary Examiner-Tim R. Mlles [21] APPL 64,237 Assistant Examiner-Stven H. Markowitz Attorney-Theodore B. Roessel [52] US. Cl. "261/81, 261/119, 259/113 I 51 1m. (:1. .1101: 3/04 1571 AB TRACT a Fleld of Search ..6l/l, 70, 1 12, App atu nd process aerating a ubject- 259/113 261ml 1 93 ing the surface of the liquid to. the impingement of a body to cause the liquid in the area of impingement to [56] Reierences cued splatter. Splattering substantially increases the gas- UNITED STATES PATENTS liquid i terface 0f the liquid facilitates absorption of gas 1n the l1qu1d whlle requlrmg low power requlre- Dlcketman et a1. ments Apparatus and process of invention are GOSS useful for aerating water or ewage wastes 1,632,943 6/ 1927 Beebe ..259/1 12 to replenish oxygen or Supply additional oxygen to aid 1 19,898 10/ l87l NlChOlS et a] ..259/ 1 12 in the breakdown of waste materials i aerobic 107 ,443 9/ 1870 Bullock ..25 9/ l 12 systems 1,452,097 4/1923 Ross ..259/1 12 425,645 4/1890 White ..259/1 13 8 Claims, 9 Drawing figures PATENT EI M1322 I97? 3 6 85 8 l O sum 1 or 2 INVENTORS HARTWELL F. CALCOTE ATTORNEY sum 2 BF 2 ll llll INVENTORS' HARTWELL F CALCOTE ATTORNEY SPLASH SURFACE AERATOR This invention relates to apparatus for introducing a gas or a mixture of gases into a liquid.

BACKGROUND OF THE INVENTION A major technique used in the treatment of water, sewage waste and the like, is the introduction of oxygen into the water or sewage waste to replenish oxygen or to supply additional oxygen to aid the breakdown of waste materials in aerobic systems. The atmosphere generally provides the oxygen source and the technique for introducing atmospheric oxygen into the water involves, with very few exceptions, the rotation of an impeller type device which causes the fluid to move at a great volocity. The main objective is to maximize the water-gas interface through which oxygen can be transported from the atmosphere to the liquid. Such techniques involve the use of large amounts of power for the pounds of oxygen per horsepower hour absorbed in the liquid. Generally speaking, such high consumptions of power are due to the fact that large volumes of water must be moved at relatively high velocities in order to achieve the necessary gas-water interface. Moreover, such systems often require supplemental sources of oxygen in addition to oxygen present in the atmosphere.

Accordingly, it is an object of this invention to provide apparatus to improved gas introducing capacity per horsepower hour in order to increase the efficiency and the economy of the operation.

Another object of this invention is to provide apparatus for introducing gas into liquid wherein there is provided at least one splasher head for striking the liquid surface substantially perpendicularly thereto, thereby to form on and about the liquid surface, watergas interfaces through which the gas is introduced into the liquid.

These and other objects and advantages of this invention will become apparent upon consideration of the following detailed description and the drawings and the novel features thereof will be particularly pointed out hereinafter in connection with the appended claims.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a side elevation of an embodiment of apparatus represented schematically.

FIGS. 2A-2D illustrate various configurations of splasher heads in accordance with this invention.

FIG. 3 shows a portion of the apparatus of FIG. 1 illustrating means for limiting downward movement of the splasher head.

FIG. 4 illustrates schematically another embodiment of this invention employing an arm driven in a see-saw manner.

FIG. 5 illustrates yet another embodiment of this invention employing a crankshaft.

FIG. 6 illustrates an embodiment of this invention employing a reciprocating solenoid or linear induction motor.

SUMMARY OF INVENTION I have discovered that unexpectedly high rates of gas absorption in liquids are obtained when a body is impinged against a liquid surface with suflicient energy to displace and spatter the surface liquid and thereby substantially increase the water-gas interface of the spattered liquid for the absorption of surrounding gases in the spattered liquid. Repeated impingement on the liquid surface by said body results in efficient gas absorption in the liquid.

The size and shape of the splasher will vary, depending upon the type of drive mechanism, the number of impacts per minute and the amount of force imparted to the splasher at the liquid surface. The drive means for effecting the raising and lowering of the splasher head may be of any conventional type. Best results are obtained when the splasher head, impinges the liquid surface substantially perpendicularly thereto. Any substantial penetration of the splasher head under the liquid surface should be avoided since raising the splasher head from under the surface requires undue amounts of energy and substantially reduces the efficiency of the process of the invention.

DESCRIPTION OF THE INVENTION Referring now to FIG. 1, there is shown in schematic form, an embodiment of this invention illustrating the basic principles thereof wherein a body of water 11, is aerated by the substantially perpendicular impingement of splasher head 12 on the surface thereof. Splasher head 12 is carried by line 13 by way of pulley 14 supported over said water surface by suitable means, not shown, to winch 16. Winch 16 is driven by suitable means such as for example, electric motor 17. Suitable clutch means are provided for winch 16 to disconnect winch 16 from motor 16 and to provide for the free-fall of splasher head 12 from its raised position as shown at 12a.

In operation, pulley 14, was positioned over the approximate center of a test basin having nominal dimensions of 15 feet in diameter by 4 feet in depth and containing 5,800 gallons of water. The pulley 14, was approximately 10 feet above the water surface. Line 13 was run from winch 16 through pulley 14 to splasher head 12. Splasher head 12 was raised aknown distance by rotating winch 16 by means of motor 17 to a position shown as broken lines at 12a. Release of the clutch means allowed splasher head 12 to free-fall thereby to impinge on the water surface substantially perpendicularly thereto. The length of line 13 was selected so as to allow impingement of splasher head 12 on the water surface in its downward position but prevented substantial penetration of splasher head 12 under the water surface. After impact, splasher head 12 was returned to its starting position 12a. For testing purposes this cycle was repeated six times per minute for a total of 10 minutes.

To determine the rate of oxygen uptake in the water, dissolved oxygen content was measured with a Yellow Springs Dissolved Oxygen Meter. Two dissolved oxygen measurement probes were located 8 inches below the surface of the water and at a radial distance of 5 feet and 5.5 feet from the center of the test basin. Prior to beginning each test, the water was de'oxygenated to about 1 part per million by the addition of sodium sulfite and colbaltous chloride.

Referring to FIG. 2A, the splasher head was in the shape of an inverted cone, the side surfaces of which had a slight concavity. The splasher head was weighted with sand to a total weight of 25 pounds. For the purposes of this test, the splasher head had an axial dimension of 9 inches and a maximum diameter of 19 inches.

A small mixer was operated during the tests to substantially uniformly distribute dissolved oxygen throughout the test basin.

The rate of dissolved oxygen uptake (D.O. lb/hr.) was computed as follows:

where y equals'oxygen uptake (ppm) fora given run and t equals time in hours.

Horsepower was determined according to the formula:

where w equals the weightofthe splasher, 1b., h equals the height above surface, ft., n equals total number of cycles and t equals time in hours.

9.6-10 -y Then, oxygen uptake efficlency 1n lb./Hp.-hr.= W

The results of the tests are set forth in Table I.

TABLE I Measured Oxygen Uptake Efficiency No. 7 Oxygen Splasher cycles Impact Initial Final Oxygen Uptake 4 height (6 cycles velocity D0. D0. uptake eft'lc /min) t/ (pm) (pm) (pm) iency (lb/hP -hr 2 60 12 1.5 2.0 0.5 16 3 60 14 1.2 1.7 0.5 11 3 60 16 1.5 2.0 0.5 11 4 60 .16 1.7 2.4 0.7 11

The economy of the apparatus of this invention can be further increased by storing that portion of the kinetic energy of the splasher which is in excess of the energy required to disperse and splatter the water at the impact area. Furthermore, it is undesirable to have the splasher head penetrate the water surface to any substantial depth since there is little or no gas exchange brought about when the splasher head is submerged beneath the water surface and the energy requirements to raise the totally immersed splasher head substantially reduce the efficiency of the operation Referring to FIG. 3, there is shown one'method for limiting the downward travel of the splasher head and for utilizing.

excess kinetic energy to aid in returning the splasher head to its raised position. Thereis shown a fragment of the apparatus shown in FIG. 1 wherein splasher head 23 is attached to line 21 running from a powered In second series of tests, the splasher head shape was changed slightlyas shown in FIG. 2B and although the general configuration of the splasher head remained as an inverted cone, the side surfaces thereof were substantially straight line and the weight of the splasher was increased to 31.5 lbs. As in the previous tests, all cycles were at the ratejof 6 per minute. The results are set forth in Table II belowz' The average oxygen uptake efiiciency obtained in both tests was about 12 lb/hp-hr.

Referring to FIG. 2C, there is shown another design for a splasher head wherein the head comprises a generally hejrnispheroidal shape. FIG. 2D shows yet another embodiment of a splasher head wherein plate 18 is provided with a multiplicity of perforations 19. It should be clear that the size and weight of the splasher head will be dependent upon the drive mechanism, the number of cycles and the impact velocity.

winch, not shown, through pulley 22 for the raising of splasher head 23 above the surface of the water 20 and for allowing the free fall thereof to the water surface. Splasher'head 23 is provided with an axial passage 26 through which runs anchor cable 24. Anchor cable 24 may be carried by the pulley support means, and suitably anchored on the shore. When anchor cable 24 is carried by the pulley support means, said support means is suitably reinforced to absorb the shock of splasher head 23. Passage 26 is sufliciently large to allow for the free travel of splasher head '23 along anchor cable 24. Depending from anchor cable is plate 27 located beneath the surface of the water. Plate 27 is of sufficient weight so as to maintain said anchor cable 24 in a substantially vertical position. Spring 28 is carried by plate 27 and is positioned thereon coaxially with anchor cable 24. Spring 28, in its fully extended position, and plate '27, are located beneath the water to allow for the impingement of the water surface by splasher head 23 while'at the same time making contact with'splasher head 23 to prevent complete penetration of the water surface by splasher head 23.

In operation, splasher head 23 is raised by means of line 21 above the surface ofwater 20. Splaslier head 23 is then allowed to free-fall to impinge upon the water surface to effect the aeration thereof. After initially impinging on the surface splasher head 23 contacts the upper end of spring 28 causing it to store the excess kinetic energy of splasher'head 23 as it is compressed by the downward travel of splasher head 23. At the completion of the downward travel, splasher head 23 is then withdrawn from the water and returned to a raised position, which initial withdrawal is assisted by the upward urging eflect of spring 28.

It should be clear that many treatment basins are substantially shallow and that, therefore, plate 27 can be readily carried by support means resting on the bottom of the basin rather than by an anchor cable of the type shown.

splasher head to spatter the water at'and'around the surface thereof thereby to the water-gas interface for the absorption of gas. In addition, more than one splasher head ma be employed in the apparatus of this invention.

Referring to FIG. 4, the apparatus is supported on the bottom of the lagoon by uprights 31 carrying platform 32. Pivoted on platform 32 is rocking arm 33 which carries at either end,

splasher head

34 and 34. Rocking arm 33 is driven by conventional means such as rotary air motor 35 to provide a see-saw motion to said arm 33 so that said splasher heads 34 and 34' alternately impinge upon the surface of the water. The length of each half of arm 33 is such that splasher head 34 and 34' impinge upon the water surface during the downward travel of the respective ends of arm 33 but do not substantially penetrate the water surface. Sufiicient driving force is provided to raise one end and splasher head of said arm while imparting energy to the downward moving half of said arm to effect splashing and resultant gas absorption. If desired, suitable means may be provided, such as for example the type illustrated in FIG. 3, for limiting the downward travel of heads 34 and 34' and for urging

heads

34 and 34 away from the water surface after impingement thereof by

heads

34 and 34.

Referring to FIG. 5, there is shown partially in section, another embodiment of this invention wherein the apparatus is floating on a basin surface.

Floats

41 and 41 are connected at their ends by frame member 42. Motor 43 is carried by float 41 for driving crankshaft 44 which is journaled at its opposite end by journal bearing 45 carried by float 41'. Suitable transmission and fly-wheel means 46 are also provided. Connecting rods 48 are carried by said crankshaft 44 by means of bearings 49 and splasher heads 47 are connected to each of said connecting rods 48.

Although not shown, floats 41 and 41 may be provided with ballast means for adjusting the depth of penetration of splasher head 47 into the water surface.

Referring to FIG. 6, there is shown a sectional schematic side elevation of another embodiment of this invention therein splasher head 51 is driven by a reciprocating solenoid motor. The solenoids consists of windings 52 and 52' coaxially wound about shaft cylinder 53. Guide shaft 54 having ferro-magnetic core 56 embedded therein, carries splasher head 51. The upper end of shaft 54 terminates with plate 57. Shaft cylinder 53 is of sufficient diameter to allow for the reciprocal travel of guide shaft 54 therethrough. In the embodiment shown, spring 58 is coaxially positioned in the upper end of shaft cylinder 53 in surrounding relationship to shaft 54. Spring 58 is carried in shaft cylinder 53 by annular lip 59. Solenoid windings 52 are connected to a source of current through a conventional current reversal switch 61.

In operation the apparatus is positioned above the water and switch 61 is set for causing current to flow through solenoid windings 52 causing iron core 56 to be urged upwardly causing guide shaft 54 and splasher head 51 to travel upwardly. When splasher head 51 has been raised to a desired height above the water, switch 61 is activated to cause current flow through the windings of the solenoid 52 and cause core 56, shaft 54 and splasher head 51 to move in a downward direction. On completion of the downward stroke, plate 57 contacts spring 58 causing it to begin to compress and to limit the downward travel of shaft 54 and splasher head 51. Switch 61 is again activated to switch the current to solenoid windings 52 thereby causing the upward movement of splasher head 51 away from the water in the manner described above. In addition,

' spring 58 acting against plate 57- aids in reversing the The force-stroke characteristics of the solenoid motor are determined by the spacing, number and diameter of solenoid windings 52 and 52'. The forcestroke characteristics may be altered by varying said spacing, number and diameter of said solenoid windings 52 and 52'.

While various driving means have been described, it should be clear that reciprocal type driving means, such as for example-reciprocal air motors and drive mechanisms of the type used in drilling apparatus, pile drivers and the like, may be used with equal success, it being important only that the driving means selected allow for the impingement on the water surface of a body with sufiicient force to cause splattering of the water surface in area of impingement thereby to maximize the gas-liquid interface to facilitate the inclusion of gas in a liquid.

From the foregoing description, it is readily apparent how the present invention accomplishes its various objectives. While the invention has been described and illustrated herewith, with reference to certain preferred embodiments thereof, it is to be understood that it may be otherwise embodied within the scope of the appended claims.

I claim:

1. An aeration system comprising means confining a large body of liquid'to be aerated, mechanical means supporting at least one splasher head having an impinging surface above the surface of said liquid body, drive means for imparting reciprocal motion to said splasher head in impinging relationship to said surface, and limiting means for limiting penetration of said liquid surface by said splasher head and confining said head to the vicinity of the liquid surface.

2. Apparatus of claim 1 wherein said limiting means is adapted for imparting reciprocal motion to said. splasher head after impingement of a liquid surface thereby.

3. Apparatus of claim 1 wherein said splasher head is carried by a line running througha pulley supported above said liquid surfaceto a driven winch, said winch being provided with clutch means whereby said splasher head may be raised above said liquid surface Y and released to impinge thereon thereby to effect aeration of said liquid.

4. Apparatus of claim 3 wherein spring means are provided for contacting said splasher head after impingement by said splasher head of said water. surface thereby to limit complete penetration of said surface by said splasher head and to urge said splasher head inareciprocal direction.

5. Apparatus of claim 1 wherein a splasher head is carried at each end of a beam supported substantially at its center so that each of said splasher heads carried by each end is in impinging relationship to said liquid surface and driving means is provided for driving said beam in a see-saw motion whereby reciprocal motion is imparted to each of said splasher heads for impingement thereof on said liquid surface.

6. Apparatus of claim l'wherein said splasher head is carried in impinging relationship to said liquid surface a by a crankshaft whereby rotation of said crankshaft imparts reciprocal motion to said splasher head.

7. The apparatus ,of claim 6 wherein a plurality of splasher heads are carried by said crankshaft.

8. Theapparatus of claim 1 wherein saidudriving means comprises a source of current, at least two solenoids, a shaft, carrying said splasher head, reciprocally, coaxially positioned in impinging relationship to said liquid surface within said solenoids, said shaft containsaid solenoids imparts reciprocal motion to said sh carrying said splasher head.

Claims

1. An aeration system comprising means confining a large body of liquid to be aerated, mechanical means supporting at least one splasher head having an impinging surface above the surface of said liquid body, drive means for imparting reciprocal motion to said splasher head in impinging relationship to said surface, and limiting means for limiting penetration of said liquid surface by said splasher head and confining said head to the vicinity of the liquid surface.

2. Apparatus of claim 1 wherein said limiting means is adapted for imparting reciprocal motion to said splasher head after impingement of a liquid surface thereby.

3. Apparatus of claim 1 wherein said splasher head is carried by a line running through a pulley supported above said liquid surface to a driven winch, said winch being provided with clutch means whereby said splasher head may be raised above said liquid surface and released to impinge thereon thereby to effect aeration of said liquid.

4. Apparatus of claim 3 wherein spring means are provided for contacting said splasher head after impingement by said splasher head of said water surface thereby to limit complete penetration of said surface by said splasher head and to urge said splasher head in a reciprocal direction.

6. Apparatus of claim 1 wherein said splasher head is carried in impinging relationship to said liquid surface by a crankshaft whereby rotation of said crankshaft imparts reciprocal motion to said splasher head.

7. The apparatus of claim 6 wherein a plurality of splasher heads are carried by said crankshaft.

8. The apparatus of claim 1 wherein said driving means comprises a source of current, at least two solenoids, a shaft, carrying said splasher head, reciprocally, coaxially positioned in impinging relationship to said liquid surface within said solenoids, said shaft containing a core responsive to the polarity of a magnetic field created by the flow of current through said solenoids and means for switching current flow between said solenoids whereby alternating current flow between said solenoids imparts reciprocal motion to said shaft carrying said splasher head.