US3612396A

US3612396A - Turbulent flow liquid discharge nozzles

Info

Publication number: US3612396A
Application number: US32332A
Authority: US
Inventors: John O Hruby Jr
Original assignee: Rain Jet Corp
Current assignee: Rain Jet Corp
Priority date: 1970-04-27
Filing date: 1970-04-27
Publication date: 1971-10-12
Anticipated expiration: 1988-10-12

Abstract

A family of aerating liquid discharge nozzles, each of which has the feature that it contains no moving parts and includes a hollow body defining a liquid inlet at one end and an outlet opening at the other end. The body has an internal chamber arranged in communication with both the inlet and outlet ends of the body. Plug means, having substantial length between its opposite end surfaces, is disposed across the chamber adjacent the body outlet end and defines a plurality of grooves which comprise constricted liquid outlet means from the body. The body outlet opening has an area greater than the area of the liquid outlet means. The grooves intermediate their length are increased in cross-sectional area in a discontinuous manner relative to the adjacent portions of the grooves.

Description

United States Patent [72] Inventor John O. ll-lruby, Jr.

Burbank, Calif. [21] Appl. No. 32,332

22 Filed Apr. 21, 1970 [45] Patented Oct. 12, 1971 [73] Assignee Rain Jet Corp.

Burbank, Calif.

Continuation-impart of application Ser. No. 784,541, Dec. 9, 1968, now Patent No. 3,558,053, Continuation-impart of application Ser. No. 691,111, Dec. 8, 1967, now abandoned Continuation-impart of application Ser. No. 492,389, Oct. 4, 1965, now abandoned.

s4 TURBULENT now mourn DISCHARGE NOZZLES 21 Claims, 6 Drawing Figs.

[52] US. Cl 239/17, 239/428.5,239/552 [51] Int. Cl B05b 17/08 [50] Field of Search 239/16, l7,

19, 22, 428.5, DIG. 1, DIG. 16, 552

[56] References Cited UNITED STATES PATENTS 1,756,483 4/1930 Estep 239/D1G. l FOREIGN PATENTS 669,175 12/1938 Germany 239/16 Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Thomas C. Culp, .J r. Attorney-Christie, Parker & Hale ABSTRACT: A family of aerating liquid discharge nozzles, each of which has the feature that it contains no moving parts and includes a hollow body defining a. liquid inlet at one end and an outlet opening at the other end. The body has an internal chamber arranged in communication with both the inlet and outlet ends of the body. Plug means, having substantial length between its opposite end surfaces, is disposed across the chamber adjacent the body outlet end and defines a plurality of grooves which comprise constricted liquid outlet means from the body. The body outlet opening has an area greater than the area of the liquid outlet means. The grooves intermediate their length are increased] in cross-sectional area in a discontinuous manner relative to the adjacent portions of the grooves.

TURBULENT FLOW LIQUID DISCHARGE NOZZLES CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of copending application Ser. No. 784,541 filed Dec. 9, 1968 now US. Pat. No. 3,558,053 as a continuation-in-part of application Ser. No. 691,111 filed Dec. 8, 1967, now abandoned, as a continuation-in-part of application Ser. No. 492,389 filed Oct. 4, I965, now abandoned.

BACKGROUND OF THE INVENTION I readily visible. Aerating fountain heads or nozzles are known,

many of which do not produce sufficient aeration of the water discharged from them. Moreover, existing aeratingv nozzles require critical clearances in the nozzle openings to produce the desired aeration; these clearances either become worn by erosion as the nozzle is operated, or clogged by foreign particles in the liquid passing through the nozzle head, thus adversely affecting the nozzle aerating efficiency.

For efficiency of operation, an aerating fountain nozzle should produce the appearance of discharging a massive stream of water even though the quantity of water actually passed through the nozzle is relatively moderate. When this desired condition is obtained, a small pump may be used, thus resulting in a fountain which is economical to operate. Also, in order that they may be used in populated areas, aerating fountain nozzles should produce as little mist or fine spray as possible; mist is readily transported by slight breeze out of the fountain area to locations where viewers may be positioned. Mist also tends to mask the basic fountain discharge pattern and thus detracts from the aestheticeffect desired inthe fountain.

The design of aerating liquid nozzles is often more of an art than a science, especially where it is desired that the aerated liquid discharged from the nozzle follow a predetermined path from the nozzle throughout a relatively wide range of liquid pressures applied to the nozzle, and where the discharge is to be used to produce an ornamental effect. The use of techniques and principles which are effective in gas mixing noule's, wherein two or more gases are mixed in the nozzle structure and are discharged as a mixture, is practical in only random situations in aerating liquid nozzles because of the widely different physical properties between gases and liquids.

SUMMARY OF THE INVENTION This invention provides a simple, rugged, effective and efficient aerating nozzle which is particularly useful in ornamental fountain arrangements, and also in other applications. The nozzle contains no moving parts which may wear as the nozzle is operated. Moreover, no critically sized apertures are provided in the nozzle, and thus water erosion and the p presence of foreign particles in the water passed through the nozzle have little effect, if any, upon the aerating efficiency of the nozzle. The nozzle produces the appearance of a massive discharge stream even though the actual volume of water passed therethrough is moderate. Moreover, nozzles according to this invention provide liquid discharge patterns which are essentially free of objectionable mist or fine spray and which are readily visible because of the high degree of aeration of the nozzle discharge and freedom from mist.

Generally speaking, this invention provides an aerating liquid discharge nozzle which includes an elongate body defining a duct between a liquid inlet and a liquid outlet opening located at opposite ends of the body. Plug means, having substantial length between its opposite end surfaces relative to the diameter of the duct, is disposed across; the ductadjacent the duct outlet opening. The duct inlet opening has an area which is at least as great as the effective cross-sectional area of the duct at the location of the plug means along the duct. The plug means defines liquid passage means through it, such passage means being comprised of a plurality of grooves formed in the circumference of the plug means at spaced locations around the plug means. Each groove communicates between the opposite ends of the plug means. The passage means has a crosssectional area, at least adjacent the other end of the body, which is substantially less than the cross-sectional area of the duct through the portion of the duct in which the plug means is disposed. The grooves are configured so that the boundary surfaces thereof defined by the plug means intersect at a substantial angle, the groove boundary surfaces defined by the.

walls of the duct. The plug means between adjacent grooves is engaged in surface-to-surface contact with the duct walls. The surface of the plug means adjacent to the other end of the body around the opening of each of the grooves to such surface is substantially normal to the length of the plug means.

Each groove between its ends is enlarged in cross-sectional area in a discontinuous manner relative to the adjacent portions of the groove.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features of the present invention are more fully set forth in the following detailed description of the invention, the description being presented in conjunction with the accompanying drawings, wherein:

FIG. I is a perspective view of the water discharge pattern produced by a nozzle according to. this invention used as an ornamental fountain nozzle;

FIG. 2 is a elevation view, partially in cross section, of a nozzle which produces the discharge pattern shown in FIG. I;

FIG. 3 is a cross section view taken along line 3-3 in FIG.

FIG. 4 is a perspective view of the water discharge pattern produced by another nozzle used as an ornamental fountain nozzle;

FIG. 5 is an elevation view, partially in cross section, of a nozzle which produces the discharge pattern shown in FIG. 4; and

FIG. 6 is a cross section view taken along line 6--6 in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An aerating liquid discharge nozzle 10, shown in FIG. 2, includes an elongate hollow tubular body 11 which defines an elongate, straight, circularly cylindrical duct 12. The duct extends frorri a lower liquid inlet opening 13 at a lowerend I4 of the body to an upper liquid outlet opening 15 at the upper end I6 of the body. The body, adjacent its lower end, defines external threads I7 which adapt the body to be securely connected to a suitably sized, liquid supply pipe, or the like, not shown. Where nozzle 10 is used as an ornamental fountain nozzle, as shown in FIG. 1, the liquid supply pipe to which the nozzle is connected is referred to as a riser pipe and is the means by which water, at suitable pressure, is applied to nozzle 10 for discharge by the noule in a characteristic ornamental discharge pattern 18, shown in FIG. I. The cylinder defined by wall I9 of duct I2 is open across its entire extent at the upper end of body 11.

Plug means 20, having substantial length along the duct between its opposite ends 21 and 22, relative to the diameter of duct 12, is disposed across the duct adjacent the upper end of body I2. In nozzle 10, as shown in FIG. 2, the upper end 21 of the plug means is disposed within the length of duct 12 below body upper end 16. The plug means is pressed or pinned (not shown) into the duct so as to be secured from movement along the length of the duct.

As shown in FIG. 2, plug means 20 of nozzle is defined by a pair of circular, parallelly disposed plugs 24 and 25 disposed across the duct and spaced from each other axially of the duct. Each of the plugs has an axial bore 26, and a single externally threaded rod 27 is passed through the bores of

plugs

24 and 25.

Plugs

24 and 25 are maintained in a predetermined relation relative to each other along the length of rod 27 by nuts 28 threaded onto the rod and engaging upper surface 21 of plug 24, lower surface 29 of plug 24, upper surface 30 of plug 25, and lower surface 22 of plug 25, respectively. Preferably, as shown, the opposite end surfaces of

plugs

24 and 25 are all parallel to each other and are perpendicular to the length of duct 12, at least around the peripheries of the plug. The end surfaces of the plugs, have their end surfaces flat and parallel across the entire extent of the plugs.

Consistent with the foregoing description, plugs 24 and 25 have right circular cylindrical

peripheral surfaces

32 and 33, respectively, which are either of the same diameter as duct 12 or are slightly larger in diameter than the duct, with the result that when the plugs, as interconnected by rod 27 and nuts 28, are disposed in the duct, they have their peripheral surfaces snugly and intimately engaged in contact with duct walls 19 around the entire circumferential extends of the plugs except where the plug peripheral surfaces are recessed to define a plurality of

grooves

34 and 35 in

plugs

24 and 25, respectively.

It is preferred that the distance between end surfaces 21 and 22 of plug means (the combination of plugs 24 and at least along the sidewalls of the duct, be at least one-half the diameter of duct 12; it is apparent that the structure shown in FIG. 2 exceeds this criterion. Since this invention contemplates a nozzle which may have a duct of cross-sectional configuration other than a circle, it is preferred that the thickness of the plug means axially of the duct through those portions of the plug means defining the peripheral grooves be at least onehalf the means transverse dimension of the duct at the location of the plug in the duct. Preferably the duct is straight between its opposite ends through the body of the nozzle. In instances, however, where the duct is other than straight between its opposite ends, it is preferred that the duct for a substantial distance from its outlet end, past the plug means, and toward the liquid inlet opening to the duct be straight and of the same cross-sectional area.

As noted above, a plurality of

grooves

34 and 35 are formed in the

circumferential surfaces

32 and 33, respectively, of

plugs

24 and 25. The grooves extend from the lower surface of each plug to the upper surface of the plug and, in combination with each other, comprise liquid outlet passage means through the duct means which constitute the sole liquid flow communication between duct 12 below plug means 20 to the exterior of nozzle 10. As seen best in FIG. 3, grooves 35 (and also grooves 34 in plug 24) are spaced uniformly apart from each other around the entire circumference of plug 25. The grooves, because they open to the plug circumferential surfaces, cooperate with duct wall 19 to define the corresponding plurality of liquid discharge passages which, in the aggregate, have a total effective liquid flow area which is substantially less than the area of liquid inlet opening 13 or of duct 12 below plug means 20. I

As shown in FIG. 2,

grooves

34 and 35 are tapered along their lengths to have a greater cross-sectional area at their lower ends than at their upper ends. Preferably, the taper of

grooves

34 and 35 is uniform along the entire length of

plugs

24 and 25 respectively. Accordingly, each groove has an inner wall surface 37 which is inclined outwardly of the length of the plug, proceeding upwardly along each of the grooves. As shown best in FIG. 3, groove surface 37 are of semicircular configuration and are concave toward the circumferential surface of the respective plug. Also, each groove has parallel sidewalls 38 which extend from surface 37 radially outwardly of the plug to intersect the circumferential surface of the respective plug at essentially right angles.

The spacing between

grooves

34 and 35 around the circumference of the respective plugs is substantial relative to the width of the grooves; the width of the grooves is the dimension of the groove circumferentially of the plug, whereas the dimension of the grooves radially of the respective plugs is referred to as the depth of the grooves. Preferably, the minimum spacing between each adjacent pair of grooves around the circumference of each plug approximates the width of one of the grooves. As noted above, the plugs have their circumferential surfaces between the grooves engaged intimately in surface-to-surface contact with duct wall 19 along the entire extent of the body traversed by

plugs

24 and 25. This configuration of the grooves, and the intimate cooperation of the plugs with the duct walls, assures that nozzle discharge pattern 18 is as devoid as possible of any mist or spray when the nozzle is operated to produce an ornamental fountain effect. That is, the substantially right-angle intersection between groove walls 38 and duct wall 19, and the surface-to-surface contact of the plugs with the duct walls except across the width of the grooves, eliminates in nozzle discharge pattern 18 the production of thin sheets of liquid as would be encountered if duct walls 38 were merged smoothly or faired into substantial tangency with duct wall 19 at least adjacent the portions of the nozzle where grooves'34 open to the exterior of the nozzle. The presence of thin sheets of liquid in the discharge from nozzle 10 is to be avoided since such sheets rapidly break up, even in the absence of wind, into fine spray or mist.

Preferably, plugs 24 and 25 are identical. In the case of plug 24 (illustrated with respect to plug25), it is preferred that the taper of grooves 34 be such that the configuration of the intersection line of such grooves with upper surface 21 of plug 24 is substantially a semicircle.

As shown in FIG. 2, which illustrates a presently preferred nozzle according to this invention, the exterior surfaces of the nozzle which either border and define the outlet openings of the several liquid discharge passages of the nozzle, or past which liquid emerging from the nozzle must flow, are substantially normal to the lines along which liquid flows in emerging from the nozzle. That is, it is preferred that body upper end surface 16 be normal to the length of duct 12, at least along those portions of the circumference of the body past which the liquid emerging from grooves 34 flows during operation of nozzle 10. Also, it is preferred that plug surface 21 adjacent each of grooves 34 also be substantially normal to the length of duct 12. It is further preferred that the angle of taper of each of

grooves

34 and 35 be on the order of approximately 15 or less. Accordingly, when plug end surface 21 is flat and is perpendicular to the length of duct 12, as is preferred, it is apparent that surface 21 adjacent the opening of each of grooves 34 is substantially normal to the length of each groove. Thus, the exterior surfaces of the nozzle which bound the outlet opening from each of grooves 34, and also those surfaces of the nozzle past which liquid emerging from grooves 34 must flow in discharging from the nozzle, defines a sharp comer either with the surfaces of grooves 34 or with the surfaces of the duct above grooves 34 along which discharge liquid flows during operation of the nozzle. Because liquid emerging from the nozzle passes sharp corners during or after leaving grooves 34, such liquid separates cleanly from the nozzle and does not tend to follow along any of the surfaces either bordering the outlet openings of the grooves or the outlet opening of duct 12. The result is that liquid discharge pattern 18 is essentially free of fine spray or mist.

In order that they may be used to advantage in populated areas, fountain nozzles should produce as little mist or fine spray as possible. Mist is readily transported by a slight breeze out of the fountain area to locations where viewers may be positioned. Also, mist, fog or fine spray tends to mask the basic fountain discharge pattern and thus detracts from the aesthetic effect desired from the fountain. It is apparent, therefore, that nozzle 10 has utility as a water discharge nozzle in an ornamental fountain.

Aeration in the discharge pattern produced by a fountain nozzle is usually the result of turbulence generated in water passing through the nozzle. Fountain nozzle is arranged to produce maximum turbulence in water passing through its structure in such a manner as to minimize the pressure head loss associated with such turbulence generation. Maximum turbulence and aeration, and minimum pressure head loss result in a nozzle which is extremely efficient in terms of the power requirements of the pump used to supply water to the nozzle at a specified mass flowrate. In nozzle 10, aeration and turbulence is produced in substantial part by the gaplike chamber 40 which is provided centrally of plug means by reason of the spacing of

plugs

24 and 25 along spacer rod 27.

It was noted above that in nozzle 10 it is preferred that plugs 24 and 25 be identical. It is also preferred that these plugs be angularly aligned about spacer rod 27 so that the length of grooves 35 in plug 25 are aligned with the length of grooves 34 defined by plug 24. In nozzle 10,

grooves

34 and 35 are defined to be parallel to the length of duct 12. It is within the scope of this invention, however, that

grooves

34 and 35 may be skew, i.e., nonparallel to the length of the duct; in cases where the grooves are skew to the length of the duct, the angle of skew is within a range of from zero to about 30 out of parallel to the length of the duct. In instances where

grooves

34 and 35 have their length skew to the axis of duct 12, the angles of skew of

grooves

34 and 35 preferably are equal and of the same sense angularly about the axis of the duct. That is, if grooves 35 should be defined skew to the axis of bore 26 so that the upper ends of such grooves are displaced clockwise about the circumference of plug 25, relative to the lower ends of the grooves, it is preferred that grooves 34 be defined in plug 24 so that the upper ends of grooves 34 are displaced an equal amount clockwise relative to their lower ends. Thus, since it is preferred that each of grooves 35 has its length aligned with a corresponding one of grooves 34, each aligned set of

grooves

34 and 35 may be regarded as a single groove defining a corresponding one of the liquid outlet passages from duct l2 below plug means 20 to the exterior of nozzle 10. For convenience in the following description, each set of

grooves

34 and 35 is referred to as a composite groove.

Even where the grooves through the plug means of a nozzle according to this invention are skew to the length of the plug, the feature of an approximately right-angled intersection between the groove walls and the duct walls at and adjacent the outlet openings of the grooves is present. That is, the open cross-sectional configuration of grooves 34 at their upper ends is approximately that of a half circle and the diameter of the grooves is substantially less than the diameter of body ll with the result that the walls of the grooves at the point of intersec tion thereof with the inner walls of body lll lie at approximately 90 to the inner walls of the body. Because the value of angle of skew is within a range of from zero to 30 or so, this nearly right-angle relationship between the inner walls of the body and the walls of grooves 34 at the periphery of plug 24 is not significantly modified by virtue of the deviation of the length of the grooves out of exact parallelism to the length of the body.

It is apparent from an inspection of FIG. 2 that each composite groove has a cross-sectional which varies discontinuously along its length. That is, if the cross-sectional area of each composite groove were plotted on Cartesian coordinates as a function of the length of the groove, the graphical representation of such variation would manifest at least one discontinuity. In the the case of the composite grooves encountered in nozzle 10, shown in FIG. 2, two discontinuities would appear on the graphical representation of composite groove crosssectional area as a function of composite groove length; these discontinuities would correspond to the point of intersection of groove 35 with chamber and the point of in tersection of 34 with chamber 40. It is further apparent that the magnitude of these discontinuities would be substantial; that is, if there are eight composite grooves encountered in plug means 20 and the transverse cross-sectional area of chamber 40 is apportioned equally between the composite grooves, it is apparent that the cross-sectional area of the composite grooves between

surfaces

29 and 30 is substantially greater than along the length of either of

grooves

34 and 35.

It is the above-described discontinuity in the cross-sectional area of the composite grooves which results in the generation of a high degree of turbulence in the water flowing through nozzle 10. This turbulence, in turn, results in water or other liquid passed through the nozzle being very highly aerated, largely as a result of turbulent cavitation within the nozzle, as it emerges from the composite grooves. Further, as the discharge liquid moves upwardly from the nozzle in discharge pattern 118, the turbulence in the discharge liquid causes air to be entrained within the liquid further increasing the aeration of the discharged liquid. The result is that nozzle 10 functions to provide a highly aerated liquid discharge. When the discharge liquid is water, the water has a milky-white opaque appearance. Further, the several aerated liquid streams emerging from the grooves 34 of nozzle 10 appear to merge into one another as they rise above the nozzle, with the result that the vertically rising column of liquid present in discharge pattern 18 is hollow for a substantial distance outwardly from the nozzle, thereby producing the illusion of an extremely massive, high-gallonage flow of liquid from the nozzle, when in reality substantially less liquid is discharged from the nozzle than is apparent from an observation of discharge pattern 18.

As an example of a structure according to the foregoing description, an aerating ornamental fountain nozzle has been produced in which counterparts of body II and plugs 24 and 25 are fabricated of polyvinyl chloride. The body is defined by a length of 4 inch, Schedule polyvinyl chloride pipe. In this nozzle, the plugs have a length of 2 inches along the length of the duct, and are spaced 1 inch apart along the spacer rod. The plugs preferably are cut from 2-inch thick polyvinyl chloride block or sheet material. The distance between plug surface 21 and body end surface 16 in this exemplary nozzle is 1 inch. Each of

plugs

24 and 25 defines eight grooves which extend parallel to the spacer rod. Each of the grooves is fabricated by the use of a iti-inch ball end mill and has a taper angle of 15, with the depth of each groove at its upper end being on the order of five-eighths of an inch. This nozzle has been operated to produce an extremely attractive ornamental fountain pattern comprised of a massive column of exceptionally white and highly aerated water. The discharge pattern produced by this nozzle is characterized by an absence of fine mist and spray.

FIG. 4 shows the discharge pattern 50 of another nozzle 52 which may be used to advantage as an ornamental aerating fountain nozzle. An inspection of FIGS. 2 and 5 reveals that

nozzles

10 and 52 are structurally similar in many respects and that nozzle 52 includes a body llll according to the description of the structure of nozzle 10. Except as noted with respect to nozzle 52, the same preferred features and structural characteristics set forth concerning nozzle 10 are also applicable to and are found in nozzle 52.

Nozzle 52, like nozzle 10, includes plug means 54 disposed across the duct adjacent the upper outlet end I6 of body lll. Plug means 20 of nozzle 10 is a composite structure composed of a pair of discrete plugs interconnected by spacer rod 27 and nuts 28. Plug means 54 of nozzle 52, however, is of unitary construction and preferably is fabricated from a cylindrical piece of polyvinyl chloride having a peripheral surface 55 configured, in cooperation with the cross-sectional shape and size of duct 112, to fit snugly within body llll, so that the peripheral surface of the plug is intimately engaged with duct walls 19 except in those locations of the plug where its peripheral surface 55 is recessed to define

grooves

56 and 57 and a circumferential recess 58 around the plug intermediate the opposite ends 59 and 60 of the plug. Preferably, recess 58 is centered at the midlength of plug 54 and has a depth radially of the plug which is substantial relative to the radius of the plug. The presence of circumferential recess 58 in the plug divides the plug into upper and lower enlarged diameter portions 62 and 63 of equal diameter which are interconnected by a central reduced diameter portion 64. Radially outwardly of central portion 64, plug portions 62 and 63 define opposing surfaces 65 and 66, respectively, which preferably are parallel to each other and are perpendicular to the central axis 67 of the plug. Equal numbers of

grooves

56 and 57 are defined in plug circumferential surface 55 along the lengths of plug enlarged diameter portions 62 and 63, respectively. Accordingly, each of grooves 57 communicates from duct 12 below the plug to plug recess 58, and each of grooves 56 communicates from recess 58 to the exterior of nozzle 52.

In contrast to the grooves present in nozzle 10,

grooves

56 and 57 are not tapered. That is, the distance from plug axis 67 to the nearest limit of

grooves

56 and 57 is constant along the length of the grooves. Preferably, as. shown in FIG. 6,

grooves

56 and 57 are of substantially semicircular configuration concave to the peripheral surface of plug 54. Also as shown in FIG. 6,

grooves

56 and 57 are aligned parallel to plug axis 67 and corresponding ones of the grooves formed in plug portions 62 and 63 are aligned with each other. Accordingly, aligned ones of

grooves

56 and 57 may be regarded as a single composite groove having a portion intermediate its length of substantially greater cross-sectional area than the remainder of the length of the groove. That is, viewing each aligned set of

grooves

56 and 57 as a composite groove within the meaning set forth above, it is apparent that each composite groove in nozzle 52 has a portion intermediate its length in which the cross-sectional area of the groove is increased in a discontinuous manner relative to the remaining portions of the length of the groove. Thus, recess 58 provides a turbulence generating and aeration inducing discontinuity of substantial magnitude in the length of the composite grooves present in nozzle 52.

Unitary plug means 54 of nozzle 52 is disposed in body 11 so that its upper surface 58 is coplanar with the upper surface 16 of body 11.

' As in the case of nozzle 10, plug upper surface 58 at least adjacent the openings of above-described 56 to such surface, and also those portions of body upper end surface 16 which cooperate with plug end surface 59 to bound and define the outlet openings of grooves 56 to the exterior of the nozzle, are substantially perpendicular to the lengths of grooves 56 and make sharp comers with the groove boundary surfaces defined by plug 54 and by body 11. The presence of the sharp comers bounding the outlet openings of grooves 56 to the exterior of the nozzle assures that the turbulent liquid emerging from the nozzle during use thereof separates cleanly from the nozzle structure and does not result in the generation of fine spray or mist in discharge pattern 50. Also, as in nozzle 10, the

sidewalls of grooves 56 at least adjacent the outlet end of the nozzle intersect the duct walls at a substantial angle, thereby eliminating the existence of thin sheets of liquid in the discharge from the nozzle immediately adjacent its outlet end;

as a practical matter, by reason of the above-described nature of nozzle 52, the sidewalls of

grooves

56 and 57 intersect duct walls 19 at a substantial angle (approximately 90) along the entire extent of the lengths of such grooves. Accordingly,

grooves 56 provide the sole outlet openings from the interior of nozzle 52 below plug 54 to the exterior of the nozzle. The total net effective liquid flow area provided by composite grooves through the plug means 54 is substantially less than the area of nozzle inlet opening 13 and of the duct below the plug means.

It has been found that when nozzles and 52 are constructed to have the same general common dimensions and are operated to discharge liquid at equal mass flowrates, nozzle 52 produces a discharge pattern 50 which is discernibly higher (assuming a vertical disposition of the nozzles in each case) than discharge pattern 18 produced by nozzle 10. The discharge pattern associated with nozzle 52 has a less massive appearing column of rising liquid than is found in discharge pattern 18 for nozzle 10. The aeration of the discharge from both nozzles, insofar as can be determined from visual inspection, is essentially equal. Accordingly, it is apparent that nozzle 52 is particularly useful as an aerating, ornamental fountainnozzle which may be disposed vertically, or at an angle to a vertical reference line, in a pool of a fountain installation. ln those instances where

nozzles

10 or 52 are used as aerating, ornamental fountain nozzles, it is desired that the nozzles be disposed in the fountain pools so that only a small portion of their length is located above the surface of the pool.

As an example of a nozzle having the properties shown in FIG. 2, an effective fountain nozzle may have its body defined by a length of 4 inch Schedule polyvinyl chloride pipe, and its plug also fabricated of polyvinyl chloride. The plug, in this exemplary nozzle, has an overall length of 5 inches with the central circumferential recess of the plug extending for approximately lk inches along the length of the plug.

Grooves

56 and 57 are parallel to the length of the plug and are aligned with each other. The grooves have a depth of 0.60 inches and may be defined in the plug by the use of a 34-inch ball end mill.

Nozzles according to this invention operate to produce substantial and significant degrees of aeration in liquid discharged from them, without reliance upon specific dimensional relationships or critically sized dimensions or openings. Moreover, as is apparent from the foregoing description, such nozzles have no moving parts. Accordingly, in order to maintain desirable operating characteristics provided by these nozzles over a long time, it is not necessary that the nozzles be operated in conjunction with a filter for removing sediment and particulate matter from the liquid supplied to the nozzle. This characteristic of the present nozzles adapts such nozzles to use in those industrial installations, and other applications different from that of ornamental fountain nozzles, where aeration is desired. For example, nozzles according to this invention can be used to advantage in aerating and oxidizing liquid sewage. The presence of sediment or particulate matter in sewage introduced to the nozzle does not readily lead to degradation or destruction of the aerating properties of the nozzle, especially where the liquid introduced to the nozzle is of such nature as to permit the nozzle to be made of erosion resistant polyvinyl chloride or the like. Also, other uses for present nozzles will be readily apparent to those persons having skill in the art to which this invention pertains. Moreover, nozzles according to this invention operate to produce highly aerated discharges over a wide range of applied liquid pressures.

The invention has been described above with reference to presently preferred embodiments thereof. Workers of ordinary skill in the art to which this invention pertains will recognize from the preceding description that the structure of the two described embodiments may be altered without departing from the scope and spirit of this invention. For example, workers in the art will recognize that a plug having the unitary aspect of plug 54 of nozzle 52 may be provided in nozzle I0. Conversely, such workers will also recognize that the plug of nozzle 52 may be of the built-up construction illustrated in FIG. 2 if desired. Also, it will be apparent that the discontinuity in the area of each groove in the present nozzles may be provided separately for each groove rather than in common to all the other grooves of the nozzle; that is, instead of providing an annular chamber 40, for example, common to

composite grooves

34, 35, each groove may have its own enlarged diameter area defined in its length, it being understood that the transition from each groove to such enlarged diameter portion is across a shoulder. Accordingly, the foregoing description, presented for the purposes of example and illustration, should not be regarded as limiting the scope of this invention.

What is claimed is:

1. An aerating liquid discharge nozzle comprising an elongate body having opposite open ends defining a duct therethrough between a liquid inlet opening defined by one open end of the body and the other open end of the body; and plug means having substantial length between opposite ends thereof relative to the diameter of the duct disposed across the duct adjacent the other open end of the body and secured from movement along the length of the body; the plug means being engaged around its periphery with the inner walls of the duct; the plug means have a plurality of liquid flow passages defined therethrough at locations proximate the circumference of the plug means and communicating between the opposite ends of the plug means; the liquid flow passages having an aggregate cross-sectional area, at least adjacent the other end of the body, substantially less than the cross-sectional area of the duct at the location of the plug means in the duct; each liquid flow passage between its ends being enlarged in cross-sectional area discontinuously relative to the adjacent portions of the passage; the surface of the plug means adjacent the other end of the body peripherally of the opening of each passage to said surface being substantially normal to the elongate extent of the passage.

2. A nozzle according to claim ll, wherein the surface of the plug means adjacent the other end of the body is spaced inwardly along the duct from the other end of the body.

3. A nozzle according to claim 1, wherein the surface of the plug means adjacent the other end of the body is substantially coplanar with the other end of the body.

4. A nozzle according to claim 1, wherein the plug means has a length along the duct at least along the extent of the liquid flow passages which is at least equal to one-half the mean transverse dimension of the duct at the location of the plug means in the duct.

5. A nozzle according to claim 1, wherein the liquid flow passages are disposed parallel to the length of the duct at the location of the plug means in the duct.

6. A nozzle according to claim 1, wherein the duct at the location of the plug means therein and for a substantial distance toward the one end of the body is straight and of constant area.

7. A nozzle according to claim 1, wherein the liquid flow passage provide the only communication internally of the nozzle between the liquid inlet opening and the liquid outlet openmg.

8. A nozzle according to claim ll, wherein the liquid flow passages are comprised by a plurality of grooves formed in the circumference of the plug means, the grooves and the inner ;walls of the body cooperating to define the liquid flow passages which have said substantially smaller aggregate cross-sectional area.

9. A nozzle according to claim 8, wherein the plug means has an upper portion and a lower portion spaced from the Mlsurface engaged with the duct walls and a number of grooves equal to sad plurality defined in its circumferential surface to communicate between the opposite ends of said portions, said chamber extending radially of the plug means to the circumferential surfaces of the upper and lower portions.

10. A nozzle according to claim 9, wherein the chamber has a cross-sectional area transverse to the duct which is substantially greater than the areas of the grooves at the openings of the grooves to the chamber.

11. A nozzle according to claim 9, wherein the surfaces of the plug means upper and lower portions opening to the chamber are substantially normal to the length of the plug means at least around the openings of the grooves to the chamber.

112. A nozzle according to claim 9, wherein the plug means upper and lower portions are defined by separate plugs spaced from each other along the duct.

13. A nozzle according to claim 12, including means connected between the plugs for defining and maintaining a predetermined spacing between the plugs along the duct.

14. A nozzle according to claim 9, wherein the chamber is defined by a circumferential recess formed in a unitary plug.

115. A nozzle according to claim 9, wherein the length of each groove in each of the upper and lower portions of the plug means is substantially greater than the depth of the groove radially of the plug means.

16. A nozzle according to claim 9, wherein each groove in each of the upper and lower portions of the plug means is tapered.

117. A noule according to claim 16, wherein each groove has its maximum cross-sectional area at the end thereof toward the one end of the body.

18. A nozzle according to claim 9, wherein each groove in the upper portion of the plug means has its length aligned with the length of the corresponding groove in the lower portion of the plug means.

19. A nozzle according to claim 8, wherein the spacing circumferentially of the plug means between each adjacent pair of grooves is substantially equal to the width of one of the grooves.

20. A nozzle according to claim 8, wherein the walls of each groove at least at the ends of the grooves adjacent the other end of the body intersect the duct walls at a substantial angle.

21. A nozzle according to claim 20, wherein the substantial angle is approximately @2 3 UNITED STATES RATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 a 396 Dated OCCOber l2 1971 Inventor(s) John O. Hruby, Jr

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 62, before "presence" delete --p-. Column 3, line 24, for "extends read --extents--;

line 36, for "means" read --mean--;

line 68, for "surface" read --surfaces--. Column 5, line 38, after "each" read -aligned-. Column 7, line 36, for "above-described" read --grooves--. Column 8, line 14, for "inches" read -inch--. Column 9, line 33, for "passage" read .--passages--.

Signed and sealed this 6th day of June 1972.

(SEAL) Attest:

EDWARD M.F'L3TCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims

2. A nozzle according to claim 1, wherein the surface of the plug means adjacent the other end of the body is spaced inwardly along the duct from the other end of the body.

7. A nozzle according to claim 1, wherein the liquid flow passage provide the only communication internally of the nozzle between the liquid inlet opening and the liquid outlet opening.

8. A nozzle according to claim 1, wherein the liquid flow passages are comprised by a plurality of grooves formed in the circumference of the plug means, the grooves and the inner walls of the body cooperating to define the liquid flow passages which have said substantially smaller aggregate cross-sectional area.

9. A nozzle according to claim 8, wherein the plug means has an upper portion and a lower portion spaced from the upper portion along the duct on opposite sides of an annular chamber intermediate the length of the plug means, the plug means upper and lower portions each having a circumferential surface engaged with the duct walls and a number of grooves equal to sad plurality defined in its circumferential surface to communicate between the opposite ends of said portions, said chamber extending radially of the plug means to the circumferential surfaces of the upper and lower portions.

12. A nozzle according to claim 9, wherein the plug means upper and lower portions are defined by separate plugs spaced from each other along the duct.

15. A nozzle according to claim 9, wherein the length of each groove in each of the upper and lower portions of the plug means is substantially greater than the depth of the groove radially of the plug means.

17. A nozzle according to claim 16, wherein each groove has its maximum cross-sectional area at the end thereof toward the one end of the body.

21. A nozzle according to claim 20, wherein the substantial angle is approximately 90*.