US3552652A

US3552652A - Atomizing nozzle

Info

Publication number: US3552652A
Application number: US758866A
Authority: US
Inventors: Leon D Greenwood
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1968-09-10
Filing date: 1968-09-10
Publication date: 1971-01-05
Anticipated expiration: 1988-01-05

Abstract

An atomizing nozzle which is mounted in and rotated by an air blast to disseminate liquid agricultural chemicals, and which is effective to provide a predictable degree of atomization over a wide range of flow rates.

Description

United States Patent Leon D. Greenwood Lansing, Mich. Appl. No. 758,866

Filed Sept. 10,1968

Inventor Patented Jan. 5, 1971 Assignee FMC Corporation San Jose, Calif. a corporation of Delaware ATOMlZlNG NOZZLE 12 Claims, 7 Drawing Figs.

US. Cl 239/77, 239/214.3, 239/224 Int. Cl A0ln 17/08 Field of Search 239/214,

[56] References Cited UNITED STATES PATENTS 1,492,986 5/1924 l-lurd 239/214.13 1,640,418 8/1927 Marr 239/214.19X 1,869,384 8/1932 MacLachlan..... 239/224 1,944,043 1/1934 Titmas 239/214.13 2,457,067 12/1948 Perretti 239/214.13 3,130,677 4/1964 Liebhart.. 239/77UX 3,138,328 6/1964 Glasby 239/223X Primary Examiner-M. Henson Wood, Jr. Assistant Examiner.lohn .1. Love AttorneysF. W. Anderson and C. E. Tripp ABSTRACT: An atomizing nozzle which is mounted in and rotated by an air blast to disseminate liquid agricultural chemicals, and which is effective to provide a predictable degree of atomization over a wide range of flow rates.

PATENTEUJAN 5197i 3.552.652

' sum 1 or 3 I N V EN TOR. g LEON D. GREENWOOD J IW ATTORNEYS PATENTED JAN 5197:

saw a nr 3 @NN in #q @n U nH-HF-HP ATTORNE YS SHEET 3 OF 3 I NVENTQR. LEON D. GREENWOOD B Mm mm g No. 0 om N52. 3. mo. QN I 8 om 5 m9 9 y s Q fl mfh. kw L AT TORN E YS 2. Description'ofthe PriorArt ATOMIZING'NOZZLE BACKGROUND or THE INVENTION I. Field of Invention The present invention concerns spray nozzles and particularly concerns a nozzle which atomizes a liquid agricultural chemical for entrainment in an air blast generated by an air carrier sprayer such as the type used in orchards. A relatively recent development in spraying is to employ a concentrated liquid chemical atomized in the air blast of an air carrier sprayer, rather than use a weak -"dilut ed spray. With the diluted spray application, the foilage is highly wetted'and a substantial proportion of the chemicalcontent of the spray is lost because much of the spray dripsfoff the trees. With the concentrated spray application the'object is to uniformly distribute droplets rather'than to wet the foilage. The term ultra low volume" has received comm'on'usag'e for very high concentrate applications. In this mannerless dripping occurs, and a minimum amount of chemicalsare used to obtain spray protection equal to the protectionof'a conventional spray application. An indication of this atomization requirement will be recognized-from the fact that a concentrated spray application,

of less than .5 gallons per acre is possible with the present nozzle, in the contrast to the conventional dilute spray application I which may require from 50 to 500 gallons per acre. To

achieve these results, the 'concentratedsprayliquid'mu'st be uniformly atomized and distributed infthe air blast to assure .maximum, coverage of all foilagewit hin the rangeof the air blast. It has been found that ordinary orifice type'spray heads cannot be used inthis type of spraying because they cannot :provide the necessary atomization,-easily clog, and are not well adapted to precise metering to the'jdegree requiredfor concentrated spray application. Further, many of these types of liquid chemicals are e'xtremelyfcorrosive to metal or contain insoluble solids which are left behind when the carrier fluid evaporates. It is thus considered mandatory that the nozzle be provided with apertures and other features to drain off .the chemical when the nozzle is idle. However, the requirement of very fine atomization and-,efficient nozzle operation is difficult to achieve simultaneously with drainage features.

'Atomizing nozzles of thetype ivhich'er'nploy centrifugal dispersion via a rotating memberare known in the prior art. For example, Hurd 1,492,986 discloses'an atomizing nozzle which meters fuel oil into an'oil burner. It is alsoknown to provide external drive vanes to provide centrifugal distribution of material into an air blast enveloping the nozzle, as in the Bals patent 2,738,226.

Insofar as the present objectives areconcerned, prior art,

nozzles are generally unsuitable for their relative complexity and inconvenient disassemblyfor cle'aning or repair, and are more specifically unsuitable in that'they'do not provide for drainage when idle, and will not achieve uniform atomization throughout a wide range of flow rates. a

SUMMARY or THE invention A spinning type of atomizing -noz zlefis provided with a splash guard ring arid a flow distributor which cooperatively optimize atomization over a wide-range of flow rates and prevent loss of spray material through drain holes that function to discharge the spray material when the nozzle is not in operation.

BRIEF DESCRIPTION OF TnEo Awmos FIG. 5 is an enlarged schematic section of the discharge end portion of the nozzle shown in FIG.-4.-

FIG..6 is an enlarged section taken along lines 6+6 on FIG. 4, and particularly illustrates the 'flowpaths in thenozzle.

- FIG. 7 is an enlarged schematic secti n, similar to FIG. 5.

but illustrating a different flow condition.

DESCRIPTION OF THE PREFERRED'EMBOPIMENT One useful embodiment for theatomizing nozzle I0 (FIGS. 1 and 2) is in a field sprayer of the'type which generates a high velocity air blast toward trees on other vegetation to be treatedThe nozzle 10 is mounted in an air blast (indicated by the air blast flow arrows'12) and is connected to a supply line 14. For a reason-mentioned later in connection with FIGS. 5 and 7, the nozzle (FIG. 4) extends rearward from a plane in- ,cluding the-front edge 13 of a blower. outlet shroud I5. By

means of the nozzle 10, a concentratedspray liquid metered into the line 14 is atomized and distributed in the air blast. In conventional spraying methods, ,a diluted liquid chemical is supplied under pressure to a-plurality of orifice-type spray heads which produce relatively nonuniform spray droplets that are carriedby the air blast onto thetrees to be'trea ted. In

I the present system, the highly concentrated liquid chemical is atomized intoa spray mist of small droplets projected from the open end of a rotatable discharge belll6L-The mean diameter,

of the droplets is a function of the-rotational speed of the discharge bell.

Since the conventional spraying'operation is wetter and i t t cannot reach some areas from a-stnglespraymg position, it IS usual tooverspray so that the accumulated spray flows and drips, and it is common'to spray from more than one position- -all with the object of maximizing the probability of complete coverage. In the present system using controlledparticle size and concentrated spray liqdidL-stibstantially all of the spray material remains on the target since the spray has little tendency to-drip. Further, the .spraytends'to envelop the target by following turbulent air flows, and some vegetationcan therefore be sprayed with a'singl'e pass or from astatic position.

The atoniizing nozzle l0.o erate's. in conjunction with centrifugal force to provide a fine atomization and dispersionof the liquid chemical. For this pu rpose,'t he nozzleincludes a fixed tubular neck 18 which is threadedlinto thesupply line I4, and a body 20 that is driven by the air blast 12 for rotation about an axis 24. The flow rate off'the spray concentrate supplied bythe manifold is adjustablebyconventional means, namely, a valve V (FIG. 2) which regulates the output of a pump P into the lines 14. The spray. concentrate is supplied 1"- from a tank. T, and a pressure regulator R is in abypass line which returns excess spray liquid to' -the tank. The valve body 20 is a part of discharge bell 16 and-thus spins the bell so that a thin film of the spray concentrate-is maintained on the inner concave surface '17 of the discharge belLThe spray concentrate is conducted to said surfa'ce'by means including a flow distributor 22 that is mounted centrally within and rotates with the discharge bell. Thus, all parts visible in FIG. I that are carried by the nonrotatable tubular neck- 18 rotate about the axis 24. Theabove-described rotation is effected by six vanes 26 of airfoil shape that project radiallyoutward from a hollow hexagonal portion 28 of the body 20. :Each vane is pivotally adjustable about a mounting bolt 29 so that its angle of incidence relative to the air blast is'adjust'able. Therefore, with an air blast of given velocity, the rotational speed of the nozzle can be altered by adjusting the vanes" 7 Due to the spinning of the discharge bell 16, the film of spray concentrate on the surface'f l7, is accelerated outward over a circumferential edge 17alinto the air blast 12, thus forming the spray material into droplets and dispersing the droplets in the 'air blast. By selecting the appropriate spinning speed for the nozzle, even-with the highest incoming flow rate the fluid film on thesurface l7can -be made very thin. thus producing small spray droplets of very'unifo'rm' size.'The size of the spray droplets produced by themozzle may'bccontrolled, within a desirable'degree of uniformity, by regulating the liquid flow rate and/or the rotational speed of the nozzle.

With particular reference to FIG. 4, the tubular neck 18 is provided with partially threaded counterbore 30 that receives the threaded inner'end portion of a hollow spindle 32. The spindle conducts'liquid from the line 14 onto the flow distributor 22, and supports both the fixed and the rotatable elements of the assembly. Elements which remain nonrotatable on the spindle 32 include ball bearings 34 and 35, and a spacer 36 which contacts only the inner races of the bearings. Also nonrotatable is a ring 38, that retains an O ring 40 in abutting relation with an inner end surface of the tubular neck 18, and two Belleville washer located at 42 between the retainer ring 38 and the bearing 35.

The Belleville washers are held in axial compression, and the bearing 34 abuts a stop ring 44 that is mounted in a groove of the spindle 32. Accordingly, the O-ring 40 is biased simultaneously into sealing engagement with the end surface of the neck 18, and the peripheral surface of the spindle 32. The bearings are thus maintained in a given axial location on the spindle. Because of the compressible Belleville washers and the fixed axial positions of the bearings relative to the spindle, a close running fit is adjusted, during assembly, between the tubular neck 18 and the hexagonal body 28 to minimize the intrusion of contaminants that might interfere with proper operation of the bearings. Thus, the tubular neck 18 is provided with a cylindrical skirt 46 that is in circumscribing relation with a cylindrical projection 48 on the adjacent end of the rotating hexagonal body 28, and the passage between these relatively movable parts forms a labyrinth which is maintained at about .010 ofan inch.

Axial retention of the hexagonal body 18 relative to the bearings 34 and 35 is provided by spaced split lock rings 50 and 52, and a radial flange 54 ofa rotating tube 56 that rotates with the body 20. The lock rings are mounted in grooves in the body and straddle the outer race of the bearing 34. The radial flange 54 is relieved so as to prevent contact with the inner bearing race, and is provided with an end groove mounting an O-ring 58 which seals the interface of the flange and the outer bearing race, while biasing the outer race into firm contact with the rear lock ring 52. The O-ring simultaneously biases the rotating tube 56 into firm contact with the forward lock ring 50, thus compensating for manufacturing variances.

The rotating tube 56 has an elongate tapered sleeve portion 60 with most of its bore slightly larger than the outside diameter of the spindle 32 so as to prevent contact between the fixed spindle and the tapered, rotating sleeve. The outer wall of the tube 56 is tapered in order to cause any misdirected fluid that might contact the wall to flow rearward away from the discharge bell 16 by centrifugal force which urges the fluid toward the larger diameter portion. To complete the isolation of the bearings from contaminants outside the rotating tube 56, the end wall of the tapered sleeve '60 dynamically seals with the Teflon seal ring 62 which is clamped onto the spindle 32 by a split steel ring 64. Physical contact of the Teflon ring 62 with the rotating tube 56 is not functionally essential. A close running clearance along the interface is adequate for elimination of the particles of material which occasionally are exposed to that area. A helical compression spring 66 abuts the lock ring 52 and the outer race of the bearing 35. This spring, which furnishes less force than the Belleville washers, places a preload on the bearings to remove excess running clearance, thus maintaining precise positioning of the dynamic seal surfaces as well as maintaining preset clearances between

element

46 and 28 as previously described.

The discharge bell 16 is formed integrally with the hexagonal body 28, and at the base, of the bell 16 at its junction with the body 28 are radial drain apertures 70. One drain aperture extends between each flat surface of the body 28 into an interior annular overflow chamber 72 that is. partially defined by the radial flange 54 and the tapered sleeve 60 of the tube 56. The drain apertures 70 are for the purpose of draining away the highly corrosive spray liquid when the nozzle is not in operation. Under some unusual operating conditions when spray liquid might enter the chamber 72 because the flow rate might be improperly proportioned to the rotational speed ofthe nozzle, the drain apertures can also provide an escape path to bleedoff and prevent the liquid from contaminating the bearings. Thisespecially important with the low friction dynamic seal which will not prevent contaminant passage under pressure. g 7

When the nozzle is operating at a highldis'charge rate, there is a flow reversal tendency which if unchecked, will cause part of the spray material that should issiietf'ro m the discharge bell 16 to travel out the drain apertu 70, ln the presently disclosed embodiment, such flow eversal is primarily prevented by a splash guard ring 7 nd' it 's particular cooperation with the flow distributor 22 in banner presently described. I n The concave wall surface 17 of-the discharge bell 16 merges with a central cylindrical bore 78. The bore 78 terminates at an inwardly projecting radial wall or dam 80, and theflow distributor 22 is removably pressfitted into the bore 78 in abutting relation with the dam. Manual removal of the flow distributor 22 can be effected by engaging a hooklike tool, not shown, in an aperture 82 and pulling the flow distributor outward, after which the distributor and the thus'accessible interior ofthe nozzle can be cleaned. g

As previously indicated, one function of the flow distributor 22 is to circumferentially distribute liquid which is delivered through the spindle 32. To this end, the inwardly facing central portion 84 of the flow distributor 22 is of generally conical or cuspidal form, and the vertex of the cone is centered in proximity to the adjacent end 'portion of the spindle 32, thereby permitting adhesive contact with the fluid issuing from the passage through the spindle,'in order to insure even distribution to all portions of the reservoir area. The wall surface 85 defining the central portion 84 of the flow distributor is concave, and the vertex circumferentially distributes" the liquid delivered through the spindle onto'the concave wall to be progressively urged-outward toward the concave wall 17 of the discharge bell 16. Centrifugal force aids in distributing the liquid evenly over thewall surface 85 of the flow distributor.

The conical wall surface 85 (FIGS. 4 and 6) merges with a plurality of circumferentially spaced, longitudinal fingers orsplines 86 which extend inward to the dam 80. In cooperation with the wall defining the bore 78in the discharge bell, ad jacent fingers 86 define radially inwardly open U-shapedfluid reservoirs 88 which are blocked at their ends by the dam 80.

In order to provide a seat for the guard ring 74, the inwardly I facing surfaces of the fingers 86 are relieved to a common depth. An O-ring 90, which isrnounted in a peripheral groove with ample running clearance between their relatively movable confronting surfaces.

In operation, a nozzle for the previously described concentrated spray application might be required to deliver between about .02 of a gallon per minute to 2m more gallons per minute, depending upon the crop being sprayed, the type of spray material, and other spraying conditions. Efficient atomization at low flow rates from less than .02 gallons per minute up to medium flow rates of about .2 of a gallon per minute is satisfactorily accomplished without employing splash guard ring 74. However, the guard ring must be utilized with flow rates of approximately 2 gpm or morev With the splash guard in place, the nozzle will give good results throughout the entire range of flow rates, because of the operational characteristics next described.

In operation, the spindle 32 (P16. 5) conducts a column" of liquid spray concentrate onto the pointed end of therapidly revolving flow distributorf22. The liquid is thus smoothly dispersed and retained by adhesion over the whole of the concave wall surface 85.-'lt will be understood that FIGS. 5 and 6 are schematic and illustrate the fluid flow for only a narrow radial sector of the total-circular flow pattern, and that because of centrifugal and frictional forces the fluid has a helical flow component, rel'ativeto wall surface 85.

Due to adhesion and frictional contact, the boundary layer of the fluid on the concave flow distributor wall 85.is rapidly accelerated around the axis 24 and outward along the wall; However, the surface fluid remote'from the wall surface 85 is less rapidly accelerated, due to viscous drag. This condition is 7 not unfavorable at low flow rates and low rotational speeds of the nozzle 10 because cohesive attraction among the particles of fluid on the wall 85 is not exceeded. Therefore, part of the fluid on the flow distributor wall 85 flows outward between the splines 86 onto the concave wall 17 of the discharge bell 16, while another part of the fluid travels slightly rearward at I02 along the inner surfaces Qfthe'splines, thence outward into the fluid reservoirs 88. These flows are illustrated in FIG. 5 except for the flow shown in broken lines which applies to another condition.

The fluid on the discharge bell surface 17 accelerates outward and over the discharge edge 170 where it separates into droplets 104 that become entrainedin theair blast l2 and are reservoirs 88 will not flow outward into the discharge bell until a fluid head is established which will overcome cohesive forces within the fluid and adhesive forces between the fluid and the walls of the reservoirs. Thus, the fluid builds up in the reservoirs until a sufficient pressure gradient is established to carried onto the target. Meanwhile, the fluid at 106 in the I overcome the above noted forces, atwhich time fluid flow is formed filaments emanating from the sheet of fluid in the discharge bell are believed to facilitate the formation of the uniformly sized droplets achieved with the described structure because it has been found that the particle size can be changed by substituting a distributor with a different number of splines. If, for example, a six splined distributor is substituted for the standard one with twelve splinesfsix filaments emanate from the edge-17a rather than twelve. Since the fluid flow rate has not changed, the diameters of the filaments are larger and the resultant droplets have larger diameters. I

At higher flows, around the middle of the stated flow range or about .2 gpm, the surface or theresultingly thicker film of area so that the liquid particles at ll0 arenot drawn through the reservoirs 88 into the annularchamber72. Meanwhile, the beveled face 94 of the splash guard ring 74 confines the flow path of these particles so that they either travel into the discharge bell and mix with the liquid therein, or impinge and mix with the liquid in the reservoirs'88. Because the rotational speeds of the particles and the inner-surfaces of the splines 86 about the axis 24 are not widely different at medium flow rates, the particles tend more to flow into the reservoirs 88 rather than to splash off the radial surfaces of the splines.

At the highest stated flow rates, about 2 gpm or higher, the

same above-described splashing action occurs to a greater,

degree because of the greater difference in'rotational speeds between the water particles and theradial surfaces of the splines. Moreover, since the outer layer ofliquid has very little tangential acceleration, the liquid flowing onto the innersurfaces of the splines 86 reverses as shown at 114 (FIG, 7) onto the face 94 of the splash guard ring 74, and the liquid flowing into the reservoirs 88 splashes in the same general rearward direction. in both cases, the splashing and reversing liquid is blocked by the beveled face 94 of the splashguard ring 74 and is returned toward the apex of the flow distributor 22.

Splashing tends to overflll the reservoirs88 if the rotational speed of the nozzle is not high enough for the maximum desired flow rate. This condition is readily perceived and corrected, because the liquid passes rearward beyond the dam 80 and flows out the drain holes 70 onto the exterior surface of the discharge bell. When the rotationalspeed of the nozzle is correctly set for the desired highest-flow'rate by either adjusting the nozzle driving vanes 26 or by regulating the air blast 12, little or no liquid will be lost through the drain holes at any flow rate.

Under actual operating conditions, however, it is inevitable" tube 56 and may lie overthe interface of'the Teflon seal.62

and the tube. Suchliquid works its way rearward in favor of the larger diameter of the tube, and if" collected in large enough quantities will periodically exit from the drain holes 70 while the nozzle is in operation. When the nozzle is idle, any liquid on the tube 56 gravitates to the bottom of the tube and toward its lower end portion, and then drops through the liquid on the flow distributor wall'85 will not accelerate to the 1 full speed, of nozzle rotation. Therefore," there is a speed difference between the surface liquid and the rotating splines 86, and this results in the internal splashing indicated by the discontinuous liquid particles at 110 (FIG. 5) in addition to the normal, uninterrupted flow along the concave face 85 of the flow distributor 22. Loss of this'splashing liquid through the drain holes 70 and exposure of. the seal interface between the Teflon ring 62 and the endwall of the sleeve 60 are prevented by the splash guard ring 74 since it confines splashed droplets within the forward ends of the chamber 72.

it should be explained at this point that by positioning the leading edge 17a (FIG. 4) of-thenozzle't flush with the front edge 15 'of the blower housing, the drain holes are in a higher pressure area .of the air blast than the open end of the discharge bell. Further, other positions of thenozzle relative sure being measured at the drain holes. in order to enhance the pressure differential, the preferred placement of the nozzle, as described, positions the drain holes in a higher pressure lowermost drain holes 70, or out through bell -l7, depending upon the mounting position of the ato'mizing nozzle 10.

A further aspect of the nozzleoperation is that the reservoirs 88 have a marked effect in stabilizing the flow of liquid into the discharge bell 16. Without theirmetering action, the distribution of liquid from the flow distributor tends to be less smooth and predictable, and this adversely affects the resultant mist of droplets. For thisreason, and because of the filaments of liquid formed from the reservoirs 88 in the manner previously mentioned, the flow distributor splines 86 materially assist in the uniform degree of atomization achieved with the nozzle 10. At the sametime, the guard ring 74 and its cooperative relation with=the splines, flow distributor 22 and drain holes is important in efficiently achieving a wide range of flow rates withoneinozzle structure, and in providing a durable and easily maintained unit especially adapted to handle highly concentrated .and corrosive liquid spray materials.

Although the best mode contemplated for carrying out the present invention has been herein shown and described, it will be apparent that modification and variation maybe made without departing from.what is regarded to be the subject matter of the invention as set forth in the appended. claims.

lclaim:

1. An atomizing nozzle comprisinga fixed tubular spindle connected to a source of liquid chemical under pressure, a

hollow body rotatably mounted onsaidsplndle and including a discharge bell defining an inwardly converging concave wall surface merging with a cylindrical chamber, a generally conical flow divider mounted in said discharge bell and having its vertex disposed within said chamber, and a splash guard ring mounted in said chamber and circumscribing the apex portion of said flow divider, said ring defining with said apex portion an outwardly divergent annular fluid passage in general lateral alignment with the inner end portion of said concave wall surface.

2. A nozzle for atomizing liquid agricultural chemicals comprising a fixed tubular spindle connected to a source of liquid chemical under pressure, a hollow body rotatably mounted on said spindle and including an outwardly flaring discharge bell, said discharge bell being provided with an internal concave wall merging at the circular outer edge of a counterbore larger than said spindle, the end wall of said counterbore forming a radially inwardly projecting dam; a flow distributor in said bore, said distributor including a cuspidal central flow divider having its vertex disposed within the opening in the adjacent end portion of said spindle, a plurality of splines parallel to the axis of said spindle and extending in both directions beyond said vertex, said splines encircling said flow divider and having inner ends abutting said dam; and' a] splash guard ring in peripheral contact with the inner surfaces of said splines, said ring having a beveled outer end face confronting said flow divider and cooperatively defining therewith an outwardly divergent fluid passage in general lateral-alignment with the inner portion of said concave discharge be wall.

3. An atomizing nozzle for liquid agricultural chemicals comprising a fixed tubular spindle defining an axis of rotation, means for directing an enveloping air blast along said spindle, an outwardly flared discharge bell having a hollow body portion mounted on said spindle for rotation about said axis, said body portion having a cylindrical inner chamber merging with said discharge bell and receiving the adjacent end of said spindle, a flow distributor centrally mounted in the chamber of said discharge bell for rotation therewith, said distributor including a generally conical wall symmetrical about said axis and converging in the same direction as said discharge bell, means for delivering a column of liquid chemical through said spindle onto the apex of said flow distributor, a splash guard ring mounted in said chamber and having an annular wall confronting the conical wall portion of said flow distributor to cooperatively define therewith an annular flow passage outwardly diverging from said axis, said flow passage delivering said liquid onto the inner surface of saiddischarge bell, and means connected to said discharge bell and reacting against said air blast to rotate said discharge bell, said flow distributor and said splash guard ring about said spindle axis.

4. A nozzle for atomizing liquid agricultural chemicals comprising a fixed tubular spindle connected to a source of liquid chemical, a hollow body rotatably mounted on said spindle and including an outwardly flaring discharge bell, said discharge bell being provided with an internal wall merging at the circular outer edge of a counterbore larger than said spindle, the end wall of said counterbore forming a radially inwardly projecting dam; a flow distributorin said bore, said distributor including a cuspidal central flow' divider having its vertex disposed within the opening in the adjacent end portion of said spindle, a plurality of splines parallel to the axis of said spindle and extending in both directions beyond said vertex, said splines encircling said flow divider and having inner ends abutting said dam; and a splash guard ring having an annular wall confronting the base portion of said flow distributor and cooperatively defining therewith an annular flow passage outwardly diverging from said axis.

5. Apparatus according to claim 4, wherein said hollow body defines an annular overflow chamber around the open end of said spindle, said dam and the adjacent end portions of said splines being located in said chamber, and wherein said hollow body includes a plurality of circumferentially spaced radial drain holes communicating with atmosphere and said overflow chamber.

6. Apparatus according to claim 5, and a sealing ring mounted on said spindle and located within said overflowv chamber, and a tube carried by said rotatable body and masking that portion of said spindle which is located in sajdoverflow chamber, said tuber having an end surface in sealing relation with an end surface of said sealing ring.

8. Apparatus according to claim 7, and means confining an enveloping air blast axially along said spindle, a plurality of vanes circumscribing said body, and a radially extending pivot connecting each vane to said body, theangles of incidence of said vanes thus being adjustable relative to the air blast to rotate the nozzle at predetermined speed in an air blast of given velocity. i

9. A nozzle for atomizing liquid agricultural chemical scomprising a fixed tubular spindle connected to a source ofliq uid chemical under pressure, a hollow body rotatably mounted on: said spindle and including an outwardly flaring discharge bell, said discharge bell being provided withan internal concave wall merging at the circular outer edge of acounterborelarger than said spindle, the end wall of said counterbore forming a radially inwardly projecting dam; a flowdistributor in said bore, said distributor including a cuspidal central flow divider,

a plurality of splines parallel to the axis of said spindle, said splines encircling said flow divider; and a splash guard ring in peripheral contact with the inner surfaces of said splines, said.

ring having a beveled outer end face confronting said flow divider and cooperatively defining therewith an outwardly divergent fluid passage.

10. A nozzle for atomizing liquid agricultural chemicals comprising a fixed tubular spindle connected to a source of liquid chemical, a hollow body rotatably mounted on said spindle and including an outwardly flaring discharge bell, said I discharge bell being provided with an internal wall merging at the circular outer edge of a counterbore larger than said spindle, the end wall of said counterbore forming a radially inwardly projecting dam; a flow distributor in said bore, said dise tributor including a cuspidal central flow divider, a plurality of splines parallel to the axis of said spindle, said splines encircling said flow divider and having inner ends abutting said dam; and a splash guard ring having an annular wall confronting the base portion of said flow distributor and cooperatively defining therewith an annular flow passage outwardly diverging from said axis.

11. Apparatus according to claim 7, wherein the nozzle is.

positioned in an air blast flowing axially along said spindle, a plurality of vanes circumscribing said body, and a radially extending pivot connecting each vane to said body, the angles of incidence of said vanes thus being adjustable relative to the air blast to rotate the nozzle at predetermined speed in an air blast of given velocity. 4

12. Apparatus according to claim 1, wherein said flow divider is of cuspidal form and the apex portion thereofis disposed within the opening in the adjacent end portion of said spindle.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,552,652 Dated January 5, 1971 Inventor) Leon D. Greenwood 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 24, before "contrast" cancel "the". Column 3, line 11, "washer" should read washers Column 8, line 1 "tuber" should read tube Signed and sealed this 23rd day of May 1972 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patent FORM F'O-OSD (D-69) USCOMMJDC 60376.

- I. a nun-nun" -muvn-s n...-

Claims

1. An atomizing nozzle comprising a fixed tubular spindle connected to a source of liquid chemical under pressure, a hollow body rotatably mounted on said spindle and including a discharge bell defining an inwardly converging concave wall surface merging with a cylindrical chamber, a generally conical flow divider mounted in said discharge bell and having its vertex disposed within said chamber, and a splash guard ring mounted in said chamber and circumscribing the apex portion of said flow divider, said ring defining with said apex portion an outwardly divergent annular fluid passage in general lateral alignment with the inner end portion of said concave wall surface.

2. A nozzle for atomizing liquid agricultural chemicals comprising a fixed tubular spindle connected to a source of liquid chemical under pressure, a hollow body rotatably mounted on said spindle and including an outwardly flaring discharge bell, said discharge bell being provided with an internal concave wall merging at the circular outer edge of a counterbore larger than said spindle, the end wall of said counterbore forming a radially inwardly projecting dam; a flow distributor in said bore, said distributor including a cuspidal central flow divider having its vertex disposed within the opening in the adjacent end portion of said spindle, a plurality of splines parallel to the axis of said spindle and extending in both directions Beyond said vertex, said splines encircling said flow divider and having inner ends abutting said dam; and a splash guard ring in peripheral contact with the inner surfaces of said splines, said ring having a beveled outer end face confronting said flow divider and cooperatively defining therewith an outwardly divergent fluid passage in general lateral alignment with the inner portion of said concave discharge bell wall.

3. An atomizing nozzle for liquid agricultural chemicals comprising a fixed tubular spindle defining an axis of rotation, means for directing an enveloping air blast along said spindle, an outwardly flared discharge bell having a hollow body portion mounted on said spindle for rotation about said axis, said body portion having a cylindrical inner chamber merging with said discharge bell and receiving the adjacent end of said spindle, a flow distributor centrally mounted in the chamber of said discharge bell for rotation therewith, said distributor including a generally conical wall symmetrical about said axis and converging in the same direction as said discharge bell, means for delivering a column of liquid chemical through said spindle onto the apex of said flow distributor, a splash guard ring mounted in said chamber and having an annular wall confronting the conical wall portion of said flow distributor to cooperatively define therewith an annular flow passage outwardly diverging from said axis, said flow passage delivering said liquid onto the inner surface of said discharge bell, and means connected to said discharge bell and reacting against said air blast to rotate said discharge bell, said flow distributor and said splash guard ring about said spindle axis.

4. A nozzle for atomizing liquid agricultural chemicals comprising a fixed tubular spindle connected to a source of liquid chemical, a hollow body rotatably mounted on said spindle and including an outwardly flaring discharge bell, said discharge bell being provided with an internal wall merging at the circular outer edge of a counterbore larger than said spindle, the end wall of said counterbore forming a radially inwardly projecting dam; a flow distributor in said bore, said distributor including a cuspidal central flow divider having its vertex disposed within the opening in the adjacent end portion of said spindle, a plurality of splines parallel to the axis of said spindle and extending in both directions beyond said vertex, said splines encircling said flow divider and having inner ends abutting said dam; and a splash guard ring having an annular wall confronting the base portion of said flow distributor and cooperatively defining therewith an annular flow passage outwardly diverging from said axis.

6. Apparatus according to claim 5, and a sealing ring mounted on said spindle and located within said overflow chamber, and a tube carried by said rotatable body and masking that portion of said spindle which is located in said overflow chamber, said tube having a tapered exterior surface converging toward said sealing ring and an end surface in sealing engagement with an end surface of said sealing ring, the larger end portion of said tapered surface being radially aligned with said drain holes.

7. Apparatus according to claim 5, and a sealing ring mounted on said spindle and located within said overflow chamber, and a tube carried by said rotatable body and masking that portion of said spindle which is located in said overflow chamber, said tuber having an end surface in sealing relation with an end surface of said sealing ring.

8. Apparatus according to claim 7, and means confining an enveloping air blast axiAlly along said spindle, a plurality of vanes circumscribing said body, and a radially extending pivot connecting each vane to said body, the angles of incidence of said vanes thus being adjustable relative to the air blast to rotate the nozzle at predetermined speed in an air blast of given velocity.

9. A nozzle for atomizing liquid agricultural chemicals comprising a fixed tubular spindle connected to a source of liquid chemical under pressure, a hollow body rotatably mounted on said spindle and including an outwardly flaring discharge bell, said discharge bell being provided with an internal concave wall merging at the circular outer edge of a counterbore larger than said spindle, the end wall of said counterbore forming a radially inwardly projecting dam; a flow distributor in said bore, said distributor including a cuspidal central flow divider, a plurality of splines parallel to the axis of said spindle, said splines encircling said flow divider; and a splash guard ring in peripheral contact with the inner surfaces of said splines, said ring having a beveled outer end face confronting said flow divider and cooperatively defining therewith an outwardly divergent fluid passage.

10. A nozzle for atomizing liquid agricultural chemicals comprising a fixed tubular spindle connected to a source of liquid chemical, a hollow body rotatably mounted on said spindle and including an outwardly flaring discharge bell, said discharge bell being provided with an internal wall merging at the circular outer edge of a counterbore larger than said spindle, the end wall of said counterbore forming a radially inwardly projecting dam; a flow distributor in said bore, said distributor including a cuspidal central flow divider, a plurality of splines parallel to the axis of said spindle, said splines encircling said flow divider and having inner ends abutting said dam; and a splash guard ring having an annular wall confronting the base portion of said flow distributor and cooperatively defining therewith an annular flow passage outwardly diverging from said axis.

11. Apparatus according to claim 7, wherein the nozzle is positioned in an air blast flowing axially along said spindle, a plurality of vanes circumscribing said body, and a radially extending pivot connecting each vane to said body, the angles of incidence of said vanes thus being adjustable relative to the air blast to rotate the nozzle at predetermined speed in an air blast of given velocity.

12. Apparatus according to claim 1, wherein said flow divider is of cuspidal form and the apex portion thereof is disposed within the opening in the adjacent end portion of said spindle.