US2605142A - Spray device - Google Patents

Description

July 29, 1952 2 SHEETS SHEET 1 Filed Oct. 25, 1948 5 W a F a 6 7. k Ema: V 23%? m o z v mg /7 /4 A17 z a a aw ma 3w av @w v a fi f; 7 l 1 A l J a l I w:

July 29, 1952 H GOLD ET AL 2,605,142

SPRAY DEVICE Filed Oct. 25, 1948 2 SHEETS-SHEET 2 Patented July 29, 1952 SPRAY DEVICE HaroldGold and David M. Straight, 7 Cleveland, Ohio Application October 25, 1948, Serial M56322 16 Claims. (Cl. 29,9114) (Granted under the act of March 3, 18:83, as

. 1 V This invention relates to improvements in spray devices and more particularly concerns spray devices of a character adapted to produce a finely atomized spray as in supplying fuel into the combustion chamber of a turbo-jet aircraft engine, or the like.

In practical applications, such as in supplying atomized fuelto the combustion chamberof a turbo-jet engine or the like, flow rate of the liquid supply to the spray nozzlemay vary over a Wide range from zero to arelatively high rate. However, throughout the time of actual liquid atomization, the quality of atomization must remain substantially constant I for optimum end results, as in the attainment of a proper combustible mixture of the atomized liquid fuel and air in the combustion chamber of the engine.

The most desirablespray pattern for uses such as that suggested, as well as other. uses, comprises a hollow cone shaped spray stream of the atomized liquid. For maximum efficiency in admixture of air with the atomized spray stream of liquid fuel, it is desirable that the spray stream angle be as wide as practicable at any fuel flow rate throughout the range of flow rates provided for in any given installation.

In the attainment of these desirable results, in a simple and efficient manner, the liquid supplied to the spray orifice is caused to assume a high velocity vortex flow immediately upstream from the orifice so that the whirling motion of the liquid persists as the liquidescapes through the orifice and sprays into the space beyond the orifice.

The present invention is especially directed to the means whereby not only is an effective hollow cone shaped spray pattern attained, but the spray cone angle is also maintained substantially constant throughout the operating range of liquid supply flow rates. g

It is therefore an important object of the present invention to provide improved means for so controlling the supply of fluid in a spray nozzle assembly that a substantially constant hollow cone shaped atomized spray stream of substantially constant cone angle is attained throughout a relatively wide range of flow rates in operation. J r j I Another object of the invention is-to provide in a nozzle assembly for effecting a finely atomized hollow cone shaped spray stream means affording a-swirl chamber of constantsize immediately upstream from the spray orifice and wherein substantially constant liquid velocity is maintained throughout a wide range. of liquid flow rates in the liquid supply system.

amended AprilBO, 192s; 370V 0. c.1157) A further object of the invention is to provide in ,a finely atomizing spray'nozzle construction improved control ,means automatically responsive to variations in fluid supply-pressures in the course of flow rate variations to control ;delivery of the fluid to the spray orifice in a manner to maintain constant atomizing efficiency.

Still anotherobject of the invention is to provide novel pressure sensitive control means n a spray nozzle device which operates not only to shut off thenozzle completely in the absence of predetermined minimum fluid pressure, but is also operative throughout a substantial fluid nozzle embodying features of the invention;

Figure 2 is a horizontal sectional view taken substantially on line II-H of Figure 1;

Figure 3 is an enlarged fragmentary vertical sectional view through the spray nozzle orifice and swirl chamber immediately upstream'therefrom with schematic illustration of the fluid action in developing a predetermined spray pattern;

Figure 4 is a fragmentary vertical sectional view through a modified form of flow control means according to the invention;

Figure 5 is a fragmentary longitudinal sectional view through a further modification; r

Figure 6 is a fragmentary longitudinal sectional view through still another modification embodying the features of the invention;

Figure '7 is a longitudinal sectional View through yet-another.modification;

Figure 8 is-a fragmentary longitudinal sectional view through still. another modification; and

Figure 9 is a fragmentary longitudinal sectional view through another modification.

Asshown on the drawings:.

In one form of spray nozzle-assembly embodying the features of the invention, a spray nozzle l5 (Figs. 1, 2, and 3) comprises a tubular casing or housing it which may serve as an. adapter to facilitate mounting of the nozzle and carries a nozzle frame tube ll. At an intermediate portion of the tube ll, it is provided with a radial flange or collar I8 which is threadedly engaged Within the end of the casing tube 16 with one portion of the nozzle frame tube ll disposed interiorly of the housing tube l6 and the remaining portion of the tube l1 projecting beyond the end of the housing tube. Within the outwardly projecting or forward portion of the nozzle frame tube I1 is a nozzle plug H! which is fitted in fluid tight relation within the bore of the tube l'l.

Within a stepped recess 20, coaxially in the outer end of the plug I9 is mounted an orifice plate or disc 2| having a fixed axial spray orifice 22 therethrough and held removably in place by means such as a retaining ring nut 23 screwed into the outer enlarged portion of the recess 20. Inwardly of the orifice disc 2| and closed by the disc is a cylindrical chamber 24 which is of substantially larger diameter than the orifice 22 and of a predetermined depth. Directed tangentially into the chamber 24 is a series of preferably equidistantly annularly spaced fluid delivery ports 25.

Fluid entering the chamber 24 by way of any one -or more of the ports 25 under pressure swirls about-within the chamber 24 anddevelops a vortex'due to its velocity flowing toward the orifice 22, substantially as indicated at V in Fig. 3. At

the orifice 22,'the fluid due to its high velocity coaxial whirling motion escapes into the orifice as a thin film of more or less cylindrical tubular shape whirling spirally outwardly along the periphery defined by the orifice and then breaks from the outer rim of the orifice as a whirling finely atomized hollow cone-shaped spray stream identified at S in Figs. 1 and 3. The length or depth of the swirl chamber 24 determines the angle of the spray stream S by determining the length of the vortex V an'd' hence the angle of the vortex which is reflected in the spray stream angle. Since the area and length of the swirl chamber 24 remain fixed, the length of the vortex V remains constant and thus the spray stream S maintains substantially the same cone angle.

According to the present invention means are provided for assuring that the vortex velocity in the swirl chamber 24 will remain substantially constantithroughout a substantial range of fluid flow'rates in the supplyto the nozzle as will ocmand. To this end, each of the deliveryports 25 is preferably of a .difierent cross sectional flow area graduated in size according to a predetermined range of fluid supply flow rates. A separate fluid supply channel 21 leads to each of the respective delivery ports 25 and may be in the form of a longitudinally extending separate peripheral groove formed in the external periphery of the plug [9. The supply grooves 21 extend short of each opposite end of the plug l9 and are isolated one from the other by the fluid tight interengagement between the periphery of the plug and the embracing wall of the nozzle.

frame tube I1. Each of the supply duct grooves 21 communicates by way of a communication port 28in the plug 19 with a cylindrical fuel supply chamber 29 formed as a coaxial bore extending in from the inner end of the plug and terminat- .cur during operation in accordance with various variable factors such as variations in fluid decylindrical chamber 29 corresponding to the length of the piston 30. By preference, the communication ported area is adjacent to the inner or open end of the cylinder 29 so that the forward end of the cylinder affords a substantial clearance for movement of the piston 38 into a position clear of the communication ported area of the cylinder.

Means are provided for normally biasing the piston 30 into the communication port closing relation thereof. Herein such means comprise a tension spring 3i connected at one end to a stem 32 extending coaxially rearwardly from the piston 30, the stem being provided with an interhooking end notch 33 for this purpose. The opposite end of the biasing tension spring 3| is hooked onto a cross rod 34 supported by the rear end portion of the nozzle frame tube H. The spring 3! is of such length and tension that it acts normally to draw the piston 30 rearwardly against an abutment shoulder 35 which may be in the form of a ring shaped member'threadedly secured into the rear end of the plug [9 in concentric constricting relation to the rear end or mouth of the cylinder 29. In this position the piston 30 fully closes all of the communication ports 28 and also coacts with the shoulder member 35 to seal the nozzle against leakage of fluid during shutdown. T

In operation, the biasing spring 3| holds the piston 30 closed until a predetermined fiuidsupply pressure is exerted against the piston to unseat the piston from the valve seat abutment 35 until at least one of "the communication ports 28 is uncovered for passage of the-fluid under pressure therethrough and through the associated supply duct 21 to thecommunicating delivery port 25. By preference all of the communication ports 28 are of the same relatively large size so as to afford relatively unrestricted flow of fluid from supply to the associated port 25. However, the respective communication ports 28 are arranged in progressively spaced relation from thevalve seat and abutment shoulder 35 in the order of;size of 'theassociated delivery ports 25, from the smallestto the largest. That is, the communication port 28 which is connected with the smallest of'the delivery ports 25 is disposed, substantially as disclosed in Fig. 1, to be uncovered flrst in order as pressure develops in the fluid supply. Then as pressure increases the next communication port will be uncovered to supply the next delivery port 25 in order of size, and so on until at maximum fluid pressure all of the communication ports 28 have been opened to admit fluid to all of the delivery ports 25. Th crossrsectional flow area of each of the radial communication ports 28 and the longitudinal duct or groove passages 21 is large enough in each instance to avoid throttling of the fluid, so that the pressure at the entrance to each of the tangential delivery ports '25 is equal to the pres- 'sure in the chamber area upstream from the piston 30 when the respective communication ports 28 are uncovered by forward movement of the plungeror piston 30 under the influence of supply fluid pressure.

Since the tangential delivery ports 25 are of progressively larger cross sectional flow area, it will be apparent that while the flow rate of the fluid may increase, the velocity with which the fluid is delivered by the respective delivery ports 25 will remain substantially constant throughout the full range of flow rates in the fuel supply. Consequently, while the volume of fluid in the. fvortex V will increase proportionately as the flow rate of the fiuidsupplyv increases,- its. velocity of rotation will remainsubstantially constantand this will be reflectedinsubstantially constant spray stream. cone .angle; although the volume. of fluid discharged throughtheorifice 22 will vary proportionately. The diameterof the orifice. .22. isv such that throughout the. entire range of flow rate, it will neverrflllbut always maintain ahollow whirling stream;

At low flowrates itis not only importantfor good atomization that. a. sufiiciently high pressure dropbemaintained. at the ports. 2.5; but it is equally important that the .flow of fluid be properly directed within the nozzleso that a high rotationalvelocity is: maintained in the swirl chamber 24. Liquid that leaks past the piston 38 will tend to 'fiowinto'the succeeding radial communication ports 28; from there into the larger tangential delivery ports 25 and thus reach the swirl chamber at low velocity. If this leakage flow is a substantial percentage of the total flow through the. nozzle'atomization will be poor. In order substantially tofl'avoid this condition Without requiringextremely close fltting of the piston'39 in the cylinder 29, the radial communication openings 28 that feed the smallest tangential delivery ports 25 are located a sufficient distance rearwardly of the next large radial communication ports-28 so that there is "a great enough blockage .of the path to the communication openings 28 that-feed the-larger tangential delivery ports 25 to reduce'pistonleakage to a negligible amount during low flow rates.

At higher flow rates, piston leakage is not an important factor. For this reason the radial communication ports 28 that feed the larger tangential delivery ports 25 may be located closer together, and even to the extent that while each port remains independent there may be a slight overlap in uncovering of successive ones by the piston 36.

Pressure relief between the forward end of the piston 39 and the closed end of the cylinder 29 is afforded through a relief port or vent 37 which opens coaxially through therear of the swirl chamber 24 and due to the hollow core of the rotating fluid in the vortex V and as it passes on through the orifice 22 and in the spray stream .8, direct communication with the atmosphere in the space into which the nozzle discharges is effected.

This communication of the forward side of piston 3% with the atmosphere into which the nozzle discharges renders the pressure gradient between the cylinder chamber, forwardly of piston 32!, and the atmosphere independent of variations in atmospheric pressure, and hence the prcssure drop across the tangentially disposed openings 25 and the velocity of discharge through the openings 25 is made independent of variapiston identified as 38 is provided with a stem 3% carrying at its rear end a retainer flange disc 39 against which the rear end ofla coiled compression spring 4!!- bears while the forward end of the spring bears against the :endofthe nozzle plug 19. In this arrangement it is practicableto eliminate the inner orrearward exten sionportion of the nozzle frame tube ll. In this arrangement the spring 40 is of course of such supply duct 50.

size and tensionthatit will normally 1101a the piston 30 closed" in sealingabutment with the shoulder 35 but will yield in response to .predetermined fluid'pressure to permit forward movement of the piston 30' for uncovering thesuccessive communication ports 28 in proportion to theflow rated the fuel supply; the-spring maintaining the. piston 30' in a state of equilibrium in each pressure increment attained as the flow rate varies-from time to time in'the fluid supply.

Inthe modification of Figure 5,-a nozzle assembly. 4| is. shown as including a body or adapter tube into the forward endof which issecured a nozzle frame tube 43 which carries fixedly therein a nozzleplug M. -At its forward end the-plug 441s of substantiallythe samegconstruction as the plug IS in. Fig. 1, including a swirl chamber 45 closed at'its forward. or open end by an orifice plate 41 providing a spray orifice 48. Leading into theswirl chamber 45 is a series of tangential" fluid delivery ports 59 of graduated sizes. The smallestof the tangential delivery ports '49 communicates with a supply duct groove 59 in the periphery of the plugiifi and to which leads at its rear end a radial communication port 5| which opens through the plug it into a cylinder 52 into which fluid is supplied from the supporting tube 42. The communication port.5l is normally closed by apiston. 53 which is urged by biasing means such as a coiled-compression spring 54 into seating relation: with a shoulder 55' with which the piston forms a fluid seal. When the fluid supply pressureireaches a predetermined value. the spring '54 is overcome and the. piston-53' moves forwardly until .it is stopped influid sealing relation against a forward shoulder 5'5 and in which position the communication port 5| is opened to afford a free flow of fluid therethrough and the supply duct 50 to the smallest of the tangential delivery ports 49. 4

Opening movement of the piston 53 also exposes a port 58Jleading to a duct 59 which communicates at its other end through a port 68 with a pressure chamber 6| at the'forward end of the cylinder 52. When the pressure of the fluid supply increases sufficiently to overcome the loaded biasing spring 54', a second piston 6-2 is unseated from. a shoulder 63 against which it-is normally biased into fluidsealing relation. As

64 by which thefluidyis'conducted to respective supply ducts 65 for delivery to the respective tangential delivery ports of respectivelygraduated sizes larger than. the minimum size. of the delivery port which communicates with the Itwill be understod that the arrangement of the delivery ports 49 will be substantially similar to the arrangement shown in Fig. 2 for the delivery ports 25. Communication between the piston chamber and atmosphere is afforded by a relief vent 66 serving the same purpose as the reliefvent 3'! in Fig. l.- The arrangement of Fig. 5 affords a multiple liquid seal during shutdown and provides certain advantageous features as to fluid control. It is also-significant that means is provided whereby leakage past the control piston at low flow rates, during which onlyv the smallest passages 4-9 are functioning, is entirely eliminated.-

-The modification of'Figure 6 provides a {spray 7 me nozzle 61 which is in several respects similar to Figures 1 and 5 in that it affords a conically shaped atomized spray stream of substantially constant size and velocity despite substantial variation in the fluid supply rate. To this end, the nozzle 61 comprises-a supporting or adapter tube 68 into the forward end of which is secured a nozzle frame tube 69 carrying a nozzle plug 19 therein similarly as the nozzle plugs 19 and 44 previously described. A swirl chamber H of fixed size at the forward end portion of the plug 19 is closed by an orifice plate 12 similarly as in the previously described formsof the invention. One or more supply duct groves 13 in the periphery of the plug 19 communicate constantly with the supply passage rearwardly of the plug 19 and each of the supply ducts communicates freely by way of a radial port 14 with a fluid supply chamber 15 adjacent to but spaced from the swirl chamber II. When the fluid pressure reaches a predetermed value, a piston 11 is unseated from a retaining and sealing shoulder 18 at the rear end of the supply chamber 1-5 and moves rearwardly under the influence of the fluid pressure within a cylinder 19 in which it is slidably contained. A suitable biasing means such as a compression spring 89 normally urges the valve 11 against its sealing seat 18 but is adapted to be overcome by predet'ermned fluid pressure against the piston 11 so as to open a succession of radial communication ports 8! which lead to respective supply groove ducts 82 in the periphery of the plug to feed a series of respective delivery ports 83 of graduated sizes communicating tangentially with the chamber H. The relationship and operation of the communication ports 8| and the delivery ports 83 is preferably substantially similar to the operation of the corresponding ports in the forms of the invention shown in Figures 1 and 5. The rear end of the spring 80 is retained by an abutment plug 84 closing the rear end of the cylinder 19. A vent passage 85 to atmosphere communicates with the rear end of the cylinder 19. M

In some circumstances it may not be desired to shut off the fluid supply line completely from the orifice during shutdown, and in such event the form of nozzle l5 shown'in Figure '7 may be utilized. The construction and arrangement of this'nozzle is identical with that in Figure 1 with the exception that the smallest of the tangential delivery ports 25 into the swirl chamber 24 communicates by way of a channel duct 81 directly with the supply passage in the rear portion of the nozzle frame tube 11-. The remaining tangential delivery ports 25 are under the control of the spring biased piston valve 39 similarly as in the case of the nozzle I5 of Figure 1. Since the details of structure of the nozzle I5 are substantially identical with those of Figure 1, identical reference numerals designate the same parts.

In the form of the invention shown in Figure 8 a nozzle assembly I5" is in most respects substantially the same in details of structure as the nozzle assembly l5 of Figure 1. Substantial identity of parts is indicated by use of identical reference numerals to identify such parts. In the nozzle assembly [5", however, a different form of control valve and piston arrangement is utilized. To this end, a piston 88 is provided for reciprocal sliding engagement within the cylinder 29 for normally closing the radial communication ports 28 in the plug l9 and which swirl afford communication between the supply ducts I extension 9| which is hooked onto the forward end of the tension spring 3|. The threaded detachable coupling afforded by the short stem 89 and the coupling 99 enables the assembly about the stem 89, serving as a guide, of a disc valve and pressure plate 92 which is normally urged into separated relation to the rear end of the piston 88 by biasing means such as a coiled compression spring 93. In the normal, fluid pressure free condition of the piston 88 wherein it is biased into port closing relation by the spring 3!, the disc valve 92 seats sealingly against a shoulder 94 provided by a retaining and distribution ring 95 threaded into the upper end of the plug I9. In this closed, sealing condition of the valve disc 92,it shuts off from the fluid supply a radial port 91 through the retainer 95 and communicating with an annular forwardly opening distribution groove 98 in the retainer and which in turn communicates with a passage duct 99 feeding the supply duct 21 which in turn feeds the smallest of the tangential delivery ports or the swirl chamber 24. The rear end of the piston 88 is in the fully closed condition of the piston engaged against a stop and sealing shoulder I09 afforded by the inner peripheral margin of the retainer ring 95 which for this purpose slightly overlaps the mouth of the cylinder 29.

When the liquid pressure of the fluid supply rises above a preset value, the auxiliary valve plate 92 is unseated from the shoulder 94 and moves against the bias of the spring 93 until it uncovers the communication port 91 and seats against the rear end of the piston 88. This, of course, starts the spraying action of the nozzle [5". A continued rise in the fluid pressure acting against the plate 92 causes the plate and piston 88 to move as a unit in opposition to the bias of the spring 3| for successively opening the axially spaced communication ports 28 by which the successively larger delivery ports 25 are fed with fluid in proportion to increase in fluid pressure and thus increased flow rate, operation proceeding as with the nozzle [5 of Figure 1. Any slight leakage past the plate 92 into the hollow piston 88 may drain off by way of a vent opening lOi through the forward face of the piston into the forward vented portion of the cylinder 29.

A nozzle assembly l5' as shown in the modification of Figure 9, comprises in most respects a similar construction as that disclosed in Fig. 1, as indicated by identification of similar parts by the same reference numerals. In this form, similarly as in the nozzle assembly l5 of Figure 8, a control valve arrangement is utilized wherein a preliminary or auxiliary valve member is initially motivated by development of pressure in the fluid supply system over a preset value and thereafter the auxiliary member engages with and moves jointly with a principal control member as the flow rate increases. This affords a relatively sensitive fluid pressure responsive control for low flow rate and a more resistant fluid pressure response at higher'flow rates. In the valve assembly l5", an auxiliary fluid pressure responsive piston I 92 is movable Within a suitable control range between a shoulder I03 and a principal control valve piston I04, the auxiliary piston I92 being normally urged sealingly against shoulder I93 by means such 'as aerial-45 9 a biasing tension spring I05 hooked onto the rear end'of aconnectings'tem IN on the auxili ary piston. The shoulder I03 is provided'by a retaining ring 108' secured into the rear end of a nozzle plug f9 and formed with a forwardly opening annular distribution "groove I09 with which communicates a port II'0 leading to the cylindrical guide bore for the piston I02 afforded by the retainer I08. The communication port II is normally closed by the piston I02 and is adapted to be opened when the piston I 02' is urged from its seat I03 by development of pressure above alfprest valve in' the supply system rearwardly of the piston I02 Increase. in fluid supply pressure stung upon the rear face of the piston I02 drives the same against the rear face of the piston I04 which isslidably' re'ciprocably bearinged in a cylinder 29 in the plug I 9' and is normally urged by a preloaded comprssionspring- [l1 actingbetween thQDistdn 104 and the fc irward blind epd of' the cylinder 29 against ashoulder H2 afforded by an; overlapping inner marginal portion-of the retainer ring' I08 at the mouth of the cylinder 29}. By preference the rear face of the piston I04 which opposes the piston I'02 isformed with a cavity or recessed seat to receive the piston I02 when the latter is forced against the piston I04 by fluid pressure. A vent opening H4 in the head of thepiston IE4 relieves any pressure that might develop in the operation of the pistons and 7 also drains off any fluid that may possibly leak past the piston I02.

In the operation of the nozzle assembly I', after'thesupply. pressure of fluid in the chamber affordedat the rear end of the nozzle frame tube II develops to a value greater than that preset by tension of the spring. I05; the auxiliary piston H22v is unseated from'i'ts sealing and retaining shoulder I03' and opens the communication .port'liflr This sets the/spray function of thefnozzl'e into operation by way of the smallest o'f'th'e tangential delivery ports 25 into the. swirl chamber 24. Upon increase of the; fluid pressure to a point where the auxiliary piston I02 seats against the rear face of the principal control piston I04,- andfurther development of pressure to overcome the combined resistance of the springs I05 and III, the control piston I04 is driven forwardly until the first of the communication ports 28 is opened to increase the volume of fluid sprayed from the nozzle, and this action continues progressively asthe fluid supply pressure increases, or decreases in proportion to decrease in fluid supply pressure and return of pistonsto closing relation to the successive fluid communication ports 28 and eventually the starting communication port H0.

In any ofthe forms of the invention shown in Figures '7, sand 9, the compressiontype of con-' trol'spring as identified at 40 in Fig. 4 may. of course, be utilized by obvious modification.

It will" be observed that in the illustrations of: Figures 1, l, 5 and 6, the relationship of the mov-j able parts-to the associated parts in the respective nozzle assemblies disclosed is in a'state of at least partially. open, operative condition; In the forms of Figures 7, 8 and 9, on the other hand, the nozzles are shown intheshutdown condition or at least prior to development of fluid.v supply pressure'greater than the preset value which must be attained. before the control'valve or pis"-' ton'structure will be unseated-for operation.

Where-desirable,-such well known expedients as elastic gaskets between sealingly cooperative preset value, the state 10 parts may be'utilized in the respective nozzle assemblies. In the more or less schematic i11us= trations in the drawings, such expedients have been omitted;,-although in order to makeup for slight manufacturing variations or tolerances, such expedients may be desirable in actual pram tice.

Fr m the foregoing it will be apparent that-in all of the various forms of the invention disclosed a wide rangeofsupply fluid flow rates can be accommodated with a substantially constant pressure drop across-the noz'zl'e' an theattainnient of this substantially constant pressure drop across the nozzle excessive pressures are avoided in the fluidsupply line to thenozzle orificeat high fl'ow'rates but suflicient energy is available at low now'rate ror obtaining a fine spra any' flow rate 'w'i thi'n the operating rangenoz'Zleth-e control valve or plunger 'offth" assernbly is positioned by the intractidn fluid pressure forces and the spring biasing-r s thateqnili'briurn' is reached betweent m. If the new rate increases from'a predetermined If the'floW rate-8r the supply fluid decreases, the opposite action occurs, By selection of the appropriate nozzle assembly for any" particular r muin eflici'ency in'operati'on nevertheless utilizing 'the's'ali invention. I 1 Itrnay be noted that in all formsiof the iii .tion' disclosed} the spray orifice is recessed to. a substantial depthfrom thetip of the nears he'd mg. :Theridse of 'the recess is set so that 'a sin 1 clearance exists between'it and the outlet'sur'face' of the spray cones flhesp'ray coneitself is not sharply defined; Afine mist-fans out from the surface of thespray cone. This finemist fiills the small clearance between the spray-coneand the ridge of the recess,- forming. aabarrier' against small particles ofcarbon that are" forme'dnur-ina combustion of. the finely atomized fluid'. carbon deposits on the relatively cool surtaces cfthe" mom-man: disrupt the spray lei-tines around: the G fie shown, carbon-m y' esp-teat on 'tlie r1 g outside of? the recess; but depo'siting" anys-ign'ific q orifice, thus assuring ertendedopera nozzlle without-mterfereno'e from carbon eposits'.

The invention described herein may be nianu-f fa'ctured and used by orfortheGovernmen I the United States of America for governmental purposes without the payment eff anyroyalties thereono th''rf j I'tfwill', or can ,be finder'stoodthat va details in the present disclosurefnay b w as var ed ease-ew de-enemas a e at principles of this invention. and itis theireforei not the ms the pa granted hereon otherwise than necessitated=bythe scope areaa' a dam Y Wev claim as our invention':- a I 1-. 1n amethodofproducing a-gspray conepfg substantially unvarying; cone angle thesteps; of; el ver e I x Orifiqe a wi in mas 101 fluid to be sprayed} deriving: said fluidffrom a] supply of variable flow rate, at low fiowF rfl te introducing the fluid into said swirling. mass in a small stream ofisubstantial ly a pre d eterminedy velocity, and at higher flow rat e introducing the fluid into the swirlingmass in a larger stream at substantially said predetermined veloeity.

2 In a method of'prod'ucing a spray cone of substantially unvarying cone angle, the steps of delivering to a fixed orifl'cel' a swirling mass of fluid to be sprayed, deriving said fluidffrom a supply of variable flow rate, at 'low' flow rate introducing the fluid into said swirling mass in a small stream of substantially a'predetermined velocity, and at progressively higher flow rates introducing additional streams of fluid of proportionately greater volume but, at substantiallysaid predetermined velocity into said swirling mass in addition to said small stream. a I V Z 1 combination in a spray nozzle assembly of the character described, means defining a fixed spray orifice, means defining a swirl chamber of 'flxedsize immediately upstream from said orifice, fs'a'id swirl chamber having a plurality of spaced tangentially directed fluid delivery'ports opening"thereintofsaid ports being oia'r'espectively' different cross sectional new areas, and means for supplying to said respective 'vports fluid to be sprayed and of respective flow rates substantially proportioned to the sizes of the respective ports to pass through the ports into the swirl chamber at substantially constant velocity.

4. In combination ma spray nozzle construction for producing a spray stream of substantially conical shape and constant cone angle throughout a substantial range of flow rates of a supply streampf fluid, structure defining a plurality of fluid delivery passages and means'for controlling said passages including a control valve biased coaxial relatively movable and successively operable members responsive to supply stream fluid pressure over a preset value.

'5. In combination in aspray nozzle construction for producing-a spray stream of substanially conical shape and constant cone angle throughout a substantial rangeof flow ratesof a supply stream of fluid, structure defining a pluralityiof fluid delivery passages and-means for controlling saidpassages including acontrol valve mechanism comprising a pluralityv of spring biased coaxial relatively movable and successive- 1y. operable members responsive to, supply stream fluid pressure over a present value, said movable members having respective oppositely facing pressure responsive surfaces and having spring means biasing the m'embers to relatively separated positions, but yieldable under fluid pressurethrust against said respective surfaces for relative movement of the members toward one another.

6..In combination in a spray nozzle construction for producing a spray stream of substantially conical shape and constant "cone angle throughout a substantial range-of flow rates of a supply stream of fluid, structure defining a plurality of fluid delivery passages and means for controlling said passages including a control valve mechanism comprising a plurality of spring biased coaxial relatively movable and successively operable members responsive to supply stream fluid pressure over apreset value, and means for guiding said members for movement in the samedi-rection under the influence of said fluid pressure, said membersbeing operatively interengageable to move jointly in one phase of operation.

7. In combination in a spray nozzle construction of the character described, a nozzle plug 35. mechanism comprising a plurality of spring having a rearwardly opening cylinder for passage of fluid to be sprayed thereinto, a fluid sensitive control piston operable in said cylinder, a ring retainermounted at the mouth of said cylinder and partially overlapping said cy1in-- der mouth, spring biasing means normally driving said piston into sealing relation to said retainer, said retainer having fluid passage therethrough, and an auxiliary fluid sealing member normally biased into sealing relation to the retainer passage and responsive to pressure 'of the fluid supply over a preset value to be moved by the fluid to uncover the retainer passage.

8. In combination in a ,spray'nozzle of the character described, a nozzle frame tube, a nozzle plug in said tube, means at the forward end portion of the plug for effecting a spray stream, means in the rear portion of the plug for controlling fluid supply to said spray means, the plug having a plurality .of peripheral longitudinally extending independently isolated passages communicating from the rear portion of the plug with the forward end portion to supply fluid to said spray'means, the plug also having a fluid passage in the periphery thereof which opens freely to fluid supply rearwardly of the plug and communicates with the forward portion of the plug.

9. In combination in a spray nozzle construction, a tubular casing, a nozzle frame tube of substantial length and having spaced substantially rearwardly therefrom an externally threaded portion threadedly assembled within themouth of said tubular casing, a nozzle plug fitted in fluid-tight relation within the bore of the nozzle frame'tube, a cylindrical swirl chamber opening forwardly from said plug, an orifice plate closing the mouth of said swirl chambensaid plug having a series. of fluid delivery ports opening tangentially thereinto, said plug having fluid passages longitudinally therein communicating with said ports, the rear end of said plug communicating with the interior of said casing tube, and means carried by the plug controllingfluid flow through said passages.

, lOLIn combination in a fuel atomizing nozzle structureadapted for use in supplying atomized fuel into the combustion chamber of a turbo-jet aircraft engine, a tubular nozzle casing, a nozzle plug fitted in said casing and closing the forward end of the casing, said nozzle plug having a cylindrical swirl chamber recessed within the forward end thereof, means in said-plug for directing fuel into said swirl chamber, the outer end of the swirl chamber recess being defined by a plurality of steppedcounterbores, an orifice plate seated in the innermost of said counterbores, and a threaded-retaining ring threaded into the next adjacent outer counterbore and retaining the orifice plate assembled in its counterbore in closing relation to the swirl chamber.

11. In combination in a fuel atomizing nozzle structure adapted for use in supplying atomized fuel into the combustion chamber of a turbo-jet aircraft engine, a tubular nozzle casing, a nozzle plug fitted in said casing and closing the forward end of the casing, said nozzle plug having a cylindrical swirl chamber recessed within the forward end thereof, means in said plug for directing fuel into said swirl chamber, the outer end of the swirl chamber recess being defined by a plurality of stepped counterbores, an orifice plate seated in the innermost of said counterbores, and a threaded retaining ring threaded into the next adjacent outer counterbore and retaining taining ring having theiouter facethercof flush with the outer end of the plug and the outer end face of the plug and the outer face of the retaining ring affording a substantial radial area about the hollow portion of the ring, said hollow portion of the ring being of greater diameter than the-orifice portion of said plate and having a sharp ridge disposed closely adjacent to the perimeter occupied by a conical spray from the orifice to afford a carbon fence against 'accumulation of carbon about the orifice on. the

plate.

12. In combination in a conical spray atomizing nozzle, means defining a swirl chamber having an orifice concentrically arranged and a plurality of fluid delivery passages ported into said swirl chamber, and means in control of said passages comprising a bore having adjacent portions of different diameter and pressure responsive pistons respectively slidably operative in said bore portions, certain of said passages being controll-ed by one of said pistons and the other of said passages being controlled by the other of said pistons, said pistons being exposed to a source of fluid under pressure with the larger piston responsive to lower fluid pressure than the smaller piston by reason of the larger effective pressure area of the larger piston.

In combination in a fuel atomizing nozzle, means defining a swirl chamber havinga spray orifice therefrom and a plurality of fluid delivery ports leading thereinto, said fluid delivery ports having fluid passages communicating therewith and said passages communicating with abore having adjacent coaxial portions of different diameter, respective pistons of complementary diameter in said bore portions, said pistons being normally biased into separated positions by a common compression biasing spring, the oppositely facing faces of the pistons being exposed to a source of pressure fluid, certain of said passages being controlled by the larger of the pistons and others of the passages being controlled by the smaller of the pistons, the larger piston being shiftable by pressure fluid before the smaller of v the pistons for opening the passages controlled 14 l stantially constant while effecting said propor tioning of the volume of the fluid delivered.

15. In combination in a spray nozzle of the character described, a nozzle frame tube, a nozzle plug in said tube, means at the forward end portion of the plug for effecting a spray stream,

means in the rear portion of the plug for controlling fluid supply to said spray means, the plug having a plurality of peripheral longitudinally extending independently isolated passages communicating from the rear portion of the plug with the forward end portion to supply fluid to said spray means, the plug also having, a fluid passage in the periphery thereof which opens freely to'fluid supply rearwardly of the plug and communicates with the forward'portion of the plug, said fluid supply control means in the rear' portion of the plug comprising a chamber having a forwardly spring biased control piston movable rearwardly therein, said chamber having in its forward portion and-in front of said piston a port communicating. with said last-mentioned fluid passage and a plurality of ports inits rear portion controlled by the piston and leading respectively'to said plurality of passage.

16. Incombintaion in a spray nozzle of the character described, a'nozzle frame tube, a nozzle plug in said tube, means at the forward end portion of the plug for effecting a spray stream,

by the larger piston byreason 'of the'larger effective area exposed to the pressure fluid by the larger piston.

14. The method of producing a hollow conical atomized spray stream of substantially constant cone angle in the presence of a substantially varying fluid supply flow rate during operation,

which comprises delivering the fluid in the form of a vortex of substantially constant angularity to a fixed orifice from which the fluid is to be sprayed as aforesaid, proportioning the volume of the fluid delivered into the vortex in direct proportion to the fluid supply flow rate, and maintaining the velocity of said delivered fluid submeans in the rear portion of the plug for controlling fluid supply to said spray means, the plug having a plurality of peripheral longitudi- HAROLD GOLD. DAVID M. STRAIGHT.

REFERENCES CITED The following references are of record in the file of this patent;

UNITED STATES PATENTS Number Name Date 1,192,901 Irish Aug. 1, 1916 1,452,264 Binks Apr. 17, 1923 1,822,047 Leask Sept. 8, 1931 FOREIGN PATENTS Number Country Date Great Britain Aug. 23, 1934

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