US1722733A - Spray nozzle - Google Patents

Description

July 30, 1929.

B.YH. COFFEY ET AL SPRAY NOZZLE Filed Aug.' so. 1924 Patented i July 30, 1929.

UNITED srxrlifs1v PATENT ori-uca.

BARTON n. conny, ornmzannrn, NEW JERSEY, Nnvenonen s. naUrHINEnor Naw You, N. Y.,`AssIGNons 'ro man cooLnre Towna co. INC., or -Nnw Yonx,

N. Y., .L CORPORATION OF ll-'IEW YORK.

SPRAY NozzLE.

Application led August 30, 1924. Serial 110,735,117. l A

' Our invention relates to improvements in spray nozzles and particularly to-that class of nozzles useful in the art of cooling water by atmospheric action.'

Y 5 This type of nozzle is usually-located over ponds or roofs which receive the cooled sprayed water that'after bemg heated again passes through the nozzles and so on indelinitely. Vegetable growths and solid matter in the ponds or on the roofs get into the cir-r culation and clog the nozzles, constituting the v most serious trouble encountered in thexoperation ofthis type of cooling apparatus.'

, The chief object of this invention 1s to ,15' greatly minimize this trouble by wa large 1n! crease in the dimensions and area of the waterway through thenozzle for equal capacities and pressures Without decreasing ythe quality and cooling eiciencyof the spray- 20 cloud produced, compared with the Iexisting standards' of the contemporary art. L As a re sult of the novel features of our invention we. 'have increased the size of the water-way over the existing art known toI us, measured by minimum' dimensions, considerably over two hundred per cent and, measured by minimum A areas, over 4one hundred per cent, w1th 1 mprovement in the symmetry, texture and cooling eiiiciency of the spray-cloud.

A further object of the invention is to produce a novel and eiicient spray nozzle a furthcr object of'the invention. is to produce a spray nozzle which will discharge a high spray cloud in which the water particles are evenly and uniformly distributed; another l in which the danger of stoppage and clogging by foreign matter will be reduced to' a mm1- mum; a further object of the invention 1s to provide in a nozzle-a water passage of maximum diameter for a given capacity anda further object of the invention is to make a pracobject of the invention is to produce a nozzleV We accomplish these objects by the device Figure 2 is a side elevation with the vortex-` Figure 5 is a plan view of the device with the vortex chamber removed.

Similar characters of reference refer to similar .parts throughout the severaliviews.

Our improved nozzle includes a casing 1" in which we form a horizontal peripheral volute channel 2 an inlet passage,'means for producing a contracted jet of entering l, wate`r,

an equalizingvortex chamberll and la' discharge orifice 13.

The vertical spiral surface 3 of the horizontal spiral volute. channel 2 is preferably generated from the centers C1 and C2, symmetrical with thev axis 22. We do not limit ourselves tothe form of spiral herein described, however.

Beginning with the radius R1l and center- C2, the surface 3 of the spiral starts at thetangent point`20. 'The revolution of R1 is 90, ending at the vertical line V, through the axis 22, as indicated by thecirclel 25, on

which arrows' indicate` angular-- advance..

The-angular advance ofradius R2 is 180, that of R3 a little short of 90, ending at the point 21 where a very acute intersection'with the circle 1'7 takes place, practically a tangent.

It will be noted that point- 21is nearl on a` line AA, drawn through the center 1, normalto the'vertical through 22 and crossingl the tangent point 20.

The boundary of the volute channelv 2 is l the wall of the three sided rectangular gutter of decreasing vertical transverse section,

formed by the interior surfacesof the horizontal'4 parallel walls 18 and 19 and the vertical wall 3,`which begins at the tangentpoint 20, where it joins the wall 31 and ends at the tip of the lip 7 at about 315 angular advance. The wall 18, forming the top of the casing 1 is pierced b thecircular opening 10centered on the vertlcal axis 22 of the spiral, the circumference 17 of the aperture 10 hence forms the edge of the upper wall of the-volute channel 2, the lower wall or leg thereof being the surface 19 andthe channel itself is the space, measured vertically, between the walls v18 and 19, forming an elongated spiral wedge.

termination, a small intervening distance on its extended curve, shown in dotted line, to the point 21. If the functions of the volute channel did not continue in this distance, such would be immediately'reiected by an imperfection in the texture of the issuing The physical volute channel leaves, from its los spray cone at the orifice 13, which is extremely sensitive to any irregularitiesin the waterway or disturbances or interferences in the current. VWe attribute the vabsence of any suoli imperfections, irst,v tof the fact'` that in this region the residual water in the volute:

and that in the entering jet are moving in the same direction on parallel lines and at approximately the same velocity sothat interference,`if any, is negligible, and second, anyr space between the contracted jet and the volute stream would be kept flooded from l the sides and bottom by water under centrifugal pressure. As the volute begins to feed vthe vortex chamber on the -line..A-'A and tangent 20, it would seem desirable for uniform feed, that the tail end of the volute Vchannel should cease feeding on the same line and, from the appearance of the spray cone, that is what occurs. Any very small v irregularities in flow in this region would, however, be smoothed out in the vortex chainber before reaching, the orifice 13.

The inlet passage includes around secs tion 4 which merges into a rectangular sec.

tion 5.

The inner wall vGiof this inlet passage converges inwardlv with reference to wall 31, the

f convergencebein mainly in the'rectangular.

section 5, and ter inates in a sharp edge contraction lip 7 which projects into the waterway, at a still sharper angle, and forms a side wall of the substantially square orifice 8. vOn the casing .1 we provide a ca section 9 communicating with the casing 1 Iby a circular opening 10 and y.containing an equalizing Ivortex-.chamber 11," a throat 12 and a mouth 13. i I

Thei entrance port 14 ispreferably provided wit-li threads 141 by which the nozzle may be attached to a water main or other,

suitable source of supply.

The water enters the device at the entrance port 14 with parallel stream lines and on meeting the converging wall 6, the Istream lines adjacent thereto are forced to make an Aangle with the axis of Ithe entering water y and at the same time the velocity of the whole lmass is increased by reason of the decreased section of the water-way. At the sharp-edge l'contraction lip 7 the stream lines are further bent and make a still greater angle withv the .axis of the entering water.

At a point 15, beyond the oriice8 and adj acent to tangents and 21, there is produced in the water a jet of maximum contraction and maximum velocity in 'accordance with the hydraulic phenomenon of the vena contracta, indicated by the dotted curve 23.

As the volume passing the orifice 8 is equal to that passing the contracted )et section, the

velocities at these points are in inverse proportion to the corresponding areas and therefore the velocity at the contracted jet is I l I i insita-as greater than that at the orifice 8. The contracted (iet is `thus equivalent to `.that of a round e gc orifice of equal size having practically no contraction, without the serious disadvantage of forming a metallic barrier to the passage of solids through the nozzle. The minimum interior opening is orifice l8, larger than the contracted jet which produces the.

high velocity called for by the principles of this nozzle. The maximum contraction in the jet occurs at the tangent point 20 beyond the opening 8 where the jet enters the volute 2,

continuing onward in the volute under the 'stress of centrifugal force and encountering a gradually decreasing area,\the inner side of the jetl is uniformly exposed by the receding edge 17 of the volute. Under aheadvequal to the unbalanced centrifugal vpressure minus the static head from the edge 17 of the volute force, due to the horizontal component, keeps the {ilmin contact with the constraining surface until the particles leave the edge of the mouth 13 at angles of about 45 to the-v horizontal, in vertical planes tan ent to the -niouth 13. An infinite number ov such issuing streams of particles'produce a closely approximate cone with its apex at the mouth 13.

The spray cone is of very tine and uniform texture, height. y

As the volute channel 2 cannot be machined conveniently, casting roughness mars' the smoothness ofthe jet therein but these irregularities are smoothed out by the presperfectly symmetrical and of good sure of centrifugal force in the vortex cham ber, which is machined, and these irregularities are, therefore,"not'reected in the texture of the spray cone. v

Disturbance of the entering jet by contact with water'in the volute 2 is avoided by mak-` ing the vortex chamber 11 -tangental tothe volute channel 2 in close proximity tothe point of maximum contraction 20 of the jet.

The inner marginal ed e 17 of the top wall 18 of the spiral volute c annel 2is circular and concentric with the origin of the said channel, consequently, the area of the channel 2 constantly an uniformly diminishes, whereby the ribbon of water in the volute channel 2 constantly and uniformly overliows at every point the. marginal edge 17 of the channel and is practically exhausted at the tangent point-21, by reason of which the stream lines are not disturbed.

:"Ihe hole .16 in the bottom wall of l the chamavais-,me Lc l Iber19 performs a valuable function in freezing weather by draining` the nozzle, thus.

avoiding rupture from ice formation.

It'also prevents reduction of air pressure within the nozzle due to the exhausting action of the upward film flow and thus preserves full atmospheric pressure on the Water in the volute and on the film in. the vortex chamber 11 and throat 12.

In research experiments, we have ound the water ascends the walls of the vortex chamber 11 and ofthe throat 12 in a thin film, the result of high angular velocity and the accompanying high centrifugal pressure,

as in centrifugal separator practice. This feature of the invention produces Within the nozzle and, as is `Well understood, a water jet which continue along conical elements until whole nozzle, except the volute channel and inlet, practically air conditions and thus enables the sequence of hydraulic phenomena within the nozzle to function Without the disturbance, internal friction and interference losses that necessarily occur'within a flooded under water produces results Widely different from those of a'water jet in air.

By experiment, We iind thatthe area of the contracted jet and its orifice 8 are governing factors in varying the capacity and that the throat 12 is secondary in this respect. In practice, we make the throat 12 about equal to the horizontal dimension of the oriiice 8.

y The discharge at the mouth 13 is perfectly l the cylinder immediately expands into a. hollow cone under the stress of the horizontal and Vertical components and, as the expan-l sion continues, the lilin becomes thinner until at a horizontal plane of about one foot above the nozzle mouth, under usual operative conditions of pressure, surface tension fails and the cone rim dismtegrates into fine drops gravity exhausts the vertical component.

Having thus described our invention, what We claim is:-

l. In an air filled, film flow, free discharge, centrifugal spray nozzle, the combination of a volute channel, an inlet .passage tangental theretoand having a side Wall, a rectangular orifice therebetween, the side wall of said inlet passage terminating in a lip which makes a sharp angle with the remaining portion of said side wall and which extends in a 4 direction toward the axis of said passage wherebyv acontracted jet is produced in the volutechannel beyond the orilice.

orifice therefor above the vortex chamber, a.

volutechannel below tlievorteix and .open thereto, a tangental inletpassage to the;

volute channel ,merging into rectangular ormpthe side wall ofthe said inlet passage terminating in a lip having a sharp edge and which makes a sharp angleI with the remainn i'n portion of said sidewall and extends in a irection toward the'axis of saidA inlet passage vand-forms a contracted-orifice adapted to produce a contracted jet in the volute chan-v nel beyondjthe orifice.

3. In an air filled, uniformfilm flow, free discharge, centrifugal spray nozzle, the-combinationof achannel, a gradually diminishing top wall thereon, an inlet passage positioned tangentallyl to vsaid channel, aside Wall of said inlet passage terminatin in a lip which makes a sharp angle with te remaining portion of said side wall and which extends in a direction toward the axis of said passage,- forming a contracted section, a sharp edge on said lip adapted to produce a contracted jet beyondsaid inlet, a vortex chamberA above the top Wall of the channel and a circular opening between the vortex chamber and the channel. l

4. In an yair iilled, uniform ilm How, free discharge, centrifugal spray nozzle, the combination of a casing, a horizontal peripheral volute channel therein, an inlet passage positioned tangentially to the channeland hav-.-

ing a round section merging into a rectangular section, a side Wall of the rectangular section converging at a sharp angle toward the other side wall thereof and having a sharp edge to form a contracted orifice, a cap section on the said casing and communicating therewith by a circular opening, a vortex chamber in said cap section and a discharge port above the vortex chamber.

5. Inv a spray nozzle, the combination of an inlet passage, an open side volute channel connected with the inlet passage, said inlet passage being tangental to saidvolute channel, a side wall of said inlet passage terminating in a sharp edge contraction' lip which makes a sharp anglewith the remaining portion of the said side wall and which extends in a direction toward the axis of said passage and is adapted to produce a contracted jet in the channel, and a discharge orifice from the channel.

6. In a spray nozzle, the combination of an inlet, an open side spiral volute channelopening into said inlet, said inlet being tangentalto said volute channel, a side .wall of said inlet forming a sharp edge contraction lip adjacentxthe entrance to the said channel and adapted to produce a contracted jet therein, and a discharge orifice from the channel.

7. In a spray nozzle, the combination of an inlet, a spiral volute channel openingl Jfrom the inlet, said inlet being tangental to said volute channel, a side Wall of said inlet ter-v minatin'g in -a lip having a sharp edge and l adapted/to form aA contracte chamber.

d etbeyend theA the said 1ip,;a vortex chamberconnected with 10 lip, a vortex chamber openin roinihe c han-V vthe said channel and a 'dischargeoriice opennel and a discharge orifice ro' the vortex ing from the vortex,chamber.V c

j f n 1 y In testimony whereof, we have signed our 5 8. In a spray nozzle, the combination of a` names' 4to this specification, this 2 9- day of tangential converging inlet adapted tadmit August, 1924. a stream of Water, a sharpI edge contraction L lip in the path ofthe enterin stream, avolute BARTON'H. COFFEY, vchannel adapted to receive t e stream beyond GEORGE S. DAUPHINEE.

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