US2218110A - Spraying nozzle - Google Patents

Description

H. W. HOSMER ET AL SPRAYING NOZZLE Filed March 15, 1938 Patented-Oct. 15,1940

spasms NOZZLE Harrison W. Bosmer, Stoncham, and Earl Staiford, North Arthur D. Little, Inc

Mass, assignors to orporated, Cambridge,

Mass a corporation of Massachusetts Application March 15, 1938, sci-n1 No. 196,01ii 1 Claim. (01. 299-114) This invention relates to an improved nozzle foruse in the spraying and dispersing of liquids. The nozzle of this invention is of the spin or whirl chamber type wherein the spin or rotative 5 motion of the fluid in the chamber before entering the discharge orifice is eflected by tangential entry of the fluid into the spin chamber.

Objects and advantages of this invention include a more effective utilization of the energy of the fluid due to the pressure at which it is supplied to the nozzle, and the simplification of design, installation, maintenance and use, in comparison with nozzles now available. In conventional nozzles of the spin chamberclass, the spin is ordinarily imparted in one or the other of two ways. One way is by the use of spiral vanes within the nozzle in the path of the fluid; these vanes are essentially coaxial (with the spin 7 chamber and the discharge'port, and serve .to impart spin to the fluid. The'other way is by the conduction of the fluid through a side entry port in a tangential direction with respect to the axis of the spin chamber of the nozzle, thereby imparting spin or rotative motion to the fluid in the spinzchambe'r. The present invention constitutes an improvement upon nozzles of the latter, or tangential-entry, class.

Nozzles of this latter class are further subdivided into two types, as to their general design with respect tothe fluid passages leading to the spin chamber from the supply chamber,- which may be a reservoir, supply pipe, or other means for conducting fluid to the nozzle as- I sembly.

Inone of these two types, which is illustrated in United States Patent No. 1,361,238 01. R. S.

Fleming, the direction of flow of the fluid entering the nozzle assembly is substantially parallel to and usually coincident with the axis .of the w spin chamber and the body of the spray; In

order to secure a tangential entry into the spin chamber portion of the nozzle, therefore, the direction of fluid must be changed by passages :within the nozzle, through at least 90 or thereabouts. This results in passages which are par- J ticularly susceptible to clogging, and also generally requires complete disassembly of the nozzle for cleaning. For practical purposes, nozzles of this type must be made in at least two pieces, and usually require complete machining of all portions coming in-contact with the fluid.

. This type of nozzle is more commonly used where only a single nozzle is mounted on the supply pipe and where the coaxial position of so the supply pipe, nozzle body, and spray oiler structural and design advantages, as for instance in oil burners and spray dryers in which it is desirable to supply an air stream annularly and symmetrically to the mass of spray.

In the othertype, sometimes referred to as 5 the side entrance type, the initial flow in the connection to the supply pipe is in the same general direction as in the tangential entry port itself. This type is frequently'called non-clogging on account of the more direct and larger 10 passages leading to the tangential ports of the spin chamber.v As a rule, this passage is of much greater length and cross sectional area than that of the entry port to the spin chamber,

to provide physical strength and a suflicient 15 thread length for the usual pipe thread method -of attachment. Nozzles of this type are frequently used in multiple in spray chamber or "spray pond installations in which-a number of of the fluid must be changed substantially.

nozzles are mounted on a single supply pipe, or go manifold,'the direct connection being either to the side outlet of-Ts or to threaded nipples welded to the supply pipe at intervals. In either case it will be noted that the direction of flow 26 Nozzles made in accordance with the present invention do not employ the vanes, side fittings, or complex internal passages which are characteristic of the spin' chamber nozzles now commonly used. The fluid moves directly from the so supply chamber into the spin chamber through tangential openings in the body of the nozzle, and the spin of he fluid is imparted by the combined efiects of e motion or energy of the fluid and the location of the openings with respect to 35 the spin chamber. These improved nozzles. arev therefore simple in design and easily constructed, as will be further pointed out hereinafter. They. also result in a saving of space, and may be readily installed and removed. They arealso particularly advantageous in that they reduce toa minimum the friction losses in spraying. In conventional spin-chamber nozzles wherein spin is imparted by tangential entry of the fluid into .the spin chamber, the fluid has its direction changed in passing from the supply chamber into the spin chamber, since it must, in so passing, move through side fittings or through internal passages within the nozzle body. The

present invention, by elimination of side fittings drawing,

Figure 1 represents a side view of one form of the complete nozzle, in operating position;

Figure 2 represents an end view of the cap portion of the nozzle of Figure 1;

Figure 3 represents a sectional view of the cap portion of the nozzle of Figure 1 in the plane of the axis of the nozzle;

Figure 4 represents a sectional view of the tip portion of the nozzle of Figure 1, in the plane of the axis of the nozzle;

Figure 5 represents an end view of the tip portion of the nozzle of Figure 1; and

Figure 6 represents a sectional view of a modifled form of the nozzle, in the plane of the axis of the nozzle.

Like figures refer to like parts throughout the drawing.

Referring now to the drawing, and more particularly to Figures 1 to 5 inclusive, I represents the cap portion of the nozzle and II the tip portion. The cap I0 is threaded over a portion of its outer surface, as shown at H, and this thread- L ed portion of cap l0 screws into the tip II which is correspondingly threaded on its interior sur- The threaded portion ll of cap I0 is preferably of lesser diameter than the rest of the cap, thus providing a shoulder l adapted to abut firmly against the end surface 2| of tip II when the cap and the tip are tightly screwed together. One or more tangential holes or entrance ports I! are provided in the unthreaded portion of cap 10; these ports extend from the exterior of cap' III to the interior surface l3, and their axes are substantially tangential to the interior surface ll which surface is of cylindrical shape, and defines the upper portion of the spin chamber. Both the interior surface If and the exterior surface ll of tip I I are threaded. The threadings of the interior surface It are adapted to receive the threaded portion of the cap III; while the outer surface I! is threaded in order that the assembled nozzle may be screwed into and through the walls of the supply chamber. As shown in Figure 1, one wall of the supply chamber is indicated by the numeral 23, and the fluid in the supply chamber is represented by the numeral 24. The tip H is provided at its bottom end with a restricted circular orifice l8, which is coaxial with the spin chamber. The approaches to the orifice may be tapered as indicated at I! and 22. The angle of taper is conveniently about 120, although this is not critical. The edges of the bottom are conveniently hexagonal or square, to facilitate screwing the nozzle into its position in the wall of the supply chamber. I

. For installation, the nozzle is first assembled by screwing the cap l0 tightly into the tip I l. The nozzle is then screwed firmly into an opening through a wall 23 of the supply chamber, which opening is of course threaded to fit the threads on surface H. The nozzle should be screwed in far enough so that the port or ports It will be entirely within .the inner surface 28 of the wall of the supply chamber. How much further the nozzleis screwed in (up to the point where the base contacts the outer surface 21 of the wall 23) is not important, so long as there is no leakage of 1 fluid past the threads, except that the nozzle should not be screwed in so far as to impede fiow or circulation of fluid 24. For example, when the fluid 24 is fiowing through a pipe of relatively small diameter, the presence of a number of nozzles projecting their maximum distance into the pipe would tend to impede the flow of the fluid.

The nozzle may be readily removed for clean- .ing, replacement, or .repair by merely unscrewing it, preferably after first removing the fiuid, or at least the pressure, from the supply chamber.

After the nozzle is placed in position as above described, the fluid 24, under sufficient pressure to cause it tofiow outwardly from the supply chamber through any orifice therein, passes into the tangential port or ports i2, thereby establishing a whirling motion within the spin chamber, which chamber is defined essentially by the interior walls It and IS. The fluid moves outwardly toward and through orifice l8, and emerges therefrom as a hollow conical sheet which quickly breaks up into droplets of spray.

The number of nozzles used forany installation depends of course upon such matters as vol- 'ume of spray desired, size of nozzle, capacity of the equipment, etc. If it is desired to provide a means for spraying a considerable quantity of fiuid over a given surface or object, for example, it may be convenient to arrange pipes running from a suitable supply and pressure source containing the fiuid, and providing each pipe with a sufiicient number of nozzles for the purposes and conditions involved. The nozzles may be posi-,

tioned to spray downwardly, upwardly, or at any suitable angle between.

The nozzle of this invention has been shown and described as being made in two parts,--the cap [0 and the tip II, as that appears to be the most convenient configuration in which to make it. It would of course be possible to make the nozzle in more parts, or in only one piece, to give functionally the same final form. However, there appears to be no particular advantage, and considerabledifilculty or at least extra effort, in such other ways; and inasmuch as the nozzle of this invention is designed for simplicity, one of the simplest forms of it has been described herein. Minor modifications may readily be made,--for example, instead of forming cap ill with a top portion of enlarged diameter, whereby shoulder l5 abuts edge 2| of tip II when the parts-are screwed together, the tip H may be made with enlarged internal diameter for the threaded portion, whereby the bottom of cap in abuts the shoulder of the unthreaded interior portion of tip H. In this way, a spin chamber of the same diameter throughout its length can be provided.

Another alternative form is shown in Figure 6, wherein the numbering is essentially the same as in Figures 1 to 5 except that each number is preceded by the numeral 1. In this form, the, cap portion H0 may be made to include the entire nozzle except for a tip III which includes merely the orifice Ill and the bottom end of the spin chamber; which tip would be screwed or otherwise placed into position in the bottom of the cap. Inasmuch as the threaded portion of surface Ill would then be part of the cap, the outer portion I20 of the base should preferably also be part of the cap, so that the two would cooperate when the nozzle is inserted into or removed from the wall of the supply chamber.

While the foregoing disclosure sets forth in de- 7:

threaded exteriorly throughout a part of its length and screwing into the tip portion, the unthreaded part of the capportion being of greater diameter than the threadedpart thereof but of lesser diameter than the extericrly threaded part of the tip portion, said nozzle being adapted to screw into a threaded opening in the wall of said supply chamber by means of the exterior threads on the tip portion, the positioned nozzle extending into the supply chamber a distance less than the diameter of the cap portion, the joined cap and tip portions defining a spin chamber, said chamber having inlet ports in the unthreacled part of the cap portion, said ports being tangentially disposed to the axis of said spin chamber and positioned to provide straight-line communication from the supply chamber to the spin chamher and to impart spin to the fluid being sprayed, and an outlet spray-orifice positioned coaxialiy with said spin chamber and in the tip portion at the end opposite the cap portion, said inlet ports having an aggregate cross-sectional area not appreciably in excess of that of the outlet orifice.

-said nozzle being capable of forming a spray by,

virtue of the fluid pressure in .the supply chamber; said wall of the supply chamber extending outwardly for a considerable distance away from the line of contact with the nozzle and thus per- 1 mitting unimpeded flow of'the fluid in substantially a straight line, from points relatively remote'in the body of said fluid in'said supply chamber, through each inlet port into said spin chamber.

HARRISON W. HOSMER. EARL STAFFORD.

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