US2745701A - Spray nozzle orifice approach - Google Patents

Description

May 15, 1956 F. w. WAHLIN 2,745,701

SPRAY NOZZLE ORIFICE APPROACH Filed Aug. 5, 1952 i 27 2'" Z .Z 1574/ 2 4? 30 15a 15 -l 15 14/ 1 f6 29 2a IN VEN TOR.

gag; w Wdhzz United States Patent Q SPRAY NOZZLE OR-IFI'CE- APPnoAcrr Fred W. Wahlin, Oak Park, 11]., assignor to Spraying Systems Co.,. Bellwood, III., a corporation oli'lliinois Application AugustS, 1952, Serial No. 3 02,681

4 Claims. (CL 299-153) My invention has reference. to spray nozzles, especially of the flat fan shape spray type, and has reference more particularly to facilities for controlling the final flow of the liquid to the nozzle orifice.

Such nozzles have a liquid supply passageway therein which leads to the orifice, and it is customary to reduce the orifice end portion of this passageway to a relatively small size to provide an orifice approach of appreciable length through which the liquid flows directly to the orifice at an accelerated rate.

This approach portion of reduced size usually terminates in a somewhat rounded or dome'shaped' outer end, and the orifice, which is of narrow, elongated slit like shape, extends across this rounded or dome shaped end and by reason thereof has an arcuate contour corresponding thereto which contributes fanwise spread to the spray.

In some spraying operations, especially with small capacity spray nozzles, it has been found that the lateral edge portions of the fan shape spray are thinned out so that they do not have adequate volume at those places for uniform spray coverage. pecially in spraying liquids, such as paint, which are of higher viscosity than water, such small capacity spray nozzles do not give as complete break up of the spray as desired.

The principal objects of my invention are to improve the break up of the spray produced by such nozzles; to give greater uniformity of spray distribution fanwise of the spray stream; to provide simple facilities which are readily applicable to spray nozzles to improve the operation thereof; and to provide a convenient method of incorporating such facilities in the nozzle; these and other objects being accomplished as pointed out hereinafter and as shown in the accompanying drawing, in which:

Fig. 1 is a view looking directly at the discharge end of a spray nozzle made in accordance with the present invention;

Fig. 2 is a sectional view of the nozzle of Fig. 1 taken on theline 22 thereof;

Fig. 3 is an enlarged fragmentary view of a portion of the nozzle tip shown in Fig. 2;

Fig. 4 is an enlarged sectional view of a fragmentary portion of the nozzle tip taken on the line 44 of Fig. 1, but omitting the restriction, which is shown in Fig. 3, of the entrance to the terminal or discharge end portion of the nozzle passageway;

Fig. 5 is a cross sectional view of the nozzle tip taken on the line 5-5 of Fig. 3;

Fig. 6 is a fragmentary cross sectional view of the nozzle tip taken on the line 66 of Fig. 3; and

Fig. 7 is a sectional view, greatly enlarged, of a fragmentary portion of the nozzle tip in the course of construction thereof, and showing facilities for producing the restriction, shown in Figs. 3 and 6, of the entrance to the terminal or discharge end portion of the nozzle passageway.

Figure 8 is a plan view of the spray pattern of a spray nozzle made in accordance with the present invention in Also in some cases, es-

solid lines and the spray pattern of a conventional fan shaped spray nozzle in dotted lines.

Referring to the drawing, I have for the purpose of illustration, shown a nozzle like that of my application Serial No. 81,288, filed March 14, 1949, now Patent No. 2,621,078 and composed of abody 10 having a largecylindrical opening 11 therethrough, a fiat sidednozzle tip 12 which is made as a separate part and secured to the outer end of thebody 10, astrainer 13 in the cylindrical opening 11' of the body and having an annular flange 14 at the outer end thereof interposed between thenozzle tip 12 and the outer end of the body it), and aclamping member 15 by which the nozzle tip 12' is secured to the body 119.

Thebody 10 is internally threaded at 16 at its end remote from thetip 12 for connection to a pipe or other means through which liquid is supplied to the nozzle and the other end of the body is externally threaded at 17' for threaded connection therewith of theclamping member 1'5 which is of collar nut type with the outer end of the collar turned in as at 15a to engage over anannular flange 18 at the base of the nozzle tip for clamping the latter against the outer end of the strainer 13' and the strainer flange 14 against the outer end of the nozzle body. Theclamping member 15 andbody 10 each have a portion of the length thereof of external hexagonal form as indicated at 19 and 20 respectively, or of other suitable form for wrench engagement for conveniently securing the parts together.

The, illustratedstrainer 13 has a hollowcylindrical body 21 surrounded by acylindrical screen 22 which is secured thereon by ascrew 23 which is threaded into the lower end of thestrainer body 21 and has a large head against which the lower end of thescreen 22 abuts. Thestrainer body 21 has a series oftransverse slots 24 through its Wall, preferably at several places therearound, for exmple at diametrically opposed sides thereof, so that the liquid introduced through the lower end of the nozzle passes through the screen into the interior of thestrainer body 21. Thebody 21 is preferably turned down, at the slots and a short distance at each side of each slot, to a size smaller than the interior of thescreen 22 and preferably with annular screen contacting ribs 25 left at suitable intervals, so as to allow free flow of liquid through a considerable area of the screen to theslots 24.

Thenozzle tip 12 has a large bored out cavity orcounterbore 26 communicating with the interior of thestrainer body 21 and leading to a relatively small diameter bore orcylindrical passage 27 with convex or dome shapedouter end 23 through which thespray orifice 29 is formed.

Theorifice 29 is preferably recessed in the end of the nozzle at the bottom of a channel orgroove 30 which extends in a direction across the nozzle end, and at its bottom, thisgroove 30 is provided with asmall groove 31 usually of V-shape as shown, which cuts through and intersects the dome shapedouter end 28 of the bore orpassage 27 to form theorifice opening 29 which is of long narrow shape and of an arcuate contour from end to end corresponding to therounded end 28 of thebore 27 at the place where the orifice extends thereacross.

Thus the nozzle body opening 11, the relatively largenozzle tip cavity 26, and the small diameter bore 27, conjointly provide a passageway through which liquid is supplied to theorifice 29, and because of the small diameter of thebore 27, the liquid flows therethroug'h to theorifice 29 at a highly accelerated rate.

Generally thebore 27 is made with an abrupt shoulder around the entrance, substantially as shown at 32 in Figs. 4 and 7, and is of considerable length relative to the diameter thereof to insure a long straight path of accelerated how of liquid before it reaches the orifice 29'.

of thebore 27 so that the orifice is substantially closer to thebore entrance 32 than heretofore, better break up of the spray liquid occurs and also greater uniformity of spray distribution, especially at the lateral edge portions of the fan shaped spray stream.

I have found further that the spray distribution and break up of the spray liquid is further improved by locally restricting the entrance to the bore, as for example by providing the bore entrance with an internal annular rib orbead 33 therearound which is preferably of V-shape as shown.

Tests have shown that with an abrupt shoulder, such as indicated at 32, a sharp reduction of peripheral pressure around the stream of liquid occurs in thebore 27 immediately beyond the entrance thereto, and that beyond this place of sharp reduction in pressure there is a progressive increase in the peripheral pressure and the general shape of the stream flow in thebore 27 is approximately as indicated by dotted lines at 34.

Thus there is an initial contraction of the size of the stream immediately beyond the entrance to thebore 27 and then a progressive expansion or spreading of the stream to the bore size which appears to contribute better break up to the spray and greater uniformity of spray distribution, especially at the lateral edge portions of the fan shaped spray, if theorifice 29 is located sufficiently close to thebore entrance 32 to be approximately at the place of full expansion of the stream to the bore size.

Generally it has been found that a nozzle construction in which the length of thebore 27 is approximately one to one and one half times the diameter of thebore 27 the most satisfactory conditions of break up of spray and uniformity of spray distribution are obtained. Approximately this relation of bore length to bore diameter is shown in Fig. 4 of my copending application Serial No. 82,251, filed March 18, 1949, now Patent No. 2,618,- 511, and the present application is a continuation in part of said application Serial No. 82,251 in that respect.

With this relation of bore length to the diameter thereof, theorifice 29 is located at a place where the stream of liquid is under a cross sectional expanding influence which not only tends to facilitate separation into spray particles but also gives greater impetus to the flow of liquid laterally through the opposite end portions of theorifice 29.

Local restriction of the entrance to thebore 27 by the provision of an internal annular rib orhead 33 therearound provides greater reduction of pressure around the stream of liquid immediately beyond the bore entrance and more pronounced cross sectional expansion of the stream therebeyond, as indicated by the dotted lines at 35 in Fig. 3, and with the bore length approximately one to one and one half times the diameter of the bore, and corresponding proximity of theorifice 29 to the locally restrictedentrance 33 to thebore 27, a better break up of spray occurs and greater uniformity of spray distribution occurs, especially along the edge portions of the fan shaped spray, than with thebore entrance 32 of Fig. 4.

Generally in fan shaped spray nozzles the lateral edge portions of the fan shaped spray have a diminished or disproportionate volume, somewhat as indicated by the dotted lines at 36 in Fig. 8, whereas the shortening of thebore 27 as above explained gives greater fullness of spray at the edge portions of the fan shaped spray as indicated by the full lines in Fig. 8.

Any convenient means may be employed for locally restricting the entrance to thebore 27, but I prefer to peen in the peripheral edge of the bore entrance to form the rib or bead 33 therearound. Y

This may be conveniently accomplished, as indicated in Fig. 7, by employing aball 37 of a diameter somewhat greater than that of thebore 27 and pressing this ball, in the direction of the axis of thebore 27, against 4 theperipheral entrance shoulder 32 of thebore 27 with sufiicient force to deform the metal around the bore entrance and thereby form the rib orhead 33. In this operation the metal around the end of the bore or passage 27' is locally swaged and compressed and deformed to produce the rib orbead 33.

For performing this rib or bead forming operation a conventional press may be employed having a bed plate or support 38 on which the nozzle tip is placed and aplunger 39 which is reciprocable toward the bed plate or support and holds theball 37 in a manner'to be projected downwardly into thecavity 26 of the nozzle tip.

It is important that the rib orbead 33 be concentric with thebore 27 and uniform therearound, and to insure exact centering of theball 37 with the entrance to thebore 27, theball 37 is preferably'loosely supported on the plunger directly under thepressure face 40 thereof, by a series of claw likefingers 41 which are secured to the lower end of theplunger 39 at suitable intervals therearound and have inturnedlower ends 42 which loosely embrace the ball at sutficient distance below the center thereof to retain the ball on the end of theplunger 39.

Thus the ball is free to rotate and has sufficient freedom of lateral movement so that when projected downwardly against the entrance to the bore it is accurately centered therewith and concentricity and uniformity of the rib orbead 33 produced thereby is assured.

While I have shown and described by invention in a preferred form, I am aware that various changes and modifications may be made therein without departing from the principles of the invention, the scope of which is to be determined by the appended claims.

What I claim is:

l. A spray nozzle of the class described comprising a one-piece body having therein a,cylindrical passage which has an entrance end and an exit end and extends part way through the one-piece nozzle body to a passage end closing portion of the one-piece nozzle body, the

'said passage having at the exit end thereof a spray discharge orifice communicating through said passage endclosing portion to the exterior of the nozzle, and the said passage having at its entrance end a deformed portion of the one-piece body providing an internal annular bead surrounding and restricting the entrance of the passage.

2. A spray nozzle of the class described comprising a one-piece body having therein a cylindrical passage which has an entrance end and an exit end and extends part way through the one-piece nozzle body to a passage end closing portion of the one-piece nozzle body, the said passage having at the exit end thereof a spray discharge orifice communicating through said passage end closing portion to the exterior of the nozzle, and the said passage being surrounded at its entrance end by a locally swaged and compressed portion of the one-piece body which forms an internal annular head at said entrance end of the passage.

3. A spray nozzle of the class described comprising a one-piece body having therein a cylindrical passage which has an entrance end and an exit end and extends part way through the one-piece nozzle body to a passage end closing portion of the one-piece 'body, the said passage having at the exit end thereof an elongated spray discharge orifice extending crosswise of said passage and communicating through said passage end closing portion to the exterior of the nozzle, and the said passage having at its entrance end an annular deformed portion of the one-piece body protruding toward the axis of the passage and providing a V-shaped internal annular bead around the passage at the entrance end thereof.

4. A spray nozzle of the class described comprising a one-piece body having therein a cylindrical passage with a counterbore at one end, said passage having an entrance at the counterbore end and an exit at the other end and the said passage extending part way through the onepiece body to a passage end closing portion of the onepiece nozzle body, the said passage having at the exit end thereof a spray discharge orifice communicating through said passage end closing p0: lion to the exterior of the nozzle, and the said passage having at its entrance end a deformed portion of the one-piece body providing an internal annular bead surrounding and restricting the entrance of the passage.

References Cited in the file of this patent UNITED STATES PATENTS 456,538 Potter July 21, 1891 6 Martin June 26, 1906 Olsen Nov. 7, 1922 Brewer Jan. 4, 1927 Murray Apr. 8, 1930 Freeman July 7, 1931 Anderson May 8, 1934 Faast June 26, 1934 Squires July 10, 1934 Holveck Aug. 2, 1938 Peeps Apr. 5, 1949 Fuller June 15, 1954

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