Title:
Spray nozzle
United States Patent 2161111


Abstract:
Our present invention relates in general to the construction and operation of liquid spray nozzles, and more particularly to spray nozzles capable of producing a relatively flat spray over an extensive spray area. One of the main objects of the invention is the provision of a spray nozzle...



Inventors:
Wilcoxson, Leslie S.
Ely, Frederic G.
Application Number:
US2340635A
Publication Date:
06/06/1939
Filing Date:
05/25/1935
Assignee:
BABCOCK & WILCOX CO
Primary Class:
Other Classes:
110/238, 239/263.2, 239/521, 423/207, 423/DIG.3, D32/32
International Classes:
B05B1/26; B05B3/14; F23G7/04
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Description:

Our present invention relates in general to the construction and operation of liquid spray nozzles, and more particularly to spray nozzles capable of producing a relatively flat spray over an extensive spray area.

One of the main objects of the invention is the provision of a spray nozzle of the type described which is further characterized by its extremely simple construction, the ease and low cost of construction of the nozzle and renewal of its wearable parts, and its effective provisions for confining the spray discharged to a predetermined spray area. A further object of the invention is the provision of a simple and effective form of nozzle mount and operating mechanism therefor arranged to effect a plurality of independently regulable oscillating movements of a spray nozzle, especially one of the type of our improved spray nozzle.

The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which we have illustrated and described preferred embodiments of our invention.

Of the drawings: Fig. 1 is a sectional elevation of a spray nozzle constructed in accordance with our invention; Figs. 2 and 3 are plan and end views respectively of the spray nozzle shown in Fig. 1; Fig 4 is a sectional elevation of a chemical recovery furnace in which our improved spray nozzle is especially adapted for use; Fig. 5 is a horizontal section taken on the line 5-5 of Fig. 4; Fig. 6 is an enlarged view of the spray nozzle mount shown in Fig. 4; Figs. 7 and 8 are plan and end views respectively of the nozzle mount shown in Fig. 6; Fig. 9 is a somewhat diagrammatic elevation of one form of spray nozzle oscillating mechanism; Fig. 10 is a side view of the crank disc shown in Fig. 9; and Fig. 11 is an elevation of a modified form of nozzle mount and oscillating mechanism.

As shown in Figs. 1-3 particularly, our improved spray nozzle is formed with a nipple I threaded at its upper end for connection to a liquor supply pipe and connected at its lower end to a discharge pipe formed by a tubular plug member 2. The plug 2 is formed with a discharge passage 3 having its upper end tapering from the nipple passage downwardly and its lower end of uniform circular flow area and located in a central projecting nozzle portion 4 of the plug. The spray nozzle also includes a spreader plate 5 in the path of discharge of the passage 3, and spaced from the lower end of the nozzle 4. The spreader plate 5 has a flat upper surface 6 arranged at a predetermined angle A to the axis of the discharge passage 3 to receive the impact of the liquid discharged and cause it to be distributed over an extended angular area in a relatively flat thin stream. The angle A will be varied in accordance with the desired angular distribution of the spray. As shown in Fig. 2 the spreader plate is of approximately elliptical form when the end of the discharge passage is of circular crosssection.

With the discharge passage and spreader plate formed and arranged as described, the stream of liquid will impact on the upper face of the spreader plate over a substantially elliptical area, and be distributed over the plate in predetermined proportions. We have found for example, that with the liquor at a suitable viscosity and pressure and an angle A of approximately 48° to 25 500, as shown, a major portion of the liquor would flow over the spreader plate within an angular area of about 600 about the longitudinal axis of the spreader plate, while the remaining portion of the liquor would be distributed over the remaining 3000, progressively decreasing in amount with increases in the angular distance from the main flow area. Our improved nozzle shown is especially designed for delivering a flat spray over an angular area of approximately 180°. For this purpose the spray nozzle is formed with a tubular hood 7 surrounding the body of the plug 2 and extending downwardly beyond the end of the nozzle 4. The lower end of the hood terminates in t o oppositely extending intersecting 40 planes 8 and 9 intersecting along a transverse line in alignment with the lower side of the discharge passage 3. The side 8 contacts with and is welded to the upper surface of the spreader plate 5.

With this arrangement of the hood any portion of the liquid discharged impinging on the spreader plate and deflected toward the rear thereof will enter the annular space between the plug nozzle 4 and the hood 7, and rapidly return or be thrown back on to the spreader plate. in the general direction of flow thereon. The described arrangement of the side 9 of the hood insures that the spray will be confined to an angular area of approximately 180*, The spray nozzle described is especially designed for use in a recovery process and furnace of the character described and claimed in a pending application of George H. Tomlinson and Leslie S. Wilcoxson, Serial No. 21,836, filed May 16, 1935, for delivering to the furnace waste liquor containing inorganic chemicals and combustible organic matter, such as the residual liquor from pulp digestors in the sulphate and soda processes of manufacturing paper pulp. Such a recovery -furnace is illustrated in Figs. 4 and 5 and, as shown, a spray nozzle 10 of the character described is positioned adjacent to the front wall 15 of the furnace and arranged to discharge a relatively flat spray across substantially the entire horizontal cross-section of the furnace against the rear wall 16 and side walls 17 and 18 which act as arresting surfaces receiving the impact of the sprayed particles.

The spray nozzle 10 is advantageously mounted so as to permit continuous predetermined oscillating movements thereof to vary the area of impact of the spray particles on the rear and side walls. A suitable mount for this purpose is illustrated in Figs. 6 to 8, and includes a horizontally arranged liquor supply pipe 20, extending through a vertically elongated port in the front furnace wall 15, and on the inner end of which the spray nozzle 10 is mounted at an angle to the pipe. The pipe 20 is rotatably mounted at its outer end in a sleeve 21 carried by a plate or table 22 pivotally mounted for movements about a transverse horizontal axis by means of a pivot pin 23 at its inner end journaled in lugs 24 carried by adjacent furnace wall tubes. The outer end of the pipe 20 is connected to a flexible black liquor supply connection 25. With this form of mount, the spray nozzle can be oscillated in a vertical plane about the axis of the pivot pin 23 and also about the axis of the pipe 20.

With the pipe 20 horizontal and the spreader plate 5 also in a horizontal position, the spray would impact on the side walls 17 and 18 along similar areas increasing in size and curving downwardly towards the rear wall 16, and on the rear wall along a rectangular area corresponding to Sthe limits of the area of impact at the rear end of the side walls due to the longer distance the spray particles must travel to reach the rear wall in a furnace of the oblong cross-section illustrated.

Most of the spray discharged is concentrated in a relatively small height, with a minimum of generally finer particles traveling at the upper and lower sides thereof. If the spray nozzle were continuously maintained in this horizontal position the impact of the spray particles on the rear and side walls along a relatively restricted area would limit the amount of material that could be treated in a furnace of the proportions illustrated without the material flowing down the walls in an excessively wet condition.

To provide a more extended area of deposit on the side and rear walls while maintaining the desirable flat coarse spray and rendering the material as deposited more exposed to the furnace temperature conditions, mechanism is provided for continuously oscillating the spray nozzle vertically and about the axis of the pipe 20.

As shown in Figs. 6 to 8, the outer end of the pipe 20 has secured thereon a lever arm 30, to the upper portion of which an operating chain or the like 31 is adjustably connected. As shown in Fig. 9, the chain 31 is given a horizontal oscillating movement by passing it around sheaves 32 and 33 and connecting it to a crank arm 34 mounted on a crank disc 35 rotated by an electric motor 36. The opposite end of the chain 31 is passed around sheaves 37 and 38 and supports a suitable counterweight 39. The angle of throw of the lever arm 30 may be varied by shifting the point of connection of the chain 31 thereto to thereby change the effective radius of the lever arm. The described parts are preferably proportioned so that the spreader plate 5 will be moved about its longitudinal axis to a maximum of about 450 in each direction, so that when tilted the spray will impact at different levels on the side walls 17 and 18.

If the pipe 20 were maintained in the horizontal position and continuously oscillated about its axis, the spray would cover an area of generally butterfly form on the rear wall with an excessively wet area at the axis of the formation. To provide a more uniform distribution of the spray deposits over a greater area on the rear wall, the spray nozzle is desirably given a simultaneous oscillating movement in a vertical plane. The mechanism for this purpose consists of an arm 40 secured to the outer end of the plate 22 and having an operating chain or the like 41 adjustably connected for raising the arm and thereby the plate 22 about the pivot pin 23. As shown in Fig. 9, the chain 41 passes upwardly around sheaves 42 and 43 and is connected at its lower end to a crank arm 44 on the disc 35 and on an extension of which the crank arm 34 is formed.

The desired range of movement of the arm 40 being normally less than that of the lever 30, the crank arm 44 is positioned closer to the axis of the disc 35 than the crank arm 34. With this arrangement the arm 40 will be periodically raised to the upper position indicated in Fig. 6, and returned to the lower position by gravity due to the greater weight of parts at the outer side of the pivot pin 23. The range of the vertical oscillations can be varied by shifting the point of connection of the chain 41 to the arm 40. The movements of the chains 31 and 41 are advantageously synchronized so that the spreader plate 5 will not be tilted relative to its longitudinal axis when the spray nozzle is in its extreme upper and lower positions and be progressively tilted to opposite extreme positions when the pipe 20 is horizontal.

This desired synchronization is effected by connecting the chains to the common driving disc 35 and angularly spacing the crank arm 34 relative to the disc 900 in advance of the arm 44, as shown in Fig. 10. Thus with the operating parts relatively arranged as indicated in Figs. 9 and 10, the pipe 20 would be horizontal and the spreader plate tilted to its maximum position facing the side wall 17. During one complete revolution of the crank disc 35 from this position in the direction indicated, the spray nozzle will be continuously moved first to its extreme lower position in which the spreader plate will be untilted relative to its longitudinal axis, then to the intermediate position wherein the spreader plate will be tilted to its maximum position facing the side wall 18, then to its extreme upper position in which the spreader plate will be untilted, and finally to its original horizontal position wherein the spreader plate is tilted toward the side wall 17.

In the operation of the recovery furnace shown, the spray particles produced are of sufficient size and at sufficient velocity that they will not burn during their flight across the furnace in contact with the ascending stream of high temperature gases, but dried sufficiently to be in a sticky condition when impacting on the furnace walls towards which they are directed. The particles tend to coalesce on the walls in the form. of adhering masses of successive layers which build out into the furnace, as shown in Figs. 4 and 5.

The coalesced masses of sprayed material are in position to receive heat by radiation from the furnace bed and to contact by the ascending high temperature gases, causing the gradual evaporation of most of the remaining moisture and the distillation of some of the low temperature volatiles, whereby the deposited material assumes a porous character. The material contains substantially all of its original organic content and each portion continues to adhere to the wall on the surrounding mass until the gravity effect thereon is sufficient to overcome the forces of adhesion or cohesion, whereupon it breaks off in lumps of various size falling into the lower section of the furnace and burning on the hearth thereon. The speed of the motor 36 and therefore the rate of movement of the spray nozzle 10 can be varied with changes in load and furnace conditions to vary the thickness of the deposited layers and the time of direct exposure to the furnace of each layer of deposited material. The spray nozzle mechanism described is thus a highly useful part of the furnace and process control mechanism.

In Fig. 11 is illustrated a modified form of spray nozzle mount and oscillating mechanism for providing in addition to the vertical tilting and axial oscillating movements of the mechanism heretofore described, an additional oscillating movement about a vertical axis. The last mentioned movement is for the purpose of distributing any accidental streamers in the spray over a different path on the walls and thereby reducing the tendency to form wet spots. In this construction the supporting plate 22a is pivoted in a U-shaped bracket 50 carried by a vertical shaft 51. The shaft 51 is mounted for rotary movements about its vertical axis in a bracket 52, and carries an outwardly extending horizontal lever arm 53 at its lower end. The pipe 20 is provided as heretofore described with an oscillating lever arm 30a, which is operatively connected to the crank arm 34 by a link 54. The vertical tilting movements are effected by means of a bar 40a on the under side of the plate 22a adjustably connected to a link 55 which.is actuated through a bell crank lever 56 and a second link 57 connected to the crank arm 44. The lever 53 is oscillated by means of a link 58 adjustably connected to the lower arm of the bell crank lever 56. The various oscillating movements are preferably synchronized so that the spreader plate will be alternately in its maximum tilted positions about its longitudinal axis when the nozzle is in its horizontal intermediate position in the wall opening, and the nozzle pointing toward the side wall 18 with the spreader plate untilted relative to its longitudinal axis when in its uppermost position, and pointing slightly toward the side wall 17 with the sprayer plate untilted relative to its longitudinal axis when the nozzle is in its lowermost position. The amplitude of each oscillating movement can be independently adjusted to control 'the area of impact on the furnace walls. While in accordance with the provisions of the statutes we have illustrated and described herein the best forms of our invention now known to us, those skilled in the art will understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by our claims, and that certain features of our invention may sometimes b~ used to advantage without a corresponding use of other features.

We claim: 1. A spray nozzle comprising a central discharge pipe having a discharge passage of circular cross-section, a spreader plate spaced from the discharge end of said discharge passage and having a flat surface arranged in the path of discharge of and at an oolique angle to the axis of said discharge passage, and a circular hood surrounding and projecting beyond the discharge end of said discharge pipe, the projecting end of said hood being in contact with and welded to said spreader plate along a substantial portion of its circumference, a portion of said spreader plate extending beyond said hood and being of substantially elliptical form.

2. In combination, a spray nozzle comprising a discharge pipe and a spreader plate spaced from the discharge end of said discharge pipe and arranged in the path of discharge of and at an angle to the axis of said discharge pipe, and means arranged to simultaneously oscillate said spray nozzle about a vertical axis, a transverse horizontal axis and a longitudinal axis.

3. In combination, a spray nozzle comprising a discharge pipe and a spreader plate arranged in spaced relation in the path of discharge from . and at an angle to the axis of said discharge pipe, and means for simultaneously oscillating said spray nozzle about a vertical axis, a transverse horizontal axis and a longitudinal axis, said means having adjustments to permit independent regulation of the amplitude of each of said oscillations.

4. In combination, a spray nozzle comprising an inclined discharge pipe, a spreader plate spaced from the lower end of said discharge pipe and arranged in the path of discharge of and at an acute angle to the axis of said discharge pipe, and a circular hood surrounding and projecting beyond the lower end of said discharge pipe, the lower end of said hood being in contact with and connected to said spreader plate along a portion of its circumference, and means arranged to simultaneously oscillate said spray nozzle and spreader plate about a transverse horizontal axis and about a longitudinal axis. 5. In combination, a spray nozzle comprising an inclined discharge pipe, a spreader plate spaced from the lower end of said discharge pipe and having a flat upper surface arranged in the path of discharge of and at an acute angle to the axis of said discharge pipe, and a circular hood surrounding and projecting beyond the lower end of said discharge pipe, one circumferential portion of the lower end of said hood being in contact with and welded to said spreader plate with the remaining circumferential portion in a transverse plane intersecting said spreader plate adjacent the point of Intersection of the axis of said discharge pipe, and means for simultaneously oscillating said spray nozzle about a vertical axis, a transverse horizontal axis and a longitudinal axis.

6. In combination, a liquid supply pipe having spray means at its discharge end producing a substantially horizontal flat spray, sleeve means supporting said supply pipe and permitting oscillation of said supply pipe about its longitudinal axis, means for pivotally supporting said sleeve means fnr tilting mwovements ab + mt +t e WMo *-UMV Ja Iansverse hor0zontal axis, an electric motor, and means operatively connecting said motor to said sleeve means and supply pipe and arranged to synchronously oscillate said sleeve means about said transverse horizontal axis and said supply pipe about its longitudinal axis.

7. In combination, a liquid supply pipe having spray means at its discharge end producing a substantially horizontal flat spray laterally offset from the longitudinal axis of said supply pipe, sleeve means supporting said supply pipe and permitting oscillation of said supply pipe about its longitudinal axis, means for pivotally supporting said sleeve means for tilting movements about a transverse horizontal axis, a continuously rotating electric motor, and means operatively connecting said motor independently to said sleeve means and supply pipe and arranged to continuously and synchronously oscillate said sleeve means about said transverse horizontal axis and said supply pipe about its longitudinal axis.

8. In combination, a liquid supply pipe having spray means at its discharge end producing a substantially flat spray in a plane inclined relative to the longitudinal axis of said supply pipe, means arranged to oscillate said supply pipe about a transverse horizontal axis, means arranged to oscillate said supply pipe about its longitudinal axis, said oscillating means being synchronized to provide a spray discharge in a plane parallel to said horizontal axis in the extreme upper and lower positions of said spray means and in oppositely inclined planes at the limits of the oscillations of said supply pipe about its longitudinal axis.

9. In combination, a liquid supply pipe having spray means at its discharge end producing a substantially flat spray in a plane inclined relative to the longitudinal axis of said supply pipe, sleeve means supporting said supply pipe and permitting oscillation of said supply pipe about its longitudinal axis, means for pivotally supporting said sleeve means for tilting movements about a transverse horizontal axis, an electric motor, means operatively connecting said motor to said sleeve means and arranged to oscillate said sleeve means about said transverse horizontal axis, means operatively connecting said motor to said supply pipe and arranged to oscillate said supply pipe about its longitudinal axis, said connecting means being synchronized relative to said motor to provide a spray discharge in a plane parallel to said horizontal axis in the extreme upper and lower positions of said spray means and in oppositely inclined planes at the limits of the oscillations of said supply pipe about its longitudinal axis.

10. A spray nozzle comprising a discharge pipe having a restricted spray orifice of circular crosssection at its discharge end, a spreader plate spaced from and of substantially greater width than the discharge end of said discharge pipe and arranged in the path of discharge of and at an oblique angle to the axis of said discharge pipe, and a hood rigidly mounted on said discharge pipe completely surrounding in spaced relation with and projecting beyond the discharge end of said discharge pipe, the projecting end of said hood being in contact with and integrally connected to said spreader plate along a substantial portion of its periphery.

11. A spray nozzle comprising a discharge pipe having a restricted spray orifice of circular crosssection at its discharge end, a spreader plate spaced from the discharge end of said discharge pipe and arranged in the path of discharge of and at an oblique angle to the axis of said discharge pipe, and a circular hood rigidly mounted on said discharge pipe surrounding and projecting beyond the discharge end of said discharge pipe, one circumferential portion of substantial extent of the projecting end of said hood being in contact with and integrally connected to said spreader plate with the remaining portion arranged in a different plane intersecting said spreader plate and out of the main path of the spray impinging on said spreader plate.

12. A spray nozzle comprising an inclined discharge pipe having a restricted spray orifice of circular cross-section at its discharge end, a spreader plate spaced from the lower end of said discharge pipe and arranged in the path of discharge of and at an acute angle to the axis of said discharge pipe, and a circular hood surrounding in spaced relation with and projecting beyond the lower end of said discharge pipe, one circumferential portion of the lower end of said hood being in contact with and connected to said spreader plate with the remaining circumferential portion in a different plane intersecting said spreader plate at a substantial angle adjacent the point of intersection of the axis of said discharge pipe.

13. In combination, a spray nozzle comprising a discharge pipe having a restricted spray orifice of circular cross-section at its discharge end and a substantially flat spreader plate spaced from the discharge end of said discharge pipe and arranged in the path of discharge of and at'an acute angle to the axis of said discharge pipe so as to produce a substantially flat spray, and means arranged to continuously oscillate said spreader plate about the longitudinal axis of said discharge pipe.

14. In combination, a spray nozzle comprising a discharge pipe having a restricted spray orifice at its discharge end and a spreader plate spaced from the discharge end of said discharge pipe and arranged in the path of discharge of and at an angle to the axis of said discharge pipe so as to produce a substantially flat spray, and means arranged to continuously oscillate said spray nozzle and spreader plate about a vertical axis.

15. In combination, a spray nozzle comprising a discharge pipe and a spreader plate spaced from the discharge end of said discharge pipe and arranged in the path of discharge of and at an angle to the axis of said discharge pipe so as to produce a substantially flat spray, and means arranged to simultaneously oscillate said spray nozzle and spreader plate about a transverse horizontal axis and about the longitudinal axis of said discharge pipe.

16. In combination, a spray nozzle comprising a discharge pipe having a restricted spray orifice at its discharge end and a substantially flat spreader plate spaced from the discharge end of said discharge pipe and arranged in the path of spray discharge at an angle to the axis of said discharge pipe so as to produce a substantially flat spray, and means arranged to continuously bodily move said spray nozzle in oscillations about a transverse horizontal axis and a laterally offset longitudinal axis. LESLIE S. WILCOXSON.

FREDERIC G. ELY.