US 3771724 A
A pressure nozzle for spraying liquid as droplets substantially free from droplets of sizes that will form a mist which will drift. A first liquid sheet is conducted along a wall that extends beyond the nozzle orifice. A second liquid sheet intersects the first sheet on the wall, and the resultant stream, which is discharged into the atmosphere, disrupts into droplets in a controlled manner.
Description (OCR text may contain errors)
United States Patent 1 Rose et al.
APPARATUS AND PROCESS FOR SPRAYING LIQUIDS 1 Inventors: Clark B. Rose, Grange; Richard B.
Kelley; Richard B. Ravitts, both of Rockford, all ofi lll.
Assignee: Richards of Rockford, Rockford,
Filed: July 19, 1972 Appl. No.: 273,181
U.S. Cl 239/221, 239/456, 261/120 Int. Cl. F23d ll/04 Field of Search 239/17, 22, 221,
References Cited UNITED STATES PATENTS 5/1909 Helm 239/440 in] 3,771,724 Nov. 13, 1973 780,780 1/1905 Culley 239/440 2,342,596 2/1944 North... 239/215 3 ,640,5 l4 2/1972 Albritton 3,416,729 12/1968 Ravitts et al..... 2,530,808 11/1950 Cerasi 239/440 Primary Examiner--Allen N. Knowles Assistant Examiner-Gene A. Church Attorney-I-lenry L. Brinks  ABSTRACT A pressure nozzle for spraying liquid as droplets substantially free from droplets of sizes that will form a mist which will drift. A first liquid sheet is conducted along a wall that extends beyond the nozzle orifice. A second liquid sheet intersects the first sheet on the wall, and the resultant stream, which is discharged into the atmosphere, disrupts into droplets in a controlled manner.
I 26 Claims, 15 Drawing Figures PATENTED NOV 1 3 I973 SHEEI 1 CF 4 Vf/V/l CONTRACT/J PATENTED NOV 13 1975 SHEET 2 BF 4 Ill/LET lNlET j iii":
Z "FTP" 0 5 j 6 :I E E F APPARATUS AND PROCESS FOR SPRAYING LIQUIDS FIELD OF THE INVENTION This invention relates to an apparatus and method for spraying liquids usable for cooling, aeration, condensing, humidification or stripping of dissolved or entrained gases. More particularly, this invention relates. to an apparatus and method in cooling water for optimizing the size range and number of the droplets in a water spray, the trajectory, and the ratioof velocity head to static head, in order to improve the approach to maximum heat transfer without undesirable atomiza tion that createsa mist that will drift.
BACI (GROUND'OF THE INVENTION The need for cooling, aeration, condensing, humidification or stripping of dissolved or entrained gases from liquids iswell known. The burgeoning need for cooling large volumes of water in electrical utility generating plants, industrial condensing or cooling systems, and commercial and industrial air conditioning systems, also is well known. The expanding nuclear power indu'stry in particular has beenplagued currently with the problem of cooling large quantities ofwater in orderto reduce the temperatures of the thermal discharge from generating stations for ecologically oriented reasons.
While cooling towers frequently provide a satisfactory solution to some cooling problems, there arev many situations in which the demands for high volume. cooling indicate cooling by spraying to be the desirable'economically and technically feasible solution.
In cooling water by spraying, the cooling is largely caused by evaporation termed mass transfer. The heat exchange as the result of conduction between the air and water is termed sensible heat transfer. The total" rate of heat transfer is a. function of the water surface area which the air is able to contact and the humidity and temperature of the contacting air and the temperature of the water. i
The total rate at which heat is removed from a particle of water by both sensible heat and mass transfer is given by the following formula:
Q, rate at which heat is removed by both heat and mass transfer; BTU/hr.
a r a qr ntrBT llihr).i qattililfl:
A transfer areibfi'fi ugo drops (sq. ft.) T w temperature of the H drops (F) T temperature of the surrounding air (F) K mass transfer coefficient (1b,, H O/hr) (sq.
ft.) (unit humidity driving force on mass basis) 0. humidity of saturated air at temperature 0 spray (T (1b,, I-I O/lb,, dry air) i Q humidity of saturated air at the temperature of surrounding air (T (lb H O/lb dry air) Ahl latent heat of vaporization of H 0 at temperature of spray (T BTU/1b,, It will be observed from the foregoing that the. rate at which heat is removed from the water particles is directly proportional to the surface area of the particles. It is readily apparent from the above that less heat transfer will occur from a spray device that produces primarily a sheet of water than from one that produces droplets. More droplets, and therefore, the smaller size droplets,.result in the greatest surface area, and therefore the greatest rate of heat transfer. On the other hand, if the droplet size is very fine, a mist is formed which can drift, cause damage to the surrounding areas, and produce adverse ecological disturbances. Spray devices for salt water are potentially troublesome, since any mist drift can cause especially severe damage. Water in mist also reduces the cooling efficiency' because cold water is lost from the system.
Spray devices can be used advantageously to aerate water to prevent stagnation, to enrich the oxygen content. of the water, to humidify air, or to strip dissolved or entrained gases from water or liquids. In each of the foregoing uses droplet size in the spray is important to the efficiency of the device.
l-leretofore, a wide variety of spray nozzles have been employed"for'atomization of liquids. They may be classified as: spinning mechanical nozzles; pressure nozzles; and gas atomizing nozzles. Certain specialized nozzles are a combination of the foregoing, such as a combination of gas and spinning mechanical atomization. A form of mechanical spinning nozzle for cooling water is illustrated in Ravitts- US Pat. No. 3,416,729. The common pressure nozzle for atomization has a spiral through which the water passes at high velocity. As it leaves the orifice, centrifugal force disrupts the water and shatters it into the numerous droplets of spray.
SUMMARY OF THE OBJECTIVES OF THE INVENTION A general object of the present invention is to provide'anew and improved pressure nozzlefor generating an improved liquid spray, and which is adaptable for use-in a spray unit operable to accomplish heat, air, water, or gas transfer to or from a liquid.
A further object is to provide a spray nozzle which achieves improved droplet size of the spray so as to achieve improved performance in the economical transfer of heat'and/or water vapor into the surrounding atmosphere.
A still further object is to provide a spray device for controlling the spray trajectory and/or energy optimization through control of the ratio of velocity head to static head at the orifice.
In environmental conditions where prevailing atmospheric wind velocity is high, and where wind drift or loss from the spray presents the possibility of undesirable contamination of the surrounding area, there is a need for minimizing the mist. Accordingly, it is a further object of the invention to provide a spray device that produces minimal mist drift loss, and, further, which may be adjusted to vary the mist drift loss while optimizing the ratio of static head to velocity head available from the pump or energy source, thereby to optimize the performance of the spray unit to existing conditions and attain maximum transfer of heat and/or water vapor to the atmosphere.
It is another objective of the invention to provide a novel spray nozzle which disrupts the liquiddischarged from a nozzle and causes it to shatter into numerous droplets of a size range for improving the approach to optimum heat transfer.
It is yet another object of the invention to provide a nozzle and spray device, especially suitable for spraying large quantities of liquid at a high rate.
It is another object of the invention to provide a method and apparatus which reduces the cost of cooling, aeration, condensing, humidification, or stripping of entrained gases from liquids.
Further objects of the invention will be apparent from a review of the attached specification and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged fragmentary diagrammatic view of a nozzle embodying the principles of the invention.
FIG. 2A and 2B are fragmentary diagrammatic views illustrating in cross section spray units having nozzles embodying the principles of the invention.
FIG. 3 is a cross-sectional view with some parts in elevation showing a spray unit containing a nozzle embodying the principles of the present invention.
FIG. 4 is an enlarged fragmentary cross sectional view showing the parts for adjusting the nozzle in the spray unit of FIG. 3.
FIG. 5 is a fragmentary perspective view of one form of the floating spray unit embodying the novel features of the present invention.
FIG. 6 is a somewhat diagrammatic longitudinal cross-sectional view of another form of the floating spray unit embodying the invention.
FIG. 7 is an enlarged transverse cross-sectional view of a spray unit with parts broken away and shown in cross-section illustrating a modified form of nozzle embodying the invention shown in FIG. 6.
FIG. 8 is a diagrammatic top plan view of the device illustrated in FIG. 6.
FIGS. 9A, 9B, 9C, 9D and 9E are diagrammatic illustrations in elevational cross-section of various systems for employing the device illustrated in FIGS. 6 to 8.
FIG. 10 is a cross-sectional view with parts broken away showing still another type of a spray unit embodying the principles of the invention containing a plurality of nozzles.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Briefly stated, the present invention relates to a novel pressure nozzle that projects liquid as a spray of numerous droplets. It is a discovery of the invention that droplets of a desired size range and number are produced by generating a sheet of liquid on one side of a nozzle orifice which is intersected by at least one other sheet against a wall prior to the discharge of the resulting liquid stream.
In one form of the invention, two liquid sheets leave the nozzle orifice at a predetermined controlled angle acute to each other, and one sheet impinges against the other on a wall positioned outside of the orifice. The velocity and angular relationships of these two sheets cause the resulting liquid stream to disintegrate in a predictable way, resulting in predetermined average size range and number of particulate droplets. The droplets are ejected to a selected height into the atmosphere in a trajectory for optimum dwell time, for the minimization of droplet coalescence, and for the minimization of wind drift.
In a preferred form of the invention, the radial width of the orifice is selectively adjustable so that, if desired, the thickness of the resulting liquid stream exiting the orifice may be varied. In this way, the radial width of the stream of water exiting the orifice may be reduced so as to increase the static head from the pump or energy source; conversely, adjustment of the radial width of the orifice can be increased to reduce the height of the spray and the diameter of the spray pattern thereby to increase the flow rate or velocity head from the pump or energy source.
In one embodiment of the invention, the liquid under pressure is directed outwardly through a chamber'and then through a biangular nozzle orifice extending in a circle around the periphery of the chamber from which it is discharged upwardly into the atmosphere.
In a preferred embodiment, the invention comprises the novel construction of a chamber having a peripherally located orifice together with the manual adjustments for varying the radial width of the nozzle orifice throughout its circular extent so as to selectively control the liquid discharge in order to optimize the performance of the spray unit to existing conditions and attain maximum transfer of heat and/or water vapor to the atmosphere.
Moreover, the radial width of the orifice and the resulting trajectory from the biangular nozzle may be independently varied to optimize all operational conditions.
In a preferred form, the nozzle of the invention is usable on the spray unit as a self-contained assembly with its own pump supported on a buoyant float anchored in any desired location or with other units in a pattern in a channel, pond, lake, or tank. It may be used equally advantageously, however, with spray units having fixed supports, such as a pier, stand, or truss-mount pier. In some instances, it may be advantageous to remotely locate a pumping unit from the spray unit.
Referring now to FIG. 1, a nozzle illustrating the principles of the invention is diagrammatically depicted. Liquid under pressure is supplied to the nozzle orifice 10 from which it is projected into the atmo sphere as it is guided along the surface of wall member 11. The wall member 11 extends from an inlet end 15 to an outlet end 17, the latter of which terminates at a point downstream from the orifice 10. The inlet end 15 is positioned a distance upstream of the orifice 10 sufficient for generation of a unidirectional sheet of liquid A along wall 11, which sheet is laminar adjacent the wall 11, that is conducted downstream to, and outside of, the orifice. A second wall 12 is positioned to generate a second unidirectional sheet of liquid B along wall 12, which second sheet is laminar adjacent wall 12, and to direct such second sheet B for intersection with the first sheet A along the extent of wall 11 exterior to the orifice and before the end 17. The resulting stream of liquid C formed by intersecting sheets A and B is turbulent and unstable, and disrupts and shatters into droplets as it is projected into the atmosphere.
The second wall member 12 has an inlet end 14 and an outlet end 16, the latter of which is spaced from the wall member 11 to form the orifice 10. The outlet end of the wall 12 is spaced from and positioned so that the two sheets A and B intersect within the extent of wall 11 between the inlet end 15 and the discharge end 17. The distance between the end 16 of wall 12 and wall 1 l is substantially constant along the peripheral edge of end 16, but may be selectively adjusted in order to vary the thickness of the resulting sheet C and to change the droplet size as will be more fully explained hereinafter. The end 16 of wall 12 is spaced from wall 11 so that the total area of the orifice 10 is less than the supply conduit in order to obtain a predetermined increase in the velocity pressure head of the liquid relative to the static head at the nozzle orifice.
The wall 12 is offset from parallel with respect to wall 11 at an acute angle so that the liquid sheet on wall 12 intersects liquid sheet on wall 11 at an acute angle. The acute angle between wall 12 and wall 11 illustrated in the drawings is 30, although it may vary widely in the range fromabout to about 80. The orifice between the walls 11, 12 normally would produce a vena contracta in the discharged stream.
The wall 11 extends at least beyond a point corresponding to the inside'surface of wall '12 if the latter were extended beyond orifice 10. The wall 11 thereby provides an area for intersection of the two sheets and for effectively guiding the trajectory of the emerging stream. It has been determined that a majority of the droplets produced by the nozzle of the invention are in the size range from 0.25 inch to about 0.75 inch. It has also been determined that the spray produced by the nozzle of the invention is substantially free from droplets of a size less than about 30 microns which cause mist that can drift.
Referring now to FIGS. 2A and 28, there is illustrated a form of the invention suitable for spraying large volumes of liquid. The nozzle orifice 10 is circular. The first wall 1 l is in the form of an inverted frustocone supported on a generally horizontally extending cover plate 20. The second wall 12 is in the form of a cylinder encompassing the lower portion of the frustoconical wall 1 1. Wall 12 is supported by a plate 21. The space between plates and 21 defines a plenum chamber 22 for distributing liquid from a pressure source through inlet 24 to the nozzle orifice 10. The source of liquid under pressure may be supplied by any suitable pressure head, for example from a remotely located pumping mechanism. The liquid under pressure is supplied to the plenum chamber 22 from above (FIG. 2A) or below (FIG. 2B).
As indicated by the arrows in FIGS. 2A and 2B, the liquid under pressure enters the spray unit through inlet 24 and then is distributed through the plenum chamber 22 to the nozzle orifice 10 from which it is projected at C into the atmoshere. In the nozzle, two sheets are produced by biangular walls 11 and 12. The sheet produced by wall 12 intersects the sheet produced on the wall 11 to create the unstable condition in the resulting stream C projected into the atmosphere so that the stream C disrupts and shatters into the droplets, as explained heretofore in connection with FIG. 1.
It will be noted that the trajectory of the stream C, and hence the dwell time of the droplets in the atmosphere, is determined by the angle of wall 11. The wall 11 may be at an angle offset from vertical in a wide range, for example, in cooling systems from 10 to 80, although for other purposes the wall 11 will be offset at different angles. In the devices-shown in FIGS. 2A and 2B, the trajectory of the stream C can be changed by changing the angle of wall 11, which may be accomplished by substituting another cover plate 20 having the wall 11 offset at a different angle.
It will be noted that the end of wall 12 is spaced from wall 11 a predetermined substantially fixed amount throughout the circular extent of wall 12. The predetermined spacing controls the size of the droplets throughout the extent of the nozzle 10. The total area between wall 12 and wall 11 is less than the cross-sectional areaof the supply conduit 24 in order to increase the velocity pressure head relative to the static pressure head at the nozzle orifice 10.
Referring now to FIG. 3, there is shown a spray unit 30 incorporating the nozzle of FIGS. 1 and 2, and which is suitable for use in cooling a parent body of liquid 31. The parent body of liquid 31 may be a canal, stream, lagoon, tank, river, pond, or the like, which is heated, for example, by the hot water discharge of an electric utility generating facility, such as a nuclear or fossil-fuel powered electrical generating plant. The spray unit 30 projects a spray C from the parent body into the atmosphere to cool by latent and sensible heat transfer. I
The spray unit 30 incorporates an axial-flow type pump in the form of an impeller or turbine 40 driven by motor 44. The impeller 40 includes a plurality of angularly spaced plates 43 radiating outwardly from the shaft 41 to cut through and propel the water upwardly through a conduit 36. Conduit 36, which extends vertically through the center of the unit, acts as a passage for accommodating the flow of water from the parent body 31 to the plenum chamber 22, as well as acting as a pump chamber bounding the blade tips of the impeller 40.
At its lower inlet end, the pump intake may depend from a throat 37 with a downwardly flaring intake shroud 39 immersed in the water, establishing an entry way into the throat 37. The unit, however, will function with or without the intake shroud, and the use of the intake shroud is to control the minimal depth below the surface at which intake water is to be withdrawn, thus controlling the mixing performance in the parent body of liquid 31. Likewise, various accessory intake arrangements are possible for spray unit 30, for example anti-erosion plants (not shown) suspended so as to discourage vertical flow directly below the intake shroud, to discourage the establishment of eddy currents, and to establish a relatively horizontal intake flow profile; intake draft tubes (not shown for selective predetermined mixing required as progressive contacting is established through the path of the water flow in the parent body; intake screens (not shown) of a variety of designs may be employed to protect the pump from ingestion of foreign objects, and the like.
The impeller, or turbine 40 may be driven by an electric motor 44. While there are many different possible ways of supporting the motor, the structure shown in FIG. 3 illustrates a preferred structure.
s shown in FIG. 3, electric motor 44 is mounted on a platform 45 which is supported above the cover plate 20 by a plurality of upstanding legs 47. The legs extend up-wardly along the outer wall of the conduit 36 from a ring 49 encircling the conduit and welded thereto. The upper end portions of the legs pass through plenum chamber 22 and define wide flow passagesbetween the bottom wall 21 and cover plate 20, for the water to flow outwardly to the biangular nozzle 10. Supporting the platform ontop of the legs is a metal disc 50 which is welded to the upper ends of the legs and includes a central opening to allow passage therethrough of the impeller shaft 41. The platform 45 is above the disc 50 and includes two spaced circular plates 51, each of which have central openings for the impeller shaft. The plates 51 are separated by braces 55 which are welded at their upper and lower ends to the plates.
The unit 30 may be supported in the parent body of liquid 31 by any suitable means such as by overhead supports, underwater piers and stands, or by floats.
In operation of spray unit 30, water is pumped upwardly from the parent body 31 through shroud 39, throat 37, conduit 36, and then diffused laterally by the plenum chamber 22 toward the orifice 10. The nozzle orifice 10 projects the water into the air as previously explained in connection with FIGS. 1, 2A and 2B.
In the spray unit 30 of FIG. 3, the radial width 'of the orifice 10 is substantially the same throughout the length thereof. The radial width may be selectively'adjusted, however, to change the thickness of the stream C and thus the characteristics of the resulting spray. If the temperature and humidity of the air are high(e.g., in the summer), the radial width of the orifice may be reduced to decrease the thickness of the sprayed sheet and thus cause the formation of smaller water droplets which are closable of losing heat more rapidly. If temperature and humidity conditions are more favorable as in the winter, the radial width of the orifice may be made greater to increase the thickness of the sheet and cause the formation of larger droplets when the sheet disintegrates. The larger droplets are more stable and are not as susceptible to being blownby the wind into areas surrounding the parent body. Thus, the creation of larger droplets results in a reduction in the possibility of wind drift beyond the channel or basin of the parent body of water giving control of precipitation which might wet the surrounding areas, while the creation of smaller droplets results in greater heat transfer and therefore greater cooling under high temperature and humidity conditions. In addition to being adjusted in accordance with the temperature and humidity conditions, the orifice also may be increased or decreased in width depending upon whether cooling requirements are low or high.
To adjust the width of the orifice 10 in spray unit 30, the cover plate is flexible vertically so that its outer edge 29 may be adjusted selectively in height relative to the bottom wall 21 of the chamber 22. Vertical movement of the peripheral outer edge of the cover plate 20 controls the width of the orifice because the wall 11 tapers downwardly and inwardly above the outlet end of wall 12. As the cover plate 20 is flexed upwardly, the orifice 10 is opened wider because the distance between the outlet end of wall 12 and the wall 11 is increased. Conversely, as the outer edge of cover plate 20 is flexed downwardly,-the orifice is decreased in the width. To move the cover 46 up and down, and thus adjust the size of the orifice 10, angularly spaced bolts 60 are fastened to the bottom wall 21 of the chamber 22 and extend upwardly through the chamber and through openings in the cover plate 20.
As best shown in FIG. 4, collars 61 and nuts 62 screwed on the bolts 60 hold the cover plate in a selected vertical position and may be threaded upwardly or downwardly on the bolts 60 to adjust the height of the outer edge 29 of the cover plate 20 relative to the bottom wall 21 of the chamber 22. One such bolt, nut and collar arrangement is shown in FIG. 4 wherein the bolt 60 includes a lower head welded at 65 to the bottom wall 21 of the chamber. The body of the bolt extends vertically through the chamber 22 and includes a threaded upper end portion 66 projecting through the opening 75 in the cover. The collar 61 is screwed on the upper end of the bolt and includes a lower flange 67 which engages the inner surface of the cover and an upper threaded shank 68 projecting upwardly through the opening. Flats located on opposite sides of the upper end of the shank advantageously permit the collar to be turned and threaded upwardly and downwardly on the bolt without disassembling any part of the spray unit. In addition, the outer surface of the shank is threaded to receive the nut 62 which engages the outer surface of the cover plate 20 around the opening so that the cover plate 20 is held between the flange and the nut. By loosening the nuts and threading the collars upwardly on the bolts, the cover plate 20 may be deflected upwardly by the flanges 67. The cover plate 20 may be deflected downwardly by threading the collars downwardly on the bolts and then by forcing the cover plate 20 downwardly with the nuts as the latter are threaded downwardly on the shanks 66. Thus, the outer edge of the cover plate 20 may be deflected upwardly or downwardly to control the width of theorifice 10 to any selected width using a spacer gauge for uniform adjustment around the periphery if desired.
Referring now to FIG. 5, the spray unit 30 depicted in FIGS. 3 and 4 may be supported on the surface of the parent body of liquid by bouyant float 80. The spray unit on the float may be moored at a given location in the body of water by stringing cables (not shown) from the shore to the eyes 81 angularly spaced around the periphery of the float. The float may be formed of a stainless steel outer shell 84. The outer shell 84 is filled with a low density material 85, such as polyurethane foam. Although other forms for supporting the spray unit may be used, as heretofore mentioned, the float supported unit has proved to be particularly advantageous.
The spray nozzle of the invention may assume various configurations. In FIGS. 2A through 5, the orifice is circular. As illustrated in FIGS. 6-8, the orifice is straight.
Referring now to FIG. 8, there is shown in top plan view a float supported spray unit 30'. The bouyant float of a rectangular configuration has spray orifices l0 and 10" located on opposite sides and extending substantially the length of the float along a straight line. A motor 44' supported centrally of float 80' is used to drive a turbine which is supplied water through an intake plenum chamber 39' that extends longitudinally along the length of the float.
Referring now to FIG. 6 and 7 the water received into intake plenum chamber 39' through intake openings 37' and 38 is delivered by turbine to discharge plenum chamber 22' from which it is projected into the atmosphere through the orifices l0 and 10". The turbine 40 has blades 43 mounted within a cylindrical conduit 36. The intake plenum chamber 39' is provided on opposite sides with intake openings 37' and 38. The ends of cover plate 20 are sealed to wall 21' by suitable means (not shown), so that the water is sprayed through the nozzles 10', 10 located at the side of the spray unit.
The discharge plenum chamber 22' is formed between walls 20' and 21' for conducting liquid to orifices l0 and 10" located at opposite sides of the plheum chamber. Each orifice is in the form of a straight line which may approximate the length of the float.
A first wall member 11' is secured to cove plate 20". A second wall 12' projects a stream of liquid against wall 11' as described in connection with FIGS. 1-5. A nut and bolt assembly 60' as depicted in FIG. 7 may be used to vary the width of orifice 10 as more fully described in connection with FIG. 4 hereinabove.
In operation, the device shown in FIGS. 6-8 forms a first liquid sheet on wall 11' which is intersected by a second liquid sheet formed on and projected from wall 12' against wall 11'. If it is desired to vary the width of the orifice l0, bolt and nut assembly 60' is used to move wall member 11' to the desired new position.
The device depicted in FIGS. 6-8 may be employed in various situations for producing various effects as shown diagrammatically in FIGS. 9A through 9E. As illustrated in FIG. 9A, the spray unit 30' may be mounted cross-wise to a channel having a water flowing direction indicated by arrow F. The water is drawn into the spray unit 30' on both the upstream and downstrem sides of the intake as shown by the arrows, and sprayed through the nozzle both upstream and downstream in what is characterized as Mixed Flow. 0n the other hand, as shown in FIG. 9B the downstream intake and spray orifice may be blocked so that the water is withdrawn and discharged only on the upstream side of the spray unit in what is characterized as Reverse Recy- I cle. Another variation is illustrated in FIG. 9C in which the water is withdrawn on the downstream side and discharged on the upstream side in what is termed Reverse Spray. Another arrangement is a Forward spray illustrated in FIG. 9D in which the intake is on the upstream side and the spray is on the downstream side of the spray unit. A Forward Recycle is illustrated in FIG. 9E in which the water is withdrawn and discharged from the downstream side of the spray unit.
Another form of spray device is shown in FIG. 10 in which a plurality of orifices are employed in a spray unit to spray in the same direction by spraying at differing angles. As depicted in FIG. 10, two nozzles I 10 and 210 spray liquid into the atmosphere. The nozzle 110 has a frusto-conical wall 111 which projects spray into the atmosphere at an angle of about 45. A second nozzle 210 has a frusto-conical wall 211 which guides the spray into the atmosphere at an angle of about offset from vertical.
Nozzle 110 is provided with a frusto-conical wall 111 and a generally vertical wall 112. The wall 112 conducts a liquid sheet which intersects aliquid sheet on wall 1 1 1, as shown in connection with FIG. 1. Similarly, nozzle 210 is provided with a wall 211 in the form of a frusto-conical member. A second wall 212 is vertically positioned for conducting a stream that intersects with a streamon wall 211 as described in connection with FIG. 1.
The size of the orifice nozzle 110 is selectively adjustable by a nut and bolt assembly 160, the type previously described in connection with FIGS. 3 and 4. Likewise, the size of nozzle 210 can be selectively adjustable by a similar nut and bolt assembly 260.
The cover plate 120 terminates at nozzle 210 in a downward skirt 212 forming one wall of the biangular nozzle 210. The cover plate 120 is supported at its inner end by upstanding posts 115 in the'plenum chamber 122. A second cover plate 220 extends inwardly from the nozzle 210.
The two concentric nozzles 110 and 210 incorporate the principles previously described in connection with the nozzle of FIG. 1. In operation, the concentric nozzles and 210 project concentric sprays into the atmosphere, but each spray has a trajectory position at a different angle with respect to horizontal. The spray device shown in FIG. 10 is especially useful for spraying large volumes of liquid by a single floating unit.
There has been described above in connection with FIGS. 1 to 10 several preferred spray units embodying the spray nozzle of the invention. In each spray unit, the pressure nozzle has an orifice which increases the dynamic pressure head relative to the static pressure head. A lateral first wall at one side of the orifice extends longitudinally along the liquid flow path from a point upstream to a point downstream of the orifice. The portion of the first wall downstream of, and exterior to, the orifice has a length at least the effective length of the orifice for traversing, and extending across the entire path of liquid flow from other orifice walls; the portion of the wall upstream of, and interior to, the orifice has a length sufficient to form a first unidirectional sheet of liquid which is laminar adjacent to the wall. The sheet is conducted from inside to outside of the orifice along the wall. A second sheet of liquid is similarly generated on an adjacent second wall, upstream of, and interior to, the orifice, and is conducted for intersection at the acute angle with the first sheet at a point outside the orifice. The depth of each liquid sheet so formed is thin relative to its breadth. The resulting stream, formed by the collision of the two thin liquid sheets is unstable and shatters into droplets as it is projected into the atmosphere. The intersection of the laminar sheets of liquid produces a stream that disrupts in a predictable manner into droplets of an optimum size and number, andwhich can be predictably varied by adjusting the size of the nozzle orifice. Stated another way, the surface of the orifice walls contacting the liquid have dimensions and are of a configuration sufficient to generate and maintain a unidirectional sheet of liquid on each wall from a point inside the orifice to a point of collision of the sheets prior to the end of one wall outside of the orifice thereby resulting in an emerging unstable stream which disrupts into droplets of predictable size as they are projected into the atmosphere. In the case of a circular, or arcuate, orifice the length of the wall upstream of, and interior to, the orifice will necessarily be somewhat smaller in length than the outside dimensioned length of the orifice since the shape configuration of the wall is the t ust um 0 n ..j
The advantages of the invention should be clear from the foregoing description. The pressure nozzle of the invention produces a spray having droplets of an optimum size and number without using rotating parts, as in a spinning nozzle, and by the novel arrangement of stationary walls at the nozzle orifice. The spray is substantially free from droplets of a size, for example of a size less than 30 microns, that will form a mist which will drift. The nozzle of the invention may be used in many different configurations. It may be circular or straight, and may be employed in many different spray units to meet the needs, circumstances and desiderata of many different situations as shown for instance in FIGS. 2A and B, 3, 5, 6, 9A to 9E, and 10.
In the drawing and specification, there has been set forth preferred embodiments of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only, and not for the purpose of limitation. Changes in form and proportion of parts, as well as substitution of equivalents are contemplated, as circumstances may suggest or render expedient, without departing from the spirit and scope of this invention, as further defined in the following claims:
1. A nozzle for spraying liquid under pressure into the atmosphere, and which is adapted to effect improved cooling, aeration, condensing, humidification, or stripping of dissolved or entrained gases, comprising in combination:
a wall member at the nozzle orifice for directing liquid under pressure into the atmosphere, said wall member extending between an inlet end and a discharge end,
means for supplying liquid under pressure along said wall member to form a first liquid sheet directed in a path substantially parallel to said wall member, and
means for conducting at least one other second sheet of liquid under pressure against said wall member that intersects said first sheet on the wall member between said inlet end and said discharge end at an acute angle, in amounts, at pressures, and over areas sufficient to form a liquid spray which which is substantially disrupted into droplets.
2. The nozzle of claim 1 in which the means for conducting said second sheet of liquid under pressure is at an acute angle offset from parallel with respect to said first sheet within the range of from about to about 80.
3. The nozzle of claim 1 further characterized by said last named means having an outlet member for directing said second sheet of liquid against said first named wall member, said outlet member spaced from said wall member, and means for adjusting the relative distance between said outlet member and said wall member.
4. A nozzle having an orifice for spraying liquid, and which is adapted to optimize the size and number of droplets produced thereby, comprising:
a first wall member at the nozzle orifice having an inlet end and a discharge end for generating and conducting a first sheet of liquid under pressure in a path from said inlet end toward said discharge end, and
a second wall member having an inlet end and a discharge end for generating a second sheet of liquid,
said second wall member spaced from and biangular,
with respect to said first wall member for conduct ing a second sheet of liquid under pressure against said first sheet of liquid at an angle that intersects said first sheet of liquid between said inlet end and a discharge end f aid s o mwa l membe at an acute angle, in amounts, at pressures, and over areas sufficient to form a liquid spray which .issub tant all t tz sq t T9P 5. The nozzle according to claim 4 further characterized in that said second wall is of an extent sufficient'for said second sheet to substantially traverse the entire path of said first sheet.
6. The nozzle of claim 5 further characterized by means for adjusting the space between said first and second wall members.
7. The nozzle of claim 5 wherein said first and second walls are offset from parallel within the range from about 10 to about 8. A nozzle having an orifice for spraying liquid, and which is adapted to improve the size and number of droplets produced thereby, comprising:
a wall member at the nozzle orifice for directing a stream of liquid under pressure into the atmosphere,
said wall member extending between an inlet end and a discharge end,
means for supplying liquid under pressure along said wall member to form a first sheet directed in a path substan-tially parallel to said wall member, and
means for conducting at least one other second sheet of liquid under pressure against said wall member at an acute angle that intersects said sheet on the wall member at a location between said inlet end and said discharge end for increasing the formation of droplets as the resultant stream of liquid is projected into the atmosphere.
9. The nozzle according to claim 8 in which said wall member extends from said inlet end located upstream ofsaid nozzle orifice to said discharge end located downstream from said nozzle orifice.
10. The nozzle according to claim 8 in which said outlet means conducts the second sheet at an angle offset from parallel about 10 to about 80 with respect to said first sheet on said wall member.
11. The nozzle according to claim 8 which further includes means for adjusting the cross-sectional dimension of the orifice.
12. A nozzle having an orifice for spraying liquid, and which is adapted to optimize the size and number of droplets produced thereby, comprising:
a wall member at the nozzle orifice for directing a stream of liquid under pressure into the atmosphere,
said wall member in the form of an inverted frustoconical surface extending between a fluid inlet end and a fluid discharge end,
means for supplying liquid under pressure along said surface of the wall member to form a first sheet directed in the path substantially parallel to said wall member, and
means having outlet means for conducting at least one second sheet of liquid under pressure against said wall member at an acute angle that intersects said first sheet on a said first wall member be tween said fluid inlet end and said discharge end sufficient to optimize the size and number of droplets in the liquid spray.
13. The nozzle according to claim 12 which further includes means for adjusting the distance between said outlet means and said wall'member.
14. The nozzle according to claim 12 in which said outlet means conducts said second sheet at an angle offset from parallel in the rnage from about 10 to about 80 with respect to said first sheet.
15. A nozzle for spraying liquid under pressure into the atmosphere comprising:
a circular nozzle orifice,
a wall member at said nozzle orifice for directing a stream of liquid under pressure into the atmosphere,
said wall member having the configuration of an inverted frusto-conical surface,
said wall member having a circular inlet end and a circular discharge end of greater diameter than said inlet end,
means for supplying liquid under pressure along said her beyond the orifice into the atmosphere, forming at least one other second-sheet of liquid under pressure upstream to the nozzle orifice, said first and second sheets of liquid thin relative to wall member to form a first liquid sheet directed in breadth, and
a P substantially P to Said Wall member, directing said second sheet at an acute angle that and intersects said first liquid sheet before said first outlet means for conductmg a Second l Sheet sheet leaves the wall member in order to form a under pressure i Y' member at f liquid spray which is substantially disrupted into acute angle that intersects said first sheet on said droplets wall member between said inlet and discharge ends thereof in order to form a stream of liquid that is ll 'lli y.Sli lpisfl.F EW Q "W- from parallel in the range from 10 to 80.
The nozzle according to claim 14 which further 22. The method of claim 20 which further comprises includes means for adjusting the distance between said 15 the stefiof adjusting the Size of the outle means and said wan f 23. Kn apparatus for spraying liquid comprising:
An appfilatus for Spraymg water from a water conduit means having at-least one intake opening in supplycompnsmgz communication for conducting liquid under presmeans for supplying water under pressure from the Sure,
" 21. The method of claim 20 in which said second sheet intersects said first sheet at an acute angle offset nozzle means having an orifice for discharging water into the atmosphere as a spray,
distributing chamber means for directing the water under pressure to nozzle means,
orifice means on said nozzle means for directing the water into the atmosphere, and
biangular wall members at said orifice means for disintegrating the water into droplets as it is projected into the atmosphere,
said biangular wall members including a first wall for producing a first sheet of water and a second wall member for producing a second sheet of water that plenum chamber means communicating with said conduit means for conducting the propelled liquid outwardly from said conduit means;
nozzle chamber means communicating with said plenum chamber means for projecting the liquid into the atmos-phere,
orifice means in said nozzle chamber means through which theliquid is projected into the atmosphere,
said orifice means having an opening for increasing the velocity pressure head relative to the static rTssure head; and
stationary wall members on opposite sides of said oriadapted to optimize thesize and i iifinTjefr'oftiropie ts,
fice for generating and impinging at least one liquid sheet against another liquid sheet. before one liquid sheet leaves one stationary wall member in order to disrupt the liquid into droplets as it is projected ntqct atmqrm ts- H 24. The method of claim 20 in which said liquid spray is substantially free from droplets that will form a mist which will drift.
25. The method of claim 20 in which said liquid spray is substantially free from droplets of a size less than microns.
26. The method of claim 20 in which the majority of droplets in said liquid spray are in a size range from 0.25 inch to about 0.75 inch.
intersects said first sheet before said first sheet leaves said first wall member.
18. The apparatus of claim 17 in which said biangular wall members are at an angle with respect to each other in the range from about 10 to about 80.
19. The apparatus of claim 17 further characterized by means for adjusting the distance between said wall members in order to vary the size of the orifice.
20. A method for spraying liquid, and which is