Spray Nozzle for High Viscosity Spray Applications with Uniform Spray Distribution

Abstract

A nozzle and spray dispenser for generating a uniform substantially flat fan spray pattern when spraying high viscosity fluids (i.e., oils, lotions, cleaning liquids, shear-thinning liquids and gels and similar Newtonian and non-Newtonian fluids having viscosities of 10-100 cP) is configured with an exit orifice 134 defining multiple lip segments 150A, 150B, 150C. Cup-shaped nozzle member 100 has a cylindrical side wall 102 surrounding a central longitudinal axis and has a circular closed end wall with at least one exit aperture passing through the end wall 112. At least one enhanced exit orifice structure is formed in an inner surface of the end wall, and includes two to five lip segments of selected width defining edges at the orifice 134, where each edge segment is defined at the distal edge of a separate and distinct interior wall segment 160A, 160B, 160C which has a selected wall convergence angle β.

Claims

1. A spray nozzle configured to generate a uniform flat fan spray along a transverse spray axis when spraying Newtonian or non-Newtonian viscous fluids, comprising: a shear nozzle member defined around a first central longitudinal spray axis and having a side wall enclosing an interior volume defining a fluid channel and having a proximal open lumen end opposing a closed distal end wall; said nozzle member including at least a first shear nozzle exit orifice passing through said distal end wall, said first shear nozzle exit orifice being coaxially aligned with said first central longitudinal spray axis and providing fluid communication between said nozzle member's interior fluid channel and the ambient space beyond the distal end wall; said nozzle member's exit orifice being elongated or substantially rectangular with the orifice's larger internal diameter dimension being aligned with a transverse “V-shaped groove” defining a distal surface exit angle a and aligned with the transverse spray axis which intersects the central longitudinal spray axis; said nozzle member's fluid channel terminating distally in an interior surface of said distal end wall including a plurality of converging wall segments which terminate in said shear nozzle exit orifice to define a plurality of wall edge or lip segments; wherein each converging wall segment defines an interior fluid channel surface which intersects the shear nozzle exit orifice at a selected convergence angle β; and wherein each converging wall segment's distal edge defines an orifice lip segment with a selected lip width or transverse length.

2. The spray nozzle of claim 1, wherein said plurality of converging wall segments comprise a first converging wall segment and a second converging wall segment; wherein said first converging wall segment terminates in said shear nozzle exit orifice to define a first wall edge or lip segment and defines an interior fluid channel surface which intersects the shear nozzle exit orifice at a first selected convergence angle β1 and said first converging wall segment's distal edge defines a first orifice lip segment with a first selected lip width or transverse length F.sub.1W; and wherein said second converging wall segment terminates in said shear nozzle exit orifice to define a second wall edge or lip segment and defines another interior fluid channel surface which intersects the shear nozzle exit orifice at a second selected convergence angle β2 which is unequal to first selected convergence angle β1, and wherein said second converging wall segment's distal edge defines a second orifice lip segment with a second selected lip width or transverse length F.sub.2W which may be equal to or unequal to said first selected lip width F.sub.1W.

3. The spray nozzle of claim 2, wherein said plurality of converging wall segments each define an interior fluid channel surface which intersects the shear nozzle exit orifice at a selected convergence angle β, said selected convergence angle β being selected to be an angle which is at least 20 degrees and not greater than 180 degrees.

4. The spray nozzle of claim 3, wherein said plurality of converging wall segments additionally include a third converging wall segment defined proximate said second converging wall segment; wherein said third converging wall segment terminates in said shear nozzle exit orifice to define a third wall edge or lip segment and defines another interior fluid channel surface which intersects the shear nozzle exit orifice at a third selected convergence angle β3 which is may be equal to or unequal to said first selected convergence angle β1, and wherein said third converging wall segment's distal edge defines a third exit orifice lip segment with a third selected lip width or transverse length F.sub.3W which may be equal to or unequal to said first selected lip width F.sub.1W.

5. The spray nozzle of claim 3, wherein said first and third lips define outer lip segments and said second lip defines a central lip segment between and contiguously abutting said first and third lip segments' and wherein said second lip width is selected to comprise 10%-70% of the transverse width, F.sub.w of the exit orifice.

6. The spray nozzle of claim 4, further comprising a fourth converging wall segment defined proximate said third converging wall segment wherein said fourth converging wall segment terminates in said shear nozzle exit orifice to define a fourth wall edge or lip segment and defines another interior fluid channel surface which intersects the shear nozzle exit orifice at a fourth selected convergence angle β4 which may be equal to or unequal to said first selected convergence angle β1, and wherein said fourth converging wall segment's distal edge defines a fourth exit orifice lip segment with a fourth selected lip width or transverse length F.sub.4W which may be equal to or unequal to said first selected lip width F.sub.1W.

7. The spray nozzle of claim 6, further comprising a fifth converging wall segment defined proximate said fourth converging wall segment wherein said fifth converging wall segment terminates in said shear nozzle exit orifice to define a fifth wall edge or lip segment and defines another interior fluid channel surface which intersects the shear nozzle exit orifice at a fifth selected convergence angle β5 which may be equal to or unequal to said first selected convergence angle β1, and wherein said fifth converging wall segment's distal edge defines a fifth exit orifice lip segment with a fifth selected lip width or transverse length F.sub.5W which may be equal to or unequal to said first selected lip width F.sub.1W.

8. The spray nozzle of claim 1, wherein said exit angle α is selected to be at least 10 degrees and no greater than 90 degrees.

9. The spray nozzle of claim 1, wherein said feed inlet lumen has a substantially rectangular cross section with lumen area defined by parallel sidewalls separated by a feed width Fw and having a sidewall height of Fh at said inlet's proximal open end; and wherein said lip segment widths combine to define said exit orifice width which is equal to feed width Fw.

10. The spray nozzle of claim 1, wherein said feed inlet lumen has a substantially circular or elliptical cross section and a feed width Fw and wherein said lip segment widths combine to define said exit orifice width which is equal to feed width Fw.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The foregoing, and additional objects, features, and advantages of the present invention will be further understood from the following detailed description of preferred embodiments thereof, taken with the following drawings, in which:

[0023] FIG. 1A illustrates the spray head of a manual-trigger spray applicator in accordance with the prior art;

[0024] FIG. 1B illustrates typical features of a prior art aerosol spray actuator having a traditional flat fan spray shear nozzle;

[0025] FIGS. 1C-1F illustrate typical features of a prior art flat fan spray shear nozzle member's internal geometry and exit orifice geometry;

[0026] FIG. 2 is a shaded perspective view, in elevation, illustrating a viscous fluid flat fan spray generating nozzle member's distal end wall and exit aperture which defines an enhanced multi-lip flat fan spray generating structure comprising first, second and third exit orifice lips or lip segments, in accordance with the present invention;

[0027] FIG. 3A is rear or proximal open end view, in elevation of a cup-shaped viscous fluid flat fan spray generating nozzle member with a substantially cylindrical sidewall surrounding a central longitudinal spray axis which intersects a transverse spray fan axis; the nozzle member's cylindrical sidewall terminates distally in a substantially circular distal end wall having an interior surface with a central exit aperture, and the interior surface of the distal wall includes is an enhanced multi-lip flat fan spray generating structure which includes three separate contiguous regions defined by converging fluid feed channel wall segments converging at selected interior wall convergence angles to define the three lips or lip segments of FIG. 2, in accordance with the present invention;

[0028] FIG. 3B is a side view, in elevation, illustrating the side cross section of the cup-shaped viscous fluid flat fan spray generating nozzle member of FIG. 3A, in accordance with the present invention;

[0029] FIG. 3C is a distal end view, in elevation illustrating the distal end surface and exit orifice of the cup-shaped viscous fluid flat fan spray generating nozzle member of FIG. 3A, in accordance with the present invention;

[0030] FIG. 4 is a diagram illustrating the geometry of the features of the nozzle member of FIGS. 2-3C as imagined from a side view like FIG. 3B showing the outer fluid feed channel wall segments' convergence angle β1 and the central fluid feed channel wall segment convergence angle β2 symmetrically configured about the nozzle member's central spray axis, in accordance with the present invention;

[0031] FIG. 5 is a detailed or magnified diagram illustrating the geometry of the features of the nozzle member of FIGS. 2-3C, as imagined from a distal end view like FIG. 3C showing the exit orifice's central placement at the intersection of the nozzle member's central spray axis and transverse flat fan axis and showing, in hidden line, the rectangular feed channel's converging wall segments, in accordance with the present invention;

[0032] FIG. 6 is a shaded perspective cut-away view, in elevation, of the nozzle member of FIGS. 2-3C illustrating the rectangular feed lumen and exit aperture, including the first, second and third converging wall segments terminating in first, second and third exit orifice lips or lip segments, in accordance with the present invention; and

[0033] FIG. 7 is a shaded perspective cut-away view, in elevation, of an alternative nozzle member illustrating a tubular or circular sectioned feed lumen and central exit aperture (shown split along the central axis), showing first and second converging wall segments terminating in first and second exit orifice lips or lip segments, in accordance with the present invention.

DESCRIPTION OF THE INVENTION

[0034] Referring now to the Figures, wherein common elements are identified by the same numbers, FIG. 1A illustrates a typical manually-operated trigger pump 10 secured to a container 12 of fluid to be dispensed, wherein the pump incorporates a trigger 14 activated by an operator to dispense fluid 16 through a nozzle 18. Such dispensers are commonly used, for example, to dispense a fluid from the container in a defined spray pattern or as a stream. Adjustable spray patterns may be provided so the user may select a stream or one of a variety of sprayed fluid droplets. A typical nozzle 18 consists of tubular conduit that receives fluid from the pump and directs it into a spray head portion, where the fluid travels through channels and is ejected from orifice, or aperture 28. Such devices are constructed as a one-piece molded plastic “cap” with channels that line up with the pump outlet to produce the desired stream or spray of a variety of fluids at pressures generally in the range of 30 to 40 PSI, if spraying a fluid which is not significantly more viscous than water.

[0035] FIGS. 1B and 1C illustrate a typical commercial aerosol dispenser 28 configured with a traditional flat fan spray nozzle member configured as a cup shaped member 30. These standard cup-shaped nozzle members 30 have an interior surface which abuts and seals against a face seal on a planar circular surface of distally projecting sealing post 36 and is arranged so that the flow of product fluid 35 flows into and through an annular lumen into the fluid feed or input channel 33 and then flows distally into the central converging region 35. The fluid product flows distally or downstream and leaves the converging region 35 through an exit orifice 34 which is typically concentric to the central axis of the sealing post 36. For viscous liquid products, the fluid product spray 38 issuing from or generated by the standard nozzle assembly sprays a non-uniform pattern of liquid droplets as described above. These viscosity dependent problems were analyzed by the applicants, who have discovered that parts of the standard nozzle assemblies of the spray dispensers 10, 28 can be used for spraying viscous products, but only if a newly developed nozzle configuration is also used.

[0036] To overcome the problems found in prior art sprayers of FIGS. 1A-1F, in accordance with the present invention, a new nozzle assembly is configured for use with the spray head and sealing post structure of standard nozzle assemblies, but discards the flawed performance of the standard cup-shaped nozzle member (e.g., 30). Thus, the present invention is directed to a new nozzle configuration, illustrated in FIGS. 2-7, which permits significantly improved control of the subject high viscosity fluids (i.e., oils, sunscreen lotions, other lotions, cleaning liquids, shear-thinning liquids and gels and similar Newtonian and non-Newtonian fluids having viscosities of 10-100 cP) and permits the configuration of a flat fan spray generating nozzle which will generate substantially uniform spray density over the entire width of the spray fan.

[0037] Referring initially to FIG. 2, and comparing this to prior art FIG. 1F, new exit orifice 134 has a crenellated appearance with plural distinct, discontinuous shear inducing edge segments or lips 150A, 150B, 150C, defining the exit orifice 134 with multiple lip surfaces instead of a single continuous lip edge (e.g., FIG. 1F's lips L.sub.1 or L.sub.2). Applicants' new multi-lip configuration enables significantly enhanced control of spray volume distribution, and is especially well suited for controlling the distribution of liquid volume across the spray fan for high viscosity liquids.

[0038] Referring next to three views of a cup-shaped viscous fluid flat fan spray generating nozzle member 100 configured for use with for spray-type dispensers (e.g., as shown in FIG. 1A or 1B) subject viscous fluid product flows into and through a rectangular feed channel 110 having a lumen height Fh and a lumen width Fw. Flow in the feed lumen 110 is directed distally or downstream to exit orifice 134 by planar, parallel side walls and converging top and bottom walls. In the prior art nozzles (e.g., 30) the exit orifice (e.g., 34) is characterized by an aperture defined between opposing single continuous lips (e.g., L.sub.1, L.sub.2) each defined at the distal end of a top or bottom wall segment having one angle or convergence β1 (Beta, best seen in FIGS. 1D and 1E). While this invention is described in these exemplary embodiments as used with a rectangular feed lumen 110, the multi lip exit orifice of the present invention 134 can also be used with a circular or elliptical cross section feed lumen (as illustrated in FIG. 7, to be described further below).

[0039] Cup-shaped viscous fluid flat fan spray generating nozzle member 100 has a substantially cylindrical sidewall 102 surrounding a central longitudinal spray axis 120 which intersects a transverse spray fan axis 220. The cup-shaped viscous fluid flat fan spray generating nozzle member's cylindrical sidewall 102 has an open proximal end 104 defining the upstream end of an interior volume 106. Nozzle member sidewall 102 terminates distally in a substantially circular distal end wall 112 having an interior surface 114 and an exterior, or distal, surface 116 with a central outlet or exit aperture 134 which provides fluid communication between the interior 106 and exterior of the cup shaped nozzle member 100. There may be more than one exit orifice in a nozzle assembly or for use with a dispenser, but for purposes of describing the nozzle geometry of the present invention, the exemplary nozzle member 100 including at least a first shear nozzle exit orifice 134 passing through distal end wall 112, and that exit orifice is coaxially aligned with first central longitudinal spray axis 120 and provides fluid communication between said nozzle member's interior fluid channel 106 and the ambient space beyond the distal end wall 116. As best seen in FIG. 5, exit orifice 134 is elongated or substantially rectangular with the orifice's larger internal diameter dimension being aligned with the transverse “V-shaped groove” defining distal surface exit angle a and aligned with the transverse spray axis 220 which intersects the central longitudinal spray axis 120.

[0040] Defined in the interior surface 114 of the distal wall 112 is an enhanced multi-lip flat fan spray generating structure which includes plural (at least first and second, but, in the illustrated embodiment, first, second and third) distinct, contiguous fluid feed channel wall segments converging at plural (e.g., first and second interior wall convergence angles (β1, β2, each selected from the range of 20 to 180 degrees) to define plural exit orifice lips or lip segments (e.g., 150A, 150B, 150C. Each exit orifice lip has a selected lip edge length or transverse width to define a portion of the exit orifice 134 in the end wall 112.

[0041] In the configuration seen in FIGS. 3A-5, internal threads (not shown) may optionally be included in an internal surface of sidewall 102 at the inlet side or open proximal end 104 the nozzle member 100. The internal threads (if included) are configured to engage with external threads 53 located on the distal end of a discharge of nozzle body 10. Various other mechanical methods of connecting the nozzle member 100 to a dispenser may be used. For example, an alternative method of connecting the nozzle member may be a snap fit type connection.

[0042] The distal or exit side or surface 116 of distal wall 112 has distally projecting boss 118 with transverse “V-shaped” groove 119 cut therethrough which intersects the interior forming the elongated exit orifice 134. Transverse “V-shaped” groove 119 defines a pair of angled inside surfaces symmetrically arranged about and spaced from transverse spray axis 220, and the groove's inside surfaces define an exit angle α (alpha), which is (in the illustrated example) 30 degrees. During a dispensing cycle of a spray delivery system using nozzle member 100 it is the transition of the internal feed lumen 110 the interior surface features defining exit orifice 134 that causes the convergence of the fluid streamlines toward the elongated orifice 134 at high stream velocities when the fluid is forced through the spray nozzle member 100. The multi-lipped geometry of exit orifice 134 forces the fluid streamlines to form a plurality or flat liquid sheets oriented parallel to transverse axis 220 upon exiting or being dispensed from the confines of the spray nozzle member 100. External to the spray nozzle member 100 the fluid flowing over each lip segment (e.g., 150A, 150B and 150C) form ligaments and thereafter droplets which disperse or disintegrate into a fan shaped atomized spray pattern (not shown) aligned along transverse axis 220.

[0043] Generally, this fan spray pattern (not shown) consists of dispersed droplets of fluid arranged such that a transverse cross-section of the fan spray pattern would be elongated, elliptical, or oblong in shape. The dispersed droplets of fluid may be finely dispersed, such as an atomized spray, or even more coarsely dispersed representing larger droplets of fluid. When this fan spray pattern contacts a surface intended to be coated with the fluid, a substantially uniform coating of fluid is produced having a substantially linear elongated shape.

[0044] FIGS. 3C and 6 depict the “V-shaped” groove 119 on the exterior surface 116 of nozzle member 100. As noted above, “V-shaped” groove 119 has an angle α (alpha), which represents the average included angle of the groove measured along the major diameter of the elongated orifice 134 which is parallel with transverse spray axis 220. As defined herein, the angle a will of necessity be some value between about 0° and 180°, with the 0° representing a slot with spaced parallel sides and 180° representing no groove 119 at the exit orifice on the distal or exit side 116. The angle α is preferably, is from about 20° to about 90°; more preferably, from about 30° to about 50°; and most preferably about 30°. It has been found that a triangular prismatic or “V-shaped” groove 119 and a converging 114 or hemispherical 314 interior surface in fluid communication with a liquid inlet lumen 110 work well to produce the liquid sheet which generates the desired flat fan spray pattern.

[0045] The multi-lip configuration of nozzle member 100 enables significantly enhanced control of spray volume distribution, and is especially well suited for controlling the distribution of liquid volume across the spray fan for high viscosity liquids. In an exemplary embodiment, fluid flow enters through rectangular feed channel or lumen 110, and the fluid is forced or directed distally or downstream to exit orifice 134 between the planar, parallel side walls and converging top and bottom walls of feed lumen 110. At distal end wall 112, exit orifice 134 is bounded by multiple separate discontinuous lips or edges (e.g., 150A, 150B, 150C). These separate or discontinuous lips are each formed at the distal end of separate and distinct interior wall segments (160A, 160B, 160C) having selected convergence angles β, so in the example illustrated in FIGS. 2-6, outlet orifice 134 has outer or first and third lip segments (150A, 150C) defined by first and third separate interior wall segments having a first selected interior wall convergence angle β1 (selected to be, e.g., 100-180 degrees, for interior wall segments 160A and 160C, which terminate distally at the orifice resulting in lips 150A and 150C) while a second, central lip segment 150B is defined by a second separate interior wall segment 160B having a second selected interior wall convergence angle β2 (selected to be, e.g., 20-100 degrees) which terminates distally at the orifice to form the center lip 150B. Note that convergence angles for the outer lips 150A and 150C are equal in this example, but could be different as well. In that case the three wall segments 160A, 160B, 160C would define three convergence angles (β1, β2 and β3).

[0046] The exemplary embodiment here described is for three lips or lip segments 150A, 150B, 150C, but the nozzle structure and method of the present invention can be extended to five or more lips, when there is a need to control distribution and spray angle with greater resolution. A nozzle with five lip segments could include five (5) separate and distinct selected interior wall convergence angles (β1-β5) each selected from the range of 20 to 180 degrees.

[0047] In accordance with the present invention, each lip segment defines an edge having its own lateral extent or width. In existing designs (e.g., prior art nozzle 30), each single lip (e.g., L.sub.1 or L.sub.2) has a width equal to the width of the feed lumen, Fw (as shown in FIGS. 1C, 1E, 1F). In the present invention as illustrated in FIGS. 2-7, each lip segment (e.g., 150A, 150B, 150C) has its own segment edge length (which are designated Fw1, Fw2, Fw3, (best seen in FIGS. 5 and 6), as if each segment were considered to comprise its own feed lumen). The transverse length defined by each lip segment (e.g., Fw1, Fw2 or Fw3) is chosen to enable a uniform spray distribution for the entire exit orifice 134. In general, applicants' have found that for the subject high viscosity fluids (i.e., oils, sunscreen lotions, other lotions, cleaning liquids, shear-thinning liquids and gels and similar fluids having viscosities of 10-100 cP) a surprisingly uniform spray fan (not shown) can be generated with narrower or shorter outer lips (e.g., 150A and 150C) and a wider or longer central lip (e.g., 150B), and with the central lip being 150B defined with an edge that is more distally oriented (i.e., closer to external wall surface of distally projecting boss 118) with a smaller interior wall convergence angle β than the outer lips (as best seen in FIG. 2). In one prototype, the transverse edge length of the central lip (150B) was selected to be 40%-60% of the total feed width Fw and the transverse edge lengths of outer lips (150A and 150C) were 20-30% Fw, and this nozzle configuration was found to provide a significantly more uniform coating of the liquid spray. This prototype was one example having the outer lip segments (150A and 150C) defined with equal lengths, but those outer lip segments could be unequal and produce excellent spray results.

[0048] In operation, for the example nozzle described above, outer lips 150A and 150C have a high convergence angle (e.g., β1=150 degrees, see FIG. 4). This results in a larger spray angle on intersection, however since outer lips 150A and 150C have smaller widths compared to lip 150B, lesser volume flows past the edges of lips 150A and 150C. The center lip (150B) preferably has the largest width or edge length Fw2 and the smallest convergence angle β2, resulting in a smaller fan and more volume in the center of the spray. The spray from nozzle member 100 can be thought of as a superposition of three distinct spray fans, and the superposition of the three spray fans from the three lip segments results in a substantially more uniform volume distribution over the spray fan, when compared with prior art nozzle (e.g., 30).

[0049] More generally, the multi-lip design of the present invention is now believed to provide several effective embodiments for flat fan spray nozzles which are especially well suited for spraying viscous fluids uniformly into spray fan pattern. The preferred embodiments comprise two to five lip segments (e.g., 150A, 150B, 150C), each having a selected edge length or width (e.g., Fw1, Fw2, Fw3) and interior wall convergence angle β. By controlling lip width and convergence angle, liquid streamlines intersect at varying angles resulting in a uniform spray distribution and so the nozzles of the present invention can provide a much more even coating over a surface when spraying the subject high viscosity fluids (i.e., oils, sunscreen lotions, other lotions, cleaning liquids, shear-thinning liquids and gels and similar Newtonian and non-Newtonian fluids having viscosities of 10-100 cP).

[0050] Spray or exit orifice 134 is defined by first and second crenellated or discontinuous edges having symmetrically arrayed and aligned lip segments (e.g., 150A, 150B, 150C), as shown in FIGS. 3A, and 4-6. In the illustrated prototype, each lip segment is symmetrically aligned with a mirror image lip segment, where both are equally spaced from transverse axis 220.

[0051] As noted above, alternative embodiments are envisioned. For example, FIG. 7 illustrates the internal details for a cut away of a nozzle member, 300, where the feed channel is not rectangular, but is instead substantially circular. The interior surface 314 defined in distal end wall 312 is dome shaped, that is, resembling or shaped like a substantially hemispherical vault or in the form of a portion of a substantially spherical shape. The interior surface 314 a hemispherical diameter that is substantially equal to the diameter of fluid feed channel inlet lumen 310, and outlet orifice 334 is defined by multiple lips (e.g., 350A and 350B) to provide the same advantages described with regard to nozzle member 100, above.

[0052] Having described preferred embodiments of new and improved nozzle configurations and methods for generating uniform sprays of viscous fluids, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as set forth in the appended claims.