Patent Application
20170065990
Field of the Invention
The present invention relates, in general, to spray nozzles configured for use when spraying consumer goods such as air fresheners, cleaning fluids, personal care products and the like. More particularly, this invention relates to a fluidic nozzle assembly for use with low-pressure, trigger spray or “product only” (meaning propellant-less) applicators or nozzles for pressurized aerosols (especially Bag-On-Valve and Compressed Gas packaged products).
Discussion of the Prior Art
Generally, a trigger dispenser for spraying consumer goods is a relatively low-cost pump device for delivering liquids from a container. The dispenser is held in the hand of an operator and has a trigger that is operable by squeezing or pulling the fingers of the hand to pump liquid from the container and through a spray head incorporating a nozzle at the front of the dispenser.
Such manually-operated dispensers may have a variety of features that have become common and well known in the industry. For example, a prior art dispenser may incorporate a dedicated spray head having a nozzle that produces a defined spray pattern for the liquid as it is dispensed or issued from the nozzle. It is also known to provide nozzles having adjustable spray patterns so that with a single dispenser the user may select a spray pattern that is in the form of either a stream or a substantially circular or conical spray of liquid droplets.
Many substances are currently sold and marketed as consumer goods in containers with such trigger-operated spray heads, as shown in
Sprayer heads recently have been introduced into the marketplace which have battery operated pumps in which one has to only press the trigger once to initiate a pumping action that continues until pressure is released on the trigger. These typically operate at lower pressures in the range of 5-15 psi. They also suffer from the same deficiencies as noted for manual pumps; plus, they generally have even less variety in or control of the spray patterns that can be generated due to their lower operating pressures.
Aerosol applications are also common and now use Bag-On-Valve (“BOV”) and compressed gas methods to develop higher operating pressures, in the range of, e.g., 50-140 psi rather than the previously-used costly and less environmentally friendly propellants. These packaging methods are desired because they can produce higher operating pressures compared to the other delivery methods, as mentioned above.
The nozzles for typical commercial dispensers are typically of the one-piece molded “cap” variety, having channels producing either spray or stream patterns when the appropriate channel is lined up with a feed channel coming out of a sprayer assembly. These prior art nozzles are traditionally referred to as “swirl cup” nozzles inasmuch as the spray they generate is generally “swirled” within the nozzle assembly to form a spray (as opposed to a stream) having droplets of varying sizes and velocities scattered across a wide angle. Traditional swirl nozzles consist of two or more input channels positioned tangentially to an interaction region, or at an angle relative to the walls of the interaction region (see, e.g.,
The problems with the prior art nozzle assemblies of
As described in the above-mentioned commonly owned U.S. Pat. No. 7,354,008 to Hester et al, a spray head nozzle for the above-described dispensers may incorporate a fluidic device that can, without any moving parts, yield any of a wide variety of spray patterns having a desired droplet size and distribution. Such devices include fluidic circuits having liquid flow channels that produce desirable flow phenomena, and such circuits are described in numerous patents. The Hester patent describes fluid circuits for low pressure trigger spray devices.
Swirl nozzles are used in numerous applications. The primary function is generating an atomized spray with a preferred droplet size distribution. For many applications, it is preferred that the sprayed droplet Volumetric Median Diameter (VMD or DV50) and domain of the distribution be as small as possible. It is also desired to minimize the operating pressure required to generate a preferred level of atomization. There is a need, therefore, for a cost effective substitute for the traditional swirl cup, which will reliably generate droplets of a selected small size so as to avoid the splattering and other disadvantages of large droplet creation by traditional swirl cups in relatively high pressure applications such as hand operated pumps that can generate pressures in the range of 30-40 psi, or for “BOV” and compressed gas devices that develop higher operating pressures, in the range of, e.g., 50-140 psi.
The applicants have studied the prior art swirl cup nozzles (e.g., as illustrated in
After identifying the problems causing this poor misting performance of the prior art swirl cup nozzles, the applicants herein developed a new nozzle assembly which avoids these problems while maximizing the creation and preservation of small droplets which are issued at a very high angular velocity.
The High Efficiency Mechanical Break Up (“HE-MBU”) nozzle assembly of the present invention includes two unique features which differ significantly when compared to traditional swirl nozzle geometry of the prior art. These newly developed features reduce internal shear losses and improve and maintain resultant spray atomization. Improved spray atomization is characterized by increasing angular velocity “ω” for a given input pressure, resulting in generation and maintenance of smaller droplets. In addition to ω, a number of other factors influence the atomization or VMD of the spray output, such as coagulation. Coagulation is a phenomenon where small drops collide and recombine downstream of the nozzle exit, and by recombining, form larger drops than ones generated at the nozzle exit. As a result, VMD increases as the distance of the measurement location from the nozzle exit increases. This phenomena is undesirable when the application calls for a fine mist (e.g., as used in many hair care products).
Hence, a first embodiment of the present invention includes two principal improvements over traditional swirl nozzle of the prior art, namely: (1) a swirled spray with significantly increased rotating or angular velocity ω, resulting in smaller droplet size, and (2) a distally projecting swirling spray with reduced coagulation, further reducing & maintaining smaller droplet size.
Briefly, then, in a preferred form of the invention, a nozzle for a spray dispenser is configured to generate a swirled output spray pattern with improved rotating or angular velocity ω, resulting in smaller sprayed droplet size. A cup-shaped nozzle body has a cylindrical side wall surrounding a central longitudinal axis and has a circular closed end wall with at least one exit aperture passing through the end wall. At least one enhanced swirl inducing mist generating structure is formed in an inner surface of the end wall, with the fluidic circuit including a pair of opposed inwardly tapered offset power nozzle chambers terminating in an interaction region surrounding the exit aperture. The power nozzle chambers are offset in opposite directions with respect to the transverse axis of the exit aperture, whereby fluid under pressure introduced into the fluidic chamber accelerates along the power nozzle chambers into the interaction region to generate a swirling fluid vortex which exits the exit aperture as a swirling spray. Each power nozzle chamber is defined by a continuous, smooth, curved wall and has a selected depth Pd defined by the height of the wall, with each power nozzle's sidewalls tapering generally inwardly from an enlarged region at the inlet, narrowing toward the interaction region to accelerate fluid flow. The power nozzle chambers each have a minimum exit width Pw at their intersection with the interaction region, and in selected embodiments have an aspect ratio equal to or less than 1 at the intersection.
More particularly, in one embodiment of the invention, a cup-shaped nozzle for spray-type dispensers has a substantially cylindrical sidewall surrounding a central axis, and a substantially circular distal end wall having an interior surface and an exterior, or distal, surface with a central outlet, or exit aperture, which provides fluid communication between the interior and exterior of the cup. Defined in the interior surface of the distal wall is an enhanced swirl inducing mist generating structure which includes first and second opposing but offset power nozzles, each providing fluid communication to and terminating in a central interaction or swirl vortex generating chamber in the end wall and surrounding the exit aperture. Each power nozzle chamber defines a tapering channel or lumen of selected depth but narrowing width which terminates in a power nozzle outlet region or opening having a selected power nozzle width (Pw) at its intersection with the interaction chamber.
A first one of the power nozzles has an inlet which is defined in the interior surface of the distal, or end, wall proximate the cylindrical sidewall so that pressurized inlet fluid flows into the interior of the cup and distally along the sidewall to enter the first power nozzle inlet. The fluid enters and accelerates along the tapered lumen of first power nozzle to a nozzle outlet where the fluid enters one side of the interaction chamber. A second one of the power nozzles is similar to the first and also receives at its inlet pressurized fluid which is flowing distally along the interior of the cup and along its sidewall. The inlet fluid enters and accelerates along the tapered lumen of second power nozzle to the nozzle outlet, where it enters the opposite side of the interaction chamber.
The interaction or swirl region is defined in the interaction chamber between the opposing but offset power nozzle outlets and has a substantially circular section having a cylindrical sidewall aligned with the nozzle central axis and coaxially aligned with the central exit aperture, or orifice, which provides fluid communication between the interaction chamber and the exterior of the cup so that fluid product spray is directed distally or out along that central axis.
The input channels or power nozzles are elongated, extending from the region of the nozzle sidewall along respective axes toward the interaction region and varying in width Pw, tapering to a narrow exit region at the interaction region and having the selected depth Pd, The axes of the power nozzles are generally opposed, on opposite sides of the circular interaction chamber, and are offset in the same angular direction from the central exit orifice to inject pressurized fluid into the interaction region at another selected inflow angle relative to the central axis and the walls of the interaction region. The interaction region is preferably circular with a diameter which is in the range of 1.5 to 4 times the power nozzle outlet exit width Pw. The interaction chamber preferably has the same depth as each power nozzle, preferably has a face seal and preferably is arranged so that the fluid flows from the power nozzles and enters the interaction region tangentially, with a higher tangential velocity Uθ than the fluid entering the nozzle, thereby setting up a vortex with radius r and a higher angular velocity ω=Uθ/r. The rapidly spinning or swirling vortex then issues from interaction region through the exit aperture which in one embodiment is aligned with the central axis of the nozzle cup. This configuration causes mechanical breakup and rapidly swirling fluid droplets that are generated in the swirl chamber to accelerate into a highly rotational flow which sprays or issues from the exit orifice as very small droplets which are swirling and thus less likely to coagulate or recombine into larger droplets.
In an alternative embodiment developed to provide further improved atomization efficiency of the applicant's HE-MBU nozzle prototypes, angular velocity w was also found to vary significantly and in sometimes surprising ways by varying power nozzle offset ratio “OR”. The offset ratio “OR” is defined as Pw/IRd where outlet width (“Pw”) is preferably about one third of the swirl chamber or interaction region's diameter (“IRd”). As described above, reducing the HE-MBU chamber depths was found to reduce flow rate & improve the atomization of newer prototypes of the High Efficiency Mechanical Break Up (“HE-MBU”) of the present invention. Coincidently, as the power nozzle aspect ratio was reduced, the depth of the circuit was reduced. The early prototypes showed modest gains in atomization which were thought to be attributable to simply reducing the circuit depth, not the power nozzle aspect ratio. Significant additional gains were realized after experimenting with power nozzle offset ratios. Therefore, optimizing the offset ratio is now believed to be the best mechanism for enhancing the efficiency with which a mechanical break up nozzle atomizes fluid.
In accordance with the preferred method of the present invention, a High Efficiency Mechanical Break Up (“HE-MBU”) nozzle assembly includes an enhanced swirl inducing mist generating structure having first and second opposing, offset power nozzle channels each having an outlet width (“Pw”) which is preferably about one third of the swirl chamber or interaction region's diameter (“IRd”). The offset ratio “OR” is defined as Pw/IRd. Applicants have determined, through experiments and testing of prototypes that the optimal value of the offset ratio OR is 0.37 (having tested values ranging from 0.30 to 0.50). The optimal angle of attack was found to be substantially tangent to the adjacent segment of circumferential wall of the interaction region, and the optimal depth was found to be a depth which is as small as possible (limited by boundary layer effects which, at depths which are too small out weight the gains from reduced volume of the features) in the enhanced swirl inducing mist generating structure. For example, at the scale of a particular commercial air care fluid product nozzle being developed and evaluated, applicants have selected a depth of 0.20 mm. In this embodiment, the swirl chamber depth is the same depth as the power nozzles to minimize volume. Alternative embodiments are also contemplated. In the early prototype embodiments, all of the power nozzle channel and swirl chamber depths were selected to be the same, meaning the power nozzles and swirl chambers are all configured as fluid channels having single selected depth (e.g., 0.20 mm). An alternative embodiment would include a varying depth, providing a tapered or converging floor of the channels in the enhanced swirl inducing mist generating structure. Instead of having a constant depth for the power nozzle chambers and the interaction region or swirl chamber, having the depth of the power nozzles taper at a selected taper angle (becoming shallower in the direction of flow) to provide another swirl inducing mist generating structure which is believed likely to further improve atomization efficiency. The nozzles of the present invention can also have more than one enhanced swirl inducing mist generating structure in a single sprayer, meaning more than one (e.g., two or more) of the outlet orifices can be configured to generate simultaneous distally projecting sprays which each swirl a selected angular orientation (e.g., the same or opposing orientations), depending on the intended spray application.
With all of the foregoing embodiments, it is an object of the present invention to provide a cost effective substitute for traditional swirl cup dispenser assemblies which will reliably generate a swirling spray of droplets of a selected small size, preferably with a droplet diameter of 60-80 μM or less, but larger than 10 μM, where the swirling spray is generated in a manner which makes droplet recombination less likely so that the large recombined droplet creation of traditional swirl cups that produces undesirable spray effects, such as splattering is mitigated.
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:
Referring now to the Figures, wherein common elements are identified by the same numbers,
To overcome the problems found in prior art sprayers of
The fluidic nozzle assembly of the present invention incorporates the spray head and sealing post structure of the standard nozzle assembly, but discards the flawed performance of the standard swirl cup (e.g., 30). Thus, the present invention is directed to a new High-Efficiency Mechanical Break-Up (“HE-MBU”) nozzle assembly, illustrated in
In the first form of the invention illustrated in
As illustrated in the bottom plan view of
Each of the power nozzle outlet regions has a relatively narrow selected power nozzle exit width Pw at its intersection with the interaction chamber, with the generally radial axes of the power nozzles 80 and 82 being offset in the same direction from the central axis 64 of the nozzle 60. This offset causes the fluid flowing in the power nozzles to enter the interaction chamber 84 at desired angles, preferably substantially tangentially, to produce a swirl vortex in the interaction chamber which then flows out of the nozzle outlet 74 through the end wall 68. In the illustrations of
In accordance with the preferred method of the present invention, each High Efficiency Mechanical Break Up (“HE-MBU”) nozzle member (e.g., 60) includes an enhanced swirl inducing mist generating structure defined in a surface (e.g., 70) with first and second opposing, offset power nozzle channels (e.g., 86, 88) each having an outlet width (“Pw”) which is preferably about one third of the swirl chamber or interaction region's diameter “IRd” (or twice the radius IRφ, as best seen in
Alternative embodiments are also contemplated. In the embodiment of
Surrounding the bottom edge of the cup-shaped nozzle 60 is a flange 104 which provides a connection interface with a dispenser spray head in known manner, as by engaging a corresponding shoulder on the interior surface of the spray head outlet (as best seen in
In operation, a pressurized inlet fluid or fluid product, indicated by arrows 120, flows from a suitable dispenser spray head into the interior 76 of the nozzle 60, toward and into the lumens of power nozzles 86 and 88 formed and defined in the interior surface of the distal wall 68. The pressurized inlet fluid flows distally along an annular channel defined by the interior surface 112 of the cylindrical sidewall 62 and around distally projecting sealing post 136 to enter the power nozzles 86, 88. Upon reaching the fluid impermeable barrier of distal end wall 68, the fluid 120 is forced into and through the enlarged inlet regions of power nozzle lumens 86 and 88 and is accelerated transversely and inwardly toward the central axis 64 of exit orifice aperture 74. The opposing transverse power nozzle flow axes 102 and 104 are offset with respect to the distal axis 64 of outlet 74, and are aimed slightly away from or offset with respect to each other, and the inward taper of the venturi-shaped lumens accelerates the fluid flowing along them toward the intersection of the power nozzle outlets 98 and 100 where the opposing flows are aimed into the interaction chamber 84 along power nozzle outlet flow axes 102, 104 as illustrated in
In operation, the swirl or interaction region (e.g., 84) is completely filled with a continuous, rotating mass of liquid, except at the very center (along the exit orifice axis 64, where centrifugal acceleration causes a negative pressure region open to the atmosphere. This region is referred to as the air core. The air core region (as shown in the center of
The device of this first embodiment thus consists of one or more input channels or power nozzles of a selected width and depth, configured to inject pressurized fluid either tangentially into an interaction region, or at another selected inflow angle relative to the walls of the interaction region. The interaction region is preferably circular with a diameter (IRd) which is in the range of 1.5 to 4 times the power nozzle outlet width Pw, and in the preferred embodiment, outlet width (“Pw”) which is preferably about equal to between one third and 0.37 times the swirl chamber or interaction region's diameter (IRd). The interaction chamber preferably has the same depth as each power nozzle, and is arranged so that the fluid flows from the power nozzles and enters the interaction region with a higher tangential velocity Uθ than the fluid entering the nozzles, setting up or generating vortex with radius r and a higher angular velocity w=Uθ/r. The rapidly spinning or swirling vortex then issues from interaction region through the exit aperture 74 which is aligned with the central axis 64 of the nozzle cup member 60. This configuration causes swirling fluid droplets that are generated in the swirl chamber to accelerate into a highly rotational flow which issues from the exit as very small droplets which are prevented from coagulating or recombining into larger droplets when sprayed distally in fluid product spray 152.
Applicant's preliminary development work included experimental findings which were initially thought to show that a critical design parameter was the power nozzle aperture Aspect Ratio (defined as the Power Nozzle Depth divided by the Power Nozzle Width (AR=Pd/Pw)). A gain in angular velocity ω was initially attributed to the velocity profile of fluid flow exiting the power nozzle. Typical prior art swirl nozzles exhibit an AR ranging from 1.0 to 3.0, while an early and promising prototype of the improved swirl cup (“HE-MBU”) device of the present invention had an AR≦1.0. The Aspect Ratio (or cross section Depth over Width) was later discovered to be less critical than initially believed, and the significantly improved performance of the nozzles of the present invention was instead optimized by optimizing the offset ratio “OR” as described above (Pw/IRd).
Another critical part of creating and maintaining sprays of fine droplets is the geometry of the swirl or interaction region's exit orifice. The exit orifice or aperture 74 of the nozzle 60 of the present invention incorporates an outlet or exit geometry (as illustrated in the enlarged view of
(1) a proximal converging entry segment 142 which has a continuous rounded or radiussed shoulder surface of gradually decreasing inside diameter (from the interior wall of the nozzle member);
(2) a rounded central channel segment 144 which is distal or downstream of the converging entry segment 142 and defines a minimum exit diameter segment 146 with substantially no cylindrical “land” (or cylindrical interior surface of constant inside diameter); and
(3) a distal diverging exit segment 148 which has a continuous rounded shoulder or flared horn-like interior surface of gradually increasing inside diameter downstream of the minimum exit diameter segment 146.
Fluid 120 entering the nozzle member 60 and flowing through the power nozzles 80 and 82 into the interaction chamber 84 generate the swirling pattern, or vortex, which flows into entry segment 142, through the minimum diameter segment 146 and out of the exit segment 148 to the atmosphere, as indicated by flow arrow 150. Features (1) & (2) reduce shear losses and retain the maximized angular velocity ω of the swirling distally projecting droplets. Feature (3) allows maximum expansion of a spray cone forming downstream of the minimum exit diameter and minimizes the recombination of the droplets in the distally projecting spray. Sprayed droplets are also referred to as particles, for fluid product spray droplet size determination purposes. For many product sprayer applications, it is preferred that the Volumetric Median Diameter (“VMD” or “DV50”) and domain of the droplet size distribution be as small as possible (meaning, small, uniform mist-like droplets are desired). The flared or diverging shape of Feature (3) prevents VMD losses due to coagulation by maximizing the spray cone angle for a given spray's rotating or angular velocity ω.
The reduced shear losses and larger rotating or angular velocity w combined with reduction in coagulation results in the spray output exhibiting improved atomization. The VMD of the spray droplet distribution is reduced (i.e., has a droplet diameter of 60 μM or less) for a typical pressure and generates smaller and more uniform droplets than prior art swirl cups at any given pressure. The nozzle 60 of the present invention as illustrated in
The many design iterations of the nozzle structure described above permitted applicants to evaluate the most effective design parameters which may be exploited for optimizing angular velocity ω. As noted above, an enhanced understanding of observed gains in rotating or angular velocity ω was found after the above defined “offset ratio” (the ratio of the width of the power nozzle with respect to the diameter of the interaction region) was discovered. As noted above, Prototypes with offset ratios ranging from 0.30 to 0.50 have been tested, and sprayed fluid atomization efficiency was observed to increase as this ratio approaches what was discovered to be an optimum value of 0.37. By substituting the offset ratio for the above-described power nozzle aspect ratio in designing a nozzle configuration in accordance with the present invention, the swirl nozzle geometry can be analyzed in only two dimensions. Particle tracking velocimetry performed with scaled up Plexiglas prototypes and a high speed camera helped applicants to visualize the velocity profile of the swirling fluid of the exit spray (not shown). The offset ratio defines the position and size of the power nozzles relative to the interaction region, and was found to be the dominant variable in controlling the velocity profile of the fluid and maximizing atomization efficiency. The optimum velocity profile through the power nozzle conserves initial kinetic energy and allows for the greatest acceleration of fluid entering the interaction region, generating highest values of rotating or angular velocity ω.
The depth “Pd” of the fluidic circuit of the nozzle, which includes the power nozzle and interaction chambers (80, 82 and 84 in
A second design iteration includes the design of the exit orifice profile described above with respect to
The tooling is more robust in terms of A & B side alignment, and tool wear & required maintenance. In the previous configuration, any misalignment between the two halves of the tool would result in a step at the minimum cross sectional area location (e.g., 146) of the exit orifice. This could potentially change that critical area, or even worse, increase shear losses in flow 150 due to wall friction. Any imperfections in the exit orifice profile (e.g., as seen in
A third iteration of the design parameters is illustrated in the embodiments of
The second embodiment of the High-Efficiency Mechanical Break-Up (“HE-MBU”) nozzle of the invention is illustrated at 160 in
On the interior of the cup member, defined in the substantially circular interior surface 70 of distal wall 68 are the power nozzle circuit 162 incorporating power nozzle chambers 170 and 172 providing fluid communication to and terminating in an interaction or swirl vortex generating chamber 174 and the second power nozzle circuit 168, incorporating power nozzle chambers 176 and 178 providing fluid communication to and terminating in an interaction or swirl vortex generating chamber 180. The power nozzles 166 and 168 are both similar to the nozzle circuit described with respect to
First and second laterally spaced enhanced swirl inducing mist generating structures 166 and 168 are disposed equidistantly on opposite sides of the nozzle member's central axis 64 and are generally parallel to each other, and are formed in the inner surface 70 of the end wall 68 to have their inlet ends 190, 192 for enhanced swirl inducing mist generating structure 166, and 194, 196 for enhanced swirl inducing mist generating structure 168 formed in the interior surface 70 of distal wall 68 proximate the cylindrical sidewall 62. Pressurized inlet fluid flows distally into the interior of the cup and along sidewall 62 to enter the inlet ends and flows inwardly along each power nozzle to enter the respective interaction chambers. As described above, the power nozzles incorporate continuous vertical sidewalls 200 and 202 which define tapered fluid speed increasing venturi power nozzles or lumens which cause the fluid to accelerate along the power nozzles flow path.
As seen in
The spray issuing from the left outlet 162 has a clockwise rotational orientation 204 and a rotational velocity defined by the geometry of power nozzles 190 and 192. The spray issuing from right outlet 164 also has a clockwise rotational orientation 206 and a rotational velocity defined by the geometry of power nozzles 194 and 196. The High-Efficiency Mechanical Break-Up (“HE-MBU”) nozzle member 160 is thus configured to generate first and second fluid product sprays aimed along first and second spaced-apart spray axes, where each spray has a rotational orientation and a rotational velocity, thereby generating a combined spray pattern. In the embodiment illustrated in
Formed in the interior surface 70 of nozzle 220 are first and second HE-MBU enhanced swirl inducing mist generating structure 222 and 224 incorporating respective interaction regions 226 and 228 surrounding their respective orifices 230 and 232. The first or left enhanced swirl inducing mist generating structure 222 incorporates a pair of power nozzle channels 240 and 242 extending inwardly from enlarged regions 244 and 246 at the side wall 62 and tapering inwardly to merge with diametrically opposite sides of the first or left interactive region 226. The axes 248 and 250 of these channels are offset with respect to the corresponding interaction region 226 to produce a swirling fluid flow in region 226; in the illustrated embodiment of
The spray issuing from the left outlet 222 thus has the counter-clockwise rotational orientation 252 and a rotational velocity defined by the geometry of power nozzles 240 and 242. The spray issuing from right outlet 232 has an opposite, clockwise rotational orientation 266 and a rotational velocity defined by the geometry of power nozzles 264 and 266. The High-Efficiency Mechanical Break-Up (“HE-MBU”) nozzle member 220 is thus configured to generate first and second fluid product sprays aimed along first and second spaced-apart, diverging spray axes, where each spray has a selected rotational orientation and a rotational velocity, thereby generating a combined spray pattern. In the embodiment illustrated in FIGS. 11 and 12, the High-Efficiency Mechanical Break-Up (“HEMBU”) nozzle member 220 generates laterally spaced, diverging simultaneous sprays of distally projecting fluid product droplets having opposing rotational orientations and substantially identical rotational velocities. The applicants have observed that for certain fluid product spraying applications, marginally better spray generating performance has been observed from multi-outlet spray devices having such output sprays, with opposite rotational orientations (as compared to multi-outlet spray devices having the same rotational orientation such as is provided in the structure of
In the embodiment of
For the multi-spray embodiments of
The diverging spray HE-MBU nozzle member 220 incorporates interaction or swirl regions 226 and 228, as described above, which are defined between their respective power nozzles as being chambers of substantially circular section having cylindrical sidewalls aligned along the same distally projecting central axis 64 in the distal end wall 68 and aligned with and surrounding respective outlet channel or exit orifices to provide fluid communication between that interaction chamber and the exterior of the cup so that the distally projecting simultaneous fluid product sprays (not shown) are directed along angled spray axes which are spaced from but not parallel to the cup's central axis.
The embodiment of
The principle of improved atomization at higher flows can be extended to multiple swirl geometries. In the exemplary embodiments of
The performance of the nozzle assemblies of the present invention has been measured for uniformity of diameter of generated particles, and the results of such measurements are illustrated in
The nozzles of the present invention can be configured for use with product packages for dispensing a wide variety of products including aerosols using Bag On Valve (BOV) and compressed gas methods to develop higher operating pressures (50-140 psi) rather than costly and less environmentally friendly propellants. The product packages using the above-described nozzle configurations are readily configured for higher operating pressures and can reliably produce a “mist spray” comprised almost entirely of product droplets having a desired small diameter (e.g., 60-80 μM or less, but larger than 10 μM).
Having described preferred embodiments of new and improved nozzle configurations and methods for generating and projecting small droplets in a mist, 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.
This application claims the priority benefit of prior commonly owned copending U.S. provisional patent application No. 62/022,290, filed on Jul. 9, 2014, and entitled “Swirl Nozzle Assemblies with High Efficiency Mechanical Break up for Generating Mist Sprays of Uniform Small Droplets” (Improved Offset Mist Swirl Cup and Multi-Nozzle Cup), and further claims the priority benefit of prior copending U.S. provisional patent application No. 61/969,442, filed Mar. 24, 2014 and entitled “Swirl Nozzle Assembly with High Efficiency Mechanical Break up for Generating Mist Sprays of Uniform Small Droplets” (Mist Swirl Cup). This application is also related to commonly owned U.S. Pat. No. 7,354,008 entitled “Fluidic Nozzle for Trigger Spray Applications” and PCT application number PCT/US12/34293, entitled “Cup-shaped Fluidic Circuit, Nozzle Assembly and Method” issued on Apr. 8, 2008 to Hester et al (now WIPO Pub WO 2012/145537). The entire disclosures of all four of the foregoing applications and patents are hereby incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US15/22262 | 3/24/2015 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62022290 | Jul 2014 | US | |
| 61969442 | Mar 2014 | US |
