Note: Descriptions are shown in the official language in which they were submitted.
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E~GH PRESSURE SWIRL ATOMIZER
TECHNICAL FIELD
The present invention relates generally to the field of fluid ~tQmi7~tion, and
more particularly to an improved fluid ~loll~llg nozzle for use in m~ml~lly-~ctll~ted
pump dispensers which is capable of generating a fine liquid spray.
BACKGROIJND OF THE INVENTION
Fluid atomizing nozzles are widely used in applications for dispensing of
various consumer hygiene, health, and beauty care products (e.g., hair spray
dispensers, aerosoi deodorant spray dispensers, nasal spray dispensers and the like).
More specifically, devices incorporating fluid atomizing nozzles for dispensing
conc~mPr products are generally of either the m~n-~lly_~ct~-~ted pump type or the
aerosol type. Manually-act~ted pump dispensers typically include a piston and
cylinder arr~ngpmpnt which converts force input by the user (e.g., sq--eP7ing a pump
lever or depress.l g a finger button) into fluid pressure for atomizing the liquid
product to be tlicrçn.ced The liquid product is generally directed into an atomizing
nozzle having a swirl c~l~mbP,r where the rotating fluid forms a thin conical sheet
which breaks into lip~...e~.ls and discrete particles or drops upon exiting to the
ambient en~;.on.n~
Aerosol dispensers, on the other hand, typically incorporate a pressurized gas
(e.g., generally a form of propane, isobutane or the like) which is soluble with the
liquid product to aid in ~lo...;~;Qn. When the liquid product is dischal~ed from the
p~n.cç~, much in the same manner as with a m~n~qlly actu~ted dispenser, the gas
"flashes off'' (i.e., sepal~l~s out ofthe liquid and returns to its gaseous state), thereby
~c~ictinS~ the ~lon,~alion process by causing some of the liquid to break apart into
i~,iq.n~...lc and discrete particles or drops. Thus, the liquid in an aerosol type
~1icpencPr is atc.l-"~ed by both the phase change of the pressurized gas as well as by
the ~wi lin~ motion of the liquid as it exits the swirl cl.~...l,çr. It has been found,
however, that aerosol propellants are often not plefe..cd such as for reasons ofen~i.on.n~ l concellls for PY~mrle Nozzles desi~P,d for operation with an aerosol
~ dispenser, however, will generally not produce the same spray characteristics when
adapted for use in a m~n-l~lly ~c~tl~ted pump dispenser.
The spray characteristics of an aloll~i-,g nozzle (e.g., drop size, spray angle,spray penetration and p~ alion) can be illlpOI l~ll for achieving consumer
s~ticf~ction with a dispellscd product. For ~ ~A...rlç7 in hair spray applications, it can
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be advantageous to generate a spray having a smaller mean particle size (e.g.,
generally about 40 microns), as sprays with larger particle sizes may create a
perceptively "wet" or "sticky" spray because the drying time for the larger particles
is co..es~,ondingly longer. One method for decreasing an atomized spray's mean
particle size is to increase the liquid pressure, which, in turn, increases the angular
velocity of the liquid within the swirl chamber and generally results in a thinner film
and hence a finer spray. However, because the required increase in pressure mustgenerally be accomplished in a m~n~lly-~ctll~ted pump r~i~p~n~er by increasing the
hand ~rt~tion force, this type of ~ pen.eer may be less desirable to consumers
because of the increased effort required for its operation. Consequently, an
atomizing nozzle which can generate a spray having the desired mean particle size of
about 4G microns with the lowest possible hand ~chl~tion force would be desirable
for use in m~nll~lly-act~l~ted pump dispensers. Heretofore, this combination of
features has not been available.
The spray characteristics of an atomizing nozzle are generally a function of
the viscosity of the liquid to be ~icp~n.~ed, the pressure of the liquid, and the
~eo.,.el.~ of the alo,-li~-,g nozzle (e.g., orifice ~ meter, swirl chamber ~ meter~
vane cross section~l areas and the like). The prior art in the fluid i.lo~ g industry
close~ a variety of fluid atomizing nozzles for use in m~ml~lly-actll~ted pump
dh,l~ense-, or, in aerosol dispensers, in which these parameters have been co.nbilled
to achieve specific spray characteristics. For example, commercially available
lQ~ g nozzles may be adapted for use in m~ml~lly-~r.tl-~ted pump dispensers of
co~.. er products. The con~lne-Gial alo.. i~ing nozzles of which the applicant is
aware are generally co,-.l..ised of a plurality of generatly radial vanes which exit into
a swirl Ch~ /G. being generally concentric with a dischalge orifice. These known
~lo...;,;n~ nozzles typically have a swirl chamber rli~n ete~ in a range of between
about 0.75 mm and about 1.5 mrn, an individual vane exit area in a range of bet~,veen
about 0.045 mm and about 0.20 mm, and a discharge orifice di~mPter in a range ofbetween about 0.25 mm and about 0.50 rnm. It has, however, been observed by the
applicant that in order for these alo--.~--g nozzles to form a spray having the desired
40 micron particle size, fluid inlet pressures greater than or equal to 200 psig are
required.
In the patent area, U.S. Patent No. 4,979,678 to Ruscitti et al. discloses an
~o-n;,;.~g nozzle having a series of spiral turbulence Gh~nn~ which exit into a
turbulence cl.a---ber that is coaxial with the nozzle exit orifice. U.S. Patent No.
5,269,495 to Dobbeling similarly illustrates a high pressure atomizer having a liquid
feed ~nmllu~, a plurality of straight radial supply ducts, and a turbulence chamber
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with an exit orifice. The liquid enters the turbulence chamber through the radial
supply ducts where it impinges upon liquid e-lLtli,.g from an opposing turbulence
duct. This impingPmPnt is to create a "shearing action" which allegedly atomizes the
liquid. This atomizer, however, is taught as requiring, inlet fluid pressures
appro~ching 2200 psig to achieve this "shearing" effect.
While the above rli~c~ ed prior atomizing nozzles may function generally
s~ficf~tQrily for the purposes for which they were ~e~igner~, it is desirable to provide
an improved ato~ * nozzle with structural and operational advantages of finer
spray characteristics with convenient and effiri~nt manual activation. Heretofore
there has not been available an atol.~--g nozzle for use in a m~n~ y-actl~ted pump
dispenser having a simple, easily m~n--f~ctl-rably swirl chamber and vanes whichwould be capable of producing an atolui~ed liquid spray having a 40 micron or less
mean particle size with a required activation liquid pressure generally below 200 psig.
SUMMARY OF THE INVENTION
An ato--fi~-* nozzle is provided which is capable of producing a spray of
liquid product having about a 40 micron particle size with an activation liquid
pressure of about 160 psig. The ~lo...;~ nozzle comprises a supply structure fortransporting a pressurized liquid from a co..la;-lel, a plurality of generally radial
vanes, a swirl chamber having a chamber ~ mP~ter~ and a discharge orifice having an
orifice ~ mptçr.
The plurality of vanes are in fluid communication with the swirl chamber and
have a generally decreasing individual vane cross sectional area toward the swirl
.h~...l-r,r. The swirl cl~ -bPr is similarly in fluid cQmmlln;~tiQn with the discha-ge
orifice for releasing an atomized liquid product to the ambient environment The
plurality of vanes pler~-~bly have a c~m~ five vane exit area being in a range of
between about 0.18 mm2 and about 0.36 mm2 in combination with a swirl rll~mhPr
...e~e. of between about 1.3 mm and about 2.0 mm. It is more p,er~,.ed, however,that the plurality of vanes con~i~tC of three vanes with each vane having an individual
vane exit area being in a range of between about 0.06 mm2 and about 0.12 mm2, and
with the discharge orifice having an orifice .I;h.... lP- being about 0.35 mm.
BRIl~F DESCRIPTION OF THE DRAWINGS
While the speçifir~ti~rl cQnr~ es with claims particularly pointing out and
~lictin~.tly rl~imin~ the present invention, it is believed the same will be better
understood from the following description taken in conj~lnction with the
accol.lpal.j~ng drawings in which:
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FIG. 1 is an enlarged cross sectional view of an atomizing nozzle made in
accordance with the present invention;
FIG. 2 is an enlarged cross sectional view of the nozzle body of FIG. 1,
illustrated without its nozzle insert for clarity;
FIG. 3 is a rear elevational view of the nozzle insert of the ato~ .g nozzle
ofFIG. l;
FIG. 4 is an enlarged cross sectional view ofthe nozzle insert in FIG. 3, taken
along line 4-4 thereof;
FIG. 5 is a graphical illustration of the general relationship between swirl
cll~--ber ~i~mepr and individual vane exit area in an ~tO~ 7;l~g nozzle; and
FIG. 6 is a graphical illustration of the general rel~tionchip between liquid
pressure and mean particle size of an atomizing nozzle of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present l~.eÇt:.. t;d embodiments ofthe invention, an example of which is illustrated in the acco--lpal.ying drawings
wherein like numerals in-iir~te the same ~ nl~ont~ throughout the views. FIG. 1 is an
enlarged cross secti~ n~l view of an ~tomi7ing nozzle 15 made in accordance with the
present invention for use in a m~m-~lly-~ctu~tecl pump type liquid product dispenser.
.At~mi~ing nozzle 15 comprises a nozzle body 20 and a nozzle insert 21. As best
illustrated in FIGS. 1 and 2, nozzle body 20 can ~refe,ably be provided with a
generally cylindrically shaped interior and may have various external configurations
or structures which may aid the user in operation of the dispenser (e.g., raisedpin~, surfaces, dep-tss;ons for finger pl~c~mf~nt and the like). Nozzle body 20 is
further illustrated as inrlllding nozzle feed p~c~ge 22 disposed therein for receiving
feed tube 23, such as by a frictional i..le,rel~nce fit between passage 22 and feed tube
outer surface 24. The frictiona1 co.~eclion, more commrJnly known as a press fit,
,en feed tube outer surface 24 and nozzle feed passage 22 can p-t;re,ably b
snug but removable to f~rilit~te cl~ g or rinsing of debris which may otherwise
build up and clog the atc,...,~ g nozzle.
~ ;re.~bly, the co~ onding surfaces of nozzle feed passage 22 and feed
tube outer surface 24 are provided of approp.iale size and material to effectively
create a seal therebetween so that there will be generally no liquid flow between the
surfaces when the di~pens~r is in operation. Although it is pt~;r~-led that nozzle feed
tube 23 be r~;lained by simple frictional interaction with nozzle feed passage 22, it
will be understood by one skilled in the art that feed tube 23 may be connected to
nozzle feed passage 22 by alternate means such as adhesive connections, welding,
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merh~nical connectin~ structures (e g, threads, tabs, slots, or the like), or by integral
m~nllf~chlre with nozzle passage 22.
Feed tube 23 is to provide fluid comm~miC~tion with a suitable liquid storage
container (not shown) so that the liquid product to be ~iepPneed may be L.~.ls~-o.led
from the container to ato-- ~ing nozzle 15 Feed tube 23 may ,ol~re,~bly form part of
a valve stem for a conventional piston and cylinder ~l~'~g~ ~ ~nt or other dispensing
arr~ngPmPnt (not shown) which generates the liquid pressure required for operation
of atomizing nozzle 15.
A generally plug-shaped insert post 26 is preferably disposed a~ cPnt feed
tube 23, as best illustrated in FIGS. 1 and 2. Insert post 26 p~Çt;~bly has a
s~1bst~nti~lly planar end surface 28 a~ cPnt its distal end, and insert post surface 30
End surface 28 is generally circular shaped when viewed from the direction indicated
by the arrow in FIG. 2 Insert post 26 can be a separate structure which may be
~tt~çheci to nozzle body 20 by a meçh~nic~l means (e.g, threaded, press fit or the
lilce), but will preferably be integrally formed with nozzle body 20 for ~eimrli~ity of
m~nllf~ctllre (such as by injection molding) Supply cha...l)el 32 generally forms an
annulus which is bounded by post surface 30 and inside wall 34 P,ert:l~bly, supply
. h~ ~he 32 is a~ c~nt to and in fluid comm~-niC~tion with feed tube 23 to initially
receive fluid from the storage container.
As best seen in FIGS 3 and 4, nozzle insert 21 is p-ert-~ly generally
cup-shaped, having a cavity 38 with a cavity surface 39 and an end face 40 Located
CPnt to end face 40 and generally CQI~'e~lniC with the cenle-line of 38 is swirlchamber 42, illustrated with a ch~..k di~mpter CD Swirl chamber 42 preferably
has a generally conical shape for flow Pffi~i~ncy (i.e, minim~l pressure drop),
though other commoll co,~"--a~ions such as bore shapes may also be sl it~bl~
A discharge orifice 44 having a predGIt..,~ned orifice di~metPr (OD) is
preferably located ~djacPnt to and generally conce.l~-ic with swirl chamber 42.
Disch~ye orifice 44 thereby provides fluid comm~niG~tion between swirl chamber 42
and the ~llb-'t ~t en~/iro,l---e--~. As best illustrated in FIG 3, a plurality of grooves 46
are preferably disposed on end face 40 PYt~n-ling generally radially inward fromcavity surface 39 to conical swirl ch~mhf~r 42 In a p.er~l.ed embodiment, each
groove 46 connecl~ generally tangentially with swirl chamber 42 and nozzle insert 36
has at least two spaced grooves 46. In the embodiment shown, nozzle insert 36 has
three grooves 46 disposed generally radially and eqlli~iet~nt about swirl chamber 42,
as best illustrated in FIG. 3.
The inside wall 34 of supply chan.l)e. 32 is preferably sized to receive and
frictionally retain nozzle insert 21. Alternatively, nozzle insert 21 may include a ring
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or other locking device (not shown) for m.och~nically mating with a sl~t or similar
structure corresponding with the locking device (not shown) and disposed about
inside wall 34 so that nozzle insert 21 will be positively retained within nozzle body
20. Preferably, the surfaces of inside wall 34 and insert surface 37 are sized such that
when assembled in contact with each other, they will create an effective seal and
there will be generally no liquid flow between the surfaces when the dispenser is in
operation.
When nozzle insert 21 has been fully assembled with inside wall 34 of nozzle
body 20 such that end surface 28 and end face 40 are in contact (as best illustrated in
FIG. 1), a plurality of generally lec~ P,~l~r vanes 48 and a supply ~nmllll~ 50 are
ned Supply ~nmllll~ 50 is preferably formed beLv~ n cavity surface 39 and post
surface 30, and extends along at least a portion of the length of cavity surface 39
such that supply ~nmllllc 50 is in fluid comm~n:c~tion with both supply chamber 32
and one or more contiguous vanes 48.
Vanes 48 are plel~l~bly defined by the juxta position of end surface 28 of
insert post 26 and grooves 46 of insert 21. Each vane 48 has a res--ltir~ width W and
height H which, in turn, defines a vane cross sectional area A in accordance with the
equation:
A = W * H
Thus, the individual vane exit area EA of each vane exit 52 is the product of exit
width EW of that vane and height H, while the individual vane inlet area L~ of each
vane inlet 54 is similarly the product of height H and the inlet width IW. The
cum~ tive vane inlet area for an aloll--~g nozzle made in accordance with this
invention is, Il.e.t~olt" the s~mm~tion of the individua1 vane inlet areas IA while
similarly the cum~ tive vane exit area for an alo~ lg nozzle is the s~mm~tion ofthe individual vane exit areas EA.
Pl-,fw-.,d vanes 48 will feature a contin~lol~sly inwardly decreasing width so
that EW is generally less than IW while height H is generally con~la.ll over the length
of each vane 48. Because height H is prefw~ly ~ ed generally consl~r.l over
the radial length of vane 48, the ratio of the vane exit area EA to vane inlet area IA is
generally equal to the ratio of the vane exit width EW to vane inlet width IW.
Consequently, both ratios preferably define the nall~Wing conrol.n~ion of each vane
48. This narrowing confollll~lion ~-e~lably provides a continuously acceleratingliquid flow within each vane 48 as the liquid traverses each vane 48 in a direction
from supply challll,cr 32 toward swirl chall~L,el 42.
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Although it is preferable that the width (and similarly the cross sectional areaA if the vane height H is consl~l) of each vane 48 continuously decreases inwardly
from cavity surface 39, it has been found that the spray characteristics of liquid
dispensed from nozzles made according to this invention are generally il~e~ ;ve to
the amount of decrease in the vane width W. Thus, it is believed generally that the
ratio of the vane exit width EW to the vane inlet width IW, and likewise the ratio of
vane exit area EA to the vane inlet area IA (if vane height is consl~), may vary in a
range from about 0.10 to about 1.0 without generally deviating from the scope of this
invention.
Not int~?n~in~ to be bound by any particular theory, it is believed that proper
~lim~ncioning of the cross sectional exit area EA of vanes 48 in cooperation with the
proper sizing of cllamber diameter CD and orifice ~ metçr OD is critical to achieving
the spray characteristics of the present invention. For example, it has been observed
that as chamber ~ meter CD and individual and c~-m~ tive vane exit areas increase,
the Sauter Mean Diameter (i.e., a quotient ~e~lesç~ g the average particle size of a
spray) of a given spray generally decreases accolding to the following equation, and
as graphically illustrated in FIG. 5:
SMD = 44.6 - 57.1 * (CD * EA)
where SMD = Sauter Mean Diameter in microns.
CD = Chamber fli~m.o,t~r for values generally
in a range of between about 0.5 mm and
about 1.5 mm.
EA = Individual vane exit area for values
generally in the range of between about
0.02 mm2 and about 0.07 mrn2.
Although FIG. 5 in~ic~tes a generally decreasing particle size as individual
vane exit area EA and/or çh~mher di~ eler CD increase, data generally in-lic~t~c that
the Sauter Mean DiallleLel of a resulting spray was found to generally increase if the
individual vane exit area EA is about 0.12 mm2 and cl-alllber rli~meter CD is about
2.0 mm.
Based on the fore~,oi-lg relationships, it is believed that plerelled
embo-lim~ntc of the present invention will have a c~-m~ tive vane exit area (i.e., a
sllmm~ti~n of the individual vane exit areac EA) in a range of between about 0.18
mm2 and about 0.36 mm2 and generally a challll~er ~ meter CD in a range of
between about 1.3 mm and about 2.0 mm, and most preferably the chamber ~
CD being in a range of between about 1.4 rmn and about 1.5 mm. It has been foundby the applicant that these ple~lled emborlimentc will generally produce a spray
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being in the range of between about 38 microns to about 43 microns with a liquidpressure being in the range of between about 160 psig to about 200 psig.
Nozzle body 20, feed tube 23, and nozzle insert 21 may be constructed from
any subst~nti~lly rigid material, such as steel, ~lnmimlm or their alloys, fiberglass, or
plastic. However, for economic reasons, each is most plc:re,~bly composed of
polyethylene plastic and formed by injection moll1in~, although other processes such
as plastic welding or adhesive connectiQn of app,~pliale parts are equally applicable.
In operation of a prere,l~d embodiment of the present invention, liquid
product is provided from a container through feed tube 23 under pressure created by
a m~nll~lly-~ctu~ted piston and cylinder arrangement, or other m~ml~lly actu~tedpump device. The fluid, upon exiting feed tube 23 enters supply chamber 32
whereupon it longitu-~inAlly traverses nozzle body 20 and enters supply annulus 50.
The pressurized liquid then passes through supply annulus 50 and is directed into the
plurality of vanes 48. ~lthollgh it is prefe".,d that feed tube 23, supply ch~mhçr 32
and supply annulus 50 cooperate to transport the liquid from the corllainer to the
plurality of vanes 48, it should be understood that other supply structures (e.g.,
ch~nn~olc, chambers, reservoirs etc.) may be equaUy suitable singly or in combination
for this purpose. rler~,~bly, the liquid is continuously accelerated by the decreasing
cross sectional area A of each vane 48 which directs the liquid radially inward toward
swirl ch~"ber 42. The accelerated liquid plefe.~bly exits the vanes 48 generallytangentially into swirl chamber 42, and the rot~ti~-n~l energy imparted to the liquid by
each vane 48 and the 1~-1g~ ;Al mo~.,."t;nl into swirl r~ h~ 42 generally creates a
low pressure region adjacent the center of swirl .~ .,.h~l 42. This low pressureregion will tend to cause ambient air or gas to p~.,c;l,~e into the core of swirl
chamber 42. The liquid then exits swirl çh~mb~r 42 as a thin liquid film (surrounding
afol~ ;oned air core) and is directed through discharge orifice 44 to the a",bie"l
en~,;.ol~n~ . Upon discha~e, inherent instabilities in the liquid film cause the liquid
to break into lig~ment~ and then discrete particles or d,oplelst thus forming a spray.
As best illustrated in FIG. 6, a p~cr~ ;d embodiment of the present invention
genelales a spray of liquid particles or dlu~'et~ having a mean particle size of about
40 microns at a fluid ples~.lle of around 160 psig when used to dispense a fluidhaving a viscosity of about 10 ce.,lipoise. For co~"pa~ison only, the best knownco,...~P~,ially available nozzle of which the appli~ l is aware which may be adapted
for use in a manual~ u~ted pump di~pe~se~ generally produces a spray having a
mean particle size of about 40 microns at a pressure about 200 psig or more for a
liquid of such viscosily. The appro~ e 40 psig p~ ul~ red~lctiQn in that exampleto achieve generally a 40 micron mean particle size advantageously l~itnCl~tes into a
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lower input force to create the necçc~ry fluid pressure. Consequently, the user of a
m~ml~lly-~ctll~ted pump type dispenser Co~ g an atomizing no_zle embodying
the present invention would have to exert less force to achieve generally a 40 micron
spray, and the device itself would presumably be easier and less expensive to
m~mlf~cture due to the lower pressure requirements.
While the structure of the present invention is not intçnded to be limited to
the dispensing of any specific product or category of products, it is recognized that
the structure of the prerel,ed embodiments is particularly efficient and applicable for
the dispensing, at pressures about 160 psig, of liquid products having a viscosity,
density, and surface tension generally about 10 centipoise, 25 dynes per cPntimetP~
respectively. It will be understood by one skilled in the art, however, that deviation
from these values for applopli~le di~rele.~l applications and/or for dispensing of
various liquids and viscosities should be possible without af~ecting the spray
characteristics of the present invention. For example, it is believed that the viscosity
of the liquid to be ~ pP~n~e(l may vary from about 5 cps to 20 cps without deviating
from the scope of this invention.
The fol~oi"g description of the pler~lled embo~imPnt~ of the invention has
been presented for purposes of illustration and description. It is not inten-~ed to be
PYh~lstive or to limit the invention to the precise form disclosed. Mo~ifi~tic)ns or
variations are possible and conlelllpla~ed in light of the above te~chingc by those
skilled in the art, and the embodiments ~icc~lcsed were chosen and desclil,ed in order
to best illustrate the principles of the invention and its practical application, and
indeed to thereby enable ~Itili7~tiQn of the invention in various embotlimPntc and with
various moriific~tions as are suited to the particular use contemplated. It is intPn-lPd
that the scope of the invention be defined by the claims appended hereto.
