Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to mist generators and constitues
an improvement of the mist generator disclosed in a copending
application for patent entitled MIST GENERATOR, filed
December 30, 1976, Serial No. 268,912.
The aforementioned application concerns a mist generator
embodying an improved nebulizer which includes means forming a
circuitious path for movement and agitation of the mist and
results in the production of a mist having exceeding fine particles.
The generator is particularly useful for a variety of purposes
including therapeutic applications such as the treatment of lung
disorders, humidification, and the spraying of paints, oils,
insecticides, fertilizers and other liquids.
An object of the invention is to provide a novel and
improved housing for a mist generator which receives the mist
prior to discharge and unctions to remove larger particles and
produce a submicron mist of more uniform particle size.
According to the invention, a mist generator comprises a
frusto-conical housing having a relatively -large base, a small
outlet opening on the top thereof, and a closed bottom wall,
means within said housing for producing a mist, the last said
means discharging said mist into the space defined by said
housing whereby said mist is discharged from said housing outlet.
The frusto-conical housing receives the mist produced by
the mist producing means and functions to remove larger particles
prior to discharge through the outlet at the top of the housing.
While the mist producing means produces in the large part
submicron particles of less than .1 micron, the remaining larger
particles upon being discharged into the housing, will, because
of inertia, strike the wall of the tapered housing and fall to
the bottom thereof.
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The bottom wall of the housing may be concave and form
a liquid reservoir within the housing, the mist producing means
being carried by the bottom wall and aspirating liquid in the
reservoir to produce the mist.
The above and other objects and advantages of the
invention will become more apparent from the following description
and accompanying drawings forming part of this application.
IN THE DRAWINGS:
Figure 1 is a perspective view of a novel and improved
nebulizer in accordance with the invention.
Figure 2 is an enlarged cross sectional view of Figure 1
taken along the line 2-2 thereof.
Figure 2a is a fragmentary portion of Figure 2 showing
a modified embodiment of a chamber therein.
Figure 3 is an exploded view of the nebulizing structure
enclosed within the outer housing as shown in Figure 2.
Figures 4, 5, 6, 7 and 8 are cross sectional views of
Figure 2 taken along the lines 4-4, 5-5, 6-6, 7-7 and 8-8 of
Figure 2; and
Figure 9 is a cross sectional view of the T-tube
disposed on top of the nebulizer as illustrated in Figure 1.
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As previously pointed out the nebulizer in accordance with
this invention comprises a novel and improved arrangement of
elements which functions to produce a more uniformly fine mist
by removal of the larger and undesirable particles. This i9
attained through the utilization of a frusto-conical housing con-
taining the mist generator and which housing preferably includes
a ribbed inner surface. The housing being substantially larger
at the bottom portion facilitates the retention of a larger
quantity of liquid to be nebulized and this is particularly
advantageous when the nebulizer is being used for therapeutic
purposes since a wider range of dosage is available. The
improved housing further includes a chamber which is positioned
in series with the air supply used to nebulize the liquid and
this chamber functLons as a low pass filter to provide a relative-
ly steady flow of air or other gas which is usually derived from
a small compressor.
Referring now to the drawings, and more specifically, to
Figures 1 and 2, the nebulizer is generally denoted by the
numeral 10 and comprises an outer frusto-conical housing 11, a
compressed air inlet 12 and an outlet 13 for the nebulized liquid
14 contained within the housing 11. A T-tube 15 may be affixed
to the top of the nebulizer housing 11 as illustrated in Figure
1. This T-tube is particularly useful when the device is being
employed for therapeutic purposes. It will be understood how-
ever, that the nebulizer in accordance with the invention is
useful for nebulizing other liquids such as oils, paints, chemi-
cal solutions and the like when it is desired to obtain a mist
having an exceedingly fine particles. I !
More specifically the housing 11 consists of a frusto-
conical portion 16 terminating in a cylindrical outlet 13, a
base portion 17, and a capped liquid inlet 13' for feeding liquid
to the reservoir prior to or during the course of producing the
mist. The base portion 17 includes a dished or conical bottom or
reservoir 18 which carries a nozzle 19 extending upwardly from
the center thereof. At least a portion of the space below the
bottom 18 is closed by a cap 20 to form a closed chamber 21 to
receive compressed air or gas entering through the opening 12'
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11 16
on the inlet 12. The nozzle 19~has a central opening 22 which
communicates with the chamber 21 and terminates at its upper end
in a small opening 23. The upper end of the nozzle 19 is pro-
vided with a 45 bevil as denoted by the~numeral 24. The annular
configuration of the end of the nozzle has been found particular-
ly useful in producing a fine mist. It is evide~t, however, that
angles differing from 45 may also be utilized.
The nozzle l9, as viewed in Figures 3 and 8, has a plurali-
ty of channels 25 formed in the surface thereof. A sleeve like
structure 26 having a central opening 27 slidably receives the
nozzle 19 as will be observed more clearly in Figures 2, 7 and
8. The cylindrical structure 26 causes the liquid to be
nebulized to be drawn upwardly through the channels 25.
The upper end 28 of the cylindrical structure 26 is of
reduced diameter and has an opening 29 also of reduced diameter
and which communicates with the opening 27. The opening 27
terminates above the end of the nozzle 19 in a conical conver-
gent portion 30, preferably at a 45 angle, which communicates
with the opening 29. The cylindrical structure further includes
an annular portion 31 of enlarged diameter which has a plurality
of spaced upwardly extending elements 32 forming intervening
slots 33. The upper end of each of the elements 32 is of
reduced section to form a shoulder 34 as will be observed more
clearly in Figure 3. The bottom end of the cylindrical 9 tructure
includes a plurality oP slots or grooves 35 to admit fluid to
the channels or grooves 25, formed in the nozzle 19, during the
aspirating process.
A second cylindrical 8 tructure 36 is arranged to cooperate
with the cylindrical structure 26 as will be observed more
clearly in Figures 2 and 3. The structure 36 has a cylindrical
portion 37 terminating in a lower portion 38 of enlarged dia-
meter and in the nature of a skirt. The inner surface of the
skirt portion 38 as viewed in Figure 2 hss an annular recess 39
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to receive the upper ends of the elements 32 with the shoulder
34 of the elements 32 bearing against the surface 40 as will be
observed in Figure 2. With this arrangement the spaced ele-
ments cooperate with the tubular or cylindrical structure 36
to form a plural~ty of openings 41. The structure 26 also
includes a plurality of outwardly extending spacing or aligning
members 42 which engage in the inner surface of the skirt por-
tion 38 as shown in Figure 2 to insure proper alignment of the
two cylindrical structures 26 and 36.
The top of the cylindrical structure 36 is closed by a
top cap 43 having an annular portion 4~' engaging the top of
the cylindrical portion 37 of the structure 36 to form a closed
chamber 44. A plurality of recesses 45 are formed in the edge
of the top cap to permit the flow of the mist upwardly into the
T-tube 15 or be discharged into the atmosphere or other tubing
that may be connected there~o. 'l`o facilitate removal of the
top cap 43, a short rod like extension 46 is secured thereto
which can be readily gripped by the fingers.
With the apparatus thus far described, a liquid to be
nebulized is placed in the bottom of the housing 16 surrounding
the nozzle 19. Air is fed through the opening 12' into the
chamber 21 whereupon it i9 discharged upwardly through the
openings 22 and 23 in the n~zzle 19. This aspirate8 the liquid
which is drawn up through the channels 25 in the side of the
nozzle19 and produces a mist which enters a first chamber directl~ r
ahead of the nozzle. The mist then passes into a second chamber
formed by the opening 29 in the tubular member 28 whereupon
it is discharged into chamber 44. The mist then passes down-
wardly and is exhausted through the openings 41 formed by the
spaces 33 between the vertically disposed elements 32 and into
the frusto-conical housing surrounding the nebulizing structure.
The resultant mist is then discharged upwardly through the
recesses or openings 45 in the top cap 43.
The particles genera~ed by this nebulizer while in the
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submicron particle size nevertheless, do include particles that
may range in the order of a half micron or possibly larger.
While a substantial portLon of these larger particles are re-
moved by reason of the turbulence created in the production of
the mist in its direction through the chambers and ports, some
of the larger particles, nevertheless, remain and are discharged
with the mist. Since the smaller particles being considerably
lighter in weight tend to rise on entering the chamber surround-
ing the nozzle and the structure forming the chamber 44, the
heavier particles however tend to continue in a given path or
possibly rise only slightly. A substantial portion of these
larger particles therefore strike the converging housing wall
and are returned to the reservoir. Further improvement in the
removal of large particles may be attained by the utilization
of a plurality of ridges 47 formed on the inner side of the
wall 16. These ridges tend to intercept more of the larger
particles and either break them up into smaller particles or
return the liquid back to the reservoir. Thc ridges are pre-
ferably of the order of .85mm to 2mm in height and may be
spa~ced 1 to 5mm apart. The height of the ridges will be depend-
en~ on the viscosity of the liquid being nebulized.
In order to further increase the turbulence of the mist as
it enters the chamber 44, ,the latter may be provided with-an
elliptical, parabolic or hyperbolic curvature as 9hown at 48 in
Figure 2a,
The inclination of the wall 16 of the housing should pre-
ferably be of the order of 50 to 80 with the base of the cone
in order to constrict the mist. Since the larger particles
emerging through the openings 41 will tend to move outwardly a
greater distance than the finer particles constriction of the
mist will have the effect of intercepting the larger particles
and thus, provide a more uniformly fine mist. It has been found
that particl~ sizes as small as .0056 microns can be produced
with this apparatus and while the particles will vary in size a
relatively small portion of the particles exceed .1 microns.
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As previously pointed out one of the uses of this invention
involves the treatment of lung disorders and for that purpose
the T-tube lS is utilized. The tube has a tubular portion 50
adapted to engage the tubular portion 13 on the top of the
housing 11 and a transverse portion 51. On one end of the trans-
verse portion there is a tubular outlet 52 of slightly reduced
diameter which is adapted to receive a suitable mouthpiece for
use by the patient.
The opposing end portion 53 may remain open to the air or
may include a cap 54 or other suitable means to restrict or
control the flow of air into the T-tube. If desired a suitable
hose can be attached in place of the cap 54 for feeding oxygen or
mixtures of oxygen with air as may be desired. The top of the
T-tube includes a small tubular portion 55 having an opening 56
therein for the purpose oE attaching a tube for introducing
liquid into the housing 11. By controlling the flow of liquid
into the housing any prescribed q~lantity oE liquid can be
nebulized. When feeding liquid through the opening 56, collection
on surfaces such as the top cap should be avoided. Accordingly,
the top cap 43 is preferably formed with curved upper suraces on
the outwardly extending leg9. In this way should one of the legs
intercept the liquid drops they will not collect on the surface.
If desired a second top cap 43' formed in the 8ame manner as the
cap 43 may be positioned above the cap 43 and spaced therefrom
by a spacer 50'. In such a case the caps 43 and 43' may be off-
set by about 90.
It is understood that while the nebulizer in accordance with
this invention is highly advantageou9 for use in therapeutic
applications the fine mist is equally useful for humidification
of the air and spraying of all forms of liquid such as paints,
oil, insecticides, fertilizers and the like. In addition while ¦ -
the illustrated embodiment of the invention provides a reservoir
in which liquid is placed, it is, of course, possible to affix
a liquid inlet to provide controlled rate of admission of liquid '
to the reservoir so that the device can operate continuously.
While only certain embodiments of the invention have been
illustrated and described it is understood that alterations,
changes and modifications may be made without departing from the
true scope and spirit thereof.
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