US3425600A - Pressurized powder dispensing device - Google Patents

Description

Feb. 4, 1969 R. H. ABPLANALP 3,425,600

PRESSURIZED POWDER DISPENSING DEVICE Filed Aug. 11, 1966 Sheet of 3 Feb. 4, 1969 R. H. ABPLANALP 3,425,600

PRESSURIZED POWDER DISPENSING DEVICE Filed Aug. 11, 1966 Shget 2 of5 INVENTORJ. BERT HENRY AQPLANALP Filed Aug. 11. 1966 Feb. 4, 1969 R. H. ABPLANALP 3,425,600

PRESSURIZED POWDER DISPENSING DEVICE Sheet 3 of 5' v INVENIOR] F- 3 ROM-"RT HENRYABPI AMI/ WMW ATTORNEY).

United States Patent 3,425,600 PRESSURIZED POWDER DISPENSING DEVICE Robert Henry Abplanalp, 10 Hewitt Ave., Bronxville, NY. 10708 Filed Aug. 11, 1966, Ser. No. 571,824 US. Cl. 222193 '11 Claims Int. Cl. B67d 5/54, 5/60; B05b 7/00 ABSTRACT OF THE DISCLOSURE Gas flow passages for the product container of a pressurized dispenser of the isolation type are adapted to assist in urging product toward a discharge ejector by causing turbulent agitation of a powdered product and positive pressure assistance for a viscous product.

The present invention relates to an aerosol dispenser of the isolation type having a construction that renders the dispenser particularly useful for the dispensing of powdered products. In this specification and claims appended hereto, a dispenser of the isolation type comprises a vessel containing pressurized gaseous or gasifiable liquid propellant which is mounted within, but otherwise is separate from a container for fluent product to be dispensed. The propellant and the product are isolated from one another until mixed at or near the discharge port of the dispenser in the course of discharge. In such dispensers, a valve located in the head structure of the propellant chamber normally prevents outflow of the pressurized propellant, but on being opened permits flow of propellant in gaseous (vapor) form to the discharge port. By the action of an ejector (sometimes called a venturi near the discharge port, to which separate flow lines from the product container and the propellant container are respectively connected, the outflow of the propellant when the valve is opened, reduces the pressure in the product flow line and product container and a simultaneous outflow of the product is brought about. By suitably directing the stream of propellant into contact with the stream of fluent product, (conventionally by directing the propellant transversely across the mouth of the product flow line) a spray discharge is produced.

Such a device is described in my copending application Ser. No. 521,885, filed Jan. 20, 1966, now Patent No. 3,326,469 issued June 20, 1967.

It'has been found that dispensers of the isolation type having means providing a positive flow of gas into the product container during discharge are particularly useful to dispense powdered products. In one form of this invention of especial usefulness with powders, a gas flow system is provided which avoids contamination of the powder with moisture.

'Because of the natural tendency of many powdered materials to cake and stack, the absence of a positive flow of gas into the product container during the dispensing step will often result in termination of or heterogeneous discharge of the powdered products.

It is a common observation that an unfluidized powder will tend to form a conical cavity about the entrance to a centrally disposed vacuum eduction tube. This phenomenon is referred to as cavitation. When the cavity extends below the entrance to the eduction tube, further powder discharge will not occur until the agitational force restores the powder level above the entrance to the eduction tube.

With a positive how of gas passing into the product container, the powder is continuously agitated during discharge, thereby fiuidizing at least a portion of the powder and providing a continuous supply of powder to the prodnot flow line leading to the ejector. The gas flow also acts as a carrier and thereby assists the discharge of powder.

According to the present invention, a powder dispenser of the isolation type is provided having means for directing a stream or streams of gas at the powder supply with suificient velocity to agitate or fiuidize the powder and thereby sweep the powder toward the eduction tube. The source of the stream of gas may be atmospheric air which enters the product container through channels directed at the powder surface. The operation of the dispenser reduces the pressure in the product container sufficiently to draw air from the atmosphere through the channels with sufiicient velocity to accomplish at least partial fluidization of the powder.

Alternatively, and particularly useful when product contamination with atmospheric moisture is to be avoided, propellant vapor may be directed from the propellant vessel upon actuation of the propellant valve to supply the agitational force within the product container.

In the drawings:

FIG. 1 is a view in elevation of a powder dispenser according to the present invention showing a surrounding product container in vertical cross-section;

FIG. la is a sectional view taken on line AA of FIG. 1;

FIG. 2 is a view in elevation of another embodiment of the present invention showing a portion of a surrounding product container in vertical cross-section;

FIG. 3 is a view in elevation of a further embodiment of the present invention showing the propellant chamber and a portion of the product container in vertical crosssection; and

FIG. 4 is a view in elevation of a still further embodiment of the present invention showing a surrounding product container in vertical cross-section.

In FIG. 1 a product container generally designated as 20 surrounds the propellant container 10, said container 10 being mounted within the product container by attachment at the mouth 21 of the product container 20.

The propellant container 10 includes a head structure 12 (not shown in detail in FIG. 1) comprising a mounting cup for closing the top opening in the propellant container 10, a manually operable valve assembly for controlling propellant flow, and an actuator 25 which is mounted on a valve Stern extending through a central opening in the mounting cup. The actuator has an ejector to which separate product and propellant lines flow. A product dip tube 11 communicating at its upper end with the product flow line which extends through the propellant container to the ejector. A suitable propellant container and associated head structure is described in United States application Ser. No. 524,527, filed Feb. 2, 1966, Which application is made a part of the disclosure herein.

The propellant container 10 is retained in the mouth 21 of the product container by means of a head 22 formed in the exterior wall of the propellant container 10 and a complementary groove (not shown in section of FIG. 1) formed in the interior wall of the mouth 21 of the product container 20. Spaced about the periphery of the interior wall of the mouth 21 of the product container are grooves or channels 23 which communicate the interior of the product container 10 with the atmosphere, the channels 23 being directed downwardly towards the powdered product 24.

The plurality of grooves 23 and their spacing is best shown in FIG. 1a. The grooves should be relatively small to accelerate the inflowing air to provide .a jet-like stream of incoming air.

Operation of the dispenser causes a drop in pressure in the product container 20. The reduced pressure within the container 20 induces air to rush through the channels 23 and impinge upon the powdered product 24. The air impingement continually agitates and redistributes the surface of the powdered product mass 24 to prevent compacting or stacking of the powder. The fiow of air through the powdered product 24 causes the individual powder particles to be surrounded and buoyed by that air, inflating the mass and permitting the individual particles to move with respect to one another with greater facility.

Another embodiment of the present invention is illustrated in FIG. 2. This embodiment is similar to that of FIG. 1 with the exception of the location of the air channels. In the embodiment of FIG. 2 indentations of splines 29 are provided on the exterior wall of the container 10. These splines provide passages which communicate the interior of the product container 20 with the atmosphere. The splines cooperate with the mouth portion 21 of the container to produce jet forming orifices.

In FIG. 3, the product container 20 is shown in partial section and the propellant container is shown mounted in the mouth 21 of the product container in a manner shown in FIG. 1. In FIG. 3 similarly numbered parts correspond to the parts set forth in FIG. 1. Now to be described is a head structure, generally designated as 30, comprising a manually operable valve unit attached to a mounting cup 31 which forms the closure for the top opening of the propellant container and an actuator 32 positioned in the valve stem 33 which extends through a central aperture 34 in the mounting cup 31. The valve parts 35, 36, and 37 comprise the gasket, valve housing and the body, respectively. The valve body 37 has a central longitudinal passage 39 which extends through the valve stem and communicates at its lower end with the product flow line 9 and at its upper end with the ejector zone 40. The product flow line 9 is sealed to the propellant container bottom by means of a tapered plug 13. The product flow line communicates with a product eduction tube .11 which extends into the product mass. The valve body 37 further has a longitudinal passage 41 which surrounds the longitudinal product passage 39 and communicates at its lower end with the opening 38 in the valve body and at its upper end with the passage 42, which passage 42 communicates with the ejector zone 40 through passage 43.

The actuator 32 is of the construction set forth in application Ser. No. 524,527 referred to above, and further comprises an annular laterally extending portion 46 and an annular skirt 47 depending from the lateral portion 46. The lower portion of the skirt 47 has an annular bead 48 which mates with an annular groove 49 in the exterior wall of the mouth 21 of the product container 20, thereby mounting the actuator 32 to the product container 20 and forming the closed chamber 45. The actuator 32 is fabricated of a material that will permit downward movement of the actuator relative to the product container so as to actuate the valve. For example, the lateral portion 46 may be constructed of a relatively thin section of plastic, such as, nylon or polyethylene, such that upon finger pressure to the surface 50 the lateral portion 46 will flex in a downward direction.

In the valve stem 33 is an opening 44 which permits bleeding of propellant from the passage 41 to the chamber 45 defined by the actuator and its associated lateral portion 46 and skirt portions 47. The bleed passage 44 is of a controlled dimension which permits passage of a limited amount of propellant from the passage 41 to the chamber 45 and ultimately through grooves 23 into the product container 20 whereat it acts to agitate the powder 24 (not shown). The amount of propellant passed through the opening 44 should be limited to permit a sufficient quantity of propellant to pass into the ejector zone 40 so as to effect a pressure drop in the product lines 11 and 39. The amount of bleed off to permit optimum efficiency for each powdered product may be determined by simple experimentation. It has been found that with a powder having a grain size below 60 mesh, an orifice of .010" in a valve stem having a product passage of .050 in diameter will satisfactorily agitate the powder and still produce adequate pressure drop in the product line; the propellant being under a pressure of 70 p.s.i. at 70 F., and the length and inside diameter of the product flow line being 7.0 and .070", respectively.

As an alternate to the opening 44 which may be one or more openings, the exterior of the valve body 37 and its associated valve stem 33 may have one or more grooves or splines which communicate with the propellant container 20 and the chamber 45 upon actuation of the valve.

In operation finger pressure on the actuator 32 will depress the valve body 37 and peel back the gasket 35 in a known manner so as to bring the opening 38 into communication with the propellant vapor. The vapor will pass into the passage 41, through the passages 42 and 43 to the ejector zone 40. The flow of propellant through the ejector zone 40 will cause a pressure reduction in the product flow lines 11 and 39 and effect product flow through 11 and 39 to the ejector zone 40, whereat it is discharged to the atmosphere. Moreover, a portion of the propellant passing through passage 41 will exit through the opening 44 into the chamber 45 from whence the propellant passes through the grooves 23 into the product container 20, whereat it provides an agitational force for the powder.

With the structure of FIG. 3, the powder may be agitated without introduction of atmospheric moisture. A further advantage is that the propellant acts as a fluidizer of the powder with all the attendant advantages of a fluidized system for conveying a powder. Proportioning of the bleed passages 34 and channels 23 will provide adequate downward velocity for the propellant vapor.

It should be noted that the embodiment illustrated in FIG. 3 may also be used to assist the dispensing of viscous liquid products. The propellant bleed passages are then proportioned to provide a pressure within the product container somewhat in excess of atmospheric pressure to assist in forcing product up the eduction tube 9.

The embodiment shown in FIG. 4 includes a distribution tube 26 for introducing gas to the powder mass 24 which communicates at its upper end with the groove 22 and extends downwardly into the powder 24. The distribution tube may be transversely perforated with small apertures 27 to introduce gas to the powder mass 24. The embodiment of FIG. 4 may be employed with tan atmospheric communication at the upper end of the distribution tube 26 as it is illustrated, or may readily be adapted to the propellant bleed system illustrated in FIG. 3 wherein the distribution tube 26 would be used in lieu of channels 23 shown in FIG. 3.

I claim:

1. In a dispenser of the isolation type wherein powdered product and propellant are stored in separate containers each provided with separate flow lines leading to a discharge ejector, the improvement comprising an inlet in the product container open at one end to the atmosphere and in communication with a passage for directing a stream of air to the product with sufficient velocity to agitate the product to. aid its flow to the ejector, said air stream being effected by a reduction of pressure in the product chamber during discharge of the product.

2. In the combination of a container having a powdered product therein and a valved propellant container having a venturi discharge ejector in the valve actuator which dispenses the powder by suction and ejection action, the propellant container being mounted within a top opening of the powder container, and wherein separate powder suction and propellant pressure flow lines are established between the respective containers and the ap propriate chambers of the ejector, the improvement comprising having at least one conduit to the powder container for directing a stream of propellant gas at the surface of said powder at a velocity sufficient to agitate the powder.

3. The combination of claim 2, wherein the conduit is open at one end to the atmosphere and the gas is air drawn through the inlet by eifecting a reduction of pressure within the product container during discharge of the product.

4. The combination of claim 3, wherein the conduit is a groove in the interior wall of the mouth of the powder container.

5. The combination of claim 2, wherein the conduit is a groove in the interior wall of the mouth of the powder container.

6. In the combination of a container having a powdered product therein and a propellant container having a head structure in the top of the propellant container comprising a valve unit for controlling propellant flow and a valve actuator having a venturi discharge ejector therein, the propellant container being mounted within a top opening of the powder container; and wherein separate powder suction and propellant pressure flow lines are established between the respective containers and the appropriate chambers of the ejector, the improvement comprising having at least one inlet to the powder container and at least one propellant vapor port in the propellant flow line, and a passage communicating the inlet to the product container and the propellant vapor port and directed at the powder surface so that upon actuation of the propellant valve a portion of the propellant vapor will pass into the passage to the product container with sufficient velocity to therein agitate the powder.

7. The combination of claim 6, wherein the product and the propellant containers are mounted at their respective top side portions and wherein the separate prodnet and propellant flow lines extend longitudinally through the valve unit including the valve stem, and further wherein the chamber is formed by a lateral flexible portion extending from the actuator and an annular skirt portion depending from the lateral portion; said skirt portion being hermetically attached to the exterior side wall of the product container.

8. The combination of claim 7, wherein the propellant vapor port is a transverse opening in the exterior wall of the valve stem which communicates the propellant flow line in said valve stem and the chamber.

9. The combination of claim 7, wherein the propellant vapor port is a longitudinal groove in the exterior wall of the valve stem which connects the interior of the propellant container and chamber upon actuation of the valve.

10. In a dispenser of the isolation type having a closed product container, a valved propellant container, a valve actuator having a venturi discharge ejector, and a propellant pressure flow line separate from a product suction line each of said lines leading from their containers to the appropriate chambers in the ejector,

the improvement comprising a conduit to the product container in communication with the propellant flow line at a point beyond the valve to effect an increase in the pressure in the product container above that of the product suction line during discharge to assist the ejector in extracting the product.

11. The dispenser of claim 10, wherein the product is powdered and wherein the inlet is in communication with a passage for directing a stream of propellant gas at the product with suflicient velocity to agitate the product during discharge to assist the ejector in extracting powdered product.

References Cited UNITED STATES PATENTS 2,696,933 12/1950 Barclay et al. 222193 X 2,781,154 2/1957 Meredith 222193 3,289,949 12/1966 Roth 239308 X 3,291,346 12/1966 Marrafiino 239-308 X FOREIGN PATENTS 638,023 4/1962 Italy.

ROBERT B. REEVES, Primary Examiner. H. S. LANE, Assistant Examiner.

U.S. Cl. X.R. 222-495, 464; 239-308

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