US2327337A - Dispenser for comminuted solids - Google Patents

Description

Aug. 24, 1943. c. J. BURCH Er Al."

DISPENSER FOR COMMINUTED SOLIDS Filed Nov. 9,. 1940 INVENTQRS vJ. BU RCH CHARLES WILLIAM G. EDWARDS 'ATTORNEY `entrained per unit yvolume of gas.

Patented Aug. 24, 1943 U'r'illlal)k STATES PATENT oFFIce DISPENSER FOR COMMINUTED SOLIDS Charles J. Burch and William G. Edwards, Kenmore, N. Y., assignors to The Linde Air Products Company, a corporation of Ohio Application November 9, 1940, Serial No. 364,958

16 Claims.

The present invention relates to dispensers for comminuted solids, and more particularly to such dispensers wherein a powdered material is entrained by a iiowing stream of a gas and conducted to a point of use. Powder dispensers constructed according to the invention have been found particularly valuable for thermal rock-piercing operations wherein accurately regulated quantities of a powdered flux or iiuxforming material, for example aluminum and/or Silico-manganese, must be congucted continuously to a blowpipe in a flowin stream of gas, such as acetylene. Such thermal rock-piercing operations are described and claimed in application Serial No. 268,634, filed April 18, 1939, by Robert B. Aitchison, Charles W. Swartout, and

' Virgil C. Williams.

. packing of vpowder into the dispenser passages if the dispenserwere subjected to jarring and moving when idle, thus preventing the normal flow of gas and powder when use of the dispenser was resumed, Still another disadvantage of prior powder dispensers was the classifying or separating effect producedv by the flowing gas, which tended to pick up the fine particles and leave behind the heavier coarser particlesof powder.

Among thel objects of the present invention, therefore, are to provide dispensers for comminuted material which will operate continuously and regularly to dispense a large quantityr of material per unit volume of entr'aining gas; which will not be subject to initial clogging; which will operate without a classifying effect upon the particles of material of differentsizes; and which may be regulated to vary the quantity of powder Other objects uf the invention are to provide dispensers for. comminuted materials which will be portable, yet simple, inexpensive, and rugged in construction; and which 'may be dismantled easily for repair or replacement of parts. I

The above and other objects, and the novel features of the invention, will'becomey apparent from the'following description taken with the ac-k companying drawing, wherein:

Fig. 1 is a Vertical sectional View of a preferred form of powder dispenser embodying the invention; n

Fig. 2 is a cross-sectional view taken along the line 2-2 of Figure 1;

Fig. 3 is a view in vertical section of a part of a, powder dispenser, similar to that of Fig. l, but embodying a variation in construction;

Fig. 4 is a vertical sectional view of a modified form of `powder dispenser; and

Fig. 5 is a cross-sectional view taken along the line 5--5 of Fig. 4.

A dispenser constructed according to the invention comprises, generally, a container for a body of ccmminuted material such as powder, means providing a chamber adjacent to the bottom of the container adapted to act as a dispensing zone,

means such as ports for admitting a restricted flow of powder to the chamber from the'con- -tainer, a discharge conduit having its upper end within the chamber above the means for admitting powder thereto, and means for introducing a flowing stream of a gas into the chamber ata locality spaced from the ports to entrain powder and carry it from the chamber through the discharge conduit. For simplicity the term powder will be employed in the following description and in the claims to denote comminuted material of any degree of neness which may be dispensed by apparatus embodying the principles of the invention.

VMore particularly, as shown in Figs. l and 2, the preferred form 'of powder dispenser of the invention comprises a ,vertically arranged cylindrical containerl I for powder, which may be supported in any suitable'manner, as by legs welded to the container, having an internally threaded centrally arranged hollow neck I2 at its upper end through which powder may be supplied to the container. An externally-threaded closure plug I3, having a vertical gas passageA I4 opening at its lower end4 into the top of the container II,is threaded into the neck I2 and has a shoulder I5 clamping a gasket I6 against the top surface of the neck to provide a gas-tight seal. An inlet nipple Il, which is threaded into the top of the closure plug I3 and communicates at its lower end with the top of the passage I4, is adapted nally threaded hollow neck I8 into which is threaded the body I9 of a removable dispensing unit 20, with a shoulder 2| on the body compressing a gasket 22 against the bottom surface ofA threaded cylindrical counterbore21 of relatively large diameter, and another inverted conical counterbore 28 in the upper end of the body I9. A centrally arranged cylindrical dome 29, having an open lower end threaded into the counterbore 21, is provided with conduitmeanssuch as four equispaced inwardly and downwardly inclined ports 30 extending through its sidewalls intermediate its ends and connecting the conical counterbore 28 with the interior of the dome. The inner wall of the dome 29 is spaced from the conduit 25 to provide a small chamber 3|, including the vertical annular space 32, into which a. restricted flow of powder from the container II may be obtained through the ports 30.

A bleeder conduit or tube 33, which is silver solderedor otherwise secured in a centrally arranged bore in the top of the dome 29 in axialv alignment with the outlet conduit 25, opens into the chamber 3| and establishes communication between the interior of the chamber 3I and the space in the container I I outside of the dome 29. The upper or entrance end of the bleeder tube 33, which is adjacent to the top of the container II where it enters the mouth oi' the outlet conduit 25 and assists the delivery of powder to its point of use.

A continuous regular flow of powder is insured bythe described construction because the pressure of the gas on the top surface of the powder mass, and the action of'the gas passing down through the powder, produce a steady and continuous flow .of powdered material through the ports 30 to the interior of the chamber 3|. Classification of the fine and course particlesof powder by the flowing gas is prevented because all of the material which enters the small chamber 3I is entrained by the gas. Moreover, initial clogging is prevented when the dispenser is out of service by terminating the upper end of the outlet conduit a suiiicient distance above the level of the powder ports that little if any powderedmaterial will rise to the higher level and settle into the outlet conduit.

`'I'he ratio of powder to gas in the discharged mixture may be varied between wide limits by above the normal level of the-powder P, is bent 1 at an angle so that its entrance is suiciently offset from the axis of the hollow neck I2 to prevent powder from filling the tube 33 when the dispenser is being charged with powder. A removable and replaceable cap 34, whichis provided with an accurately drilled metering orince 35 'of predetermined size, is threaded over the top of the'bleeder tube 33 tov regulate the proportion of the total amount of supplied gas which will pass through the bleeder tube.

In? the operation of the powder dispenser of Figs. 1 and 2, a flowing stream of gas, such as acetylene, is admitted to the interior of the con- .chamber 3I. This action is amplied by the action of that portion of thegas which flows down through the powdered material P and the ports 3|linto the chamber 3l carrying large quantities of powder into the chamber. The 'gas whichv works its way down through the mass of powder P and the ports 30 lifts the entrained powdered material to the upper end of the conduit 25 and thence carries it out of the vdispenser by way -of gas admitted to the space above the powder level also passes through the orifice 35 and the bleeder tube 33 directly to the interior of the chamber 3I,

I tainer II through the passage I4 and exerts a seal.

y the bore 23 and the nipple 24.` A portion of the providing a number of interchangeable bleeder tube caps 34 having orifices 35 of various sizes, any of which may be placed over the end of the bleeder tube 33 at will to change the proportion of the total supplied gas which passes down the tube 33. Changing the bleeder tube cap 34, as well as repair'or replacement of the other parts of the dispensing unit 20, may be accomplished easily after first removing the unit 20 from the container II by disengaging the threads of the body le from thneck la.

In a somewhat modified form of powder dispenser, the modified construction only being shown in Fig. 3, the construction is the same as in Figs. 1 and 2 except that the lower end or outlet of a bleeder tube 33 is secured in a bore in the top of the dome 29 in an eccentric or offset positionwith respect to the entrance of the outlet conduit 25'. By means of this construction, the portion of the gas passing down through the bleeder tube 33 produces lviolent agitation of the gas and powder in the chamber V3l before it enters the outlet conduit 25', thus providing for .a high rate of powder flow through the ports 30' and the suspension of a. large quantity of powder per unit volume of gas.

In another modified form of powder dispenser according to theinvention, as shown in Figs. 4 and 5, the general construction is similar to that of Figs. 1 and 2, but a somewhat different means is provided for introducing avfiowing stream of gas into the dispensing zone of the, dispenser. The apparatus of Fig. 4 comprises a container 38 having an internally-threaded hollow powder supply neck 31 at the top closed by an imperforate plug 38 bearing against a gasket 39 to provide a A second internally threaded hollow neck 40 is provided at the bottom of the container 38 -for the reception of a removable dispensing unit `4I threaded within the neck 40 and compressing 'a gasket 42 against the bottom surface of the neck to provide a seal. Any suitable means may be used to support the container 38 in vertical position, for example, legs welded to the container.

The removable dispenser unit 4I comprises a `body 43 having a centrally arranged vertical pasin the body'43. A dome 50, having four inwardly and downwardly inclined equi-spaced powder ports in its side walls, the lower edges of the outer ends of which terminate substantially ush with the surface of the conical counterbore 49. is threaded at its open lower end into the cylindrical counterbore 48 with its inner wall spaced from the outer wall of the kdischarge conduit 46 to provide a chamber 52, including the annular space 53 between the two walls. As in the dispenser of Fig. 1, the upper end of the conduit 46 terminates above the level of the powder ports 5I to prevent initial clogging." A bleeder tube 54, opening from the dome 50 at a locality above the ports 5|, is silver soldered 0r otherwise secured in a centrally arranged bore in the top of the dome 50 and establishes,v communication between the chamber 52 and the space above the powder level in the container 36 to provide for equalization of the pressure inthe container. Gas at high velocity is admitted tothe dispensing unit 4| through an inlet nipple 55 threaded into the side of the body 43 and opening into a laterallyextending passage 56 of small diameter inthe body, which in turn opens at its inner end into midway between its upper and lower edges and below the level of the ports 5|.

In the operation of` the powder dispenser of Figs. 4 and 5, a gas, such as acetylene, is introduced in a owing high velocity stream through the inlet nipple 55, the small passage 56, and the oriiice 51 tangentially into the chamber 52 below the level'of the ports 5|. The downwardly and inwardly tapering surface configuration of the conical counterbore 41, and the eccentric arrangement of the orifice 51 with respect to the vertical axis of the dispenser combine to direct f the gas with a high velocity upwardly swirling motion so that it passes upwardly and around in the annular space 53 past 'the inner ends of the ports 5|.

5| and carries it upwardly to the entrance of the conduit 46 wthoutclassifying the fine from the coarse particles. I

The restricted flow of powder through the ports 5| is expedited, and continuity of operation provided by the upwardly swirling motion` of the gas as it passes the ports. Continuity of powder low through the ports 5| also is assisted by the bleeder tube 54, which insures equalization of the pressures inthe'chamber 52 and in the space above the powder level. An additional advantage of providing the bleeder tube 54 is that, after the gas supplied to the dispenser is shut off, the gas stored under pressure in the space above the level of the powder flows downwardly through the bleeder tube 54 and out of the discharge conduit 46 to the hose or other delivery conduit, thus clearing the conduit of powder which may have accumulated. Of` course, as in' the powder dispenser of Figs. 1 and 2, the dispensing unit 4| maybe removed to permit repair or replacement of parts.A

Another important feature of the powder dispenser of Figs. 4 and 5 is that, after the dispenser has been idle or has been freshly filled, the powder which fills the ports 5| and partially lls thechamber 52 will tend to be blown up through the ports 5| and the bleeder tube 54, when the gas is filled introduced, because the pressure in the chamber 52 then exceeds the pressure in the space Y In this way the gas entrains the` powdered material P passing through the port face` of the conical counterbore 41, approximately v above the powder level. Thisv results in a small powder now initially, and allows the unburdenedk gas to clean out any powder which may remain in the delivery conduit from previous operation.

As illustrative of the practicalfunctioning of the powderdispensers of the invention, one-half pound of metal powder, having a mesh size between 65 and 200, has been picked up and carried to a thermal rock piercing operation by each cubic foot of acetylene gas. This is in marked contrast to standard pneumatic conveyor practice wherein flfteen to twenty cubic feet of gas, such as air, are required to convey one-half pound of material, such as wheat or powdered coal. Best results are obtained with the described dispensers when the comminuted material` is of a. type which ows easily and does not have a tendency to stick or agglomerato.

The foregoing description of powder dispensers constructed according to the invention is by way of example only. It is evident that changes may be made in construction without departingfrom the spirit and scopeof the invention, as defined in the claimsappended hereto.

We claim:

1. A powder dispenser comprising a closed container `adapted to hold va supply of powder; a hollow dome within said container adjacent to the bottom thereof, said dome having a side wall provided with port means establishing co-mmunication between the interior of said dome and the g portion of said container outside of said dome for admitting powder to said dome; a powder discharge conduit extending upwardly into said dome and having an entrance in said dome'above the level of said port means for conducting pow'- der from said dome; and means for introducing gas into said container above the normal level of the powder therein, and into said dome for carrying powder to the entrance of said discharge conduit and thence out of the dispenser.

2. A powder dispenser comprising a container means; and means for introducing a flowing stream of gas to the interior of said dome.

3. A powder dispenser comprising a closed container for powder; a dome within said container adjacent to the bottom thereof, said dome hav ing a side wall provided with port means for admitting powder from said container; a conduit establishing communication between the inside of said dome and the-space inside of said container, said conduit having an entrancearranged near the top of said container and adapted to be above the normal level of powder therein;v a powder discharge conduit extending upwardly inside said dome in spaced relation `to said side wall, said discharge conduit having an entrance above said port means 'and spaced therefrom sufllciently that powder cannot rise and enter said discharge conduit to cause clogging thereof.

when the dispenser is idle; and passage means for introducing gas into the space adjacent to the` top of said container above the normal level of powder therein.

4. A powder dispenser as claimed in claim 3, also comprising means providing an orice of predetermined size in said rst-named conduit, said means engaging said conduit and being adapted to be removed and replaced at will.

5. A powder dispenser comprising a container for powder having an opening adjacent to the top thereof for introducing powder into said container; a closure for said opening, said closure having a passage therethrough for introducing a flowing stream of gas into said container above the powder level, said closure being removable and replaceable at will; a dome within said container adjacent to the bottom thereof, said dome having a side wall provided with port means for admitting powder from said container; a conduit establishing communication between the inside of said dome and the space inside of said container, said conduit having an upper entrance end arranged near the top of vsaid container and adapted to be above the normal level of powder therein, said conduit having a lower end opening into said dome substantially centrally through the top thereof; and a powder discharge conduit extending upwardly inside said dome in spaced relation to said side wall, said discharge conduit having an entrance above the level of said port means and spaced therefrom sufficiently that powder cannot rise and enter said discharge conduit to cause clogging thereof when the dispenser is` idle, said entrance being aligned with the lower end of said first-named conduit.

6. A powder dispenser comprising a closed container adapted to hold a supply of powder; a

.hollow dome within said container adjacent to the bottom thereof, said dome having a side wall provided with port means establishing communication between the interior of said dome and the portion of said container outside of said dome for admitting powder to said dome; a powder discharge conduit extending upwardly into said dome and having an entrance in said dome above the level 4of said port means for conducting powder from said dome; and means for introducing a flowing stream of gas into said dome for carrying powder to the entrance of said discharge conduit and thence out of the dispenser.

7. A powder dispenser comprising a closed conltainer adapted to hold a supply of powder; a

hollow dome arranged substantially centrally within said container adjacent to the bottom thereof; said container having a bottom wall sloping downwardly toward said dome; said dome having a plurality of inwardly and downwardly inclined ports establishing.communication between the interior of said dome and the portion of said container outside of said dome for admitting powder to said dome, the lower edges of the outer ends of said ports being substantially flush with the bottom wall of said container; a discharge conduit extending upwardly into said dome and having an entrance at the upper end thereof above the level of said ports for conducting powder from said dome; and means for introducing a flowing stream of gas into said dome for carrying powder to the entrance of said discharge conduit and thence out of the dispenser.

8. A powder dispenser having a closed container for powder; a chamber having a side wall, said side wall having port means therethrough in communication with said container, for admitting powder to said chamber; a powder discharge conduit extending upwardly into said chamber and having an entrance above the level of said port means; passage means for introducing a stream of gas into said contalner'abovethe normal level of the powder therein; and a second conduit having an entrance \in said container wherein said entrance of'said first-named oon-l I' duit and said outlet of said second, conduit are offset from one another.

10. A powder dispenser having a closed con-".-

tainer for powder; a chamber having a side wall, said side wall having port means therethrough incommunication with said container, for admitting powder to said chamber; a powder discharge conduit extending upwardly into 'said' chamber in spaced relation to said side'. wall, thereby providing an annular space around said conduit, said conduit having an entrance above the level of said port means and passage means having an outlet into said annular space below the level of said port means and arranged for injecting a streamof gas approximately vtangentially into said annular space.

11. A powder dispenser according to claim 10,

also having means for directing said stream of gas upwardly in said annular space.'

12, A powder dispenser having a closed container for powder; a chamber having a side wail provided with port means in communication with said container, for admitting powder to said chamber; a powder discharge conduit extending upwardly into said chamber and having -an entrance above the level of said port means; passage means for injecting a stream of gas directly into said chamber at a locality spaced from said port means; and a bleeder conduit having an end opening into said chamber, the opposite end of said vbleeder'conduit opening into the vspace in said container adjacent to the top thereof and above the normal level of the powder therein for introducing gas thereto and equalizing the pres-l sures in said container and said chamber.

p conduit opening from said dome at 13. A powder dispenser comprising a closed container adapted to holda supply of powder; a hollow dome within said container adjacent to the bottom thereof, said dome having a side wall provided with port means for admitting powder to the inside of said dome from the portion of said container outside of said dome; a powder discharge conduit extending upwardly into said dome and having an entrance above the level of said port means; means for injecting a stream of gas directly into said dome; and a bleeder conduit establishing communication between the inside of said dome and the space in said container adjacent to the top thereof and above the normal level of the powder therein, said bleeder a locality above the level of said port means.

14. A powder dispenser comprising `a closed container adapted to hold a supply of powder; a hollow dome within said container adjacent to the bottom thereof, said dome having a side wall provided with port means for admitting powder to the interior of said dome from the portion of said container outside of said dome; a powder' discharge conduit -extending'upw'ardly into said dome in spaced relation to said side wall, thereby providing an annular space around said conduit, said conduit having an entrance above the level of said port means; means providing a downwardly and inwardly tapering surface at the bottom of said annular space below said port means; and means for injecting a stream of gas approximately tangentially into said annular space through said tapering surface.

15. A powder dispensing unit adapted to be mounted in the wail of a powder container. comprising a body; a hollow dome having a top, a side wall, and an open lower end engaging said body and closed thereby, said dome having powder inlet port means in the side wall thereof; a powder discharge conduit secured at its lower end to said body and projecting up into said dome, said discharge conduit having an entrance above said port means; and a second conduit open at both ends, said second conduit being secured to the top of said dome in communication with the interior thereof and extending upwardly therefrom.

16. A powder dispensing unit according to claim 15, wherein said body has a passage in communication with the interior of said dome for supplying gas thereto.

CHARLES J. BURCH. WILLIAM G. EDWARDS.

CERTIFICATE OF CORRECTION. PatentNe. 2,527,557- August 21.4., 19145.

cmnms ...1. BURcH, ET A1..

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5 first column, line 71;, for 'filled read f irt-; and that the said Letters Patent should be read with this correction therein that the same msy oonform to the record of the esse in the Patent Office.`

Signed and sealed this 19th day of October, A. D. 1914.5.,

Henry Van Arsdale, (Seal) Acting Commissioner of Patents.-

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