US3265098A

US3265098A - Method and apparatus for packaging loose aggregate materials

Info

Publication number: US3265098A
Application number: US253556A
Authority: US
Inventors: Harry D O'neal; Robert B Wheeler
Original assignee: ST Regis Paper Co
Current assignee: ST Regis Paper Co
Priority date: 1963-01-24
Filing date: 1963-01-24
Publication date: 1966-08-09
Anticipated expiration: 1983-08-09

Description

Aug. 9, 1966 H. D. ONEAL EI'AL METHOD AND APPARATUS FOR PACKAGING LOOSE AGGREGATE MATERIALS INVENTORS. Hfl/EEYD. O/VEAL BY P055273 WHEEL E2.

HUU/PIVE 2 Sheets-Sheet 1 Filed Jan. 24, 1963 Aug. 9, 1966 H. D. ONEAL ET AL 3,265,098

METHOD AND APPARATUS FOR PACKAGING LOOSE AGGREGATE MATERIALS 2 Sheets-Sheet Filed Jan. 24, 1963 v QMkQMms him \sM INVENTORS.

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Z L z WE w W H 95. mm M g m United States Patent Office 3,255fi98 Patented August S, 1966 3 265,098 METHOD AND APPARATUS FOR PACKAGHNG LOOSE AGGREGATE MATERIALS Harry D. ONeal, Seekonk, Mass, and Robert B. Wheeler, Bellaire, Tex., assignors to St. Regis Paper Company, New York, N.Y., a corporation of New York Filed Jan. 24, 1963, Ser. No. 253,556 9 Claims. (Cl. 141-5) This invention pertains to methods and apparatus for dispensing and packaging loose, aggregate materials having a particle size, such as to permit of dispensing by flow of air or other gas under pressure, but nevertheless such as to permit of forming an efiective gas seal under a hydrostatic head thereof of substantial pressure. Such materials are generally characterized by a granular or pellet-like particle size, and are exemplified by such materials as dry sand, dry sand-cement gravel aggregates, plastic pellets or gravel, seed corn, peas, shelled beans, etc.

The invention pertains more particularly to improvements in so-called force flow packers, wherein the aggregate material is dispensed from a bin through a discharge spout thereof and into a packaging container, such as a paper bag, by the injection of gas, such as air, under pressure in the bin, and under conditions such that the bin except for the spout outlet, is otherwise effectively sealed against the outer atmosphere during the discharge, whereby the material is forcefully discharged through the spout by the pressurized air flow either without or with fluidation of the material.

The invention has as one of its objectives, a simplification of apparatus and methods heretofore deemed necessary for dispensing and packaging loose aggregate materials of the character aforesaid, whereby apparatus components and manipulative operations are eliminated as compared to practices of the prior art.

The invention provides as another of its objectives apparatus of the character aforesaid having greatly increased operating life without repairs, and reduced downtime for repairs and replacement of parts as compared to prior such apparatus.

The invention provides as still another of its objectives, apparatus as aforesaid which is far superior to existing devices for the packaging of abrasive materials or pelletized material of -a particle size such as tends to jam and block mechanical closure members of existing packaging mechanisms.

These and other advantages of the apparatus and methods of the invention as compared to packaging mechanisms and techniques heretofore utilized for the above stated, purposes, will become apparent as the description proceeds.

Force flow packers of a type which have heretofore proved highly effective for dispensing a Wide variety of loose aggregate materials are described in a copending application of O. R. Titchenal and I. H. Stockwel, Serial No. 810,465, filed May 1, 1959. This apparatus in one embodiment, comprises a vertical dispensing or packer bin, usually cylindrical, of a length exceeding its width, and having a discharge spout at the base, a fluidizing air pad adjacent the spout, valve connected to a compressed source, which is also valve connected to a pipeline penetrating the bin sidewall near the top and terminating within the bin preferably in a disseminator or perforated tubular member extending axially of the bin for a substantial distance for disseminating the air flow throughout the mass of material. The bin is closed oif at the top except for a restricted aperture, opening into the base of a supply bin disposed above the packer bin to provide an infeed passage for periodically charging the aggregate material from the former into the latter by gravity feed. The discharge spout and infeed passages are provided with electrically or pneumatically actuated mechanical closures for shutting off or releasing the flow of material. Means are also provided for venting the packer bin to atmospheric exhaust.

According to one mode of operation, with the packer bin vented to atmosphere and the compressed air supply shut off, the infeed closure is opened to discharge the packer from the supply bin while maintaining the discharge spout closed. The infeed closure and bin vent are then shut, and with the compressed air supplied to the fluidizing pad and disseminator, the spout is opened to discharge the material into a bag or other container afiixed to the spout. When the bag is filled to a preselected weight, the spout is closed, the air supply shut off, and the packer bin again vented to exhaust, and the bin recharged as aforesaid.

Now We have discovered in accordance with the present invention, that for packaging loose aggregate materials of the character and having the properties set forth above, namely, those which may be dispensed by compressed air flow but which nevertheless compact to a sufficient density under a hydrostatic head of a hundred pounds or so, so as to provide an effective air or gas seal over a restricted aperture of exposure, that it is not necessary to effect mechanical closure of the infeed duct between the supply and packer bins during discharge of the aggregate material from the latter through the discharge spout, provided the following con ditions are met. That is to say, 'we have found that the need for mechanical closure of the infeed passage between the storage and packer bins may be eliminated, if the infeed duct passage is made of sufficiently small aperture and of sufiicient length, and if concurrently therewith the disseminator is so dimensioned or positioned that its lower end extends down substantially to the level of the dispensing bin discharge spout. We have found that under these conditions the loose aggregate material itself forms and maintains an effective air seal in the infeed duct, while the packer bin is being discharged. The apparent reason for this is that during discharge of the packer bin contents into the packaging container, it is easier for the compressed air injected into the packer bin, to flow from the disseminator to the discharge spout than it is for the air to flow from the disseminator back up through the material bed into the supply bin above. Apparently also the upsurge of air under pressure from the disseminator combined with the compacting action of the hydrostatic head of material in the supply bin, so compacts the material within the duct as to plug it during discharge from. the spout.

It was found by experiment, that during discharge of the packer bin the aggregate material automatically bridges across the infeed duct, and thereby (prevents material in the storage bin from falling into the packer bin during discharge of the latter. It Was further observed that shortly after the air supply to the packer bin is shut oft and the iatter vented to exhaust, the bridge of aggregate material in the infeed duct collapses, permitting the material to fall from the supply bin into the packer bin and thus refill the latter. As a necessary condition for this observed operation, it was found that a sufficient hydrostatic head of the aggregate material was required to be maintained in the supply bin, on the order of about to 300 pounds over the cross-sectional area of the infeed duct, depending on the material being packaged.

Thus according to our observations the combination of factors apparently conducive to formation of the material bridge across the infeed duct and consequent air seal produced thereby are: the packing effect of the hydrostatic head of the aggregate material in the supply bin, the restricted aperture. of the infeed duct and the use of a relatively long disseminator, the lower end of which terminates reasonably close to the opening with the packer bin discharge spout. The length of the infeed duct also appears to be a factor, in that it must be of sufificient length to permit formation of the material bridge therein. Exemplification of these apparent controlling factors will be given below.

We have observed as a further object of our invention, that the fiuidizing air pad at the base of the packer bin is not required, but may be used to advantage under certain conditions of operation.

Having thus generally described our invention, reference will now be had for a more detailed description of the above and other features, to the accompanying drawings, wherein:

FIG. 1 is a more or less schematic or diagrammatic view in elevation, and partly in longitudinal section of a bag filling apparatus according to the invention.

FIGS. 25, inol., are similar views illustrative of successive stages of the bag filling operations.

FIG. 6 is a fragmentary showing in elevation of the upper portion of the FIG. 1 apparatus, illustrative of a modified form of infeed duct interconnecting the supply and packer bins.

FIG. 7 is a fragmentary view in elevation of the base portion of the FIG. 1 apparatus, illustrating the addition thereto of a fluidizing air pad and appurtenant components.

FIG. 8 is a further fragmentary detail in elevation of the upper portion of the FIG. 1 assembly, showing the addition to the infeed air duct of a mechanical closure member for purposes hereinafter stated.

Referring to FIG. 1, the apparatus shown comprises a vertical packer or dispensing bin 10 of cylindrical, rectangular or other polygonal cross-section, of a length exceeding its transverse dimension. The bin terminates at its base in a discharge outlet 11, connected through a flexible coupling 12 to a spout 13, which is inserted in the sleeve of a valve sleeve type bag 14, the bag being secured to the spout by a releasable clamp 15. The flexible coupling 12 may be pinched to mechanical closure, as at 16, by means of a releasable clamp 17.

Clamps

15 and 17 may be pneumatically, electrically or otherwise actuated.

A pipe section 20 extends through the sidewall 21 of bin 10, preferably through. the upper half thereof and is connected within the bin to the top of a tubular disseminator 22, of sheet metal, plastic or the like, the cylindrical wall portion of which is provided with a series of holes, as at 23, disposed therealong and thereabout, for disseminating air or other gas injected under pressure into the disseminator via the pipeline 20. The disseminator may be installed in sections, as at 22a, and as thus extended to a desired or required overall length. The disseminator is preferably positioned substantially coaxial with the bin 10 as shown, and its lower end extends down to a level close to that of the discharge outlet 11.

The pipe section 20 terminates exteriorly of the bin 10, in a valve 24, which is positionable for connecting the pipe section 20 either to a pressure line 25 extending to a source of compressed air, or alternatively to an atmosphenic exhaust outlet 26.

The bin 10 is closed off at the top by a cover plate which is centrally apertured, as at 31, for reception of a closely fitting infeed duct 32, which projects into bin 10 below the cover 30, for a substantial distance, as at 33, as discussed below. The infeed duct terminates at its upper end in a tapered base 34, of a supply bin mounted above the packer bin 10 as shown.

In a specific embodiment of the apparatus, operated in accordance with the invention as above described, the packer bin 10 was cylindrical and of diameter 14 inches and height 5 feet. The infeed duct 32 was likewise cylindrical and of a length 12.5 inches, of a diameter 6 inches,

and projected 6.5 inches into bin 10 below the cover 30 thereof. The disseminator 22 was of a length 30 inches and diameter 5 inches. Its lower end was 6 inches above the base of the packer bin. Air was supplied over line 25 at pressure of 10 p.s.i.

Referring nowto FIGS. 25, incl., for a description of the operation of the FIG. 1 apparatus in filling bag 14 with loose aggregate material from the packer or dispensing bin 10, the operating cycle is as follows: Assuming the apparatus initially in the completely empty condition of FIG. 1, the flexible coupling 12 in the packer bin discharge outlet is pinched off by the closure clamp 17, and the valve 24, actuated to exhaust as indicated by the arrow. A supply of the loose aggregate material is changed, as at 50, into the supply bin 35. During the charging the material will fall through the infeed duct 32 into the packer bin 10 until the latter is filled, as at 51. Continued loading will then progressively fill the supply bin 35 with the material, as at 52, this filling being continued until the supply bin is filled to a level 53, such that the hydrostatic head of the material over the area of the infeed ducts is on the order of about -300 pounds, depending on the material. With the apparatus exemplification above given, this would be on the order of about 3-10 p.s.i. over the duct area.

The bin valve 24 is now actuated to connect the disseminator pipeline 20 to the air infeed pressure line 25, as shown by the arrow on FIG. 3, and the bin discharge spout clamp 17, released, as also shown in FIG. 3. The loose aggregate material in the packer bin 10. will thereupon start flowing through the bin discharge outlet 11 and spout 13 into the bag 14, under the combined action 7 of gravity and the flow of air under pressure from the disseminator 22.

The outward fiow of air from the disseminator 22 will be somewhat as indicated by the arrows of FIG. 3. Some will flow downward as shown to facilitate discharge of the loose aggregate through spout 13 of the packer bin; while some of the air will flow upward toward the infeed duct 32 as indicated, tending thereby to prevent further discharge of the aggregate 52 from the supply bin into the packer bin. Due to the combined action of the upsurge of air against the infeed duct and the packing action of the hydrostatic head of the material 52 in the supply bin exerted over the duct areas, the material will bridgeacross the duct passage, as at 55,'and plug the opening, thereby effectively sealing the packer bin against escape through the infeed duct of the pressurized air in the packer bin.

Accordingly as the material 51 in the packer bin continues to discharge through the spout 13 into the bag 14, the level of the material in the packer bin will continue to fall, as at 56, FIG. 3, and thence as at 57 of FIG. 4, at which level the bag 14 is filled to the preselected weight or desired weight. At this stage the clamp 17 is actuated to close off the spout 13 and valve 25 is actuated to connect the disseminator pipeline 20 to the atmospheric exhaust 26, as indicated by the arrow on valve 24, FIG. 5. This releases the air pressure in the packer bin, whereupon the material bridge 55, FIGS. 2 and 3, in the infeed duct 32, collapses, causing the material 52 in the supply bin to flow under gravity through the infeed duct 32 into the packer bin 10, as at 58, thus refilling the packer bin, as shown at 51 in FIG. 2. This cycle of operation is then repeated for each successive bag to be filled.

Referring to FIG. 6, the infeed duct 32, may be provided with a plug 60 of conforming contour and secured to an adjusting rod 61, for vertical up or down' adjustment as indicated by the arrow, the adjustment being such for any given loose aggregate material being packaged, as to establish the optimum infeed aperture for assuring the material bridging action in the duct during discharge of the packer bin.

Referring to FIG. 7, the base of the supply bin may be provided with a fluidizing air pad, mounted at 62 adjacent the bin discharge outlet for purposes above explained, the pad being backed by an air chamber 63, supplied with air under pressure, from line 64, having interposed therein a valve 65, for adjusting the flow being on and ofi or between high or low flow rates, as desired.

Referring to FIG. 8, the infeed duct 32 may optionally be provided with a mechanical closure gate 66, which during the filling cycle is maintained in the open position shown until the material bridge 55 has formed, and may thereupon be closed for the remainder of the packer bin discharge. In this way it is assured that the air seal in the infeed duct will be maintained during such discharge, should the material bridge collapse due to abnormal operation. It will be observed in this connection that the material bridge 55 forms above and is spaced from the gate 66, so that the latter may be actuated without contacting the aggregate material. Hence if this material is of an abrading character or comprises relatively large pellets, no injury to or jamming of the gate can occur in closure, as in the operation of force flow packers as heretofore constructed and operated.

What is claimed is:

1. Apparatus for dispensing and packaging loose aggregate material, comprising: a closed dispensing bin having a lower dispensing outlet and closure means therefore releasable for dispensing said material, a supply bin disposed above said dispensing bin and opening at its base into a duct projecting in sealed relation through a top opening in said dispensing bin, means for injecting air under pressure into at least the upper portion of said dispensing bin and means connected thereto for dispersing said air in said dispensing bin, for dispensing said material from said dispensing bin through said outlet, and said duct being of dimensions and aperture such that during pressurization of said dispensing bin by said injected air, and with said supply bin filled with said material to the extent of forming a static head of material for maintaining a downward force over said duct area of at least one hundred pounds, the said material in said supply bin bridges across and plugs said duct and prevents flow of said material into said dispensing bin.

2.1Apparatus for dispensing and packaging loose aggregate material, comprising: a closed dispensing bin having a lower dispensing outlet and closure means therefor releasable for dispensing said material, a supply bin disposed above said dispensing bin and opening at its base into a duct projecting in sealed relation through a top opening in said dispensing bin, means for injecting air under pressure into at least the upper portion of said dispensing bin and means connected thereto for dispersing said air in said dispensing bin, said dispersing means comprising a tubular disseminator disposed substantially coaxially of said dispensing bin and perforated throughout its length and circumference, for dispensing said material from said dispensing bin through said outlet, and said duct being of dimensions such that during pressurization of said dispensing bin by said injected air, and with said supply bin filled with said material to the extent of forming a static head of material for maintaining a downward force over said duct area of at least one hundred pounds, the said material in said supply bin bridges across and plugs said duct and prevents flow of said material into said dispensing bin.

3. Apparatus for dispensing and packaging loose aggregate material, comprising: a closed dispensing bin having a lower dispensing outlet and closure means therefor releasable for dispensing said material, a supply bin disposed above said dispensing bin and opening at its base into a duct projecting in sealed relation through a top opening in said dispensing bin, means for injecting air under pressure into at least the upper portion of said dispensing bin and means connected thereto for dispersing said air in said dispensing bin, said dispersing means comprising a tubular disseminator disposed substantially coaxially of said dispensing bin and perforated lengthwise and circumferentially, said disseminator being also disposed with its base adjacent said dispensing outlet, for dispensing said material from said dispensing bin through said outlet, and said duct having an aperture area of about 30 to square inches and a length of about 6 to 12 inches, and being of dimensions such that during pressurization by said dispensing air of said dispensing bin by said injected air, and with said supply bin filled with said material to the extent of forming a static head of material for maintaining a downward force over said duct area of at least one hundred pounds, the said material in said supply bin bridges across and plugs said duct and prevents flow of said material into said dispensing bin.

4. Apparatus for dispensing and packaging loose aggregate material, comprising: a closed dispensing bin having a lower dispensing outlet and closure means therefor releasable for dispensing said material, a supply bin disposed above said dispensing bin and opening at its base into a duct projecting in sealed relation through a top opening in said dispensing bin, means for injecting air under pressure into the upper portion of said dispensing bin and means connected thereto for dispersing said air in said dispensing bin, said dispersing means comprising a tubular disseminator disposed substantially coaxially of said dispensing bin and perforated throughout its length and circumference, for dispensing said material from said dispensing bin through said outlet, and said duct being of dimensions such that during pressurization by said dispersing air of said dispensing bin by said injected air, and with said supply bin filled with said material to the extent of forming a static head of material for maintaining a substantial pressure over said duct area the said material in said supply bin bridges across and plugs said duct and prevents flow of said material into said dispensing bin, means for injecting fluidizing air under pressure through the base of said dispensing bin adjacent said dispensing outlet, and releasable, mechanical closure means for said duct.

5. Apparatus for dispensing and packaging fluidizable, loose aggregate material, comprising: a closed bin having a lower dispensing outlet, said outlet having normally closed valve means releasable for dispensing said material, a pressurized gas injection and dispersing means for fluidizing said material, valve means for controlling said injection and dispersing means, said bin having normally closed venting means operable to vent said bin to atmospheric pressure, a hopper containing material therein being positioned adjacent said bin, an infeed conduit interconnecting said hopper with said bin, said conduit being adapted to form a material-gate, plugging said conduit when said air injection and dispersing means are fluidizing said material and when said outlet valve means are released for dispensing said material, said infeed conduit being adapted to pass material therethrough when said air injection and dispersing means are closed and when dispensing outlet means are closed and when said venting means are open.

6. Apparatus for dispensing and packaging fiuidizable, loose aggregate material, comprising: a closed bin having lower dispensing outlet means, pressurized air injection and dispersing means for pressurizing said bin and fluidizing said material, a hopper containing said material positioned above said bin, an infeed conduit interconnecting said hopper with said bin for the flow of said material therethrough, said infeed conduit being provided with a substantially smaller cross-sectional passage area than said bin, said infeed conduit being adapted to form a materialgate therein, plugging said conduit, when a substantial weight of material is contained within said hopper and when said injection and dispersing means are fluidizing said material in said bin.

7. Apparatus for dispensing and packaging loose aggregate material, comprising: a closed dispensing bin having a lower dispensing outlet and closure means therefor releasable for dispensing said material, a supply bin disposed above said dispensing bin and opening at its base into a duct projecting in sealed relation through a top opening in said dispensing bin, means for injecting air under pressure into at least the upper portion of said dispensing bin and means connected thereto for dispersing said air in said dispensing him, said duct being of dimensions such that during pressurization by said dispersing air of said dispensing bin by said injected air, and with said supply bin filled with said material to the extent of forming a static head of material for maintaining a substantial pressure over said duct area, the said material in said supply bin bridges across and plugs said duct and prevents fiow of said material into said dispensing bin, and mechanical closure means for said duct.

8. A method of packaging loose aggregate material, comprising: filling a supply bin to a substantial height with said material, introducing said material from the lower portion of said supply bin into an elongated infeed conduit having reduced passage area, intermittently passing said material from said conduit into a closed dispensing bin having increased passage area, intermittently introducing dispersing air into an elongated central portion of said dispensing bin at a plurality of openings to pressurize said dispensing bin and fiuidize the material in said dispensing bin, while simultaneously causing to form a releasable material-gate within said conduit by pressurization by said dispersing air of said dispensing bin to prevent flow of said material into said dispensing bin, and while simultaneously discharging said fluidized material from said dispensing bin through an outlet opening into a packaging container.

9. A method of packaging loose aggregate material, comprising: filling a supply bin to a substantial height with said material, introducing said material from the lower portion of said supply bin into an infeed conduit having reduced passage area, intermittently passing said material from said infeed conduit into a closed dispensing bin having increased passage area, intermittently introducing dispersing air into said dispensing bin to cause said material in said conduit to bridge across and plug said conduit and substantially prevent fioW of said material into said dispensing bin, thence closing mechanical valve means in said infeed conduit to completely prevent flow of said material into said dispensing bin, and discharging said material from said dispensing bin through an outlet opening into a packaging container.

References Cited by the Examiner UNITED STATES PATENTS 182,097 9/1876 Barton 222373 951,754 3/1910 Buzzell et a1 302 1,271,107 7/1918 Weller 222-493 X 2,032,367 3/1936 Kennedy et al 302-53 2,219,208 10/1940 Knight 222193 2,851,401 9/1958 Payne 30263 X 2,936,994 5/1960 Lau 141'-68 X 3,073,401 1/1963 Zenke.

FOREIGN PATENTS 671,667 5/1952 Great Britain.

LAVERNE D. GEIGER, Primary Examiner.

LOUIS J. DEMBO, Examiner.

D. MAXSON, H. BELL, Assistant Examiners.

Claims

8. A METHOD OF PACKAGING LOOSE AGGREGATE MATERIAL, COMPRISING: FILLING A SUPPLY BIN TO A SUBSTANTIAL HEIGHT WITH SAID MATERIAL, INTRODUCING SAID MATERIAL FROM THE LOWER PORTION OF SAID SUPPLY BIN INTO AN ELONGATED INFEED CONDUIT HAVING REDUCED PASSAGE AREA, INTERMITTENTLY PASSING SAID MATERIAL FROM SAID CONDUIT INTO A CLOSED DISPENSING BIN HAVING INCREASED PASSAGE AREA, INTERMITTENTLY INTRODUCING DISPERSING AIR INTO AN ELONGATED CENTRAL PORTION OF SAID DISPENSING BIN AT A PLURALITY OF OPENINGS TO PRESSURIZE SAID DISPENSING BIN AND FLUIDIZE THE MATERIAL IN SAID DISPENSING BIN, WHILE SIMULTANEOUSLY CAUSING TO FORM A RELEASABLE MATERIAL-GATE WITHIN SAID CONDUIT BY PRESSURIZATION BY SAID DISPERSING AIR OF DISPENSING BIN TO PREVENT FLOW OF SAID MATERIAL INTO SAID DIPENSING BIN, AND WHILE SIMULTANEOUSLY DISCHARGING SAID FLUIDIZED MATERIAL FROM SAID DISPENSING BIN THROUGH AN OUTLET OPENING INTO A PACKAGING CONTAINER.