US2795389A - Apparatus for filling powdered materials into containers - Google Patents

Description

June 11, 1957 P. c. AUST 2,795,389

APPARATUS FOR FILLING POWDERED MATERIALS m'ro con'mmsxs Filed lay 11 1953 s Sheets-Sheet 1 7' INVENTOR PAUL c. Aus'r ATTO NEY June 11, 1957 P c, u s-r APPARATUS FOR FILLING PO Filed Kay 11.. 1953 MATERIALS INTO CONTAINERS WDERED 3 Shats-Sheet 2 A INVENTOR PAUL c. AUST ATTORNEY June 11, 1957 P. c. AUST 2,795,389.

APPARATUS FOR FILLING P OIDERED MATERIALS INTO CONTAINERS Filed Bay 11, 1953 3"S'heets-Sheet 3 WJFIE EI- INVENTOR PAUL c; AUST ATTORNEY United States Patent- APPARATUS FOR FILLING POWDERED MATERIALS INTO CONTAINERS PauliC; Aust, MissionSan Jose, Calif., assignor to Food Machinery andChemical Corporation, San Jose, Cali, acorporation of Delaware Application'May 11, 1953, Serial No. 353,931

1 Claim. (Cl. 249-60) The present invention relates to methods of and apparatus for filling powdered or granularmaterials into suitable containers, such as bags offabnic or paper.

' It' is an object of the present invention to provide a simple and effective method of, and apparatus for, packing powdered or granular materials into containers.

Another object is to provide a method of, and apparatus for, tightly filling bags with powdered or granular materials" without employing mechanical compression means of any kind.

Another object is to provide a fast and eificient method of packing troublesome powdered or granular materials into containers.

Still another object is to provide method, of the type referred to, that is efiective to pack more powdered or granular material into a space of given size than previously possible, even when positive compression means were employed.

An additional object is to provide a method of packing powdered or granular materials. into containers that permits maintaining the amount of material filled into the containers within closer limits than was previously possible.

A further object is to provide a method of packing powdered or granular materials into paper bags without running the risk of exploding the bags, such as occurred when positive means were employed to force the materials into the bags.

In accordance with the invention, the powdered or granular material is fluidized by means of a gaseous fluidizing medium, such as air, before and as his filled into the container. It has been found that powdered or granular materials while in a fluidized condition flow rapidly from the fluidizing chamber into the container without, or with a minimum of, lump formation and without danger of clogging the filling spout. Moreover, powdered or granular materials filled into bags while in a fluidized condition pack at much higher bulk densities than can be accomplished'by ordinary filling methods, including those employing positive means of compression such as auger impellers. Hence, a firmer and more easily handled package results and smaller bags can be used to package a given weight of material. Furthermore, when filling powders or granular materials in fluidized form into containers, as taught by the present invention, much higher weighing accuracies may be obtained than in arrangements employing movable feed means such as angers,

because the flow of fluidized powder may be interrupted as easily and as instantaneously as the flow of a liquid. As an added advantage, it has been found that in the practical performance of the process of the invention, there is far less dust formation in. the space surrounding the filling apparatus of the invention than previously encountered around filling machines, and whenever paper bags are filled with powdered orgranular materials, in accordance with the invention-there is no danger that the bags may explode, such as occurred all too frequently when posi- Patented June 11, 1957 I thebags were employed. The advantages of' the present invention are particularly striking when the method of the invention is applied to powders that are sluggish and do not ordinarily flow freely. The same is true for very heavy powder such as would clog angers, and for sticky powders that tendto bridge over augers.

As an additional advantage the method of filling powdered or granular matenials into containers in accordance with the present invention requires no power driven movable components to advance the material and as a result thereof, the apparatus of the invention is simpler and less costly in construction than powder filling equipment at present in use. Also, there is practically no wear and'no maintenance expense, whereas known filling apparatus are subject to frequent breakdown due to the fact that .the dust developed during the filling operation penetrates. into the bearings of their movable components where itcauses excessive wear and may eventually bring the whole operation to a halt.

The above mentioned objects of the invention and other objects and advantages thereof will be apparent from the following description and the accompanying drawings which illustrate a preferred embodiment of the invention and wherein:

Fig. 1 is a perspective of a bag filling apparatus embodying the invention.

Fig. 2 is a vertical seteion through the fluidizing cham ber of the apparatus illustrated in Fig. l.

Fig. 3 is an enlarged perspective of the lower half of the apparatus viewed from a different point than Fig. 1.

Fig. 4 is a fragmentary plan view of a horizontal section through the fluidized chamber taken along line 44 of Fig. 2.

Fig. 5 is a detail view illustrating the mechanism for cutting off the flow of powdered material from the fluidizing'chamber.

Fig. 6 is another detail view showing part of the mechanism illustrated in Fig. 5 as viewed from a direction at right angles to the direction from which said mechanism is viewed in Fig. 5.

Having reference to Fig. 1, the filling apparatus embodying the present invention comprises a tall cylindrical tank 10 that is mounted upon a suitable pedestal 12 and which is provided at its lower end with a discharge spout 14. In addition the apparatus comprises mechanism 16 that holds a bag 18 with its filling opening 20 over the discharge spout 14 and which is adapted to close the spout and terminate the flow of fluidized powder as soon as the weight of the material delivered into the bag reaches a predetermined upper limit.

A worm conveyor 22 may be arranged to deliver the powdered material from a suitable hopper (not shown) into the cylindrical tank through an aperture 24 provided in the ceiling 26 of said tank, while compressed air from a suitable source (not shown) is introduced into the tank 10 at the bottom end thereof through a plurality of injection nozzles 28 that protrude from a manifold 30 below the floor 32 of the tank through said floor into the interior of the tank, as best shown in Fig. 2. Said manifold 30 may be provided with a master valve 34 and a pressure meter 36, and each of the nozzles 28 may have their individual control valves 38. T o distribute the air jets introduced through the nozzles 28 uniformly over the interior of the tank, a circular pad 40 of canvas or similar porous fabric may be arranged a limited distance above the nozzles 28 as likewise shown in Fig. 2 wherein such a pad is held between collars 42 and 44 that are suitably secured to the inner wall of the cylindrical tank, and wherein said pad is supported on a number of channel bars:46, 48 and50. To permit the air delivered-into the tank 1.0 to escape, a suitable aperture 54- may be "received within an arch 60 bolted to the ceiling 26 and a 1 cross bar 61 disposed within and suitably supported from said arch.

By appropriately controlling the velocity of the air g currents injected into the tank through the nozzles 28 depending upon the fineness and the specific weight of the powder to be packed, the powder within said tank,

.while permitted to drop from the ceiling to the bottom of said tank, may be held in a suspended condition closely resembling a liquid. 7 r

The hereinbefore mentioned discharge spout 14 near the bottom of the tank may be formed by an arcuate plate 62 that is bolted in an airtight manner over a suitable aperture 64 in the side wall of the tank and which forms a short tubular projection 66 extending in a direction tangentially of the cylindrical side wall, 67 of the tank. Drawn over and securely fastened to said projection 66 is a short tube 68 of resilient material, such as rubber, within the free end of which is received a suitable filling nozzle 70. An additional air nozzle 72 (Figs. 2 and 4) may be arranged to direct an air jet .into the tubular projection 66 and push the powder in fluidized condition from the interior of the tank through the spout 14 and into the bag 18 held over the filling nozzle thereof (Fig. 1). Said nozzle 72 may be supplied with air from the common manifold 30 through a short pipe 74 that extends through the arcuate plate 62.

The mechanism 16 for supporting a bag'in proper filling position and for terminating the flow of powdered material into said bag whenever the proper filling weight has been reached, comprises a frame 76 having transversely spaced vertical side bars 78a and 78b from the lower portions of which is adjustably supported a'suitable platform 30. Said frame rests with shoulders 82 and 82b provided on the outer faces of said bars upon the upper ridges of triangular bearing blocks which are secured to the ends of an open stirrup 86 formed at one end of a scale bar'88. Said scale bar turns on a transverse spindle 90 that is mounted in uprights 92a and 92b of a special pedestal 94, and from the opposite end' of said scale bar is supported a counterweight 96 in such a manner that its position longitudinally of said bar may be adjusted so as to vary its effective pull on said bar.

During practical performance of the machine, the

operator places a bag upon the platform 80, pushes its lateral filling snout 20 over the filling nozzle 70 and t lowers a suitable clamp 98 upon the snout so as to hold it dependably over and on to said nozzle.

The mechanism for terminating the flow of fluidized powder from the tank 10 at the appropriate moment comprises a bar 100 that extends transversely across the hereinbefore described resilient center portion 68 of the discharge spout 14 and which is pivotally supported be tween a pair of legs 102a and 102b that rise from and are bolted to a shelf 104 which is rigidly supported from the pedestal 94 and which extends below the resilient center portion of the spout within the vertical plane 'of pedestal 94, while the other end of said actuating lever is formed into a handle 114 that is positioned adjacent the right side bar 78b of the supporting frame 76 within convenient reach of an operator attending to the machine. 7 5

The free end of bar 100 moves in a vertical guide slot 116 (Figs. 5 and 6) provided in a plate 118 that is rigidly supported from the shelf 104 and a strong spring 120 tensioned between the guided end of bar 100 and a suitable point of pedestal 94 below the shelf 104 yieldably urges the bar into the substantially horizontal position shown in broken lines in Fig. 5, which is determined by engagement of said bar 100 with the lower end of the guide slot 116. In said position, the bar 100 presses, through the urgency of the spring 120, a shoe 122 pivotally supported from its lower edge against the yieldable center portion 68 of the spout 14 at a point intermediate of two tubular members 124 and 126 that are mounted upon the shelf 104. The resultant deformation of the yieldable spout portion 68 effectively closes the powder discharge conduit formed by said spout. When the operator depresses the handle 114 of the actuating lever 110, however, the lug 108 projecting from the outer face of said lever comes against a nut 128 provided on the free lower end of the link 106 and pulls said link downwards which is effective to swing the bar 100 in clockwise direction as viewed in Fig. 5 against the urgency of spring means into the position shown in full lines in said Fig. 5. As said bar slides with its guided end within the slot 116 toward the upper end thereof, it comes against the nose 130 of a detent 132 that is pivoted to the plate 118 above said slot 116 (Fig. 6), and cams said detent out of its way against the force of a spring 134 which operates to urge the detent into a position wherein it overlaps the slot 116. Hence, when the upwardly moving bar 100 has passed the detent 132, said detent snaps into position behind the bar 100 and securely latches said bar in raised condition as shown in full lines in Fig. 5. In said raised condition, the pressure exerted by shoe 122 upon the yieldable portion of the spout is sufficiently released to permit flow of a fluidized powder through the spout 14.

As the bag on the platform 80 is filled with'the powder fluidized in, and escaping from, the tank 10, it gets heavier and heavier until it reaches a weight equal to the pull of the counterweight 96 on the opposite arm of the scale bar 88, and said bar begins to swing in counterclockwise direction as viewed in Fig. 3. Located directly above the upper edge of said last mentioned arm when in its idle position is the actuating arm 138 of a normally open switch 140, which is supported from the pedestal 94; Said switch 140 is located in the power circuit of a solenoid 142 that is supported from the guide plate 118 adjacent its slot 116. The armature of said solenoid engages a tail 144 formed on the detent 132, and upon energization of the solenoid, it swings said detent in counterclockwise direction as viewed in Fig. 6 withdrawing its nose 130 from underneath the guided end of a locking bar 100. The bar, therefore, follows the urgency of spring 134 and returns instantaneously to the horizontal position shown in broken lines in Fig. 5 wherein the flow of fluidized powder through the spout 14 is interrupted. Thus, the bag on the platform 80 is filled with precisely its predetermined quantity of powder, and may be taken from the platform 80 upon release of the retaining clamp 98.

For best performance, i. e., for rapid flow, I have found it advantageous to establish a fluidized mass of considerabledepth in the tank 10. In carrying out the process of my invention, to fill burned magnesiaof a fineness passing through a 20 mesh screen into paper bags, at cylindrical tank 30 inches in diameter and 91 /2 inches in height was employed and air was injected into said tank through five air injection nozzles 28 symmetrically arranged on the floor of the tank, and one lateral air injection nozzle 72 under five pounds of pressure per square inch, which introduced eight cubic feet of air per minute into the tank. A column of fluidized mass about 77 inches high was maintainedin the tank, When directing the fluidized mass of magnesia within the tank 10 through the spout 14 into a paper bag on platform 80, it packed into a mater ially lesser volume within said bag than the volume formerly occupied by the same weight in the same bag when the bag was filled according to conventional filling methods. None of the bags filled with the apparatus of the invention exploded, there was at no time any interruption of the filling process due to clogging. The required weight was filled into the bags in a very short time, and formation of dust around the bags was surprisingly low.

While I have described my invention with the aid of a particular embodiment thereof, it will be understood that I do not wish to be limited to the specific constructional details of the apparatus shown and described which may be departed from without departing from the scope and spirit of my invention.

I claim:

Apparatus for packaging predetermined quantities of powdered or granular material into bags comprising, in combination, a housing, a substantially horizontal discharge spout adjacent the lower end of said housing, a conveyor at the top end of said housing for introducing the material into the interior thereof, a plenum chamber extending completely across the bottom of said housing, a porous canvas membrane forming the upper wall of said plenum chamber and separating said plenum chamber from the remainder of said housing, means connected to said plenum chamber for introducing a gaseous fluidizing medium thereto at a velocity adapted to fiuidize the powdered material in said housing above said membrane, an opening in the upper end of said housing for permitting escape of said gaseous fluidizing medium, a mechanism for removably holding a bag in material-receiving position relative to said spout, a continuous weighing scale mechanism for supporting the bag, and a closing arrangement operable to block said spout upon accumulation of a predetermined weight of material within the bag.

References Cited in the file of this patent UNITED STATES PATENTS 862,231 Bates Aug. 6, 1907 1,713,023 Bushmen et al May 14, 1929 1,971,852 Goebels Aug. 28, 1934 2,167,416 Carlson July 25, 1939 2,181,756 Cook Nov. 28, 1939 2,319,192 Sheldon May 11, 1943 2,353,346 Logan July 11, 1944 2,359,029 Goldberg Sept. 26, 1944 2,509,985 Morrow May 30, 1950 2,589,968 Schemm Mar. 15, 1952

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