US2774516A - Apparatus for weighing and packaging powder or granular material - Google Patents

Description

Dec. 18, 1956 JENSEN 2,774,516

APPARATUS FOR WEIGHING AND PACKAGING POWDER OR GRANULAR MATERIAL Filed D80. 13, 1955 2 Sheets-Sheet 1 I00 5 v I 39 I I4 3 I 130 4 X 3W5 T (TH W L u hi LT FIG.|

ATTORNEY S Dec. 18, 1956 E. JENSEN 2,774,516

APPARATUS FOR WEIGHING AND PACKAGING POWDER OR GRANULAR MATERIAL Filed Dec. 13, 1955 2 Sheets-Sheet 2 INVENTOR EJLER JENSEN g @ZZMM M ATTORN Y United States Patent APPARATUS FOR WEIGHING AND PACKAGENG POWDER 0R GRANULAR MATERIAL Ejler Jensen, Copenhagen, Denmark, assignor to F. L. Smidth & (10., New York, N. Y., a corporation of New Jersey Application December 13, 1955, Serial No. 552,907

6 Claims. (Cl. 222-195) This invention relates to apparatus for packaging predetermined quantities of bulk material of a pulverulent nature, and is more particularly concerned with machines for simultaneously filling a plurality of bags with predetermined unit quantities of material from a bulk source.

in packaging such materials as cement, calcined aluminum oxide, and other materials, which can be made fiuent by aeration, it is customary to employ automatic packing apparatus, which receives the fluidized material from a bin or like container and discharges a predeterined quantity of the material in each cycle of operation. In some installations, a plurality of such packers are supplied from a single source and, for this purpose, the material issuing from the bin enters a substantially hori zontal container, such as a tube, which has outlets controlled by the respective packers. The material in the bin is fluidized by introduction of air into it and air is also introduced into the material in the tube to maintain the aeration of the material.

The rate of discharge through the outlets depends on the pressure of the material and this pressure depends on the head of material in the bin and the resistance to the movement of the material from the bin to the outlets. Since the distributing tube is generally quite long in relation to its width, there is a noticeable pressure drop from the bin to the outlet farthest removed therefrom, so that the bag receiving material at that outlet is filled more slowly than the other bags. As the apparatus is ordinarily automatic or semi-automatic in operation, the rate of discharge at the outlet farthest from the bin determines the length of a cycle of operation and the output of the apparatus can thus be increased by increasing the rate of discharge through the most remote outlet.

The present invention is directed to the provision of a weighing and packing machine of the type described, which is provided with novel means for distributing the material with an increased pressure of the material at the outlets and thus increasing the rate of discharge of the material and the output rate. The. new distributing means is of simple construction and produces the desired results at little expense.

For a better understanding of the invention, reference may be made to the accompanying drawings, in which:

Fig. l is an elevational view of the new packaging system with parts broken away;

Fig. 2 is an elevational view of a second form of the new apparatus with parts broken away;

Fig. 3 is an elevational view of another form of the apparatus with parts broken away; and

Fig. 4 is an enlarged cross-sectional view taken on lines 4-4 of Fig. l.

The new system includes a supply bin holding a bulk supply of powdered material 11, which may be cement or like material capable of being fluidized. The bin 10 has a discharge outlet 12 communicating with an elongated horizontally disposed distributing tube 13 at one end of the latter. The tube 13 is ordinarily of con- 'ice siderable length as compared to its width and it is made up of a plurality of connected sections 13a.

The bin has a hopper bottom 10:: and is provided with means for introducing air into the material to render it fluent. For this purpose, the bottom may be formed with a porous inner Wall 14 spaced from the outer wall of the bottom and, with the latter, defining a chamber, to which air is supplied through pipe 15 for diifusion through wall 14 into the material. The fluidizing air, which passes upwardly through the material 11, leaves the bin 10 through a suction pipe 16.

A plate 17 of air-permeable material is mounted in an opening in the wall of each section 13:: of tube 13 and a domed plate 18 covers the plate 17 and forms an air chamber for receiving air under pressure from a pipe 19. Air entering the tube 13 through plates 17 maintains the aeration of the material traveling through the tube. A rotary agitating device is mounted within tube 13 and comprises a shaft 20 supported in bearings at the ends of the tube and carrying radial arms 2%. The shaft is driven by a motor 21 at one end and the device keeps the material constantly in motion and insures its proper flow through the tube.

Each section 13a of the distributing tube 13 has an outlet opening 22 and a fitting 23 is mounted on the tube at each opening and supports a tube 23:: of resilient material, which projects into the upper end of a filling spout 24. The spout is carried by an arm 24a pivoted on a frame 25 attached to the lower end of a rod 25a suspended from the beam of a weighing mechanism indicated at W. T he lower end of the filling spout 24 is so shaped that a bag B may he slipped over it in the filling operation.

The tube 23a leading from each outlet of tube 13 is closable by a push rod 26 mounted in a bracket 27 attached to the tube section 13a adjacent the outlet and having a roller 26:: at its inner end, which i engageable with the tube 23a to pinch it against a fixed part of the fitting 23 to close the tube. An arm 23 is pivoted on the outer end of the push rod and has a shoulder on its under surface, which is engageable with a projection on a stud 29 mounted on the lower end of a lever 36. The lever is pivoted on a bracket 31 attached to tube section 13a and carries a roller 32 at its upper end engageable with a cam 33 on a shaft 34. A spring 35 having one end attached to tube 13 and its other end attached to lever 30 tends to swing lever 30 clockwise to hold its roller 32 against the surface of cam 33. A lever as pivoted on bracket 27 has a weight 36a at one end and its other end is engageable with arm 28 beyond the shoulder thereon. Springs (not shown) act on the respective push rods 26 and urge them to cause their rollers 26a to close their tubes 23a.

In the operation of the apparatus described, the bags B are mounted on the lower end of filling spouts 24 and, as the high arc of each cam 33 engages the roller 32 on the associated lever 39, the lever is swung counter-clockwise, and the projection on stud 29 engaging the shoulder on arm 28 moves the arm and push rod 26 to the right to free roller 26a from the resilient tube 23a controlled thereby. The flow of material through tubes 23a into the bags is thus started and, at this time, each frame 25 is held in elevated position in the usual way be a Weight on the scale beam of a weighing mechanism W. When the predetermined weight of material enters a bag B, the frame 25 supporting the filling spout entering that bag descends and this permits the lever 36 to swing counterclockwise and raise arm 28, so that the projection on stud 29 is freed from the shoulder on the arm. The spring acting on push rod 26 then moves the rod to the left, so that its roller 26a compresses tube 23a and shuts off the llow of material to the filled bag. When the low point on a cam 33 moves beneath its roller 32, the lever 36 may be swung to permit arm 28 to move down, so that the projection on stud 29 lies in position to engage the shoulder on arm 28. When the high are of the cam passes beneath roller 32, lever 30 is swung counterclockwise and push rod 26 is moved to disengage its roller 2611 from tube 23a and permit the flow of material to start again.

In the apparatus described, the duration of a cycle of operations is determined by the rate at which the material can be supplied through the outlets 22 to fill the bags and the time of the cycle thus depends on the pressure of the material at the outlet farthest removed from the bin 10. In order to utilize the pressure of the material at the outlets along tube 13 and thereby equalize the time required to fill the bags, the filling apparatus of the invention includes a riser pipe 37, which is connected to the end wall of the distributing tube 13 at the point remote from the bin and extends upward to a height approximately equal to the height of the level of the fluidized material within the bin. The upper end of the pipe is connected by a pipe 38 to the top of the bin and, as the fluidized material flows through the distributing tube 13, it will rise in pipe 37 to a level approximately equal to that of the material in bin 10. The system is similar in many respects to a U-tube with the fluidized material seeking its own level in the vertical legs of the system and being subjected to a uniform pressure from one end of the tube 13 to the other.

To insure that the material in the riser pipe 37 is maintained in a fluid state, an air supply pipe 39 enters the side wall of the riser pipe near its lower end and extends upwardly in concentric relation to a point near the top of the riser pipe. The pipe 37 is perforated throughout the portion of its length within the riser pipe 35 and is wrapped with a material, such as canvas, which will properly distribute the air as it flows from pipe 39 into the riser pipe 37.

The form of the new apparatus shown in Fig. 2 includes a supply bin 40, which has means to fluidize the powdered material therein and is connected to an elongated distributing tube 41 between the ends of the tube. The tube 41 is made up of a plurality of sections 41: each having a discharge outlet controlled by a weighing mechanism W. At the opposite ends of the tube 41, riser pipes 43 extend upwardly approximately to the level of the material in the bin and their upper ends are connected by pipes 44 to the upper end of bin 40. To maintain the material in the riser pipes 43 in a fluidized condition, the central portions of the pipes are perforated and surrounded by jackets 4-5. Air under pressure is introduced into the jackets 45 through air supply pipes 46 and the air then passes through the perforated Walls of the risers 43 and enters the material therein.

In the system of Fig. 3, a single distributing tube 50 made up of sections 50a communicates at opposite ends with supply bins 51, 52, so that there is a flow of material from the ends of the tube toward its center. In this system, a riser pipe 53 extends upwardly from the middle section of the tube 50 and communicates at its upper end with one of the bins 51, 52 through a pipe 54. The arrangement is such that the column of fluidized material maintained in the riser pipe 53 acts to equalize the pressure in the distributing tube 50 by increasing the head at the middle of the tube, which is the part most remote from the bins 51, 52. The riser pipe 53 is provided with an aerating pipe 55 to maintain the material in a fluidized state, and has an overflow pipe 56 near its upper end, through which the material may be discharged if the pressure column becomes too high. Suitable means (not shown) may be provided to convey the material from the discharge end of overflow pipe 56 back to the bins 51, 52.

In the new system, the simultaneous filling of a plurality of receptacles may be more efficiently carried out than has been possible heretofore, since the pressureequalizing riser pipes insure more uniform flow of material to the several outlets of the distributing tube and a reduction in the length of the filling cycle. The use of one or more riser pipes at remote portions of the distributing tube is also eifective in preventing air pockets from forming in such portions of the tube and preventing flow of the material. Another advantageous feature of the invention is that it may be readily incorporated in conventional systems now in use.

I claim:

1. In apparatus for weighing and packaging pulverulent material, the combination of a supply bin for the material and having means for maintaining the material in a fluidized condition, an elongated distributing tube connected to the discharge outlet of the supply bin, a plurality of discharge means leading from the distributing tube at longitudinally spaced points, and a riser pipe extending upwardly from the tube at a point remote from the supply bin for equalizing the pressure head of fluidized material flowing to the discharge means.

2. The apparatus of claim 1, in which the bin is connected to the tube near one end thereof and the riser pipe communicates with the tube near its other end.

3. The apparatus of claim 1, in which the supply bin is connected to the distributing tube intermediate its ends and riser pipes are connected to the opposite ends of the tube.

4. The apparatus of claim 1, in which there are supply bins connected to the tube at its opposite ends, and the riser pipe is connected with the tube intermediate its ends.

5. The apparatus of claim 1, in which there are means to introduce air into the interior of the riser pipe to maintain the material therein in a fluidized condition.

6. The apparatus of claim 5, in which a suction pipe leads from the supply bin to remove fluidizing air therefrom, and a pipe connects the upper end of the riser pipe and the bin to remove fluidizing air from the riser pipe.

No references cited.

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