US3351391A - Airtight bag packer - Google Patents

Description

Nov. 7, 1967 J. F. GREEN AIRTIGHT BAG PACKEH Filed Feb. 21, 1966 1.. flA 0 4w United States Patent ABSTRACT OF THE DISCLOSURE There is described a bag packer using air to fluidize granular or powdered material in which the material is discharged upwardly through a nozzle positioned within a hopper containing the material, the nozzle propelling the material upwardly through a conduit extending vertically and then bending through 90 and extending horizontally out of the side wall of the hopper. The nozzle is made adjustable by having one element supported by a flexible membrane which also acts as a diffusing pad.

The membrane is deformed to move the nozzle element and change the size of the orifice opening of the nozzle.

This invention relates to bag packers and, more particularly, is concerned with improvements in apparatus for fluidizing solid particulate material with air.

Bag packing machines in which granular or powdered solid materials are mixed and transported by air as the .fluidizing agent are well known. In the conventional air bag packer, the material is placed in an enclosed hopper. The bottom of the hopper is slanted, and the spout is connected to the hopper adjacent the lower bottom edge.

The bottom of the hopper is in the form of a porous pad through which air is directed under pressure. The air mixes with and suspends the solid material and carries the solid material out through the spout into the bag.

The problem with such an arrangement is that the hopper must be above the level of the spout, which presents a problem where limited head room is available. Attempts to arrange the discharge point of the pressurized hopper chamber below the level of the spout have heretofore not been too successful. The discharge from the hopper. and the spout are both horizontally positioned. If they are not at the same level, any conduit interconnecting the discharge nozzle in the spout must have a double reverse bend. However, any bend which restricts the flow of air results in clogging. This is aggravated by the fact that the material mustbe lifted from the point of dischargefrom the hopper up to the level of the spout.

The present invention is directed to an improved air bag packer in which the point of horizontal discharge from the hopper chamber to the horizontal spout need not be locatedat the bottom of the hopper but may be positioned at some intermediate level along the vertical extent of the hopper chamber. This permits the hopper chamber to be lowered in relation to the position of the spout, substantially decreasing the overall height of the bag packing machine. At the same time, by eliminating any conduit with double bends, the hopper may be positioned immediately adjacent the filling spout so as to provide a more compact construction than heretofore has been achieved.

In brief, the invention is directed to an air bag packer in which a hopper for receiving particulate solid material forms a fully enclosed air chamber. A conduit has a horizontal portion extending through the side wall of the hopper, the outer end of the conduit forming a horizontal loading spout for receiving a bag. The conduit curves downwardly within the hopper chamber to form a vertical section which terminates in a nozzle adjacent the bottom wall of the chamber. The nozzle includes two elefi lfidi Patented Nov. 7, 1%67 ments, one element forming a convexly curving surface of revolution contiguous with the internal surface of the conduit, while the second element is supported by the bottom of the chamber and forms a concavely curving surface of revolution extending up into the first element to form therewith an annular orifice. The second element is adjustably spaced from the first element so as to vary the size of the orifice. Air is admitted into the chamber under pressure. The bottom wall of the chamber is preferably in the form of a canvas membrane through which the air is directed into the chamber, the second element of the nozzle being secured to the canvas membrane so that deformation of the membrane causes the movement of the second element toward and away from the first element of the nozzle.

For a more complete understanding of the invention, reference should be made to the accompanying drawing wherein:

FIGURE 1 is a side elevational view of an air bag packer incorporating the features of the present invention; and

FIGURE 2 is a partial sectional view of the nozzle construction in the bag packer of FIGURE 1.

Referring to the drawings in detail, the numeral 10 indicates generally the frame of the bag packer machine. The frame includes four vertical corner posts, two of which are indicated at 12 and 14. The vertical posts are joined by horizontal frame members such as indicated at 16, 18 and 20.

A bag filling spout 22 and lower bag support 24 are rigidly joined by a vertical plate 26 which is supported from the frame 10 by a suitable weighing mechanism (not shown). The weighing mechanism is not material to the present invention and any conventional weighing mechanism, such as that described in connection with Patent 2,866,484, may be used. A bag when placed on the Spent 22 is clamped in position by clamping pad 28 actuated by a hydraulic or other suitable actuating mechanism 30 to prevent the bag from being blown off the spout as it is being filled.

The solid particulate matter, which is to be loaded into bags, is stored in a hopper indicated generally at 32. The hopper is supported by the frame In in any suitable manner with the lower end of the hopper extending down into the frame well below the level of the spout 22. The upper end of the hopper is provided with a closure mechanism indicated generally at 34 which includes a flap valve by which the top of the hopper can be opened or closed. The flap valve includes a pivoted flap member 36, shown in its open position, which can be rotated from a vertical open position to a horizontal closed position, indicated by the dotted lines, after the hopper is loaded with the material to be packed. With the flap valve closed, the hopper 3-2 forms a substantially airtight chamber.

The lower end of the hopper, as best seen in FIGURE 2, is formed with a projecting flange 38. A bottom plate 40 is removably secured to the flange 38 by screws, such as indicated at 42. Clamped between the bottom plate 40 and the flange 38 is a gasket 44 and a membrane made of a canvas pad or other flexible porous material, indicated at 46. An air inlet 48 is provided in the bottom plate 40 which, as shown in FIGURE 1, is connected by a pipe 50 and a valve 52 to a source of air under pressure. When the valve 52 is open, air enters the chamber formed by the hopper 32 through the pores of the canvas membrane 46. Air under pressure may be also admitted to the chamber formed by the hopper 32 through an upper air inlet 54 through a valve 56.

According to the present invention, the material in the hopper 32 is conveyed to the spout 22 through a conduit 60 which passes horizontally out through the wall of the hopper 32 in alignment with the spout 22. A suitable valve 62 is provided in the conduit between the hopper 32 and spout 22 to control the flow of material out through the spout. The conduit 60 within the hopper 32 is formed in a large radius 90 bend 64 into a downwardly extending vertical section 66 which terminates adjacent the bottom of the hopper chamber in a nozzle assembly indicated generally at 68.

As best seen in FIGURE 2, the nozzle assembly includes an upper nozzle element 7 ti and a lower nozzle element 72. The upper nozzle element 70 provides a convexly curving surface of revolution 74 which is contiguous with the interior of the vertical section 66 of the conduit 60. Thus the upper element 70 of the nozzle 68 forms a flaring mouth to the conduit 60. The lower element 72 of the nozzle has a concave curving surface of revolution 76 which projects upwardly from the surface of the canvas path 46 into the flaring opening formed by the upper nozzle element 70. In this manner, the upper and lower elements of the nozzle combine to form an annular opening or orifice from the interior of the hopper 32 into the lower end of the conduit 60.

The shape of the surfaces 74 and 76 are such that the cross-sectional area of the opening decreases in going from the chamber into the conduit. Thus a convergent nozzle is formed which imparts an increase in velocity to air as it passes through the nozzle into the conduit.

In order to handle different materials in which the particles vary in size and density, it is necessary to provide a different entranee-to-throat ratio in the nozzle. In the past this has been accomplished by selecting different nozzles depending on the material to be handled. The present arrangement provides an adjustment between the upper and lower nozzle elements such that the entrance-to-throat area ratio can be readily changed. To this end, an adjusting screw 7 8 is threaded through the bottom plate 40 and presses against the bottom of the lower nozzle element 72 and supporting canvas pad 46. By screwing the adjusting screw 78 in and out, the canvas pad is deformed and the lower nozzle element 72 can be positioned closer to or further away from the upper nozzle element 70 to provide a full range of entrance-to-throat ratios.

From the above description, it will be recognized that an improved air bag packer is provided. The two element nozzle arrangement with the conduit extending upwardly from the bottom of the hopper chamber to an intermediate point on the wall of the hopper where it passes outwardly in a horizontal direction to the spout, permits a much more compact design with greatly lowered overhead requirements than previous designs. The two element nozzle arrangement also provides for adjustment of the entranceto-throat ratio to permit the bag packer to be used with a wide range of different materials. The bag packer may be used with large pelletized materials, for example, by admitting air in through the upper valve 56 and inlet 54 rather than admitting air through the lower valve 52 and inlet 50. In this case, downward movement of the air impinges upon the larger material particles imparting suflicient momentum to move the mass of material into the orifice of the nozzle and out the conduit. For finely divided material, of course, the air admitted through the lower valve 52 and inlet percolates through the canvas pad and agitates the material into a state of suspension so that it can pass through the nozzle and up through the conduit when the valve 62 is open.

What is claimed is:

1. In a bag packer in which solid particulate material is delivered out of a horizontal spout into a bag, the combination comprising a fully enclosed hopper for receiving the material, a delivery conduit including a vertical section within the hopper curving into a horizontal section extending outwardly through the wall of the hopper, means coupling the horizontal section to the spout, the lower end of the vertical section flaring outwardly adjacent the bottom of the hopper, means for admitting air under pressure into the enclosed hopper including a porous fabric pad across the bottom of the hopper and means for applying air under pressure to the outside of the fabric pad to permit air to diffuse into the interior of the hopper, means defining a surface of revolution having a base mounted on the pad and having a tapered point projecting toward the flared lower end of the delivery conduit to form a nozzle, and adjustable means for deforming the pad to move the nozzle forming means toward and away from the lower end of the conduit to change the size of the nozzle orifice.

2. Apparatus for transmitting solid particulate matter by a stream of air or other gaseous fluid, comprising means forming a fully enclosed chamber, the particulate matter being loaded into the chamber, the chamber having a bottom wall, a conduit extending into the chamber and having a vertical portion extending downwardly in the chamber toward the bottom wall, means forming a converging nozzle at the lower end of said vertical portion of the conduit, said nozzle means including a first element forming a convexly curving surface of revolution contiguous with the internal surface of the conduit and a second element supported by the chamber forming a concavely curving surface of revolution positioned to extend up into the first element to form an annular orifice therewith, and means for admitting gaseous fluid under pressure into the chamber, the bottom of the chamber including a porous flexible pad, the second element of the nozzle being mounted on and supported by the pad, said gaseous fluid being admitted into the chamber through said pad.

References Cited UNITED STATES PATENTS 2,707,132 4/1955 Baresch 302-53 3,258,041 6/ 1966 Lau 30229 FOREIGN PATENTS 260,677 1/ 1964 Australia ANDRES NIELSEN, Primary Examiner,

Claims (1)

1. IN A BAG PACKER IN WHICH SOLID PARTICULATE MATERIAL IS DELIVERED OUT OF A HORIZONTAL SPOUT INTO A BAG, THE COMBINATION COMPRISING A FULLY ENCLOSED HOPPER FOR RECEIVING THE MATERIAL, A DELIVERY CONDUIT INCLUDING A VERTICAL SECTION WITHIN THE HOPPER CURVING INTO A HORIZONTAL SECTION EXTENDING OUTWARDLY THROUGH THE WALL OF THE HOPPER, MEANS COUPLING THE HORIZONTAL SECTION TO THE SPOUT, THE LOWER END OF THE VERTICAL SECTION FLARING OUTWARDLY ADJACENT THE BOTTOM OF THE HOPPER, MEANS FOR ADMITTING AIR UNDER PRESSURE INTO THE ENCLOSED HOPPER INCLUDING A POROUS FABRIC PAD ACROSS THE BOTTOM OF THE HOPPER AND MEANS FOR APPLYING AIR UNDER PRESSURE TO THE OUTSIDE OF THE FABRIC PAD TO PERMIT AIR TO DIFFUSE INTO THE INTERIOR OF THE HOPPER, MEANS DEFINING A SURFACE OF REVOLUTION HAVING A BASE MOUNTED ON THE PAD AND HAVING A TAPERED POINT PROJECTING TOWARD THE FLARED LOWER END OF THE DELIVERY CONDUIT TO FORM A NOZZLE, AND ADJUSTABLE MEANS FOR DEFORMING THE PAD TO MOVE THE NOZZLE FORMING MEANS TOWARD AND AWAY FROM THE LOWER END OF THE CONDUIT TO CHANGE THE SIZE OF THE NOZZLE ORIFICE.

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