GB2062590A - Apparatus for assisting the flow of particulate material from a storage hopper - Google Patents

Abstract

Apparatus 10 for assisting the flow of particulate material from a storage hopper H has means 12 for controlling the flow located below the hopper H and comprising a dish- shaped member 16 so positioned so as to be able to receive particulate material from the hopper H, and an associated baffle 44 arranged above a central opening 18 in the dish- shaped member 16 so as to cause the material to flow around the sides thereof and then indirectly into the opening 18. Another means 14 is provided below the opening for controlling the flow of material leaving the opening 18. The other means 14 preferably comprises a further dish-shaped member 22 so positioned so to be able to receive the particulate material from the opening 18 and a further associated baffle 50 arranged above a further central opening 24 in the further dish-shaped member 22 so as to cause the material to flow around the sides thereof and then indirectly into the further opening 24 from which the material is discharged from the apparatus 10. <IMAGE>

Description

SPECIFICATION Apparatus for assisting the flow of particulate material This invention relates to apparatus for assisting the flow of particulate material and in particular for activating the flow of particulate material from a storage hopper, or bin.

Conventional storage bins have large crosssections which converge generally conically to small outlets at the bottom. Most flow problems are caused by materials wedging and compacting into the converging part of the bin. When the bins are full, the enormous weight above compresses the underlying material in the converging or conical part of the bin resulting in severe packing.

An initial and highly commercially successful solution to the above-mentioned problem is shown in United States Patent No. 3 173 583 for Bin Activator which issued Match 16, 1965, to the present Applicant. In this patent, a bin activator formed of a conically shaped member is substituted for the converging conical shaped outlet of a conventional storage bin. A baffle within the conically shaped member relieves the weight of the overhead material and when the entire bin activator is subjected to vibration, the baffle also prevents preferential flow from the centre of the hopper and by sending vibrations into the overhead materials, promotes the materials downward movement into the bin activator and then out through the bin activator outlet.The bin activator is vibrationally isolated from the storage bin thereby permitting large vibrational forces to be applied to the bin activator without the need to be concerned with the size of the storage bin or vibration to surrounding structures.

Although the above bin activator was commercially successful, the present Applicant improved upon the basic invention by providing a substantially flat dish-shaped member in place of the conically shaped member, with a convex baffle mounted within the dish-shaped member. It was found that the dish-shaped member eliminated the compaction that frequently occurred in the earlier conical configuration. The dish-shaped member design was based on the finding that a side outlet in a horizontally vibrated container with a flatter bottom was more effective than a bottom outlet for discharging materials because the direction of disengagement of the particulate material from its stored mass was in the same horizontal direction as the horizontally applied gyrator force.The dish-shaped bin activator incorporates the side outlet concept whilst utilizing a bottom outlet by having the baffle cooperate with the relatively flat floor of the dish to provide a side outlet effect. This results from any vertical bridging between the baffle and the floor of the dish readily responding to the horizontal vibrations.

Such a dish-shaped bin activator generally included a gathering cone at the outlet end. With larger sized bin activators, however, the gathering cone might be five or six feet deep and it sometimes happened that certain materials would accumulate and compact in the gathering cone.

For example, if the downstream take-away rate was substantially and consistently less than the potential discharge rate of the bin activator, accumulation and compaction might result in the gathering cone.

According to the present invention we therefore provide apparatus for assisting the flow of particulate material from a storage hopper wherein means for controlling flow is located below the hopper and comprises a dish-shaped member so positioned as to be able to receive particulate material from the hopper and an associated baffle arranged above a central opening in the dish-shaped member so as to cause the material to flow around the sides thereof and then indirectly into the opening, and wherein another means is provided below the opening for controlling the flow of material leaving the opening.

As a preferred feature, the other means comprises a further dish-shaped member so positioned as to be able to receive the particulate material from the opening and a further associated baffle arranged above a further central opening in the further dish-shaped member so as to cause the material to flow around the sides thereof and then indirectly into the further opening from which the material is discharged from the apparatus.

The baffle and the further baffle are preferably convex in shape and the opening and the further opening are preferably circular. The baffle and the further baffle may be spaced from each other along the hopper axis, the former having an area larger than that of the latter. The opening may be iarger than the further opening, and may have a diameter substantially equal to the baffle, while the further opening may have a diameter substantially equal to the further baffle.

The means for controlling the flow preferably has a cylindrical portion axially spaced from the hopper wall, while the other means has a cylindrical portion secured to the dish-shaped member at the central opening thereof.

In the preferred embodiment means for vibrationally suspending the apparatus from the hopper are provided, together with means for vibrating the apparatus, whereby vibration of the apparatus will further assist material in the storage hopper to flow through the means for controlling flow and the other means for controlling flow and thence to be discharged from the apparatus.

An example in accordance with the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a side elevational view of an apparatus according to the present invention; Figure 2 is a top plan view with certain parts omitted and a portion of the baffle broken away; Figure 3 is an enlarged, fragmentary crosssectional view taken along the line 3-3 of Figure 2; and Figure 4 is a schematic drawing showing the theory of operation of the apparatus of Figure 1.

Referring now to the drawings in detail, wherein like reference numerals indicate like parts throughout the several figures, reference numeral 10 indicates the apparatus of the present invention which is adapted to form the bottom portion of a storage hopper H. The apparatus 10 comprises means for controlling flow 12 and another means for controlling flow 14. The flow controlling means 12 includes a concave or dishshaped member 16 with a central opening 18 and cylindrical portion 20 and the other flow controlling means 14 includes a further concave or dish-shaped portion 22 with a further central opening 24 and a cylindrical portion 26. A discharge member 28 is preferably included at the outlet or central opening 24 of the other flow controlling means 14 to produce the desired discharge flow characteristics.All of these aforementioned parts of the apparatus are preferably welded together to form a rigid, unitary structure which is suspended from the storage hopper H by means of forged steel hangers 30.

The upper ends of the hangers 30 are pivotallycoupled to bracket plates 32 welded to hopper H and the lower ends of the hangers are similarly coupled to bracket plates 34 welded to the flow controlling means 12. The hangers 30 are provided with rubber bushings to provide necessary vertical rigidity while affording a maximum horizontal flexibility for the apparatus when vibrated. The apparatus 10 is vibrated substantially in a horizontal plane by means of an electro-mechanical gyrator 36 comprising an electric motor having a vertical drive shaft carrying one or more eccentrically mounted weights as is well known in the art.The apparatus vibration is isolated from the hopper H by spacing the apparatus 10 from the bottom of the hopper H with an elastic sleeve 38 secured in position by a pair of circular metal straps 40, 42. The elastic sleeve 38 in combination with the hangers 30 ensures that the apparatus 10 is relatively free to vibrate in response to the vibratory thrust forces applied thereto by the eccentrically-mounted weights of the gyrator 36.

There is positioned within each of the flow controlling means a baffle which cooperates with the associated dish-shaped member of the means to move particulate material 1 7 through each said means and into the discharge member 28. In the flow controlling means a baffle 44 is positioned above the dish-shaped member 16 and within the cylindrical portion 20 and is supported by spaced angle-iron bars 46, 48 which extend across the cylindrical portion and are welded thereto.

Although the baffle 44 is generally located within the cylindrical portion 20, it may be extended higher in the storage hopper H depending on the size of the hopper and the type of material therein.

The baffle 44 is of circular convex configuration and has a diameter substantially equal to the diameter of central opening 18 so that material 17 cannot fall directly from the hopper H into the central opening 18. In the other flow controlling means a further baffle 50 is positioned above the further dish-shaped member 22 and is supported by spaced angle iron bars 52, 54 which extend across the cylindrical portion 26 and are welded thereto. The further baffle 50 is of the same but smaller circular convex configuration as the baffle 44 and has a diameter substantially equal to the diameter of the further central opening 24 so that material 1 7 cannot fall directly through the central opening 18 into the further central opening 24.

In operation and with specific reference to Figure 4, the gyrator 36 produces powerful thrusts Y which vibrate the dish-shaped members 16, 22 and the baffles 44, 50 predominantly in a horizontal plane. At the same time, the convex baffle 44 resolves the horizontal thrusts into strong vertical impulses I extending far up into the hopper, thereby discouraging overhead bridging of the particulate material 17. Consequently, the apparatus effectively fluidizes the material 1 7 in the lower portion of the hopper and in the region of baffle 44, thereby resulting in a positive, continuous flow of material 1 7 from the hopper, past the baffle 44 and onto the dish-shaped member 16. The relatively flat slope of the dish prevents material 1 7 from compacting.Material 17 stands as a vertical bridge B between the periphery of the baffle 44 and the floor of the dish as shown schematically in Figure 4 as a column of blocks. The horizontal force A readily disrupts the bridge and discharges the material 1 7 through the central opening 18 into the other flow controlling means 14 past the further baffle 50 and onto the further dish-shaped member 22 where similar cooperation between the further baffle 50 and the further dish-shaped member 22 under the influence of the horizontal force At moves the material 17 out through the further central opening 24 and into the discharge member 28. By making the baffle diameters substantially equal to the central opening diameters, material from the baffles must necessarily fall onto the dish-shaped members where the appropriate horizontal force will continue the movement of the material 17.

The term dish-shaped in this specification is intended to encompass a concave shape which will provide a relatively flat floor to provide a side outlet effect between the bottom of the dishshaped member and the baffle.

Claims (9)

1. Apparatus for assisting the flow of particulate material from a storage hopper wherein means for controlling flow is located below the hopper and comprises a dish-shaped member so positioned so as to be able to receive particulate material from the hopper and an associated baffle arranged above a central opening in the dish-shaped member so as to cause the material to flow around the sides thereof and then indirectly into the opening, and wherein another means is provided below the opening for controlling the flow of material leaving the opening.

2. Apparatus as claimed in Claim 1, wherein the other means comprises a further dish-shaped member so positioned as to be able to receive the particulate material from the opening and a further associated baffle arranged above a further central opening in the further dish-shaped member so as to cause the material to flow around the sides thereof and then indirectly into the further opening from which the material is discharged from the apparatus.

3. Apparatus as claimed in Claim 2, wherein the opening is larger than the further opening.

4. Apparatus as claimed in Claim 2 or 3 wherein the baffle and the further baffle are spaced from each other along the hopper axis, and wherein the baffle has an area larger than that of the further baffle.

5. Apparatus as claimed in any of Claims 2 to 4, wherein the baffle and the further baffle are convex in shape and wherein the opening and the further opening are circular.

6. Apparatus as claimed in Claim 5 as appendant to Claims 3 and 4 wherein the baffle has a diameter substantially equal to the central opening formed in the dish-shaped member, and wherein the further baffle has a diameter substantially equal to the further central opening formed in the further dish-shaped member.

7. Apparatus as claimed in any preceding claim wherein the means for controlling flow has a cylindrical portion spaced from the hopper wall and wherein the other means for;controlling the flow has a cylindrical portion secured to the dishshaped member at the central opening thereof.

8. Apparatus as claimed in any preceding claim, comprising means for vibrationally suspending the apparatus from the hopper, and means for vibrating the apparatus, whereby vibration of the apparatus will further assist material in the storage hopper to flow through the means for controlling flow and the other means for controlling flow and thence to be discharged from the apparatus.

9. Apparatus substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.