GB2174372A

GB2174372A - Discharge pot arrangement

Info

Publication number: GB2174372A
Application number: GB08514942A
Authority: GB
Inventors: John Weatherhead
Original assignee: METALAIR Ltd
Current assignee: METALAIR Ltd
Priority date: 1985-04-16
Filing date: 1985-06-13
Publication date: 1986-11-05
Also published as: GB8514942D0; GB2174372B

Abstract

A discharge pot arrangement for use in or on a vehicle carrying powdered or particulate material comprises a downwardly-tapering discharge pot (2a) having a lower exit orifice (26) and at least one tube extending across the discharge pot and supplied with air under pressure, the tube having a plurality of exit orifices (42) at spaced intervals along it. These orifices are associated with one or more cover flaps (56) arranged so that, in the absence of any air flow from the orifices, they close the orifices and are forced away from the orifices when air under pressure is supplied to the interior of the tube. The tube may be of triangular cross-section, and the flaps, of rubber or plastics, may be held in place by glue, rivets or a clamp. <IMAGE>

Description

SPECIFICATION Discharge pot arrangement This invention relates to a discharge pot arrangement for static use e.g. in manufacturing plants, or for use in or on a vehicle carrying powdered or particulate material within a tank.

It is customary with such vehicles for the powdered or particulate material to be discharge by air-entrainment. Such vehicles normally have one or more discharge pot arrangements at the underside of the tank or container.

According to the present invention, there is provided a discharge pot arrangement for powdered or particulate material which can be discharged by gravity or air-entrainment, the arrangement comprising a downwardly-tapering discharge pot having an exit orifice for the material at or near its lower end, at least one tube extending across the discharge pot, and there being an air entry opening at the other end, the tube having a plurality of air exit orifices at spaced intervals therealong, these orifices being associated with one or more cover flaps, the flaps being arranged so that absent any air flow from the orifices they close the orifices under the influence of gravity and are forced away from the orifices when air under pressure is supplied to the interior of the tube.

In a preferred embodiment of the invention, the tube has a cross-sectional shape such that passage past it of descending powdered or particulate material is facilitated. In particular, it may be of triangular cross-section with the vertex upwardly, or of oval cross-section with the major axis of the ellipse substantially vertical, or of polygonal cross-section having two sloping sides meeting at an upwardly-pointing vertex, or other shape which achieves the same result.

Preferably the flap or flaps are of natural or synthetic rubber or a flexible and waterproof synthetic plastics material. The flaps over the orifices may be provided by a single strip of rubber or like material fixed to the tube at or about the upper region of the tube by any convenient securing means. For example, the strip may be fixed to the tube by an adhesive securing means. As another example, the strip may be fixed to the tube by pop rivets at spaced intervals. Alternatively a cover plate of V-section can be used to clamp the strip to the tube.

The discharge pot may be substantially conical or frusto-conical in shape.

Further features of, and certain advantages of, the present invention will be better understood from the following description of a particular and non-limiting example of the invention, given with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic illustration of one kind of vehicle, a trailer, embodying four discharge pot arrangements according to one example of the present invention; Figure 2 is a vertical axial cross-section through the lower part of one of the discharge pot arrangements illustrated in Fig. 1; Figure 3 is a view taken at right angles to Fig. 2; Figure 4 is a cross-section taken in a vertical plane and on a larger scale illustrating details of one example of cross-tube arrangement; and Figure 5 is a view similar to Fig. 4 but illustrating in particular the arrangement of a flap and a cover plate on the cross-tube.

In the drawings, like parts are represented by like reference numerals.

While a discharge pot arrangement on a vehicle is illustrated, it will be appreciated that a discharge pot of similar design can be used in manufacturing plants handling powdered or particulate material.

Referring firstly to Fig. 1, there is illustrated a trailer container vehicle 10 having a hollow body 12 for containing powdered or particulate material and provided with four discharge pot arrangements 14. The container can be discharged by pressure or by gravity. As illustrated, though this is not essential, the rearmost one of these discharge pot arrangements is located between the rear axles of the trailer wheel 16. A motorised tractor 18 of conventional design can be attached by a conventional pivot coupling or "fifth wheel" arrangement 20 to the trailer 10. Hatches 22 for filling or access are located along the top of the vehicle body 12.

Referring now to Fig. 2, the illustrated discharge pot arrangement has a downwardly tapering discharge pot defined by walls 24. An exit orifice 26 for material is located at the lower region of the walls 24. This leads into an outlet pipe 28 which includes a conventional butterfly valve 30. A tube 32 extends across the discharge pot, one end 34 of the tube being closed by the wall 24 and there being an air entry opening 36 at the other end. Connected to the air entry opening 36 is an air supply pipe 38 which incorporates a control valve 40 therein. The arrangement is such that all air supplied along pipe 38 passes into tube 32. The tube 32 has spaced air exit orifices 42, four being shown, but in practice there will normally be many more.The number, shape, size and spacing of the air exit orifices are chosen in accordance with the requirements for aeration of the powdered or particulate material that is to be carried. Each of these orifices 42 is associated with a cover flap, as will be better understood from Fig. 5 and its associated description.

In a practical example of the invention, the discharge pot arrangement will be constructed of aluminium or aluminium alloy, and the pipe 38 (Fig. 2) may be of a like material. It is welded by welds 39 to the wall 24, and a cross tube 32 may also be of welded aluminium or aluminium alloy. As seen in Figs. 2 and 3, the left hand end of the tube 32 is closed off by the wall 24 and the two ends of the tube are welded to the walls 24 as seen for example at 33.

Referring now to Fig. 4, a preferred embodiment of cross tube 32 is formed of a sheet 48 of aluminium bent as indicated and welded at 49 to a substantially planar strip 50. The cross tube is supported by a plate 52, although this is not essential. As seen, the longitudinal edges 54 of the plate 52 project outwardly some distance beyond the confines of the tube 32.

Referring now to Fig. 5, this is similar to Fig. 4 except as regards the location of the air exit orifices 42 and except that Fig. 5 illustrates an integral rubber flap 56 and a cover plate 58. The rubber flap 56 extends over substantially the whole length of the cross tube 32, and a cover plate 58 in shape approximating to an inverted V overlies the flap 56. These two parts are secured to the wall of the cross tube 32 by any convenient means, for example by a pop rivet one of which is illustrated at 60 in Fig. 5. As will be seen, a marginal portion 54 of the plate 52 on each side of the cross tube 32 extends beyond the confines of the cross tube 32, and upon each of these lips 54 rests the respective free edges of the flap 56. As seen; the cover plate 58 is bent slightly away from the tube 32, the bent-away portion being illustrated at 62.The purpose of this is to provide some clearance for passage of air which is forced out under pressure through the air exit orifices 32, lifts the flap 56 and passes between the flap 56 and the wall of the tube 32 and out into the container to fluidise the particulate contents of the container.

In a preferred version of the invention, the air exit orifices 42 are circular holes of approximately one half inch diameter, spaced at 12 inch centres (that is, holes approximately 12 millimetre diameter spaced at approximately 38 millimetre centres).

It will be understood that the present invention is not limited by the dimensions and particular materials mentioned in this specific description. By way of example, the outlet pipe may be a pipe of diameter substantially 5 inches (125 millimetres) and the cross tube 32 may have a substantially triangular cross section taken in a vertical plane, each side of the triangle being approximately 22 inches (63 millimetres) in length. The preferred material for the flap 56 is food grade rubber. As illustrated in the drawings, the discharge pot is substantially conical in shape, but the invention is equally applicable to a discharge pot of any other conventional shape.

Among the advantages of the invention as particularly disclosed and illustrated herein are the following: 1. The discharge pot arrangement can easily be washed out, because there is no fibrous or porous aeration pad, as is common in conventional designs, these pads giving rise to difficulties when wetted. To overcome these problems, it has become customary to have a hinged hatch at the base of a discharge pot arrangement, kept closed by a peripheral array of clips, clamps, or screw threaded "tee cou plings". Moreover, as the air under pressure used for aerating and fluidising the contents is fed in at the base of conventional discharge pots, before one can open the hinged panel at the base of the conventional discharge pot, one has to disconnect the air supply pipe.As a consequence of this, it is necessary to provide a coupling or pipe joint in that area on the air supply pipe which leads to further costs and manufacturing complexity.

2. A cross tube arrangement for providing aerating air offers a small obstruction to any exiting product, and its sloping configuration with vertex upwards allows particular and powdered materials to flow past easily. The arrangement of cover plate 58 and flap 56 prevents any exiting powdered or particular material from passing into the interior of the cross tube 32.

3. Because no hinged flap and associated clips or couplings are needed, these parts conventionally being made as aluminium castings, the resulting discharge pot arrangement as disclosed herein is lighter, more easily manufactured, and less expensive.

4. Because of the simplicity and lightness, it may be easily and inexpensively fitted to existing vehicles.

5. Because the powdered material outlet is located directly at the base of the tapering discharge pot arrangement, outflow of the material is more satisfactory than in conventional arrangements where a hinged flap is arranged to be downwardly sloping to an orifice arranged substantially in a vertical plane at the lower end of the hinged flap. This arrangement, which is conventional, causes the exiting material to have to make a sharp right angle bend immediately adjacent to the aeration pad located in the hinged flap, leading to a less efficient flow path.

Claims

1. A discharge pot arrangement for powdered or particulate material which can be discharged by gravity or air-entrainment, the arrangement comprising a downwardly-tapering discharge pot having an exit orifice for the material at or near its lower end, at least one tube extending across the discharge pot, and there being an air entry opening at the other end, the tube having a plurality of air exit orifices at spaced intervals therealong, these orifices being associated with one or more cover flaps, the flaps being arranged so that absent any air flow from the orifices they close the orifices under the influence of gravity and are forced away from the orifices when air under pressure is supplied to the interior of the tube.

2. An arrangement according to claim 1 in which the tube has a cross-sectional shape such that passage past it of descending powdered or particulate material is facilitated.

3. An arrangement according to claim 1 or 2 in which the flap or flaps are of natural or synthetic rubber or a flexible and waterproof synthetic plastics material.

4. An arrangement according to claim 1, 2 or 3 in which the flaps over the orifices are provided by a single strip of rubber or like material fixed to the tube or at about the upper region of the tube by any convenient securing means.

5. An arrangement according to any of claims 1-4 in which the strip is fixed to the tube by an adhesive securing means.

6. An arrangement according to any one of claims 1-4 in which the strip is fixed to the tube by pop rivets at spaced intervals.

7. An arrangement according to any of claims 1-4 in which a cover plate of V-section is used to clamp the strip to the tube.

8. An arrangement according to any preceding claim in which the discharge pot is substantially conical or frusto-conical in shape.

9. A discharge pot arrangement according to any preceding claim when mounted on a vehicle.

10. A discharge pot arrangement substantially as herein described with reference to and as illustrated in the accompanying drawings.

11. A vehicle substantially as herein described with reference to and as illustrated in the accompanying drawings.

12. Any novel combination or sub-combination disclosed and/or illustrated herein.