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(11) | EP 0 060 658 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Containers for bulk materials |
| (57) A bin 10 which contains bulk material in use has mounted at its lower end a discharger
body 11 whereby the material may be discharged from the container through an outlet
cone 12. The discharger is mounted on the bin 10 by means of an annular resilient
seal 17 which is axially interposed between respective flanges 20 and 22 on the bin
and the discharger respectively, the flange 22 being disposed above the flange 20
so that the downward loading of the material on the discharger is converted into a
compressive axial loading on the seal 17. The resilience of the seal enables the discharger
to be vibrated in the usual manner to ensure smooth flow of the material out of the
container. |
[0001] This invention relates to containers for the storage and/or transportation of granular or the like material in bulk.
[0002] Typically, a container of this type comprises a bin in which the material is contained in use, and a discharger mounted on the bin and providing an outlet therefrom, the discharger being vibrated relative to the bin to ensure smooth flow of the material through the outlet. In conventional constructions, the discharger is supported from the bin by means of so-called hangers, which are a series of tie rods arranged at invervals around the bin and incorporating anti-vibration mountings to permit the discharger bo move slightly relative to the bin as it is vibrated. With bins having a comparately large capcity, the head load exerted on the discharger is increased (sometimes to as much as 100 tonnes) and the hangers must be made more massive to accommodate the increased tensile loads to which they are subjected. The resultant construction tends to be complicated and therefore difficult to assemble.
[0003] Where the discharger incorporates, for example, a conical baffle disposed in the bin outlet, the pressure exerted by the material on the baffle tends to push the baffle and hence the discharger to one side, an effect which becomes cumulative. The pressures involved can be so great that the hangers are distorted, requiring the latter to be replaced after a certain amount of usage.
[0004] In order to prevent leakage of the material from between the bin and the discharger, a flexible seal is provided in the form of an annular band secured at one axial end thereof to a lower part of the bin and at the opposite axial end to an upper part of the discharger. The internal surface of the seal is exposed to the material as it flows from the bin to the discharger, and the abrasive effect of the material can damage the seal.
[0005] It will thus be appreciated that conventional containers are somewhat disadvantageous in the above- mentioned effects. It is an object of the present invention to obviate or mitigate these disadvantages.
[0006] According to the present invention, there is provided a container for storing and/or transporting granular or the like material in bulk, comprising a bin in which the material is contained in use, and a discharger providing an outlet from the bin and which is vibrated relative to the bin to ensure smooth flow of the material through the outlet, the discharger being mounted on the bin through the intermediary of an annular resilient seal which surrounds the outlet, the mounting being such that downward loading of the material on the discharger in use is converted to compressive axial loading on the seal.
[0007] Preferably, the bin and the discharger are each provided with a respective annular flange which surrounds the outlet, and the seal is axially interposed between the flanges with the flange on the discharger being disposed above the flange on the bin. Conveniently, one of the flanges (desirably, the flange on the discharger) includes an annular engagement portion which engages the seal and at least one mounting portion provided on a body of the discharger or the bin, as the case may be, the engagement portion being detachably secured to the or each mounting portion. The engagement portion is preferably split into a plurality of parts which can be separated to enable it to be assembled in position.
[0008] In addition to being interposed between axially facing surfaces of the bin and the discharger, the seal can also be engaged between inwardly and outwardly facing surfaces thereof.
[0009] The present invention will now be further described, by way of example, with reference to the accompanying drawings, in which:-
Figure 1 is a side view, partly in section, of a container according to the present invention;
Figure 2 is an enlargement of part of the container shown in Figure 1; and
Figure 3 is a similar view to Figure 2, but showing part of a modified container, also according to the present invention.
[0010] Referring first to Figure 1, the container shown therein comprises a silo or bin 10 (only the lower part of which is shown) in which bulk granular or the like material is contained in use for storage and/or transportation. A discharge outlet for the bin is provided by a discharger comprising a body 11 and a detachable outlet cone 12. A conical baffle 13 is mounted on the discharger body 11 and extends into an outlet opening 14 of the bin 10, so that material flowing out of the bin passes through an annular space 15 between the baffle 13 and the edge of the opening 14. Smooth flow of the material is promoted by a vibrator motor 16 which vibrates the assembly of the discharger body 11, outlet cone 12 and conical baffle 13 relative to the bin 10, such vibration being permitted by an annular resilient seal 17 by means of which the discharger is mounted on the bin.
[0011] Referring now also to Figure 2, the bin 10 has an annular, channel-section member 18 welded to its lower end and supported therefrom by means of gussets 19, the member 18 including an annular, outwardly-directed flange 20. On the other hand, the discharger body 11 has welded to its upper end an annular, angle-section member 21 to which is detachably secured an annular, inwardly- directed engagement plate 22. The seal 17 is axially interposed between the flange 20 and the plate 22 such that the downward force exerted on the discharger by the weight of the material in the bin is received by the seal 17 as a compressive loading. Thus, in addition to preventing the leakage of material from between the bin and the discharger, the seal 17 constitutes a flexible mounting whereby the discharger can be vibrated relative to the bin as described above, and in this respect replaces the hangers of a conventional container.
[0012] In addition to engaging the flange 20 and the plate 22 in the axial direction, the seal 17 also engages a radially outwardly facing surface 23 of the channel-section member 18 and a radially inwardly facing surface 24 of the angle-section member 21. The seal 17 also has an annular recess 25 in its lower surface in which the flange 20 is received, so that an outer peripheral edge 26 of the flange abuts the seal 17. Such engagement of the seal with the member 18 and themenber 21 in the radial direction resists sideways movement of the discharger due to the loading imposed on the conical baffle 13 by the weight of the material in the bin 10, and therefore there is little tendency for a cumulative offset of the discharger relative to the bin to occur due to such loading.
[0013] The seal 17 can be produced as a continuous annulus, or can be manufactured in strip form and turned into an annulus by joining together the ends of the strip, the ends preferably being mitred and bonded. The seal can be made of any suitable resilient material, such as rubber: however, it is desirable to use the material elastomer "SORBOTHANE" which is a polyurethane/marketed by Permali Gloucester Limited. This material has good sealing and pressure-absorbing properties, and also has the advantage that it can be poured in liquid form into a suitably shaped mould in order to produce the seal.
[0014] From the drawings, it will be appreciated that the only part of the seal 17 which is exposed to the interior of the container faces downwardly and is removed from the main flow path of the material through the discharger. Therefore, the seal is not prone to becoming damaged by the abrasive effect of. the material, in contrast to the seal employed in conventional containers.
[0015] The seal 17 is mounted on the channel-section member 18 simply by stretching it until sufficiently large in diameter to pass over the flange 20. The discharger is then mounted in position by engaging the plate 22 on the upper surface of the seal 17, and securing the plate 22 to the angle-section member 21 by means of bolts (not shown) which pass through bolt holes 27. In order to facilitate passage of the plate 22 over the flange 20, the former is radially split at two diametrically opposed points so that the resultant pair of parts thereof can be separated. It will be manifest from the above that the seal 17 is not secured to.either of the flange 20 and the plate 22, being merely held in place between the discharger and the bin. Therefore, assembly of the discharger on the bin is a simple operation, in contrast to conventional containers which employ a series of hangers for this purpose.
[0016] The construction shown in Figures 1 and 2 is applicable to containers of relatively large capacity, the discharger body 11 being in the form of a spun dish. Figure 3 illustrates a modified construction which is applicable to containers of smaller capacity, the discharger body 11 now being in the form of a fabricated cone. The angle-section member 21, the engagement plate 22 and the seal 17 are of generally the same form as in the construction of Figures 1 and 2. The channel-section member 18 is, however, omitted and the seal 17 instead engages an outwardly directed flange 28 on the bottom of the bin 10. It will be noted that the seal 17 is still engaged in the radial direction between an inwardly-facing surface of the member 21 and the outer periphery of the flange 28, so that cumulative offset of the discharger due to the weight of the material held in the bin 10 is once again resisted.
[0018]
(1) The discharger is easily mounted on the bin, it being necessary merely to jack the discharger in position, fit the seal, and bolt the engagement plate 22 to the discharger body.
(2) The sealing qualities are improved, since a heavy-duty seal is used in a position which is not vulnerable to abrasion by the material.
(3) Because there is no solid connection between the discharger and the bin, little vibration is transmitted to the latter.
(4) Cumulative offset of the discharger relative to the bin due to the pressureof the material is resisted.
(5) In very large containers where great head loads occur, it is possible to obtain a very favourable load distribution on the seal because, being of large diameter in this case, the load-receiving area of the seal is relatively great.
1. A container for storing and/or transporting granular or the like material in bulk,
comprising a bin (10) in which the material is contained in use, a discharger (11,
12) providing an outlet from the bin (10) and which is vibrated relative to the bin
to ensure smooth flow of the material through the outlet, means mounting the discharger
(11, 12) on the bin (10), and an annular resilient seal (17) provided between the
discharger (11, 12) and the bin (10) and surrounding the outlet, characterised in
that the annular resilient seal (17) constitutes said mounting means and is so arranged
that downward loading of the material on the discharger (11, 12) in use is converted
to compressive axial loading on the seal (17).
2. A container as claimed in Claim 1, wherein the bin (10) and the discharger (11,
12) are each provided with a respective annular flange (20,22) which surrounds the
outlet, and the seal (17) is axially interposed between the flanges with the flange
(22) on the discharger (11, 12) being disposed above the flange (20) on the bin (10).
3. A container as claimed in Claim 2, wherein one of the flanges (20, 22) includes
an annular engagement portion (22) which engages the seal (17) and at least one mounting
portion (21) provided on a body of the discharger (11, 12) or the bin (10), as the
case may be, the engagement portion (22) being detachably secured to the or each mounting
portion (21).
4. A container as claimed in Claim 3, wherein said one of the flanges is the flange
(22) on the discharger (11, 12).
5. A container as claimed in Claim 3 or 4, wherein the engagement portion (22) is
split into a plurality of parts which can be separated to enable it to be assembled
in position.
6. A container as claimed in any one of Claims 2 to 5, wherein the seal (17) engages
the periphery of the flange (28) on the-bin (10).
7. A container as claimed in any one of Claims 2 to 6, wherein the discharger (11,
12) is disposed radially outwardly of the bin (10) in the region of the discharge
outlet.
8. A container as claimed in any preceding claim, wherein the seal (17) is interposed
between respective axially facing surfaces on the bin (10) and the discharger (11,
12),and is also engaged between inwardly and outwardly facing surfaces (23, 24) thereof.
9. A container as claimed in any preceding claim, wherein the seal (17) is made of
a polyurethane elastomer.
10. A container as claimed in any preceding claim, wherein the discharger includes
an upwardly convex part (13) disposed in the discharge outlet.