AU2018222912A1 - Enhanced flow storage bin - Google Patents

Abstract

Abstract 5 A bulk storage bin 10 for handling particulate material 16 is described. The bin comprises an upper storage section 12 wherein a bulk of the particulate material 16 is held. The bulk storage bin 10 also comprises a lower discharge section 14 which is independent of the upper storage section 12 and separated from the upper storage section 12 by a predefined spacing. In use, 10 as the particulate material 16 discharges from the bin 10 the spacing allows the material to rill freely from the upper storage section 12 into the lower discharge section of the bin 14. The free rilling of the particulate material 16 at this point substantially eliminates any constriction where the material is forced to change direction. In this way the possibility of 'dead' regions or 15 hang-ups of particulate material is substantially eliminated. Drawing to accompany Abstract: Figures 5 to 8 .-o (D CLC) .10~ -K-' I c4 - - - - - - - -

Description

Applicant:

Lycopodium Minerals Pty Ltd

Associated Provisional Application No.: 2017904451

The following statement is a full description of the invention, including the best method of performing it known to me:

2018222912 28 Aug 2018 “ENHANCED FLOW STORAGE BIN”

Field of the Invention

The present invention relates to a bulk storage bin or hopper for particulate 5 material with enhanced flow characteristics and relates particularly, though not exclusively, to such a bulk storage bin used in the mining industry for handling ore.

Background to the Invention

The purpose of a bulk storage bin or hopper is not only to store the particulate material, but also to allow it to be recovered in a controlled manner and fed it into a downstream process. Bulk storage bins are used in the mining industry, for example, when loading ore onto transport means such as a conveyor belt or rail cars. When particulate material flows out of a bin or hopper under gravity alone, typically two extremes of flow pattern exist: mass flow and funnel flow. In mass flow the ore is discharged on a first-infirst out basis. To achieve mass flow the walls of the bin or hopper must be sufficiently steep and smooth to enable flow of all the solids in the bin without any ‘dead’ regions. In funnel flow, the ore is discharged on a last-in-first-out 20 basis. The particulate material flows towards the outlet through a vertical channel or funnel surrounded by stagnant material. Funnel flow patterns can lead to material build-up, blockages and unstable flow patterns with serious structural implications. Funnel flow patterns can also cause material to reside in the bin for far longer than planned with potentially significant 25 consequences - cementing, generation of acids, spoiling (foodstuffs), etc.

The present invention was developed with a view to providing a bulk storage bin with enhanced flow characteristics wherein the possibility of ‘dead’ regions or hang-ups of particulate material is substantially eliminated. Although the invention will be described with particular reference to 30 applications in the mining industry it will be appreciated that the storage bin has much wider application, also in other industries.

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References to prior art in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.

Summary of the Invention

According to one aspect of the present invention there is provided a bulk storage bin for handling particulate material, the bin comprising:

an upper storage section wherein a bulk of the particulate material is held; 10 and, a lower discharge section which is independent of the upper storage section and separated from the upper storage section by a predefined spacing wherein, in use, as the particulate material discharges from the bin the spacing allows the material to rill freely from the upper storage section into 15 the lower discharge section of the bin.

Advantageously the orientation of the lower discharge section relative to the upper storage section is adjustable, thus allowing the bin to be located in any configuration, with no resulting loss of flow performance. Preferably an angle of orientation Θ, of the lower discharge section relative to the upper storage 20 section, can vary from 0° to 360°, so that hang-ups can be eliminated to the greatest extent possible and flow and wear problems are predictable.

Preferably the lower discharge section has an elongated rectangular outlet. Advantageously the rectangular outlet is tapered to promote mass flow from the bin and avoid funnel flow. Preferably the rectangular outlet is tapered in 25 both a horizontal direction and a vertical direction. Typically the rectangular outlet is oriented so that the direction of travel of a feeder located below the outlet is from a narrower end to a wider end of the outlet.

In a preferred embodiment the lower discharge section is in the form of a rectangular prismatic hopper. Preferably the walls of the lower discharge

2018222912 28 Aug 2018 section are angled sufficiently steeply to enable mass flow of all the particulate material in the lower section without any ‘dead’ regions.

Preferably the upper storage section of the bin is cylindrical in shape.

Throughout the specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word “preferably” or variations such as “preferred”, will be understood to imply that a stated integer or group of integers is desirable but not essential to the 10 working of the invention.

Brief Description of the Drawings

The nature of the invention will be better understood from the following detailed description of several specific embodiments of the bulk storage bin, 15 given by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a side elevation and top plan view of a conventional circular bin with round to tapered outlet;

Figure 2 is a side elevation and top plan view of a conventional circular 20 bin with circular outlet;

Figure 3 is a side elevation and top plan view of a conventional square bin with square outlet;

Figure 4 is a side elevation and top plan view of a conventional square bin with rectangular outlet;

Figure 5 is a side elevation and top plan view of a first embodiment of the invention in the form of a circular bin with tapered rectangular outlet;

Figure 6 is a side elevation and top plan view of a second embodiment of the invention in the form of a square bin with tapered rectangular outlet;

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Figure 7 is a side elevation and top plan view of a third embodiment of the invention in the form of a circular bin with conical outlet to rectangular tapered hopper;

Figure 8 is a side elevation and top plan view of a fourth embodiment of the invention in the form of a square bin with tapered square outlet to rectangular tapered hopper; and,

Figure 9 is a top perspective view of a fifth embodiment of the invention in the form of a conveyor to conveyor chute transfer.

Detailed Description of Preferred Embodiments

A first embodiment of a bulk storage bin 10 for handling particulate material in accordance with the invention, as illustrated in Figure 5, comprises an upper storage section 12 wherein a bulk of the particulate material is held. In 15 this embodiment, the upper storage section is in the form of a bin 12 of circular cross-section, similar to a conventional circular bin as shown in Figure 1, but without the tapered conical outlet connected to its bottom end.

The bulk storage bin 10 further comprises a lower discharge section 14 which is independent of the upper storage section 12 and separated from the upper 20 storage section by a predefined spacing. As shown in Figure 5, the lower end of the circular bin 12 is located below an upper rim of the lower discharge section, which in this embodiment is in the form of a rectangular prismatic hopper 14. However there is sufficient spacing between the lower end of the circular bin 12 and the tapered walls of the rectangular hopper 14 so that, in 25 use, as the particulate material 16 discharges from the bin the spacing allows the material to rill freely from the upper storage section 12 into the lower discharge section 14 of the bin. The free rilling of the particulate material 16 at this point substantially eliminates any constriction where the material is forced to change direction.

In a conventional bin, such as that shown in Figures 1 to 4, there is a point where the ore is ‘compressed' and forced to change direction and flow to the

2018222912 28 Aug 2018 outlet. This is referred to as the ‘switch point’ and results in compression of the ore at this point that may result in hang-ups. However in the storage bin 10 of the present invention, the free discharge from the storage bin promotes flow and the resulting pressure distribution in the bin is greatly simplified as 5 the switch point has been eliminated. Rather, the upper section 12 of the bin, being independent of the lower section 14, allows the flow to expand at what is normally the switch point, eliminating the switch point pressure completely.

The resulting pressure distribution in the upper section 12 of the bin, now that the switch point has been eliminated, is simply lateral pressure and wall 10 friction which is fully understood and easily designed for. The resulting pressure distribution in the lower section 14 of the bin, now that the switch point has been eliminated, is both lateral pressure, wall friction and vertical pressure, which is also fully understood and easily designed for.

In addition to the significantly enhanced flow and favourable pressure 15 distribution, a number of other significant design benefits result:

Upper Storage Section design

This section can be either cylindrical or rectangular (including sguare) in shape - either shape can be flanged for ease of erection and transport - as the upper storage section 12 is independent of the lower discharge section 20 14. With conventional designs, a cylindrical upper storage section is not ideal as there is a difficult and expensive transition from the circular section to a rectangular outlet in the lower discharge section (as in the case of a conveyor feed to a train loading bin).

A cylindrical upper storage section 12 in particular, such as that shown in 25 Figure 5, offers further advantages in that it results in the least cost as the circular section is best able to withstand the resulting stresses.

Lower Discharge Section design

The lower discharge section 14 can be either conical in shape with circular outlet or prismatic with rectangular outlet.

2018222912 28 Aug 2018

As the lower section 14 is independent of the upper section 12: (i) The orientation of the lower section 14 relative to the upper section 12 is fully adjustable, thus allowing the bin to be located in any configuration, with no resulting loss of flow performance, i.e. angle Θ in Figures 5 to 8 can vary from 5 0° to 360°. Hang-ups can therefore be eliminated to the greatest extent possible and flow and wear problems are readily predictable, (ii) The setup of the lower section 14 is fully and readily adjustable. This is critical in those applications such as train loading, where the position and level of the lower storage section flanged outlet is critical to performance in terms of rail-car 10 filling efficiency and prevention of spillage.

Preferably the lower discharge section 14 has an elongate rectangular outlet

18. The lower section 14 of the bin usually feeds onto a feeder of some description - typically an apron feeder, a belt feeder or a vibrating feeder (not shown). Advantageously the long rectangular outlet 18 in the prismatic lower 15 section 14 is tapered to promote mass flow from the bin and avoid funnel flow. Preferably the rectangular outlet 18 is tapered in both a horizontal direction, as can be seen in the top plan view of Figure 5, and in a vertical direction, as can be seen in the side elevation of Figure 5. Typically the feeder travel is in the direction from the narrower end to the wider end of the 20 outlet 18. This does not preclude the use of a lower discharge section designed with a square or circular outlet.

A second embodiment of a bulk storage bin 20 for handling particulate material in accordance with the invention, as illustrated in Figure 6, comprises an upper storage section 22 wherein a bulk of the particulate 25 material is held. In this embodiment, the upper storage section is in the form of a bin 22 of square cross-section, similar to a conventional square bin as shown in Figure 3, but without the tapered square outlet connected to its bottom end.

The bulk storage bin 20 further comprises a lower discharge section 14 which 30 is independent of the upper storage section 22 and separated from the upper storage section by a predefined spacing. As shown in Figure 6, the lower end

2018222912 28 Aug 2018 of the square bin 22 is located below an upper rim of the lower discharge section, which in this embodiment is similar to the first embodiment of Figure 5, and is in the form of a rectangular prismatic hopper 14. As with the previous embodiment, there is sufficient spacing between the lower end of 5 the square bin 22 and the tapered walls of the rectangular hopper 14 so that, in use, as the particulate material discharges from the bin the spacing allows the material to rill freely from the upper storage section 22 into the lower discharge section 14 of the bin. The free rilling of the particulate material at this point substantially eliminates any constriction where the material is 10 forced to change direction.

In other respects the bulk storage bin 20 of this embodiment is substantially identical to the first embodiment of the bulk storage bin 10 and will not be described again in detail.

A third embodiment of a bulk storage bin 30 for handling particulate material 15 in accordance with the invention, as illustrated in Figure 7, comprises an upper storage section 32 wherein a bulk of the particulate material is held. In this embodiment, the upper storage section is in the form of a circular bin 32, similar to a conventional circular bin as shown in Figure 2, with a conical circular outlet 36 connected to its bottom end. While in this case the conical 20 circular outlet is located below the switch point (and thus the switch point pressure exists), the circular section is more readily capable of accommodating the resulting stress and any alignment issues can be accommodated by varying angle Θ.

The bulk storage bin 30 further comprises a lower discharge section 34 which 25 is independent of the upper storage section 32 and separated from the upper storage section by a predefined spacing. As shown in Figure 7, the lower end of the circular bin 32 is located below an upper rim of the lower discharge section, which in this embodiment is in the form of a rectangular tapered hopper 34. However there is sufficient spacing between the lower end of the 30 circular outlet 36 and the tapered walls of the rectangular hopper 34 so that, in use, as the particulate material discharges from the bin the spacing allows

2018222912 28 Aug 2018 the material to rill freely from the upper storage section 32 into the lower discharge section 34 of the bin.

As with the previous embodiments, the lower discharge section 34 preferably has an elongate rectangular outlet 38. The long rectangular outlet 38 in the rectangular hopper 34 is preferably tapered to promote mass flow from the bin and avoid funnel flow. In other respects the bulk storage bin 30 of this embodiment is similar to the first embodiment of the bulk storage bin 10 and will not be described again in detail.

A fourth embodiment of a bulk storage bin 40 for handling particulate material 10 in accordance with the invention, as illustrated in Figure 8, comprises an upper storage section 42 wherein a bulk of the particulate material is held. In this embodiment, the upper storage section is in the form of a square bin 42, similar to a conventional square bin as shown in Figure 3, with a square outlet 46 connected to its bottom end. As with the previous embodiment, the 15 square outlet is located below the ‘switch point’ (and thus the switch point pressure exists), any alignment issues can be accommodated by varying angle Θ.

The bulk storage bin 40 further comprises a lower discharge section 34 which is independent of the upper storage section 42 and separated from the upper 20 storage section by a predefined spacing. As shown in Figure 8, the lower end of square outlet 46 is located below an upper rim of the lower discharge section, which in this embodiment is similar to the third embodiment of Figure 7, and is in the form of a rectangular tapered hopper 34. However there is sufficient spacing between the lower end of the square outlet 46 and the 25 tapered walls of the rectangular hopper 34 so that, in use, as the particulate material discharges from the bin the spacing allows the material to rill freely from the upper storage section 42 into the lower discharge section 34 of the bin.

In other respects the bulk storage bin 40 of this embodiment is similar to the 30 first embodiment of the bulk storage bin 10 and will not be described again in detail.

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A fifth embodiment of a bulk storage bin 50 for handling particulate material in accordance with the invention, as illustrated in Figure 9, comprises an upper storage section 52 wherein a bulk of the particulate material is held. Figure 9 also shows the prior art discharge chute 66. In this embodiment, the 5 upper storage section is in the form of an upper chute 52 that receives particulate material from a first conveyor (not shown) and discharges it onto a second downstream conveyor 56.

The bulk storage bin 50 further comprises a lower discharge section 54 which is independent of the upper chute 52 and separated from the upper chute by 10 a predefined spacing. As shown in Figure 9, the lower end of the upper chute is located below an upper rim of the lower discharge section 54, which in this embodiment is in the form of a rectangular tapered hopper 54 that connects to a lower portion of the discharge chute that discharges onto conveyor 56. However there is sufficient spacing between the lower end of 15 the upper chute 52 and the tapered walls of the rectangular hopper 54 so that, in use, as the particulate material discharges from the bin the spacing allows the material to rill freely from the upper chute 52 into the lower discharge section 54. The material flows onto the downstream conveyor 56 in an efficient and controlled manner so as to evenly load the downstream 20 conveyor, eliminating any potential tracking issues from developing and spillage.

It will be seen from this embodiment how the same principle of the present invention can be used to effect a difficult conveyor to conveyor discharge, where the transfer angle is such that a complex geometry in the discharge 25 chute design results. As can be seen in the prior art discharge chute 66, shown in Figure 9, the geometry of the discharge chute is quite complex and therefore prone to additional dead spots and hang-ups.

In each of the above embodiments the spacing of the upper storage section of the bin from the lower discharge section may vary significantly from what is 30 shown in the drawings. The spacing is set according to the natural rill of the particulate material and so as to avoid spillage.

2018222912 28 Aug 2018

In each of the illustrated embodiments the walls of the lower discharge section are angled sufficiently steeply to enable mass flow of all the particulate material in the lower section without any ‘dead’ regions.

Now that preferred embodiments of the bulk storage bin have been described 5 in detail, it will be apparent that the described embodiments provide a number of advantages over the prior art, including the following:

(i) Because the upper section of the bin is independent of the lower section the flow can be allowed to expand at what is normally the switch point, and in this way the switch point pressure eliminated.

(ii) The resulting pressure distribution in the upper section of the bin is simply lateral pressure and wall friction which is fully understood and easily designed for.

(iii) Likewise, the resulting pressure distribution in the lower section of the bin is both lateral pressure, wall friction and vertical pressure, which is also fully understood and easily designed for.

(iv) The orientation of the lower section relative to the upper section is fully adjustable, thus allowing the bin to be located in any configuration, with no resulting loss of flow performance.

(v) Because the upper section of the bin is independent of the lower section the design of the upper section may be significantly simplified.

It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing 25 embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention. For example, although in each of the illustrated embodiments the lower discharge section of the storage bin is of rectangular configuration, this is by no means essential to the invention. The lower discharge section may also be of circular

2018222912 28 Aug 2018 configuration. Therefore, it will be appreciated that the scope of the invention is not limited to the specific embodiments described.

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The Claims defining the invention are as follows:

Claims (10)

1. A bulk storage bin for handling particulate material, the bin comprising:

5 an upper storage section wherein a bulk of the particulate material is held; and, a lower discharge section which is independent of the upper storage section and separated from the upper storage section by a predefined spacing wherein, in use, as the particulate material discharges from the bin the 10 spacing allows the material to rill freely from the upper storage section into the lower discharge section of the bin.

2. A bulk storage bin as defined in claim 1, wherein the orientation of the lower discharge section relative to the upper storage section is adjustable, thus allowing the bin to be located in any configuration, with no resulting loss

15 of flow performance.

3. A bulk storage bin as defined in claim 2, wherein an angle of orientation Θ, of the lower discharge section relative to the upper storage section, can vary from 0° to 360°, so that hang-ups can be eliminated to the greatest extent possible and flow and wear problems are predictable.

20

4. A bulk storage bin as defined in any one of claims 1 to 3, wherein the lower discharge section has an elongated rectangular outlet.

5. A bulk storage bin as defined in claim 4, wherein the rectangular outlet is tapered to promote mass flow from the bin and avoid funnel flow.

6. A bulk storage bin as defined in claim 5, wherein the rectangular outlet is 25 tapered in both a horizontal direction and a vertical direction.

7. A bulk storage bin as defined in claim 6, wherein the rectangular outlet is oriented so that the direction of travel of a feeder located below the outlet is from a narrower end to a wider end of the outlet.

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8. A bulk storage bin as defined in any one of the preceding claims, wherein the lower discharge section is in the form of a rectangular prismatic hopper.

9. A bulk storage bin as defined in claim 8, wherein the walls of the lower discharge section are angled sufficiently steeply to enable mass flow of all

5 the particulate material in the lower section without any ‘dead’ regions.

10. A bulk storage bin as defined in claim 9, wherein the upper storage section of the bin is cylindrical in shape.