AU2016100776A4

AU2016100776A4 - Coal saver

Info

Publication number: AU2016100776A4
Application number: AU2016100776A
Authority: AU
Inventors: Steven CHANDLER; Matthew Maohu Wang
Original assignee: YANCOAL AUSTRALIA Ltd
Current assignee: YANCOAL AUSTRALIA Ltd
Priority date: 2011-05-31
Filing date: 2016-05-27
Publication date: 2016-06-23
Anticipated expiration: 2020-01-31
Also published as: AU2016100776B4

Abstract

H:\cab\Intrwovn\NRPortbl\DCC\CAB\5814964_I.doc-13/11/2013 A coal caving system including a canopy for supporting a mine roof and a conveyor positioned beneath the canopy which also includes a rear canopy with a slider door for selectively caving coal onto the conveyor, the system further including a coal saver device coupled relative to the conveyor for at least partially filling a goaf region adjacent the conveyor, wherein the device includes a tray arranged to be supported directly on a ground surface to accumulate coal which forms into a mound in the goaf region and serves to direct goaf spill onto the conveyor.

Description

COAL SAVER

RELATED APPLICATION

[0001] This application is entitled to priority from Australian Patent Application No. 2011902122, the contents of which are incorporated by reference.

[0001A] This application claims divisional status from Australian Patent Application No. AU2012262642, the contents of which are incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a coal saving device particularly but not exclusively for use in a longwall top coal caving (LTCC) system.

BACKGROUND OF THE INVENTION

[0003] A longwall top coal caving (LTCC) system 1, as shown in profile in Figure 1, is used in coal mining for the extraction of coal from a long, generally thick coal seam.

[0004] The system 1 includes a canopy 2 supported by a pontoon 3 on hydraulic legs 4. The canopy 2 is for supporting a roof of the mine above the system 1. A flipper 8 extends from the canopy 2 against a face 9 of the mine. The canopy 2 and flipper 8 provide protection for a front conveyor 10, which transports coal along the face, as it is cut from the face.

[0005] In the position shown, the conveyor 10 has been moved forward relative to the pontoon 3, ready for a new cutting cycle at the face 9.

[0006] The system 1 also includes a rear canopy 11, which is used to cave and protect rear conveyor 15 on a goaf side 12. The goaf 13 is the cavity behind the longwall. The rear canopy 11 also includes a slide door 14 which is extended to stop the flow of coal caving onto the conveyor 15.

[0007] After the caving process is finished, the rear conveyor 15 is moved in order to allow the overall system 1 to continue walking in a direction from right to left, as viewed, during each cutting cycle. For that purpose, a piston 16 and chain 17 are used to retract the rear conveyor 15 to a position adjacent the pontoon 3, as shown in Figure 2.

[0008] As soon as the rear conveyor is pulled forward, the goaf 13 will be filled by coal spilled from the rear conveyor 15 and also coal from the next cycle shield advance.

OBJECT OF THE INVENTION

[0009] The present invention seeks to provide a device to help save coal left in the goaf. SUMMARY OF THE INVENTION

[0010] In accordance with the invention, there is provided a coal caving system including a canopy for supporting a mine roof and a conveyor positioned beneath the canopy which also includes a rear canopy with a slider door for selectively caving coal onto the conveyor, the system further including a coal saver device coupled relative to the conveyor for at least partially filling a goaf region adjacent the conveyor, wherein the device includes a tray arranged to be supported directly on a ground surface to accumulate coal which forms into a mound in the goaf region and serves to direct goaf spill onto the conveyor.

[0011] Preferably, the device includes an upturned lip along an outer edge of the tray.

[0012] Preferably, the device is coupled to a panline supporting the conveyor by connectors which are designed to fail when subjected to an abovethreshold force so as to separate the device from the panline in the event the device becomes caught in the goaf.

[0013] Preferably, the tray is substantially flat and at a ground surface level so that the mound is built from substantially the ground surface level up.

[0014] Preferably, the system includes a plurality of canopies arranged along a coal face with corresponding rear canopies and an associated device arranged beneath each rear canopy.

[0015] In accordance with the invention, there is provided a coal saving device including a scoop arranged to sit adjacent a rear conveyor of an coal caving system, the scoop serving to accumulate coal which forms into a mound, thereby at least partially filling a goaf region behind the coal caving system, to direct further goaf spill onto the rear conveyor.

[0016] Preferably, the scoop includes a deck plate with an upturned lip along an outer edge.

[0017] Preferably, the scoop includes reinforced attachment plates toward an opposite edge, for connecting the scoop to a rear panline of an LTCC system.

[0018] In another aspect, there is provided a coal saving device including a tray and an upturned lip along an outer edge of the tray, wherein the tray is substantially flat so as to be supported at a ground surface level by way of an underside of the tray resting directly on the ground surface.

[0019] Preferably, the lip is angled at between 60° and 70° relative to the tray, to a height of between 100 mm and 300 mm.

[0020] Preferably, attachment points are provided along an opposite edge of the tray for carrying connectors adapted to fail in an abovethreshold condition to separate the device from a coal conveyor.

[0021] Preferably, the tray has a length in the order of 1650 mm and a width in the order of 700 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The invention is described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [0023] Figure 1 is an end view of an LTCC system; [0024] Figure 2 is an end view similar to that of Figure 1, showing a rear conveyor in a retracted position; [0025] Figure 3 is an end view similar to Figure 2, showing a coal saving device; [0026] Figure 4 is a perspective view of the device, showing attached to a panline of the LTCC; and [0027] Figure 5 is an end view of the device and panline of Figure 4.

DETAILED DESCRIPTION

[0028] Referring to Figure 3, the same longwall top coal caving (LTCC) system 1, as described with reference to Figures 1 and 2, is shown and like reference numerals are used to denote like parts.

[0029] A coal saving device 20 is also shown connected to a panline 21, which supports the rear conveyor 15. The device 20 is illustrated as comprising a scoop 22 formed by a tray/deck plate 23 with an upturned lip 24 along an outer edge 25. The tray 23 is substantially flat and positioned at a ground surface level whereby an underside of the tray 23 rests directly on top of and is supported by the ground surface over a substantial majority of the underside of the tray 23.

[0030] The scoop 20 serves to gather coal into a mound 26, to partially fill the goaf 13, up to and preferably above the level of the conveyor 15 so that any excess goaf spill is diverted from the mound 26 and directly on to the rear conveyor 15. Since the tray is at a ground surface level the mound 26 needs to be built from substantially the ground surface up. However, this is readily achieved as the coal in the goaf provides a ready source of material for that purpose.

[0031] Referring now to Figures 4 and 5, the scoop 22 is shown in more detail as including reinforced plates 27 adjacent an upturned inner edge 28. The plates 27 provide attachment points to connect the device 20 relative to the conveyor 15 via connectors/hinge pins 29 and a pair of clevis which are in turn welded to a frame 31 of the panline 21.

[0032] In one particular example, the length 'L' of the scoop 22 is in the order of 1650mm to 1750 mm although the saver may be up to 1960 mm in length. An example width 'W' is 700 mm. The angle of the outer edge 25 relative to the deck plate 23 may, for example, be either 60 degrees or 75 degrees to horizontal, as appropriate. The outer edge 25 may project upwardly by a height determined for the required conditions such as, for example, 100 mm, 200 mm or 300 mm.

[0033] The system 1 generally includes a multitude of canopies arranged along a length of a coal face with a corresponding plurality of rear canopies 11 and devices 20 arranged beneath each rear canopy 11. For example, ten or more such scoops are arranged along the length of the panline 21.

[0034] The connection between the panline 21 and device 20, via the connectors/hinge pins 29 and clevis 30, is rated to fail when the inertia of the coal heaped on top of the device 20 exceeds a threshold level for the piston 16. As such, if the device 20 becomes caught in the goaf 13, the hinge pins or clevis will shear under application of an abovethreshold force to separate the device 20 from the panline 21, in order that the associated canopy 2 can continue to advance without interrupting or compromising normal operation of the system 1.

[0035] An advantage of the device 20 is that the tray 23 can be formed of comparatively thin steel as it rests directly on a ground surface and does not need any reinforcement to support the weight load of the coal. As such, the device 20 can be manufactured for a relatively low cost.

[0036] Another advantage of the device 20 is that it uses coal from the goaf spill itself to form a mound on top of the scoop 22 to at least partially fill the goaf 13 and divert additional goaf spill up toward the panline 21. Accordingly, the device 20 provides the goaf filling function with waste material being coal, which further enhances the cost effectiveness of the device 20.

[0037] The device 20 is intended to be left in the mine, buried in the goaf spill after a mining operation. However, since the scoop 22 is relatively light and cheap to manufacture, the device 20 represents only a minimal capital investment to leave behind in the mine, compared to the additional revenue generated as a result of re-claimed coal from the goaf.

[0038] It is expected the device 20 will save an additional 3% of claimable coal from the mine and 20 this represents a significant financial benefit, even when the cost of leaving the device behind in the mine is factored in.

[0039] The coal saving device 20 has been described by way of non-limiting example only and many modifications and variations may be made thereto without departing from the spirit and scope of the invention described.

[0040] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0041] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

LIST OF PARTS 1. LTCC system 2. Canopy 3. Pontoon 4. Hydraulic legs 7. Roof 8. Flipper 9. Face 10. Front conveyor 11. Rear canopy 12. Goaf side 13. Goaf 14. Slide Door 15. Rear conveyor 16. Piston 17. Chain 20. Coal saving device 21. Panline 22. Scoop 23. Tray deck plate 24. Lip 25. Outer edge 26. Mound 27. Reinforced plates 28. Inner edge 29. Connectors/hinge pins 30. Clevis 31. Frame

Claims

CLAIMS:

1. A coal caving system including a canopy for supporting a mine roof and a conveyor positioned beneath the canopy which also includes a rear canopy with a slider door for selectively caving coal onto the conveyor, the system further including a coal saver device coupled relative to the conveyor for at least partially filling a goaf region adjacent the conveyor, wherein the device includes a tray arranged to be supported directly on a ground surface to accumulate coal which forms into a mound in the goaf region and serves to direct goaf spill onto the conveyor.
2. The system of claim 1, wherein the device includes an upturned lip along an outer edge of the tray.
3. The system of claim 2, wherein the device is coupled to a panline supporting the conveyor by connectors which are designed to fail when subjected to an abovethreshold force so as to separate the device from the panline in the event the device becomes caught in the goaf.
4. The system of claim 1, wherein the tray is substantially flat and at a ground surface level so that the mound is built from substantially the ground surface level up.
5. A coal saving device including a scoop arrangement for positioning adjacent a rear conveyor of a coal caving system, the scoop serving to accumulate coal which forms into a mound, thereby at least partially filling a goaf region behind the system, to direct further goaf spill onto the rear conveyor, wherein the scoop includes a deck plate with an upturned lip along an outer edge and wherein attachment points are provided along an opposite edge of the tray for carrying connectors adapted to fail in an abovethreshold condition to separate the device from a coal conveyor.