AU2013202336A1

AU2013202336A1 - Bulk Grout System

Info

Publication number: AU2013202336A1
Application number: AU2013202336A
Authority: AU
Original assignee: Alminco Pty Ltd
Current assignee: Alminco Pty Ltd
Priority date: 2012-06-26
Filing date: 2013-04-03
Publication date: 2014-01-16

Abstract

A bulk grout system comprising a hopper pod and a mixer pod, having interlocking formations to allow the two pods to be releasably interconnected for transport as a single unit. There is a closed compartment inside the hopper pod that is filled with powder before transport to the work area; and, the mixer pod carries two air operated mixers and two air operated pumps, one for each respective mixer. The pump units, can either be used simultaneously for continuous grout mixing and pumping, or, one mixer can be used for mixing while the mixed contents of the other is being pumped.

Description

AUSTRALIA Patents Act 1990 Alminco Pty Ltd COMPLETE SPECIFICATION Invention Title: Bulk Grout System The invention is described in the following statement: 2 Title Bulk Grout System Technical Field 5 This patent application concerns strata support for underground mining, in particular secondary support. In general, cable bolts are installed as secondary support when the primary support is not adequate to support an excavation. A cable bolt is inserted into a drilled hole and the cable bolt is grouted after initial installation.. In particular, the 10 grout may be pumped into the tail of the cable bolt, through a channel along the length of the bolt, and out of the end of the bolt into the space between the bolt and the walls of the hole in which it resides. As the grout solidifies the bolts are secured in the roof of the excavation, where they are used to stabilize it. 15 Background Art Conventional grouting procedures are generally as follows: a) Delivery of pallets pre-loaded with 20 kg bags of grout powder to the mine-site; b) Transport of the pallet(s) to an underground location using a Load Haul Dump 20 (LHD) vehicle; c) Individually breaking open each powder bag and manually pouring the dry grout powder into a mixer; d) Adding water to the mixer until the desired powder/water ratio is achieved; e) Mixing the powder and water until the desired viscosity is observably achieved; 25 f) Pumping the mixed grout into the bolts. Summary A first aspect of the bulk grout system comprises a hopper pod and a mixer pod, having 30 interlocking formations to allow the two pods to be releasably interconnected for transport to the work area, and out again, as a single unit. A closed compartment inside the hopper pod is filled with powder before transport to the work area. The mixer pod carries two air operated mixers and two air operated pumps, one 35 for each respective mixer.

3 The two mixers include a system to monitor the amount of water entering the mixer and assist in achieving the desired powder-to-water ratio. In use an air operated transport is used to selectively transfer powder from the hopper to the mixers; 5 The system has been designed primarily so it can typically produce enough mixed grout to last an entire shift at an underground coal mine. After this shift is over, the empty hopper is transported back to the surface and either re-filled, or replaced with a pre filled hopper. This allows a reduction in the intensity and duration of manual labour 10 required to complete the operation; leading to reduced operation costs and increased mine-site productivity. The system facilitates storage, transport, handling, mixing, and pumping of strata support grout. It is preferred that the hopper pod cannot pick up any equipment except the mixer pod, 15 and the formations may include horns that have intentionally been made wider than normal to prevent interconnection with other equipment. An air operated conveyor may be connected between the hopper pod and the mixer pod, before transport to the work area. The conveyer may be used underground to 20 transfer powder to the mixer pod during use. The mixer pod may be equipped with the normal QDS attachment, as well as an additional wider connection interface to enable carriage by the hopper pod. 25 Each mixer may incorporate an operator activated dust suppression system for use at least while the grout powder is being transferred to the mixer. The two mixers may be air operated mixer and pump units, which can be used simultaneously for continuous grout mixing and pumping, and are hinged for cleaning 30 purposes. Alternatively, one mixer can be used for mixing it's contents, while the mixed contents of the other is being pumped to the cable bolts. The envisaged process using the Bulk Grout System comprises the following: First, the hopper is filled with powder before transport to the work area. 35 Next, the hopper pod is transported with or without the mixer pod to the work area..

4 Once the Bulk Grout System has been delivered to the desired work area, it is set down and connected to pneumatic and hydraulic supply lines. The hydraulic line provides water for the mixers, and the pneumatic line provide power for agitation and transfer of the powder to the mixers, for mixing the powder and 5 water, and for pumping the mixed grout to the cable bolts. The powder may be conveyed from the hopper by the conveyor into one or both mixers. 10 A dust suppression system may be activated whilst conveying the powder. Once the correct amount of powder has been added to the mixers, the screw conveyor and dust suppression system are turned off. 15 Next, the fill-water for at least one Mixer is turned on, water enters as the mixers are mixing until the required ratio of water and powder is achieved. A filling system assists operators in reaching the desired water/powder ratio. 20 After the required ratio of powder-to-water has been added to the mixers, the fill-water is turned off, but the mixer continues operating until the powder and water have been mixed into grout and the correct viscosity is attained. Once the grout has the correct viscosity, one or both of the pumps are activated to 25 pump the grout to the bolts. By having two mixer and pump units available, both pumps may operate at the same time. Alternatively, the option of having one unit mixing while the other is pumping is also available. This option enables a continuous supply of grout for the bolting 30 applications. The process described here offers a combined continuous process of storage, transport, handling, mixing, and pumping. 35 It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing 5 from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. One or more advantages of at least one embodiment includes: 5 * Provide at least the same or better grout storage, transport, handling, mixing, and pumping procedures compared to conventional procedures; " Provide an avenue to resolve grout quality issues and improved grout performance by achieving better powder-to-water mixture ratios; " Be logistically simpler than conventional grouting and reduce manual handling, 10 and; " Reduce the number of safety risks and hazards which exist in conventional procedures by preventing manual handling and suppressing airborne dust particles. 15 The combination of the abovementioned equipment enables storage, transport, handling, mixing, and pumping of strata support grout in underground coal mining applications. The system as a whole is a revolutionary concept in the mining industry that dramatically reduces manual handling, safety risks and hazards, and increases productivity. 20 Brief Description of the Drawings An example of the bulk grout system and its modes of operation will now be described with reference to the accompanying drawing, in which: 25 Fig. 1 is a pictorial view of a Bulk Grout System Best Mode 30 The Bulk Grout System 10 comprises a hopper pod 12 and a mixer pod 14. Interlocking formations 16 and 18 allow the two pods 12 and 14 to be releasably interconnected so they can together be carried to the work area, and out again, using an appropriate load haul and dump vehicle. 35 It is preferred that the hopper pod 12 cannot pick up any equipment except the mixer pod 14, and the formations 16 include horns that have intentionally been made wider 6 than normal to prevent interconnection with other equipment. The hopper 12 has a capacity of 1.5 cubic meters, and is filled, before transport to the work area, with sufficient grout for the entire shift. Air operated screw conveyor 20 is connected between the hopper pod 12 with the mixer pod 14, before transport to the work area. 5 The conveyor 20 is used underground to transfer powder to the mixers 22 and 24 during use. The mixer pod 14 has the normal QDS attachment, as well as the additional wider connection interface 18. This allows the mixer pod 14 to be handled by suitable 10 vehicles, and by the hopper pod 12. The mixer pod 14 carries two mixers 22 and 24. Two pumps 30 and 32 are also provided on the mixer pod 14, one for each respective mixer 22 and 24. Each mixer incorporates an operator activated dust suppression system for use at least 15 while the grout powder is being transferred to the mixer. Each of the two mixers 22 and 24 include a water-filling system to monitor the amount of water entering the mixer and ensure accuracy in achieving the desired grout-to-water ratio; this produces a better product output and thus better bolt performance. 20 The two mixers 22 and 24 are air operated mixer and pump units, which can be used simultaneously for continuous grout mixing and pumping, and are hinged for cleaning purposes. Alternatively, one mixer can be used for mixing it's contents, while the mixed contents of the other is being pumped to the cable bolts. 25 The system has been designed primarily so it can typically produce enough mixed grout to last an entire shift at an underground coal mine. After this shift is over, the empty hopper is transported back to the surface and either re-filled, or replaced with a pre filled hopper. This allows a reduction in the intensity and duration of manual labour required to complete the operation; leading to reduced operation costs and increased 30 mine-site productivity. The system facilitates storage, transport, handling, mixing, and pumping of strata support grout. Once the bulk grout system has been delivered to the work area by the vehicle, it is set down and connected to pneumatic and hydraulic supply lines. The hydraulic line 35 provides water for the mixers, and the pneumatic line provide power for transfer of the 7 powder to the mixers, for mixing the powder and water, and for pumping the mixed grout to the cable bolts. The cable bolting process is then carried out in the following steps: 5 The powder is conveyed from the hopper 12 by the screw conveyor 20 into the mixers 22, 24; having the dust suppression system activated whilst conveying the powder. Once the correct amount of powder has been added to the Mixers 22, 24, the screw conveyor 20 and dust suppression is turned off. 10 Next, the fill-water to at least one mixer is turned on. Water enters as the mixers are mixing until the required ratio of powder-to-water is achieved; the system assists operators in reaching the desired powder-to-water ratio. 15 After the required ratio of powder-to-water has been added to the mixers, the fill-water is turned off, but the mixer continues operating until the powder and water have been mixed into grout and the correct viscosity is attained. Once the grout has the correct viscosity, one or both of the pumps 30 and/or 32 are 20 activated to pump the grout to the bolts. By having two mixer and pump units available, both pumps may operate at the same time. Alternatively, the option of having one unit mixing while the other is pumping is also available. This option enables a continuous supply of grout for the bolting applications. 25 The process described here offers a combined continuous process of storage, transport, handling, mixing, and pumping. It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing 30 from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. For instance the hopper pod may carry more or less than the 1.5 cubic meters of powder stated.

Claims

1. A bulk grout system comprising a hopper pod and a mixer pod, having interlocking formations to allow the two pods to be releasably interconnected for 5 transport as a single unit; wherein there is a closed compartment inside the hopper pod that is filled with powder before transport to the work area; and, the mixer pod carries two air operated mixers and two air operated pumps, one for each respective mixer. 10

2. A bulk grout system according to claim 1, wherein the two mixers include a system to monitor the amount of water entering the mixer and assist in achieving the desired powder-to-water ratio; and wherein in use an air operated transport is used to selectively transfer powder from the hopper to the mixers. 15

3. A bulk grout system according to claim 1 or 2, wherein interlocking formations of the hopper pod include horns to prevent it from connecting to any equipment except the mixer pod. 20

4. A bulk grout system according to claim 1,2 or 3 wherein an air operated conveyor is connected between the hopper pod and the mixer pod, before transport to the work area, and the conveyer is used underground to transfer powder to the mixer pod during use. 25

5. A bulk grout system according to any preceding claim, wherein the mixer pod is also equipped with a QDS attachment.

6. A bulk grout system according to any preceding claim, wherein each mixer incorporates an operator activated dust suppression system for use at least while the 30 grout powder is being transferred to the mixer.

7. A bulk grout system according to any preceding claim, wherein the two air operated mixers include pump units, which can either be used simultaneously for continuous grout mixing and pumping, or, one mixer can be used for mixing while the mixed 35 contents of the other is being pumped. 9

8. A method for operating the bulk grout system of claim 1, comprising the steps of: first, the hopper is filled with powder before transport to the work area; next, the hopper pod is transported with or without the mixer pod to the work area; 5 once the bulk grout system has been delivered to the desired work area, it is set down and connected to pneumatic and hydraulic supply lines; the hydraulic line provides water for the mixers, and the pneumatic line provide power for agitation and transfer of the powder to the mixers, for mixing the powder and water, and for pumping the mixed grout to the cable bolts; 10 the powder is conveyed from the hopper by the conveyor into one or both mixers; a dust suppression system may be activated whilst conveying the powder; once the correct amount of powder has been added to the mixers, the screw conveyor and dust suppression system are turned off; 15 next, the fill-water for at least one mixer is turned on, so that water enters as the mixers are mixing until the required ratio of water and powder is achieved; a filling system assists operators in reaching the desired water/powder ratio; after the required ratio of powder-to-water has been added to the mixers, the fill water is turned off, but the mixer continues operating until the powder and water have 20 been mixed into grout and the correct viscosity is attained; once the grout has the correct viscosity, one or both of the pumps are activated to pump the grout to the bolts.