GB2111930A - Particulate solid material supply system and method - Google Patents

Abstract

Particulate solid material (e.g. cement) is stored in a main downpipe 17 extending into a vertical mine shaft 10 from which tunnels 11 and 12 extend and can be readily fed into the tunnels 11 and 12 through branch pipes 19 without delay and without causing heavy wear. The downpipe 17 is fed from a silo 13 via a supply hopper 15 gravity feeding a further hopper 16 when the cement in the latter reaches a predetermined level. <IMAGE>

Description

SPECIFICATION Particulate solid material supply system and method This invention relates to a system and method for supplying particulate solid material to mines and other locations where particulate solid material is required to be supplied a considerable distance downwardly. It is envisaged that the system and method of the present invention could be applicable to undersea operations.

It has recently been proposed to supply cement into a mine by feeding cement from a silo at the surface to a different levels in a mine using a pneumatic conveying system to blow from the silo down a vertical main pipe into the mine. The cement is then selectively diverted from the main pipe into a branch pipe at the required level leading to a hopper at that level wherein the cement is temporarily stored prior to use before being again pneumatically or mechanically conveyed to the point of use.

Since mine shafts normally run vertically, and the vertical distance through which the material is to be pneumatically conveyed can be up to perhaps 2000 metres, one of the main problems with this system is that the cement will travel faster than the conveying airstream and can reach very high velocities, (of the order of 200 mph). This has the disadvantage that very heavy wear occurs, particularly at the location where the cement is diverted into the branch pipe. Also, with this type of system there is a requirement for a underground storage hopper at each level and also a requirement for an underground pressure vessel in view of the pneumatic conveying system employed. This is expensive and such equipment occupies space underground.

It is an object of the present invention to obviate or mitigate the above disadvantages.

According to the present invention, there is provided a particulate solid material supply system for a mine or other location where the material is required to be supplied a considerable distance downwardly, said system comprising storage means including an extended length of pipe which, in use, extends downwardly in said mine or at said other location and in which length of pipe solid particulate material is stored in use, and selectively operable means for feedihg solid particulate material from said pipe.

Thus, for example, in a mine in which the downwardly extending pipe runs for only 1000 feet, a 10" diameter downpipe would have a capacity of over 20 tonnes of cement.

Larger capacities can be obtained by linking the downpipe directly to an upper silo.

With a system according to the present invention, the rate of flow of solid particulate material through the downpipe when the system is in operation is very much less than the above described previous proposal using a pneumatic conveying system. Because the downpipe is filled with particulate solid material at all times (except of course when being initially charged), there is facility for an individual supply of such material to each level. Thus, the need for one or more individual temporary hoppers fed by the downpipe is obviated.

In circumstances where there is a risk of the solid particulate material becoming blocked in the downpipe, it is within the scope of the present invention to provide appropriate discharge aids of the mechanical or pneumatic type, and/or to use a downpipe made up of a number of relatively easily removable sections.

In a preferred embodiment, where material is to be conveyed into a branch pipe from the downpipe, a pneumatic system may be employed. For example, air may be forced into the downpipe at a location just above the branch pipe to force the material into the latter. If desired, mechanical conveying means may be provided.

Also according to the present invention there is a provided a method of supplying particulate solid material to a mine or other location where the material is required to be supplied a considerable distance downwardly, comprising the steps of providing a downwardly extending pipe in the mine or at said other location, filling said pipe with solid particulate material so that said solid particulate material is stored in said pipe, and periodically transferring said solid particulate material from said pipe into a branch pipe or the like.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic illustration of a particulate solid material supply system according to one embodiment of the present invention, and Figure 2 is a schematic view of part of the system illustrated in Fig. 1.

Referring to the drawings, the particulate solid material supply system is for a mine having a vertically extending shaft 10 and a plurality of tunnels extending laterally therefrom at different levels. The system includes a silo 1 3 which contains cement, although it may contain aggregate material if such is required in the mine. The silo 1 3 is connected via a pipe 1 4 with a supply hopper 1 5 which gravity feeds cement into a further hopper 1 6 when the cement in the latter drops below a predetermined level. The further hopper 1 6 is directly connected to a vertical pipe 1 7 which extends for a considerable distance down the mine shaft to the level of all of the tunnels, typically shown at 11 and 12.In this embodiment, the diameter of the pipe 1 7 is about 10" and extends for 2000 to 3000 feet vertically downwardly. Of course, the length of the pipe 1 7 depends upon the depth of the mine. At the level of each tunnel 11, 1 2 there is provided a respective transfer device 1 8 which is shown in Fig. 2.Each transfer device 1 8 serves to supply cement from the pipe 1 7 to a horizontal branch pipe 1 9 extending to the required location in the respective tunnel 11, 1 2. Each transfer device includes a downwardly tapering frusto conical manifold 20 which surrounds the pipe 1 7 but communicates therewith through an aperture 21 in the side wall of the pipe 1 7. In practice, however, such a manifold 20 may be provided by forming the pipe 1 7 in a number of sections which are axially spaced apart to define the openings 21 and which have the manifold 20 secured to one end thereof.The transfer device 1 8 further includes a first valve 22 which is disposed in the pipe 1 7 below the manifold 20 and the branch pipe 19, and a second valve 23 which is disposed in the branch pipe 1 9 adjacent the manifold 20. Each device 1 8 further includes a first air supply pipe 24 leading to the manifold 20 from a main air pipe 25, and a second air supply pipe 25 leading from the pipe 24 to the branch pipe 1 9 downstream of the second valve 23. The supply from pipe 25 to the pipes 24 and 26 via a common brach section 25a which restricts the flow of air from the pipe 25 to the pipes 24 and 26. A pressure regulator 27 is disposed between the first and second air supply pipes 24 and 26.

In use, the system is charged by supplying cement from the silo 1 3 to the main downpipe 1 7 via the hoppers 1 5 and 1 6 so that the whole of the length of the pipe 1 7 is completely filled with cement. It will be appreciated that by this means a considerable quantity of cement is stored within the pipe 1 7 and that this cement can be readily drawn off into the required tunnel 11, 1 2 by operation of the appropriate transfer device. In order to transfer cement from the pipe 1 7 to the branch pipe 19, valve 22 is closed. Then, air is supplied from the main air pipe 25 to the first and second pipes 24 and 26 under the control of a valve (not shown).As a result of supply of air through pipe 24, the pressure in the manifold 20 rises and, when valve 23 is opened, this causes the cement to be transferred from the main pipe 1 7 through the valve 23 and into the branch pipe 1 9. Flow of cement along the branch pipe 1 9 is promoted by air passing into the pipe 1 9 from air supply pipe 26.The pressure regulator 27 controls the air pressure as between the pipes 24 and 26 so that if the air pressure in line 1 9 is low, which is indictive of little restriction to flow along the pipe 19, the valve 27 operates to decrease the pressure in the pipe 26 and to increase the pressure in pipe 24 so that a greater flow of cement from the pipe 1 7 to the branch pipe 1 9 is promoted. On the other hand, if the pressure in pipe 26 rises, for example because of too great a supply of cement thereto or because of a blockage, then valve 27 causes the the pressure in pipe 24 to be reduced an- that in pipe 26 to be increased.

When flow of cement through the selected branch pipe 1 9 is to be stopped, the supply of air to pipes 24 and 26 is turned off, pipe 23 is closed and pipe 22 is opened so that tunnels at lower levels can be supplied with cement.

It will be a, zreciated that as cement is drawn off from? pipes 17, it is continuously replenished from the hopper 1 6 supplied with cement via hc per 1 5 and silo 1 3. Thus, the pipe 1 7 is always kept full of cement and thereby erosion in the region of the transfer devices 1 8 is very much less than would be the case if cement were pneumatically supplied down the pipe 1 7.

As shown in Fig. 2, the pipe 1 7 is formed of a number of flanged sections which are bolted together. At spaced locations along the length of the pipe 17, there are provided a plurality of air inlets of which one is typically shown at 29. Air is introduced into the pipe 1 7 in the event of a blockage ocurring. It is envisaged that build up of pressure above the blockage by introduction of air through one of the inlets 29 will be sufficient to clear any blockages. However, any serious blockages which cannot be cleared in this way can be manually cleared by removing the section of pipe 1 7 in which the blockage occurs and clearing it manually. As an alternative to pneumatic clearing of blockages, it is within the scope of the present invention to clear blockages by mechanical means, eg. a discharge aid device which is disposed within the pipe 1 7 and which is rotated~and/or vibrated.

Claims (7)

1. A particulate solid material supply system for a mine or other location where the material is required to be supplied a considerable distance downwardly, said sytem comprising storage means including an extended length of pipe which, in use, extends downwardly in said mine or at said other location and in which length of pipe solid particulate material is stored in use, and selectively operable means for feeding solid particulate material from said pipe.

2. A system as claimed in Claim 1, wherein a discharge aid of the pneumatic or mechanical type is provided to prevent particulate material becoming blocked in the downpipe.

3. A system as claimed in claim 1 or 2, wherein, the pipe is made up of a number of relatively easily removable sections.

4. A system as claimed in Claim 2, wherein where material is to be conveyed into a branch pipe from the downpipe, a pneumatic type of discharge aid is provided to force air into the downpipe at a location just above the branch pipe wherein in use the material is forced into the latter.

5. A method of supplying particulate solid material to a mine or other location where the material is required to be supplied a considerable distance downwardly, comprising the steps of providing a downwardly extending pipe in the mine or at said other location, filling said pipe with solid particulate material so that said solid particulate material is stored in said pipe, and periodically transferring said solid particulate material from said pipe into a branch pipe or the like.

6. A system as claimed in claim 1, substantially as hereinbefore described with reference to the accompanying drawing.

7. A method as claimed in claim 5, substantially as hereinbefore described with reference to the accompanying drawings.