MINE SHAFT

The present invention concerns an arrangement and a method for the lining of a mine shaft where the lining operation is remotely controlled from a location outside of the shaft.

Vertical shafts, or essentially vertical shafts, are excavated for various purposes in mining. A shaft that has been excavated should be provided with a lining in order to stabilise the excavated surfaces, and to seal the shaft against water that may leak into the shaft through cracks. The lining operation takes place through wet concrete being sprayed onto the walls of the shaft with the aid of a concrete sprayer. The concrete sprayer is fed with concrete from a pump that is located at the shaft opening. The feed of concrete takes place through tubes and pipes that lead the pressurised concrete to the sprayer. At the start of the work, the sprayer is lowered to the bottom of the shaft together with a lift car and personnel, after which the lift car, with the sprayer and personnel, is raised upwards through the shaft. The sprayer is manoeuvred during the transport upwards such that the walls of the shaft are coated with concrete.

The disadvantages of this method are, among other things, that personnel who are present in the lift car are in a dangerous environment, and are subject to concrete splatter. Furthermore, it is difficult for personnel to coat the walls with an evenly thick layer of concrete, and at the same time check that the complete wall of the shaft is coated.

The purpose of the present invention, therefore, is to achieve an arrangement and a method to avoid the said disadvantages by offering an arrangement that coats the walls of the shaft with concrete in a controlled manner such that the layer of concrete covers the surface completely and evenly. One further purpose is to prevent personnel being present in the dangerous environment that the shaft constitutes during the lining operation.

This is achieved through a shaft lining arrangement and a method for carrying out lining with such an arrangement according to the present invention that demonstrates the characteristics specified in the attached patent claims.

The invention will be described below with reference to the attached drawings, of which:

Figure 1 shows a cross-section of a shaft excavated in rock,

Figure 2 shows an overview of an arrangement according to the invention, and

Figure 3 shows a detailed view of an arrangement seen from the side.

Figure 1 shows a cross-section of a shaft 1 excavated essentially vertically in rock 2. The shaft extends from an upper plateau 3, through the rock 2 and down to a lower plateau 4. These plateaux 3, 4 may constitute different levels of the shaft, and the shaft 1 that has been excavated may be used for the assembly of a lift for the transport of at least one of material and personnel, or it may be used as a spoil shaft through which mined ore and mined rock can be tipped from the upper plateau to the lower plateau for further handling.

A frame 6, for example a hoisting frame, is arranged at the shaft opening 5 in association with the upper plateau 3, as seen in Figure 2. This comprises at least three legs 7 that rest on the floor 8 of the plateau 3. It is an advantage that the frame 6 is located centrally over the shaft opening 5, with a running wheel L. A control wire 9, three tubes 10 and cables 11 from a control centre 12 run to the frame 6. The tubes 10 lead pressurised air and wet concrete under pressure, while the cables 11 lead electrical power and data for communication. The control centre 12 comprises a pump 13 for the pumping of concrete and accelerator, a compressor 14 for the pressurisation of air, regulators 15, a monitor 16 and a winch 17.

The tubes and cables 10, 11 are located wound unto a drum 18, together with the wire 9. The speed of winding of the drum 18 is regulated by the control centre 12, and it is synchronised with the speed of the winch 17. The tubes 10 are connected to a source 20 of liquid concrete, such as a concrete mixer or a concrete pump at a concrete tanker, and to a source of an accelerator. The accelerator comprises a material that accelerates the hardening of the concrete. The cables 11 are fed with electrical power from an electrical supply that is present in the mine. The tube 10 is attached to the wire 9 in order to be able to support the weight that arises from the concrete that is present in the tube when it is used.

The winch 17 comprises in the customary manner a frame with a drum on which the control wire 9 is wound, a motor 22 for driving the drum 18, and electronic circuits for the control of speed, direction and winding of the control wire.

The control wire 9 runs from the winch 17 via the frame 6 over the running wheel L and down into the shaft 1, and an arrangement 23 is suspended from the control wire 9 at one of its ends 24. The arrangement 23, which is shown in Figure 3, comprises an extended frame 25, into which the tubes 10 and cables 11 run, into one end 24 of the frame 25. The tubes 10 may be connected to the frame with the aid of rapid-release connectors 26, or they may be mounted with bayonet connectors or screw caps. The cables 11 are connected to the arrangement 23 with the aid of contacts 27.

At the second end 28 of the arrangement 23, the end that is located furthest from the wire 9, there is arranged a rotating outlet or a swivel 29, with a nozzle 30 through which concrete is sprayed. The swivel 29 is connected to the flow of air, concrete and accelerator from the tubes 10. A tube 31 that is bent at an angle runs from the swivel 29, and the nozzle 30 is located at the free end 32 of the tube. The bend of the tube 31 is designed in such a manner that the concrete that is sprayed out is directed towards the wall S of the shaft. The swivel 29 is so designed that when the pressurised air is led through the swivel 29, the latter starts to rotate around the centre line 33 of the shaft 1 and the arrangement 23. The tube 31 accompanies the arrangement in the rotation.

Means 35 for the positioning of the arrangement 23 in the shaft 1 are located at the frame 25 of the arrangement, at its sides 34. The means 35 comprise a number of extended supports 36, with a length that corresponds to the length of the arrangement 23. It should be realised that the supports 36 may be longer or shorter than the arrangement 23, or they may be divided into several pieces located in a line one after the other along the extension of the arrangement 23. It is an advantage if the supports 36 are evenly distributed around the circumference of the arrangement 23, with, for example, one support 36 at each side 34 of the arrangement 23.

At least one of the supports 36 is attached to the arrangement 23 in a jointed manner. The jointed attachment 37 is so designed with link arms 38 that the support 36 can be manoeuvred in the direction towards or away from the arrangement 23 as shown by the arrows in Figure 3, towards or away from the wall S of the shaft, in a motion that is parallel to the arrangement 23. In other words, the distance between the arrangement 23 and the relevant ends of the support 36 increases and decreases during the complete motion. The manoeuvring takes place with the aid of control means 39 in the form of hydraulic cylinders 40 connected to a hydraulic unit arranged in the arrangement (not shown in the drawings). The cylinders may also be pneumatic, and are in this case driven by a compressor at the arrangement or through lines from a compressor at the control centre. The cylinders may also be electrically driven, by the power supply.

It is an advantage if the ends 41 of the supports 36 are provided with a bend or angle 42 in towards the arrangement 23, such that the profile of the support 36 resembles a ski. The advantage of this is that the risk that the support 36 becomes stuck in the wall S of the shaft during the motion of the arrangement 23 is reduced.

It is an advantage if the supports 36 are arranged with wheels 43. The wheels 43 are arranged at a wheel axle 44 in a manner that allows rotation, which wheel axle 44 is located in the support 36 in such a manner that the circumference 45 of the wheel 43 is located further away from the arrangement 23 than the support 36. The advantage of this is that the wheel 43 first makes contact with the wall S of the shaft and prevents that the support 36 is subject to wear, while the support 36 at the same time guides the arrangement 23 in the shaft 1. The support may be provided also with a surface layer on the side that faces the wall of the shaft, in order to facilitate its sliding against the wall. The surface layer may comprise a plastic coating or similar durable material.

Also a means 46 to monitor the concrete that is sprayed against the wall S of the shaft is arranged at the arrangement 23. The means in this embodiment comprises a camera 47. The camera may be of the type that takes stationary images, or it may be a film camera. The camera is connected to the contacts for the feed of electrical power, or it may be battery-powered. The connection comprises also communication to the control centre for the delivery of the images or films that are recorded. There is arranged at the camera also a splash protector 48 in the form of a roof, in order to prevent concrete falling onto the camera lens and preventing images from being taken. Illumination 49 intended to illuminate the region that is to be imaged by the camera is arranged in association with the splash protector. The illumination is in the form of a spotlight or a light fitting, and it is located such that it also is protected by the splash protector.

Data containing the images or films are transferred through communication cables 11 to the monitor 16 of the control centre 12. Other transfer can take place through wireless transfer, such as WiFi, bluetooth or similar technology. An operator (not shown in the drawings) can monitor the result of the lining operation, and can determine and adapt with the aid of the images the speed with which the arrangement 23 is raised, the pressure at which the concrete is sprayed from the nozzle 30, and the direction in which the arrangement 23 is manoeuvred. If the operator discovers that a part of the wall S of the shaft lacks lining, or that the lining is of inferior quality, the operator can stop the upwards journey of the arrangement 23, and change the direction of transport through regulators 15 of the control centre 12, such that the area of the inferior lining can be treated again.

When the operation to line the shaft starts, the arrangement 23 is located suspended from the frame 6 in line with the centre line 33 of the shaft, as shown in Figures 1 and 2. The operator controls the arrangement 23 from the control centre 12, and lowers the arrangement 23 downwards in the shaft 1. During the downwards motion, the drum 18 on which the wire 9, electrical cables 11, communication cables and tubes 10 are wound is rotated. The arrangement 23 is manoeuvred to the bottom 50 of the shaft 1. Motion is stopped when the arrangement 23 reaches the bottom 50. The supports 36 are manoeuvred in the direction towards the wall S of the shaft, until the supports 36 are located in close association with the wall S of the shaft.

The arrangement 23 subsequently starts to be raised upwards, while the concrete pump 20 is started. Wet concrete under pressure is pumped through the tube 10 to the arrangement 23, through the swivel 29, through the tube 31 and out through the nozzle 30. The swivel 29 starts to rotate with the aid of pressurised air as the concrete passes the swivel. This rotation may cause the arrangement 23 to oscillate. This oscillation is efficiently prevented by the supports 36, while the arrangement is at the same time centred in the shaft. The speed with which the arrangement is raised upwards is regulated by the operator, who monitors the result through images that are displayed on the monitor, and the operator adapts the speed taking into consideration the amount of concrete and the pressure at which the concrete is led to the arrangement. If the amount and pressure are large, the arrangement can be raised more rapidly than is the case when the amount and pressure are small. The shape of the shaft 1 may change or the centre line 33 of the shaft 1 may oscillate during the journey of the arrangement 23 upwards through the shaft. This change may mean that the supports 36 must be manoeuvred in the direction towards or away from the wall S of the shaft. Protruding parts of the wall S of the shaft may become lodged in the supports 36 of the arrangement 23 at such a change of shape. If this takes place, the support can be manoeuvred in the direction towards the arrangement 23 such that the arrangement becomes free. The supports 36 are used also to centre the arrangement 23 if necessary.

The present invention is not limited to what has been described above and shown in the drawings: it can be changed and modified in several different ways within the scope of the innovative concept defined by the attached patent claims.