Editorial Note for 2009100717 The description commences at page number 2.
2 An apparatus for controlling the flow of ventilation air in mining environments FIELD OF THE INVENTION The present invention relates to an apparatus for controlling the flow of ventilation air in mining environments and, in particular, in mining ventilation ducts to 5 prevent or at least reduce the flow of air to various areas inside the mine. BACKGROUND OF THE INVENTION Mining has long been considered to be a lucrative and yet a dangerous occupation. For that reason there are many facilities provided in mines to ensure that there is no danger to life and that necessary facilities are provided. 10 One of the most obvious requirements in any mine is that the air must be maintained to an acceptable standard. Given that mines can be many kilometres in length, most underground mining installations include ventilation ducts that travel along the tunnels to provide air where it is necessary. Typically, most such ducts are of a generally cylindrical shape and are hung from the roof of the tunnel. 15 Many mines have multiple tunnels extending underground and in some cases a central tunnel will split into two separate tunnels extending in different directions, for example, using T-piece and Y-piece ducting. Each of these tunnels needs to be provided with its own ventilation, Some tunnels also require two ducts which are hung adjacent one another, either separately, or sharing a common wall. 20 A problem which currently exists is that ventilation air may be required in one part of the mine but not necessarily in another, or perhaps less ventilation air is required in one area compared to another. For whatever requirement, there is a need to be able to control the amount of ventilation air to particular parts of a mine. It is an object of the present invention to overcome at least some of the 25 aforementioned problems or provide the public with a useful alternative. The present invention successfully addresses these problems by providing an inflatable stopping which may be fitted at any point along a mine ventilation duct, the stopping adapted to be controllably inflated and deflated by high pressure air supply which is already present in most mines so as to minimise, maximise, or completely 30 prevent the flow of air through that point in the duct. SUMMARY OF THE INVENTION 3 Therefore, in a first aspect the invention could be set to reside in a stopping apparatus for use in a ventilation ducting system for mines including a main ventilation duct, said stopping apparatus including an inflatable body disposed outside of said main ventilation duct, said body being inflatable from a fully deflated state in which air is 5 allowed to flow through said main duct, to a fully inflated state in which the body pinches the main duct to an extent which substantially prevents the flow of air there through, and vice versa. Preferably the supply of air to said inflatable body is controllable, allowing for partial inflation and deflation of said body. 10 In preference said inflatable body is supported outside of said body in a position which enables is to pinch the main duct when in the inflated state using a harness configured to be fitted to any position along the main duct. In preference said main duct includes a circular cross section, and said inflatable body is cylindrical and when expanded has substantially the same cross sectional 15 dimension as that of the main duct. In a further form of the invention there is proposed a ventilation ducting system for use in mines comprising: ductwork including at least one primary duct which separates into two or more secondary ducts; 20 stopping apparatus fitted to each of the two or more secondary ducts downstream of the junction between the primary duct and the secondary ducts, each stopping apparatus including an inflatable body disposed outside of said ductwork, said body being inflatable from a fully deflated state in which air is allowed to flow through the respective secondary duct, to a fully inflated state in which the body pinches the 25 respective secondary duct to an extent which substantially prevents the flow of air there through, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with 30 the description, serve to explain the advantages and principles of the invention. In the drawings: 4 Figure 1 illustrates a perspective view of a straight mining ventilation duct carrying air, including a deflated stopping apparatus fitted on the outside of the duct in accordance with the present invention; Figure 2 illustrates a perspective view of the straight ventilation duct of 5 Figure 1 and stopping apparatus which is partly inflated, thereby reducing airflow through the duct; Figure 3 illustrates a perspective view of the straight ventilation duct of Figure 1 and stopping apparatus which is fully inflated, thereby preventing airflow through the duct; 10 Figure 4 illustrates a cross sectional view of the ventilation duct and deflated stopping apparatus of Figures 1; Figure 5 illustrates a cross sectional view of the ventilation duct and partially inflated stopping apparatus of Figure 2; Figure 6 illustrates a cross sectional view of the ventilation duct and fully 15 inflated stopping apparatus of Figure 3; and Figure 7 illustrates a perspective view of a T-piece mining ventilation duct, including a stopping apparatus fitted downstream of the T-piece junction and being fully inflated to thereby divert all airflow through the perpendicular duct of the T-piece. 20 DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the 25 same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Turning now to the Figures in detail and specifically to Figures 1-3 there is shown an inflatable apparatus 10 fitted around the outside of a single, cylindrical straight duct 12, which will be described in more detail below. Air 14 flows through the 30 duct 12. Each end of the duct, which could be of any reasonable length, includes a spigot 16 that includes eyelets 18 that enable the duct to be joined to other ducts to make 5 up a long ventilation system. The joining may be accomplished by various means, such as a rope (not shown) that ties two spigots together through the eyelets. To ensure a good seal, sealing joints (not shown) may be used to extend between ducts to be joined together. The sealing joints are typically some 500 millimetres in 5 length and so extend 250 millimetres into each duct. The vertical extent of duct 12 is typically around 1 metre. In use, the ventilation duct 12 is supported by ties (not shown) that engage eyelets 20 spaced apart along a hanging fin 22 from which the duct 12 is suspended. The ties (not shown) are usually attached to a supporting cable (not shown). To provide for 10 strength and durability the duct is made from woven polyethylene fabric extrusions coated with a low resistance film. As mentioned in the preamble of the invention, there is a need sometimes to prevent or at least minimise the flow of air 14 through the duct 12 in mining environments. The present invention addresses this issue through use of the stopping 15 apparatus 10. The stopping apparatus 10 includes a harness 23 adapted to be wrapped around the outside of the duct 12, the harness 23 also including means to be attached to and suspended from the hanging fm 22. The harness 23 is used to support a short length of cylindrical duct body 24 on the outside of the main duct 12. The duct body 24 has two circular ends 26, and shares 20 substantially the same dimension as the main duct 12 to ensure complete blocking of the duct 12 when the body 24 is fully inflated. It is to be understood however that the stopping need not necessarily be this shape. The most important concern is that when in the fully inflated state, the body 24 has the same cross sectional dimension as that of duct 12, which could be square for example rather than circular. 25 Therefore, where for example maximum air flow is required through duct 12, the body 24 is adapted to lie deflated in the harness so as not to alter the cross section of the duct 12 at all. This is shown clearly in Figure 1 and Figure 4. Figure 2 and Figure 5 illustrate the stopping apparatus body 24 partially inflated and causing the duct 12 to compress to a portion of its maximum cross section, for when less air is required at the 30 duct destination. Figure 3 and Figure 6 show the body 24 fully inflated and thereby pinching the main duct 12 to an extent which blocks almost completely the flow of air there through.
6 Air can be supplied to the stopping apparatus body 24 through any known means, however, in preference air is sourced from the high pressure air supply which is typically found in most mines. In the embodiments shown, an air compressor 28 is used, including a hose 30 which is adapted for connection to a valve 32 associated with an end 5 26 of the stopping body 24. The present invention is however not intended to be limited to any one method of supplying air to inside the stopping 10. The supply of air to inside the stopping body 24 is also intended to be controllable so that the extent to which the body 24 is inflated or deflated can be easily controlled. It is envisaged that at every stopping location along a ventilation duct in a 10 mine, there will be a manual means (not shown) of regulating the flow of air through that part of the duct 12. Again, this could be achieved using any known air flow regulation means including air flow valves and the like. It is also envisaged that such control will be possible from a remote location, for example, at a central mine workstation where all tunnels are mapped, and air flow to each mine location can be 15 controlled by the push of a button. Figure 7 illustrates a T-piece 36 including a straight first duct 38 and a second duct 40 extending perpendicularly therefrom so that the air 14 is split into two paths. Such ducting is required where a mine tunnel forms a T-junction and obviously ventilation air needs to be supplied along both paths. 20 Like reference numerals have been used on parts of the T-piece 36 which have already been described in connection with duct 12. A stopping apparatus 10 is shown fitted around the straight duct 38 just downstream of the perpendicular duct 40. It is envisaged that every T-piece 36 in a ventilation system would include a stopping apparatus 10 arranged like so, so that when 25 the body 24 is inflated fully, all air is diverted into the perpendicular duct 40. Although not shown, duct 40 would also include a stopping 10 fitted adjacent the junction, so that when that body (not shown) is fully inflated, all air will continue down duct 38. The same would apply to bifurcated ducts (not shown) in the system, and so on. For the purposes of the specification the word "comprising" means "including 30 but not limited to", and the word "comprises" has a corresponding meaning. Also a reference within the specification to document or to prior use is not to be taken as an 7 admission that the disclosure therein constitutes common general knowledge in Australia. Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and 5 described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. 10