AU2018100278A4 - Fluid supply control system - Google Patents

Abstract

H:\stp\Interwoven\NRPortbl\DCC\STP\ 6514803 _.docx-22/02/2018 -9 A control system for controlling supply of pressurized fluid via a pressurized feed line, the control system including: a fluid operated control valve positioned in the feed line to selectively control flow of fluid through the feed line; a pilot line coupled to the feed line upstream of the control valve and extending to the fluid operated control valve; and a timer valve provided in the pilot line, the timer valve being operating to selectively provide fluid to the control valve to thereby control operation of the control valve and thereby at least one of: activate supply of pressurized fluid via the pressurized feed line after a predetermined time period; and deactivate supply of pressurized fluid via the pressurized feed line after a predetermined time period. 110 121 110.1 Fig. 1

Description

Background of the Invention [0001] The present invention relates to a control system for controlling supply of pressurized fluid via a pressurized feed line, and in one particular example to a control system suitable for controlling the supply of compressed air in an underground mine or other similarly hazardous environment.

Description of the Prior Art [0002] 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 acknowledgment or admission or any form of suggestion that the 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.

[0003] There are a number of circumstances in which the supply of pressurized fluid, such as air, is utilized to power or drive equipment. One frequent application of such technology is in underground mining where pressurized air is used to power equipment to avoid safety issues associated with the use of electrical power. In particular, the use of compressed air as opposed to electricity to power equipment reduces the chances of sparking, which can in turn lead to fire hazards.

[0004] Because of the nature underground mining, it is typical for a source of compressed air to be provided remote to the mining work area, with compressed air being supplied to the work area and then supplied to a number of different pieces of equipment. In order for this to function effectively, it is therefore typically necessary to have a continuous supply of compressed air. As the supply of air to equipment can always be effectively halted, this in turn leads to significant wastage of compressed air, further leading to increased operating costs.

[0005] By way of example, limestone dust is often used during mining to suppress coal dust and thereby reduce the risk of explosions. In such situations, limestone is typically deployed

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-22018100278 02 Mar 2018 by placing a pod containing the limestone dust in a working area and then applying compressed air to the pod to cause the limestone dust to be distributed. Once the limestone dust has been initially deployed compressed air is no longer required. However, dust levels within the working region may be hazardous for some time after dust deployment, meaning workers may be required to exit the working region during this time. Consequently it may be unfeasible to stop the flow of compressed air to the pod, as the pod cannot be accessed and as air is often required by other equipment, this can lead to a waste of compressed air.

[0006] As a result of issues similar to this, it is estimated that only twenty percent of generated compressed air is effectively used, leading to significant cost implications for mine operators. Accordingly, there is a need for a system that can control supply of compressed air to individual pieces of equipment whilst avoiding electronic control signal systems that can lead to fire hazards.

Summary of the Present Invention [0007] In one broad form, an aspect of the present invention seeks to provide a control system for controlling supply of pressurized fluid via a pressurized feed line, the control system including: a fluid operated control valve positioned in the feed line to selectively control flow of fluid through the feed line; a pilot line coupled to the feed line upstream of the control valve and extending to the fluid operated control valve; and, a timer valve provided in the pilot line, the timer valve being operating to selectively provide fluid to the control valve to thereby control operation of the control valve and thereby at least one of: activate supply of pressurized fluid via the pressurized feed line after a predetermined time period; and, deactivate supply of pressurized fluid via the pressurized feed line after a predetermined time period.

[0008] In one embodiment the control system includes a regulator provided in the pilot line between the feed line and the timer valve to regulate a fluid pressure in the pilot line.

[0009] In one embodiment the timer valve is actuated after a predetermined time period.

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-32018100278 02 Mar 2018 [0010] In one embodiment the control system includes: a secondary pilot line extending from the pilot line to a timer valve reset input; and, an exhaust valve for exhausting the timer valve to thereby reset the timer valve.

[0011] In one embodiment the exhaust valve is a secondary timer valve adapted to selectively reset the timer valve after a second predetermined time period.

[0012] It will be appreciated that the broad forms of the invention and their respective features can be used in conjunction, interchangeably and/or independently, and reference to separate broad forms is not intended to be limiting.

Brief Description of the Drawings [0013] Various examples and embodiments of the present invention will now be described with reference to the accompanying drawings, in which: [0014] Figure 1 is a schematic diagram of a first example of a control system for controlling supply of pressurised fluid; and, [0015] Figure 2 is a schematic diagram of a second example of a control system for controlling supply of pressurised fluid.

Detailed Description of the Preferred Embodiments [0016] An example of a control system for controlling supply of pressurised fluid via pressurised feed line will now be described with reference to Figure 1.

[0017] For the purpose of this example, it is assumed that the pressurised fluid is compressed air but it will be appreciated that the techniques could be applied to other fluids and could include any compressed gas or pressurised liquid and so reference to air is not intended to be limiting.

[0018] In this example, a system 100 for supplying compressed air includes a pressurised feed line 110, for supplying compressed air, as shown by arrow 110.1, and a control system

120 for controlling supply of pressurised fluid.

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-42018100278 02 Mar 2018 [0019] The control system 120 includes a fluid operated control valve 121 positioned in the feed line to selectively control flow of air through the feed line. The control valve 121 can be of any appropriate form and in one particular example is a pneumatic seat valve.

[0020] The system further includes a pilot line 122 coupled to the feed line 110 upstream of the control valve 121 and extending to the control valve 121. A timer valve 123, such as a pneumatic timer, which can be set to operate based on a predetermined delay, is provided in the pilot line 122 between the feed line 110 and the control valve 121, allowing the timer valve 123 to be used to selectively provide air to the control valve 121.

[0021] This arrangement can be used to control operation of the control valve 121, and in particular can be used to open or close the control valve 121 by supplying or stopping supply of air to the control valve 121 after a predetermined time delay, which in turn can be used to activate or deactivate supply of pressurised air via the pressurised feed line 110.

[0022] Thus, for example, when it is required to disburse limestone dust, a pod can be positioned in the working area and the timer 123 set to supply pressurised air to the control valve 121 for a set amount of time, such as 2 hours, as is required to distribute the dust. The system can then be activated allowing workers to vacate the area whilst the limestone dust is dispersed. Once sufficient dispersal has occurred, the timer will deactivate the supply of pressurised air to the control valve 121, causing the valve to close and halting the supply of compressed air, and hence obviating wastage of air whilst the limestone dust settles and before workers can return.

[0023] Alternatively, if workers are required to vacate an area prior to equipment being activated, the system can be configured to turn on the supply of pressurised air in a similar manner, simply by configuring the timer valve to only supply air to the control valve 121 after the time period has passed. In this regard, timer valves typically have two outputs, with functionality being swapped by attaching the pilot line to a particular one of the timer valve outputs, depending on the particular operation required.

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-52018100278 02 Mar 2018 [0024] In any event, it will be appreciated that the above described arrangement can therefore allow for increased safety and avoid excessive use of compressed air or other pressurised fluids.

[0025] A number of further features will now be described.

[0026] In one example, the control system can include a regulator provided in the pilot line between the feed line and the timer valve to regulate a fluid pressure in the pilot line. The regulator could be of any appropriate form and could include an air regulator with selfdraining water trap, bleed valve or the like.

[0027] In one example the timer valve is actuated after a predetermined time period. It will be appreciated that the time period can be adjusted depending on the intended usage of the control system, through suitable configuration of the timer valve.

[0028] The control system can also include a secondary pilot line extended from the pilot line, typically downstream of the pressure regulator, to a timer valve reset input, with an exhaust valve being provided for exhausting the secondary pilot line to thereby reset the timer valve. This allows the timer valve to be reset to a default position and a new time period commenced.

[0029] In a further example, the exhaust valve can be formed from a secondary timer valve adapted to selectively reset the timer valve after a second pre-determined time period. This could be used for example to provide a short time period such as 10 minutes before the timer valve is actuated. Upon actuation, the timer valve will cause the pressurised fluid supply to activate, thereby allowing users time to vacate the working area before the compressed airflow begins. Following this, the timer valve will reset after 2 hours, allowing wastage of compressed air to be avoided.

[0030] A further specific example of a fluid supply and associated control system is shown in Figure 2.

[0031] In this example, the fluid supply includes a feed line 210, which is coupled to equipment, allowing compressed air or another suitable fluid to be supplied thereto.

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-62018100278 02 Mar 2018 [0032] An angled seat valve 221 is provided in the feed line, allowing flow of air through the feed line to be controlled. A first pilot line portion 222.1 extends from the feed line upstream of the control valve 221 to a regulator 224. The regulator 224 is adapted to control the fluid pressure in downstream portions of the pilot line, as will be appreciated by persons skilled in the art. In one example, the regulator is a self-draining regulator 224, allowing water to be drained from the compressed air via a drain line 224.1.

[0033] An output of the regulator is typically attached via a T coupling 225 to a second pilot line portion 222.2, which extends to an input of the timer valve 223. The timer valve typically includes timer valve outputs, with one of these being coupled to a third pilot line portion 222.3, which extends to the control valve. The timer valve outputs can have different functions, depending on the valve configuration, so that for example, one valve output may supply compressed air, when the other does not, and with these exchanging function once the predetermined time has passed. In this way it will be appreciated that operation of the control valve to activate or deactivate the flow of fluid after the predetermined time can be controlled based on the timer valve output to which the third pilot line portion 222.3 is connected. The timer valve may also include an exhaust line 223.1 for exhausting excess compressed air.

[0034] The T coupling 225 is also connected to a secondary pilot line 226, which extends to an exhaust valve 227, which functions as a pilot line dump control, exhausting compressed air via an exhaust outlet 227.1. This resets the timer valve 223.

[0035] The above described arrangements therefore provide mechanisms to allow supply of compressed air or other pressurised fluids to be controlled, meaning that control systems can be provided that are able to meet safety requirements, including but not limited to coal mining regulatory requirements.

[0036] Throughout this specification and 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 group of integers or steps but not the exclusion of any other integer or group of integers.

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-72018100278 02 Mar 2018 [0037] Persons skilled in the art will appreciate that numerous variations and modifications will become apparent. All such variations and modifications which become apparent to persons skilled in the art, should be considered to fall within the spirit and scope that the invention broadly appearing before described.

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2018100278 02 Mar 2018

Claims (5)

1. THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

   1) A control system for controlling supply of pressurized fluid via a pressurized feed line, the control system including:

   a) a fluid operated control valve positioned in the feed line to selectively control flow of fluid through the feed line;

   b) a pilot line coupled to the feed line upstream of the control valve and extending to the fluid operated control valve; and,

   c) a timer valve provided in the pilot line, the timer valve being operating to selectively provide fluid to the control valve to thereby control operation of the control valve and thereby at least one of:

   i) activate supply of pressurized fluid via the pressurized feed line after a predetermined time period; and, ii) deactivate supply of pressurized fluid via the pressurized feed line after a predetermined time period.
2. 2) A control system according to claim 1, wherein the control system includes a regulator provided in the pilot line between the feed line and the timer valve to regulate a fluid pressure in the pilot line.
3. 3) A control system according to claim 1, wherein the timer valve is actuated after a predetermined time period.
4. 4) A control system according to claim 1, wherein the control system includes:

   a) a secondary pilot line extending from the pilot line to a timer valve reset input; and,

   b) an exhaust valve for exhausting the timer valve to thereby reset the timer valve.
5. 5) A control system according to claim 1, wherein the exhaust valve is a secondary timer valve adapted to selectively reset the timer valve after a second predetermined time period.

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