1. Field of the Invention
This invention relates to a system and method for delivering a breathable gas supply to underground mines in the event of an emergency that traps workers underground and/or contaminates the underground air with toxic gases.
2. Description of Related Art
Mining ventilation is a significant safety concern for underground workers. Poor ventilation of the mines causes exposure to harmful gases, heat and dust inside sub-surface mines. Various methods are known in the art for providing adequate ventilation, including dilution (ventilation), capture before entering the host air stream (methane drainage), or isolation (seals and stoppings). In the event of an underground explosion, however, the primary ventilation system can fail, exposing workers to potentially fatal concentrations of airborne contaminants.
At present, workers have few options in the aftermath of an explosion: attempt to escape or barricade themselves and await rescue. Although every underground worker's preferred option is to escape, fire or debris from the explosion or severe injury may prevent them from doing so. Life-sustaining supplies can be pre-positioned throughout the mine to provide continued sustenance to trapped workers, but at present there is no effective way to provide a dependable, continuous supply of breathable gas in the immediate aftermath of a blast. An underground explosion is also likely to damage any exposed ductwork in the passageway that might be relied on to transport breathable gas to trapped workers. In the time required to drill a borehole from the surface of the mine to the underground passageway, the concentration of carbon monoxide and other toxic gases may reach fatal levels. Accordingly, there exists a need for a system and method for delivering a continuous source of breathable gas that is accessible to underground workers at various locations within the mine and that can be activated immediately following an explosion.
The present invention includes a system for delivering a sustainable emergency supply of a breathable gas to a chamber in an underground mine including a passageway having a ceiling and a floor. The system includes a source of breathable gas located exterior to the chamber, a pipe system in fluid communication with the breathable gas source for transporting a supply of breathable gas to the chamber, and at least one regulator for controlling the rate at which the breathable gas is released from the pipe system. An exemplary breathable gas source includes, but is not limited to, a compressor located at ground level and exterior to the mine, and an exemplary breathable gas includes, but is not limited to, atmospheric air and oxygen-enriched air. The pipe system is buried below the surface of the mine floor to protect the pipes transporting a breathable gas against damage resulting from an explosion, collapse, or combination thereof, as well as any damage that might result from the use of underground excavating equipment. A suitable location of the regulator is in the chamber.
The present invention further includes a method of delivering sustenance to at least one person occupying a chamber in an underground mine. The method includes providing a source of breathable gas, transporting the breathable gas through a pipe system in fluid communication with the gas source, and controlling the rate at which the breathable gas is released from a regulator in the chamber.
Other features of the invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description, taken with the accompanying drawings, wherein like reference numerals represent like elements throughout.
For purposes of the description hereinafter, spatial or directional terms shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations, except where expressly specified to the contrary. It is also to be understood that the specific apparatus illustrated in the attached drawings, and described in the following specification, is simply an exemplary embodiment of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting, unless otherwise indicated.
With reference to
A breathable gas source 14 is located exterior to the chamber 20 and may be positioned above ground. One suitable breathable gas source is a compressor. A pipe system 16 is in fluid connection with the breathable gas source 14 and the chamber 20 and is buried beneath the surface of the mine floor 12b to protect the pipe system 16 from damage. Referring to
In one embodiment, the pipe system 16 comprises a main pipe 24 and at least one branch pipe 26. For example, main pipe 24 may have an internal diameter of about eight inches and branch pipes 26 may have internal diameters of about two inches. The pipe system 16 may include a plurality of branch pipes 26 extending into separate chambers 20. In this manner, pipe system 16 is installed and available for use at any time. Importantly, by burying pipe system 16 underneath the floor 12b and/or within the walls 12c of underground passageway 12, the pipe system 16 remains unaffected by forces associated with an explosion, roof failure, or the like.
The breathable gas source 14 is capable of producing sufficient gas flow to displace gases preexisting in chamber 20 (e.g., CO) and sustaining at least one person for an extended period of time. A vent may be provided in a surface of the chamber to allow gas to exit the chamber while breathable gas is provided through the pipe system 16. Alternatively, barrier 22 may allow venting therethrough. Branch pipe 26 extends beyond the barrier 22 to a position underneath the floor 12b or the surrounding rock walls of the chamber 20, where branch pipe 26 extends into the chamber 20. An exposed end 26a of branch pipe 26 may extend into chamber 20 through floor 12b, as shown, or through side walls of chamber 20. The walls, ceiling, and floor of chamber 20 may be exposed rock surface or an engineered structure (panels, blocks, etc.). Breathable gas released from exposed end 26a of branch pipe 26 purges the preexisting contaminating gases trapped behind the closeable barrier 22, thereby sustaining at least one person occupying the chamber 20.
The system of the present invention may be used during an emergency when underground personnel require a safe environment. Personnel entering a chamber 20 activate regulator 28 to begin flow of fresh breathable gas supply 18 and barrier 22 is closed or constructed. Any undesired gas preexisting in the chamber 20 or produced during respiration (e.g., CO2) may be expelled by the positive pressure of the gas supply 14 and exits the chamber 20, such as through the vent or gaps in the surrounding rock. Regulator 28 may be operated to control the rate at which the breathable gas 18 is released into chamber 20. With reference to
The invention has been described with reference to the desirable embodiments. Modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
This application claims the benefit of U.S. Provisional Application No. 61/286,073, filed Dec. 14, 2009, herein incorporated by reference.
Number | Date | Country | |
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61286073 | Dec 2009 | US |