BACKGROUND
Proper ventilation is important in coal mines. The mining of coal often produces toxic and/or combustible dust and gasses, for example, methane. It is desirable to remove these potentially harmful gasses and dust from an operating coal mine, especially from the face of the mine (the operations area of the mine) to enhance the safety of mine workers and to reduce the potential for accidents such as explosions. The ventilation of a coal mine often involves multiple air handling units, for example, fans and air ducts. Further, air blocking or redirecting mechanisms, for example, doors or air impermeable block bathers may be provided at various positions within the mine so that air is directed to where it is desired. It is often desirable to prevent uncontrolled passage of air into or out of a mine through entrances or exits of the mine because this uncontrolled passage of air may disrupt the desired flow of ventilation to the mine face (or operation area of the mine)
SUMMARY
In accordance with an aspect of the present disclosure there is provided a mine airlock. The mine airlock comprises a plurality of airlock doors. At least one of the airlock doors includes a frame including at least one door jamb and a lintel, a face leaf hingedly secured to the lintel, the face leaf having an upper section removably secured to a lower section, and a side leaf secured to the at least one door jamb. The face leaf forms a substantially airtight seal with the lintel and the side leaf in a closed position.
In some embodiments the at least one airlock door further comprises an actuator including a first portion secured to the frame and a second portion secured to the face leaf. The actuator is configured to displace the face leaf away from and toward the frame.
In some embodiments the actuator comprises one of a hydraulic piston and a pneumatic piston.
In some embodiments the side leaf is substantially triangular.
In some embodiments a portion of the face leaf engages a resilient material disposed on a front edge of the side leaf in a closed position.
In some embodiments the at least one airlock door includes a cover plate secured to a front surface of the face leaf and positioned to overlie a joint between the upper section and the lower section of the face leaf.
In some embodiments the at least one airlock door further comprises an air guard cap secured to the face leaf which partially overlies a side surface of the side leaf in a closed position.
In some embodiments the at least one airlock door further comprises a safety leg hingedly secured to a rear surface of the face leaf.
In some embodiments the at least one airlock door further comprises a substantially air impermeable barrier disposed between sides of the at least one airlock door and walls of a mine passageway.
In some embodiments the at least one airlock door further comprises a substantially air impermeable material coupled to the lintel and to a front portion of the face leaf and overlying a hinge coupling the face leaf to the lintel.
In accordance with another aspect of the present disclosure there is provided a airlock door for a mine. The airlock door comprises a frame including at least one door jamb configured to be secured to one of an upper and a lower wall of a mine passageway and a lintel, a face leaf hingedly secured to the lintel, the face leaf having an upper section removably secured to a lower section, and a side leaf secured to the at least one door jamb. The face leaf forms a substantially airtight seal with the lintel and the side leaf in a closed position.
In some embodiments the airlock door further comprises an actuator including a first portion secured to the frame and a second portion secured to the face leaf, the actuator configured to displace the face leaf away from and toward the frame.
In some embodiments the actuator comprises one of a hydraulic piston and a pneumatic piston.
In some embodiments the side leaf is substantially triangular.
In some embodiments a portion of the face leaf engages a resilient material disposed on a front edge of the side leaf in a closed position.
In some embodiments the airlock door further comprises a cover plate secured to a front surface of the face leaf and positioned to overlie a joint between the upper section and the lower section of the face leaf.
In some embodiments the airlock door further comprises an air guard cap secured to the face leaf which partially overlies a side surface of the side leaf in a closed position.
In some embodiments the airlock door further comprises a safety leg hingedly secured to a rear surface of the face leaf.
In some embodiments the airlock door further comprises a substantially air impermeable barrier disposed between sides of the airlock door and walls of the mine passageway.
In some embodiments the airlock door further comprises a substantially air impermeable material coupled to the lintel and to a front portion of the face leaf and overlying a hinge coupling the face leaf to the lintel.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:
FIG. 1A is a cross-sectional schematic diagram of an arrangement of an embodiment of an airlock system in a mine passageway with airlock doors closed;
FIG. 1B is a cross-sectional schematic diagram of an arrangement of the embodiment of the airlock system in the mine passageway of FIG. 1A with airlock doors opened;
FIG. 2A is an isometric view of an embodiment of an airlock door in a closed position;
FIG. 2B is an isometric view of the airlock door of FIG. 2A in an open position;
FIG. 3 is an elevational view of an embodiment of an airlock door installed in a mine passageway;
FIG. 4 is an elevational view of the rear of an embodiment of a face leaf of an airlock door;
FIG. 5 is an elevational view of the rear of an embodiment of a face leaf of another airlock door;
FIG. 6A illustrates an embodiment of angle irons which are used to secure the upper and lower sections of the face leaf of FIG. 5 together;
FIG. 6B illustrates the arrangement of the angle irons of FIG. 6A on the face leaf of FIG. 5;
FIG. 7 is an elevational view of an embodiment of a frame of an airlock door;
FIG. 8 is a cross sectional view of an embodiment of a face leaf of an airlock door secured to a frame;
FIG. 9A is an elevational view from the front of an embodiment of a side leaf of an airlock door connected to a door jamb of a frame;
FIG. 9B is an elevational view from the side of the side leaf and door jamb of FIG. 9A;
FIG. 9C is a plan view from above of the side leaf and door jamb of FIG. 9A;
FIG. 10A is an elevational view from the side of an embodiment of a trunion block;
FIG. 10B is an elevational view from the front of the trunion block of FIG. 10A;
FIG. 10C is a plan view from the top of the trunion block of FIG. 10A;
FIG. 11A is an elevational view from the side of an embodiment of a door jack ear;
FIG. 11B is an elevational view from the front of the door jack ear of FIG. 11A;
FIG. 11C is a plan view from above of the door jack ear of FIG. 11A;
FIG. 12A is an elevational view from the side of an embodiment of a base plate secured to the door jack ear of FIG. 11A;
FIG. 12B is an elevational view from the rear of the base plate and door jack ear of FIG. 12A;
FIG. 12C is a plan view from above of the base plate and door jack ear of FIG. 12A;
FIG. 13A is an exploded view of an embodiment of a safety leg;
FIG. 13B is an isometric view from the side of a foot plate of the safety leg of FIG. 13A;
FIG. 13C is a plan view from above of the foot plate of the safety leg of FIG. 13A;
FIG. 13D is an isometric view from the rear of the foot plate of the safety leg of FIG. 13A; and
FIG. 14 illustrates an embodiment of air guard cap secured to a face leaf of an airlock door.
DETAILED DESCRIPTION
Aspects and embodiments disclosed herein are not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. Aspects and embodiments disclosed herein are capable of other embodiments and of being practiced or of being carried out in various ways.
Disclosed herein are aspects and embodiments of an airlock system for a mine, for example, a coal mine. Prior airlock systems have employed various types of doors to facilitate blocking the flow of air through the systems. These doors have included, for example, dual leaf swinging doors, roll-up doors, and sectional doors. The doors in prior airlock system have typically not provided a desired degree of impermeability to air and/or a desired degree of mechanical strength. Further, some previously known mine airlock door systems have required more overhead room to accommodate the doors than desired. Various aspects and embodiments of airlock door systems disclosed herein exhibit superior air impermeability and mechanical strength as compared to prior systems.
An embodiment of an airlock system is illustrated in FIG. 1A and FIG. 1B. The airlock system 10 includes a pair of airlock doors 100 disposed apart from each other in a mine passageway 110 and forming an airlock space 120 therebetween. FIG. 1A illustrates the airlock doors 100 in closed positions and FIG. 1B illustrates the airlock doors in open positions. In some embodiments, the airlock system 10 includes two complete door systems. The mine passageway includes a fresh air or external side 130 and a mine or internal side 140. An external airlock door 100 may border the external side 130 and an internal airlock door 100 may border the mine side 140. The airlock doors 100 may be substantially similar and may include generally rectangular solid front or face leafs 150 and generally triangular solid side leafs 160. In some embodiments, the airlock doors may be arranged such that the face leafs 150 open toward the external side 130. The side of the face leaf 150 of the external door 100 facing the external side 130 of the mine passageway and the side of the face leaf 150 of the internal door 100 facing the mine side 140 of the mine passageway will be referred to herein as the front side of the face leafs 150. Side air guard caps 170 may be secured to the face leafs and may include portions disposed at, for example, at an angle normal to the plane of the face leafs 150. The side air guard caps 170 may partially overlap the side leafs 160 when the doors are in a closed position. An actuator, for example, a hydraulic or pneumatic piston 180 may be provided to open and close the doors 100. The face leaf 150, side leafs 160, and/or side air guard caps 170 may be constructed of a metal, for example steel, and/or an engineering plastic or composite material. Embodiments of the doors 100 are not limited to any particular materials of construction.
Control panels 190, which may include a three button control station, may be provided so that an operator may open, close, or stop the doors. In operation, an operator would open a first of the doors 100, pass through the first of the doors 100, close the first of the doors 100, open a second of the doors 100, pass through the second of the doors 100, and close the second of the doors 100. The control panels 190 may be coupled to a controller (not shown) including an interlock which prevents the opening of both doors 100 at the same time. An embodiment of an airlock door 100 is illustrated in FIGS. 2A and 2B in a closed and an open state, respectively. In FIG. 2B, safety legs 440, described in further detail below, are in an extended state to facilitate maintaining the door in an open position.
An embodiment of an airlock door 100 installed within walls 200 of a mine passageway is illustrated schematically in FIG. 3. The door 100 may be mounted within the walls of the mine passageway on a door frame 300 including a pair of spaced apart generally vertical door jambs 310. The door jambs 310 may comprise metallic columns. The door jambs 310 may be secured to the roof and floor of the mine passageway by, for example, plates 320 welded or otherwise secured to the upper and lower ends of the door jambs 310, and bolted or otherwise secured to the upper and lower walls of the mine passageway. The door frame 300 also includes a lintel 330 secured to the door jambs 310 and extending therebetween. In some embodiments, the lintel 330 may be mounted within about six inches (15.2 cm) of the roof of the mine passageway. The face leaf 150 may be hingedly secured to the lintel 330 and may open and close by rotating about a hinge 340. In some embodiments, the face leaf may be provided with a strip 350 of a resilient material, for example, a sheet of natural rubber or a strip of foam rubber on its lower edge to facilitate forming an air impermeable seal with the floor of the mine passageway when the door is closed. A substantially air impermeable barrier 360 may be provided between the door frame 300 and the walls of the mine passageway. The barrier may include, for example, metal or plastic sheeting or wood paneling, or in instances where the door frame 300 closely approaches a wall of the mine passageway, a plastic or rubber foam. A man door 370 may be provided in the barrier 360, or in some embodiments in the face leaf 150 or a side leaf 160 of the door 100 to provide emergency access through the mine passageway.
An embodiment of a face leaf 150 viewed from the rear side is illustrated in FIG. 4. The face leaf 150 includes a face leaf frame 410. The face leaf frame 410 may be formed from tubing, for example, metal or plastic tubing. The tubing may be cylindrical or may have a square or triangular cross section or a cross section of a different shape. The tubing is, in some embodiments, steel tubing with a diameter of about one inch (2.54 cm). A sheet of material 420 may be disposed on the frame 410. The sheet of material may include, for example, a metal sheet and/or a sheet of plastic or a composite material, for example, fiberglass. In some embodiments the sheet of material 420 is a ⅛ inch (32 mm) thick sheet of steel. The sheet of material 420 may be secured to the frame 410 by welding and/or by a plurality of fasteners, for example, screws or nuts and bolts.
A pair of jack ears 430 may be disposed within jack ear bases 1200 on the rear side of the face leaf frame 410 and secured thereto by welding and/or by a plurality of fasteners, for example, screws or nuts and bolts. The jack ears 430 may include an aperture to provide for securing an end of a piston 180, for example, a pneumatic or hydraulic piston to the face leaf 150 to provide for opening or closing of the door 100 with the piston 180.
A pair of safety legs 440 may also be secured to a portion of the face leaf frame 410. The safety legs 440 may be secured to the face leaf frame 410 by a hinge 450. The safety legs 440 may be used to support the face leaf 150 in an open position during, for example, maintenance activities. The safety legs 440 may be secured against the face leaf frame 410 by, for example, a pin extending through an aperture in the safety legs and in a portion of the face leaf frame at, for example, the positions indicated at 460.
In some embodiments, as illustrated in FIG. 5, the face leaf 150 may be formed from an upper section 150A and a lower section 150B. The upper and lower sections 150A and 150B may be releasably joined by a set of angle irons 470. The angle irons 470 may be secured to the frames 410 of the upper and lower sections 150A and 150B by welding and/or by a plurality of fasteners, for example, screws or nuts and bolts and to one another by a plurality of fasteners, for example, screws or nuts and bolts. The provision of the face leaf 150 in two sections may facilitate transport of the face leaf to an installation site. The provision of the face leaf 150 in two sections may also provide for only a single section of the face leaf 150 to be replaced when damaged. For example, if the lower section 150B were to be damaged by, for example, impact by a mining cart, it could be removed from the upper section 150A and replaced with a new lower section 150B. Such a repair may be less costly than replacing the entire face leaf 150.
Details of an embodiment of the angle irons 470 are provided in FIGS. 6A and 6B. As shown in FIG. 6A, the angle irons may be formed from an L-shaped strip of a material, for example, metal (e.g., steel) or plastic. A plurality of apertures 475 (a single row as illustrated in FIG. 6A or multiple rows as illustrated in FIG. 6B) may be provided accommodate fasteners to releasably secure the angle irons 470 to one another. In some embodiments where an upper portion 150A and a lower portion 150B of the face leaf 150 are joined by the angle irons 470, a cover sheet 480 formed of a metal or plastic material may be secured to the front side of the upper portion 150A or lower portion 150B to cover a joint between the two when joined and facilitate reducing the potential for air to pass through the joint.
Details of the door frame 300 are illustrated in FIG. 7. The door frame 300 includes a pair of spaced apart generally vertical door jambs 310. The door jambs 310 may comprise metallic columns, for example, steel I-beams. In some embodiments, the door jambs 310 may be formed from steel I-beams which are about four inches (10.2 cm) on a side. The door jambs 310 may include plates 320 welded or otherwise secured to the upper and lower ends of the door jambs 310, and bolted or otherwise secured to the roof and floor of the mine passageway. The door frame 300 includes a lintel 330 secured to the door jambs 310 and extending therebetween. In some embodiments, the lintel 330 is formed of a steel tube having a substantially square cross section about four inches (10.2 cm) on a side. A trunion block 380 may be secured, for example, by welding or with fasteners such as screws or nuts and bolts, to internal sides of each of the door jambs 310. The trunion blocks 380 may be configured to secure a portion of a piston 180, for example, a body of a piston 180 to each of the door jambs 310. Another portion of the pistons 180, for example, shafts of the pistons 180 may be secured to the jack ears 430 of the face leaf 150. Extension or contraction of the pistons 180 may drive the face leaf 150 away from and toward the door frame 300, respectively.
Details of the connection between the face leaf 150 and the door frame 300 are illustrated in FIG. 8. The face leaf 150 is secured to the lintel 330 with a hinge 340 which provides for the face leaf 150 to rotate relative to the door frame 300. When in a partially or fully open position the jack ears 430 on the face leaf 150 are displaced from the trunion blocks 380 on the door jambs 310 by an expanded piston 180 (not shown in FIG. 8). In some embodiments a sheet 390 of substantially air impermeable material may be secured to an upper portion of the lintel 330 and to the front of the face leaf 150 below the hinge 340. The sheet 390 may be formed of, for example, rubber. The sheet 390 may facilitate limiting or eliminating air passage through the hinge 340.
Details of the side leafs 160 and their connection to the door jambs 310 are illustrated in FIGS. 9A, 9B, and 9C. As illustrated in FIGS. 9A-9C, a substantially L-shaped angle iron 910 is secured to front sides of the door jambs 310 and to an internal side of the side leafs 160. The angle iron 910 may be secured to the door jambs 310 and/or side leafs by welding or by fasteners, for example, screws or nuts and bolts or other fasteners known in the art. The side leafs 160 are provided with a strip of resilient material 920, for example, foam rubber or a sheet of natural rubber on their front edges. The resilient material 920 may facilitate forming an air tight seal between the side leafs 160 and the face leaf 150 when closed.
FIGS. 10A, 10B, and 10C illustrate details of the trunion blocks 380. The trunion blocks may in some embodiments be formed of a substantially U shaped member. The trunion blocks 380 may include apertures 1010, for example circular apertures with diameters of about 1.25 inches (3.2 cm) on upper portions of the “U”. These apertures 1010 may be utilized to secure a first portion of an actuator, for example, a body of a piston 180 to the door frame 300. The trunion blocks 380 may be formed from two L-shaped sections 380A and 380B joined together by welding or by one or more bolts 1020. Each trunion block 380 is secured to a door jamb 310 of the door frame 300 by, for example, welding or with one or more fasteners, for example, screws or nuts and bolts or other fasteners known in the art.
The door jack ears 430 are utilized to connect a second portion of an actuator, for example, a piston 180 to the face leaf 150. Details of an embodiment of a jack ear are illustrated in FIGS. 11A, 11B, and 11C. Each jack ear 430 may be formed of a substantially flat plate of material, for example, steel having a thickness of, for example, about 0.5 inches (1.3 cm). The jack ears 430 may include a base portion 430A which may be substantially rectangular and have a width of, for example, about 5.5 inches (14 cm) and a height of, for example, about 1.5 inches (3.8 cm). The jack ears may also include an upper portion 430B formed integral with the lower portion. The upper portion 430B may be substantially semi-circular with a radius of curvature of about one inch (2.54 cm) and a height of about 1.5 inches (3.8 cm). The upper portion 430B may include an aperture 1110 to which may be secured the second portion of the actuator.
The door jack ears 430 may be coupled to base plates 1200 which are in turn coupled to the rear of the face leaf 150. The door jack ears 430 may be coupled to base plates 1200 by, for example welding or with one or more fasteners, for example, screws or nuts and bolts or other fasteners known in the art. As illustrated in FIGS. 12A, 12B, and 12C the base plates 1200 may be formed from a substantially U-shaped piece of material, for example, steel having a length of, for example, about 31 inches (78.7 cm) and a width and height sufficient to retain the door jack ears 430 with no gap between the inner surfaces of the “U” of the base plates and the edges of the base of the door jack ears 430. In some embodiments, the base plates 1200 are formed from two adjoined L-shaped angle irons 1200A, 1200B. The door jack ears 430 may be secured in the base plates 1200 proximate a first end of the base plates 1200, for example, about two inches (5.1 cm) from first ends of the base plate.
Details of the safety legs 440 are illustrated in FIGS. 13A and 13B. The safety legs each include an inner member 440A and an outer member 440B. The inner and outer members 440A and 440B may be sufficiently sized and shaped to provide for the inner member 440A to be inserted in a sliding relationship within the outer member 440B with sufficiently little clearance between the outer surfaces of the inner member 440A and the inner surfaces of the outer member 440B other than to provide sufficient clearance for the inner member 440A to slide into and out from the outer member 440B. The inner member 440A may be secured in place within the outer member 440B by, for example, a pin inserted through an aperture 1310 in the outer member 440B and a corresponding aperture 1320 in the inner member 440A. Either or both of the outer member 440B and inner member 440A may have multiple apertures 1310, 1320 to provide for the inner member 440A to be disposed at different degrees of extension from the lower end 1330 of the outer member. The outer member may further include a hinge aperture 1340 which may be utilized to hingedly secure the safety leg to the rear side of the face leaf 150. In some embodiments each of the inner and outer members 440A, 440B comprise tubes, for example, cylindrical tubes or tubes having a square or other cross section. The inner member 440A may have a diameter of, for example about one inch (2.54 cm) and the outer member may have an outer diameter of, for example, about 1.5 inches (3.8 cm).
A foot plate 400C may be secured to a lower end 1350 of the inner member 440A. The foot plate may be formed from a substantially L-shaped plate of material, for example, steel. The foot plate 400C is illustrated in a side view, top down view and front view in FIGS. 13B, 13C, and 13D, respectively.
Details of the air guard caps 170 secured to the face leaf 150 are illustrated in FIG. 14. The air guard caps 170 are secured to opposing sides ends of the face leaf 150 and may extend substantially along the side edges of the face leaf 150 from an upper edge to a lower edge of the face leaf 150. The air guard caps 170 may be formed from an L-shaped angle iron. Each leg of the L-shaped angle iron may have a length of, for example, about three inches (7.6 cm). A spacing of, for example, about 1.75 inches (4.4 cm) may be provided between a side edge 155 of the face leaf 150 and an internal surface 175 of an outer leg 170A of the air guard caps 170. An internal surface 178 of a front leg 170B of the air guard caps 170 may be secured to the sheet of material 420 and/or the frame 410 of the face leaf by, for example, welding or with one or more fasteners, for example, screws or nuts and bolts or other fasteners known in the art. When the door 100 is closed, the strip of resilient material 920 disposed on the side leafs 160 may contact the internal surface 178 of the front leg 170B of the air guard caps 170 and form a substantially airtight seal between the face leaf 150 and the side leafs 160.
In accordance with various embodiments of the present disclosure, there is provided a method of facilitating the control of air through a mine passageway. The method comprises installing at least one airlock door as described herein in the mine passageway. In another embodiment, the method comprises removing an old airlock door from a mine passageway and replacing the old airlock door with at least one airlock door as described herein in the mine passageway. Installing or replacing an airlock door may include transporting an airlock door as described herein to an installation site with the face leaf divided into separate upper and lower portions and joining the upper and lower portions at the installation site to form the face leaf. In another embodiment, the method comprises performing a repair of a mine airlock door as described herein, the repair including replacing one of an upper and lower section of a face leaf of an airlock door.
The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, the term “plurality” refers to two or more items or components. The terms “comprising,” “including,” “carrying,” “having,” “containing,” and “involving,” whether in the written description or the claims and the like, are open-ended terms, i.e., to mean “including but not limited to.” Thus, the use of such terms is meant to encompass the items listed thereafter, and equivalents thereof, as well as additional items. Only the transitional phrases “consisting of” and “consisting essentially of,” are closed or semi-closed transitional phrases, respectively, with respect to the claims. Use of ordinal terms such as “first,” “second,” “third,” and the like in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.
Having thus described several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the disclosure. Accordingly, the foregoing description and drawings are by way of example only.
Patent Application
20140273791
