AU2014202600A1

AU2014202600A1 - Change over station and method

Info

Publication number: AU2014202600A1
Application number: AU2014202600A
Authority: AU
Inventors: David Emerson Maust; Kyle R. Murray; John J. Reinmann Jr.
Original assignee: Strata Products Worldwide LLC
Current assignee: Strata Products Worldwide LLC
Priority date: 2013-05-24
Filing date: 2014-05-13
Publication date: 2014-12-11
Anticipated expiration: 2034-05-13
Also published as: MX2014005792A; CN104314611A; CA2852095A1; GB201409185D0; PL408312A1; AU2014202600B2; ZA201403668B; RU2014120483A; US20140349562A1; CL2014001319A1; GB2516544A; CA2852095C

Abstract

A change over station (COS) for persons in a hazardous environment includes a steel housing having only a single entrance door, a chamber, and an air lock portion. The COS includes a first elongate seat disposed in the chamber and a plurality of compressed air cylinders disposed in the seat. The COS includes plumbing connected to the air cylinders formed of gas lines and valves and an exhaust muffler including first, second and third air paths that provide air into the chamber. The third air path is door activated when the door is opened by a door activated switch. The COS includes a storage portion disposed in the housing having supplies, including water and SCSRs or SCBAs. A method for providing a protected environment to miners from a mine environment in a mine. 53832021 (GHMatters) P97023.AU 13/05/14 CDo (0c c-4I Co c---4

Description

1 TITLE OF THE INVENTION Change Over Station and Method FIELD OF THE INVENTION [0001] The present invention is related to a change over station in which miners enter to escape the mine environment and access supplies. (As used herein, references to the "present invention" or "invention" relate to exemplary embodiments and not necessarily to every embodiment encompassed by the appended claims.) More specifically, the present invention is related to a change over station in which miners enter to escape the mine environment and access supplies while in a chamber of a steel housing that is maintained with positive pressure from pressurized air to keep the mine environment out of the chamber. BACKGROUND OF THE INVENTION [0002] This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the present invention. The following discussion is intended to provide information to facilitate a better understanding of the present invention. Accordingly, it should be understood that statements in the following discussion are to be read in this light, and not as admissions of prior art. [0003] Miners carry on themselves SCSRs/SCBAs that have a minimal amount of oxygen. In case of an emergency, miners will put these SCSRs/SCBAs on to breathe fresh oxygen. In case miners are far from the mine face, they have stations that store SCSR's/SCBA's. These stations do not allow for the miners to escape the mine environment to change their used SCSRs/SCBAs. There is a need to provide protection to miners from the mine environment while they change their SCSRs/SCBAs, and possibly regroup to figure out a way to save themselves, whether it be to identify a path to escape from the mine or to access and deploy a refuge shelter in the mine if there is no viable path to escape the mine. 53832021 (GHMatters) P97023.AU 13/05/14 2 BRIEF SUMMARY OF THE INVENTION [0004] The main purpose of the COS is the storage of SCSR's and/or SCBA's. Also, to provide miners a clean environment to change out their SCSR's/SCBA's. This is NOT intended to be a REFUGE CHAMBER and is not a refuge chamber as defined by 30 Code of Federal Regulations Part 7 (30CFR Part 7). [0005] The present invention pertains to a change over station (COS) for persons in a hazardous environment. The COS comprises a steel housing having only a single door, a chamber, and an air lock portion. The door opening to the air lock portion. The air lock portion connected to the chamber. The COS comprises a first elongate seat disposed in the chamber. The COS comprises a plurality of compressed gas cylinders, such as air, cylinders, disposed in the seat. The COS comprises plumbing connected to the air cylinders formed of gas lines, such as air lines 28, and valves and an exhaust muffler, including a first gas, such as air path through the lines that provides a continuous flow of air into the chamber through the muffler at a rate of greater than 4 cfm when the plumbing is in an on state, a second gas, such as air, path through the lines that provides a continuous flow of air into the chamber through the muffler at a rate of less than 1.5 cfm when the plumbing is in a standby state, and a third gas, such as air, path through the lines which is door activated when the door is opened by a door activated switch which provides additional air flow as long as the door is open at a rate of greater than 4 cfm into the chamber through the . The COS comprises a valve control panel through which the plumbing extends and which is disposed on the outside of the housing which controls whether the plumbing is in the on state or the standby s. The COS comprises a storage portion 44 disposed in the housing having supplies, including water and SCSRs or SCBAs. [0006] The present invention pertains to a method for providing a protected environment to miners from a mine environment in a mine. The method comprises the steps of opening a primary valve disposed in a control panel located on the outside of a steel housing of a change over station (COS) to an on state which causes compressed air from 53832021 (GHMatters) P97023.AU 13/05/14 3 compressed air cylinders inside the housing to flow through a first flow path of plumbing in the steel housing into the chamber of the housing and create positive pressure in the chamber relative to the mine environment. There is the step of opening a door of the housing which activates a door activated switch that causes compressed air from the compressed air cylinders to flow through a third flow path of the plumbing into the chamber of the housing and add to the flow through the first flow path of compressed air into the chamber to increase the positive pressure in the chamber and to direct air flow out of the chamber and through the open door. There is the step of miners entering the chamber through the door, the miners taking SCSRs or SCBAs from a storage portion 44 in the housing and the miners using the SCSRs or SCBAs. There is the step of closing the door of the housing which deactivates the door activated switch stopping compressed air flow through the third flow path. There is the step of turning the primary valve to a standby state which causes the compressed air from the compressed air cylinders to flow through a second flow path of the plumbing into the chamber and a flow rate that is less than the rate of flow of compressed air through the first flow path. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING [0007] In the accompanying drawings, the preferred embodiment of the invention and preferred methods of practicing the invention are illustrated in which: [0008] Figure 1 is a plumbing schematic of a first embodiment of the present invention. [0009] Figure 2 is a second schematic of the plumbing of the present invention. [0010] Figures 3a - 3c show plan, side and end views of the air supply control panel of a second embodiment of the present invention. [0011] Figures 4-8 are various views of the change over station of the present invention. 53832021 (GHMatters) P97023.AU 13/05/14 4 [0012] Figure 9 shows a portion of the door, door frame, and door activated switch. DETAILED DESCRIPTION OF THE INVENTION [0013] Referring now to the drawings wherein like reference numerals refer to similar or identical parts throughout the several views, and more specifically to figure 5 thereof, there is shown a change over station (COS) 10 for persons in a hazardous environment. The COS 10 comprises a steel housing 12 having only a single door 14, a chamber 16, and an air lock portion 20. The door 14 opening to the air lock portion 20. The air lock portion 20 connected to the chamber 16. The COS 10 comprises a first elongate seat 24 disposed in the chamber 16. The COS 10 comprises a plurality of compressed air cylinders 22 disposed in the seat, as shown in figure 7. The COS 10 comprises plumbing 26, as shown in figure 1, connected to the air cylinders 22 formed of air lines 28 and valves 30 and an exhaust muffler 32. The plumbing 26 includes a first air path 34 through the lines that provides a continuous flow or air into the chamber 16 through the muffler 32 at a rate of greater than 4 cfm when the plumbing 26 is in an on state, a second air path 36 through the lines that provides a continuous flow of air into the chamber 16 through the muffler 32 at a rate of less than 1.5 cfm when the plumbing 26 is in a standby state, and a third air path 38 through the lines which is door activated when the door 14 is opened by a door activated switch 40 which provides additional air flow as long as the door 14 is open at a rate of greater than 4 cfm into the chamber 16 through the muffler 32. The COS 10 comprises a valve control panel 42, as shown in figure 3a, through which the plumbing 26 extends and which is disposed on the outside of the housing 12 which controls whether the plumbing 26 is in the on state or the standby state. The COS 10 comprises a storage portion 44 disposed in the housing 12 having supplies, including water and SCSRs or SCBAs 18. [0014] The plumbing 26 may include a primary valve 46 that controls whether air from the air cylinders 22 follows the first path or the second path. The primary valve 46 may be a 3 way valve 48, Off, On, and Standby: 53832021 (GHMatters) P97023.AU 13/05/14 5 [0015] a. Off - off [0016] b. On- chamber is ready for entry. [0017] c. Standby-chamber is activated with a trickle purge to keep the chamber clear of harmful gas after a first entry until a subsequent group arrives at the COS 10. [0018] The plumbing 26 through the first path and the second path may create positive pressure to keep contaminants out when the door 14 is open. The door activated switch 40 at the door 14 may activate a secondary valve 50, such as a door activated valve, of the plumbing 26 that increases air flow rate into the chamber 16 and blows air out the open door 14. The chamber 16 may have a net height of 60" and the housing 12 has a flat top 52 to maximize interior head room. The seat height may be about 16" to allow for a 6' person to sit upright in the chamber 16. [0019] The housing 12 may be approximately 12' long and narrow enough that it fits in a shipping container; 3 units in a 40' container. The COS 10 may handle 3 sequenced 10 man change over for a total of 10 men. The COS 10 may include a second elongate seat 54, as shown in figure 4, and wherein each seat provides 24"of space per man, and the seats provide air cylinder storage for up to 8 cylinders 22 is available. The storage portion 44 may serve as storage for 30 SCSRs 18 as well as 90 quarts of water. The plumbing 26 may include an orifice 56 and compressed air flow control 58 would be facilitated via the orifice 56. [0020] The space under the seats may allow for up to 8 cylinders 22 or a maximum of 4 hours in the ON mode, the standby mode substantially extends the reserve time by only releasing a trickle flow to maintain a slight positive pressure. The storage portion 44 of the water and SCSRs 18 are left and right just inside the door 14 for easy access. The COS 10 may include hanging plastic curtain strips 60 to help isolate the COS 10 atmosphere from the mine. The control panel may be recessed to prevent damage and may be provided with a tamper evident seal 62. 53832021 (GHMatters) P97023.AU 13/05/14 6 [0021] The present invention pertains to a method for providing a protected environment to miners from a mine environment in a mine. The method comprises the steps of opening a primary valve 46 disposed in a control panel 42 located on the outside of a steel housing 12 of a change over station (COS) 10 to an on state which causes compressed air from compressed air cylinders 22 inside the housing 12 to flow through a first flow path of plumbing 26 in the steel housing 12 into the chamber 16 of the housing 12 and create positive pressure in the chamber 16 relative to the mine environment. There is the step of opening a door 14 of the housing 12 which activates a door activated switch 40 that causes compressed air from the compressed air cylinders 22 to flow through a third flow path of the plumbing 26 into the chamber 16 of the housing 12 and add to the flow through the first flow path of compressed air into the chamber 16 to increase the positive pressure in the chamber 16 and to direct air flow out of the chamber 16 and through the open door 14. There is the step of miners entering the chamber 16 through the door 14, the miners taking SCSRs or SCBAs 18 from a storage portion 44 in the housing 12 and the miners using the SCSRs or SCBAs 18. There is the step of closing the door 14 of the housing 12 which deactivates the door activated switch 40 stopping compressed air flow through the third air path 38. There is the step of turning the primary valve 46 to a standby state which causes the compressed air from the compressed air cylinders 22 to flow through a second air path 36 of the plumbing 26 into the chamber 16 and a flow rate that is less than the rate of flow of compressed air through the first air path 34. [0022] There may be the step of the miners communicating from inside the chamber 16 with a location outside of the chamber 16. The miners may utilize communication devices they typically carry on them with the Commtrac system available from Strata Products Worldwide, and/or the Through the Earth Communication System also available from Strata Products Worldwide and described in US Patent Application 13/743,947, incorporated by reference herein. There may be the steps of the miners leaving the COS 10 and going to a refuge shelter and entering the refuge shelter. 53832021 (GHMatters) P97023.AU 13/05/14 7 [0023] In the operation of the invention, the change over station (COS) 10 provides miners an escape from the mine environment, which will allow the miners to safely change their used SCSRs/SCBAs 18 to new ones and have time to possibly regroup and plan a response to the emergency in a relatively safe environment out of the mine environment. The change over station 10 is a walk in steel chamber 16 that will have the capacity to store at least 30 SCSRs 18 or 30 SCBSs 18. The change over station 10 will also have the capability to store up to 90 quarts of water for the miners to re-hydrate themselves. [0024] The change over station 10 has the capability to handle 3 sequenced 10 men change overs for a total of 30 people. To create a clean environment, compressed air will be released inside the chamber 16 of the COS, which will create a positive pressure inside the chamber 16 and allow breathable air inside the chamber 16. According to calculations 1-4.5K bottle of compressed air will allow 10 men to exist an hour in the chamber 16. This will be increased to two cylinders 22 as a safety factor. The change over station 10 has the capacity to store 8-4.5K compressed air cylinders 22, to make the overall run time of the chamber 16 when activated last approximately 4 hours. This is believed to be more than enough time for the miners to resupply themselves, given the emergency circumstances, and make a decision to try to escape the mine or go to and access and deploy and enter a refuge shelter that provides long term life support, typically at least 96 hours. An example of a refuge shelter is that sold by Strata Products Worldwide, LLC identified as the Fresh Air Bay; see U.S. patent application 13/460252, incorporated by reference herein. [0025] Figures 4-8 show different views of the change over station 10 with the roof removed for better depiction. Figure 5 shows a front perspective view of the change over station 10 with the single door 14 shut. The door 14 opens outward from the steel chamber 16. Figures 4 and 6 show a front perspective view of the change over station 10 with the door 14 open. Figure 7 shows an overhead view of the change over station 10. The steel housing 12 is of a fixed size and is comprised of four walls, the base from which the four walls extend and a roof. The bench seats are on either side of the change over station 10. A portion of the top of 53832021 (GHMatters) P97023.AU 13/05/14 8 the bench is cut away on each side to reveal the pressurized tanks stored within the benches. Figure 8 shows a perspective view of the change over station 10 with the roof 63 in place. [0026] In the front of the change over station 10, adjacent the door 14 is the air lock portion 20 and also shelving 66 and storage areas 44 to hold the various supplies mentioned above. Figure 6 shows a left perspective view of the change over station 10 with the door 14 open and showing the shelving 66 and storage areas 44 in the front of the change over station 10. In the upper front right corner looking from the outside toward the front door 14 is the pressure relief valve 92. The air lock 20 is separated from the main part of the chamber 16 where the benches are located by plastic strips 60 that hang from the ceiling which act to contain flow of the mine environment into the change over station 10 when the door 14 is open. [0027] The structure of the change over station 10 is built out of steel tubing and sheet metal having a rectangular shape with the walls, floor and roof being rectangular shaped plates that are welded together. The overall dimensions of the structure are 144 in x 80 in x 60 in (LxWxH). The structure of the change over station 10 is built on the same base as the ERC sold by Strata Safety Products, the difference is the height of the COS being at a maximum of 5 ft. The height is to fit inside coal mines. There are benches inside of the chamber 16 for the miners to sit. The benches are a height that will allow a 6ft tall person to sit comfortably inside the chamber 16. [0028] In regard to the plumbing 26 and airflow, reference is made to figure 1. In one embodiment, each of 2 - 8 4. 5k compressed air cylinders 22 are connected in parallel through each cylinder's Monet valve 64 to a pressurized gas line. The gas line carrying the compressed air from the air cylinders 22 connects to a system valve 68. The system valve 68 controls the airflow through the gas line from the air cylinders 22 in total, either on or off. The system valve 68 is off during construction, but once construction is complete and the air cylinders 22 are connected to the gas line and the change over station 10 is ready for operation and to be delivered to a mine, the system valve 68 is turned on and pressurized gas is allowed to flow through the system valve 68. This is an always on system. A bottle pressure gauge is 53832021 (GHMatters) P97023.AU 13/05/14 9 connected to the line between the cylinders 22 and the system valve 68 for verification purposes each working shift. [0029] The gas line extends from the system valve 68, a Parker Veriflo HCV Valve with HP Gauge, to a step down valve 70, a Parker Veriflo Two Stage Pressure Regulator IR 6004 Outlet Range 10-250 PSIG, which takes the 4.5k PSI pressure in the line down to a workable pressure of about 100 PSI for downstream valves 30. The gas line extends from the step down valve 70 where it splits and extends to a door activated switch 40, such as a Parker Veriflo Door Activated 2 Position 3 Way Directional Valve P/N 47000074, and door activated valve, such as a Parker Veriflo NV17 AOP Valve, and the primary valve 46, such as a three way valve 48 or a position valve 48, Parker Veriflo NV17 Indicator Valve, which can either be off, on or in standby. [0030] The position valve 48 is maintained in an off position until miners need to use the change over station 10. In the off position, the position valve 48 prevents any flow of pressurized air through it. When miners need to use the change over station 10, they cause the position valve 48 to be turned to the on position. The position valve 48 is controlled from the outside of the change over station 10, before the miners enter the change over station 10. In the on position, flow of pressurized air flows through the position valve 48 and a 6.48 CFM orifice 56 and out into the chamber of the change over station 10 through the gas line that extends to a muffler 32 exhaust, such as a Parker Veriflo Muffler P/N 47000075, located in the rear of the chamber. By turning the position of the position valve 48 to on before the miners enter the chamber, positive pressure is created to limit or prevent the gas from the mine environment to enter the change over station 10. When miners vacate the chamber, they turn the position valve 48 to the standby position which allows a continuous flow of air to flow through the position valve 48 and through a .6 CFM orifice 56 through the gas line to the muffler 32 exhaust. In the standby position, air continues to enter the chamber but at a much reduced rate, waiting for any miners that might need it at a subsequent time to enter the chamber with positive pressure still maintained, but at a low enough rate to extend the duration of the viability of the change over station 10. 53832021 (GHMatters) P97023.AU 13/05/14 10 [0031] From the step down valve 70, the gas line also extends to a door activated valve through a door activated switch 40. The door activated valve allows pressurized air to merge with the air from the position valve 48 and pass into the chamber through the muffler 32 exhaust. When the door activated switch 40 is open, the pressurized gas passes through the switch 40 and through the door activated valve to a 6.48 CFM orifice 56 in the gas line extending from the door activated valve to the muffler 32 exhaust. The door activated switch 40 is just that; whenever the door 14 is open any amount, the door activated switch 40 is open and allows gas pressure to pass through the gas line to the door activated valve and into the chamber through the muffler 32 exhaust. If the position valve 48 is also open, then essentially the gas through the gas line of the door activated valve doubles the flow rate of air into the chamber. The door activated valve opens when air passes to it from the switch 40 but prevents air flow in the opposite direct in from the muffler 32 back to the switch 40. In this way, whenever the door 14 is open to any degree, increased airflow is applied to the chamber to maintain positive pressure and keep out the mine environment. [0032] The door activated switch 40, as shown in figure 2, has a button 80 that is positioned in the door frame 82 at the hinge 86 side of the door 14, as shown in figure 9. The button 80 is spring loaded so that when the door 14 becomes even slightly ajar, and a space is created between the door 14 and the frame, the button 80 will move out under the action of the spring 84, drawing a stem 88 of the button 80 which extends into a flow channel 90 through the switch 40, out of the flow channel 90, allowing air to flow through the flow channel 90 in the switch 40 and to the door activated valve 50. The air then flows through the door activated valve 50 and through the line to the exhaust muffler 32. When the door 14 becomes closed, the door 14 pushes down on the button 80, directing the stem 88 back into the flow channel 90, which closes the switch 40 and stops air flow to the door operated valve. The 6.48 CFM orifice 56 downstream from the door activated valve allows air flow at 6.48 cfm from the door activated switch 40 to the muffler 32. [0033] As a safety measure, a pressure relief valve 92 is located in the upper right rear corner of the steel chamber 16 to allow any excess air pressure to vent from the chamber, if 53832021 (GHMatters) P97023.AU 13/05/14 11 necessary, as shown in figure 4. In a preferred embodiment, there is no C02 scrubber in the change over station to remove carbon dioxide. The positive pressure maintained in the change over station 10 and constant flow of air into the chamber 16 effectively pushes out or keeps out toxic gases such as carbon dioxide while the miners are in the change over station, which is less than an hour or two hours, long enough for the miners to resupply themselves, have a short rest and make a determination where they will go next in the mine. [0034] In another embodiment, figure 2 shows a plumbing schematic and figures 3a, 3 and 3c show an overhead view, side view and front view, respectively, of the control panel 42. This schematic of the plumbing layout is slightly different then the layout of figure 1 and essentially operates the same way except as follows. From the plumbing schematic, the air flow from the cylinders 22 will go to the system valve 68, a Parker Veriflo HCV Valve with HP Gauge. The flow stops there until that valve 68 is turned on. What that means is that this is an always off system until the initial valve 68 is turned on. Once, the valve 68 is turned on, the flow then can take two directions. [0035] 1) The flow can go to the primary valve 46, a Parker Veriflo NV17 Indicator Valve ('On' / 'Stand-By' Valve) and [0036] 2) The flow can go to the secondary valve, a Parker Veriflo Door Activated 2 Position 3 Way Normally Closed switch [0037] In the panel 42 shown in figures 1, 2 and 3a-3c, the miners will be told by written instructions to turn the Parker Veriflo NV17 Indicator Primary Valve 46 to the 'On" position, so initially the flow will go through that valve 46 and through a 6.48 CFM orifice 56 to the muffler 32. Once, the miners open the door 14 to go into the chamber 16, the Parker Veriflo Door Activated Switch 40 will be activated and the flow of air will also be directed through the switch 40 to the Parker Veriflo NV17 AOP Secondary Valve 50 and through a 6.48 CFM orifice 56 to join the flow of air flowing through the Parker Veriflo NV17 Indicator Primary Valve 46 and exhaust at a total flow rate of about 13 cfm. The switch 40 and the AOP 53832021 (GHMatters) P97023.AU 13/05/14 12 Secondary Valve 50 work the same way as the switch 40 and door activated valve described above. [0038] After all the miners enter the COS, the door 14 will be shut and the switch 40 closed, The flow of air will then only flow to the Parker Veriflo NV17 Indicator Primary Valve through the 'On" position and the flow will be 6.48 cfm out the muffler 32. Once the miners exit the COS, they will go back to the control panel and turn the Parker Veriflo NV17 Indicator Primary Valve to 'Stand-By' and then the flow to the exhaust will be 0.6 cfm. [0039] From the Control Panel, step by step what miners would do: [0040] 1) Turn 'ON' the Parker Veriflo HCV System Valve with HP Gauge (far left valve on drawing panel figure 2) [0041] 2) Turn the Parker Veriflo NV17 Indicator Primary Valve to the 'ON' Position (far right valve in middle on drawing panel figure 2) [0042] 3) Open Entry Door and enter the COS: [0043] a. Where the mechanically operated Parker Veriflo Door Activated Switch will be activated, miners don't have to know about this because they will not have to turn or activate this switch [0044] 4) Close Entry Door once everyone has entered the COS [0045] a. Where the mechanically operated Parker Veriflo Activated Switch will be deactivated [0046] 5) After miners exit Close Entry Door and go over to the Valve panel and turn the Parker Veriflo NV17 Indicator Primary Valve to 'Stand-By' [0047] These steps will be a continuous loop until all the air is exhausted from the compressed air cylinders 22 or all the miners have been to the COS. 53832021 (GHMatters) P97023.AU 13/05/14 13 [0048] Although the invention has been described in detail in the foregoing embodiments for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be described by the following claims. [0049] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 53832021 (GHMatters) P97023.AU 13/05/14

Claims

1. A change over station (COS) for persons in a hazardous environment comprising: a steel housing having only a single door, a chamber, and an entrance portion, the door opening to the air lock portion, the air lock portion connected to the chamber; a first elongate seat disposed in the chamber; a plurality of compressed gas cylinders disposed in the seat; plumbing connected to the gas cylinders formed of gas lines and valves and an exhaust muffler, including a first gas path through the lines that provides a continuous flow or gas into the chamber through the muffler at a rate of greater than 4 cfm when the plumbing is in an on state, a second gas path through the lines that provides a continuous flow of gas into the chamber through the muffler at a rate of less than 1.5 cfm when the plumbing is in a standby state, and a third gas path through the lines which is door activated when the door is opened by a door activated switch which provides additional gas flow as long as the door is open at a rate of greater than 4 cfm into the chamber through the muffler; a valve control panel through which the plumbing extends and which is disposed on the outside of the housing which controls whether the plumbing is in the on state or the standby state; and a storage portion disposed in the housing having supplies, including water and SCSRs or SCBAs.

2. The COS of claim 1 wherein the plumbing includes a primary valve that controls whether gas from the gas cylinders follows the first path or the second path.

3. The COS of Claim 2 where the primary valve is a 3 way valve, Off, On, and Standby; 53832021 (GHMatters) P97023.AU 13/05/14 15 a. Off -off b. On- chamber is ready for entry c. Standby-chamber is activated with a trickle purge to keep the chamber clear of harmful gas after a first entry until a subsequent group arrives at the COS.

4. The COS of claim 3 wherein the plumbing through the first path and the second path creates positive pressure to keep contaminants out when the door is open.

5. The COS of claim 4 wherein the door activated switch at the door activates a secondary valve of the plumbing that increases gas flow rate into the chamber and blows gas out the open door.

6. The COS of claim 5 wherein the chamber has a net height of 60" and the housing has a flat top to maximize interior head room.

7. The COS of claim 6 wherein the seat height is about 16" to allow for a 6' person to sit upright in the chamber.

8. The COS of claim 7 wherein the housing is approximately 12' long and narrow enough that it fits in a shipping container. 3 units in a 40' container.

9. The COS of claim 8 which handles 3 sequenced 10 man change over for a total of 10 men.

10. The COS of claim 9 including a second elongate seat and wherein seat provides 24"of space per man, and the seats provide gas cylinder storage for up to 8 bottles is available.

11. The COS of claim 10 wherein the storage portion serves as storage for 30 SCSRs as well as 90 quarts of water. 53832021 (GHMatters) P97023.AU 13/05/14 16

12. The COS of claim 11 wherein the plumbing includes an orifice and compressed gas flow control would be facilitated via the orifice.

13. The COS of claim 12 wherein the space under the seats will allow for up to 8 bottles or a maximum of 4 hours in the ON mode, the standby mode substantially extends the reserve time by only releasing a trickle flow to maintain a slight positive pressure.

14. The COS of claim 13 wherein the storage portion of the water and SCSRs are left and right just inside the door for easy access.

15. The COS of claim 14 including hanging plastic curtain strips to help isolate the COS atmosphere from the mine.

16. The COS of claim 15 wherein the control panel is recessed to prevent damage and is provided with a tamper evident seal.

17. A method for providing a protected environment to miners from a mine environment in a mine comprising the steps of: opening a primary valve disposed in a control panel located on the outside of a steel housing of a change over station (COS) to an on state which causes compressed gas from compressed gas cylinders inside the housing to flow through a first flow path of plumbing in the steel housing into the chamber of the housing and create positive pressure in the chamber relative to the mine environment; opening a door of the housing which activates a door activated switch that causes compressed gas from the compressed gas cylinders to flow through a third flow path of the plumbing into the chamber of the housing and add to the flow through the first flow path of compressed gas into the chamber to increase the positive pressure in the chamber and to direct gas flow out of the chamber and through the open door; miners entering the chamber through the door, the miners taking SCSRs or SCBAs from a storage portion in the housing and the miners using the SCSRs or SCBAs; 53832021 (GHMatters) P97023.AU 13/05/14 17 closing the door of the housing which deactivates the door activated switch stopping compressed gas flow through the third flow path; and turning the primary valve to a standby state which causes the compressed gas from the compressed gas cylinders to flow through a second flow path of the plumbing into the chamber and a flow rate that is less than the rate of flow of compressed gas through the first flow path.

18. The method of claim 17 including the step of the miners communicating from inside the chamber with a location outside of the chamber.

19. The method of claim 17 including the steps of the miners leaving the COS and going to a refuge shelter and entering the refuge shelter. 53832021 (GHMatters) P97023.AU 13/05/14