Change Over Station and Method

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.

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;
 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. 
     
     
         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;   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.