Control valve and air starting system

Abstract

A method of slow starting a combustion engine with an air starting system having a pressure source coupled to an air starter via a control valve, the method comprising: supplying bursts of air from the pressure source to the air starter by reciprocating a piston of the control valve between an opened position and a closed position.

What is claimed is: 
     
         1 . A method of slow starting a combustion engine with an air starting system having a source of pressurized air fluidly coupled to an air starter via a control valve, the method comprising: supplying bursts of air from the pressure source to the air starter by reciprocating a piston of the control valve between an opened position and a closed position, with selective application of a pull force to the piston to counter, in combination with a push force applied to the piston by the pressurized air, a normally-closing biasing force acting on the piston. 
     
     
         2 . The method of  claim 1  further comprising flowing a fluid from the pressure source to an inlet of the control valve to produce the push force on the piston. 
     
     
         3 . The method of  claim 1  further comprising closing the valve by applying a biasing force on the piston with a biasing element. 
     
     
         4 . The method of  claim 3  wherein moving the piston to the opened position occurs when the push force and the pull force in combination overcome the biasing force. 
     
     
         5 . The method of  claim 1  further comprising linearly moving a shaft connected to the piston to move the piston between the closed and opened positions with a linear motor coupled to the shaft. 
     
     
         6 . The method of  claim 5  further comprising passing electricity through an electromagnetic coil to generate a magnetic field that interacts with a permanent magnet to apply a force on the shaft. 
     
     
         7 . The method of  claim 6  wherein passing electricity through the electromagnetic coil in a first direction generates the pull force on the shaft. 
     
     
         8 . The method of  claim 7  wherein passing electricity through the electromagnetic coil in a second direction opposite the first direction generates a pushing force on the shaft pushing the piston toward the closed position. 
     
     
         9 . The method of  claim 1  further comprising forming a flow passage between an inlet of the control valve fluidly coupled to the pressure source and an outlet of the control valve fluidly coupled to the air starter when the piston is in the opened position. 
     
     
         10 . The method of  claim 9  further comprising flowing pressurized air from the inlet to the outlet. 
     
     
         11 . The method of  claim 10  wherein the pressurized air is flowing at a flow rate is up to and including 1700 scfm. 
     
     
         12 . The method of  claim 1  wherein moving the piston from the closed to the opened position occurs in 30 ms or less. 
     
     
         13 . The method of  claim 1  wherein the piston moves from the closed to the opened position when an inlet pressure is up to and including 150 psig. 
     
     
         14 . A method of operating an air starting system having a pressure source coupled to an air starter via a control valve, the method comprising:
 supplying bursts of air from the pressure source to the air starter to reciprocate a piston of the control valve between an opened position and a closed position;   biasing the piston toward the closed position by applying a biasing force with a biasing element;   flowing a fluid from the pressure source to an inlet of the control valve to apply a push force on the piston;   generating a pull force on the piston which when combined with the push force is sufficient to overcome the biasing force to move the piston to the opened position; and   removing at least one of the push force or the pull force to move the piston to the closed position.   
     
     
         15 . The method of  claim 14  further comprising linearly moving a shaft connected to the piston to move the piston between the closed and opened positions with a linear motor coupled to the shaft. 
     
     
         16 . The method of  claim 15  further comprising passing electricity through an electromagnetic coil to generate a magnetic field that interacts with a permanent magnet to apply a force on the shaft. 
     
     
         17 . The method of  claim 16  wherein passing electricity through the electromagnetic coil in a first direction generates the pull force on the shaft. 
     
     
         18 . The method of  claim 17  wherein passing electricity through the electromagnetic coil in a second direction opposite the first direction generates a pushing force on the shaft pushing the piston toward the closed position. 
     
     
         19 . The method of  claim 14  further comprising forming a flow passage between the inlet and an outlet of the control valve fluidly coupled to the air starter when the piston is in the opened position. 
     
     
         20 . The method of  claim 19  further comprising flowing pressurized air from the inlet to the outlet.