Gas pressure feed device

Abstract

Provided is a gas pressure feed device capable of appropriately suppressing an increase in gas pressure in a system without inducing complications of control and system or increase in size. The gas pressure feed device ( 1 ) comprises a compression device ( 2 ) for compressing gas supplied from the upstream process and sending the gas to the downstream process; a shut off device ( 4 ) provided in the downstream further than the compression device for shutting off the gas heading toward the downstream process; and a recirculation device ( 6 ) for recirculate the gas shut off by the shut off device to the upstream of the compression device, and the shut off device includes a first port ( 11 ) on a primary side for introducing the gas from the compression device, a second port ( 12 ) on a secondary side for sending the gas to the downstream process, a third port ( 13 ) on the secondary side for sending the gas to the recirculation device, and a switching device ( 14 ) for switching the gas heading toward the secondary side to either the second port or the third port.

1 . A gas pressure feed device comprising:
 a compression device for compressing gas supplied from an upstream process and sending the gas to a downstream process;   a shut off device provided downstream from the compression device for shutting off the gas heading toward the downstream process; and   a recirculation device for recirculating the gas shut off by the shut off device to the upstream process of the compression device, wherein the shut off device includes   a first port on a primary side for introducing the gas from the compression device,   a second port on a secondary side for sending the gas to the downstream process,   a third port on the secondary side for sending the gas to the recirculation device, and   a switching device for switching the gas heading toward the secondary side to either the second port or the third port, wherein the shut off device comprises a tubular valve port and a driving device for rotationally driving the valve port (“inner port”) axially, wherein the valve port is provided with the first port on one side in an axial direction, and the second port at a predetermined position in a circumferential direction, and the third port at a position circumferentially deviated from the second port, and wherein rotational movement of the valve port (“inner port”) by the driving device constituting the switching device switches between a first position in which the gas is sent from the second port to the downstream process and a second position in which the gas is recirculated from the third port to the recirculation device.   
     
     
         2 . The gas pressure feed device according to  claim 1 , wherein in an intermediate stage of switching by the switching device, the shut off device continues to send the gas toward at least one of the second port and the third port.