Patent ID: 9158308
Filing Date: 2015-10-13
Classification: F04B,G05D,Y10T

Abstract:
1. A flow controller comprising: a housing including a first port, a second port, and a cavity, the cavity having a piston that varies a volume of the cavity by undergoing a compression stroke and expansion stroke during operation of the pressure controller; a first control valve having an open state and a closed state, the first control valve selectively connecting the cavity in fluid communication with a fluid source via the first port when the first control valve is in the open position; a second control valve having an open state and a closed state, the second control valve selectively connecting the cavity in fluid communication with a system to be controlled via the second port when the second control valve is in the open position; and a computing device configured to actuate the first control valve and the second control valve between the open and closed states so as to operate the pressure controller in two modes of operation, a first mode of operation being as a compressor configured to supply fluid from the fluid source to the system, and a second mode of operation being as a vacuum pump configured to remove fluid from the system, and during the first mode of operation the computing device is configured to achieve a flow rate from a maximum flow rate to a minimum flow rate, wherein at the maximum flow rate, the first control valve is opened when the piston reaches the end of the compression stroke and the second control valve is opened when the piston reaches the end of the expansion stroke, and wherein at the minimum flow rate, the first control valve is opened late in the expansion stroke and the second control valve is opened late in the compression stroke.