FORCE BALANCE NEEDLE VALVE PRESSURE REGULATOR FOR CARBON DIOXIDE BASED CHROMATOGRAPHY

摘要

Exemplary embodiments of the present disclosure relate to systems and methods comprising a dynamic pressure regulator and a force balance needle that regulate pressure changes due to flow or composition changes in a pressurized flow system, such as, for example, a CO2-based chromatography system.

主权项

1. A method for controlling the pressure of a mobile phase in a chromatographic system, comprising:
introducing a mobile phase through a port on a head portion of a regulator comprising a needle and a seat defining a bore, creating a first pressure located in said head portion between said port and the seat, wherein the mobile phase is restricted by a gap between the needle and an edge of the bore to create a second pressures on a portion of the needle extending into the seat; and applying a control signal to a force actuator positioned to communicate with a back portion of said needle to generate an actuator force, such that said actuator force substantially counterbalances said first and second pressures on a front portion of said needle; wherein changes in said control signal result in movement of said needle to balance said actuator force and a needle tip force equal to a sum of the first pressure times a first control area and the second pressure times a second control area.