Patent ID: 6109881
Filing Date: 2000-08-29
Classification: F04B

Abstract:
A pump that utilizes gas and liquid mediums in separate chambers for dispensing process fluids comprising:a housing;a piston moveable within a portion of the housing to define first and second pump chambers, wherein the first pump chamber is designed to receive a substantially gas medium and the second pump chamber to receive a substantially fluid medium;a working element within the second pump chamber, wherein when the second chamber is filled with the fluid medium, the fluid medium displaces the working element;means for selectively varying pressure of the gas medium in the first chamber, wherein when the first chamber is filled with the gas medium, selective variation of the gas medium pressure providing selective displacement of the piston;a pressure controller for controlling the gas pressure in the first pump chamber;a position controller which determines the status of the piston and interacts with the pressure controller to control the position of the piston;a means for gauging the displacement of the piston due to pressure changes in the first pump chamber;a means for transmitting the displacement data to the position controller; anda means controlled by the pressure controller for changing the pressure in the first pump chamber.