Patent ID: 6769301
Filing Date: 2004-08-03
Classification: G01F,G05D

Abstract:
A Coriolis mass flow controller, comprising:a flow inlet; a flow outlet; a flow sensor tube having first and second ends in fluid communication with the flow inlet and flow outlet, respectively; a drive device situated adjacent the flow sensor tube so as to cause the flow sensor tube to vibrate; a position sensing device situated adjacent the flow sensor tube so as to measure the twist in the flow sensor tube due to Coriolis force; a meter body having a first end in fluid communication with the flow inlet and a second end in fluid communication with the flow outlet, the meter body receiving the first and second ends of the flow sensor tube; a valve coil situated in the meter body; a valve stem received by the valve coil; a plunger received by the valve coil; a valve body connected to the meter body with a seal therebetween; a valve seat positioned in the valve body, the plunger being adapted to seal against the valve seat; and a processor coupled to the position sensing device and receiving an indication of a desired mass flow rate, wherein the processor is programmed to determine the actual mass flow rate based on the measured twist in the flow sensor tube due to Coriolis force, and manipulate the plunger relative to the valve seat in response to the desired mass flow rate and the actual mass flow rate.