High purity fluid delivery system

Abstract

A fluid delivery system includes a flow control device and a Coriolis mass flowmeter in fluid communication with the flow control device. The Coriolis flowmeter has a flow-tube made of a high-purity plastic material, such as PFA, making the delivery system suitable for high purity applications. A controller provides a control output signal to the flow control device, which may comprise a pinch valve, so as to vary the flow control device output in response to a setpoint signal and measurement signals received from the flowmeter.

What is claimed is: 
     
       1. A fluid delivery system, comprising:
 a reservoir having an inlet for receiving a gas to pressurize the reservoir and an outlet for dispensing fluid contained in the reservoir, with the reservoir including a flexible liner that holds the fluid and prevents the gas from passing into the fluid delivery system; 
 a first flow control device connected to the reservoir inlet; 
 a first pressure transmitter connected to the reservoir inlet, the first pressure transmitter providing an output a reservoir inlet pressure signal; 
 a second flow control device in fluid communication with the reservoir outlet to control fluid flow out of the reservoir; 
 a second pressure transmitter connected to the reservoir outlet, the second pressure transmitter providing an output a reservoir outlet pressure signal; 
 a Coriolis mass flowmeter in fluid communication with the second flow control device, the Coriolis flowmeter having a flow-tube made of a high-purity plastic material, the Coriolis flowmeter providing an output signal a mass flow rate output signal of a reservoir output flow from the reservoir and providing a density measurement for the fluid; 
 a controller receiving a setpoint signal, the controller receiving the output signals reservoir inlet pressure signal from the first and second pressure transmitters and pressure transmitter, the reservoir outlet pressure signal from the second pressure transmitter, and the mass flow rate output signal and the density measurement from the Coriolis flowmeter and providing control output signals to the first and second flow control devices to vary the pressure of the reservoir and the flow rate of fluid from the reservoir. 
 
     
     
       2. The fluid delivery system of  claim 1 , wherein the high-purity plastic material comprises PFA. 
     
     
       3. The fluid delivery system of  claim 1 , wherein the second flow control device comprises a valve. 
     
     
       4. The fluid delivery system of  claim 3 , wherein the valve comprises a pinch valve. 
     
     
       5. The fluid delivery system of  claim 4 , wherein the pinch valve comprises:
 an actuator having a ram operatively connected thereto; 
 a reference surface positioned generally opposite the ram; 
 a high purity, flexible tube positioned between the ram and the reference surface. 
 
     
     
       6. The fluid delivery system of  claim 5 , wherein the actuator comprises a solenoid. 
     
     
       7. The fluid delivery system of  claim 5 , wherein the actuator comprises a stepper motor. 
     
     
       8. The fluid delivery system of  claim 1 , wherein the second flow control device comprises a pump having a variable output. 
     
     
       9. The fluid delivery system of  claim 8 , wherein the pump comprises a peristaltic pump. 
     
     
       10. The fluid delivery system of  claim 1 , wherein the reservoir includes a bag situated therein for containing a fluid. 
     
     
       11. The fluid delivery system of  claim 1 , wherein the controller comprises a PID controller. 
     
     
       12. The fluid delivery system of  claim 1 , wherein the output signal provided by the Coriolis mass flowmeter includes a mass flowrate measurement. 
     
     
       13. The fluid delivery system of  claim 1 , wherein the output signal provided by the Coriolis mass flowmeter includes a fluid density measurement. 
     
     
       14. The fluid delivery system of  claim 1 , wherein the output signal provided by the Coriolis mass flowmeter includes a fluid temperature measurement. 
     
     
       15. A fluid delivery system, comprising:
 a reservoir having an inlet for receiving a gas to pressurize the reservoir and an outlet for dispensing fluid contained in the reservoir, with the reservoir including a flexible liner that holds the fluid and prevents the gas from passing into the fluid delivery system;   a first flow control device connected to the reservoir inlet;   a second flow control device in fluid communication with the reservoir outlet to control fluid flow out of the reservoir;   a second pressure transmitter connected to the reservoir outlet, the second pressure transmitter providing a reservoir outlet pressure signal;   a Coriolis mass flowmeter in fluid communication with the second flow control device, the Coriolis flowmeter having a flow-tube made of a high-purity plastic material, the Coriolis flowmeter providing mass flow rate output signal of a reservoir output flow from the reservoir and providing a density measurement for the fluid;   a third pressure transmitter connected to a Coriolis mass flowmeter output and generating a Coriolis flowmeter output pressure; and   a controller receiving a setpoint signal and receiving the reservoir outlet pressure signal from the second pressure transmitter, the Coriolis flowmeter output pressure from the third pressure transmitter, and the mass flow rate output signal and the density measurement from the Coriolis mass flowmeter, the controller providing control output signals to the first and second flow control devices to vary the pressure of the reservoir and the flow rate of fluid from the reservoir, and the controller determining a fluid viscosity from the mass flow rate, the reservoir outlet pressure, and the Coriolis flowmeter output pressure.   
     
     
       16. The fluid delivery system of claim 15, wherein the second pressure transmitter is connected to the reservoir outlet upstream of the Coriolis mass flowmeter. 
     
     
       17. The fluid delivery system of claim 15, further comprising a first pressure transmitter located at the inlet of the reservoir. 
     
     
       18. The fluid delivery system of claim 17, wherein the controller calculates the viscosity of fluid flowing through the system. 
     
     
       19. The fluid delivery system of claim 15, wherein the controller further controls a tool for processing a work piece. 
     
     
       20. The fluid delivery system of claim 15, wherein the controller comprises a fluid delivery controller, the system further comprising a tool controller that controls a tool for processing a work piece, the tool controller providing the setpoint signal to the fluid delivery controller. 
     
     
       21. The fluid delivery system of claim 15, further comprising a filter connected to the reservoir outlet. 
     
     
       22. The fluid delivery system of claim 15, wherein the second flow control device comprises a pinch valve. 
     
     
       23. The fluid delivery system of claim 15, wherein the second flow control device comprises a metering pump. 
     
     
       24. The fluid delivery system of claim 1, further comprising a third pressure transmitter connected to the Coriolis mass flowmeter output and generating a Coriolis flowmeter output pressure, wherein the controller receives the Coriolis flowmeter output pressure and receives the reservoir outlet pressure from the second pressure transmitter and determines a fluid viscosity from the mass flow rate, the reservoir outlet pressure, and the Coriolis flowmeter output pressure.