Claims
- 1. A flow-through vacuum degassing unit for degassing one or more liquids comprising:
a vacuum chamber adapted to be connected to a source for creating a vacuum in the chamber; inlet and outlet connections for admitting and discharging liquid to be degassed; a continuous tube for conducting the liquid through the chamber, the tube being connected between the inlet and the outlet connection and the tube being formed of a polymeric material permeable to pass dissolved gasses therethrough but liquid impermeable; and control means for operating the source for creating a vacuum in the chamber responsive to a sensed vacuum level in the chamber, with said control means being designed to operate of said vacuum source at a relatively rapid rate during initial pump down, and being further adapted to operate said vacuum source at a substantially steady but lower rate after a desired level of vacuum has been achieved.
- 2. The apparatus of claim 1 wherein the continuous tube have a single lumen.
- 3. The apparatus of claim 1 wherein the continuous tube has multiple lumens.
- 4. The apparatus of claim 1 wherein the polymeric material consists essentially of amorphous perfluorinated copolymer.
- 5. The apparatus of claim 4 wherein said chamber inlet and outlet connections to said continuous tube comprise inverted ferrule couplings.
- 6. The apparatus of claim 1 wherein the source for creating a vacuum further comprises a two stage, series pump.
- 7. The apparatus of claim 6 wherein a first stage of the pump is continuously vented through a sintered metal plug.
- 8. The apparatus of claim 6 wherein a second stage of the pump is continuously vented through a sintered metal plug.
- 9. The apparatus of claim 6 wherein both stages of the pump are continuously vented through sintered metal plugs.
- 10. The apparatus of claim 6 wherein the pump further comprises a unitary diaphragm.
- 11. The apparatus of claim 6 wherein the pump is driven by a variable-speed motor.
- 12. The apparatus of claim 11 wherein the variable-speed motor is a brushless DC stepper motor.
- 13. The apparatus of claim 11 wherein the control means is operable to drive the motor in a first mode of operation in which the motor is driven at a high RPM to evacuate the vacuum chamber and at a low RPM for continuous operation of the degassing unit, a second mode of operation in which the motor is driven intermittently to maintain a set vacuum within the vacuum chamber, and a third mode of operation in which the motor is driven at varying rpms to maintain a constant vacuum within the vacuum chamber.
- 14. The apparatus of claim 3 wherein the vacuum chamber inlet and outlet connections further comprise an interface grid disposed between a bulkhead fitting and a nut, the interface grid being formed of TEFZEL® and having a center bore and a plurality of radially spaced bores adapted for adhesiveless sealing of the multiple lumen tube therethrough.
- 15. The apparatus of claim 1 wherein the vacuum chamber further comprises an elongate tube.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation-in-part of our copending application Ser. No. 09/378,592, filed Aug. 20, 1999, entitled “VACUUM DEGASSING”, and assigned to the same assignee as the present application.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09378592 |
Aug 1999 |
US |
Child |
09735333 |
Dec 2000 |
US |