Dual diaphragm pump

• US 6,561,774 B2
• Filed: 05/31/2001
• Issued: 05/13/2003
• Est. Priority Date: 06/02/2000
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Layman, Fredrick
• Primary Examiner(s): Freay, Charles G.
• Assistant Examiner(s): Liu, Han L
• Application Number:
  US09/872,634
• Publication Number:
  US 20010048882A1
• Time in Patent Office: 712 Days
• Field of Search: 417/395, 417/383, 417/389, 417/534, 417/536, 417/412, 417/413.1, 92/99, 921/00, 921/01, 92/96, 921/38
• US Class Current: 417/395
• CPC Class Codes: F04B 43/025 two or more plate-like pumping members in parallel
• CPC Class Codes: F04B 43/0736 with two or more pumping chambers in parallel

Abstract

A dual diaphragm pump comprises a first chamber, a second chamber, a mechanical link, and a drive mechanism. The first chamber comprises a first cavity and a first diaphragm. The first chamber couples a pump inlet to a pump outlet. The second chamber comprises a second cavity and a second diaphragm. The second chamber couples the pump inlet to the pump outlet. The mechanical link couples the first diaphragm of the first chamber to the second diaphragm of the second chamber. The drive mechanism couples to the first diaphragm and the second diaphragm. In operation, the drive mechanism drives the first diaphragm causing first fluid within the first cavity to exit the pump outlet while causing second fluid to be drawn from the pump inlet into the second cavity. Further in operation, the mechanical link imparts an inlet pressure force from the second diaphragm to the first diaphragm.

Claims

1. A pump for pumping a supercritical fluid comprising:

a. a first chamber comprising a first cavity and a first diaphragm, the first chamber coupled to a pump inlet and a pump outlet;

b. a second chamber comprising a second cavity and a second diaphragm, the second chamber coupled to the pump inlet and the pump outlet;

c. a mechanical link coupling the first diaphragm of the first chamber to the second diaphragm of the second chamber; and

d. a drive mechanism coupled to the mechanical link, wherein the drive mechanism drives the mechanical link to actuate the first diaphragm and the second diaphragm in opposing directions, wherein the mechanical link directly applies a force to the first diaphragm and the second diaphragm such that the force drives the first diaphragm, thereby causing supercritical fluid within the first cavity to exit the pump outlet while causing supercritical fluid to be drawn from the pump inlet into the second cavity and further such that in operation the mechanical link imparts an inlet pressure force from the second diaphragm to the first diaphragm.

2. The pump of claim 1 wherein the first chamber comprises a first inlet check valve coupling the pump inlet to the first chamber and further wherein the first chamber comprises a first outlet check valve coupling the first chamber to the pump outlet.

3. The pump of claim 1 wherein the second chamber comprises a second inlet check valve coupling the pump inlet to the second chamber and further wherein the second chamber comprises a second outlet check valve coupling the second chamber to the pump outlet.

4. The pump of claim 1 wherein the mechanical link comprises a solid link.

5. The pump of claim 1 wherein the mechanical link comprises a liquid link.

6. The pump of claim 5 wherein the liquid link comprises an hydraulic link.

7. The pump of claim 1 wherein the mechanical link comprises a gas link.

8. The pump of claim 7 wherein the gas link comprises an pneumatic link.

9. A pump for pumping a supercritical fluid comprising:

a. a first chamber comprising a first cavity and a first diaphragm;

b. a first inlet check valve coupling the first chamber to a pump inlet;

c. a first outlet check valve coupling the first chamber to a pump outlet;

d. a second chamber comprising a second cavity and a second diaphragm;

e. a second inlet check valve coupling the second chamber to the pump inlet;

f. a second outlet check valve coupling the second chamber to the pump outlet;

g. a mechanical link coupling the first diaphragm of the first chamber to the second diaphragm of the second chamber; and

h. a drive mechanism coupled to the mechanical link, wherein the drive mechanism drives the mechanical link to apply a selective force to the first diaphragm and the second diaphragm.

10. A method of pumping a supercritical fluid at an elevated gauge pressure comprising the steps of:

a. balancing a first diaphragm of a first diaphragm pump chamber against a second diaphragm of a second diaphragm pump chamber using a mechanical link;

b. driving the mechanical link to apply a force to the first diaphragm to impart a differential work to the supercritical fluid within the first diaphragm pump chamber where the differential work corresponds proximately to a first product of a pump head pressure and a displaced volume of the first diaphragm pump chamber; and

c. assisting the first diaphragm pump chamber using the mechanical link between the first and second diaphragms to impart a baseline work corresponding proximately to a second product of the elevated gauge pressure and the displaced volume of the first diaphragm chamber.

11. A supercritical fluid circulation loop comprising:

a. a supercritical processing chamber having a first circulation line and a second circulation line; and

b. a pump for circulating a supercritical fluid with the supercritical processing chamber, the pump further comprising;

i. a first chamber having a first cavity and a first diaphragm, the first chamber coupled to the first circulation line and the second circulation line;

ii. a second chamber comprising a second cavity and a second diaphragm, the second chamber coupled to the first circulation line and the second circulation line; and

iii. an actuator assembly coupled to the first diaphragm and the second diaphragm, such that the actuator assembly causes the supercritical fluid within the first cavity to exit the second circulation line while causing the supercritical fluid to be drawn from the first circulation line into the second cavity by imparting an inlet pressure force from the second diaphragm to the first diaphragm.

12. The supercritical fluid circulation loop according to claim 11 further comprising:

a. a reservoir having a fluid;

b. a high pressure pump coupled to the reservoir, wherein the high pressure pump pumps the fluid to the supercritical processing chamber; and

c. a valve coupled to the high pressure pump, wherein the valve is closed when the fluid has reached a supercritical state.

13. The supercritical fluid circulation loop according to claim 11, wherein the pump further comprises a first inlet check valve coupling the first circulation line to the first chamber and further wherein the first chamber comprises a first outlet check valve coupling the first chamber to the second circulation line.

14. The supercritical fluid circulation loop according to claim 11, wherein the pump further comprises a second inlet check valve coupling the first circulation line to the second chamber and further wherein the second chamber comprises a second outlet check valve coupling the second chamber to the second circulation line.

15. The supercritical fluid circulation loop according to claim 11 wherein the actuator assembly further comprises:

a. a mechanical link coupled to the first diaphragm and the second diaphragm; and

b. a drive mechanism coupled to mechanical link, wherein the drive mechanism drives the mechanical link between a first position and a second position.

16. The supercritical fluid circulation loop according to claim 15, wherein the mechanical link further comprises a solid link.

17. The supercritical fluid circulation loop according to claim 15, wherein the mechanical link comprises a liquid link.

18. The supercritical fluid circulation loop according to claim 17, wherein the liquid link comprises an hydraulic link.

19. The supercritical fluid circulation loop according to claim 15, wherein the mechanical link comprises a gas link.

20. The supercritical fluid circulation loop according to claim 19, wherein the gas link comprises an pneumatic link.

21. A pump for pumping a supercritical fluid, the pump coupled to a pump inlet and a pump outlet, wherein the supercritical fluid is at an elevated gauge pressure at the pump inlet, the pump comprising:

a. a first chamber having a first cavity and a first diaphragm, the first chamber coupled to the pump inlet and the pump outlet, wherein the first diaphragm moves between a first position and a second position, the first diaphragm in the first position when the supercritical fluid is within the first chamber;

b. a second chamber having a second cavity and a second diaphragm, the second chamber coupled to the pump inlet and the pump outlet, wherein the second diaphragm moves between a third position and a fourth position, the second diaphragm in the fourth position when the supercritical fluid is in the second chamber; and

d. a mechanical link for driving the first diaphragm from the first position to the second position using a driving force, wherein the driving force includes the elevated gauge pressure of the supercritical fluid entering the second chamber when the second diaphragm is moving between the third position and the fourth position.

22. The pump according to claim 21 wherein the driving force further includes a head pressure force supplied directly from the drive assembly.