IMPROVEMENTS IN AND RELATING TO VACUUM CONDUITS

• US 20150292494A1
• Filed: 10/28/2013
• Published: 10/15/2015
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: Edwards Limited (Atlas Copco AB)
• Original Assignee: Edwards Limited (Atlas Copco AB)
• Inventors: Tattersall, Jack Raymond, Turner, Neil, Holbrook, Alan Ernest Kinnaird, Wickes, Matthew Richard
• Granted Patent: US 10,539,123 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F04B 11/0091 using a special shape of fluid pass, e.g. throttles, ducts
• CPC Class Codes: F04B 37/14 to obtain high vacuum
• CPC Class Codes: F04B 39/0055 with a special shape of fluid passage, e.g. bends, throttles, diameter changes, pipes
• CPC Class Codes: F04B 41/06 Combinations of two or more pumps
• CPC Class Codes: F04C 18/126 with radially from the rotor body extending elements, not necessarily co-operating with corresponding recesses in the other rotor, e.g. lobes, Roots type
• CPC Class Codes: F04C 25/02 for producing high vacuum sealing arrangements F04C27/00; silencing F04C29/06
• CPC Class Codes: F04C 28/28 Safety arrangements; Monitoring
• CPC Class Codes: F04C 29/124 with inlet and outlet valves specially adapted for rotary or oscillating piston pumps

Abstract

In situations where a vacuum system is suddenly overloaded, there is a risk of mechanical damage being sustained, for example, bearing damage, gear slippage or rotor and/or stator collisions. Sudden overloads can also lead to electrical damage, for example, over-currents or power surges. Therefore a pressure regulating apparatus is provided for use in a vacuum pumping system having an inlet, an outlet and a conduit interposed between, and in fluid communication with, the inlet and the outlet, wherein the cross-sectional area of the conduit is greater than that required to meet the conductance requirements of the inlet and the outlet.

Claims

1. A pressure regulating apparatus for use in a vacuum pumping system having an inlet, an outlet and a conduit interposed between, and in fluid communication with, the inlet and the outlet, wherein the cross-sectional area of the conduit is greater than that required to meet the conductance requirements of the inlet and the outlet.

2. The pressure regulating apparatus as claimed in claim 1, comprising at least one hollow expansion chamber in fluid communication with the conduit.

3. The pressure regulating apparatus as claimed in claim 2, wherein the at least one hollow expansion chamber provides excess free volume of the conduit for accumulating process gasses.

5. The manifold as claimed in claim 3, comprising an conduit portion having an inlet orifice sealingly connectable, in use, to the outlet of the booster pump, and an outlet orifice sealingly connectable, in use, to the inlet of the backing pump.

6. The manifold as claimed in claim 5, wherein the or each orifice comprises a generally planar connection flange connectable, in use, to a connection flange of the booster or backing pump.

7. The manifold as claimed in claim 6, wherein the orifices are aligned to at least partially overlap when viewed along a direction, in use, of the gas flowing through the manifold.

4. A manifold suitable for connecting the outlet of a booster pump to the inlet of a backing pump comprising a pressure regulating apparatus having an inlet, an outlet and a conduit interposed between, and in fluid communication with, the inlet and the outlet, wherein the cross-sectional area of the conduit is greater than that required to meet the conductance requirements of the inlet and the outlet.

8. The manifold as claimed in claim 4, further comprising at least one expansion chamber portion in fluid communication with the conduit portion.

9. The manifold as claimed in claim 8, wherein the combined volume of the conduit portion and the expansion chambers is between approximately 2 and 30 times the volume of the conduit portion.

10. The manifold as claimed in claim 8, wherein the combined volume of the conduit portion and the expansion chambers is between approximately 5 and 20 times the volume of the conduit portion.

11. The manifold as claimed in claim 8, wherein the combined volume of the conduit portion and the expansion chambers is between approximately 5 and 15 times the volume of the conduit portion.

12. The manifold as claimed in claim 8, wherein the combined volume of the conduit portion and the expansion chambers is between approximately 5 and 10 times the volume of the conduit portion.

13. The manifold as claimed in claim 8, wherein the combined volume of the conduit portion and the expansion chambers is approximately 7.5 times the volume of the conduit.

14. The manifold as claimed in claim 8, wherein the ratio of the combined interior free volume of the conduit portion and the expansion chambers to the largest anticipated process chamber volume is at least 0.2% of the ratio of the booster displacement to backing pump displacement

15. The manifold as claimed in claim 8, wherein the ratio of the combined interior free volume of the conduit portion and the expansion chambers to the largest anticipated process chamber volume is at least 1% of the ratio of the booster displacement to backing pump displacement.

16. The manifold as claimed in claim 8, wherein the manifold comprises a main body portion formed generally as a hollow box by a metal casting process.

17. The manifold as claimed in claim 8, wherein the conduit portion is internally shaped to provide a smooth and gradual transition between the shape and dimensions of the inlet and outlet apertures.

18. The manifold as claimed in claim 8, wherein the or each hollow expansion chamber portions extend radially outwardly from the conduit portion.

19. The manifold according to claim 8, further comprising an auxiliary port in fluid communication with the conduit portion.

21. The manifold according to claim 9, wherein a main body portion of the manifold comprises a structural support member for connection to either or both of the booster pump and the backing pump.

22. (canceled)

20. The manifold as claimed in claim 22, wherein the auxiliary port is formed as a through aperture in a side wall of one of the expansion chambers.

23. A vacuum system comprising a booster pump and a backing pump, said system further comprising a pressure regulating apparatus comprising an inlet, an outlet and a conduit interposed between, and in fluid communication with, the inlet and the outlet, wherein the cross-sectional area of the conduit is greater than that required to meet the conductance requirements of the inlet and the outlet, wherein said inlet of the pressure regulating apparatus is connected to, and in fluid communication with, the outlet of said booster pump and said outlet of the pressure regulating apparatus is connected to, and in fluid communication with, the inlet of said backing pump.

24. (canceled)