| US 7,461,465 B2 | ||
| Pressure control in centrifugal evaporators | ||
| Roger Lee-Smith, Hadleigh (United Kingdom) | ||
| Assigned to Genevac Ltd., Ipswich, Suffolk (United Kingdom) | ||
| Appl. No. 10/526,976 PCT Filed Oct. 29, 2003, PCT No. PCT/GB03/04681 § 371(c)(1), (2), (4) Date Aug. 22, 2005, PCT Pub. No. WO2004/040214, PCT Pub. Date May 13, 2004. |
||
| Claims priority of application No. 0225329.2 (GB), filed on Oct. 31, 2002. | ||
| Prior Publication US 2006/0101664 A1, May 18, 2006 | ||
| Int. Cl. F26B 5/04 (2006.01); F26B 13/30 (2006.01) | ||
| U.S. Cl. 34—403 [34/92] | 8 Claims |
| 1. A method of operating a vacuum drying chamber having a vent valve, a non-return valve leading to a vacuum pump and a pressure
control valve which communicates with the inlet to the pump, comprising the steps of:
(a) closing the vent valve;
(b) opening the pressure control valve, thereby allowing air at atmospheric pressure to enter through the pressure control
valve and subjecting the non-return valve to atmospheric pressure on the pump side; and
(c) subjecting the non-return valve to a lower at least partial vacuum pressure in the chamber on the other side, such that
the differential pressure keeps the non-return valve closed, thereby sealing the chamber from atmosphere while the open pressure
control valve provides a ready supply of air at atmospheric pressure to the pump inlet which thus maintains a high flow rate
therethrough, thereby to clear any solvent from the interior of the pump.
|