Title:
METHOD AND APPARATUS FOR REDUCING NOISE IN A ROOTS-TYPE BLOWER
Document Type and Number:
WIPO Patent Application WO2006022787
Kind Code:
A3
Abstract:
A Roots-type blower comprises a housing defining a rotor chamber and an inlet and outlet to the rotor chamber. First and second rotors are mounted in the rotor chamber, each rotor defining a plurality of lobes, adjacent lobes and the housing cooperating to define gas transport chambers. The blower is configured so that a net flow rate of gas into a gas transport chamber is generally or approximately constant, whereby a change in gas pressure in the gas transport chamber is generally or approximately linear, as the gas transport chamber approaches the outlet. In one embodiment, this is accomplished by providing flow channels extending from the outlet towards the inlet, and from the inlet towards the outlet, corresponding to each rotor. The flow channels permit gas to flow from the high pressure outlet to a gas transport chamber and from the gas transport chamber to the low pressure inlet. The resulting amelioration of pressure spikes associated with flow back substantially reduces the operational noise level of the blower.
Inventors:
DEVRIES DOUGLAS F (US)
WILLIAMS MALCOLM (US)
WILLIAMS MALCOLM (US)
Application Number:
PCT/US2004/037659
Publication Date:
December 21, 2006
Filing Date:
November 10, 2004
Export Citation:
Assignee:
PULMONETIC SYSTEMS INC (US)
International Classes:
A61M16/00; A47C3/025; A62B7/00; F01C1/18; F04C18/12; F04C29/00; H02P6/16; A61M11/00; A61M16/10; A61M16/12; A61M16/20; A61H
Foreign References:
| US6484719B1 | 2002-11-26 | |||
| US5823186A | 1998-10-20 |
Other References:
See also references of EP 1773434A4
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