Acoustic liner and a fluid pressurizing device and method...

Acoustics – Sound-modifying means – Sound absorbing panels

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C181S292000, C181S213000

Reexamination Certificate

active

06550574

ABSTRACT:

This invention relates to an acoustic liner and a fluid pressurizing device and method utilizing same.
Fluid pressurizing devices, such as centrifugal compressors, are widely used in different industries for a variety of applications involving the compression, or pressurization, of a gas. However, a typical compressor produces a relatively high noise level which is an obvious nuisance to the people in the vicinity of the device. This noise can also cause vibrations and structural failures.
For example, the dominant noise source in a centrifugal compressor is typically generated at the locations of the impeller exit and the diffuser inlet, due to the high velocity of the fluid passing through these regions. The noise level becomes higher when discharge vanes are installed in the diffuser to improve pressure recovery, due to the aerodynamic interaction between the impeller and the diffuser vanes.
Various external noise control measures such as enclosures and wrappings have been used to reduce the relative high noise levels generated by compressors, and similar devices. These external noise reduction techniques can be relatively expensive especially when they are often offered as an add-on product after the device is manufactured.
Also, internal devices, usually in the form of acoustic liners, have been developed which are placed in the compressors, or similar devices, for controlling noise inside the gas flow paths. These liners are often based on the well-known Helmholtz resonator principle according to which the liners dissipate the acoustic energy when the sound waves oscillate through perforations in the liners, and reflect the acoustic energy upstream due to the local impedance mismatch caused by the liner. Examples of Helmholtz resonators are disclosed in U.S. Pat. Nos. 4,100,993; 4,135,603; 4,150,732;.4,189,027; 4,443,751; 4,944,362; and 5,624,518.
A typical Helmholtz array acoustic liner is in the form of a three-piece sandwich structure consisting of honeycomb cells sandwiched between a perforated facing sheet and a back plate. Although these three-piece designs have been successfully applied to suppress noise in aircraft engines, it is questionable whether or not they would work in fluid pressurizing devices, such as centrifugal compressors. This is largely due to the possibility of the perforated facing sheet of the liner breaking off its bond with the honeycomb under extreme operating conditions of the compressor, such as, for example, during rapid depressurization caused by an emergency shut down of the compressor. In the event that the perforated facing sheet becomes loose, it not only makes the acoustic liners no longer functional but also causes excessive aerodynamic losses, and even the possibility of mechanical catastrophic failure, caused by the potential collision between the break-away perforated sheet metal and the spinning impeller.
Therefore what is needed is a system and method for reducing the noise in a fluid pressurizing device utilizing a Hemholtz array acoustic liner while eliminating its disadvantages.
SUMMARY
Accordingly an acoustic liner is provided, as well as a fluid processing device and method incorporating same, according to which the liner attenuates noise and consists of a plurality of cells formed in a plate in a manner to form an array of resonators.


REFERENCES:
patent: 1783276 (1930-12-01), Bliss
patent: 1972563 (1934-09-01), Irvin
patent: 3181646 (1965-05-01), Edwards
patent: 3360193 (1967-12-01), Harris et al.
patent: 3948346 (1976-04-01), Schindler
patent: 4135603 (1979-01-01), Dean, III et al.
patent: 4137992 (1979-02-01), Herman
patent: 4150850 (1979-04-01), Doerfling
patent: 4189027 (1980-02-01), Dean, III et al.
patent: 4190131 (1980-02-01), Robinson
patent: 4204586 (1980-05-01), Hani et al.
patent: 4241806 (1980-12-01), Metzger
patent: 4287962 (1981-09-01), Ingard et al.
patent: 4303144 (1981-12-01), Wirt
patent: 4421455 (1983-12-01), Tomren
patent: 4433751 (1984-02-01), Bonneau
patent: 4504188 (1985-03-01), Traver et al.
patent: 4848514 (1989-07-01), Snyder
patent: 4854416 (1989-08-01), Lalikos et al.
patent: 4926963 (1990-05-01), Snyder
patent: 4932835 (1990-06-01), Sorokes
patent: 4944362 (1990-07-01), Motsinger et al.
patent: 4947958 (1990-08-01), Snyder
patent: 5007499 (1991-04-01), Ebbing et al.
patent: 5014815 (1991-05-01), Arcas et al.
patent: 5025888 (1991-06-01), Arcas et al.
patent: 5099566 (1992-03-01), Barrett
patent: 5173020 (1992-12-01), Ebbing et al.
patent: 5173021 (1992-12-01), Grainger et al.
patent: 5249919 (1993-10-01), Sishtla et al.
patent: 5457291 (1995-10-01), Richardson
patent: 5644918 (1997-07-01), Gulati et al.
patent: 5919029 (1999-07-01), Van Nostrand et al.
patent: 5923003 (1999-07-01), Arcas et al.
patent: 5979593 (1999-11-01), Rice et al.
patent: 6082489 (2000-07-01), Iwao et al.
patent: 6135238 (2000-10-01), Arcas et al.
patent: 6290022 (2001-09-01), Wolf et al.
patent: 6309176 (2001-10-01), Periyathamby et al.
International Searching Authority, Patent Cooperation Treaty, Notification of Transmittal of The International Search Report or the Declaration, International Application No. PCT/US01/02984, Apr. 27, 2001, 6 pages.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Acoustic liner and a fluid pressurizing device and method... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Acoustic liner and a fluid pressurizing device and method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acoustic liner and a fluid pressurizing device and method... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3005154

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.