Title:
ROTARY THROAT CUTOFF DEVICE AND METHOD FOR REDUCING CENTRIFUGAL FAN NOISE
Document Type and Number:
Japanese Patent JP2628145
Kind Code:
B2
Abstract:
PURPOSE: To reduce noise pulsation generated in a fan by providing a cylindrical rotor having a plurality of resonator cavities having various depths and rotating this in a casing to absorb sound pulses generated by the rotation of a fan impeller.
CONSTITUTION: In a centrifugal fan assembly including a housing containing an impeller 22 equipped with a blade and placed on a rotary shaft, a rotary throat cutoff sound resonator 25 is attached to the housing 21 of the centrifugal fan assembly around the impeller 22 and near a discharge opening 29. This resonator 25 includes a partially downward casing 26 enveloping a part of a thin, long and cylindrical rotor 30. The rotor 30 includes a plurality of resonance cavities extended in a direction crossing a rotor axis and having various depths, supported in both ends rotatably by a bearing, driven by a transmission motor via a driving means such as a belt or a pulley, and thus noise pulsation generated by the fan 20 is suppressed.
Inventors:
Frantisek El Eisinger
Application Number:
JP16913494A
Publication Date:
July 09, 1997
Filing Date:
July 21, 1994
Export Citation:
Assignee:
FOSTER WHEELER ENERGY CORPORTION
International Classes:
F01N1/02; F04B39/00; F04D17/08; F04D25/08; F04D29/42; F04D29/66; (IPC1-7): F04D29/66
Domestic Patent References:
| JP481594A | ||||
| JP450498A |
Attorney, Agent or Firm:
Sakai Hajime