Dry acoustic system preventing condensation
AssigneeDigisonix, Inc.
InventorsSeth D. Goodman, Richard A. Hoffmann
Life of this patent
Estimating the term…
Abstract
An active noise control system is provided for cancellation of noise in a duct. A speaker is mounted over an opening in the duct. An enclosure is mounted the duct about the speaker. Air flow is generated through the enclosure in order to balance the diffusion of water vapor through the speaker such that the dew point of the air in the enclosure is always below the temperature of the air in the enclosure, thus avoiding condensation.
Claims29
An acoustic system comprising:
- a duct defining a transmission path for an acoustic wave;
- an acoustic transducer operating over a range of operating frequencies and mounted to interact with said acoustic wave through an opening in said duct;
- a transducer enclosure having an interior containing said transducer;
- a first acoustic element providing an air flow path communicating with said interior of said enclosure through a hole in the enclosure, said first element having a high restriction to air flow and a high acoustic impedance at the operating frequencies of said transducer;
- and
- a second acoustic element providing an air flow path communicating with said interior of said enclosure through a hole in the duct, said second element having a low restriction to air flow and a high acoustic impedance at the operating frequencies of said transducer.
An acoustic system comprising a duct defining a transmission path for an acoustic wave, an acoustic transducer operating over a range of operating frequencies and mounted in relation to said duct so that said transducer interacts with said acoustic wave through an opening in said duct, a transducer enclosure having an interior containing said transducer, and air flow means for providing a steady flow of air through the interior of said enclosure sufficient to balance diffusion of water vapor into the interior of said enclosure such that the dew point of air in said enclosure is below the temperature of air in the interior of said enclosure, to avoid condensation in the interior of the enclosure.
An acoustic system comprising a duct defining a transmission path for an acoustic wave, an acoustic transducer interacting with said acoustic wave through an opening in said duct, a membrane located over the opening, a separation chamber between the membrane and the acoustic transducer, a transducer enclosure having an interior containing said transducer, and an air flow structure maintaining a steady flow of air through said interior of said enclosure and through said separation chamber sufficient to balance diffusion of water vapor into said chamber and into said enclosure.
In an active acoustic attenuation system for attenuating an acoustic wave propagating in the interior of a duct a transducer enclosure drier system comprising:
- an enclosure having an interior;
- an acoustic transducer located within the interior of the enclosure that interacts with the acoustic wave through an opening in the duct;
- an air inlet to the enclosure;
- means for providing dry compressed air into the enclosure through the air inlet;
- means for controlling the flow rate of the dry compressed air into the enclosure;
- and
- means for equalizing the pressure between the interior of the enclosure and the interior of the duct.
An active noise control system for a duct comprising:
- an enclosure affixable to the duct;
- an acoustic transducer within an interior of the enclosure, the acoustic transducer interacting with an acoustic wave propagating in the duct through an opening in the duct;
- an air inlet to the enclosure that provides air into the interior of the enclosure;
- an air outlet from the enclosure;
- a vacuum source that draws air out of the enclosure through the air outlet;
- and
- means for controlling the flow rate of the air drawn from the enclosure by the vacuum source.
Dependencies are inferred from the claim text.