JPH0684860B

• Main Authors: NAKANISHI KEIJI, SUGAWARA MASAMICHI, SEKIGUCHI YASUYUKI
• Format: Patent
• Language: English
• Published: 26.10.1994
• Edition: 5
• Subjects: ACOUSTICS; ACOUSTICS NOT OTHERWISE PROVIDED FOR; BLASTING; COLD ROOMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; COOLING OR FREEZING APPARATUS NOT COVERED BY ANY OTHERSUBCLASS; HEAT PUMP SYSTEMS; HEATING; ICE-BOXES; LIGHTING; LIQUEFACTION SOLIDIFICATION OF GASES; MANUFACTURE OR STORAGE OF ICE; MECHANICAL ENGINEERING; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING,NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; MUSICAL INSTRUMENTS; PHYSICS; REFRIGERATION OR COOLING; REFRIGERATORS; SOUND-PRODUCING DEVICES; WEAPONS

A silencer attenuating a noise from a noise source to be ventilated of this invention comprises a machine compartment with a one-dimensional duct configuration whose sectional dimension is sufficiently small in comparison with the wavelength of the noise to be attenuated, a compressor and/or other machinery disposed within the machine compartment, an opening for dissipation of heat as disposed in a wall of the machine compartment and opening in a direction generally perpendicular to the direction of advance of sound within the machine compartment, a vibration pickup for detecting the vibration of the machinery corresponding to the output noise of the machinery, and a control circuit for processing output signals from the vibration pickup to drive a sound generator such as a speaker. The sound generator outputs a controlling signal dependent on the machine noise to cancel the noise about to emerge from the machine compartment.