Low-noise fume extractor hood

摘要

A fume extractor hood is disclosed, comprising a box with a motor-fan assembly and a muffler module comprising a bearing frame defining an air extraction conduit with axis (A), an active noise suppression system comprising at least one electro-acoustic transducer and at least two microphones, a passive noise suppression system comprising a sound absorbent material. Said muffler module comprises at least two electro-acoustic transducers connected to the walls of said bearing frame, in opposite positions, in such manner to leave the central part of said conduit free. The sound beams coming from said at least two electro-acoustic transducers are mutually combined, obtaining a resulting sound beam that can be directed towards a preferred direction by means of beam forming algorithms.

主权项

1. A fume extractor hood comprising:
a box containing a motor-fan assembly comprising a motor that actuates at least one fan, and a muffler module disposed under said box, said muffler module comprising:
a bearing frame defining an air extractor conduit with an axis;an active noise suppression system comprising at least two electroacoustic transducers and at least two microphones connected to a control unit; anda passive noise suppression system comprising a sound absorbent material disposed between said at least two microphones, wherein said at least two electroacoustic transducers are connected to walls of said bearing frame in opposite positions with respect the axis of said air extractor conduit in such manner to leave a central part of said air extractor conduit free, wherein each electroacoustic transducer of said at least two electroacoustic transducers having a sound emission surface inclined by an angle greater than 0° with respect to the axis of said air extractor conduit to generate sound beams with an axis inclined by an angle less than 90° with respect to the axis of said air extractor conduit in such manner that the sound beams coming from the electroacoustic transducers are mutually combined so as to obtain a resulting sound beam directed in a desired direction by a beam forming algorithm.