SILENCER Russian patent published in 2002 - IPC

FIELD: air ducts of air heating systems, ventilation and air-conditioning systems. SUBSTANCE: sound-absorbing members 2 are arranged in rectangular 1 made from zinc-coated steel. Each sound-absorbing member 2 is provided with at least one baffle 3 made in form of dihedral angle to enhanced noise absorbing. Interior of this angle is located on side of inlet of sound waves and outer surfaces of its faces are directed towards air passages. According to one version, sound-absorbing members are made in form of rectangular parallelepiped (Fig. 1). Sound- absorbing members 2 are streamlined bodies manufactured from profiled perforated pipe 7 made in its turn from coated-coated steel for additional reduction of noise through reduction of its high- frequency component. This pipe has elliptical shape (Fig. ) in one case and tear-shaped form in other case (Fig. ). Arranged in housing 1 are two rows of sound-absorbing members 2 of elliptical profile (Fig. 2) which are extended across flow forming air passages between them. Sound-absorbing members 2 of second row are shifted relative to sound-absorbing members of first row. High degree of noise absorbing is obtained when sound-absorbing members have tear-shaped profile (Fig. ) and three rows of sound- absorbing members are mounted in silencer housing 1. Result of noise absorbing is enhanced when sound-absorbing members 2 of each subsequent row are not only shifted relative to sound- absorbing members of previous row but overlap passages between them. EFFECT: enhanced efficiency of noise absorbing. 9 cl, 3 dwg