▎ 摘　　要

NOVELTY - Multi-frequency selective noise reduction device comprises an inner layer noise reduction unit (1) set close to one side of the noise source. The inner layer substrate (11) is a micro-perforated plate. An inner coating layer is bonded on the inner layer substrates. An internal sound insulation layer (14) is made of porous sound insulation material. A vacuum outer framework is provided on the vacuum noise reduction units (2). The vacuum outer scaffold is supported on the panel of the inner sound insulating layer through a first vibration reduction connecting piece (21) to form a sealed vacuum layer. The thermal conducting piece is provided between the thermal conducting piece and the sealed vacuum wall. USE - The multi-frequency selective noise reduction device is useful in industrial noise control technology field, chemical enterprise spot compressor steam turbine and other moving device. ADVANTAGE - The device effectively isolates complex industrial noise in high and middle frequency, and middle and low frequency bands, solves ventilation and thermal dissipation problem of the high temperature device pipeline, has simple structure and good commonality, effectively blocks middle-high frequency noise, prevents sound transmission of the full frequency range, has good barrier effect on the low and high full frequency band noise and radiating effect, and good sound insulation and noise reduction effect for the high noise industrial environment. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of multi-frequency selective noise reduction device. Inner layer noise reduction unit (1) Vacuum noise reduction unit (2) Outer noise reduction unit (3) Inner layer substrate (11) Inner cladding layer (12) Inner sound-absorbing layer (13) Inner sound insulation layer (14) First vibration reduction connecting piece (21) Vacuum layer (22) Heat conducting communication piece (23) Vacuum outer frame (24) Second vibration reduction connecting piece (31) Air layer (32) Outer layer substrate (33) Outer coating (34) Outer sound-absorbing layer (35) Outer sound insulation layer (36) Vacuum gauge (221) Vacuum valve (222) Thermometer (321)