Diffusion muffling device, diffusion resonance muffling device, full-frequency diffusion muffling device, muffling system for ventilation channel, and muffling method using the same

A diffusion resonance muffling device, which is applicable to a ventilation channel, the diffusion resonance muffling device comprising:

• a plurality of diffusion resonance muffling units disposed in a ventilation extension direction of the ventilation channel, wherein the plurality of diffusion resonance muffling units are arranged in parallel in a direction with a predetermined angle between the direction and the ventilation extension direction of the ventilation channel, a muffling passage is formed between each two adjacent diffusion resonance muffling units, wherein each of the diffusion resonance muffling units comprises at least one diffusion resonance structure, each of the at least one diffusion resonance structure comprising:
• a plurality of first convex portions and a plurality of second convex portions which are disposed opposite to each other;
• each of the first convex portions is spliced with a corresponding second convex portion to form a corresponding cavity;
• and
• when sound waves enter the muffling passage, the sound waves are diffused and reflected for multiple times in the muffling passage by the plurality of first convex portions and the plurality of second convex portions and are resonantly absorbed by each of the cavities and then the sound is attenuated,
• the diffusion resonance muffling device further comprises fixing structures configured to fix the plurality of diffusion resonance muffling units arranged in parallel to the ventilation channel, wherein each fixing structure comprises a fixed rectangular tube, angle steels which are disposed on the fixed rectangular tube and configured to fix all the respective diffusion resonance muffling units to the fixed rectangular tube, and expansion bolts which are disposed at both ends of the fixed rectangular tube and configured to be fixed to both sides of the ventilation channel.

A full-frequency diffusion muffling device, which is applicable to a ventilation channel, the full-frequency diffusion muffling device comprising:

• a plurality of full-frequency diffusion muffling units disposed in a ventilation extension direction of the ventilation channel, wherein the plurality of full-frequency diffusion resonance muffling units are arranged in parallel in a direction with a predetermined angle between the direction and the ventilation extension direction of the ventilation channel, and a muffling passage is formed between each two adjacent full-frequency diffusion resonance muffling units;
• each of the full-frequency diffusion muffling units comprises at least one full-frequency diffusion muffling structure, each of the at least one full-frequency diffusion muffling structure comprising:
• a first perforated metal plate;
• a second perforated metal plate;
• a plurality of first convex portions and a plurality of second convex portions which are disposed opposite to each other and are disposed between the first perforated metal plate and the second perforated metal plate, each of the first convex portions is spliced with a corresponding second convex portion to form a corresponding cavity;
• and
• a porous sound absorbing material filled in a region between the first convex portions and the first perforated metal plate and in a region between the second convex portions and the second perforated metal plate;
• when sound waves enter the muffling passage, high-frequency sound is muffled by the porous sound absorbing material after the sound waves sequentially pass through the first perforated metal plate and the second perforated metal plate, and then the sound waves are diffused and reflected for multiple times in the muffling passage by the plurality of first convex portions and the plurality of second convex portions and are resonantly absorbed by each of the cavities and then the sound is attenuated.