Dust Sniper (quiet extractor system)

Step 10 The Outer part 3 - The Forbidden Cork Forest (or Air Intake Sound Proofing)

Unfortunately, despite the sound having to travel against the airflow created by the vacuums, the gaps needed for the air to come in will still leak a lot of sound.  As MahavishnuMan told me when I foolishly suggested the sound might be reduced by the inrushing air:    

"...in order to "suck up the sound", your vacuum would have to breathe in air at a higher velocity than what sound travels, which is 1,127 ft/sec at sea level and standard temperature and air pressure. Not only am I positive your vacuum doesn't suck at Mach 1, but if it did you would have a sonic boom loud enough to crack the box."

So yeah, we need to 'treat' the air inlets so that we defeat the escaping sound. For this purpose I am experimenting with what I fondly dub the 'Forbidden Cork Forest'.  It is crucial that we don't add much to the air resistance, which is tricky when you are introducing obstacles to block sound.  

The idea with the cork forest is that it will block sound with the sound absorbing 'trees' (the corks), while still presenting a smooth round aerodynamic surface for the air to pass through with minimal turbulence.
 

Comments

[mcr2582]

Amazingly detailed how-to! I wanted to share a similar "sound crystal" solution I used for my air compressor sound box. I used metal pipe, but I really like the cork idea!

http://www.artifacturestudios.com/blog/archives/985