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This is neat. It's an air gun that uses a design almost like an aerospike nozzle on a rocket engine. Air is injected in a ring around the conical center. Apparently it's relatively quiet. I just ordered one. We shall see.
https://www.youtube.com/watch?v=HZDspWr687o
High flow, low pressure air nozzles are one of few benefits of worker safety initiatives.
The aerospike is a good analogy, the effect is generated by venturi and eductor physics.
Here is one version.
https://www.google.com/url?sa=t&rct=...MErDz_PVDfQlrw
93 Decibels!! . . . ain't all that quiet. :rimshot:
Looks like at 93 dBa it just meets OSHA standards. Thanks for the info.
Here's what OSHA has to say, charts, too: https://www.osha.gov/otm/section-3-h...ards/chapter-5
Thanks for the link to the 500 page government document! No page numbers and it is not a PDF so I am only guessing at the page count. LOL
Following is a heavy edit of one section in the interesting document. Obviously, I have removed copious verbiage to point to relevant values. I have bolded and underlined for the speed readers on here. :)
- Brief History of Occupational Noise Standards
The Occupational Safety and Health Act (OSH Act) of 1970 built upon earlier attempts in the United States to regulate noise hazards associated with occupational hearing loss.
. . . This set an 8-hour TWA of 90 dBA and a 5-dBA exchange rate for any company with a federal contract worth more than $10,000. . . . .The same 8-hour TWA and exchange rate are still used by OSHA today.
. . . in 1972, NIOSH published recommendations for an OSHA occupational noise standard, which included a recommended 8-hour TWA exposure limit of 85 dBA and a 5-dBA exchange rate. However, in 1973, OSHA's Standards Advisory Committee maintained the 90-dBA 8-hour TWA with a 5-dBA exchange rate.
. . . In 1974, OSHA published a proposed occupational noise standard, which included a requirement for employers to provide a hearing conservation program for workers exposed to an 8-hour TWA of 85 dBA or more.
. . . This provision was adopted as part of the amendments of 1981 and 1983. The 8-hour TWA for OSHA's noise standard remained at 90 dBA with a 5-dBA exchange rate and included a requirement for a hearing conservation program for workers exposed to an 8-hour TWA of at least 85 dBA.
The referenced document was published in 2013. AFAIK, these levels still exist today.
Maybe this one is something new, but I doubt its anymore effective than a 6.5 hp shop vac is at sucking away swarth through a wand with a 1/2x1" orifice. At least with the vac the crap is gone and not becoming flying debris in the air to find its way behind my safety glasses. Which brings up a couple more things on my eccentrically slanted mind. Most of the time that I need a blow gun is for clearing minute particles out of ports, pathways and orifices in things such as hydraulic valves, tubing or carburetors. I find that neoprene tipped guns are the only thing which will do the job properly. any other time I want or need a blow gun I reach for my gun that has a 2 ft long 1/4" diameter wand. non restricted end. When it comes to safety glasses the only times I have ever gotten anything in my eyes has been while wearing safety glasses, and once it happened while wearing both safety glasses and a face shield. It was probably a freak event but a supervisor saw it happen and was the one to drove me to the emergency eye clinic to have the particle extracted, also the one and only time I have ever been in one of those places as well.
So I ordered one and it arrived. It's kinda weird. It seems a bit quieter. Not enough to matter though. What I'm impressed with is the amount of air it moves. This is a very subjective analysis, but it feels like it moves about 3x as much air as a normal blow gun. It's crazy. I have a theory about this. I think the "aerospike" style nozzle is functioning similar to a jet pump, or an air multiplier.
Anyway I'm happy with it. More of a shop oddity to show my friends than anything, but I'll certainly use it.
Gaurdair makes one with 4 nozzles called the QuietForce Air Gun, Cluster Nozzle, 82 dB. The thing is according to the stats it consumes 56CFM but still has a 1/4 FNPT inlet, That's a lot of air for such a small inlet connectionQuote:
Originally Posted by nova_robotics
https://www.zoro.com/guardair-quietf...All%20Products
It looks like a prop from a Star Trek movie.Quote:
Originally Posted by Frank S
Added volume is siphoned from air surrounding base of each nozzle, several 'vents' intake (like a venturi in carburetor) at those low pressure areas.
The normal OSHA deadhead nozzle with larger holes can demonstrate it. Light and extinguish a match, holding back from exit airstream, near the holes. Sucks right in.
I use this style of blow gun. The venturi really increases the power so much it will suck your air tank dry. I've had the shorter one since 1977. It was longer but it broke a few times and I had to rethread the end. Sound level is 114 decibels, ear protection is recommended...
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