Spark Arrestor Mesh

[SilentPartner]

Has anyone tried using spark arrestor mesh in line with their vacuum to eliminate sparks?

 

[Stacy E. Apelt - Bladesmith]

It will work as long as it does not get clogged with grinding debris ... but therein lies the rub.

I have a coarse mesh on the receiver funnel. A spark trap is the best method of eliminating both the heavy dust and sparks from getting in the vac lines.

 

[SilentPartner]

It will work as long as it does not get clogged with grinding debris ... but therein lies the rub.

I have a coarse mesh on the receiver funnel. A spark trap is the best method of eliminating both the heavy dust and sparks from getting in the vac lines.

Thanks Stacey. Do you need to be constantly cleaning out the course mesh? What percentage of the sparks does it kill?

 

[Stacy E. Apelt - Bladesmith]

spark trap is just some sort of pressure drop separator to let the heavier particles fall into a container with some water in it. One method is to use a metal dust deputy on top of a metal container/drum:

Heavy-Duty Steel Dust Deputy DIY Cyclone Separator | Oneida Air Systems

Pre-separates airborne dust and debris to prevent vacuum filter clogging. Full-welded heavy gauge steel for industrial applications such as concrete grinding and other abrasive materials. Assists with OSHA compliance for new silica dust safety standards. Includes cyclone, hose adapters, gasket...

www.oneida-air.com

Others have made a separator with a baffle down the center.

 

[SilentPartner]

My goal is to stay away from a system that uses water so that I can keep the environment as clean and low maintenance as possible. And obviously keep it safe.

It seems that the sparks have a very small mass. I'm wondering with a 4" dust collection tube if after 20' of travel and lots of air volume of there could be any spark left? But after 20+ feet it if went through a dust deputy would it then be safe to direct vent it out of my shop?

I've also been looking at spark arrestors used in tractors. They are a lot less expensive than one used for a commercial vacuum. But my first thought was that they are meant to be run at very high temperatures off a diesel engine. And while diesel fumes are certainly not clean they are probably smaller and cleaner than metal shavings.

 

[Stacy E. Apelt - Bladesmith]

The issue in most shops is that you grind both steel and wood. If you have separate systems, then you could easily use a long duct or spark arrestor screens. A dust deputy with no water will work l, but an inch of water is a good extra. I don't see how this would be unfriendly to the environment. It makes te system work better.

The problem with sparks lies in the debris that builds up in the catch tray, ducts, and other places in the vacuum system. Steel dust will catch fire from sparks and burn like steel wool. Wood dust can easily ignite and smolder for a long time.

Making the duct extra-long is not necessarily a solution. Pressure drop and conduit flow resistance will lower the efficiency as length increases.

Some questions:
What size vacuum system are you using? (HP, CFM, etc.)
How are you catching the grinding dust and sparks? (catch funnel/pan/etc.)
Do you do wood with the same system?
Are there multiple grinders on the system?

 

[SilentPartner]

Thanks, Stacey. I get that there isn't a simple solution.

I have a central dust evacuation system for wood. I think I will have a gate to my my funnel/pan that I can open only when I'm using the grinder for wood and the rest of the time it will just go to the pan unassisted by a vacuum. The only caveat would be to never use the grinder for wood immediately after grinding metal.