Spark arrester for grinding table

[QSIMDO]

I have a down draft table and dust collector from back when I worked on that soft metal called wood.
Make a darn nice location for my bench grinder but I certainly don't want to torch my house either.
Anyway to kill sparks before they get to the dust collector about 10' away?

[Tobias-B]

I'm thinking of those old water bath air cleaners on agricultural stationary engines...

Steam trains used mesh screens in their stacks to catch the chunks before they
burned down the entire old west...

t

[BCRider]

Other than making sure there's no wood dust in it any more?

Look at how far the sparks from metal are lit up. It's rare to throw them even 10 ft. And then typically only from a disc grinder.

Still, there are cyclonic and water bath inline separators you might want to look into. While the sparks and particles might well be cooled off if you were to use a slightly longer duct run there's still the issue of surface erosion in the fan from all that hard dust and some grinding stone. A cyclonic or water bath separator would trap the lion's share before it gets to the actual fan to do damage.

There's lots of designs to be found on the webz for both. Both to make and to buy. Obviously you'll need to substitute metal in place of the frequently used plastic items though. At least for the portions that will see the glowing sparks.

Other than metal vs wood and sparky hard dust vs soft wood dust the designs should work out fairly comparably other than choosing the right material to make the separators from to avoid melting, fire or early sandblasted holes in the parts.

[Paul Alciatore]

Metal duct for the 10 or more feet and a sprinkler system in the dust collector. They make double wall duct for gas water heater vents: you might consider using that. A fire inside of that duct is probably going no where. But pay attention to what could happen at the ends of the run.

Sorry, that's all I can come up with.

[JoeLee]

Metal duct for the 10 or more feet and a sprinkler system in the dust collector. They make double wall duct for gas water heater vents: you might consider using that. A fire inside of that duct is probably going no where. But pay attention to what could happen at the ends of the run.

Sorry, that's all I can come up with.

You could put a diffuser in the duct like the ones used in the hot water tank.

JL......

[boslab]

Spark box, metal box that has a labarynth of alternating plates the airflow must travel through, about an inch gap, like a maze , these have been around for a long time in one form or another, imagine getting a pack of cards, splitting the pack and fanning back together. | |||||||||||||. Left right left right, there were 12 plates in the spark arrestors in work, the lid of the box was removable, silicone rubber gasket, 6” pipe in 6” out, hose from linisher was a metal flex, after was 6” spiral reinforced.
these fed into a DMC pulse aka Donaldson torrit, quite a good set up as it was inside a met lab, worked well, the spark arresting chamber was a dmc product
these work too

https://www.ducting-express.co.uk/product/spark-trap-300-diameter?gclid=Cj0KCQjwjbyYBhCdARIsAArC6LKAM8ulvjWTXHXXbqAQs-kuq3Fd_LwPOGmYHgWVh7wwbDm-i_ivdZIaAvC-EALw_wcB

mark

[epicfail48]

Water bucket separator perhaps? Bucket of water about halfway full, line running from the top of the bucket above the waterline to the collector, intake line below the waterline. Anything that comes in from the grinder has to go through the water to even have a chance of getting over to the collector itself. Just use a short, metallic hose like a dryer hose for the run between the separator and the grinder. Unless youre grinding magnesium, shouldnt ever have a spark make it to the flammable stuff

[Bob Engelhardt]

[...]
Anyway to kill sparks before they get to the dust collector about 10' away?

You already have a completely efficient spark killer in the 10' of pipe. Unless you're making sparks the size of a pea, no spark is going to stay hot for 10' in that fast moving air.

On another note, grinder dust is way more dense than wood dust & I suspect that most of it will not reach the collector, but will settle on the pipe.

[reggie_obe]

Metal duct for the 10 or more feet and a sprinkler system in the dust collector. They make double wall duct for gas water heater vents: you might consider using that. A fire inside of that duct is probably going no where. But pay attention to what could happen at the ends of the run.

Sorry, that's all I can come up with.

That's called :"B" pipe and not intended for vacuum. Vacuum piping has a spiral seam.

[QSIMDO]

The vision of a wire mesh kitchen strainer popped into my head.
I could install one over the table outlet (6") as a sort of spark arrester.
The down draft table is built like a torsion box so I have 2.5" height inside...maybe a labyrinth!
My bench grinder to be placed on the table is only used for tool sharpening with 2, 8" CBN wheels so there's not a huge spark array.
I built a 4" wide belt sander for all the dramatic video spark effects.