I was told we were trying to do the vent design and install ourselves but couldn’t find anyone willing to stamp off on the designs. I have a good friend who is an HVAC engineer and architect I reached out to him. He has put me in contact with a good buddy of his who has an active stamp and is willing to help. Who is working on this?
Alex Rhodes has an engineer’s plans and is working w/ the city.
We might still want to go with the water table conversion, especially if the vent has to have a filter. So maybe it wouldn’t hurt to ask if that would be enough on its own. Although a hood would be nice for welding too. The claim would be that the torch nozzle is blowing almost all of the fumes and particulate directly into the water to capture it, just like an oil bath filter on an engine. Actually they use to use water baths. Lots of people have done it on plasma cam machines.
I am confused here…
Do you realize there is a water table on plasma cutter already?
Also to reiterate the FM specifically wants all plasma fumes vented outside.
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Maybe he means the other kind of water table (submerged).
You see there are 2 kind of water table
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Unsubmerged, where the level of the water is slightly below the metal being cut or
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Submerged, where the metal being cut is either partially or fully submerged.
Generally for the second kind you need a special torch that is made to get wet. Also the second kind captures more of the soot and smoke created and usually has an air bladder inside the water tank that can raise and lower the water level quickly to making part finding much easier after the cutting is done.
I’ve installed a few of the second kind of plasmas when I worked for Multicam. They work pretty well at capturing fumes, but are much more expensive and messy in their own way.
Thanks,
Alyssa
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This has been kicked around the block a few times, so I don’t know where we currently have landed (as far as the “official” plan Alex is working with).
However, I do remember these points, so I’ll sling 'em back out here. If you dig hard enough, I’m sure you can find them here somewhere.
The current setup is to have water sitting under the workpiece. I think it was drained off due to rust out concerns of the tank (tub?). Also due to inactivity, standing water concerns.
The idea was considered to convert the water table to fume collection, more or less downdraft style, with no water.
There was also mentioned some concern about contaminated water and what to do with it. The idea presented was that it might not be acceptable to dump the water from a water table (either style, one would presume) down the drain since it would contain “heavy metals” (the degree to which the metals are heavy, any of it might be regulated, or actually a concern being points of contention). The discussed conversion to downdraft would address this concern as well, as water would no longer be used.
There was also talk that we would keep the water table design, presuming that the water issue would be a non-concern or self-resolving, and move to a updraft extractor style fume hood. Then the water would be under the workpiece as originally designed and the extractor would remove airborne contaminates to the out-of-doors. I do not recall talk of rust-through mitigation on the water tank.
As stated, I have no idea where we have landed after all this talk.
Since my firm designed the proposed solution being submitted to the fire marshal I feel I can speak to this issue… The current proposal is a downdraft vent attached to the bed of the plasma cam, per plasma cam manufacturer recommendations. It will remove 3000 ft.³ of air per minute. If a filter is desired in the future there is a chance it could be added later, but is not part of the current proposal.
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This is one of those posts you wish you could like more than once.
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Do we have any progress on this? What has been done so far?
Last Thursday we got approval on the drawing from the city on the drawings we had. We have asked the landlord to install a 12" hole, waiting on that response. I am now looking into a Mechanical Contractor, so if you have any suggestions or contacts pleas PM me.
Thanks,
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Square or round hole? Roof or Wall?
Round hole. Roof. 20 characters.
Great work, Alex, getting the ball rolling again on the CNC Plasma ventilation!
Per the BoD meeting notes:
CNC Plasma cutter Ventilation solution (Alex Rhodes)
- Luke Olson moved to pass the motion as “Allocate $5000 from router loan fund and $6000 from the general fund to metal shop for the purpose of installing ventilation for the CNC plasma cutter”, seconded by Robert Davis
- Motion passed with 4 in favor, 1 opposed
I’m looking forward to seeing this super-cool tool back in action.
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Wow, $11,000? Anyways, I support getting the CNC plasma cutter running so I can get some training on welding 
Just curious - but how long is the lease and are there any plans on renewing the lease ?
11 Grand for a glorified fart fan in a space that has a short term lease?
About 16 more months in current lease, no discussion I know of on future plans yet
Thank you!
This guy has a nifty dust/particle containment unit for his cnc Plasma table
Yeah we had to have engineered drawings to pease the damn inspector/Fire Marshall/code enforcement.
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