Measuring Air Born Silica Dust

[liambesaw]

9 minutes ago, neilestrick said:

Would it be possible to modify a wood shop dust collection system? Can you get a HEPA filter on those? Or would just having the collection container be outside the studio or contained in a closet or something like that be sufficient?

Ours is not filtered beyond some large electrostatic baffles inside the unit designed to protect the impeller itself.  It exhausts outdoors for that reason.

[Bill Kielb]

28 minutes ago, neilestrick said:

Would it be possible to modify a wood shop dust collection system? Can you get a HEPA filter on those? Or would just having the collection container be outside the studio or contained in a closet or something like that be sufficient?

Discharge outside (responsibly) would be fine, this can be hepa filtered as well but then requires significant maintenance and more horsepower. Hepa filters on vacuums so the particles don’t get discharged back into the studio.
The hybrid is the central vac that collects and discharges to outdoors which is sort of the economy method. It allows the collection into a plastic bag for easy removal and discard. So in the case of central vac, collection indoors with discharge outside

wood dust collectors generally have greater design velocity to trap heavier particles and designed to resist explosion. In theory they would likely work well as long as they discharge outdoors appropriately and can be emptied reasonably.

[Mark C.]

Mine is a delta woodshop filter modified with hepa filter in the glaze room-buts it not a spot location filter

(would it be possible to modify a wood shop dust collection system? Can you get a HEPA filter on those? )

[Min]

@Bill Kielb, thanks for the extra image, absolutely agreed it's always a very good thing to be vigilant with silica dust.

The reason I asked about the before and after shot was to see what the ambient dust particle load looked like prior to scooping silica, ie the variables being controlled as much as possible. Visual comparison of pre and post with the same light path and background etc.  

[Bill Kielb]

1 hour ago, Min said:

The reason I asked about the before and after shot was to see what the ambient dust particle load looked like prior to scooping silica, ie the variables being controlled as much as possible

Yes I assumed you were looking for that. Using video is super helpful for a visual comparative idea as the moments in time become apparent. The conclusion: it’s near impossible to scoop gently and not eject a whole bunch. Proper use of an extractor arm during this process dramatically improves the situation.

[Bill Kielb]

3 hours ago, Mark C. said:

would it be possible to modify a wood shop dust collection system? Can you get a HEPA filter on those? )

Hepa filters do not necessarily make a product a hepa rated assembly. The filter media, carrier,  filter assembly must remove 99.97% of particles down to 0.3 microns  (From memory) I believe so they test the designed product. In the case of a vacuum particles 0.3 microns or  greater must be trapped from returning to the space under pretty high design velocity to filter area ratios.

Using a Hepa rated filter is truly better than a standard filter but to certify equipment a bit more engineering is really necessary to prove it will remain as such in operation. So that is the caution, using a rated filter in a non rated device does not make it Hepa rated.

It is possible though, just realistic caution is in order since if it does not function it will quickly pollute the area it is serving. Exhausting this outdoors minimizes this risk, but again if exhausted using ductwork, the ductwork will be pressurized which for 0.3 micron leakage is an important design consideration to be aware of. Ordinary ductwork even with taped seams is probably not gonna cut it.

Just some food for thought, but is possible.

I should mention, it sounds as if you have yours hooked up as an air scrubber which could be good but also if leaky be capable of discharging things around the room at high velocity - potentially, not good.

[Hulk]

Measuring exposure, likely to take second seat behind strategies to reduce exposure, aye. That said, the amount of dust accumulating on a clean flat surface gives an indication, eh? For example, in our home, there's more dust near the floor than at waist level, more dust at waist level than at eye level, more dust generated by clothing (both fabric particles and fibers and [ew!] skin particles) than just about anything else, excepting open windows on the ocean/breeze side o' th' house, and perhaps baking with flour.

In the studio, dry clay, any dry clay - but particularly clay on the floor - produces dust. After the floor, clay bags and wedging seem to produce the most dust (in my studio)...

Hence, frequent wet mop of the floor, wet wipe down of wedging area, wet wipe inside and outside of clay bags (limit the dry filmy bits) seems to help quite a bit, also not opening doors/windows to the outside except after cleaning (limit air movement), and generally limiting dry clay (any - on tools, wheel, rags, clothing, any!).The dust that accumulates on shelving (lots of shelves in my studio) tell a story ...as do undisturbed flat surfaces in other's studios (yuck!). Try cleaning a square of high shelf somewhere in your local community type studio and check back the next day.

[Mark C.]

Yes Bill its air scrubber. Calt dist is best handled wet if possible -mops and mist but thats not the treakl world for many so something is better than nothing. You are right about leaks blowing it around I tape all air leaks before they happen  in my scrubber. The hepa is taped onto 3 other filters air tight on the intake.

No matter what you choose something is better than nothing,

[liambesaw]

Our big vac system is all 4 inch ABS sewer pipe.  We had metal ducting at one point but with all of the suction ports closed it would occasionally suck the metal ducting apart.  The problem with our ABS is that we use a lot of organic solvents at work and they make it brittle over time.  Luckily it's easy to replace a section when this happens.

Mmmm methyl methylacrylate, a smell you will never forget lol

[Bill Kielb]

3 hours ago, liambesaw said:

Our big vac system is all 4 inch ABS sewer pipe.  We had metal ducting at one point but with all of the suction ports closed it would occasionally suck the metal ducting apart

An ideal candidate for variable speed drive and managed static pressure. Save horsepower, save carbon, save the planet! Providing sufficient airflow to cool the motor, etc.... which could be managed suction  bypass Reset by static and temperature and just save the motor. In other words waste power, not really saving the planet. Initial ductwork design too thin btw, these are all known design issues. Maybe not a real design or someone forgot to balance. Oops! Horsepower varies with the square of SP. missed opportunity!

[liambesaw]

2 hours ago, Bill Kielb said:

An ideal candidate for variable speed drive and managed static pressure. Save horsepower, save carbon, save the planet! Providing sufficient airflow to cool the motor, etc.... which could be managed suction  bypass Reset by static and temperature and just save the motor. In other words waste power, not really saving the planet. Initial ductwork design too thin btw, these are all known design issues. Maybe not a real design or someone forgot to balance. Oops! Horsepower varies with the square of SP. missed opportunity!

Not a designed system, it's diy.  We turn it off when not in use