Re: AM dust filters

[Jason Lixfeld <jason () lixfeld ca>]

On Aug 12, 2014, at 3:22 PM, Doug Barton <dougb () dougbarton us> wrote:

> On 08/12/2014 11:19 AM, Jason Lixfeld wrote:
> > Hi,
> >
> > I'm interested in knowing what sorts of material folks use to make after-market dust filters for their various 
> > devices which wouldn't normally have any.  This seems to almost be a necessity when these kinds of devices are 
> > deployed in environments that are overly dusty and dirty (it should also be implied that these environments are all 
> > in-doors and would have less than ideal airflow and climate control).
> >
> > A material that is too dense will hider airflow and cause an immediate increase in inlet temperature, which would 
> > exacerbate a potentially threatening temperature situation in environments where the ambient temperature is already 
> > in the mid to high twenties and above (that's 77 - 86F+ for my American friends ;)).  A material that is not dense 
> > enough won't do a very good job at filtering.
> >
> > Do folks just hack up HEPA filters or something?
>
> It sort of depends on what kind of stuff you're trying to filter out.

Small-ish stuff.  Your every day, run of the mill fine grain dust, tracked-in dirt & sand, some construction 
particulate (metal shavings, etc).

> Panty hose actually makes a reasonably good filter for larger stuff, but Tom's question about how often are you going 
> to service it comes into play, since you need to remove the debris that it catches periodically in order to avoid 
> obstructing the air flow excessively.

Yup.  Depending, either a vacuum or a straight-up replacement of the 'filter', I'd suspect.  Or maybe just a good shake 
in some cases.

> OTOH, you also have to have some thought towards what are the benefits of not having the internals of the system 
> coated with dust, vs. slightly reduced air flow.

Indeed.  The internals can definitely handle non-metalic dust, as well as a pretty wide temperature range (caused by 
either reduced airflow or an increase in ambient temperature, or both), so I'd imagine it would be a appropriate 
balance between the two.

> Tom's suggestion of a pressurized cabinet is a good one of course, but that's not possible in all situations.