air watt?

[johnakay]

I've got a polishing machine which I use for polishing my rails etc.
I want to make a dust extraction but not sure what air watt I should be looking for.
some of these so called high powered or high wattage cleaners have poor suction.
so what would be a starting point for anything decent.
one vac has (538aw Air Watts)
sealey got this (Airflow: 78m³/hr)
dont know what that means so any info will be much appreciated.

 

[angellonewolf]

i belive the air flow is 78m3 per hour so if you have a room 27m in volume it will hange the air in the room 3 times in the hour

there are calcs on line for differant types of things certain jobs requre so many changes per hour so its there so you can work out what is required

 

[johnakay]

its the fine dust that I want suck up.
often once the mouth is open on the end of the tube theres doesn't appear much suction.
so I get dust floating around. bigger stuff get sucked in but not fine dust.
this what I trying to eliminate.

 

[Parm]

With extraction and powered machinery you need to bee looking at ejection velocity from your poli#her and the location of the extraction.

position the capture in line of fire you will have natural entrainment and not much air needed.

position it wrong and you’ll need to move an enormous amount of air for the same level of capture

 

[MCKDAVID]

have a look at LEV, local exhaust ventilation guidelines, it'll give you some ideas, agreed it can get complicated very quickly with COSHH etc, but the fundamentals are fairly straight forward, Simply put, the point is "local", basically the closer to the point of extraction the more efficient the capture rate is, the efficiency drops off radically the further away it gets.
Fine dust is always more difficult, as is any particulate extraction, the other thing to think about is what you do with it at the other end,? where is it being discharged, out the back of a hoover, and chances are you're just moving the dust from one area to another. A lot of these hoover filters are little more than a woven pad, or a piece of foam, few would ever be classed as HEPA.

 

[johnakay]

I was thinking of making a wrap round guard and have the vacuum at the point of fling which is at the top.
I know I wont get it all but most of it which is what I'm after.
I dont have any space etc for an industrial filter.
I only polish now and again.