dust extraction query

[johnnyb]

i am currently setting up a workshop and am thinking of using an enormous wet and dry vac that i have as a dust extractor. it has three motor totalling 2900watts. it has a 50mm internal bore pipe that swells to about 96mm where it enters the barrel. the filter is thick felt and needs shaking occasionally in use. it is a gerni wv600. it has incredible suction but is really loud. do you think this would be suitable to extract from all the major machines? i am thinking of using plumbed in soil pipe with 100mm flexi to the machines. i was hoping to dream up some good idea to overcome the odd size inlet to the machine. could i cut the bottom of the bin and fit sacks or would they just suck to the motor? although it has a large capaicity much is consumed by the motor. another idea may be to add another chippings bin ala axminster. any thoughts would be greatly appreciated.

 

[JFC]

You need a cyclone :roll: ..................wait for it ....

 

[Barry Burgess]

Jason who says???. He could get away with a dust bucket that would allow the conversion of his 50MM to the 110mm soil pipe? johnnyb you have to convert the 110mm back to 100mm to fit most blast gates. Something like this

Barry

 

[Adam]

Surely it won't work. Vacuums operate by sucking a relatively small volume of air through at high pressure - ideal for power tools and carpets. Large machines such as tables saws, bandsaws and particularly planer thicknessers need large volumes of air at relatively low pressure - which needs chip collector (i.e. large dust extractor) which is 100mm all the way through. If you connect a 50mm internal pipe to 100mm its going to suffer a terribly - they just aren't designed to work that way. Their will be a huge drop in pressure where it transitions.

It'd be fine for all power tools etc though.

Just my thoughts - I'm sure someone else will be along soon!

Adam

 

[Barry Burgess]

Adam that's why I suggested a dust bucket to try to reduce the effect of the 50mm to 110mm. You also have to remember that he is using a 2900W triple vacuum that might be able to cope. It is not ideal but might work. I tried it with a 2000W single vacuum and it was just about acceptable.
Barry

 

[Adam]

Ahh I see. If you plumb everything in in 100mm pipe its not lost effort, even if the vacuum doesn't prove ideal. You could just connect something else to it (cyclone/D/Ex etc). I reckon getting all the pipework in place is the hardest bit.

Adam

 

[johnnyb]

the actual inlet in the bin is strangely 97mm(held by a quick clip) this then reduces down to 50 (internal). if i could keep the pipework all (nearly) at 100mm/110mm would this improve its efficiency? this is a large machine and with other tools wiil sometimes trip a 32 amp ring. the run will be about 10 m. the bin is fitted with a deflector to stop the dust going straight onto the filter. i will try it non plumbed in first. my main concern is it doesnt hold a massive amount as the motors take up internal space and it is not really easy to empty. it has an airflow of 572m3/hr or 159l/sec much higher than the wv 2000 axminsters biggest at 390m3/hr.

 

[RogerS]

I would go with barry's suggestion of a collector.

I use a chunky 2000W round vacuum device and although it sucks well and the volume does cope with chippings from a moulder and thicknesser, the volume is too small to be practical. Inside there is also a deflector and this can be rotated..so I rotated mine to fire around the circumference and this sort of sets up a very weak cyclone and that also helps.

The other main drawback is dust as the filter does get clogged up quickly. But that has been fixed with a minicyclone in circuit.

Having said all that, it is pain to keep swapping it around from machine to machine and that's not helped by the fact that the definition of 100mm and 58mm OD seems a bit of a moveable feast. So I end up wrapping tape around each joint, then undoing it again, then redoing..... :evil: I also noticed that extending the 58mm hose by double it's length seems to reduce the power at the suck end (....still fine inside the cyclone which continues to work well.) and so I do see myself getting an extractor arrangement soon and plumbed in as far as I can.