do you understand this?

[johnakay]

I bought one of these in line dust extractors last november and I must say that I'm disapointed.it will only draw weld smoke (fumes) from about 12" any more the smoke just driffs away.
I'm not to clever as far as reading these info......(what does it mean.) I just want it to draw the smoke from about24" to 30". am I asking to much?

http://cgi.ebay.co.uk/In-Line-Duct-...arden_Hearing_Cooling_Air?hash=item2a04813941

 

[MarkMG]

The problem is that it is not designed for dust, it is designed for ventilating greenhouses or plant (organic green type) rooms.

 

[Luke]

Without even getting in to the nitty-gritty of the data, the thing's only 100w, it's never going to do much.

The graph's only saying "the harder you make it push the less it'll shift in total"

 

[chunkolini]

'green houses'would that be for growing 'pot' plants?

I have made misbuys like this on fleabay, it is a right pain. I usually out them back up for sale reword them and turn about 50p profit.

Chunko'.

 

[peterd51]

Hi,

could you extend the input side with 4" tube or pipe to get it closer to where your work is?

Maybe have a funnel around 1 foot square in the end? I seem to recall many years ago when I did the welding course they had something like this on each bench, especially for the arc welding.

Regards
Peter

 

[brightspark]

Without even getting in to the nitty-gritty of the data, the thing's only 100w, it's never going to do much.

The graph's only saying "the harder you make it push the less it'll shift in total"

as luke says the pressure to push is pa .and the 200 m3 is how many cubic meters of air per hour the fan can pull out of a room. so unless u put a hood over your job quite close and the fumes dont rise due to draught ect it will be useless

 

[Debs.]

I bought a cheap (£9.99) garden blower/vac., on special offer from B & Q, a while ago.......it`s 1800 watt. and hangs up on light chains from the workshop roof with the broad vacuum-duct above the welding/grinding table and the exhaust ducted out under the eaves through a couple of metres of 4" flexi. mylar-type ducting (connected to where the leaf collecting bag would attach)......quick flick of the switch next to the bench and away it goes.....cheap and cheerful, but it works well.

 

[brightspark]

QUOTE=Debs.;192529]I bought a cheap (£9.99) garden blower/vac., on special offer from B & Q, a while ago.......it`s 1800 watt. and hangs up on light chains from the workshop roof with the broad vacuum-duct above the welding/grinding table and the exhaust ducted out under the eaves through a couple of metres of 4" flexi. mylar-type ducting (connected to where the leaf collecting bag would attach)......quick flick of the switch next to the bench and away it goes.....cheap and cheerful, but it works well.[/QUOTE]

 

[Robotstar5]

I bought a cheap (£9.99) garden blower/vac., on special offer from B & Q, a while ago.......it`s 1800 watt. and hangs up on light chains from the workshop roof with the broad vacuum-duct above the welding/grinding table and the exhaust ducted out under the eaves through a couple of metres of 4" flexi. mylar-type ducting (connected to where the leaf collecting bag would attach)......quick flick of the switch next to the bench and away it goes.....cheap and cheerful, but it works well.

and as a bonus, you never have problem with fallen leaves (leafs?) on your workbench!

 

[johnakay]

The problem is that it is not designed for dust, it is designed for ventilating greenhouses or plant (organic green type) rooms.

its not for dust clearing that I bought it for..welding fumes.
I bought one of these hoods, I don't want it to low and catching my welding helmet...
I want some that's a permanent fixure and smallish.
anyway thanks for your replies. john

 

[rtcosic]

looking at the performance curve that ventilation fan will only move about 100m3/h when a little bit of ducting is added. It's not much better than the ventilation fan I have fitted to the downstairs cloakroom.
Debs garden vacuum is probably shifting 750-1000 m3/h according to some specs I've just looked up. Plus it has a shaped inlet nozzle specifically designed to 'direct' stuff into it. Noisy though!

BUT, the specs are inconsistent in the eBay link. The spec sheet says it draws 106W at full power, but the blurb says “Only 28 watts power consumption at full speed!!”.

I would guess you would need a superficial velocity well over 0.5 metres per second at the inlet to your ‘hood’ if you want it to be as far away as you say. If the ‘hood’ is say 500mm x 500mm that’s 0.25m2, so you need to move at least 0.125m3/second or 450m3/h.
So Debs 750-1000m3/h seems a pretty good guess on her part.


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