HVLP Extractor advice please

[ScouseKev]

Re. HVLP extractors used with Cyclone / Thien.

Ive noticed on a few forum photos that some members have removed the top filter bag and blocked it off with MDf .
Whats the reason behind it? I know cyclones remove 99.9% of the dust but is it ok to do this?

Others turn the extractor 90Deg and have the motor directly above the cyclone, with the bottom bag coming out horizontally.

I'm planning a Thien separator and i want to get as much info as possible before building.

thanks

 

[theartfulbodger]

Possibly the bottom bad that's removed? If there was no porous bag attached there would no air flow...

Sorry I can't help with your question. Other, less tired people will be along soon

 

[Chems]

The top bag is the filter bag and the bottom the collection bag. So the Cyclone/Thein is doing your filtering so people take the top bag off. I have had customers tell me they have removed both bags from their extractors and just vent the air straight out of the extractor after going through the Cyclone. Though I would recommend a fine 1 micron filter as a final barrier to catch the dust that is to fine to be separated out.

 

[ScouseKev]

Thanks chems.

Just check i'm reading this correctly.

So the bottom bag then doubles up as the filter and collection bag for anything sub 1 micron that doesn't get separated out by the cyclone?

 

[theartfulbodger]

The top bag is the filter bag and the bottom the collection bag.

With you so far

But

So the Cyclone/Thein is doing your filtering so people take the top bag off.

So where does the air flow actually go if the top bag is removed and blanked off?

 

[Chems]

The airflow will still escape via the bottom bag, both bags are the same, gravity causes the waste to fall into the bottom bag. Its no different than how this extractor works:

Normally you would have to worry that as the bag fills up the amount of air able to escape easily would be reduced thus making the extra less efficient. Something we've all experienced when the bags started to get really full. But with a Cyclone/Thein the bag should never get anything in it.

 

[theartfulbodger]

Thanks, Chems! I have one cloth bag on the top of mine and a plastic bag on the bottom if that explains my confusion.
The top bag to filter and the bottom bag to collect.

Do some extractors have two cloth bags?

 

[ScouseKev]

Thanks for that Chems, big help.

I notice you have the same extractor as me, the Sip 3hp. Do you have it ducted around the shop? If so , whats the longest run from extractor to machine? And is there much of a drop in suction?

 

[Chems]

@Bodger, removing the top bag won't work if the bottom bag is a plastic bag as then there will be no exhaust as those bags are air proof. Most if not all extractors are sold with both a cloth top and bottom bag.


@Kev, I don't have it ducted around the shop but do use it with a long flexible hose that can stretch all over and I've never noticed any drop in suction. The maximum distance I've used it is probably 20 feet.