Removing upper bag of dust extractor

[Lard]

Hi All,
A friend of mine came over to have a look at my modified 2hp setup that uses a combination of a very efficient cyclone (for the larger dust) and extracts the very fine dust to the outside air (very much away from any neighbours etc). My original extractor had the motor housing somewhat detached (best description - sorry) from the bag housing before I adapted it. It works very well.
Anyway, he wants to do the same for his two double bag extractors but they are the type that have the upper and lower bag housing built in alongside the motor (ie different to mine). Both of us are now wondering if he can lose the upper bags and, through adaption, vent the fine stuff outside? I think he can but someone has told him that the extractor will not work without the upper bag?? I can’t see it but am happy to be told otherwise.

Any thoughts are most welcomed.
ta
Dave (edited)

 

[RobinBHM]

I think it will blow most dust outside.

 

[Torx]

Picture of similar?

 

[Lard]

Hi both, ta for replying.
re photos....the first is what mine looked like, the second is the type of both of his.

 

[Lard]

My amended system, including both the large cyclone and the venting to outside works really well and has transformed the workshop....so much so he wants the same.

Actually, looking at both photos now, and apart from having a more complicated adaption, I still can’t see why it wouldn’t work the same. He wants to keep the lower bags (instead of cyclones)....surely the upper bags simply filter the finer dust and so removal would just mean no filter but direct access to outside air?

 

[Orraloon]

It is possible as long as the outlet vent is at least as big as the inlet. Be aware that there could be some mess outside without using a cyclone. May not be nice the day the neighbor is washing his car. My unit is like the one on the left. I put a 1 micron pleated filter on mine. Big improvement over the bag. In fact the bag is next to useless as you could see a dust cloud every time it was fired up.
Regards
John

 

[Lard]

Hi John,
Having slept on it it’s somewhat obvious to me that it will work and i didn't need to post here. I’ve now just got to get my mate to see it too.

I forgot to mention that the querying only started because he wants to locate both extractors fully outside in their own fully ventilated store (outside the workshop that is) and he was told that he’ll have to build them as high as the height of the upper bag. He's sticking to his logic that they’ll be mechanically ‘inoperable’ if he removes the upper bag.

In regard to not using cyclones and the mess (and coming back to what Robin mentioned) I think that as long as he fits some sort of flat breathable cover to the top outlet (in other words a FLAT filter) he can reduce the height to the minimum. Larger, heavier dust falls into lower bag and anything small enough (microns) will vent to atmosphere.

Both of us are very fortunate to not have immediate neighbours and so fine dust is never going to be an issue.

Thanks for all replies.....I’ve used this forum as an extended brainstorm

 

[LJM]

Without a separator (cyclone) before the filter, the larger chips with prematurely wear the filter.

 

[Orraloon]

Hi John,
Having slept on it it’s somewhat obvious to me that it will work and i didn't need to post here. I’ve now just got to get my mate to see it too.

I forgot to mention that the querying only started because he wants to locate both extractors fully outside in their own fully ventilated store (outside the workshop that is) and he was told that he’ll have to build them as high as the height of the upper bag. He's sticking to his logic that they’ll be mechanically ‘inoperable’ if he removes the upper bag.

In regard to not using cyclones and the mess (and coming back to what Robin mentioned) I think that as long as he fits some sort of flat breathable cover to the top outlet (in other words a FLAT filter) he can reduce the height to the minimum. Larger, heavier dust falls into lower bag and anything small enough (microns) will vent to atmosphere.

Both of us are very fortunate to not have immediate neighbours and so fine dust is never going to be an issue.

Thanks for all replies.....I’ve used this forum as an extended brainstorm

I guess an experiment without bags is required to see how much mess it makes. Can always put a bag on again if it proves to be bad. Couple of minutes to shove one stick through the planer should tell if its practical or not.
Regards
John

 

[Peterm1000]

I have this setup (well, almost - I only have one extractor). I have removed the cloth filter and replaced it with a pillow case. My reasoning was that the pillow case is very much more porous than the original thick cloth bag but a flat cover would have been much smaller and would therefore have had far fewer holes (i.e, provided more resistance). I don't think it will work at all without a cover as all the dust / chips would just fly everywhere.

I am not convinced that doing this has improved anything and actually think suction might have reduced - but I have no idea why. Is it because the system needs the resistance at the back end to create a sufficient pressure drop? No idea...

 

[Lard]

Is it because the system needs the resistance at the back end to create a sufficient pressure drop? No idea...

.....thats exactly what I was wondering and, I think, why he thinks it will not work.

Thanks for all your thoughts, I think, as you say, it’s a bit of trial and error. I may even persuade him to make a cyclone (prob end up doing it for him )