Thread: Fielder extractors

good point, I hadn't noticed that. I'm leaning more and more towards the clearvue max one so far, but of course they buggered up the quote and forgot the ducting prices. the Alko one is WAY out of the equation, I wonder why it's so exxy?

Once those bags are conditioned they will perform much better than 5 microns (which is a meaningless stat anyway). However, the main reason for not having any bagged DC inside a workspace is just like all DCs, is that when (not if) the DC or bags leaks this will contaminate the inside of a shed with dust.

The quoted 6000 CFM I would also take wth a pinch of salt. The blurb says it uses 6 x 125 mm inlets A 125 mm duct will at most pull about 800 CFM (down wind with a wet sail) so with 6 x 125 mm ducts the theoretical max flow is 4800 CFM but the way these ducts are arranged to enter the impeller will generate considerable turbulence which means less flow.

In practice once the flow at the impeller is large enough the flow at the machine ultimately depends on the size of pipe you fit to a machine - if you only ever use 1 x 150 mm duct to one machine, then the most sucking power you need is ~1200 CFM. If you have multiple operators that need to use extraction or a large machine like large drum sander is there a need for more.

Originally Posted by riverbuilder

good point, I hadn't noticed that. I'm leaning more and more towards the clearvue max one so far, but of course they buggered up the quote and forgot the ducting prices. the Alko one is WAY out of the equation, I wonder why it's so exxy?

I didn't think that Clearvue supplied any ducting?

Originally Posted by riverbuilder

DC-7000 7.5hp DUST EXTRACTOR 6020cfm - Leda Machinery What about these ones BoBL? I know they aren't a cyclone type, but they are powerful and quiet. The link here says 5 hp but the actual one I'm looking at is 7.5hp and something like 6500cfm. It seems there's a premium price difference for a tapered plastic tube to put a drum underneath. (I realise it's not as simple as that)

Originally Posted by BobL

I didn't think that Clearvue supplied any ducting?

They deal with ezi-duct, thankfully, because ezi-duct don’t seem eager to deal with anyone who isn’t setting up a 1200 square metre workshop with 350 metres of 24inch duct. All my contact with them has gone unanswered so that’s why I asked Stephen at Clearvue to source it. He initially priced for blast gates and transitions and bits but no duct, but he’s sorting it out.

Originally Posted by riverbuilder

You're not wrong there my mate. A HEFTY premium too, to the tune of almost $20,000 for the unit alone plus freight. But, it does come with a built-in fire suppression system.

yes it is ÜBER expensive for an extractor, but if you have seen one in person, you will appreciate the quality.

You can always get an ex display unit from Europe via Machineseeker or second hand machine websites, second hand Nestro, Hocker Polytechnik both are German and sold for around 5k Euro for one without a briquette press, for 10k Euro you maybe able to get a Felder RL style extractor with a German made briquette press attached to the bottom of it - super handy if you make a lot of shavings/dust.

Originally Posted by riverbuilder

They deal with ezi-duct, thankfully, because ezi-duct don’t seem eager to deal with anyone who isn’t setting up a 1200 square metre workshop with 350 metres of 24inch duct. All my contact with them has gone unanswered so that’s why I asked Stephen at Clearvue to source it. He initially priced for blast gates and transitions and bits but no duct, but he’s sorting it out.

My experiences with Ezi-Duct have been quite different. I had bought about 15 metres of flexi a couple of months ago so they remembered me when I ordered a custom made metal reducer for my thicky. It was ready for collection within a few days at a cost of about $50. You might do better visiting their factory.

mick

Originally Posted by Chris Parks

The only self powered cyclone available in Oz is the Clearvue, to my knowledge, no one has imported a self powered cyclone other than a Clearvue but I would be very interested if someone has better knowledge than me. I would be very surprised that anyone who has installed a Clearvue would willingly pull it out for something else. II had better say up front that I was the one who introduced the brand to Oz so I am biased.

What about the Harvey G700 Gyro Air? Its self contained & has cyclonic separation. Also has the Bin system.

However it may not have the capacity the OP was looking for.

Originally Posted by BobL

I played around testing a new RL160 for an acquaintance and found the filter rating was about the same as filter bags or PFs rated at 5 microns. The 5 micron rating is somewhat meaningless as like most cloth or paper filters, once the filters are conditioned the dust layer on the filters that provides even finer filtration.

Bob,

I’m very surprised that you found those RL filters performing at the same level as cloth bags and not even meeting the cheap 1 micron filters you can buy for the generic 2/3hp dust extractors. How confident are you of your testing method? Do you test workshop air after running machines and the extractor or do you just test exhaust air from the extractor?

I just find it hard to believe that an extractor meant for recirculating air environments and meeting euro regs would use a worse filter than a cheap generic dust extractor?

Originally Posted by Austin_Turner

Bob,
I’m very surprised that you found those RL filters performing at the same level as cloth bags and not even meeting the cheap 1 micron filters you can buy for the generic 2/3hp dust extractors.

Note I did not say "cloth bags"
All I can report on is what my dust particle counters show me.
These particle counters were cross checked against calibrated instruments from the Uni where I used to work.

How confident are you of your testing method?

I've been testing dust levels in clean air labs and across a wide range od filter media down to levels some 100's of times cleaner than hospital operating theatres for about 20 years.

Do you test workshop air after running machines and the extractor or do you just test exhaust air from the extractor?

All filters are by measuring dust in air before and after the filters

I just find it hard to believe that an extractor meant for recirculating air environments and meeting euro regs would use a worse filter than a cheap generic dust extractor?

There are basically 3 types of filter bags - Calico, Needlefelt, and pleated filter (plastic, paper or some type of fibre)
Calico bags are the most unreliable as they can easily develop holes and don't have enough thickness for fine dust to be be to bind into/onto the inside to form a self filtering layer.
Needlefelt comes in several thicknesses. The cheapest are usually the thinnest found on budget, low HP DCs, through to the thickest in bigger/larger DCs

99+% of the filtration is provided by the fine dust itself once it impregnates the bag/filter material. Thinner bags rely more on the dust itself to act as filter than the thicker bags
I was surprised to see that the unconditioned RL filters performed no better that a thin needle felt DC filter but after a few days when the filters became condition the RL filters were fine - as were most needle felt and pleated filters.

The issue with Most DCs are not the filters but leaks - and they all sooner or later do this. That's why locating or venting a DC outside is so important.

The current Euro standard for wood dust in air is nothing to write home about especially as it does not take into account particle sizes, or age of workers, or any pre-existing health conditions. Last year the EU had major conference to review wood dust standards and my understanding is they are still working on developing lower exposure values. In the meantime (especially for seniors or anyone with a pre-existing health conditions) it is probably safer to operate closer to the much lower levels recommended by WHO for PM2.5 levels for the general population. BTW those levels are also almost certainly set to be lowered.

Thankyou BoBL, when you say leaks, I’m presuming they would be after the cyclone and filtration membranes? How would one check for leaks? with smoke in the duct? Watching for it to escape?

Originally Posted by riverbuilder

Thankyou BoBL, when you say leaks, I’m presuming they would be after the cyclone and filtration membranes? How would one check for leaks? with smoke in the duct? Watching for it to escape?

Like any DC there's only need for testing a cyclone if it's used inside a shed thus requiring a filter be used. For a good separation cyclone like a Clearvue the filters can remain in place without needing cleaning for multiple emptyings of the main sawdust bin. For less able cyclones the filters would need to be cleaned more often which is when leaks are more likely

For regular DCs leak testing needs to be done using a dust particle counter and is a right PITA.
It takes skill and lots of time to do properly and it's one of the last things wood workers want to doing when they'd rather be woodworking.

It's not possible to wave a budget end dust particle detector in the general vicinity of a plastic collection bag or filter in the hope of finding a small leak. Remember a small leak acting over a couple of hours can still pump out a lot of fine dust.

To start with the background level of the shed dust meets to be measured and to do this accurately requires many minutes especially if its changing all the time.
Leaks are typically pin pricks in the bags or filters or around the rim of the filter/bag housing so the particle detector has to be held close to a possible leak and may require a minute or two to collect enough data to make a meaningful measurement.

Thanks Bob,

I was confused by the reference to performing at a similar level to 5 micron filter bags, and then the reference to the 5 micron measure being meaningless for cloth or paper filters in the next sentence. I conflated the term filter bag and cloth filter.

Thanks, your professional expertise is certainly extensive, it sounds like your testing method is based on both training and experience!

You were surprised at its unconditioned filtering level, but said that it performed well after conditioning for a few days, similar to other filters. Does this mean it was capturing a sufficient percentage of the finer (<5 micron) particles and generally providing sufficiently clean air to recirculate if needed? I understand it is always preferable to vent outside, but if you have to vent inside as the OP wanted to do...would you be comfortable to do so yourself?

Yes we were talking about the regulations just the other day, I understand there are significant shortcomings in regulation. I was making the point because my impression was that the RL extractors made much greater claims about filter performance and air quality than many other extractors around and so I would have hoped their choice of filter medium would have been carefully made to ensure excellent filtration and airflow performance.

Originally Posted by Austin_Turner

You were surprised at its unconditioned filtering level, but said that it performed well after conditioning for a few days, similar to other filters. Does this mean it was capturing a sufficient percentage of the finer (<5 micron) particles and generally providing sufficiently clean air to recirculate if needed?

Yes.

I understand it is always preferable to vent outside, but if you have to vent inside as the OP wanted to do...would you be comfortable to do so yourself?

If I had to pick any medium size extractor that absolutely had to vent inside I would pick a ClearVue with the super fine filter on its outlet. Cyclones have fewer leaks, don't suffer any loss of performance as the filters clog up, and the Clearvue in particular has such good separation it means the superfine filter need very little cleaning.

If I had to pick a non-cyclone extractor to vent inside and had the $$ then the Felder would be a good choice (mainly because of the bins), but no matter what bagged filtered DC I was using I would consider running a particle counter along side it and periodically (at least after every bin empty) inspecting it for leaks.
I was out at a mens shed earlier today and they are looking at an RL300 or 250 and saw the quotes
It's a big shed (200m^2) but its still not a production/commercial environment (lots box toy making etc) but some of the members don't want to vent outside.
A couple of the ex-engineer members were very keen on the Felder but I could see the members trying to raise the money had real concerns.

Thanks, good to know.

How does a mens shed make money? That would be what $20k+? Selling toys at markets?

Though the big RL300 inside with manual bin doesn’t make much sense to me, if you need 300mm extraction, you probably produce so much waste you want it briquetteing or pushing outside with a loader hopper or silo? I found an old thread with someone here emptying 12 bags a day at the dump from an RL...all I can think of is the lost productivity and dust exposure from bag changing all day.