Thread: Clearview Cyclone

Originally Posted by warmtone

Hi David
Thanks for the kind offer. ....... A pity you're so far away!

But there's a chance I might end up doing a trip to the Murray over the holidays so it's

a possibility.

Meanwhile I plan to give Chris a call and have a chat re shipping costs and ducting logistics

Brian

if you do scout out the cost of 2 units and shipping b/c i'm considering one as well

Originally Posted by MatMann

if you do scout out the cost of 2 units and shipping b/c i'm considering one as well

No problems.........

One of the decision points will be whether to vent the clear view outside which I would prefer to do.This will avoid any recirculation of fine dust and also avoid the need for expensive filters which should bring the price down.

The problem for me is logistics I would need a longish 5m exhaust duct. I assume this isn't a problem?

Do you require the filter and which model do you need?

Originally Posted by doug3030

.. But what impact do these filters have on the actual CFM through the ducting? Would we get more suck for our buck if the needlefelt or pleated cartridge was removed from the system completely?

Provided filters are kept clean, the limiting step in most DC setups will not be the filters but the ducting and machine port sizes.

My first dust extraction device many years ago was a sherwood 1hp machine with a cloth bag and it sat on the floor with the bag lying horizontal so it would fit under a bench or wherever. I think it was ambitiously rated at 950 cfm.

The 950 CFM will be the unrestricted fan rating. Used with 4" inlet will immediately drop the CFM to almost any DC to ~400 CFM. The small bag on the small dc you describe is very restrictive and it will clog quickly but the efficiency of the filters I measured on one of these small DCs turned out to be surprisingly high.

To improve its performance, I constructed a cyclone out of two 44 gallon drums to collect the visible dust and chips. I stripped everything but the impeller off the dusty and mounted the impeller on top of the cyclone and vented the exhaust side of the impeller out through the side of the shed. No filter to cut back on CFM, anything not collected in the cyclone is vented outside the shed, even though the cyclone and impeller are within the shed where I can see them.

The risk with this setup is that there are still pressurised components of the system inside the shed so small leaks could go unnoticed. It is better to put every bit of the DC outside the shed if you can.
Chip collectors such as you describe may produce more of a restriction to flow than they're worth.

Now the reason I ask about how much the bags/pleated filters restrict airflow is because I upgraded to a 2hp dusty
.
.
it does not really appear to be providing significantly more suction than the 1 hp without a bag was achieving. I put this down to the restriction of the air flow as a result of the needlefelt bag, but I have no conclusive proof yet that this is the case.

This is because you are probably using 4" ducting and machine ports. Remember a 4" duct simply cannot transmit more than about 400 CFM using either a 1, 2 or 3 HP DC. A 1 HP DC will pull about 360 CFM, a 2 HP about 385 CFM and a 3 HP about 410 CFM even through a very short length of ducting At these flow rates it is impossible to tell the differences in flow by eye or hand, and can only be measured accurately with a flow or pressure meter.

Once I do the planned modifications if there is a significant increase in airflow that might be it. But part of the project is also to "bore out" the cyclone to 6" inlet and outlet and make a 6" intake port for the impeller unit and ensure no choking on the impeller outlet as it goes through the wall, so I may not be able to tell if teh bags are the restrictive element they appear to be.

This will be a waste of time unless you upgrade to 6" ducting and ports.

PS: when I say "venting out through the wall", it is actually through a piece of 12mm ply cut to the size of the shed window with a hole cut for the dusty exhaust and has two high-capacity exhaust fans mounted in it that deal with a lot of the invisible dust and move the hot air out of the shed in summer.

The exhaust fans are a good idea provided there is a large opening preferably in the wall opposite the shed.

Any filter will restrict flow when it is dirty. Last weekend I tried to measure the filter efficiency of a DC with a needle felt bag. The first thing I noticed was the flow rate out of the filter was much lower than usual (so low that I could not measure the efficiency). I then checked the suck at the DC inlet and found that to be near zero but there was no restriction at the impeller. It turned out that the filter had about a 1cm layer of super fine dust caked up hard against the NF bag and it was pretty clear the filter had not been cleaned for some time. The DC was also connected to a home made chip collector (CC) and assumed that the CC would catch most of the dust and that would protect the filter so he would not have to clean the filters as often. This is a common misconception about chip collectors. A chip collector collects the big chips but lets the finer stuff through so they form uniform layers of fine dust on the filters which will block the filter quicker than usual. The fine dust layer just needs a little damp air on it and it will glue itself to the filter or dust layers underneath

Home made chip collectors make it easier to dispose of the chips but the filters of their DC may need cleaning more often than usual. Properly designed cyclones will remove a large proportion of the fine dust as well so they don't have this problem and will significantly reduce the time needed between cleaning of filters.

Gents, BobL is dead right about duct and port size.

I recently installed a Clear Vue system and ran a 150 mm line through the shop. The air flow is magnificent, but only where I have well designed 150 mm ports.

My jointer/thicknesser still operates with its standard 100 mm ports, and while the suction is better than when I was using a 1 HP dusty, is is woeful compared to the ports that have been properly upgraded to 150 mm.

Just up-sizing a port to 150 mm might not be enough. That worked on my drum sander, but I needed to make a few minor mods to some other ports/machines to get the air flowing in the right places to do a really good job of dust extraction.

Originally Posted by BobL

Last weekend I tried to measure the filter efficiency of a DC with a needle felt bag. The first thing I noticed was the flow rate out of the filter was much lower than usual (so low that I could not measure the efficiency). I then checked the suck at the DC inlet and found that to be near zero but there was no restriction at the impeller. It turned out that the filter had about a 1cm layer of super fine dust caked up hard against the NF bag and it was pretty clear the filter had not been cleaned for some time. The DC was also connected to a home made chip collector (CC) and assumed that the CC would catch most of the dust and that would protect the filter so he would not have to clean the filters as often. This is a common misconception about chip collectors. A chip collector collects the big chips but lets the finer stuff through so they form uniform layers of fine dust on the filters which will block the filter quicker than usual. The fine dust layer just needs a little damp air on it and it will glue itself to the filter or dust layers underneath.

I just came in from going back to this air filter. During the week the owner had shaken out the filter and replaced it. The flow was slightly better than last week but still well down on what I normally observe for a 2HP DC and the filter was fair pumping out the fine dust - ie approx 9 times above background.

This time I had also brought with me my flow measuring gear and the flow at the 4" DC inlet (ie zero ducting) was ~150 CFM!

The distended shape of the filter bag told me the filter was still clogged. I could clearly see that the owner had attempted to clean the filter bag, but the plastic bag underneath had not been emptied was still about 2/3rds full of purified ultra fine dust.

I suspected that even though the filter bag had been shaken out, as soon as the DC was turned on, the swirling action had immediately swirled that very fine dust still in the plastic bag all over the inside the DC. On opening up the DC - sure enough there was a nice fat layer of fine dust covering the inside of the filter. The dust inside the plastic bag (and lining the filter) is bulk superfine stuff that has gone through the chip collector is appears to be easily fluffled up to fill the inside of the DC. This is a good lesson for people using chip collectors to make sure their DC's are kept well maintained.

Originally Posted by BobL

I suspected that even though the filter bag had been shaken out, as soon as the DC was turned on, the swirling action had immediately swirled that very fine dust still in the plastic bag all over the inside the DC. On opening up the DC - sure enough there was a nice fat layer of fine dust covering the inside of the filter. The dust inside the plastic bag (and lining the filter) is bulk superfine stuff that has gone through the chip collector is appears to be easily fluffled up to fill the inside of the DC. This is a good lesson for people using chip collectors to make sure their DC's are kept well maintained.

When I bought my 2hp dusty it was second-hand from a forum member. It was full of chips and the needlefelt bag was so loaded with fine dust you could hardly push the bag in when the dusty was turned on. I cleaned it out and connected it on after my home-made cyclone, Several months later after quite a few hours of use, the plastic bag is still effectively empty and the needlefelt filter is still clean. I bang on the sides of the needlefelt bag occasionally to see if anything falls down into the plastic bag but so far nothing. I guess it was worth the extra effort to make a cyclone instead of just a chip collector.

Doug

Originally Posted by doug3030

. . . . . I guess it was worth the extra effort to make a cyclone instead of just a chip collect

Sounds very good, provided you still have sufficient flow.

I had a trip to Carbatec Melbourne to buy a few odds and sods including some wood turning tools.

I took the opportunity to have a look at the new Jet Vortex cyclone that's rated at the usual 1200 cfm .. With 2 4 inch ducts.

Big claims are being made about this new dc regarding vast improvements to dust and chip collection and improved efficiency from lack of filter clogging.. Not much of a true cyclone to be found just a short section of internal circular chamber but maybe theres a smart design that's not obvious.
Noise levels were very acceptable usual vg Jet build quality and reasonable suction at the inlet of 4 inches. But 1200 cfm? Based on Bobs advice unlikely!

Decided to have a look at the Carbatec more seious alternatives first one at about 2k well built proper cyclone and 2micron pleated filter with solid bin ...and mobile. Suction was rated at 1600cfm and noticeably better than the Jet even with 4 inch ports. It seemed like reasonable value and it was fairly quiet. ModelUB 2100ECK The white one in the catalogue.

But I was more interested in the larger unit fitted with a six inch port interestingly rated at 1354cfm CT 702 the blue unit at 2.5k

Air flow on this machine was very impressive. The 6inch ducts clearly make a huge difference. Well made support frame noise level still acceptable. I assume the above options have been considered so Can someone tell me why the Clearview is superior?

I suspect the bigger motor and impeller make a significant difference but is it the design of the cyclone and quality of filter as well?

Originally Posted by warmtone

I had a trip to Carbatec Melbourne to buy a few odds and sods including some wood turning tools.
I took the opportunity to have a look at the new Jet Vortex cyclone that's rated at the usual 1200 cfm .. With 2 4 inch ducts.

That is usually the max flow of the fan without bags and without any ducting (or see below).

Decided to have a look at the Carbatec
Suction was rated at 1600cfm . . .ModelUB 2100ECK The white one in the catalogue.
. . . rated at 1354cfm CT 702 the blue unit at 2.5k

These figures are a bit more realistic but I still doubt they are accurate because they have a cyclone attached to them which has to reduce flow.
A 2HP unit without a cyclone will struggle to get more than 1000 CFM thru 6" ducting (the 6" ducting is the limiting factor until the filters get dirty) while a 3 HP will struggle to get more than 1250 CFM thru 6" ducting.
Remember even the best made cyclones will reduce flow on any DC unit.

What I am starting to suspect is manufacturers just stick an air flow meter at the intake and take a reading in the middle of the duct and calc the air flow from the linear air speed X the cross sectional area of the pipe. It's a lot more trouble to do it accurately and take into account the fact that the air speed at the surface of the ducting is near zero . If I use a one shot measurement (ie just measure the air speed in the middle of the pipe) I get 1767 CFM but when I do measure it systematically across the diameter and integrate the air speeds etc I get 1268 CFM - that's a big difference.

The reason the Clearvue is so good is that their cyclone/motor/impeller combination offers minimal interference to overall flow.
A poorly designed cyclone will eat up as much as 1/3 of the pressure available from a DC to drive air.
Clearvues typically use a bigger motor (5HP) / impeller AND the cyclone is designed so that overall it loses around 1/9 of the pressure available.
They also use a VSD which enables the motor to spin at 60 instead of 50 Hz.

If you are able to
- vent outside,
- use a large area filter (ie takes up space),
- and are prepared to clean the filters regularly,
Then removing ANY cyclone will boost overall pressure and generate a slightly higher airflow.

Originally Posted by BobL

The reason the Clearvue is so good is that their cyclone/motor/impeller combination offers minimal interference to overall flow.
A poorly designed cyclone will eat up as much as 1/3 of the pressure available from a DC to drive air.
Clearvues typically use a bigger motor (5HP) / impeller AND the cyclone is designed so that overall it loses around 1/9 of the pressure available.
They also use a VSD which enables the motor to spin at 60 instead of 50 Hz.

If you are able to
- vent outside,
- use a large area filter (ie takes up space),
- and are prepared to clean the filters regularly,
Then removing ANY cyclone will boost overall pressure and generate a slightly higher airflow.

Hi Bob, many thanks for you informative response and as I expected Cleavue simply does it better!
Is the VSD included in the price? These are great devices but a high power VSD is usually expensive

Originally Posted by warmtone

Hi Bob, many thanks for you informative response and as I expected Cleavue simply does it better!
Is the VSD included in the price? These are great devices but a high power VSD is usually expensive

Chris does sell VSD units for the Clearvue Cyclones but whether that is standard or optional, I think you'd be best to ask Chris that.

Originally Posted by warmtone

. . . These are great devices but a high power VSD is usually expensive

Not really - a 4kW VSD can be obtained for as little as $150.

From memory, the Variable Frequency Drive supplied with the Clear Vue is about $300.00 (in addition to the cyclone/motor etc). By comparison, I was quoted $2,000+ to run a 3 phase line to my workshop.

speaking to Chris today, they offer a single phase motor by using a variable frequency drive ( i.e. effectively a soft start motor)

I've got to ring him on Monday for some more info, so I'll answer your PM then Warmtone