Cyclone.. Which one? ClearVue won

[Chris Padilla]

http://www.sawmillcreek.org/showthread.php?t=9933

A little thread I contributed to quite a bit...the Bill Pentz design I cobbled together. Man, this things moves some serious air...just need to get the ductwork to it now.

[Bob Dodge]

Jim,

I agree with what you're saying, to a point, but remember, we're talking about a "system performance" curve here. In otherwords, it's "the system configuration" which I'd be buying, not "that system" but with the inlet removed, and an 11" pipe added, or an 11" pipe acting as a hood on a 7" inlet. I'd wanna know what it pulls "as I buy it".

I'm sure there are lotsa people out there, who would calculate their pipe based on that 1400 cfm figure. If they did, they'd be in for a rude awakening. The "entry loss" alone on a 6" network, or a 7"main/6"drop, would kill that 1400 cfm rating. He'd be lucky to be pulling 1000 cfm after the reduction is taken into account, BEFORE he/she starts adding ducting.

Remember, the post that started this thread, had ED contemplating the purchase of a 5hp dc. I imagine that this percieved "need", is due to all the hype surrounding CFM. There's not a single machine in Ed's arsenal, that requires more than a 6" pipe, or 800 cfm at the business end of that pipe. What Ed needs, is the suction to provide that 800 cfm, where he needs it.

He simply has to calculate the resistance of his "worst-case scenario" branch, then compare that to the "system performance curve" of the dc he's looking at. He can't just look at 1400 cfm and calculate from that flow, he has to take into account, the dc's new entry-loss, and start from THAT point on the curve. The entry-loss difference from an 11" pipe, to a 6" pipe, would be staggering.

A 5hp dc might not necessarily fare much better. You HAVE to consider the operating pressure. Putting a 6" pipe, on a 5hp dc, is a lot like using an undersized 4" main, on a 2hp dc. That 5hp dc, may only "shine", if used with a low resistance 9" pipe for example. Suction is key. He may find for example, that he could operate two machines simultaneously, on twin 6" drops, off a 9" main. That would be a nice high-volume/ low-suction scenario. But if he were to use a 6" main, and operate only one of those machines at a time, he may find that he'd air-starve a low-suction 5hp dc.

Ed's shop is nice and roomy (28x42), but as he said, most machinery is in the front half of the shop. Any "real" 2hp dc should handle that, as long as the network is efficiently layed out. That's a pretty general statement however. To know more precisely if his needs will be met, you need the real numbers, and THAT, is what a system curve is supposed to show.

If Ed found 2" of resistance in his pipe, and simply looked at the stated 1" operating point on the system curve, then added his 2" of resistance to that point, he'd be reading his cfm expectation at the 3" point. He'd be wayyyy off. Why? Because he'd have no idea what the original test configuration was, that generated the 1400 cfm at 1" sp reading. He'd naturally expect that this is the point at which his system tested, "as sold". That's the whole point of a "system curve".

In fact, he couldn't even begin to calculate his pipe resistance, UNTIL he knew how many cfm the dc is pulling "as sold".

Bob

[Jim Becker]

Bob, Oneida's tests are all done with pipe that is the same size as the inlet. I've been in their test lab in Syracuse physically and seen the setup. It's essentially done the exact same way that things were pictured in the WOOD Magazine cyclone article in December 2003. They test competitive systems exactly the same way...there were at least five of them lined up when I was visiting in February 2004.

I really don't know where you're getting this 11" pipe thing...there is no system anywhere in the range we talk about in these forums that has an inlet bigger than 8" that I know of. The norm is 6" or 7" typically with a commercial 5hp system having a 8" inlet in Oneida's case. Only when you get to their big 5-7hp direct drive system to you get a 10" inlet...and that's for a realy big shop. (I'm using Oneida as the example purely because that's the vendor I'm most familiar with)

As to your other calculations, I'll leave that to others more knowledgable on the subject to comment on.

[Bob Dodge]

Quote:

Dear Allan,

Thank you for your e-mail regarding performance on our S 2-6 CYN dust collector.

The air flow for the fan is 1200 CFM at 1" S.P. The pressure drop over the filters is approximately 2". If the ducting has a static pressure drop of 6", the air flow will be 700 CFM.

The inlet to the fan is 7". You cannot hook up a bunch of 7" ducts to the system. A 7" duct would allow for (3) 4" duct connections or (2) 5" duct connections to allow for the proper drawing capacity.

I hope this information is helpful.
-------------------------------------------------------------------------

You've illustrated my point precisely. The 1" is external static. So is the further added 6" of "external static" producing 700 cfm.

1200 cfm,at 1" sp, is not the "operating point" of the dc. It's the cfm flowing, with 1" sp added to the inlet. The clue, was in the 2" pressure drop at the filter.

The operating point should be about 3.733" sp, to pull 1200 cfm through a 7" inlet. That would yield 2.474" friction loss, and a velocity pressure of 1.259"sp.

If you've interpreted Kraemer's response in a way that suggests 1200 cfm is a "free-air" fan only rating, all you have to do is look at the 1200 cfm fgree-air rated consumer dc's. They barely pull 800 cfm at the inlet, let alone, adding another 6" of pipe resistance.

Bob

[Bob Dodge]

Jim,

I know all of that. That's not what I'm saying here.

What I'm saying is, they show a cfm rating of 1400cfm "AT" 1" sp. Explain to me how you think they can flow 1400 cfm through a 7' pipe, AT 1"sp.

To get that 1" reading, you'd have to measure it in an 11" pipe. There's no way around it.

Bob

PS. Why I mentioned it, was in regard to the recent CFM war. A few months back, they showed a lower cfm rating, but at 2" sp. Then when the cfm war escalated, I saw this new 1" sp rating, and higher cfm. There was no mention of a component change, to UP the dc's performance, in fact, the lower sp point illustrates pricisely that. It was just a different test procedure. Pressure was lowered, not raised.

Had the dc's performance been increased, then so would have risen the dc's original operating point.

[Allan Johanson]

Bob,

I don't care about other DCs and "free air" ratings. That's irrelevant. You also didn't see the context of my question to Kraemer which included examples from their curve and what would I see if I measured the airflow with a length of ductwork, etc. I don't have a copy of that to show you.

All ya gotta do is look at this:

******

The pressure drop over the filters is approximately 2". If the ducting has a static pressure drop of 6", the air flow will be 700 CFM.

******

Especially the ducting part. If I had 6" SP loss in ducting and used that value alone with their chart (the one called "direct drive blower performance chart")...

http://www.kraemertool.com/datas26cyncdn.htm

...I'd see about 850cfm. But that isn't the case. It can't flow that much air with 6" of ducting. You need to add on the overhead for the filters that they said (2").

Now look at that chart again, but at the 8" SP mark. Now you've got the 700cfm the Kraemer guy said it would flow with 6" SP loss of ductwork in place.

This e-mail along with my original questions and examples to them about what I would see in my shop if I measured the airflow and SP values makes this very clear. Sorry you can't see it.

If you still think it's something else, maybe you should talk to them.

I think you're overthinking this too much. Time to stand back and relax a bit.

Cheers,

Allan

[Bob Dodge]

Allan,

If you've invented a way of pulling 1200 cfm through a 7" pipe at 1" sp, I'm sure some physics professors would be quite anxious to hear about it.

Bob

PS. Go to the Beacon Engineering calculator, and TRY it. Put ANY inlet you want on it. Use the SMALLEST pipe length possible. 1 foot. and,,,,good luck.

http://www.freecalc.com/ductfram.htm

At the top, where it says "duct type", enter "round". Enter 7" pipe, 1200 cfm, and delete the 100 foot duct length, and enter 1 ft duct length at the bottom of that chart.

Scroll down to "entry configuration", and choose "plain end duct".

Scroll to the bottom of the page, and for duct discharge, choose "Vertical discharge, no loss". Hit "calculate" below that. YOU tell me what you see.

I see 2.274" total duct loss, AND 1.259" Velocity pressure.

Total static pressure, is the combined total of those numbers. 2.274 +1.259 = 3.533" Total SP. That's the MINIMUM pressure, required to pull 1200 cfm through a 7" smooth-walled pipe, with a plain end.

THAT assumes ZERO outlet loss. If there were 2" outlet loss(filters), the operating point of the blower alone, would have to be even higher, by 2". You'd have to have 4.274" friction loss. Velocity pressure would stay the same, since that's the same volume flowing through the pipe. Total operating pressure, would HAVE to be 5.533"sp for the blower, MINUS the 2" loss for the filter(outlet), you're back to 3.533 at the inlet.

"Direct-drive" blower, means exactly that. It's NOT a belt-drive. If the guy is telling you that the filters ADD 2" sp, instead of "INCLUDED" in the 1200 cfm rating, then this dc would be matched by a $200 Asian 1 1/2 hp dc. Frankly, at $2500.00, I kinda doubt that. If it were as you stated, you'd be pulling 1000 cfm according to the chart. That's at the inlet, no pipe. You couldn't even use 7" pipe on that dc, because you'd already be below 4000 fpm. (approx 3750 fpm)

Just think for a second. FORGET the 2" filter pressure drop, forget the 6" pipe resistance. Just look at the blower. Run the Beacon Engineering calculator, and you tell ME, what you see.

By the way, that 2" pressure drop at "the filter", means "total outlet resistance. Those guys use a smaller diameter pipe at the blower outlet, to convey waste to the top of the filter. That's why the pressure-drop number is so high.(E-series)

The Belfabs, use no such outlet restriction. That's why they claim a 30% performance increase over the competition.

PPS, You should have asked them about the impeller diameter.

[Allan Johanson]

Bob,

You're asking the wrong person. Since you don't seem to understand what's going on I suggest you talk to Kraemer yourself. Ask them whatever questions you want. However I think you're being very unfair to them when you're saying a $200 DC can perform similarly though. That isn't right.

If you really want to start understanding this topic you should buy yourself some testing gear. Just buy some gauges and a pitot tube and start testing things in the real world. Theory can only take you so far, then reality kicks in and really messes things up!

FYI, I've found the 0-2" Dwyer magnehelic gauge is great for the vast majority of testing. However, the 0-10" is great for SP tests and at times when you have very high airflow and the 2" gauge can't handle it. The pitot tube to buy is the Dwyer 167-6. Maybe $250 CDN should cover it for the pitot tube and the two gauges. Or you can go digital. Sweet.

This thread has been diverted enough so please create a new thread if you want to continue this topic. Ed wants to know what kind of cyclone to buy and it won't be a Kraemer.

Cheers,

Allan

[Bob Dodge]

Allan, you've skirted the issue again.

You said that the Kraemer's blower only, is pulling 1200 cfm, and that the filter, reduces that to 1000 cfm. According to your logic, you're saying, that $2,500.00 dc is only capable of pulling 1000 cfm with a 7" intake, when the filters are installed. That doesn't even get you 3800 fpm velocity in that 7" inlet. You couldn't use a 7" pipe on it, according to "your logic" despite the fact it has a 7" intake.

A $200. Asian dc, can pull over 800, with a 5" inlet.
The Delta 850, 1 1/2 hp, pulled 895 cfm. 6" inlet, 11" impeller.

http://www.rd.com/americanwoodworker...Collection.pdf

Care to explain "your conclusion"????

Bob

[Cecil Arnold]

Bob and Allen, while you both appear to be knowledgable in the subject, might I suggest that the discussion has reached or soon will reach the level of a public Pi--ing contest and might better serve those of us who are interested in the subject matter if your difference in opinion were discussed in a less public forum, such as MPs of e-mail. I came to SMC after watching another forum degenerate from woodworking information into political super egos and would hate to see the same thing happen at SMC. Thank you.

[markus shaffer]

Ed,

A lot has been posted here regarding CFM, pressure drop and the such. I did a bit of research before I bought my cyclone (2 hp commercial Oneida) and most of it gave me a headache. There is a wealth of information out there and no one can refute the benefits of the research that Bill Pentz made regarding this topic. While I will always encourage people doing their research, I just wanted to get the right machine and get on with my work.

I think at the end of the day, we all really do want to buy the right tool and not have to replace it after some time due to it's inadequate performance. This is why I decided to go with Oneida. They build dust collection machines and that's it. Their ductwork engineers did the layout for me and made sure that I would have a machine that would not only be sufficient for the shop I'm in now, but also for what I'm likely to grow into. I was not pressured to buy something more expensive than what I needed even though I made it known that I was more than willing to spend more if I was convinced I ought to. The service I recieved from Oneida was among the best I've gotten in the woodworking industry.

That being said, the performance of the machine I have is pretty amazing. My shop is fairly small, but I've stuffed a couple big machines in here. There are two gates open on my system all the time, one 5" and one 3" both going to my saw. I can open a 6" gate to my 20" planer leaving the two aforementioned gates open and still more than enough suction to capture everything the planer can throw out. Even when running a 20" inch wide board through it. Fit and finish of the machine is excellent.

Overall, I would say that my time was better spent going with the Oneida because the system and service were pretty all inclusive. I didn't have to buy or borrow anything to install it. I didn't have to fabricate any parts. It came in several boxes via FedEx ground, everything was well packed, everything was there and it went up relatively easy. To me, that was the most important thing. I wanted a product that had the least amount of headaches and that I was sure would be a good investment. I think that's what I got with Onieda. I'm not saying that you can't or won't get that kind of product and service with any of the other companies, but I believe you are guaranteed that with Oneida.

-Markus

[Jim O'Dell]

I have read till I am about to explode!
snip

So, Ed, have you made your decidion yet????? Or have you just pulled a sheet over your head and wished we'd all go away??? ;-))))
There has been some good info here, and like I said originally "...this is a great time to be in the market for a cyclone. There are several really good options." I think it will boil down to which color you like best... green, white, yellow, or none, and which one hits the price point you are looking for. Good Luck, and let us know when you have it coming! Jim.

[Bob Dodge]

Hi Jim,

I agree with you about "a great time to be in the market", and let me add, for dc's in general. Informed consumers are driving the demand. A tip of the hat to Bill Pentz in that regard.

I'm sure either the Oneida or the new Grizz would make excellant choices, as would a shop-built Pentz cyclone. For the faint-of-heart, perhaps even a passive cyclone body (no motor), with a shop-made Pentz blower. All excellant choices.

Let me add one more to the mix for the budget-concious. The new 2 hp Delta 50-761, single-stage. This appears to be a radical departure from the previous crop of consumer-grade single-stage designs. Gone is the choked-down blower outlet, and this should be a very free-breathing design, balanced toward suction rather than amp-draw limitation. Very gutsy move by Delta.

That dc has all 7+" porting (inlet/outlet), along with a 12" impeller. Even the twin 1 micron filters offer low pressure-drop, with 41 sq.ft. of surface area. These are among the nicest filters I've seen on a consumer dc, rivaled only by some of the higher-end General Internationals. This will be a very strong performer indeed, and sells for $499. I'm told. Definitely worthy of consideration. Fit and finish of the entire new series, is excellant. I saw the 3hp and 5hp versions last year, at an industrial trade-show, just prior to public release. Very impressive.

Bob

[Mike Weaver]

So, Ed, have you made your decidion yet????? Or have you just pulled a sheet over your head and wished we'd all go away??? ;-))))
There has been some good info here, and like I said originally "...this is a great time to be in the market for a cyclone. There are several really good options." I think it will boil down to which color you like best... green, white, yellow, or none, and which one hits the price point you are looking for. Good Luck, and let us know when you have it coming! Jim.

Ed,
I'll second a "Me too!" sorta post - a great time to be looking and PLEASE let us know what you went with and when it's on its way.

Cheers,
-Mike

[Jimmy Tallent]

I dont no weather to step in here or not,but iv'e had a tempest cyclone for about 8 months hooked to planer & tablesaw,3 hp and 6 inch pipe, not had ANY problems at all. It keeps on hummin.