Commercial DC upgrade recommendation needed

[J.R. Rutter]

I just signed the lease on some commercial space and need to upgrade my DC. I have a decent sized mid-efficiency cyclone - 30" diameter at the inlet. I'm thinking that I'll need 3000 - 4000 CFM if I have a couple of guys working. Biggest air pig is a double drum sander that needs close to 2000 CFM by itself to prevent dusty boards coming out the back side.

I don't have much industry eperience, so any insight on what works well for solid wood processing would be very helpful. I use Oneida cartridge filters now, and am thinking of going to something like their inverted 4 x filter plenum with a 6 mil bag for the fines. To start, I was thinking of keeping everything inside, but running the duct so that I can relocate the cyclone outside with RAL into trailer at some point if needed. After looking at bin option$, I may stick to my 55-gal drum chip bins, but get extra drums and trailer them to the shavings place down the road once a week.

So some specific questions:

What type of blower has good combo of noise, airflow, and static pressure?

Is the modular approach OK, or should I try to finance a complete new system?

What has worked for you, and what would you change if you could?

[Brian King]

How about a big 15HP Torit cyclone system? I found this one. they are asking 5k for it. I'd gues they would let it go for 4k.
Email me if your'e interested. I think it;'s a model 30. It's rated 400 to 5600 cfm at 5 to 9 inches of vacuum.
Click on the link for more info from Torit.
http://www.donaldson.com/en/industrialair/literature/000984.pdf

[Jim Becker]

If you are already familiar with Oneida, you should include them on your short list...they do large systems sized where you need for the new space. In fact, there's one at our local community college. Cyclone and blower are mounted outside and the filters for return air are inside. Additionally, there are other types of systems that you often see in industrial situations. Woodshop News this past week had a very large list of dust collection vendors.

[lou sansone]

wow ... 30" diameter at the inlet! Somehow this sounds like more than a "mid-sized" unit. What HP is the unit you are currently running? Just a wild guess that a 30" diameter pipe would be in the range of 15,000 cfm.. am I missing something here ? When you say 30" inlet, do you mean a 30" diameter inlet pipe into the cyclone impeller or a 30" diameter cyclone ?

lou

[Bob Dodge]

Hi JR,

I presume your bresent blower is a 10 hp, on a 30" diameter cyclone. If so, you probably have a 12" inlet. That would put you roughly in the ballpark of 3000 cfm at 10"sp, to 4500 cfm at 5"sp. Depending on how long your runs are, you should be ok with your present blower. With 2000 cfm at that dual-drum sander, and a total of 1600 cfm from two other machines operating simultaneously along with the sander, you're looking at 3600 cfm at roughly 7"sp-7.5"sp.

If you decide to run a larger dc indoors, you'll have to check into the NFPA codes (fire prevention). I believe all self-contained indoor dc's require explosion doors at 5000 cfm and above. There is also a rule for mechanically-fed sanders.

You mention a "quiet blower". The only one I know of off-hand, is the Belfab "Hummer Series" blower. They use an extra-large diameter fan-wheel, at half speed, 1725 rpm, which reduces noise significantly. The 10 hp model, pulls roughly 4200 cfm at 8.5"sp, and 2750 cfm at 10"sp. Here are the performance curves.

http://www.belfab.net/perf-dw.html

The Pyradia/Belfab guys deal strictly with industrial systems. They can tell you all the ins and outs of those systems, fire-codes etc, and they're an absolute pleasure to deal with. I'm running a pressure-check on a small system in Montreal, on Tuesday or Wednesday of next week. One of the engineers from Belfab, is accompanying us for the test. I'll mention your proposed set-up. Pierre Morin, the production manager at Pyradia/Belfab, is also a great guy to speak with. I may be having lunch with Pierre early next week, and could arrange for him to contact you. Don't worry about Pierre trying to sell you something. "Pushy" is the LAST thing you'd assosciate with Pierre.

That 15 hp Torit that Brian showed you, is an absolute steal at that price. I priced a re-furbed 2hp Torit model 16 a while back, and they wanted over $3500. for that unit.

I won't comment too much on your filtration set-up, other than to say that outfits like Torit and Farr, tend to use bag-type filters on their cyclones, and that's despite the fact that Torit is probably the world's largest industrial filtration manufacturer. That includes cartridge filters. Torit uses about 200 sq.ft. of total filter surface area, on their 10 hp cyclone. (8 x 25 sq.ft. needle-felt bags)

Farr, at the request of a furniture manufacturer/client, installed cartridge filters in a bag-house dc. They had to use fine-mesh "over-bags" to cover the filters, to prevent them from clogging. Without pulse-jet cleaning, I'd stay away from cartridges, especially with a large dual-drum sander. I'd probably look into Beane*Bag filters for the cyclone. Pierre, can tell you more about those. Air-permeability is outstanding, at 65 cfm per sq,.ft. 1/2 micron capture, at 99.9% efficiency. Can be washed up to 6 times, and retain 90% of original efficiency. Loop-pile knit, for enhanced particle release/ ease of cleaning.

http://www.beltechengineering.com/Products/bean.html

http://www.donaldson.com/en/industrialair/literature/000984.pdf

Good luck with the new shop.

Bob

[Alan Turner]

JR
One thing you might want to consider if you mount the unit on the exterior is a rotary air lock. You need back pressure from the cyclone to the "barrel", and hence a good seal is critical, or the filter (baghouse) will fill immediately (I was told). If you are running a big unit, then a 55 gal. drum will fill quickly, esp from the planer and jointer. A rotary air lock device supplies this back pressure and allows a gravity drop into a bin or trailer. The seal is at the rotary device. I am trying to source one now (a used one) for my as yet unmounted 15hp Torit cyclone. For my application, I am told that I need a 12" inlet to the lock. I will be running a 16" dia. main, and the cfm at the inlet is said to be 5800 cfm.
This is a next summer's job. I am thinking that I will mount the cyclone on the side of the building at a height which permits a trailer to be placed under it.

[tod evans]

j.r., bob gives you very good advice about stearing away from the cartridge filters. they are designed for small units. i poor-boyed my system out of salvaged parts but i did go with the good bags for return air. i don`t know of any "quiet" blowers that really move air but the one bob spoke of sounds interesting. i do know where there is an old 75hp 30" fan, i also know of a 15 hp 20" backwards inclined fan if you decide to build a new system...tod

[Jim Becker]

Here's an example of a 15hp belt-drive system (http://www.oneida-air.com/products/systems/15bd/main.htm) from Oneida...similar to the unit at my local community college. (I don't know if they have the 15hp or 20hp system)

http://www.oneida-air.com/products/systems/10bd/images/main.jpg

[Doug Jones from Oregon]

Since you are in Bellingham, I would suggest you check out this auction coming up soon just a few miles south of you. They list several systems that you would save huge money on, biggest cost usually being dismanteling and transporting to your location and reassembly.

www.murphyauctions.net

Look for the Maxon entry.

Good luck on the new shop! Drop me a line when you're set up and perhaps I could visit when visiting my folks in Mt. Vernon.


Doug

[Bob Dodge]

Hi JR,

Just a few more thoughts to share.

If you want to keep costs down, and you want to use your existing blower, you could set up in "push-through" mode, but that will depend on your fan-wheel. You wouldn't want to do that with a back-inclined fan-wheel, only a material-handling radial-blade fan-wheel will do in that application.

Regardless of how you set up, you could easily make a reasonably compact bag-house for a filtration stage. You'd need some tube-filters, some capped thimbles to mount one end of your filters, and a simple "shaker" mechanism.

Let's say you're using 6" diameter tube-filters, and each is 5 feet tall. Each "tube" will have a surface area of just under 8 sq.ft (7.85) You can quite easily squeeze four of those, into a 1 sq.ft. area, for 32 sq.ft. of filter surface. How close those filters are to each other, will depend on whether you want to flow "outside/in", or "inside/out". If you flow outside/in, you'll want a bit of space between those filter-tubes, to allow waste to drop through the "shaker" mechanism base.

Let's build an out-side/in shaker set-up. Let's assume your blower is mounted before that unit. Picture a cabinet, about 30" deep (front-to-back), by 5 feet tall, by 5 feet wide. Under that cabinet, the bottom slopes like a rectangular funnel, to your waste bin. That need not be particularly large, since you're only dealing with cyclone "blow-through".

Now, in the top of that cabinet, you have 6" ports. Those ports allow clean air, back into your shop. Hang your tube-filters from those. The other end of those tube-filters, will go to the "shaker" mechanism. You'll only need "end-caps" to fasten your filter-tubes to the shaker.

The "Shaker", can be a simple unit, fabricated from 3/4" pipe. Picture 4 pipes, running parallel to each other, and about 4 1/2 feet long. The ends of those pipes, are fastened to two short pipes, running perpenducular to those. This would look sorta like a "tray", or a wide letter "H", but with 4 cross-bars. Those two "end" pipes are 30" long, and the four "cross" pipes, are 4 1/2 feet long. The ends of those end-pipes, will ride in a small track, inside that bag-house cabinet. They'll only require a short travel distance, side-to-side, maybe 3" or so.

The "cross-pipes" can be 6"-7 1/2" apart. On the top surface of that "grid", fasten some filter "end-caps". They can be screwed right into the pipe. Now you can fasten the bottom-end of your filter-tubes to those end-caps.

We now have an array of tube filters, 4 rows deep, by perhaps 8 rows wide. 32 tube-filters x 7.85 sq.ft. per filter = 251.2 sq.ft. 9 rows, would give you roughly 283 sq.ft.

Now, that lower shaker "grid", has spacing of 6"-7" between the pipes, easily allowing shaken waste to drop out. That grid, needs only a few inches of travel, side-to-side, and you can use rubber "bumpers" on that grid, along with a few springs. A simple cord running from the shaker grid, to the outside of the cabinet, and a pull-handle, to manually operate the "shaker". "Bump-bump-bump", and you dislodge any accumulated dust-cake. It falls through that pipe-grid, into the waste funnel, and collection hopper below.

You could easily make that cabinet from MDF, with two front doors for servicing your filters. You'd want to seal those doors, but you'd be dealing with very low pressure in that unit. Should be quite easy to do.

A few sheets of MDF, some pipe, and a bit of hardware (hinges-springs-cord) and you're down to the cost of those tube-filters.

Before determining the cabinet size, I'd start by choosing the filters. They come in many diameters and lengths.

With 3600 cfm, and 250 sq.ft. of filter, your interstitial velocity will be 14.4 fpm.

If you go with 32 6"x72" filters, you can get a total surface area of 310.5 sq.ft. With 3600 cfm flowing, your interstitial velocity will drop to under 12 fpm.(11.94)

Depending on how you size that unit, you could do away with the cyclone altogether. If you set-up in "push-through" mode, no further modifications are required at the bag-house. If you set-up in "pull-through", you'll have to "top-mount" the blower, and that will require an additional air-chamber (plenum) at the top of the bag-house.

Hope that helps, Bob

P.S. Here are a few interesting links/pics, to help you finalize a design.

http://www.donaldson.com/en/industrialair/literature/000985.pdf

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

[J.R. Rutter]

Thanks all!

Brian - Thanks, the Model 30 is one unit I was considering, I might get in touch with you later if I go that route.

Jim - I am familiar with Oneida (got a quote from them last week), but they are across the country, and the 15 HP system fully loaded came in at over $10K.

Lou - Current cyclone is 30" diameter, sorry this was not clear in hindsight. Inlet is 10".

Alan - I did just see an 8" RAL on woodweb, which would fit my current cyclone, I'm just not sure yet what direction I want to go. Outside with trailer would be ideal, but there are some potential tenant issues and parking access.

Bob - Yes 10 HP blower, BUT it was designed for exhausting a single aluminum billet saw to the cyclone via 6" pipe. At 19" fan diameter, it has goos static pressure, but limited CFM due to restricted outlet (I did enlarge the inlet to 10" when I installed it in my current shop). I got an e-mail from a Monsieur Crocteau at Belfab on their nice bin setup from the Hummer line, which you pointed me towards in a past thread.

Seems like most industrial setups use cloth filter fabric, as you mention. The cartridges do require manual blow down every couple of days, which is not fun. And I managed to explode one a few months ago. Seems like Donaldson/Torit is not pushing the cyclone anymore. Is this due to the technology being surpassed by the bag house types, or some other reason?

I do generate a pretty big volume of waste - up to about 4 drums a day when rough milling. I just read the Woodshop News article today, and identified with the millworks shop that went from 4-barrel cyclone to RAL baghouse (and they emty that new trailer 2x/day!!!).

I'll study the links to baghouse construction to see if that might be worth doing. The Hummer system is also very nice, but expensive.

Thanks everyone for taking time to help out!

[Bob Dodge]

Hi JR.

OK. Seems like we're narrowing this down somewhat. Is your blower made like the large blower to the right in this pic?

http://www.general.ca/pagemach/machines/0general/no1no4a.html

This would have been a push-through set-up to the passive cyclone. What size inlet and outlet do you have at the cyclone? With a 6" blower outlet, and a 19" fan-wheel, velocity must have been quite high, which is quite typical for metal-processing machinery blowers. The high-density waste requires that extra high velocity, for adequate suspension in the pipes. They generally operate at 4500 fpm and up. 4500 for the lightest waste, to whatever velocity that particular machine's process requires.

In a woodworking application, that 6" pipe would normally be operating at around 4000 fpm, and require a 1 1/2hp-2hp motor. Actual brake-horsepower would be roughly 1.2 bhp. Doubling the airspeed results in a "squaring" of static pressure. The horsepower requirement, is then "cubed". Example; we doubled velocity, so we cube that value,2x2x2=8 times the original bhp. 8 x 1.2bhp= 9.6 bhp. That's why your blower has a 10 hp motor.

As to the filters, yes, the industrial dc manufacturers go with needle-felt filters, and the Beane*Bag fabrics. They're more suited to handling coarse/dry waste, such as you'll find in woodworking processes. Air-permeability in the quality filters, generally runs 55-65 cfm/ sq.ft., with filtration efficiency to 1/2 micron/ 99.99%. The filters of course, have to be properly sized for the airflow.

While we woodworkers tend to think of dc's and filters in a woodworking context, industrial filtration runs a very wide spectrum of manufacturing processes. Many cartridge filters, are designed for entirely different processes, such as dealing with vapours, mists, and smokes. It may be entirely unsuitable to choose a cartridge filter, simply because of a large surface area. That cartridge may actually be intended for use with welding vapours for example, and the tight pleats of such a cartridge, will quickly load with fine wood-dust, and be difficult to clean to sustain airflow. Those that are designed for particle loading, may have a reduced surface area, with wider pleats, and perhaps a surface treatment of some type. Here are some surface treatment examples.

Under the heading "products", click on the words "Mantes, Rhytes,Kleentex" etc

http://www.testori.it/frameprodotting.html

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You said;

"Seems like Donaldson/Torit is not pushing the cyclone anymore. Is this due to the technology being surpassed by the bag house types, or some other reason?"
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The cyclone, is the least-efficient type of dust-collector. It consumes more energy to operate, than single-stages, or bag-houses. The higher-end stand-alone cyclones, tend to go with caged back-inclined fan-wheels, and this dramatically reduces energy costs, and results in higher static efficiency. These blowers are very expensive. They can only be used in a "clean-side" application. That allows them to be used in pull-through cyclones, or a baghouse. On the cyclone, the blower requires periodic maintenance, due to loading at the blades (fine dust). Left unattended, it could cause an imbalance, and premature bearing failure. On a bag-house, the air is pre-filtered. Less maintenance required, lower maintenance expense, longer blower life.

Also, the bag-house doesn't require a pre-separation stage. It doesn't have the same resistance as a cyclone, and you can use a smaller motor/blower, for the same cfm. Result, lower energy costs per cfm.

Space-wise, a 10 hp 30" diameter cyclone requires about 14 feet of minimum ceiling height. That's for a 3000-4500 cfm capacity. A similar capacity baghouse, can be far more compact.

The Belfab dc that I showed you, with the tilt-trucks for waste-handling, combines the features of a single-stage dc, with a low-cost material-handling fan-wheel, and bag-house type filtration. Rather than having the filters flowing outside/in, they're flowing inside/out. A unit such as this one, with a 7 1/2 hp motor, is under 11 feet tall, and flows 3500 cfm at 6" sp. and incorporates a manual shaker.

http://www.belfab.net/jnbm-op.html#specs

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J.R., There's no reason why you couldn't use your existing blower, to handle "some" if not all your shop-machines. Mind you, if your blower looks like that big cast-iron General exhauster, then modifying the outlet, is out. You could increase pipe diameter right at the outlet however, and decrease the inlet slightly, to possibly 8"-9", serving two machines with 6" pipes. Your 10 hp motor would be "idling". Might not be very efficient, but a lot cheaper than buying a new blower.

If you used it solely for that big sander you mentioned, you could even use a couple of inexpensive single-stages, for the other two machines you mentioned. Wouldn't even require ducting. Direct hook-up. At $499, this 2hp model has great filters, with oversizing to 41 sq.ft, and twin waste-bags, for extra-long run-time between emptying. It should easily pull 1000+cfm at 4" sp, with a ten foot pipe, 6" diameter. Filters are the best I've seen for this class of dc. Same quality as the larger 3hp and 5 hp models.

http://www.deltamachinery.com/index.asp?e=136&p=5816

The 3hp and 5 hp models in this same line-up, would easily handle two large machines running simultaneously. These are BIG dc's. Just under 10 feet tall. I saw those just prior to public release, and was very impressed with filter-quality, as well as overall fit and finish. Not sure what the pricing is on those however.

http://www.deltamachinery.com/index.asp?e=136&p=5819

Good luck, Bob

[lou sansone]

I am glad that bob finally bought up the fine pleat / wide pleat issue. I see a lot of cheepy DC with fine pleat filters that I am sure are going to plug right up once they are used for ww dust. take a look at the oneida and you will see much wider pleats that are specifically made for wood dust. great link that you provided ..

lou

[J.R. Rutter]

Wow, Bob - Thanks for the additional info. I feel like I've gotten a great homework assignment - one that will give me a good understanding of this issue instead of a pat answer. Thanks again. My blower is heavy plate steel with radial impellar. It had a removeable inlet plate, so I made a replacement to go from 6" inlet to 10". The outlet is about 4.5" x 6" and connects directly to my filter plenum.

I do run the Oneida filters, which are coated and have wide pleats. Still, they are recommended for coarse dust rather than sanding dust. Harder woods in particular (no pun intended) create an incredibly fine powder that raises the back pressure quite a bit. I had a plastic waste bag pop off the other day while sanding - not fun!

I am thinking that a shop-made plenum similar to Oneida's inverted setup might be the way to go if I stick with the cyclone idea. The base has a funnel shape, with tube filters rising from it, air flow from inside-out.

Oh, and Douglas - Thanks for the info. on Maxon. The SCMI rip saw might be worth the trip down there.

[Bob Dodge]

JR,

While bolting the blower to the plenum reduces the outlet pressure somewhat (no pipe to deal with), it'll still have a "shot-gun" type of effect. Any waste carried through to the blower, will enter that plenum at very high velocity. At 2000 cfm, you're looking at roughly 11,000 fpm through that outlet.(over 120 mph). It wouldn't surprise me a bit that you'd pop a bag off. Those filters are loading-up too much due to turbulence.

You can easily re-balance that outlet velocity, and use your present small blower-outlet to your advantage.

Place that blower closer to your cyclone(if you're using pull-through), and run a short, large-diameter outlet pipe, say 8"-9" diameter, then add a 8x8x8 wye or a 9x9x9 wye, and run twin 9" pipes into your filter plenum. Entry velocity at the plenum will be 2265 fpm for each pipe. If those pipes are descending to the plenum, or very short, you'll have no problem with transport velocity, especially with sanding dust. You could even increase those diameters, or re-double those pipes with wyes on each. With 4x 9" pipes, you'd get 1132 fpm at the plenum entry. Ideally, you want that plenum operating at very low velocity. That includes interstitial velocity through the filter media. Entry velocity will be 1/10th what it was, or roughly 12 mph.

Bob