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Thread: Clearvue is releasing a new metal cyclone, the Pentz EF5

  1. #91
    Dave, if the CV Max & the new Pentz clone are exactly the same they are probably using the same blower, same fan and the same intake and exhaust size ports. There’s only a few ways to make air move faster... using the same design.

    -More RPM,
    -More fan diameter,
    -Larger inlet and exhaust,
    -More horsepower (measured in kilowatts)
    -Larger filters (or less filter resistance)
    -More efficient fans (blade angle/displacement and overall weight)

    Changing any of the above could directly require changes to more of the above.

  2. #92
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    Matt, to my knowledge there are no performance differences between the old Max and the new steel system. Maybe a little if the intake has changed but only a little. The upgrade is in the materials used, not the performance. There was some talk years ago about a larger unit but that hasn't happened yet. Dave

  3. #93
    So does anybody have a CV-Max fan curve chart to apply to this thread???? Or the new Pentz clone? Maybe even somebody could start a new thread (or I’ll start one, when I get my numbers probably in a week.)

  4. #94
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    Quote Originally Posted by Josh Kocher View Post
    Joe.

    Thanks for the detailed post... but you didn't answer my question.

    A larger main supports less of a loss and more CFM. If you have the intake/airspeed/system to support it why wouldn't you?
    Take my Felder 700 series sliding saw, the actual port under the blade shroud is equivalent to a 3.5" diameter round port. With a typical collector I will be lucky to pull more than 350 CFM through that port, no matter if I have 6" or 8" or 10" mains. If I am pulling 350 CFM through that port, I am also pulling 350 CFM through the duct. That 350 CFM in a 4" duct will flow at a velocity of 4011 feet per minute. In a 5" duct that same 350 CFM will flow at 2567, well below the minimum 3500 feet per minute to prevent pooling. Now step up to a 6" duct, 1783 feet per minute. An 8" duct will only move at 1003 feet per minute. That's why. The science does not allow a collector of normal suction pressure to move enough CFM through small ports to keep the airflow high enough. For grins I used Bill's spreadsheet to run the numbers for a 3.5" port to have a velocity of 4000 feet per minute in an 8" duct. The collector would need to generate 37.12" WG of suction pressure at 1400 CFM. Most 5HP designs can pull only 15" at zero CFM. At 1400 CFM they can only generate 2-3" WG of pressure. I know of now commercial WW dust collector of any HP that can pull that much pressure at that CFM. A Rigid shop vac and pull like 100 CFM at 99" WG but that's a shop vac design point and not a dust collector.
    Last edited by Joe Jensen; 09-24-2018 at 12:49 AM.

  5. #95
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    If you run a typical 5 hp system and need an 8" port for a large machine- shaper for instance with two ports - you need to design the 4" gates so two are always open. The velocity in the 8" might still be marginal depending on the impeller. My high pressure impeller pulls 11000 fpm through a 4" port and opening the second slows it to about 9000 fpm. The challenge with hobby systems and large or old machines is to cover the range of machines used. I experimented with BC and radial impellers before I found a 15.75x6" radial that works for me. Dave

  6. #96
    So again. It was a "broad statement"... really, you are talking about your needs and your saw.

    Your configuration doesn't support that...

  7. #97
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    Quote Originally Posted by Josh Kocher View Post
    So again. It was a "broad statement"... really, you are talking about your needs and your saw.

    Your configuration doesn't support that...
    Josh, what are the actual machine port sizes on your machine? Here is my shop:
    - Felder Saw, 3.5" port in cast iron blade shroud. Not possible to enlarge.
    - Felder shaper, less than 2" port in the cast iron support under the table which is not possible to enlarge and a 5" port on the back of the fence.
    - Felder bandsaw, the port is just into the base of the machine, I've modified to accept a 6" duct
    - SCMI 12" jointer, I've modified to accept a 6" duct
    - PM100 Planer, great 6" port from the factory
    - PM 24" dual drum sander, two 4" ports connected to a 6" duct, not sufficient and I will modify to two 5" ports
    - Dewalt 14" RAS, I have a 5" port to the rear of the blade and a 2" port to the top of the cast aluminum blade guard. It's not modifiable but the dust collection from the rear is good.

    If your tools just have a hole in the base and collect dust in the cabinet, put a bigger port in the base. I did that with my PM66 table saw. Make sure you have enough open space to allow that much air to flow.

    I have been harping on this because 8" ducts don't flow well when connected to a single 4" machine port. People see pro shops with big main branches and it supports the general notion that bigger must be better. Pro shops usually have multiple worker running at a the same time. If you run 8" duct you need it fed with TWO 6" branches that flow freely or you need to have enough gates open to enough machines. Lastly I am an engineer who has studied this and I've tried unsuccessfully to explain two semesters of a 3rd year engineering class in a couple of posts on here. But clearly the interwebs are more correct for you.

  8. #98
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    Most of us often run our DC system with 4" hoses on even smaller machine openings, knowing that the velocity in the main duct will be less than optimal. There might be a small buildup of debris until we use another machine with larger piping and a higher air flow that will scrub the ducts of the previous buildup. It is the nature of the beast. You design the system, including the main duct, for worst case high airflow demand. In my case 800-1000 cfm on my TS with a 5" bottom opening and a 3" top opening on the Sharkguard. You design the main duct to flow about 3500-4000 fpm at that worst cast scenario. A higher velocity just wastes energy on friction and will eventually cost you airflow at the last machine on the run. I will say it again, the sweet spot for that 800-1000 cfm airflow is a 7" pipe. With just my TS blast gates open, I am flowing 950 cfm at 5.3" of suction. 7" pipe velocity at 950 cfm is 3555 fpm, just about optimal for a horizontal run. BTW, there are several qualified engineers responding to this thread that have sat through many classes on flow dynamics, this one included, and have made good use of that education working with and designing piping systems for many years.

    A watermain is designed to flow the maximum daily demand plus an added fire flow while maintaining a minimum pressure at the hydrant under fire flow use, usually 20 psi. As a result normal pipe velocities are too low to transport sediment. That is why you will see selected fire hydrants being used to flush sediment out of the system often on a yearly schedule. Sound similar to a dust collection system design and use?
    Last edited by Ole Anderson; 09-24-2018 at 12:21 PM.
    NOW you tell me...

  9. #99
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    Quote Originally Posted by Ole Anderson View Post
    Most of us often run our DC system with 4" hoses on even smaller machine openings, knowing that the velocity in the main duct will be less than optimal. There might be a small buildup of debris until we use another machine with larger piping and a higher air flow that will scrub the ducts of the previous buildup. It is the nature of the beast. You design the system, including the main duct, for worst case high airflow demand. In my case 800-1000 cfm on my TS with a 5" bottom opening and a 3" top opening on the Sharkguard. You design the main duct to flow about 3500-4000 fpm at that worst cast scenario. A higher velocity just wastes energy on friction and will eventually cost you airflow at the last machine on the run. I will say it again, the sweet spot for that 800-1000 cfm airflow is a 7" pipe. With just my TS blast gates open, I am flowing 950 cfm at 5.3" of suction. 7" pipe velocity at 950 cfm is 3555 fpm, just about optimal for a horizontal run. BTW, there are several qualified engineers responding to this thread that have sat through many classes on flow dynamics, this one included, and have made good use of that education working with and designing piping systems for many years.

    A watermain is designed to flow the maximum daily demand plus an added fire flow while maintaining a minimum pressure at the hydrant under fire flow use, usually 20 psi. As a result normal pipe velocities are too low to transport sediment. That is why you will see selected fire hydrants being used to flush sediment out of the system often on a yearly schedule. Sound similar to a dust collection system design and use?

    I could not agree more...joe

  10. #100
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    This is better than a sharpening thread. It is pretty well known now amongst those who follow these things that GOOD entry design of the port will substantially increase air flow in any duct so figures given for duct flow can be influenced and are not written in stone.
    Chris

    Everything I like is either illegal, immoral or fattening

  11. #101
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    Quote Originally Posted by Chris Parks View Post
    This is better than a sharpening thread. It is pretty well known now amongst those who follow these things that GOOD entry design of the port will substantially increase air flow in any duct so figures given for duct flow can be influenced and are not written in stone.
    Like this 4" port in my G1023 enlarged to 5" with a bell mouth inlet?
    Attached Images Attached Images
    NOW you tell me...

  12. #102
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    Thumbs up

    Ole you're a follower!

  13. #103
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    Is that in Aluminium? Very nice. It is subtle stuff like this that makes a good system.
    Chris

    Everything I like is either illegal, immoral or fattening

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