Hi all.
I'm looking for some help replacing my P&J dust extractor (3kw / 4hp). I can't stop it from leaking dust into my workshop. It's leaking from the hopper, where it mates with the main extractor body and I don't trust the filter system.
I've got about £3-4k to spend on a new system and have serval options. My preferred choice would be a Donaldson Down Flo, but then I wake up.
Your average Jet, Axminster, Laguna, iTech etc.. will not have enough power for my needs but my needs aren't that great per say. I only use one machine at a time, so I'm not 'industrial' but I do have some pretty big kit, which pushes me into the more 'extreme solutions' department.
My initial idea was cut the tower off my P&J, cut off the hopper shoot and cap both remaining holes. Then cut the end off the unit and connect a plywood box section with 4 cartridge filters. That system will then have its own bucket connected by gasketed clip ring. Something like this. (pic 3)
There are many revisions I can make to the design but that's the basic idea. My concern with this and why I haven't gone ahead, is the issue with the cartridge filters.
I ordered some custom ones from Cavendish but I think they are far too tightly pleated for wood processing. They say they will work but I can see them getting clogged in about 1 second. I also have different machines attached to the system.
1x Planer/Thicknesser
1x Bandsaw
1x Panel Saw
1x Wide Belt Sander
The m2 of the material of each cartridge is about 35 m2 (totaling 140m2) so huge amounts of nano coated, anti static real estate. Far too much actually.
The trick is how do I stop the bigger bits of material going into the filters and clogging them? I can add baffles but not sure how to do that. Perhaps one low cut panel going across the first two openings that causes the heavier particles to get stuck on and the lighter ones to flow over the top? That's kinda how they work but will need some fine tuning. That could be a horrendously fussy process, unless I get lucky.
The second option is to buy a cyclone system. I've been researching them but they are difficult to get your head around. With a normal single stage positive system, usually more power means more suction, means better (ala Jeremy Clarkson). Cyclones are a very precisely controlled system with the exact size of ducting and amount of ducting. Even throttling some pipe runs to balance them at the cyclone.
I've done a LOT of research into flow rates, velocity, pascals and static pressure but being pretty thick, it's not natural for me to understand such things.
I'm aware that the system has to be set to your most greedy machine (including ducting).
In this case, that would be my Fleder Bandsaw, which has 2x 120 ports.
Felder rate the ports as follows
20.32 m p/s (4000 FPM)
814 m3 p/h (500 CFM)
917 Pa (3.7"w).
There are two of them which is as follows
20.32 m p/s (4000 FPM)
1628 m3 p/h (958 CFM)
1834 Pa (7.4"w)
This means that I need a motor/fan that can achieve 1,700 m3/ph (958 CFM) and a minimum of 1834 pascals (7.4 WC). This is all without ducting so if I use a calculator I can measure the required motor with ducting.
Using the Pentz calculator I add the ducting and cyclone into the equation.
Ducting 1.5 mtrs, 2 x 90 degree bends at 120mm, a Y shape 2 x 120, 1x 150mm, joining onto 3 mtrs of 150mm ducting into the cyclone.
This comes to:
Flow = 1628 m3/ph (958 CFM)
Pressure = 4869.5 Pa (16 WC)
The problem is, I'm having trouble finding a motor with a power curve that can keep up to Metric: 1628 m3/ph - 4869 Pa:
Imperial: I958 CFM - 16 WC.
Here is a power curve for a 5hp 4kw motor which should have more than enough power but @ 958 CFM (1628 m3/ph) , the WC is about 11 (2739) Pa), which is far too low.
I can lower the WC (Pa) by increasing the ducting to 180mm etc. but the ports on the Felder are still going to be 120mm. Ultimately the ports are too small, or the extractor to use on it, should have much more pressure over volume. So more like a supe'd up shop vac.
I don't want to have to buy two extractors if I can avoid it but a machine to power the extraction here, is going to be huge and very expensive to run.
If anyone can help, it would be much appreciated.
I'm looking for some help replacing my P&J dust extractor (3kw / 4hp). I can't stop it from leaking dust into my workshop. It's leaking from the hopper, where it mates with the main extractor body and I don't trust the filter system.
I've got about £3-4k to spend on a new system and have serval options. My preferred choice would be a Donaldson Down Flo, but then I wake up.
Your average Jet, Axminster, Laguna, iTech etc.. will not have enough power for my needs but my needs aren't that great per say. I only use one machine at a time, so I'm not 'industrial' but I do have some pretty big kit, which pushes me into the more 'extreme solutions' department.
My initial idea was cut the tower off my P&J, cut off the hopper shoot and cap both remaining holes. Then cut the end off the unit and connect a plywood box section with 4 cartridge filters. That system will then have its own bucket connected by gasketed clip ring. Something like this. (pic 3)
There are many revisions I can make to the design but that's the basic idea. My concern with this and why I haven't gone ahead, is the issue with the cartridge filters.
I ordered some custom ones from Cavendish but I think they are far too tightly pleated for wood processing. They say they will work but I can see them getting clogged in about 1 second. I also have different machines attached to the system.
1x Planer/Thicknesser
1x Bandsaw
1x Panel Saw
1x Wide Belt Sander
The m2 of the material of each cartridge is about 35 m2 (totaling 140m2) so huge amounts of nano coated, anti static real estate. Far too much actually.
The trick is how do I stop the bigger bits of material going into the filters and clogging them? I can add baffles but not sure how to do that. Perhaps one low cut panel going across the first two openings that causes the heavier particles to get stuck on and the lighter ones to flow over the top? That's kinda how they work but will need some fine tuning. That could be a horrendously fussy process, unless I get lucky.
The second option is to buy a cyclone system. I've been researching them but they are difficult to get your head around. With a normal single stage positive system, usually more power means more suction, means better (ala Jeremy Clarkson). Cyclones are a very precisely controlled system with the exact size of ducting and amount of ducting. Even throttling some pipe runs to balance them at the cyclone.
I've done a LOT of research into flow rates, velocity, pascals and static pressure but being pretty thick, it's not natural for me to understand such things.
I'm aware that the system has to be set to your most greedy machine (including ducting).
In this case, that would be my Fleder Bandsaw, which has 2x 120 ports.
Felder rate the ports as follows
20.32 m p/s (4000 FPM)
814 m3 p/h (500 CFM)
917 Pa (3.7"w).
There are two of them which is as follows
20.32 m p/s (4000 FPM)
1628 m3 p/h (958 CFM)
1834 Pa (7.4"w)
This means that I need a motor/fan that can achieve 1,700 m3/ph (958 CFM) and a minimum of 1834 pascals (7.4 WC). This is all without ducting so if I use a calculator I can measure the required motor with ducting.
Using the Pentz calculator I add the ducting and cyclone into the equation.
Ducting 1.5 mtrs, 2 x 90 degree bends at 120mm, a Y shape 2 x 120, 1x 150mm, joining onto 3 mtrs of 150mm ducting into the cyclone.
This comes to:
Flow = 1628 m3/ph (958 CFM)
Pressure = 4869.5 Pa (16 WC)
The problem is, I'm having trouble finding a motor with a power curve that can keep up to Metric: 1628 m3/ph - 4869 Pa:
Imperial: I958 CFM - 16 WC.
Here is a power curve for a 5hp 4kw motor which should have more than enough power but @ 958 CFM (1628 m3/ph) , the WC is about 11 (2739) Pa), which is far too low.
I can lower the WC (Pa) by increasing the ducting to 180mm etc. but the ports on the Felder are still going to be 120mm. Ultimately the ports are too small, or the extractor to use on it, should have much more pressure over volume. So more like a supe'd up shop vac.
I don't want to have to buy two extractors if I can avoid it but a machine to power the extraction here, is going to be huge and very expensive to run.
If anyone can help, it would be much appreciated.
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