sploo
Somewhat extinguished member
Just checked: based on the size of the housing I'd guess maybe 13".
Who has achieved 1000cfm at their static machines (a la Bill Pentz).. if so, how?
- Thread starter Togalosh
- Start date
Help Support UKworkshop.co.uk:
http://www.freecalc.com/ductloss.htm
The link above is one pete ( inspector ) sent me a while back....
My impeller is aluminium! Mind you, I'd have to be unlucky to get metal going up the chute, i dont run iffy timber through the machines, so it would only be if a bit of metal were imbedded in a tree as it grew.....
The link above is one pete ( inspector ) sent me a while back....
My impeller is aluminium! Mind you, I'd have to be unlucky to get metal going up the chute, i dont run iffy timber through the machines, so it would only be if a bit of metal were imbedded in a tree as it grew.....
heimlaga
Established Member
This is the filter housing.
It contain four Dinair cartridge filters held with threaded rods against holes in the top. The rods pass through the U-bars on top. The air inlet is some 30cm above the bottom of the housing and a little below the closed end of the cartridges. This means that the lower part of the housing acts as a baffle where dust and stray chips coming through from the cyclone can settle on the bottom. The large door on the front is for cleaning or shifting cartridges. The small door near the bottom on the end is for raking out dust from the bottom of the baffle. The adwantage withhaving air pass from the outside of the cartridge inwards is that due to the tubular shape of the cartridge the folds are more open on the outside and hence much easier to clean without undue wear on the filter material.
I found almost this much proper dust ducting at one of the local scrap yards and only had to buy one bend and one piece of straight duct and the blast gates. The long hose goes out the door in warm weather. I found the hose on the beach when cayaking so it is a bit ugly. On the suction side there are spiral ducting and mostly home made blast gates but I wanted proper components on the pressure side as there dust will leak out through every hole.
Togalosh
Established Member
Thanks for the link to the calculator, very good of you... but man, now my head is spinning... gas pipelining is soo much easier than that ventilation. I will try it again when I've had more sleep.
Metal on aluminium strikes are easily done if you use your system to vacuum your floor or workbench. It seems nice to be able to just sweep your mess up to a drop & away it goes.. but no, it's fraught with danger too.
Togalosh
Established Member
Thanks.. Bill says minimum of 14" but it's on the right track.
sploo
Somewhat extinguished member
At the longest run from the motor+impeller I'd guess I would have had about 8m of ducting (up a wall, along the ceiling, and back down) and then 1m of 100mm hose. Even at that length it could "steal" a 1" (25mm) cube of wood and pull it along the ducting. Granted that system did not have a cyclone, which would reduce the flow quite a bit.
Togalosh
Established Member
heimlaga
Established Member
Exactly.
sploo
Somewhat extinguished member
Interesting. Are filters directional though? I suppose if it's already going through a cyclone then it's not like you'll be bombarding them with chips...
Inspector
Nyuck, Nyuck, Nyuck!
Industrial filters are designed to filter from outside inwards. Hobby DCs are inside to outside because it is cheaper to make and smaller. You can use them backwards but the filter media in many are layered or treated on the surface to shed the dust during cleaning cycles. You can specify the airflow direction if getting filters made and they will accommodate.
Pete
Pete
I'm asking myself same questions as @Togalosh but with slightly less urgency as my new workshop won't be ready until next year. Just got quote from DeAnn at ClearVue for shipping to UK: $1400 economy, $2600 priority. Just to be clear these are shipping costs only and exclude the goods themselves and customs charges. Shipping cost is the same regardless of whether you opt for plastic or metal ClearVue system. But DeAnn points out shipping costs very variable in the age of covid.
I have no metalwork skills but I have been thinking of (a) handing Bill Pentz plans to metalwork shop; (b) making Bill Pentz cyclone from plywood coated with glass and epoxy; (c) forget cyclone idea and install 2-3 bag bog standard extractor with 30 micron bags in outside shed.
(C) not seeming such a bad option as my understanding is that removing cyclone reduces power required to achieve CFM, I think 3hp instead of 5, which has other benefits
(C) not seeming such a bad option as my understanding is that removing cyclone reduces power required to achieve CFM, I think 3hp instead of 5, which has other benefits
I received similar shipping estimates a few years ago from Oneida when I asked about the Super Dust Deputy XL. The lowest cost just for shipping was about $1,000 for UPS because the item was too large to be mailed through the US Post Office. I bought the SDD XL from Toolovation in the UK and paid about £20 for shipping to Germany.
Option C will certainly work, but everything sucked up by the extractor will pass through the impeller blades before going to the bags. For small dust particles, this shouldn't be a problem, but large chunks of wood could damage the impeller blades or get wedged between a blade and the housing. The cyclone does reduce the efficiency a little, but it separates most of the dust and all of the larger pieces sparing the impeller and filter.
sploo
Somewhat extinguished member
Josh - consider also a Thien Baffle (J. Phil Thien's Cyclone Separator Lid w/ the Thien Cyclone Separator Baffle). They're significantly easier to build, and may be a solution to the problems with option C that Mike's pointed out.
Thanks, will do. Not sure if article covers it but will need to know extra horsepower required to drive it ..,
sploo
Somewhat extinguished member
That's a more difficult one, as that information seems to be lacking for the Thien Baffle (vs cyclones). Certainly it will drop the airflow, and I don't think they separate as well as a cyclone. However, they're easier to build, and if the separation is good enough to not eject visible dust then if you're venting outside you might not need the filter bags (which will give you back some of the lost airflow).
Togalosh
Established Member
At the risk of sounding like a Bill Pentz fanatic, he had one & says they work well but only at a "trash can" size.
"We could build a much bigger trashcan separator that would work, but for the 1000 CFM we need for good fine dust collection, we end up needing a 5'2" wide trashcan that sits ceiling high"
Hold on, I've got that wrong. BP wrote his website ages ago & it doesn't mention an actual Thien Baffle but a far simpler trashcan can separator which has just 2 elbows through a plastic lid of a small bucket.
"We could build a much bigger trashcan separator that would work, but for the 1000 CFM we need for good fine dust collection, we end up needing a 5'2" wide trashcan that sits ceiling high"
Hold on, I've got that wrong. BP wrote his website ages ago & it doesn't mention an actual Thien Baffle but a far simpler trashcan can separator which has just 2 elbows through a plastic lid of a small bucket.
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Ive been thinking about the above comments regarding metal and being sucked up off the floor etc. I guess when my system is powerful enough i will end up using it to clear sny floor mess.... so i thought about a branched downhill section of pipe and a box to collect heavier bits, but it would probably fill up quickly... a mesh guard inside would obviously block up with woodchip, but maybe a line of neodinium magnets around the mouth of the intake, or sweep it into a pile and use a big fishing magnet in the pile? ( ive got one )
Togalosh
Established Member
They use them on the tabling of waste disposal units in commercial kitchens to stop cutlery going in.
Cool, should work then
to be fair, i think I'll be careful with it, its just me working in there
