Cyclone dust collector (again)

[rev]

I read on Bill Pentz’ site (airfoil blower page FAQ) that his 2hp, airfoil impeller, 6” duct, cyclone system produces “7160.34 feet per minute (FPM) airflow” and “a real 1407 cubic feet per minute (CFM)” (His motor runs at 3450 rpm.) This is way over the recommended requirement of 4000fpm and 800cfm.

I wonder then if a 2hp motor is really necessary with an airfoil impeller but if a 1hp motor might do the job adequately since doubling horse power only yields a small improvement in the volume of air moved? The reason for this question is that I want to run the system I am thinking of building on the same 10 amp circuit as other equipment and therefore want to keep the “current overhead” of the dust extractor to a minimum as it would be running in the background virtually the whole time. I think Wayne Davey also grappled with this issue but elected to use a readymade 2hp dust collector blower using the less efficient impeller type due to ready availability and cost. I wonder if the added cost of an airfoil impeller might be saved with the lower running cost and purchase cost of a 1hp motor.

Of course the next problem is where to source an airfoil type impeller in Oz? … or to consider importing from Bill’s source? Any ideas please?

Cheers,
rev

[gatiep]

With the least dust build up on the impeller, the airfoil impellers loose their efficiency very fast. So maybe Bill gets those figures on a clean system.....would be interesting to know what the readings will be with some build up. So I guess that the 1 hp unit will be pretty much near useless after a few days.

Airfoil 'impellors' are used in vapcoolers.

Cya

Joe

Have fun...................................keep turnin

[rev]

Thanks Joe,
Bill Pentz' says his system only creates about a couple of tablespoons of dust in the filter after 4 full waste containers - about 800 litres of waste I'd guess. Is this enough throughput of dust to cause problems for an airfoil system?

rev

[echnidna]

I wonder if placing the aitfoil impeller after the dust trap or cyclone would eliminate that problem.

[Wayne Davy]

Hi all,

If you read Bill's notes, his Air Foil Impeller IS mounted on top of the Cyclone therefore after the Cyclone separation of the bulk of the dust/chips. They have to be this way as even small Chips will destroy them. However, these things will collect the find dust on the blades (like the fans in our computers do) over a period of time. Without checking, I think Bill cleans his Impeller every couple of months or so to remove it.

The only problem I had with them is actually getting the Impeller in Oz for a reasonable (i.e. cheap) price. They are not a cheap item even in the USA and, after adding Freight and Insurance, it would cost a bundle delivery to Oz. Hence, I just went for the 2hp unit with a "Reverse Curved" Impeller from Hare & Forbes (insert Carbatec, Timbecon, etc. here).

While you can make an Air Foil Impeller like a few have done OS, from what I have read/heard/been told, it is a bit of an endevour to get perfect balance etc and they can be quite fragile.

Also, as for using a 1hp Motor to run one - FORGET IT. Just not enough guts to get a decent air flow running. 2hp is the sweet spot for these units and 3hp is actually the minimum for standard blade Impellers like mine (but 2hp will do - JUST).

Sorry to harp on (it's Friday night and the beers are going down nicely).

NEXT.... :D