[TheForge] Re: forge blower, dimmers, etc.

[Mike Spencer]

Marc Godbout <marc at ironringforge.com> wrote:

> Isn't a squirrel-cage blower the same as a centrifugal?
>
> On Mon, Nov 30, 2009 at 9:22 AM, Bruce Freeman <freemab222 at gmail.com> wrote:
>> A squirrel-cage blower might not provide enough pressure for a coal
>> forge.  A centrifugal blower is better.

A squirrel cage blower is a centrifugal blower.  Shame on Bruce. :-)
But it's designed to move large volumes of air.  The cage doesn't
nearly fill the chamber in which it's rotating.  The typical forge
blower has paddles that more closely fill the chamber and build up
a bit more pressure.

I happen to be thinking about this because I've just managed to
disassemble a oil furnace gun burner that's been out in the rain for a
decade.  After removing the rust and ant's nest, the motor works fine.
But the squirrel cage impeller disintegrated.  I'm trying to fab up a
paddle impeller on the hub of the dead one.  Lots of fiddly little
bits filed, shimmed, tweaked and welded together.  No speed control on
a 1725 RPM AC motor but I don't have to build the widget with two
throttle valves for air diversion because I have a mil surplus gadget
made to do the very thing.  All I have to do is free up the rusted
gate/flap/door in the thing and plumb it onto the blower.

That's all assuming that the impeller I'm making doesn't fly apart and
isn't so out of balance that it shakes everything to pieces.


- Mike

-- 
Michael Spencer                  Nova Scotia, Canada       .~. 
                                                           /V\ 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^