The AM Forum

A new and maybe cheap thing has been found. A used centrifugal or centripetal blower from a "bounce house"- one of those huge inflatable yard castles children enter and jump up and down in. A new ham friend found one where a family had thrown out the bounce house after the children had played with pikes or something and ripped holes in it.

The wheel is thin and large, maybe 1 Ft diameter, the casing being about 2.5" wide, it seems to run fast and it delivers a heck of a lot of volume at a high pressure and high velocity. I have not put the manometer to it but it is more pressure than most blowers. It's noisy operating openly so what else is new.

Might even be useful to distribute air to more than one piece of gear, or could be run slower and make air quietly for a large TX.

I'll post the manometer readings and pics later, perhaps this idea is useful considering the cost of blowers. In the meantime the picture and chart shows what I am speaking of.

Might be good for blowing tumbleweed ;D   You do have tumbleweed in Dallas.  We don't have any here in NJ.

I'll let you know if I think of any other uses for the blower.

Fred

It might also be good for drying out carpet or as a blower to remove kitchen odors or periodically ventilate a small building in summer heat. We do not have tumbleweed in Dallas. You have to go outside the city for stuff like that. The owner wanted too much in trade for it so that's the end of it.

Fyi 1000 pascals equals about  4 in. Water column or about 7.5 mm Hg.
Interesting blowers.  

Ideas from useful to the sublime.

Pressurize your ad sign or giant call letter ID.
Pressurize your balloon field day shelter.  Hey, today is field day, I almost forgot.
Pressurize your giant metallized spherical antenna.
Run your casting forge at steel melting temperatures.
Pressurize your own clean room where the family cat is not invited.
Run your roof siren for fun and profit.
And thousands of other uses, Boys and Girls!

I like the fact that it has a high back pressure capability.


Some important points:

Since it runs on 120 VAC,  will a Variac slow it down with less noise?  Does it heat up or stall out when run at very slow speeds?


How loud is the motor itself and how about the airflow... does it have whistle air noise generated by sharp edges inside?

If it makes too much noise, it could be mounted on an outside wall and ducted in. However, this puts it in the same old category as any big, noisy blower.

It would be nice to find a quiet, powerful, plastic blower for cheap that could be run real slow and mounted right on the rig.


T

http://www.youtube.com/watch?v=n9tC4ErgZvg

 ;)

The motor is pretty good size. usually I would say PSC type or centrifugal start, but there is no evidence of external cap or of centrifugal motor behavior. A huge shaded pole? it is about 1/4HP. It has cooling fins on it. I am not convinced it would run cool at lower speeds or be easily speed-controlled with any accuracy. The motor itself is not noisy. It is the intake and exhaust which are noisy.

It doesn't sound too loud considering it is running full strap.  It appears to work very well with back pressure seeing how stiff the bounce house became at the end.

The motor may not like continuous service as well as lowered voltage for slower speeds. So that wud be the main issues to check out.  I'll bet it wud be reasonably quiet running at 1/4 speed.  That shud be plenty of air for an 8877 or  4-1000A class tube.

T

I'm using two of these Cincinnati pressure blowers for my cavity amplifier at VHF (at work). I use a 10 inch impeller version for blowing over 300 CFM into a 6 inch hose that splits into four smaller hoses and feeds the sides of the output circuit (cavity) through RF screens. For the filament side of the tube, I use a 14 inch impeller to push 125 CFM with 10 inches water backpressure. It blows through the contact fingers of the socket and leaks out through the input circuit. Its quite a screamer when these two blowers ramp up, running on variable freq drives. Each motor is about 3 HP, 208 3 phase.

Its good to have more than enuf air.

http://www.cincinnatifan.com/centrifugal-pb.htm

Those are a bunch of beautiful blowers. I spent about an hour on that site.