kiln air circulation

[bedway]

 I built a DH kiln and ran two loads thru it. The wood was air dried down to about 12 to 14%. Both loads came out of the kiln in under 8% and within 6 days. My problem is at the end of the steralization  cycle after the second load it toasted the fan inside. The temp. inside got up to 157degrees and blew the thermal fuse on the walmart (all metal) fan. After doing some surfing it appears finding a stand alone, high temp., inexpensive fan is near non existent. Im brain storming going with a squirrel cage with the motor mounted outside the kiln. Any thoughts, input would be appreciated.

[GeneWengert-WoodDoc]

Many kilns use a motor outside and a shaft running inside to the fans. Even more kilns use a motor designed to withstand the heat.

[Den Socling]

I've seen a lot of "kiln duty" motors fail. A company that I worked with many years ago claimed that class B lasted as long as the expensive motors. Ducting is a decent idea or, as Gene says, they have been mounting motors outside and using a long shaft for a long, long time.

[scsmith42]

I've been using Dayton TEFC motors on the fans in my kiln for years.  5 of the six still have the original motors and 4 of the six still have the original capacitors.

Graingers PN is 5UKE7.

We crank the heat to 150 - 160 at the end of every kiln cycle.  It helps to leave the motors running for 1 - 2 hours after turning the heat down at the end of the cycle. 

[WDH]

http://www.mechatronics.com/products/ac-axial-fans/UF25HC/

These are the type fans in the Nyle L53 dehumidification Unit. 

[woodman58]

I am going to be putting 4 of these fans mounted to a sheet of plywood across the center of my kiln. They are mady to be in hot areas. You  will have to remove the thermostat.