Cooling Parts

Q. We have a powder coating line that runs up to 10-gauge steel parts. We use an elevated oven, and the parts come out of the oven and run for about 10 minutes before they reach the un-racking position. The heavy gauge parts are still too hot to handle. We use gloves, but operators still complain about the hot parts and the air temperature in the unload area. What can we do to cool these parts faster? R.C.

A. Hot parts can be cooled by time or air movement. You can increase the amount of rail if you have room, or you can add air movement to the current route. Adding fans along the route will help, but it does stir up a lot of dirt and air movement across the area. If you use a tunnel, it helps.

The best arrangement is to add a push/pull fan arrangement and take outside air into the end of the tunnel and exhaust a similar volume of air at the entrance end. A large volume of air used this way will drive the temperature down much faster than ambient air. The inlet fan needs to be adjustable to take some indoor air if you are in a cold climate. The amount of air will vary based on the part mass and volume. It is typically quite high (10,000 – 30,000 CFM (cu ft/ min). In some extreme conditions, a line may need refrigerated cooling. But in most cases, an addition of time or air will get those parts down to a reasonable handling temperature.