Here are some images of approaches we use on our farm - everything from the screw in "pencil" dryer fans to drying outside or hoop structure on tarp up to 10 tons. If you have the weather and the quantity isn't that large - it is a very fast and economic way to get grain dry, and is not much labor. We have also used a small bin with a screen bottom and fan (Image is of Cayuga pure organic's dryer). I agree that it would be good to post sources for the bottom screen and fans. I have also heard of using drainage tile inside grain wagons or bins (prior to dumping grain in) used with the pencil type dryers or other fans. I have not had to try that yet, but expect I will at some point.
Some small scale grain drying options
for an even smaller scale