How to manually "file" files into folder, quickly, only using the keyboard
If your Mac is running Mavricks or later, you could try opening multiple tabs using CMD+T in a Finder window to rapidly copy/move files from the  "source" folder where your scanned files are located (in the first tab) to other "destination" folders visible in the other tabs. Press CTRL+TAB to move forward to the next tabbed window or CTRL+SHIFT+TAB to move backwards to the previous tabbed window. If you know which destination folders you'll be moving your files to then you can open a tab with each of those folders visible before you get started. 
Do your file preview &amp; rename in your first tab, then press CMD+C to copy the file. Press CTRL+TAB however many times you need to move to the destination tab then press CMD+OPT+V to move the file into that folder.