Wood chip sizes and grain cleaner (Wood Chip gasifiers, Only)

We (George Adams and Pete Stanaitis) just got this grain cleaner:
http://www.tractorhouse.com/listingsdetail/detail.aspx?OHID=6977227

Well, not THAT one, but one just like it.

The machine works very well for sorting/cleaning wood chips, The front screen (closest to the input funnel) has 1/4" squares hardware cloth and the rear section (Now) has 1/2" square hardware cloth in it.
The first stage is a cone of hardware cloth inside the front screen. This cone has 3/4" squares hardware cloth. The job of this section is to sort away the largest, coarsest material. It does a great job of doing that. This large material falls out the center of the machine. The “fines” fall out anywhere from the front to about 6" from the tail end.
The good stuff falls out the very end of the drum.
So— the range of chips that we get out the far end of the machine is between 1/2" square+ and 3/4" square-.
We can change the hardware cloth in any of the 3 sections without too much trouble.

Our questions:

  1. Do any of you use a grain cleaner like this, and if so, what size chips do you shoot for and what size screens do you use?
  2. Regardless of how you get your chips ready, what size range do you use.

Did some testing with the grain cleaner today. There were some good results and some problems to overcome. Hopefully with the next run we can make a video. The inner screen was 3/4" by 3/4" which made the maximum size chip 3/4" inch. Anything larger than that went out with the trash so for now the inner screen was removed. The 1/4" and 1/2" screens on the out drum are doing a good job of removing the fines. The sticks in with the chips are coming through with the good chips but a limited number of those should be OK with my gasifier. It would be nice to find a way to get more of them out of the chips.
We have been getting a lot of rain here so the chips were wet. They don’t go through as well as dry chips. Without the inner mesh in place the transit time for a 5 gallon pail of chips was 10 to 20 seconds. That was from the time it was dumped until all the chips had cleared the drum. It cleaned the chips as fast as I could fill and dump 5 gallon buckets into the hopper.