Here at Acorn, we love seeds, and what we really love is clean seeds. Nice, healthy, ready to germinate seeds that don’t have any bad seeds or bits of chaff in them. We clean seeds in lots of different ways. We clean wet seeds with lots of buckets and water (look for photos this summer). With dry seeds we use tools as simple as a fan or a hand screen but also some very complex and interesting machines that make the job much easier for us.
There are two very common operations you do when cleaning seed. One is winnowing, this is where you use a fan or wind to blow stuff out of your seed that is lighter than it, usually chaff. Another common task is screening, this is where you are cleaning out seed that is too small and non-seed objects that are too small or big. This usually involves using screens. What you see here is an air seed cleaner which combines those two tasks into one machine.
This is a small air-seed cleaner we also have a much larger (5 by 6 foot) one.
Sometimes when you are cleaning seed, you have seed that you know is bad but is the same size as the other seed you are cleaning. You can’t screen it because it is the same size but often, bad seed is less dense than good seed. That’s when you use a gravity table. A gravity table is a vibrating inclined plan with air blowing out the surface of the plane. Dense stuff goes up the slope and into one chute, lighter stuff goes down slope and out the other. Once you tune it for the seeds you want you can really do some excellent seperation and make big improvements on a batch’s germination rate.
I hope this exceptionally seed-geeky post was enriching for everyone! I promise lots of delightful photos of flowers and growing things for the next post.