A hammermill is an invaluable tool when processing seed. It is used to break up the shell or pod containing the seeds or break apart seeds that are clustered together. We do this because we want to plant individual seeds and not a clump or cluster of the same seed.
The hammermill has ganged hammers (see picture above) that rotate around a chamber with a perforated screen placed inside; the results drop into a plastic container. There are varying sizes of screens and the hammers can be operated at varying speeds. We have 4 screen sizes: 1/8”, ¼”, ½” and ¾”. We chose this variety as it will suit the needs of any seed we collect.
Knowing what speed and what size screen to use comes with experience but not to worry, it’s nearly impossible to do anything wrong with this! If you want a very fine product use a high speed and a small hole size for the screen. The beauty of this piece of equipment is that you can change the screen and change the speed to fit the size of each seed.
This hammermill was purchased from CS Bell Co. They will custom make this cast iron and steel hammermill to your specifications; we chose Model 10 with a bottom discharge. It has a 1.5HP electric motor with variable speed drive control, which requires a 220 outlet. It has a 6” chute for the input of the seed and an 18” tall clearance for the output; this clearance height allows for the size of a plastic bin to be placed in this area to collect the seed and resulting chaff.
It is a very dusty, dirty, and loud operation. Be sure to locate the hammermill outside and wear a dust mask, eye protection, and ear muffs. The Nachusa Grasslands has an indoor unit with a dust mitigation system. The Prairie Enthusiasts had a field trip to this preserve in August 2013; I took this picture of their hammermill with dust collecting system.