The top sieve in the cleaning shoe of a combine harvester. As the threshed crop falls onto it, a blast of air blows lighter dust and chaff out the back, while the heavier grain falls through its adjustable louvers onto the lower cleaning sieve for final sorting.
Heard on the job
Open the chaffer a fraction, we're blowing too much good wheat out the back.
Do not mix it up with
- Cleaning sieve: The chaffer is the upper sieve that catches large debris, while the cleaning sieve is the lower one that does the final sorting.
Related terms
Cleaning shoe
The assembly inside a combine harvester that separates the clean grain from chaff and small debris.
Combine harvester
A large self-propelled machine that reaps, threshes, and cleans grain crops in one pass.
Cleaning sieve
The bottom screen in a combine harvester's cleaning shoe that performs the final separation of grain.