Abstract: An assembly for cleaning material from a flowable product includes multiple stages of air cleaning for a product. Each air cleaning stage includes a vertical air column, an air knife, and at least one airlock. After introducing a product into the air column, the air knife disturbs material from the product and the material is carried away by the vertical air column. The airlock prevents significant disturbance of the vertical air column during operation. The cleaned product is delivered after a single cycle through the assembly having passed through several stages of cleaning.

Abstract: A grade sorting system and method. The grade sorting system is designed to sort items of various size grades into bins or other containers having items of similar size grades.