Agricultural Process Engineering

In an air screen grain cleaner with two sieves (top scalping sieve and bottom grading sieve):

Options:

• (A) Top sieve retains large impurities while passing good grain; bottom sieve retains good grain while passing small weed seeds and dust
• (B) Top sieve retains fine dust
• (C) Bottom sieve retains large sticks
• (D) Both sieves have identical hole size