Abstract: Hammer mill is widely used in the feed processing industry. During its operation, the material is thrown against the inner wall of the sieve after being broken by the hammer. Limited by the annular structure sieve, the grinded material tends to produce a “air- material circulation layer” on the inner wall of the sieve, leading to problems such as low grinding efficiency and high grinding energy consumption. Considering the disruptive characteristics of the special profile structure of a pigeon’s wing on the airflow field, we extract the geometric characteristics of the coupling element and optimize the related structural parameters. Based on the principles of bionics, a new wing sieve is then designed, and its efficient grinding mechanism is studied. Compared to the commercial sieve, the experimental results indicate the bio-inspired sieve can significantly improve the material productivity and grinding quality.

Key words: Bionic design , · Hammer mill , · Sieve , · Pigeon wing