A bio-inspired hammer approach to reduce energy consumption and improve pulverization quality in Caragana korshinskii processing

To reduce the high resistance and energy consumption encountered during the crushing of Caragana korshinskii , three bio-inspired hammer structures were designed by mimicking the sharp-tooth morphology and sliding-angle mechanism of the mantis foreleg. Gas–solid coupled simulations based on DEM–CFD, together with theoretical analysis, were employed to investigate the airflow field, particle motion characteristics, and impact–shearing mechanisms within the crushing chamber. The high-speed rotation of the hammer generated complex airflow structures and pressure gradients, which induced circular particle motion and promoted repeated impact and shearing interactions. Compared with the conventional rectangular hammer, the concave and convex bio-inspired hammers significantly increased particle velocity, impact frequency, and residence time, thereby enhancing interparticle collisions and overall crushing efficiency. Experimental validation demonstrated that the concave hammer exhibited the best crushing performance. The optimal operating parameters were identified as a concave hammer structure, a rotational speed of 2799 r·min⁻¹, and a crushing segment length of 10 mm. Under these conditions, the average mass fractions of the crushed products were Y ₁=11.37%, Y ₂=48.62%, and Y ₃=40.01%, representing substantial improvements compared with the conventional rectangular hammer. This study elucidates the underlying mechanisms by which hammer geometry regulates particle dynamics and crushing efficiency, and provides a theoretical and practical basis for the structural optimization of Caragana korshinskii pulverization systems.