Hammer mill (Size Reduction)

Link for the previous lecture: https://youtu.be/xN1wObeQN3s Hammer Mill In this lecture, we discussed principle, construction, working, merits, demerits and applications of hammer mill. Hammer mill is defined as the device which is used to crush the agglomerates or large sized particles into small size particles with free-flowing properties. Hammer mill works on the principle of impact. It consists of • Feed chute (hopper) • Grinding mechanism • The discharging chute. In hammer mill, the material is crushed or shattered by the repeated hammer impacts, collisions with the walls of the grinding chamber as well as particle-on-particles impacts. 1. Brittle materials are best fractured by impact from blunt hammers. 2. The machine is easy to install and operate and its operation is continuous. 3. It has high size reduction ratio and high capacity whether used for primary, secondary or tertiary grinding. 4. It is not recommended for the fine grinding of very hard and abrasive material due to chances of excessive wear. 5. It is not suitable for thermolabile, low-melting sticky and plastic-like material due to heat generation in the mill during the operation. It is used in pharmaceutical industries to process wet or dry granulations, powdering of Active Pharmaceutical Ingredient (API), excipients, barks, leaves, roots, crystals and filter cakes.