Question

In hammer mill operations, the dominant force is

• A. Compressive force
• B. Shear force
• C. Impact force
• D. Centrifugal force

Hint:

The name of the equipment gives a strong clue to its mechanism. A \textbf{hammer} mill works by hitting or \textbf{impacting} the material. A roller mill works by compression. A disk mill works by shear/attrition.

Answer 1

The Correct Option is C

Step 1: Understand the mechanism of a hammer mill. A hammer mill consists of a rotating shaft to which a series of hammers are mounted. As the shaft rotates at very high speed, the hammers swing out and strike the material fed into the mill.

Step 2: Identify the primary action. The material is shattered and broken down by these high-speed collisions with the hammers. This action is defined as impact. While other forces like shear and compression (attrition) may also play a minor role as particles are pushed against the screen, the dominant and primary force responsible for size reduction is impact.