Hammer Mill , Construction , Principle , Working

Principle :

Impact Between rapidly moving hammers mounted on  a rotor  .

Construction :

1. Contains horizontal or vertical shaft or drum .

2. Hammer are made up of steel , stainless steel .

3. Bar Shaped hammer are used .

4. Hammer blades can be with flat or sharp edge .

5. hammer may be either rigid or swing type .

6. screens are prepared using  metal sheet of varying thickness with perforation .

Working :

1. Hammers are allowed to be in continuous motion 8000 - 15000 rpm .

2. Screens are interchangeable depending upon the fineness .

3. Fineness of the pdt can be regulated by rotor speed , feed rate , distance between hammers and grinding plate , number of hammers  , types of hammers and number and size of holes in screen .

 Advantages  :

1. Easy Setup and Cleanup .

2. Versatile .

Disadvantages :

1. Screen may get clogged  .

2. heat build up during milling .

3. Cannot be employed to mill with sticky , fibrous and hard material .

4. Wearing of mill and screen .