WHAT ARE THE DIFFERENT TYPES OF HAMMER MILLS AND HOW DO THEY WORK?

 Hammer mills are versatile machines widely used in various industries for size reduction and grinding operations. They are commonly employed in the agricultural, forestry, and manufacturing sectors. The hammer mill works on the principle of impact, where a rotating hammer assembly strikes the material to be processed, reducing its size into smaller particles. In this article, we will discuss different types of hammer mills and delve into how they function.

Different types of hammer mill and also their functions

1.       Gravity discharge hammer mill

The gravity-displacement hammer mill is the simplest and most common type. It operates with a basic design where the material is fed into the grinding chamber. Moreover, it is repeatedly struck by rotating hammers until it reaches the desired size. The particles then exit through a screen located at the bottom of the mill.

2.       Pneumatic discharge hammer mill

Unlike the gravity discharge hammer mill, the pneumatic discharge hammer mill uses an air system to evacuate the ground material. It operates similarly to the gravity discharge mill but with the addition of an air-assist mechanism that assists in the removal of particles through the screen. This type of mill is particularly used for grinding light, fibrous materials.

3.       Dual-stage hammer mill

The dual-stage hammer mill consists of two separate grinding chambers stacked one above the other. The first-stage chamber contains larger hammers that impact and coarsely grind the material. The partially ground material then passes through a perforated screen into the second stage chamber, where it undergoes further grinding using smaller hammers. This design allows for more efficient grinding and finer particle size control.

4.       Full circle screen hammer mill

The full-circle screen hammer mill has a circular grinding chamber with a screen that wraps around the entire circumference. This design allows for higher throughput because the material is repeatedly hammered by the hammers and passed past the screen. It is frequently used to grind grains, biomass, and other materials that require a finer end product.

5.       Horizontal in-feed hammer mill

In a horizontal in-feed hammer mill, the material enters the grinding chamber horizontally and distributes across the full width of the rotor. This type of mill is used for grinding bulky and oversized materials such as wood chips, bark, and agricultural residues. The horizontal feed design ensures efficient processing and minimizes the risk of blockages.

6.       Vertical scrap metal hammer mill

Vertical scrap metal hammer mills are designed for processing and recycling metal scraps. They feature a vertical rotor shaft with hammers attached, which efficiently breaks down metal pieces into smaller fragments. The shredded metal can then be separated and recycled for various applications.

7.       Hammer mill with cyclone

A hammer mill with a cyclone is a specialized variation that incorporates a cyclone separator in the grinding process. The cyclone assists in separating the ground material from the air and collects fine particles, allowing for improved dust control and material recovery. This configuration is used in applications where fine grinding and precise particle separation are crucial.

Conclusion

Hammer mills are versatile machines that offer efficient and effective size reduction and grinding solutions across a wide range of industries. Ecostan provides simple gravity discharge mills to the more specialized designs with cyclone separators. The choice of hammer mill depends on the specific requirements of the material and the desired end product. Understanding the various types of hammer mills and their operating principles can help industries make informed decisions when selecting the appropriate equipment for their processing needs.