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.
