Rotar y drum screen
A rotary drum screen is a rotating filter. The incoming
stream passes through one side of the drum; the solid
particles stick to the screen and are deposited on the
other side of the tank. A scraper cleans the drum when it
passes the waste collection screw conveyor.
Advantages
• Depending on the size of the mesh, the smallest
particles can be removed from the water stream.
Disad vantages
• Since material can be washed over the drum, large
rolling angles of the platform pose a problem.
4.2.2.2 Size reduction
Reducing the maximum particle size of the material allows
for more efficient storage and transportation, and
reduces the chance that the debris clogs machines.
Shredder
In a shredder, material is torn apart by large rollers which
have cutters to tear up the material and pull it into the
machine until it is small enough to be discharged. Other
types of size reduction equipment are available, like
granulators and grinders, and all work in the same way as
the shredder. The difference between these machines is
the input size, output size and material flow. Which specific
machine should be used will be decided in the final
concept.
Advantages
• Storing the material is more efficient when it is
shredded, since less empty space is trapped between
the parts.
• If the material is shredded to a smaller maximum size,
this makes it easier to handle during transshipment.
Disad vantages
• Shredding material requires a large energy input,
which is not desired.