Per decanter
centrifuge’s working principal, by high-G force of centrifugal force generated
by the high speed rotating centrifuge bowl, the solids particles are threw to
the outer layer inside the rotating bowl, the pushed by the impeller to the solids
discharge ports. Meanwhile, the liquid phase flows to the other direction and
discharged from the liquid discharge ports.
In this case, the
impeller’s material seems vital to the service life of the centrifuge, and the
protection of impeller is very necessary and different protection methods bring
different results.
Normally there
are several ways for impeller protection：
1. Spray welding:
it is a traditional and easy way to do the impeller protection and of a very
low cost. It provides around 1 mm height of protection, and the dynamic
balancing of impeller is done after doing the spray welding.
The advantage of
spray welding is low cost, disadvantage is that the welding layer is easy to be
worn out, and after the welding layer is worn out, the operator need to
re-balance the impeller after re-weld the protection. But in practice, most of
jobsites don’t have balancing machines.
Right now, most
of China solids control companies are still using spray welding for their
impeller protection.
2. ceramic tiles
for impeller protection: ceramic tiles are ideal protection for solids control
centrifuges, because they are of high anti-worn character. Comparing with spray
welding, ceramic tiles are equal in shape and size, when some pieces are worn
out an need to be changed, the operator just change the one and the opposite
one, no need to redo the dynamic balancing.
Advantage: no
need to redo the dynamic balancing when changing tiles, long service time because
of equal height of 4 mm, and high standard of anti-worn. Disadvantage: fragile
when installing onto the impeller, need more working hour for manufacturer for
installing.
GN Solids Control
use this kind of impeller protection on their economic configuration
centrifuges, which are normally used as solids control centrifuge.
3. tungsten
carbide tiles for impeller protection. It is now the internationally highest
standard impeller solution. The tungsten carbide tiles are of high hardness and
anti-corrosion characters. And they are of equally 4mm height.
Advantage: same
as ceramic tiles, no need to redo balancing after changing pieces, and more
anti-corrosive and anti-worn than ceramic, more suitable for waste management
centrifuges. Disadvantage: more expensive than the above 2 solutions.
GN Solids Control
use tungsten carbide tiles for GN high standard configuration of centrifuges,
first and best among China suppliers and of the highest international standard.