This presentation covers principle, construction, working, advantages and disadvantages of perforated basket centrifuge.

1. PERFORATED BASKET
CENTRIFUGE

2. PERFORATED BASKET CENTRIFUGE
• Two types:-
✓Under driven
✓Over driven
• Under driven PBC:-
In this centrifuge a basket is mounted above a
driving shaft. Such arrangement is described as
under driven

3. PERFORATED BASKET CENTRIFUGE
• Over driven PBC:-
If the basket is suspended from a shaft .it is
described as over driven

4. PERFORATED BASKET CENTRIFUGE
UNDER DRIVEN PERFORATED BASKET
CENTRIFUGE
Principle:-
• It is a filtration centrifuge
• The basket contains a perforated side wall
• The separation based on the difference in
densities of solid and liquid phases

5. PERFORATED BASKET CENTRIFUGE
• During centrifugation, the liquid phase passes
through the perforated wall, while solid phase
is retained in the bowl
• The solid is removed by using a blade

6. PERFORATED BASKET CENTRIFUGE

7. PERFORATED BASKET CENTRIFUGE
Construction:-
• It consists of a basket, made of steel,(some times
covered with vulcanite or lead) or copper or
monel (it should be corrosion resistant material)
• The basket may have
0.90 metre diameter
0.085 metre cube capacity

8. PERFORATED BASKET CENTRIFUGE
• The diameter of the perforation should be
selected based on the size of crystal to be
separated
• If the size of the perforation is bigger than the
size of the particles to be separated. In such
cases filter cloth employed

9. PERFORATED BASKET CENTRIFUGE
• The basket is suspended on a vertical shaft
• Basket is driven by a motor using suitable
power systems such as belt pulleys, water
turbines and electric motors

10. PERFORATED BASKET CENTRIFUGE
• The basket may require
❖ 5 kilowatt power for starting
❖ 2 kilowatt power for running
A casing provided to collect the filtrate and
discharges it at the outlet

11. PERFORATED BASKET CENTRIFUGE
Working
• The material placed in the basket when the
basket is stationary
• The amount of materials placed should be
optimum otherwise the load will induce great
strain on the basket

12. PERFORATED BASKET CENTRIFUGE
• Power applied to rotate the basket
• The basket runs at 1000 RPM
• The power required for running is small
compared to the power required for starting
and bringing it to the full speed

13. PERFORATED BASKET CENTRIFUGE
• During centrifugation, the liquid passes
through the perforated wall, while solid phase
retains in the basket
• Liquid leaves the basket and is collected at the
outlet

14. PERFORATED BASKET CENTRIFUGE
• The cake is spun to dry as much as possible
• After a definite period of time the power is
turned off
• The basket is brought to rest
• The solid cake is cut using a blade and then
unloaded manually

15. PERFORATED BASKET CENTRIFUGE
Uses:-
Used for separating crystalline drugs from mother
liquor
e.g., aspirin
If mother liquor completely removed, free flowing
products obtained

16. PERFORATED BASKET CENTRIFUGE
Used to remove unwanted solids from a liquid
e.g., precipitated proteins are removed from
insulin
Sugar crystals are separated using perforated
basket centrifuge

17. PERFORATED BASKET CENTRIFUGE
Advantages:-
• Centrifuge is very compact and it occupies
very little floor space
• Slurries containing high proportion of solids
can be handled
• Materials having paste like consistency can
also separated

18. PERFORATED BASKET CENTRIFUGE
• The final products contain low moisture
content
• The process is rapid
• The cake containing dissolved solids can be
separated

19. PERFORATED BASKET CENTRIFUGE
Disadvantages :-
• The entire cycle is complicated resulting in
considerable labour costs
• Batch process
• Wear and tear of the equipment
• Solids may form hard cake, difficult to remove

20. THANK YOU