centrifugation ,Perforated-basket centrifuges(centrifugal filters), Tubular-bowl centrifuge

2. Centrifugation is a process that involves the use of the centrifugal
force for the separation of mixtures

3. Principle of centrifugationPrinciple of centrifugation

5. If a particle (mass = m kg) spins in a centrifuge
(radius r, m) at a velocity (v, m s-1
) then the centrifugal
force (F, N) acting on the particle equals m v2
/r.
The same particle experiences gravitational force
(G, Newton) = m g (where g = acceleration due to gravity)
F = m v2
/r
F= centrifugal force
Centrifugal force (F)Centrifugal force (F)

6. Centrifugal effect (C)Centrifugal effect (C)
The centrifugal effect (C) is the ratio of these
two forces, so C = F/G, i.e. C indicates how much
greater F is than G
Centrifugal effect, C=
Force acting in radial direction
Gravitational force

7. Consider a body of mass ‘m” kg rotating in a circular path
of radius “r” at a velocity of “v”
Centrifugal force =f= mv2
/r
Same body is experiencing gravitational force, it can be expressed
as “G= mg , where g = acceleration due to gravity, and m= mass
Centrifugal effect (C) = F/G
= mv2
/mgr
(v = 2 π r n )
c = (2π r n)2
/ g r
= 4 π2
rn2
/ g
(d= r/2)
= 2 π2
d n2
/ g
(g = 9.807)
C = 2.013 d n2

8. Centrifugal effect, C= 2.013 n2
dCentrifugal effect, C= 2.013 n2
d

9. Classification of centrifugesClassification of centrifuges
There are two main types of centrifuge used to
achieve separation on an industrial scale,
(1)Filtration centrifuge: Those using perforated
baskets, which perform a filtration-type operation
(work like a spin-dryer) and
(2) Sedimentation centrifuge : Those with a solid
walled vessel, where particles sediment towards
the wall under the influence of the centrifugal force
There are two main types of centrifuge used to
achieve separation on an industrial scale,
(1)Filtration centrifuge: Those using perforated
baskets, which perform a filtration-type operation
(work like a spin-dryer) and
(2) Sedimentation centrifuge : Those with a solid
walled vessel, where particles sediment towards
the wall under the influence of the centrifugal force

10. Perforated-basket centrifuges
(centrifugal filters)
Perforated-basket centrifuges
(centrifugal filters)

11. Fig. Perforated basket centrifuge

13. Tubular-bowl centrifuges
(centrifugal sedimenters)
Tubular-bowl centrifuges
(centrifugal sedimenters)

14. Fig: Tubular-bowl centrifuge

16. Continuous centrifugeContinuous centrifuge