2. Md Samrul Islam
Sabbir Ahmed
Mimma Sultana Chandni
Reeti Sushan Roy
Faria Iqbal
Mosharaf Hossain
3. Definition
Principle of Centrifugation
Classification of Centrifugation
CONSTRUCTION
ADVANTAGES AND DISADVANTAGES
Application in industry
Application in Water Treatment
References
4. Centrifugation is a process used to separate
or concentrate materials suspended in a
liquid medium. The theoretical basis of this
technique is the effect of gravity on particles
(including macromolecules) in suspension.
Two particles of different masses will settle in
a tube at different rates in response to
gravity.
5. A particle,whether it is precipitate,a macromolucle or
cell organelle when rotated at high speed is subjected
to a centrifugal force. Centrifugal force is defined as
F=mw2r
Where
F=intensity of centrifugal force
m= effective mass of sedimenting particle
w= angular velocity of rotation
r = distance of migrating particles from central
axis of rotation
CENTRIFUGATION:
7. Principles of Centrifuges
Basis of Separation :
Size
Shape
Density
Methodology:
Utilizes density difference between the particles and the medium in which
these are dispersed
Dispersed systems are subjected to artificially induced gravitational fields.
The centrifugal force causes the sedimentation of heavier solid particles.
8. Centrifugal Force :
Consider a body of mass m rotating in a circular
path of radius r at a velocity v. The force acting
on the body in a radial direction is given by:
F =
Here, F = centrifugal force
m = mass of the body
v = velocity of body
r = radius of circle of rotation
mv 2
r
The same body will be acted upon by a gravitational force. It can be
expressed as:
G = mg
where, G = gravitational force , and
g = gravitational constant
9. The centrifugal effect is the ratio of the two forces, so that:
C = F / G
= mv2 / mgr
= v2 / gr
But,
v = 2πrn
Where, n = speed of rotation.
So,
F / G = (2πrn)2 / gr
= 4π2r2n2 / gr
= 2 π2n2d / g ……………(1)
Where, d = diameter of rotation.
Continued…..
10. The gravitational constant has a value of 9.807 m/s2, so that equation (1) may be
simplified to:
Centrifugal effect = 2.013 n2d
Provided that , n is expressed in s-1 and d is in meter.
From the equation, it can be drawn that the centrifugal effect is proportional
directly to the diameter, but is proportional to the square of the speed of the
rotation. Thus, if it is necessary to increase the centrifugal effect, it is of greater
advantages to use a centrifuge of the same size at a higher speed, rather than use
a larger centrifuge at the same speed of rotation.
Continued…..
12. Centrifuges can be classified on the basis of :
• speed
• temperature
• use
On the basis of speed:
The "speed" of a centrifuge is measured in rotation per minute,
or rpm. Centrifuges are generally divided into 3 categories
based on their maximum attainable speed:
Low-speed : to maximum of 5 x 103 rpm.
High-speed : to maximum of 2 x 104 rpm.
Ultracentrifuges : to maximum of 105 rpm.
13.
14.
15.
16. On the basis of temperature :
Refrigerated centrifuges have a built-in refrigeration unit
surrounding the rotor, with a temperature sensor and thermostat
permitting selection of a particular temperature or a permissible
temperature range that is maintained during centrifugation. Many
biological samples are temperature sensitive, and centrifugation in
the cold (1-4oC) is frequently required.
Centrifuges that are not refrigerated are normally used at whatever
temperature the room they are in happens to be. This is typically
described in research reports as "room temperature" or “ambient
temperature”.
17. On the basis of use :
Centrifuges
Laboratory equipment
1. Swing-out arm type
2. Angle type
3. Ultracentrifuge
Commercial equipment
Perforated bowl types Sedimentation centrifuges
Batch
1. Top driven
2. Under driven
Semi continuous Continuous or
Super centrifuge
Vertical
1. Simple bowl
2. Bowl with plates
Horizontal
continuous
decanters
19. It allow separation of many or all
components in a mixture and allows for
measurement to be made
There are two forms of Density gradient
centrifugation :
Rate zonal centrifugation
Isopycnic or sedimentation
equilibrium centrifugation
20. In Rate zonal centrifugation the solution have
a density gradient. The sample has a density
i.e. greater than all the layers in the solution.
The sample is applied in a thin zone at the
top of the centrifuge tube on a density
gradient. Under centrifugal force, the
particles will begin sedimenting through the
gradient
21. The particles will begin sedimenting in
separate zones according to their size shape
and density.
22. In this type of centrifugation
,the solution contains a greater
range of densities.
The density gradient contains
the whole range of densities of
the particles in the sample.
Each particle will sediment
only to the position in the
centrifuge tube at which the
gradient density is equal to its
own density.
In Isopycnic centrifugation
separation of particles occurs
into zones on the basis of their
density differences,
independent of time.
23. Differential centrifugation is a common
procedure in microbiology and cytology used
to separate certain organelles from
whole cells for further analysis of specific
parts of cells.
In the process, a tissue sample is
first homogenized to break the cell
membranes and mix up the cell contents.
The homogenate is then subjected to
repeated centrifugations, each time removing
the pellet and increasing the centrifugal
force.
24.
25. The ultracentrifuge is a centrifuge optimized
for spinning a rotor at very high speeds, capable
of generating acceleration as high
as 2000000 g (approx. 19600 km/s²). There
are two kinds of ultracentrifuges, the
preparative and the analytical ultracentrifuge.
Both classes of instruments find important uses
in molecular biology , biochemistry, and
polymer science.
26. There are different types of laboratory
centrifuges:
Micro Centrifuges:
Devices for small tubes from 0.2 ml to 2.0 ml
(micro tubes), up to 96 well-plates, compact
design, small footprint; up to 30,000 g
Clinical Centrifuges:
Moderate-speed devices used for clinical
applications like blood collection tubes
Multipurpose High-Speed Centrifuges:
Devices for a broad range of tube sizes, high
variability, big footprint
27. Definition:
An industrial centrifuge is a machine used for fluid/particle separation.
Types:
Industrial centrifuges can be classified into two main types:
1.sedimentation centrifuge and
2. filtering centrifuges.
28. Sedimentation centrifuge:
Sedimentation centrifuges use centrifugal force to separate solids from liquids
as well as two liquids with different specific gravities.
Sedimentation centrifuges include decanter, disk-stack, solid-bowl basket and
tubular bowl centrifuges.
Filtering Centrifuges:
Filtering centrifuges use centrifugal force to pass a liquid through a filtration
media, such as a screen or cloth while solids are captured by the filtering
media.
Filtering centrifuges primarily deal with perforate basket, pusher and peeler
centrifuges.
29. The main parts of the Centrifuge are Bearing and Shaft,
Basket, Drive and Brake
BEARING AND SHAFT:
The Heavy duty bearing is chosen to withstand vibratory load
and centrifugal force and the shaft is made up of suitable
material and duly balanced independently without the basket
for higher accuracy.
BASKET:
The basket is made up of adequate thickness so as to
withstand the loads caused by the centrifugal forces .
DRIVE:
The drive consists of Motor mounted at the basket casing
driven through V belt with provision of the tensioning the
belts.
BRAKE:
The Centrifuge are fitted with external shoe brakes with brake
liners.
30. Centrifuges can be used in variety of
applications within the manufacturing
and chemical industry.
Workshop liquids can be cleaned and
be efficiently re-used by using
Separator centrifuges, Examples:
honing oil, quench oil, compressor oil,
lube oil, hydraulic oil, wash liquids and
coolants.
astewater contamination can be
reduced by removal of solids (decanter)
or by removing oily residues
(Separator).
Sludge dewatering in a pulp and paper
mill can be done more efficiently with a
decanter centrifuge.
31.
32. Advantages:
• Centrifuges have a clean appearance and have little to no odour problems.
• Not only is the device easy to install and fast at starting up and shutting down, but
also only requires a small area for operation.
They can be selected for different applications.
The machine can operate with a higher capacity than smaller machines.
The device is simple to operate .
Centrifuge has more process flexibility and higher levels of performance.
• Disadvantages:
The machine can be very noisy and can cause vibration.
The device has a high-energy consumption due to high G-forces.
The decanter centrifuge has high equipment capital costs.
33.
34. Production of bulk drugs:
aspirin is separated from its mother liquor by centrifugation.
Production of biological products:
a) Separation of blood cells.
b) Purification of insulin by selectively precipitating other
fraction of proteins.
c) Separation of most of the proteinaceous drugs and
macromolecules.
Biopharmaceutical analysis of drugs:
Centrifugation is used for separating the drugs which is essential for
the evaluation of pharmacokinetic parameters and bioequivalence
studies.
Application of Centrifuges
35. Evaluation of suspension and emulsion:
Centrifugation method is used as a rapid empirical test
parameter for the evaluation of suspension and emulsion.
Ultracentrifugation are used for determination of molecular
weight of serum albumin, insulin etc.
Isolation of bacterial cells, fungal and actinomycete
mycelium and fermentation media is facilitated by
laboratory centrifuge.
Removal of finely suspended solid matter (clarification) from
aqueous or oily materials.
Ultracentrifuge can be used for separation of virus particles
which has potential industrial applications.
36. IDENTIFICATION
2 mg halcinonide cream in a 50 mL centrifuge tube
15 ml water added and shaked to disperse
20 mL of chloroform added and shake for 5 minutes
Cooling & Centrifugation
Transfer the chloroform layer in a conical flask
Repeat the process
ASSAY: Chromtography is used .
37. IDENTIFICATION
centrifuge a portion of it and separate the solid by several
portion of water
re crystalized from hot alcohol and crystals are used for
identification
ASSAY
Measured volume of oral suspension equivalent to 1 gram
sulfixazole
Mixed with 40 mL of HCl and 25 mL glacial acetic acid
swirl to dissolve and add 100 mL water
Nitrite titration
0.1 M sodium nitrite equivalent to 26.73mg sulfisoxazole
References: 1.USP &
2. Centrifugation in biology and medical sciences by Philip Sheeler
38. Centrifugation
Separation of
solid substances
from highly
concentrated
suspensions
Separation of
Heavy particles
and large sized
grains by
cycloning
Separation of
Oily
concentrated
sludge
Separation of
oily
suspensions
with low SS
contents
39. Separating chalk powder from water
Removing fat from milk to produce skimmed
milk
Separating textiles
Removing water from lettuce after washing it
in a salad spinner
Separating particles from an air-flow
using cyclonic separation
40. The clarification and stabilization of wine
Separation of water particles from clothes
while spin-drying in washing machines
Separation of urine components and blood
components in forensic and research
laboratory
