The document discusses various types of agitators used for mixing liquids in various applications, including their functions, advantages, and disadvantages. It contrasts agitation with mixing, explains the difference between laminar and turbulent flow, and outlines multiple specific types of agitators such as paddle, anchor, radial propeller, and helical agitators. Additionally, it covers the calculation for the number of agitators required in a system based on specific parameters.

2. Contents:
Introduction
Agitator?
What It can do?
Agitation Vs Mixing
Laminar Vs Turbulent Flow
 Agitators Types & Applications
 Agitators Types & Function
 No. Of Agitators Calculation

3. Introduction:
 What Agitator Do??
It can be used in various operations like reactions,
work up's, drying, filtration etc.
Agitator??
An agitator is something which is used to stir
liquid or mixture of liquids.

4. Introduction:
Agitation and Mixing:
Agitation Mixing
Agitation is the process of keeping a
mixture that has been mixed in the proper
mixed state required for the 'end' product.
Mixing refers to the actual stirring of
different liquids and/or materials to blend
them together into an end product or
mixture.
Forcing a fluid by mechanical means to
flow in a circulatory or other pattern in a
vessel.
Blending of 2 or more separated phases,
such as a fluid and a powdered solid, or 2
fluids, and causing them to be randomly
distributed through one another.
E.g. Agitator of reactor / vessel etc. E.g. Circulation of fluids in tank through
pump.

5. Introduction:
Agitation and Mixing:

6. Flow By Agitators

7. Agitator Types
•Two types of Agitators commonly used,
1.Mechanical Agitators,
2.Electronically Controlled Agitators,
Note: We will discussed commonly used Mechanical
Agitators.

8. Agitator Types:
•Paddle Agitators:
This is one of the most
primary types of agitators
with blades that reach up
to the tank walls.
Paddle agitators are used
where an uniform laminar
flow of liquids is desired.

9. Paddle Agitators Application:
Agitator
Type
Applications Advantages Disadvantages
Paddle
* Mixing of Solids,
* Slurry Mixing,
* Used during
Crystals
forming phase
during
Super saturated
Cooling
* Heavy duty,
* Apt for Slow
operation,
* Can have 2 or
4 blades
* Power
Consumption is
very high,
* Inefficient
Mixing

10. Agitator Types:
•Anchor Agitators:
This simple agitator
consists of a shaft and an
anchor type propeller.
 Mounted centrally or
at an angle.
Mainly used in
reactors.

11. Anchor Agitators Application:
Agitator Type Applications Advantages Disadvantages
Anchor
* Highly used
in Pharma
Industry for
Several
Operations
* Increase
possible
heat transfer
rate in reactors,
from reactor
heat transfer
surface to Mass.
* Required high
Efficiency
Gearbox,
* Required high
Power.

12. Agitator Types:
•Radial Propeller Agitators:
It consist of propellers that
are similar to marine
propellers.
They consist of two to four
blades that move in a screw
like motion, propelling the
material to be agitated
parallel to the shaft.

13. Agitator Types:
•Propeller Agitators:
It is shaped with blades
tapering towards the shaft
to minimize centrifugal
force.
It produces maximum
axial flow.
It is popular for simple
mixing jobs.

14. Propeller Agitator Application
Agitator
Type
Applications Advantages Disadvantages
Propeller
* Suitable for
GLR's, ANFD's,
can handle
Corrosive
materials with
Glass lining.
* Will increase
the homogeneity,
* Can be used in
two different
patterns for
drying and
pressing.
* Need to be
operated at high
speed to avoid solid
settlings in reactors.
* Need to be
operated at low
speeds in drying
operations.

15. Agitator Types:
•Turbine Agitators:
It can create a turbulent
movement of the fluids due to the
combination of centrifugal and
rotational motion.
Sub Classifieds:
Disc mounted Flat Blade Turbine
Hub Mounted Flat Blade Turbine
Hub Mounted Curved Blade
Turbine
Shrouded Turbine Impeller

16. Turbine Agitator Application:
Agitator Type Applications Advantages Disadvantages
Turbine
*Straight Blade
*Pitched Blade
*Curved Blade
*Disk Blade
* Liquids and
Gas reactions,
* Highly used
during Reaction
and Extraction
Operations.
* Generates
high Radial
Flow,
* Highly used
for dispersion
operations
* Not preferred
for solvents
with
high viscosity[
NMT 20 cP]

17. Agitator Types:
•Helical Agitators:
It has blades with a twisted
mechanism, just like the threads
of a screw.
The curves result in a vigorous
motion of the fluids to be
agitated.
Are most useful for mixing
viscous liquids.

18. Helical Agitator Application:
Agitator Type Applications Advantages Disadvantages
Helical Blade
*Ribbon Type
*Helical Screw
* Most Probably
used in Paint
industry.
* Can handle
Visco-elastic
liquids
efficiently
* Low
possibility for
Radial mixing
Screw type
* Have to use in
addition to other
agitators.
* Mostly used in
Food processing.
* Uniform
mixing of High
viscous
masses.
* Not preferred
for im-miscible
solvents.

19. Agitator Types & Function:
Marine Propeller:
It is produced by casting process in a foundry.
It has 3 or 4 blades.
Cast agitators have two basic advantages, uniformity of
material and hard surface.
These have tapering blades, and angle of blade varies
from root to tip.
This produces maximum axial flow.
The diameter of Marine Propeller impeller is 15% to 30%
of diameter of tank.
These have tip speeds between 300 to 500 meters per
minute.

20. Agitator Types & Function:
Axial Flow Turbine, Turbo Propeller and Flat Blade Turbine
 It has blades ranging from 3 to 6.
These have tip speeds between 200 to 300 meters per minute.
The diameter of impeller is 25% to 60% of tank diameter.
For Axial Flow Turbine and Turbo Propeller, the angle of blade
varies from 30 degrees (for less viscous liquids) to 60 degrees
(for more viscous liquids).
Standard angle is 45 degrees.
Power requirement increases with higher pitch angle.
For Flat Blade Turbine, the length of blade is 25% of diameter,
and disk diameter is 60% to 70% of the diameter of impeller.

21. Agitator Types & Function:
Paddle, Anchor, or Gate
It has only 2 blades.
These extend close to the tank wall.
It has tip speeds between 80 to 150 meters per
minute.
These push and rotate the liquid in a laminar flow.
 There is no axial or radial mixing.
The width of blade is 1/8th or 1/10th of the agitator
diameter.

22. Number of Agitators:
There can be many number of agitators
connected to a shaft, and it can be calculated
as below:
No. of Agitators = (Max. Liq. height x Sp.Gr.)
Diameter of tank.
Gap between two Agitators
= Liquid height
(No. of impellers - 0.5)

23. Agitator Types & Function:
Paddle, Anchor, or Gate
It has only 2 blades.
These extend close to the tank wall.
It has tip speeds between 80 to 150 meters per
minute.
These push and rotate the liquid in a laminar flow.
 There is no axial or radial mixing.
The width of blade is 1/8th or 1/10th of the agitator
diameter.