This is presentation of Pharmaceutical engineering.

2. SUBMITTED TO-
DR. SANJAY KUMAR JAIN
SIR
DR. ASHISH JAIN SIR
SUBMITTED BY-
ARYA OJHA
B.PHARM 3RD SEMESTER
DEPARTMENT OF
PHARMACEUTICAL
SCIENCES
ROLL NO- Y19150014
SESSION- 2020:2021
DR. HARISINGH GOUR
VISHWAVIDHYALYA
SAGAR, M.P. 470003

3. ACKNOWLEGEMENT
•I would like to thanks Pharmaceutical
engineering teachers Dr.S.K JAIN SIR,
DR. ASHISH JAIN SIR who gave me
this opportunity to do this assignment.
•I pay my heartiest gratitude to my guide
and other faculties who helped and
supported me throughout my work.

4. HAMMER MILL
BALL MILL

5. 1.
• Size reduction
2.
• Mechanical forces used
3.
• Hammer mill
4.
• Principle, construction, uses, advantage, disadvantage
5.
• Ball mill
6.
• Principle, construction, uses, advantage, disadvantage

6. † Size reduction is a process of
reducing large solid unit
masses (chemical substances
or vegetables) into small unit
masses, coarse particles or fine
particles.
† Size reduction process is also
termed as Comminution,
Diminution or Pulverization.

7. Precipitation Method : Substance +
Solvent. Then it is precipitated by addition of
another solvent , which is miscible with the
first , but in the second solvent it is insoluble.
Mechanical Method : In this, substance
is subjected to mechanical forces using
grinding equipments like (ball mill, roller mill,
colloid mill, hammer mill etc.)

9. CUTTING
The material is
cut by means
of a sharp
blade.
Eg: Cutter Mill
COMPRESSION
The material is
crushed
between rollers
by application of
pressure.
Eg: Roller Mill

10. IMPACT
Material is hit by
rotating hammer
or stationary
surface and hence
splits apart.
Eg: Hammer Mill
ATTRITION
The material is
rubbed between
two surfaces.
Eg: Fluid Energy
Mill

14. A hammer mill is essentially a steel drum
containing a vertical or horizontal rotating
shaft or drum on which hammers are mounted.

15. † The hammer mill operates
on the principle of impact
between rapidly moving
hammers mounted on a
rotor and the powder
material.

19. † The hammer mill can be either the
horizontal or vertical shaft type.
†Hammers are usually made of
hardened steels, stainless steel, with
impact surface made of extremely
abrasive resistant material such as
haystellite and carbaloy.
† Stainless steel hammers are
sufficient for pharmaceutical
purposes.

20. † The two basic shape of hammers are:
STIRRUP BAR
†The unit is closed with a chamber
containing a grid or removable screen
through which material passes.
†Screens are prepared using metal sheets
of varying thickness with perforated holes.
†The hammer swings on the ends or fixed
to centre rotor.
†The material is put inside through rotor.

21. Firstly bulky drug material is stored
in hopper.
Through hopper it will start falling
down.
As you start the machine, the hammer will
start to hit the drug particles .
By the impact force , the particle’s size will
start to reduce.
The reduced drug particle will be passed
through the screen and will fall in receiver.

24. † The hammer mill are
mainly operated at 8000 to
15000 rpm in continuous
motion for reduction of
particles.
†The screen in hammer mill
are interchangeable so that
any grade of fineness can
be achieved.

25. † The hammer act as a
centrifugal fan so that
large amount of air is
drawn through the mill
to counteract the heat
generated during
milling.

26. Rotor
speed
Feed
rate
Clearance
between
hammer
and
grinding
places
Number
and
types of
hammer
Size of
discharge
opening
(screen)

27. † Fine to moderate grinding of
powders may be obtained.
†Non abrasive to moderately
abrasive materials can be used.
†Used to mill :
• Dry materials
• Wet filter press cakes
• Ointments
• Slurries

28. Easy to setup, dismantle and clean-up.
Various type of feed stock can be used, using different screen sizes.
Occupies small space.
It is versatile i.e. speed and screen can be changed rapidly.
Operated in closed environment so dust can be reduced and
explosives hazards can be prevented.

29. The screens may get clogged.
Heat buildup is more, so material degradation possible.
Very noisy.
Cannot be used for sticky, fibrous materials.

30. A ball mill is a type of grinder used to grind or
blend materials for use in mineral dressing
processes, paints, pyrotechnics, ceramics.

31. The ball mill operates on the
principle of impact and attrition .
Impact is between rapidly moving balls
and the powder material. mounted on a
rotor and the powder material.
The balls roll over each other and show
rubbing action, hence attrition force is
also responsible for size reduction.

34. † The ball mill consists of
hollow cylinder , mounted on a
metallic frame so that it can be
rotated on its horizontal axis.
†The cylinder is made of metal
and usually lined with chrome
(type of steel), rubber or
porcelain (in pharmaceutical
industry).

35. † The cylinder contains grinding
materials or medium called balls.
†They occupy 30-50% of mil volume.
†The ball size depends on
Size of feed
Diameter of mill
† Balls are made of steel, iron,
stoneware.

39. The drug is put in such quantity that it is
filled about 60% of volume in cylinder.
A fixed number of balls are
introduced and it is closed.
The mill is allowed to rotate on its
longitudinal axis.
The speed of rotation is very important.
The drug get their size reduced due to
impact and attrition.

40. Balls roll over each other causing attrition
between themselves.
As the cylinder rotates with correct speed the balls
are lifted up and cascade down due to centrifugal
force acting .
The drug is carried to top, where they break
contact with wall and fall at the bottom.
So impact force acts like this.
After size reduction the final drug material is
received.

41. The mill is allowed to rotate on its
longitudinal axis.

43. The correct speed of ball mill where impact and
attrition acts.

44. ROLE OF SPEED IN
BALL MILL.
At low speed of rotation ,
the balls roll over each other
and attrition will be a
predominant mode of action.
It can be used for wet
grinding.

45. At high speeds, the balls
are thrown out to the wall
by centrifugal force. This is
known as centrifuging.
Hence grinding would not
occur because the
compression by balls
against wall is not sufficient
to reduce size.

46. At correct speed
impact + attrition
causes the size
reduction.
Ball mills
successfully runs at
speed between 60 and
90 percent of critical
speed.

47. † The operating speed i.e. the correct
speed of ball mill must be less than
critical speed.
†The minimum speed at which
centrifuging occurs is known as critical
speed.
•Nc is the critical speed, in revolutions
per minute,
•D is the mill effective inside diameter,
in feet.
Critical Speed is: Nc =76.6(D0.5)

48. Properties
of feed
material
Feed
rate
Level of
material
in the mill
Weight
of balls
Speed
of
rotation

49. † Fine grinding with particle size 100 to 5 mm.
†Hard and abrasive materials can be used.
†Stainless steels balls are preferred in
production of ophthalmic and parenteral
products
†At low speed used for milling:
• Dyes
• Pigments
• Insecticides

50. Produces very fine powder.
Suitable for wet and drying grinding process.
Mill is closed system, so sterility is achieved.
Balls can be of various shapes and size. Rods can be used instead.
Installation, Operation and labor costs are low.

51. Noisy machine.
Wear occurs from balls as well as from the casing.
Slow process.
Cannot be used for soft, fibrous, tacky materials.

52. REFERENCES:
• SUBRAHMANYAM C.V.S, SETTY J,
SURESH S, DEVI V, “PHARMACEUTICAL
ENGINEERING ( PRINCIPLES AND
PRACTICES), VALLABH PRAKASHAN,
2001, PG.NO. 153-158 .
• SCHLESINGER M, DAVENPORT W,”
EXTRACTIVE METALLURGY OF COPPER
,5TH EDITION, 2011.
• WWW.SCIENCEDIRECT.COM