- Filtration Objectives, applications, Theories & Factors influencing filtration, filter aids, filter medias. Principle, Construction, Working, Uses, Merits and demerits of – Plate & frame filter, Filter leaf, Rotary drum filter, Meta filter Cartridge filter, Membrane filters & Seidtz

1. Filtration
By
Yogeshwary Bhongade
Assistant Professor
Gondia college of Pharmacy, Gondia

2. UNIT-IV
1- Filtration
• Objectives, applications, Theories & Factors influencing filtration, filter
aids, filter medias.
• Principle, Construction, Working, Uses, Merits and demerits of –
Plate & frame filter,
Filter leaf,
Rotary drum filter,
Meta filter
Cartridge filter,
Membrane filters &
Seidtz

3. Filtration
• It is the process of separation of particle from
fluid by passing slurry through a permiable
membrane.
Slurry- Suspention of particle in Liquid
Filter Medium-Medium through which slurry
passed
Residue- Separated solid on medium
Filtrate- Clear liquid passing through medium

4. Objectives
• For clarification
• Cake filtration
• Sterile Filtration
• Ultra filtration

5. Applications
• Fitration of bacteria and particulate contamination
• Sterilization of heat labile solution
• Separation of bulk product from reaction mixture
• purification of water
• Removing of solid or suspended olis from aqueous solution
• Separation of alcohol from fermentation reactor
• Treatment of waste liquid

6. Mechanism of filtration
1. Staining
2. Impringment
3. Entanglement
4. Electrostatic force

7. Filter Media
• It is the medium through which slurry is passed to get filtrate
or
• The surface on which solids are retained after filtration process is
called as Filter Medium.

8. Properties of Ideal Filter Media
• Sufficient Mechanical Strength
• Chemically inert
• Minimum resistance to flow filtrate
• High retention power
• Should allow easy removal of cake
• Should not absorb dissolved material
• Not swell in contact with filtrate

9. Selection of Filter Media
• Selection of Filter Media Depends on following
• Size of Particles to be filtered
• Nature of Product to be filtered
• Amount of liquid to be filtered

10. Filter Media
1. Woven Mendia
- Cotton Cloth
-Nylon Cloth
- Woven wire cloth
2. Non Woven Media
3.Membrane filter
4. The depth type Media
- Fibrous Medium
- Porous Medium
- Bed of Granular solid

11. Filter Aid
• Special type of filter medium, which form a fine surface deposite that
form porous, non- compressible cake over filter medium, thus
reducing resistance to flow
• Act as depth filter
• Maintain Flow

12. Ideal Filter Aid
• Should form porous cake
• Suitable particle size
• Impurities free
• Free from moisture
• Should be innert
• Should maintain suspended
Precoating
Body Mix

13. Filtration Equipments
Classificaton Based on Type of Driving Force

14. • Classification Based on Type of Operation
Type Of
Operation
Batch Continuous

15. • Classification Based on End Product
Based on
End Product
Filter Cake
Clarifying
Filter

16. • Choice of filter govern by specific requirement
1. Properties of Liquid eg. Viscosity
2.Objectives of Filtration eg. Recovery of solid/ sterilization/clarification
3.Properties of solid eg. Particle size, shape, compressibility
4.Whether Cake is to be washed
5.Operating Temperature and Pressure
6. Desired flow rate

17. Plate & frame filter
Principle
• Based upon surface filtration
• the slurry enters the frame by pressure and flows through the filter
medium.
• The filtrate is collected on plates and sent to outlet
• surface area increased with the help of plate and frames then large
volume of slurry can be proceed
• The Filter press is made of two types of units, plate and frames.

18. • Usually made of aluminium alloy.
• Sometimes, these are also lacquered for protection against corrosive
chemicals and made suitable for steam sterilization.

21. Frame
• It contains a open space inside wherein the slurry reservoir is
maintained for filtration and an inlet to receive the slurry.
• It is indicated by two dots in description. Slurry inlet Handle to rest on
rod
• Frames of different thickness are available.
• It is selected based on the thickness of cake formed during filtration.
• Optimum thickness of frame should be chosen.

22. Plate
• The plate has a studded or grooved surface to support the filter cloth and
an outlet. It is indicated by one dot in description. Through channels
Filtrate outlet
• Plate supports the filter medium, receiving the filtrate and outlet.
• The filter medium usually cloth is interposed between plate and frame.
• Plate, filter medium, frame, filter medium and plate are arranged in
sequence and clamed to a supporting structure.
• It is normally described by dots as 1.2.1.2.1 so on.
• A number of plates and frames are employed so that the filtration area is
as large as necessary.
• ts controlled by valves.

23. • Number of filtration units are operated in parallel.
• Channels for slurry inlet and filtrate outlet can be arranged by fitting
eyes to the plates and frames, these join together to form a channel.
• In some types only one inlet channel is formed, while each plate is
having individual outle

24. Working of filter press
• Working can be divided into two steps-
1. Filtration operation
2. Washing operation Filtration operation

25. Advantages:
1- Construction is very simple and a wide variety of materials can be
used.
2- It provides a large filtering area in a relatively small floor space. 3- It
is versatile, the capacity being variable according to the thickness of the
frames and the number used.
4- The construction permits the use of considerable pressure difference.
5- Efficient washing of the cake is possible.
6- Operation and maintenance is straightforward , because there no
moving parts, filter cloths are easily renewable and, because all joints are
external, any leaks are visible and do not contaminate the filtrate.

26. Disadvantages:
1- It is a batch filter, so it is a time consuming.
2- The filter press is an expensive filter, the emptying time, the labour
involved, and the wear and tear on the cloths resulting in high costs.
3- Operation is critical, as the frames should be full, otherwise washing
is inefficient and the cake is difficult to remove.
4- The filter press is used for slurries containing less about 5 % solids
5- In view of the high labour costs , it is most suitable for expensive
materials.e.g.the removal of precipitated proteins from insulin liquors.

27. Filter leaf
• It is the simple form of batch filter
consisting of dranage canal converted
with filter cloth
Principle
• Surface filtration
Construction
• It consist of grooved metal frame work
over which filter cloth is fixed.
• The groved frame encloses drainage
screen.
• The outlet for filtrate connected to inside
the frame.

28. Working
• The filter leaf is placed in a vessel containing the liquid to be filtered.
• When vacuum is applied , the pressure inside the leaf is decreased.
• Due to the difference in external and internal pressure inside the leaf,
the liquid moves inside the filter through the filter cloth.
• The filtrate is collected in the receiver , and cake gets collected on
outside of the cloth.

29. Advantages:
Liquid can be filtered from any vessel .
Filter cake can be removed simply by washing or blowing air.
It is very economical .
Disadvantages :
It is not effective when solid content in the liquid is more than 5%.

30. Meta filter
Also known as Edge filter
Principle
• It fuction as surface filter and separate the particle by staining through the
tappering channels formed by series of ring with semicircular projection.
Construction
• It is made up of a series of metal ring made of ss packed on grooved rod.
• ring have internal diamete 15 mm and external diameter 22mm

32. Working
• The entire assembly is placed inside a pressure vessel , containing the
liquid to be filtered.
• When vacuum applied, liquid will flow from outside to inside.
• The clear liquid is collected in to a receiver from the top.
• The pack of rings acts as a base on which the true filter medium is
supported.

33. Advantage
• It possess considerable strength and hence can withstand high
pressure.
• It is economical.
• The corrosive liquids can be filtered without any problem.
• Cake can be removed effectively without any difficulty.
Use
• Used mostly for clarification of syrups , elixirs and parenteral
solutions .

34. Rotary drum filter
• Rotary drum filter is continuous filter that can handle slurries with high
proportion of solid, with simultaneously removal of cake.
• It operate on vacuum
Construction
• It consist of hallow metal cylinder on which filter cloth is mounted with
support of mesh.
• the cylinder has five sections-
1.Pickup zone
2.Drainage zone
3. Washing zone
4. cake removal zone
5. Drying zone

36. Working
• The drum rotate slowly and pickup slurry from the feed through
(pickup zone).
• The slurry is filtered under vacuum and the cake built on the filter
cloth.
• From the fewatering zone the water is completely removed from cake.

37. Advantages
• Automatic and continuous
• low labor cost
• Can handle large ammount of slurry
• Speed of drum can varry to control the thickness of cake
Disadvantages
• Difficult to maintain as it contain may moving part
• Cake may crack due to vacuum, making washing difficult
• Small pressure difference(liquid may boil)
• not suitable for gelatinous solids.

38. Membrane filters
Construction
Membrane filters are made of thin and flat membranes of cellulose derivatives,
such as cellulose acetate and cellulose nitrate.
• Thickness: 50-150 µ
• 400-500 million pores
• Pores are uniform in size and occupy 80% of filter volume.
• A membrane filter is fixed in a metallic holder before its use.
• Selection of membrane filter depends on particles to be removed.
• Pore size (in µ) Particles removed 0.2 All bacteria 0.45 All coliform group
bacteria 0.8 All air born particles 1.
• All Non living particles considered dangerous in I.V. Fluid. 5 All Significant
cell from body fluid 4. Membrane Filters 12

39. Advantages
• The processes can function effectively at low temperatures.
• Energy requirements are low.
• Processes are relatively simple to scale up.
• Membranes can be manufactured in a uniform and highly precise manner.
Disadvantages
• It cannot be used for filtration of organic solvents, such as alcohols, ketones,
esters and chloroform.
• Pre-filtration is often required to avoid rapid clogging of a membrane.
• Equipment cost can be high.
• If the membrane manufacturing process is not precisely controlled, membranes
with wide pore size distribution may result, giving poor separation
performance.
• Uses Mainly used for sterilisation of both aqueous and oily liquids

40. Cartridge filter
Principle
• The principle behind this filter is water is pushed through thin porous membrane
in which pre-filter and membrane filter are combined into the single unit.
• as a result the particals are retained on the surface
Construction
• it consist of cylindrical centrifugation having disposable filter media which are
made up of platic or metal.
• The filter consist of cartridge one of which act as prefilter while another one act
as actual filter for filtration.
• The cartridges are enclosed in holder. There is also provsion for slurry and
filtrate outlet.
• At the bottom discharge cake is collected which is removed from bottom.

41. Working
• A slurry is pump into cartridge holder
through the inlet. it passes through
cartridge filter.
• The filtration occures due to mechanism
of staining.
• The particle get attached to the surface
while clear liquid passes to the centre
• The filtrate ove up and collected
through the outlet

42. Uses
• Preparation of sterile solution(Parentral and opthalmic)
• Water treatment plant

43. Advantages
• Suitable for sterile preparation.
• low contamination
• easy to dissasemble
• Filter media can be reused
• cartridge with self cleaning devices are useful
• cartridge are not brittle, whwn they dry.
• Can use continuous

44. Disadvantages
• To much cost

45. Seitz filter
Principal
• Filtration of asbestos pad filter disc
Construction
• Funnel like structure.
• Upper part
• Asbestos pad filter disc
• Lower part

46. Working
• Join parts then add slurry.
Slurry deposit on asbestos pad filter disc and Filtrate will pass.
Application
• Serum sterilization.
• Sterilization.
Advantages
• Contaminate filters
• Simple to use
• Useful for viscous solutions.
Disadvantages
• delicate

47. THANK YOU