2. Introduction
•It is one of the mechanical separation based on particle size which is
subjected to a force moves it to pass the retained particles.
Driving Force
Rate of Filtration: -------------------
Resistance
3. The basic requirements for equipments in filtration
•Mechanical support for filter medium.
•Flow access to and fro from the filter medium.
•Precision for removing excess filter cake.
•For this filtration come of the instruments used are
1. Plate and frame filter press
2. Rotary filter
3. Cross flow filtration
4. Air filters
4. The rate of filtration depends on
•The properties of filtrate, particularly its viscosity and density.
•The nature of solid particles, particularly their size and shape, the size
distribution and packing characteristics.
•The solid : Liquid ratio.
•The scale of operation.
•The need for batch or continuous operation.
•The need for pressure or vacuum suction to ensure an adequate flow
rate of the liquid.
5. The most commonly used filter aids are
•A thin layer of kieselguhr is applied to the filter to form a pre-coat
prior to broth filtration.
•The appropriate quantities of filter aid is mixed with the harvested
broth.
•When vacuum drum filters are to be used which are fitted with
advancing knife blades, a thick pre-coat filter is initially built upon the
drum.
