Filter leaf – Pharmaceutical Engineering B. Pharm Third Semester PDF Notes

Filter leaf


• It is an apparatus consisting
of a longitudinal drainage screen covered with a filter cloth

• The mechanism is surface
filtration and acts as sieve or strainer

• Vacuum or pressure can be
applied to increase the rate of filtration


• The leaf filter is consisting
of a frame enclosing a drainage screen or grooved plate

• The frame may be any shape
circular, square or rectangular

• The whole unite being covered
with filter cloth

• The outlet for the filtrate
connects to the inside of the frame through suction   

Filter leaf Diagram


Working and


Use  for  the 
filtration  of  slurry 
which do  not  contain 
high  solid  content, 
about  5%,  i.e. dilute suspensions


• Simplest form of filter used for batch process

• A number of units can be connected in parallel to increase
the surface area of filtration

• Pressure 
difference  can  be 
obtained  either  with 
vacuum  or  using 
pressure  up  to 
the  order  of  800

• Labour costs for operating the filter leaf are fairly

• The efficiency of washing is high

• The slurry can be filtered from any vessel

• The cake can be washed simply by immersing the filter in a
vessel of Water

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