Principle:
Silverson mixer emulsifiers produce intense shearing force and turbulence by the use of high-speed rotors.
This turbulence causes the liquids to pass through fine space formed by closely placed perforated metal sheets.
Circulation of material takes place through the head by the suction produced in the inlet at the bottom of the head.
Circulation of the material ensures the rapid breakdown of the dispersed liquid into smaller globules.
Construction:
It consists of long supporting columns connected to a motor that gives support to the head.
The central portion contains a shaft, one end of which is connected to the motor and the other end is connected to the head.
The head carries turbine blades.
The blades are surrounded by a mesh, which is further enclosed by a cover having openings.
Working:
The emulsifier head is placed in the vessel containing immiscible liquids (or coarse emulsion) in such a way that it should get completely dipped in the liquid.
When the motor is started, the central rotating shaft rotates the head, which in turn rotates turbine blades at a very high speed.
This creates a pressure difference. As a result, liquids are sucked into the head from the center of the base and subjected to intense mixing action.
Centrifugal forces expel the contents of the head with great force through the mesh and onto the cover.
As a result, a fine emulsion emerges through the openings of the outer cover.
The intake and expulsion of the mixture set up a pattern of circulation to ensure the rapid breakdown of the bigger globules into smaller globules.
Uses:
Silverson mixer is used for the preparation of emulsions and creams of fine particle size.
Advantages:
Silverson mixer is available in different sizes to handle liquids ranging from a few milliliters to several thousand liters.
It can be used for batch operations. It is also used for continuous operation by incorporating into a pipeline, through which the immiscible liquids flow.
Disadvantages:
Occasionally, there is a chance of clogging of the pores of the mesh.
Foaming.
Commonly Asked Questions:
Define Mixing. With help of a diagram describe the principle, construction and working of the Silverson Homogenizer.
Write a short note on Silverson Homogenizer.