Silverson emulsifiers mix or homogenize coarse particles in the emulsion and suspension, reducing them to fine particles. Its capacity ranges from 1 ml to 12 lt, and its ability to mix in-line with flow rates is up to 20 lt/min.
Principle
Silverson emulsifier works on the principle of shearing forces and turbulence produced by the high-speed rotors.
The fluid passes through fine spaces formed by closely placed perforated metal sheets under turbulence.
The material circulates through the head by the suction produced in the inlet at the head bottom.
The dispersed fluid rapidly breaks down into smaller globules as the material circulates.
Construction
Silverson emulsifier consists of long supporting columns connected to a motor providing support to the head
It has a centrally located shaft with one end connected to the motor and the other to the head.
Turbine blades are present in the head.
These blades are surrounded by a mesh enclosed by a cover having openings.
Working
Immerse the head of the Silverson emulsifier completely in the vessel containing immiscible fluid or coarse emulsion.
On starting the motor, the central rotating shaft rotates the head at a very high speed, which further rotates the turbine blades at the same speed; thus creating a pressure difference.
As a result, the head sucks fluid from the center of the base and subjects it to intense mixing action.
Centrifugal forces forcefully expel the contents of the head through the mesh and onto the cover, resulting in the obtention of a fine emulsion through the openings of the outer cover.
Ø This intake and expulsion of mixture set up (such a circulation pattern) rapidly breaks the bigger globules into smaller ones.
Application
It is used for mixing creams, ointments, sauces, flavoring emulsions, and pharmaceutical suspensions with globule or droplet sizes ranging from 2-5μ.
Merits
It is available in different sizes, thus making handling liquids ranging from a few milliliters to several thousand liters possible.
Its mixing action reduces the processing and mixing time by up to 90%.
Demerit
- It may clog the pores of the mesh.
- It consumes high operating power.
- It requires high shear force.