Choosing an Agitator
All mixing impellers produce both fluid velocity and fluid shear, but different types of impellers produce different degrees of flow and turbulence, either of which may be important, depending on the application.
MGT Mixing delivers varied agitator and vessel types to meet diverse industry requirements.
Determine Impeller Size and RPM
This depends on the kind of impeller and operating conditions described by the Reynolds, Froude, and Power numbers as well as individual characteristics whose effects have been correlated. For the popular turbine impeller, the ratio of diameters of impeller and vessel falls in the range, d/D,=0.3-0.6, the lower values at high rpm, in gas dispersion, for example.
In order for power (the rate at which work is done) to be meaningful there must be a standard of comparison. The most common unit to measure linear force is horsepower which defined as the energy to move 100 pounds 330 feet in 1 minute. Mechanical transmission products such as gearboxes are evaluated on the basis of torque of rotation energy. Rotational power is defined as force times angular velocity. The angular velocity of a mixing impeller is normally measured in revolutions per minute (RPM).
The amount of torque applied to fluid mix is one of the most important factors in determining mixing results.
Torque is defined as:
Torque [Newton*meter]= (HP x 7126)/RPM