In the static mixing business, there can be a lot of terms that can be confusing unless you are well versed in the process. This helpful guide can help guide you through static mixing literature.
Static Mixing – This is a process whereby pipes or tubes contain stationary devices that use the kinetic flow of the material to create the mixing process.
Flow – This term refers to the overall movement of the fluid being mixed.
Shear – Inversely related to the flow, the shear is a measurement of stress being produced on the fluid. Fluids with high shear will have particles that move at different velocities. A fluid with high flow would have a low shear, and a fluid with low flow would typically have a high sheer.
Flow Rate or Pumping Rate (Q) – This is a measure of the actual rate of flow generated by a specific impeller rotating at a particular speed. This rate is given in gallons per minute.
Viscosity (Cp) – Viscosity is the overall thickness of the fluid. It’s actually a measure of internal fluid friction, but thickness is an acceptable lay definition.
Specific Gravity – This represents a ratio between the density of the water and the density of another fluid.
Reynolds Number – In a mixing application, this is the magnitude of fluid motion generated. This helps calculate a power draw if the viscosity rises above that of water.
Vortexing – This is a process whereby the fluid is rapidly swirled to create a whirlpool-like vortex around the impeller, which allows ambient air to become part of the mixture. This is generally seen as a highly undesirable outcome.
Pharmaceutical Mixer – This is a specific type of mixer used to meet very exacting sanitary requirements. Often designed with stainless steel components, these mixers are used in closed-tank areas that will prevent contamination from outside sources.