How do you choose an impeller type?
The size of vessel used for mixing will determine the diameter of the impeller. A general rule of thumb for axial or radial flow patterns is the diameter of the impeller be ⅓ of the vessel’s diameter, so a 10 cm beaker would require approximately 3 cm impeller.
What is the difference between high shear and low shear?
High shear, or very forceful, mixing processes uses high-speed impellers, and low shear mixing processes use flow, turbulence, and rotational force to combined miscible goods.
Which mixer works with high shear stress?
Ultra-high-shear inline mixers The mixer is designed to subject the product to higher shear and a larger number of shearing events than a standard inline rotor–stator mixer, producing an exceptionally narrow particle-size distribution. Sub-micrometre particle sizes are possible using the ultra-high-shear technology.
What is high shear dispersion?
High shear dispersion works when particles contact a rotating dispersion blade and are broken apart. The process requires equipment with high RPM and HP in order for the dispersion blade to reach tip speeds of 2,500 to 5,000 feet per minute. The optimum action of a disperser is a combination of rotary and radial flow.
What are the criteria for selecting the impeller based on viscosity?
Factors to Consider When Choosing An Impeller Vessel size. Viscosity of the material you’re working with. Desired outcome of the application, for example, aeration or high shear.
What is a high shear pump?
Model HSP – high shear pump The high capacity HSP model is ideal for inline blending, product smoothing, and de-agglomerating poorly dispersed powders. Wet milling of friable solids in suspension is even possible. The self-pumping design of the rotor and stator elements eliminates the need for a separate process pump.
What is a Cowles blade?
A Cowles blade is a high shear disc-type impeller, but other impellers include low and medium shear types. An example of a low shear impeller is the mixing propeller, while an axial flow turbine is a medium shear impeller.
Why is shear mixer high?
Primarily used for flow-controlled processes with higher viscosities, the blade edges provide higher shear and require greater horsepower to drive them. High shear mixing is utilized for ingredients that resist blending easily.
What are the 3 types of impellers?
The impeller of a centrifugal pump can be of three basic types:
- Open impeller. Open impellers have the vanes free on both sides.
- Semi-open impeller. The vanes are free on one side and enclosed on the other.
- Closed impeller. The vanes are located between the two discs, all in a single casting.
Which type of impeller is most efficient?
Closed Impellers have vanes that are “sandwiched” between two solid, circular plates. The liquid travels through the channels between the impellers and between the plates. This design creates the most efficient flow from the eye to the discharge port.
What is high shear granulation?
High shear granulation is a shaping process for granulation that has been enhanced for application in the pharmaceutical industry. A binder liquid is fed to the powder particles in a closed container with blending tools and a chopper. Dense granules are formed through the liquid and solid bridges that result.
What is chemical engineering mixer?
Mixing is performed to allow heat and/or mass transfer to occur between one or more streams, components or phases. Modern industrial processing almost always involves some form of mixing. Some classes of chemical reactors are also mixers.