Tech Brief: Ultra-High Shear Mixers Increase Overall Throughput And Efficiency Of Homogenization Processes

Maximizing process efficiency during pre-mixing
Many fine emulsions and dispersions require multiple passes through a high pressure homogenizer to achieve the final droplet or particle size distribution. Operating and maintenance costs for a homogenizer are comparatively high, so the addition of an upstream mixer that can prepare a finer premix and reduce the number of passes through the homogenizer significantly reduces processing costs and sharply improves equipment utilization.

Ultra-high shear mixers vs. conventional rotor/stators
Several types of mixing systems are utilized for combining raw materials into a pre-mix. There are gentle agitation devices such as low speed propellers, turbines or paddle agitators. Better quality pre-mixes are achieved through the use of high speed devices like open-disc saw-tooth blades and high shear rotor/stator mixers. Conventional high shear mixers feature a four-blade rotor running at tip speeds in the range of 3,000-4,000 feet/min within a close tolerance fixed stator. This type of device creates mechanical and hydraulic shear by continuously drawing product components into the rotor and expelling them radially through the openings in the stator. Ultra-high shear mixers, on the other hand, operate at much higher tip speeds around.