Industrial mixers serve to put fluids in motion in order to achieve a specific result. For the blending of fluids, the result could be complete homogeneity within a specified time period. For solid suspension, the result could be to suspend 85% of the solids just off the tank bottom or higher, with the largest solids suspended on the tank bottom. A dispersion process could be defined by wetting out powders that generally don't have an affinity for a solvent, such as water.
Industrial Mixers are also used to physically intensify chemical reactions in liquids, particularly the process of gas and solid mass transfer. Sediment, waste water and anaerobic processes usually involve gas dissolution. Mixing prevents small bubble from reforming and also enhance mass transfer by promoting the bubbles movement throughout the vessel.
Industrial Mixers are generally classified by how the generated power or energy of the mixer is split into flow and fluid shear (analogous to the head developed by a pump). This classification is generally characterized by the impeller , prop, or propellers flow pattern that they produce. So a vertical discharge low shear impeller, such as a hydrofoil, would promote high flow and is applied to applications such as blending, solid suspension and flocculation. A high shear homogenizer or dispersers, is a relatively high shear device with relatively poorer flow characteristics but they can be used in combination with high flow devices such as that seen with gas-liquid fermentors or fermentation. There are numerous other impeller designs that fall mid-range in both flow and shear with typical applications such as chemical mixers, emulsions, flash or rapid mixing, neutralization applications, slurry or slurries suspensions, heat transfer, clay blungers, make-down, slip or storage, which encompass both batch and continuous applications. It is for this reason that Industrial Mixers and agitators are classified by the specific action caused by these impellers upon the liquid media.
Lower speed gear reduced mixers turbine mixers are used for general purpose mixing applications. These turbine mixers are applied to open tank designs with support beams that span the tank, or with various closed tank designs such as low pressure stuffing box or high pressure (or vacuum) mechanical seal designs.
Other classifications of mixers include Lab Mixers, Portable Mixers, moderate mixers and what are generally referred to as the heavies. Lab mixers are generally obtainable through science trade catalogs and are generally 1/6 horsepower or less. The heavies mixer are generally classified by both high price and an agitator shaft diameters greater than 3.0" in diameter. Moderate industrial mixers are generally classified as small turbine mixers with agitator shafts from 2" to 3" in diameter. Portable mixers, many of which are too heavy to carry, are classified rather by shafts diameters up to 1-3/4" in diameter. Economy direct and gear driven as well as heavy duty gear driven designs fall under the portable mixer classification.
These portable Mixer designs include: