High viscosity mixer

Anchor Mixers Anchor mixers are the simplest and one of the more common types of high-viscosity mixers (Fig. 18-42). The diameter of the anchor D is typically 90 to 95 percent of the tank diameter T. The result is a small clearance C between the rotating impeller and the tank wall. Within this gap the fluid is sheared by the relative motion between the rotating blade and the stationary tank wall. The shear near the wall typically reduces the buildup of stagnant material and promotes heat transfer. To reduce buildups further, flexible or spring-loaded scrapers, typically made of polymeric material, can be mounted on the rotating blades to move material physically away from the wall. 

High Viscosity Mixers. While turbine mixers can handle low to... 

Except for some portable mixers, high-shear mixers, and a few special mixers, most mixers operate below standard motor speeds. Typical motor speeds of 1800 or 1200 rpm (30 or 20 rps) are reduced to between 350 and 30 rpm (5.8 and 0.5 rps) for most mixer applications. Portable and side-entering mixers usually operate near the upper portion of this speed range from 420 to 170 rpm (7 to 2.8 rps). Turbine mixers operate in the middle range, from 125 to 37 rpm (2.1 to 0.6 rps), and high viscosity mixers operate from 45 to 20 rpm (0.75 to 0.33 rps) and slower. 

Physical Properties. The egg is composed of three basic parts shell, whites (albumen), and yolk. Each of these components has its own membranes to keep the component intact and separate from the other components. The vitelline membrane surrounds the yolk, which in turn is surrounded by the chala2iferous layer of albumen, keeping the yolk in place. Egg white (albumen) consists of an outer thin layer next to the shell, an outer thick layer near the shell, an inner thin layer, and finally, an inner thick layer next to the yolk. Thick layers of albumen have a higher level of ovomucin in addition to natural proportions of all the other egg white proteins. This ovomucin breaks into shorter fibers when the egg white is blended on a high speed mixer (3), or when the egg white ages. Viscosity is gready reduced when the egg white is blended in this way. 

In order to "cure" or "vulcanize" an elastomer, ie, cross-link the macromolecular chains (Fig. 2), certain chemical ingredients are mixed or compounded with the mbber, depending on its nature (4,5). The mixing process depends on the type of elastomer a high viscosity type, eg, natural mbber, requires powerhil mixers (such as the Banbury type or mbber mills), while the more Hquid polymers can be handled by ordinary rotary mixers, etc (see Rubber... 

These mixers are specified when one liquid must be dissolved in another, a solid and a liquid must be mixed, a high viscosity liquid must be reacted, a light liquid must be extracted from a mixture of heavy and light liquids, or when gas must be absorbed in a liquid. To select the proper mixer, certain fluid properties must be know n ... 

Kneaders, Z- and sigma-blade, and Banbury mixers as shown in Figure 7.20, are generally used for the mixing of high-viscosity liquids, pastes, rubbers, doughs, and so on. The tanks are usually mounted horizontally and two impellers are often used. The impellers... 

The concept of the internal mixer is well accepted in the rubber industry, especially for the production of masterbatch compounds. Within a variety of materials the deformation of rubber compounds is relatively difficult due to the very high viscosity. Mixing devices have to be strongly powered and have to be designed in a very robust way in order to withstand the very high forces and momentum acting on the device. The most important benefits of an internal mixer are... 

Grace, H. P., Dispersion phenomena in high viscosity immiscible fluid systems and application of static mixers as dispersion devices in such systems. 3rd Eng. Found. Conf. Mixing, Andover, N. H. Republished in Chem. Eng. Commun. 14, 225-227 (1982). 

H.P. Grace Dispersion Phenomena in High Viscosity Immiscible Fluid Systems and Application of Static Mixers as Dispersion Devices in Such Systems. Chem. Eng. Commun 14, 225 (1982). 

Mixer-settlers High-stage efficiency Handles wide solvent ratios High capacity Good flexibility Reliable scale-up Handles liquids with high viscosity Petrochemical Nuclear Fertilizer Metallurgical... 

Laminar-flow blending duties involving high viscosity ratios (greater than 1000 1) are classified as difficult. The SMX mixer appears to have the best track record in achieving satisfactory results. 

Mixer-settlers High-stage efficiency, handles wide solvent ratios, high capacity, good flexibility, reliable scale-up, handles liquids with high viscosity Petrochemical, nuclear, fertilizer, metallurgical... 

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