Static mixers viscous materials

When it is deleterious, laminar flow can be avoided by mixing over the cross section. For this purpose static mixers in line can be provided. For very viscous materi s and pastes, screws of the type used for pumping and extrusion are used as reactors. 

Figure 7.29 shows a Sulzer type SMX static mixer where the mixing element consists of a lattice of intermeshing and interconnecting bars contained in a pipe 80 mm diameter. It is recommended for viscous materials in laminar flow. The mixer shown is used in food processing, for example mixing fresh cheese with whipped cream. 

Static mixers for viscous fluids are widely used in processes producing polymers, fibres and plastics of all kinds where the materials tend to be viscous, hot and often at high... 

A number of innovative polymerization reactors using loop reactors, plug-flow and static mixer reactors, and continuous stirred-tank reactors have been reported. For example, Wilkinson and Geddes (15) describe a 50-liter reactor that has the same capacity as a 5000-gallon batch reactor. Extruders, thin-film evaporators, and other devices designed to provide intense mixing for viscous or unstable materials have also been used as reactors. 

Motionless mixers are an alternative to rotating impeller mixers. Motionless or static mixers use stationary shaped elements inside pipes or conduits to divide, divert, twist, and recombine flowing material. The dividing, stretching, and recombining processes lead to thinner and thinner striations in viscous materials to achieve uniformity. 

In the continuous process, most mixing operations are achieved with static mixers only highly viscous or difficult materials are mixed with dynamic mixers. 

The valves are based on the company s Micro-Kiss No-Drip valve body design for low-flow fluid control using bayonet-style static mixers. The No-Drip design feature integrates carbide ball-end needles with carbide seats for long life dispensing of viscous and abrasive materials. 

Figure 8.38 Static mixer for viscous Newtonian and non-Newtonian materials...

Gramann, P.J., Davls, B.A., Osswald, T.A., Rauwendaal, C.J., A New Dispersive and Distributive Static Mixer for the Compounding of Highly Viscous Materials, SPEAN-TEC (1999)... 

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