Page 366 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

334 Applied Process Design for Chemical and Petrochemical Plants

Patent pending). Some designs work well on mixing pow- men ts (see Figures 5-42, 5-43, 5-44A & B, 5-45, 5-46 and 5-
ders. There are over 30 different models of static mixers 47) causing the flowing fluid elements to split, rearrange,
worldwide [38]. recombine and split again and repeat the process "x"
The concept of the motionless mixer is to achieve a times until a uniform or homogeneous flowing stream is
uniform composition and temperature distribution in flu- produced at the discharge. The pressure drop varies with
ids flowing through the device. Originally, this objective the mixer elements design, number per unit length, fluid
dealt with molten polymer mixing, as an alternative to the flowing ( density and viscosity). The shear on the fluid car-
dynamic mixing of an extruder screw [38]. The units are ries forward the mixing process.
now used widely for just about all fluid mixing, blending, The better mixing occurs under turbulent flow condi-
dispersion, etc., by multiple splitting of the flowing tions.
streams. The concept is built around a stationary, rigid
element placed in a pipe or cylinder that uses the energy Residence time in the units can be varied or adjusted,
of the fluid flowing past to produce the mixing. The unit which makes them suitable to serve in certain types of
becomes more efficient by adding additional static ele- reactions.

KOCH M s Static Mixing Elements For Every Application

on

Figure 5-42. Several types of static mixing elements usually adapted into pipe or fabricated casings. By permission, Koch Engineering Co.