Static Mixing
A static mixer is a device for mixing two fluid materials based on flow through a tube containing elements. Each element acts as a knife splitting the streams. Twisted elements also promote further mixing by twisting flows. (RDC 7/20/2009)
“A static mixer is a series of fixed, typically helical, elements enclosed within a tubular housing. The fixed geometric design of the unit can simultaneously produce patterns of flow division and radial mixing.”
“Flow Division in a static mixer is a function of the number of elements in the mixer. Flow Division: In laminar flow, a processed material divides at the leading edge of each element of the mixer and follows the channels created by the element shape. At each succeeding element, the two channels are further divided, resulting in an exponential increase in stratification. The number of striations produced is 2n where 'n' is the number of elements in the mixer.”
Recent US Patents
3/8/2011
7,901,128
Tapered aperture multi-tee mixer
Gehrke, Gillis and Hai of Dow, Michigan, developed an static mixer for mixing and reacting fluids. This device includes a fluid receiving chamber, a first conduit passing through the fluid receiving chamber and a tapered opening and a second conduit connected to the fluid receiving chamber. (RDC 9/16/2011)
Recent Journal Articles
1/7/2011
HYDRODYNAMICS OF LIQUID FLOW THROUGH SCREENS AND SCREEN-TYPE STATIC MIXERS
(726 – 742) Chemical Engineering Communications 198 #5 (2011)
Aziziand Al Taweelof Dalhousie University, Canada have developed a method for predicting the spatial variation of the energy dissipation rate downstream of a screen. It is based on extending the use of the homogeneous and isotropic turbulence decay equation to the very thin anisotropic region adjacent to the screen. This approach was found to be capable of predicting the experimental energy dissipation data obtained using liquid flow through screens and screen-type static mixers reasonably well over a wide range of design and operating conditions. (RDC 1/6/2011)