Principle of Static mixing
Principle of mixing is nothing but continuous mixing of fluids using static mixers having no moving parts. Pumps and blowers are used to deliver components to be mixed at the desired volumetric flow rates and also to supply the pressure required for mixing. Typical sizes of static mixers vary from small laboratory sized units to large mixers which fit into large ducts used in power plants.
Static mixers consist of individual mixing elements stacked in series. Each element is oriented 90 degrees to the adjacent mixing element to create homogeneous mixing in vertical and horizontal directions. The static mixing elements divide and recombine the feed components so that the stream which exits the mixer is homogeneous with regard to concentration, temperature and velocity which are equalized throughout the entire pipe cross-section.mixing reliability. They can be easily installed, cleaned and maintained.
In case of two miscible liquids in laminar flow, the main mechanism in a static mixer is flow division. The elements are helical or pseudo-helical and are arranged in a series of alternating left and right hand 180 twists. The elements split the fluids entering in two streams and than rotate them through 180 degrees. The elements are in series in the mixer. As the number of streams or layers increases, the layer thickness decreases. Typically, 12 to 24 elements are required to provide a complete mix.
Static mixer units is constructed of a number of right and left-hand helices. These elements are alternated and originated so that each leading edge is at 90 to the trailing edge of the one ahead. In general, the length of the individual element is approximately 1.5 diameters.
Benefits of Static mixer
- Static mixers deliver a high level of mixing efficiency, therefore the consumption of dosed chemicals and formation of byproducts can be dramatically reduced.
- They eliminate the need for tanks, agitators, moving parts and direct motive power and they allows to gain highly efficient mixing with low energy consumption.
- The energy required for mixing is efficiently extracted as pressure drop from the fluid flow through the elements. Mixers are invariably installed in existing systems without reducing the capacity of existing pumps.
- The installation is very easy, no special skills are required other than normal engineering skills.
- Mixers have no moving parts and are virtually maintenance free
- Static Mixers are available in all standard pipe sizes and, in the case of open channel designs, are available in any size with no upper limit.
Number of Elements
Mixer Design, Technical Factors
- Characteristics of the mixing elements
- Technical specifications
- Surface finish static mixers
- Applied flanges & connectors