Introduction to the principle of static mixer

1、 [Structural characteristics, mixing principle]
The mixing process of a static mixer is carried out by a series of mixing units of different specifications installed in hollow pipes. Due to the action of the mixing unit, the fluid is sometimes left turned and sometimes right turned, constantly changing the flow direction. This not only pushes the central liquid flow towards the periphery, but also pushes the surrounding fluids towards the center, resulting in a good radial mixing effect. At the same time, the rotational action of the fluid itself also occurs at the interface between adjacent components, and this perfect radial circulation mixing effect achieves the goal of uniform mixing of materials.
This static mixer is designed, manufactured, and accepted according to the industry standard JB/T7660-95 "Static Mixer".
Static mixers can be applied to processes such as liquid-liquid, liquid gas, liquid-solid, and gas gas mixing, emulsification, neutralization, absorption, extraction, reaction, and enhanced heat transfer. They can be used in a wide range of viscosity and different flow patterns (laminar, transitional, turbulent) for intermittent and continuous operations. Below is a brief introduction to the scope of different application scenarios.
(1) Liquid-liquid mixture
From laminar to turbulent flow, fluids with viscosity in the range of 106mPa · s can achieve good mixing. The minimum diameter of dispersed droplets can reach 1-2 μ m, and the size distribution is uniform.
(2) Liquid gas mixture
Static mixer can continuously update and fully contact the phase interface of liquid gas two-phase components, and can replace bubble column and sieve plate column under certain conditions.
(3) Liquid-solid mixture
When a small amount of solid particles or powder (solid accounts for about 5% of the liquid volume) are mixed with the liquid under turbulent conditions, using a static mixer can force the solid particles or powder to be fully dispersed, achieving the requirements of liquid extraction or decolorization.
(4) Gas air mixture
Can be used for mixing cold and hot gases, as well as mixing different gas components.
(5) Enhance heat transfer
Due to the static mixer, the contact area of the fluid is increased, which increases the heat transfer coefficient. Generally speaking, for the cooling or heating of gases, if a static mixer is used, the heat transfer coefficient of gases can be increased by 8 times; For the heating of viscous liquids, the heating coefficient can be increased by 5 times; When a gas with a large amount of non condensable gas is condensed, the heat transfer coefficient can be increased by 8.5 times; The heat transfer of polymer melt can reduce the temperature and viscosity gradient of the melt on the pipe section.
2、 [Precautions]
Engineering design generally uses a single or series static mixer to achieve the mixing purpose. If two static mixers are operated in parallel, the piping design should ensure even fluid distribution.
When using small-sized SV type, if the medium contains impurities, two parallel switching filters should be installed before the mixer, and the filter size is generally selected as a 40-20 mesh stainless steel filter.
Try not to install flow, temperature, pressure and other indicator instruments and detection points on the static mixer as much as possible. If there are special requirements, provide drawings and instructions when ordering.
When it is necessary to install a heat exchange jacket on the mixer casing, it should be specified at the time of ordering.
For SH series products, due to their high processing accuracy and difficult maintenance, it is required to use media that are clean or can be inverted and cleaned with solvents, or media that can melt at high temperatures.
For SV series products, if the blockage is caused by unclean fluid, the equipment can be disassembled and cleaned upside down with water (steam) or solvent. The unit can also be dismantled to remove the blockage.
For non fixed unit products in the SK series, the entire unit can be removed for cleaning, but be careful not to tap it when pulling it out to avoid deformation of the unit.
Normally, for different usage requirements, as long as the product specifications, models, and materials are correctly selected, our company's static mixer can avoid maintenance.