Ⅰ. Solid-liquid separation and filtration

Solid-liquid filtration separation the main principle is to use porous media or filter material to intercept solid particles, the liquid in the driving force (pressure, gravity, centrifugal force, etc.) under the action of the filter through the material, so as to realize solid-liquid separation. Its filtration mechanism can be divided into the following categories according to the way of intercepting the flow:

1.Surface Filtration

·Principle: When the liquid carries solid particles through the metal cartridge, particles larger than the pore size of the cartridge are directly retained on the surface of the cartridge, forming a cake layer.

·Application: Drilling fluid filtration in petroleum industry, chemical slurry pretreatment.

·Characteristics: Suitable for high efficiency interception of large particles (>10μm). Cake layer can improve the filtration precision, but it needs regular backwashing or mechanical cleaning.

2.Depth Filtration

• Principle: Metal sintered filter element has a porous structure, tiny particles in the liquid are captured due to inertial collision, adsorption or diffusion when they flow through the twisted pores inside the filter element.
• Characteristics: It can intercept submicron particles (0.1-10μm). High dirt-holding capacity, suitable for liquids with high solid content.
• Application: Fine filtration of drug solution in pharmaceutical industry, clarification of food and beverage.

3.Electrostatic Adsorption

• Principle: Some metal cartridges are electrostatically charged through special treatment (e.g. surface modification or coating) and can attract charged particles (e.g. colloids, microorganisms).
• Characteristics: Improved capture efficiency for small particles (<1μm).
• Application: High purity liquid filtration (e.g. ultrapure water for electronics industry).

  The key influencing factors in solid-liquid filtration and separation are as follows:

• Filter media properties: pore size, porosity, chargeability.
• Particle properties: particle size distribution, shape, hardness (sharp particles may clog the filter media).
• Operating conditions: pressure differential, temperature, filtration time, suspension concentration and viscosity, etc.

ⅡNanjing Shinkai Filtration-Solid-liquid separation solutions

The metal filtration membranes and precision filtration systems produced by Nanjing Shinkai Filter Co., Ltd. have diversified applications in the field of solid-liquid separation, such as the filtration of precious metal catalysts in the hydrogenation process, the filtration of fine silica powders in the polysilicon industry, the filtration of food and beverages, and the filtration of activated carbon. SCHUNKEY provides dead-end filtration for batch production and staggered flow filtration system for continuous production, which effectively solves many filtration and separation problems encountered by customers in the production process.

The dead-end filtration system can be divided into filtration from the outside in and filtration from the inside out. In filtration from the outside in, solids are left on the outer surface of the cartridge, and the surface cake is removed by backwashing, which is simple to use and easy to maintain, and can provide a reliable and long-lasting filtration capacity, and is suitable for the complete separation of all kinds of precious metal catalysts from the mother liquids in the production of fine chemical industry; in filtration from the inside out, solids are left on the inner surface of the cartridge, and can be separated from the mother liquor after each filtration cycle, which is suitable for the production of fine chemical industry. At the end of each filtration cycle, solid particles can be discharged from the inside of the metal membrane by means of backwashing, eliminating the problems associated with cake buildup, reducing the frequency of backwashing, and prolonging the time the filter can be used on-line, and it is suitable for the filtration of recovered precious metal catalysts, activated carbon, and catalyzed oil slurries with organic salts.
Cross-flow filtration systems utilize metal membrane cartridges as the filtration media. The system provides inside-out filtration with the performance of providing a continuous filtration cycle through cross-flow filtration. Material flows through the cartridges with openings at both ends, the filtrate exits the filtration system through the porous cartridges, and solid particles are retained in the recirculation stream. This method is suitable for filtration of materials with special particle characteristics or where continuous reaction production is required to maximize the retention of valuable solids, such as precious metal catalysts.

If you have a need for solid-liquid separation, you can communicate with us about the process or visit the official website to provide us with a parameterized form for the filtration conditions. Shinkai will specialize in customizing full-process system solutions for you, including but not limited to filter design selection, process design, instrumentation and valve selection, piping design and so on. Please feel free to contact us!