The cleaning method for stainless steel filter elements mainly depends on the structure of the filter, its filtration precision, the nature of the filtered medium, and the degree of contamination.
Common cleaning methods can be classified into three main categories: physical cleaning, chemical cleaning, and combined cleaning.
1. Physical Cleaning Methods
These mainly rely on mechanical action or fluid impact to remove particles and impurities attached to the filter surface. They are suitable for cases where the contaminants are primarily solid particles.
Backwashing
Use clean water or process medium in the reverse direction to flush the filter, discharging impurities from the opposite side. Suitable for metal filters with backwashable structures.
Ultrasonic Cleaning
Utilizes the cavitation effect generated by ultrasonic waves in liquid to detach and break down deposits, especially effective for sintered mesh or sintered fiber filters with numerous micro-pores and gaps.
High-pressure Water Jet / Air Blowing
Uses high-pressure water flow or compressed air to directly impact the filter surface and remove large particles. Not suitable for ultra-fine precision filters with very small pore sizes, to avoid damage.
2. Chemical Cleaning Methods
Use chemical solutions to dissolve, disperse, or strip oil stains, gels, chemical deposits, and other contaminants from the filter surface.
These methods are suitable for oil-based contaminants, oxides, or inorganic deposits.
Acid Cleaning
Use dilute nitric acid, citric acid, or other acid solutions to remove oxides, scale, or metallic deposits.
Suitable for removing inorganic scale, but concentration and exposure time must be controlled to prevent corrosion.
Alkaline Cleaning
Use sodium hydroxide, sodium carbonate, or other alkaline solutions to remove oil stains, proteins, or organic deposits.
Organic Solvent Cleaning
Use ethanol, acetone, or other organic solvents to dissolve grease, resins, and other difficult-to-remove substances.
Oxidation-Reduction Cleaning
Use hydrogen peroxide, potassium permanganate, or similar agents for oxidative decomposition, suitable for specific organic deposits.
3. Combined Cleaning Methods
Combine physical and chemical methods to improve cleaning efficiency.
Chemical Soaking + Ultrasonic Cleaning
First soak in chemical solution to dissolve contaminants, then use ultrasonic agitation to remove remaining residues.
Heated Chemical Cleaning
Heat the cleaning solution to an appropriate temperature (e.g., 50–80°C) to accelerate the decomposition of grease or deposits.
Circulating Cleaning
Continuously circulate the cleaning solution inside and outside the filter element to flush away impurities.
Precautions
Before cleaning, confirm the filter’s material and chemical corrosion resistance to avoid using agents that may damage stainless steel.
Control cleaning time and temperature to prevent filter deformation or pore size enlargement.
After cleaning, rinse thoroughly to remove any residual cleaning agents.
For high-precision filters (e.g., 1–5 μm), avoid strong mechanical impact.
