Functions And Working Principles of Cartridge Filter

Cartridge filter, also known as precision filter, plays a vital role in water treatment systems and other fluid handling systems. Below is a detailed explanation of its functions and working principles:

I. Functions of Security Filter

Removal of Particulate Impurities cartridge filter can effectively trap suspended particles, colloids, microorganisms and other impurities with diameters larger than the pore size of its filter element (typically 5 microns), ensuring water purity. This helps reduce physical contamination of downstream equipment such as reverse osmosis (RO) membranes, ion exchange resins and ultrafiltration (UF) membranes.

Protection of Downstream Equipmen tAs a pre-treatment device, cartridge filter significantly lowers the particle load entering subsequent precision treatment units (e.g., reverse osmosis systems, nanofiltration systems, electrodeionization systems). It prevents contaminants from clogging, abrading or fouling critical components, thereby extending their service life and reducing maintenance costs.

Guarantee of Stable System Operation By eliminating micro-impurities that may trigger chemical reactions, biological activity or scaling, cartridge filter helps maintain the stable operation of the entire water treatment system. This avoids water quality deterioration or reduced treatment efficiency caused by impurities.

Meeting Specific Process RequirementsIn industrial production or laboratory applications with strict water quality standards, cartridge filter can serve as the final precision filtration step. It ensures that the effluent water quality meets the specified particle control standards, satisfying the requirements of specific processes.

II. Working Principles of Precision Filter

The working principle of cartridge filter is based on mechanical filtration, and the specific process is as follows:

Filter Medium Cartridge filter uses filter elements as the filtration medium. These elements can be made of various materials, including polypropylene (PP) melt-blown filter elements, string-wound filter cartridges, and pleated filter elements. Each type of filter element has a specific pore size, with the commonly used one being 5 microns (μm).

Pressure-Driven Filtration During operation, the fluid to be filtered (such as water or other liquids) is forced into the filter under a certain pressure and passes through the filter cartridge from the outside to the inside.

Mechanical Interception When the fluid flows through the filter element, suspended particles, colloids, microorganisms and other impurities are trapped on the surface or with in the pores of the filter element because their sizes exceed the pore size of the element.

Discharge of Purified FluidThe clean fluid filtered through the element permeates the filter element and is discharged from the outlet of the filter, achieving the purpose of fluid purification.

Filter Element Maintenance As the filtration process proceeds, the amount of trapped substances on the filter element gradually increases, leading to higher pressure loss of the filter. When the pressure difference between the inlet and outlet reaches a certain value (e.g., 0.1 MPa), it in dicates that the filter element is clogged. At this point, the filter element needs to be replaced with a new one to maintain filtration efficiency.

Cartridge filter plays an indispensable role in water treatment systems and other fluid handling systems. Based on the mechanical filtration principle, it effectively removes particulate impurities from fluids, protects downstream equipment from contamination and abrasion, and ensures the stable operation of the entire system.