1. Porous media filters are widely utilized in water treatment processes. While they can be employed as standalone units, they most frequently serve as pre-filters for advanced water treatment stages (such as ion exchange resins, electrodialysis, and reverse osmosis).
2. Multi-media filters are commonly used as pretreatment devices for advanced water purification; different types of filter media can be selected and loaded into the unit based on specific process requirements.
3. Multi-media filters can be constructed from various materials, including fiberglass-reinforced plastic (FRP), corrosion-resistant or rubber-lined A3 carbon steel, and full stainless steel. Operation modes are available in both fully automatic and manual configurations. The automatic control system utilizes imported controllers from the USA, coupled with pneumatic and hydraulic valves, offering ease of operation and simplified maintenance. Consequently, these filters are widely adopted as pretreatment units across water treatment processes in a diverse range of industries.
4. The filtration media used in multi-media filters (including dual-media filters) must possess sufficient chemical stability. Furthermore, there should be distinct differences in the relative density and particle size among the various media layers. For dual-layer filters composed of anthracite and quartz sand, the anthracite typically has a relative density of 1.4–1.6 and a particle size of 0.8–1.8 mm, while the quartz sand has a relative density of 2.6–2.65 and a particle size of 0.5–1.2 mm. In addition to these two materials, triple-layer filters may incorporate heavy mineral ores-such as manganese sand or magnetite-which typically feature a relative density of 4.7–5.0 and a particle size of 0.5–4 mm.
