The multi-layer filter material gradient design of the multi-media filter builds an efficient impurity interception system through the complementary characteristics of different materials and hierarchical coordination. This design is not a simple superposition of filter materials, but allows each layer of filter material to play a dedicated role in a specific position, forming a gradient filtering effect through material differences, and greatly improving the overall interception efficiency.
The top layer of multi-media filter filter material usually uses materials with low density and large particle size, such as anthracite. This type of material has good water permeability and can first intercept large suspended impurities in the fluid, such as silt, fiber, etc., to prevent large particles from blocking the pores of the lower filter material. Its rough surface characteristics can also capture some viscous impurities through adsorption, reducing the burden for subsequent filtration, and playing a dual role of preliminary purification and protection of the lower filter material.
The middle layer filter material is mostly made of quartz sand with moderate density and particle size to receive the fluid after filtering from the upper layer. The quartz sand has uniform particle distribution and fine pore structure, which can intercept medium-sized impurities such as colloidal particles and fine silt that have leaked through the upper layer. Its hard texture is not easily deformed by water flow impact, and it can maintain a stable pore structure during long-term use, ensuring smooth filtration channels, allowing the fluid to pass evenly and fully contact the filter material, and improving the interception rate of medium impurities.
The lower filter material of the multi-media filter uses a material with a higher density and finer particle size, such as magnetite or garnet. This type of material has a higher specific gravity and can maintain a stable layered structure under the impact of water flow. Its tiny pores can intercept tiny suspended particles and colloidal substances in the water. Because it is at the bottom of the filtration system, it can deeply purify the fluid, capture the fine impurities that are not intercepted by the first two layers, and ensure that the impurity content of the final outflowing fluid is greatly reduced.
The difference in surface properties of different materials forms a synergistic adsorption effect. The carbonaceous surface of anthracite has a strong adsorption force on organic impurities, the silicate component of quartz sand can adsorb some inorganic ions, and the magnetism of magnetite can attract iron-containing impurities. When the fluid passes through these filter media layers in sequence, different types of impurities will be selectively adsorbed by the corresponding filter media materials. This targeted adsorption allows all types of impurities to be effectively captured, avoiding the problem of insufficient adsorption capacity of a single filter media for specific impurities.
The gradient distribution of the filter media can also optimize the flow path of the fluid. The wide channel formed by the large-particle filter media in the upper layer allows the fluid to pass quickly, reducing the initial resistance; the medium-particle filter media in the middle layer slows down the flow rate, allowing impurities to have sufficient time to be intercepted; the small-particle filter media in the lower layer further reduces the flow rate, allowing tiny impurities to be fully captured during the retention process. This gradient change in flow rate allows the fluid to form the best contact state with the filter media at different filtration stages, improving the comprehensiveness of impurity interception.
In addition, the gradation ratio of the filter media has been accurately calculated to ensure a natural transition between the layers and avoid the mixing of filter media. The particle size of the upper filter media is larger than that of the lower layer, and the density is lower than that of the lower layer. This design allows the filter media to automatically restore the gradient structure after backwashing, maintaining the stability of the filtration function of each layer. When the filter layer maintains a clear gradient boundary, the interception effect of each material can continue to play a role, and the filtration efficiency will not decrease due to structural disorder.
The synergistic effect of multi-media filter multi-layer filter materials is also reflected in the adaptability to complex water quality. The impurity composition of fluids from different sources varies greatly, and a single filter material is difficult to cope with all types of impurities. The combination of multiple materials with gradient design can cover all types of impurities from large to small, from organic to inorganic. No matter how the impurity composition in the fluid changes, it can achieve efficient interception through the synergistic effect of each layer of filter material, thereby improving the impurity interception efficiency as a whole and ensuring stable and reliable filtration effect.
