1. Asymmetric fiber filter structure
The core technology of the high-efficiency automatic gradient density fiber filter adopts asymmetric fiber bundle material as the filter material, one end of which is a loose fiber tow, and the other end of the fiber tow is fixed in a solid body with a large specific gravity. When filtering, the specific gravity is large. The solid core plays a role in the compaction of the fiber tow. At the same time, due to the small size of the core, the uniformity of the void fraction distribution of the filter section is not greatly affected, thereby improving the fouling capacity of the filter bed. The filter bed has the advantages of high porosity, small specific surface area, high filtration rate, large interception amount and high filtration precision. When the suspended liquid in the water passes through the surface of the fiber filter, it is suspended under van der Waals gravitation and electrolysis. The adhesion of solid and fiber bundles is much greater than the adhesion to quartz sand, which is beneficial to increase the filtration speed and filtration precision.
During backwashing, due to the difference in specific gravity between the core and the filament, the tail fibers disperse and oscillate with the backwash water flow, resulting in strong drag force; the collision between the filter materials also exacerbates the fiber's exposure in the water. The mechanical force, the irregular shape of the filter material causes the filter material to rotate under the action of the backwash water flow and the air flow, and strengthens the mechanical shear force of the filter material during the backwashing. The combination of the above several forces results in adhesion to the fiber. The solid particles on the surface are easily detached, thereby improving the cleaning degree of the filter material, so that the asymmetric fiber filter material has the backwash function of the particulate filter material.
2. The continuous gradient density filter bed structure
The filter bed composed of the asymmetric fiber bundle filter material exerts resistance when the water flows through the filter layer under the compaction of the water flow. From top to bottom, the head loss is gradually reduced, the water flow speed is faster and faster, and the filter material is compacted. Increasingly high, the porosity is getting smaller and smaller, so that a continuous gradient density filter layer is automatically formed along the water flow direction to form an inverted pyramid structure. The structure is very favorable for the effective separation of suspended solids in water, that is, the particles desorbed on the filter bed are easily trapped and trapped in the filter bed of the lower narrow channel, achieving uniformity of high filtration speed and high precision filtration, and improving the filter. The amount of interception is extended to extend the filtration cycle.
