Mechanical filtration sewage treatment the most commonly used method, according to the filter medium is different, mechanical filtration equipment is divided into two categories, granular media filter and fibre, particle filter medium mainly sand as filter medium, the particle filter, such as by particles and sand filter material adsorption between pore solid in the water interception function realization of filtering, the advantage is easy to recoil, the disadvantage is that the filter speed is slow, generally no more than 7 m/h; The core filter layer has only the surface of the filter layer. The filtration accuracy is low, only 20-40 meters, which is not suitable for fast filtration of sewage with high turbidity.
Efficient asymmetric fiber filter system USES asymmetric fiber bundle as the filter material, the filter material for asymmetric fiber, on the basis of fiber bundle filter material, added a nuclear, make its have the advantages of fiber filter material and particle filter material, due to the filter material of special structure, the pore porosity of filter bed soon formed under the big small gradient density, filter speed fast, large amount of sewage and backwash, through the special design, make the dosing, mixing, flocculation and filtration process within a reactor, the device can effectively remove suspended organic matter in aquaculture water, reduce water COD, ammonia nitrogen, nitrite, etc., It is especially suitable for the filtration of suspended solids in the circulating water of the temporary tank.
1. Asymmetric fiber filter material structure
Efficient automatic gradient density fiber filter core technology is to use asymmetric fiber bundle as the filter material, its end is loose fibre bundle, the other end of the fibre bundle is fixed in the proportion of large solid body, filtering, the proportion of large solid nuclear have played an important role of the fibre bundle of pressure, at the same time, due to the small size of nuclear, the filter section has a little influence on the uniformity of the void fraction distribution, so as to improve the carrying capacity of the filter bed. Make the filter bed fiber filter of high porosity, specific surface area of small, high speed, large amount of sewage and filtration precision higher advantages, when suspended solids in water flows through the fiber filter material surface, in the role of van der Waals force and the electricity, suspended solid and adhesion strength of the bundle is greater than and adhesion of quartz sand, to improve speed and filtration precision.
During backwash, due to the difference in specific gravity between the core and the filaments, the fibers of comet tail spread out and wobbled along with the backwash flow, generating a strong drag force. Collisions between liao also contributed to the fiber in water by mechanical force, irregular shape makes the filter material filter material under the effect of backwash water and air to produce rotation, to strengthen the back flush filter material by mechanical shearing force, the combination of the above several kinds of force results attached to the solid particles on the surface of the fiber is easy to fall off, so as to improve the filter material XiJingDu, such asymmetric fiber filter material and the back flush function of particle filter material.
2. Continuous gradient density filter bed structure with upper and lower density
Asymmetry of fiber bundle filter, filter bed under the compaction of the water flow, water flow through filter layer resistance, from top to bottom, head loss reduced gradually, the flow speed is faster and faster, filter material compaction degree is more and more high, porosity is more and more small, so along the flow direction, automatic filter layer form a continuous gradient density distribution, forming an inverted pyramid structure. The structure is very conducive to the effective separation of suspended solids in water, that is, the particles desorbed from the upper part of the filter bed are easy to be captured and trapped in the filter bed with a narrow channel at the lower part of the filter bed, so as to realize the unification of high filtration rate and high precision filtration, increase the amount of filterinterception and extend the filtration cycle.
