Fiber filtration technology since the 1980s began industrial application in our country, with the characteristics of high filtration accuracy, fast filtration speed, large pollution intercation capacity, become quartz sand and other granular filter products replacement products, market share has been expanding. In the actual application process, researchers continue to improve, from the fiber ball [1] and comet [2] fiber filter media represented by the “natural packing” and capsule extrusion [3] and movable orifice plate [4] represented by the two directions of the fiber filtration technology development and exploration. Especially in recent years, researchers from the theoretical bold innovation, combined with the technical advantages of two types of fiber filter, starting from the characteristics of the fiber itself, through in-depth theoretical analysis and experimental study, in the selection of the most suitable for the filter material fiber and the best bulking process based on the design of the filter effect is good, and conducive to backwash equipment structure, While solving the technical problems of high precision and difficult cleaning of fiber filter material, the self-feedback operation of fiber filter device is realized. At the same time, the ideal effect of simple equipment structure, convenient operation and basic maintenance-free is achieved. A flexible self-feedback fiber filter technology is formed.
Natural packing staple fiber filter
The so-called “natural accumulation type” fiber filter refers to the bed structure similar to the particle bed, only the fiber filter material instead of the particle filter material. At present, the main natural accumulation type fiber filter are: fiber ball filter, comet type fiber filter.
Fiber ball filter high filtration accuracy, large amount of pollution interception :3 ~ 10kg/m3, long filtration cycle, short circuit, less bias phenomenon. The deficiency of fiber ball filter material is: backwash, the filter element dense mud is difficult to wash off, this part of the residual mud on the one hand to reduce the fiber ball fouling capacity, on the other hand in the filtration again due to the release of pressure filter material and affect the water quality, filter material service life is short, high cost.
Comet fiber filter is named for the appearance of the filter material similar to “comet”, the filter speed can be up to 50m/h, and the backwash performance has been greatly improved. Comet type fiber filter material in the use of the main problems are: backwash using mechanical mixing, easy to destroy the filter material, such as taking large strength gas water wash filter material loss.
Long fiber filter with ordered loading
Orderly loading of long fiber filter material using polypropylene filament as the filter material, the equipment is equipped with a structure limiting the location of the filter material. Due to greatly improve the backwash gas, water on the fiber filter material, so the backwash effect is good. More typical are: capsule extrusion type fiber filter, movable hole plate fiber filter.
Capsule extruded fiber filter is a kind of fiber bundle filter used successfully earlier in Chinese engineering field. It has been widely promoted in the 1990s because of its fast filter speed, thorough backwash and adjustable precision. In the long-term application of this type of filter, the capsule is easy to fatigue and damage, the maintenance amount is large, the operation is complicated, and the capsule filling in the filter layer reduces the effective filtration area of the filter bed.
Movable hole plate fiber filter eliminates capsule, increases the fouling capacity, simple operation, high filtration speed. The main disadvantages of this type of filter are: the sliding orifice plate with check valve and guide post is easy to jam, which affects the stable operation. If the single stainless steel orifice plate is used, because the orifice plate has a certain weight, the water head loss of filtrate flowing through the sliding orifice plate has a small thrust on the slide plate, so the compression effect on the fiber layer is limited; If the upper water filter is used, the displacement amplitude of the movable orifice plate is not enough to fully stretch the fiber bundle when backwashing, so it is difficult to achieve the best cleaning effect.
Theoretical basis, structural characteristics and performance advantages of flexible self-feedback fiber filter
Through theoretical analysis and a large number of experiments, the researchers made bold innovations and developed a unique flexible self-feedback fiber filtration technology.
(1) According to the fiber deep filtration theory, combined with the advantages of “natural stacking type” and “ordered packing type” two types of fiber filtration equipment, flexible self-feedback fiber filter uses polypropylene filament as the filter material, using the upper end of the free structure and unique fiber bundle installation, so that the fiber filter bed is close to the state of short fiber natural stacking bed, Cleaning and show the “orderly filling” state, effectively solve the fiber filter material filtration effect is good and difficult to clean the contradiction, not only to ensure the filtering effect and water quality, but also greatly improve the backwash effect.
(2) the filter material is polypropylene filament, small density, fixed at the bottom, free at the top, fiber density changes with the size of the water pressure difference, the formation of a flexible self-feedback filtration mechanism, high filtration accuracy, and avoid short circuit, bias phenomenon.
(3) Flexible self-feedback fiber filtration technology has high filtration accuracy: the removal rate of suspended matter in water can be close to 100%. When the turbidity of raw water after good coagulation treatment is less than 20FTU, the turbidity of filtered effluent is always less than 2FTU. It can remove impurities such as bacteria, viruses and macromolecular organics. Fast filtration speed: 30m/h-50m/h, 3-5 times of the traditional filter; Intercepting capacity: 5-10Kg/m3 (filter material), is the traditional filter intercepting capacity of 2-4 times; Small footprint: the same amount of water, the footprint is only 1/3-1/2 of the traditional filter; Low self consumption of water: only 1-3% of the periodic water production; In general, raw water can be used for backwashing; The continuous service life of the filter element shall not be less than 10 years, and there shall be no phenomena such as running out of material and hardening.
Flexible self-feedback fiber filtration technology equipment is simple in structure, convenient in operation, and basically maintenance-free. In the equipment self-consumption water rate, operation cost, infrastructure investment and other indicators are in the domestic leading level. The technology can replace the traditional quartz sand filtration in the water supply, circulating water purification treatment, municipal water filtration treatment, sewage advanced treatment and other industrial fields in the electric power, petrochemical industry, and can easily transform the original sand filter, fiber filter technology.
Post time: Feb-02-2023