Multi-media filter

Ⅰ. Overview

    Filtration of the meaning, in the water treatment process, the filter is generally refers to the quartz sand, anthracite and other filter layer cut off suspended solids in the water, so that the water to obtain a clear process. The porous material used for filtration is called the filter material, and the quartz sand is the most common filter material. The filter is granular, powdery and fibrous. Commonly used filters are quartz sand, anthracite, activated carbon, magnetite, garnet, porous ceramics, plastic ball and so on. The same time as

Multi-media filter, using two or more media as a filter layer of the media filter, in the industrial circulating water treatment system, to remove impurities in the sewage, adsorption of oil, so that water quality in line with the requirements of recycling.

Ⅱ.Applicable scope

    Multi-media filter is mainly used for water treatment in addition to turbidity, softened water, pure water pre-treatment, water turbidity up to 3 degrees below.

    The role of filtration, mainly to remove the suspended or colloidal impurities in the water, in particular, can effectively remove the precipitation technology can not remove the small particles and bacteria, BOD5 and COD also have some degree of removal effect.

    1. Pretreatment of reverse osmosis, electrodialysis, ion exchange, ultrafiltration and other systems

    2. Power generation, chemical, paper, beverage and other raw water pre-filtration treatment

    3. Chemical plant water decolorization, to organic matter

    4. Domestic water pretreatment

    5. Industrial water treatment

    6. Swimming pool water treatment

    7. Circulating water bypass system

    8. Surface water, groundwater drop in addition to color

    9. Wastewater treatment

Ⅲ.Features

    1, porous media filter is widely used in water treatment process, can be used alone, but most of the water quality as the depth of treatment (exchange resin, electrodialysis, reverse osmosis) pre-filtration. The same time as

    2, multi-media filter is commonly used in the depth of water purification pretreatment device, according to process requirements to fill a different filter. The same time as

    3, multi-media filter material can be used glass steel, A3 steel corrosion or rubber, all stainless steel. Operation mode is automatic and manual two forms, automatic control is the use of US imports of automatic controller and gas, hydraulic valve control, easy to operate and easy maintenance, in all walks of life water treatment process pre-processing device has been widely used The The same time as

    4, multi-media filter (including double filter filter) filter material should have sufficient chemical stability, the relative density of media and particle size should be a certain difference, composed of anthracite and quartz sand composed of double filter The relative density of the anthracite used in the furnace is 1.4-1.6, the particle size is 0.8-1.8mm, the relative density of the quartz sand is 2.6-2.65, the particle size is 0.5-1.2mm; the 3-layer filter filter is besides the above two kinds of filter media Can be used manganese sand, magnetite and the like heavy ore, the relative density of 4.7-5.0, particle size of 0.5-4mm.

Ⅳ.Technical Parameters

    (1) expansion height: backwashing, in order to ensure that the filter particles have enough gap so that the dirt quickly with the water discharge filter layer, filter layer expansion rate should be larger. However, when the expansion rate is too large, the number of particles in the unit volume is reduced, and the chance of particle collision is reduced. Double layer filter, the expansion rate of 40% ---- 50%.

Note: In the production run, the filter height of the filling, expansion height and other random inspection, because the normal backwash process, there will be part of the filter material lost or wear, need to be added. Relatively stable filter layer, has the following advantages: to ensure the stability of the filter water quality, to ensure the effect of backwashing.

    (2) backwash water and pressure: the general design requirements, anti-washing water intensity of 40 m3 / (m2 · h), backwash water pressure ≤ 0.15 MPa. The same time as

    (3) backwashing air volume and pressure: backwash air strength of 15 m / (m · h), backwash air pressure ≤ 0.15 MPa. The same time as

NOTE: During the backwash process, the incoming backwashing air is collected at the top of the filter and most of it should be discharged through a two-hole vent valve. Daily production. Always check the exhaust valve patency, the main characterization of the ball in the degree of freedom.

Ⅴ.Air and water union

    (1) first rinse with air, then water backwash: first filter water level down to 100 mm on the surface of the filter layer, into the air for several minutes, and then backwash with water. Applicable to the surface pollution and internal pollution of the light filter.

Note: the corresponding valve, closed must be in place; otherwise, the water level below the surface of the filter layer, the upper part of the filter layer without water infiltration, particles up and down the process of disturbance, dirt can not be effectively discharged, but will filter deep mobile.

    (2) air and water combined backwash: from the bottom of the static filter at the same time into the air and backwash water, the air in the process of rising in the sand layer to form a large bubble, when the filter into a small bubble, The scrubbing effect on the surface of the filter material; backwashing the top of the loose layer, so that the filter was suspended, conducive to the air on the filter scrub. The swell effect of backwash and backwashing air is superimposed on each other, and is stronger than when it is single. The same time as

Note: water backwash pressure and air backwash pressure and strength are different, should pay attention to the order, to avoid backwash into the air pipe.

    (3) after the end of the air-water combined backwash, stop into the air, backwash water to maintain the same flow, continue to rinse 3 min ~ 5 min, you can remove the bubbles left in the filter bed.

Note: Pay attention to the status of the top double-hole vent valve.