The precision filter is equipped with wound honeycomb filter elements or melt-blown filter elements. It is applied for filtration of production water for drinking water, domestic water, electronics, printing and dyeing, textile, environmental protection and other industries, as well as alcohol filtration, pharmaceutical filtration, acid and alkali liquid filtration, and pre-safety filtration before reverse osmosis RO membranes. It features large flow capacity and low consumable cost. The housing surface is polished or matte finished, and the inner surface undergoes pickling and passivation treatment. Automatic control valves and controllers are equipped for inlet, outlet and drain pipelines to enable automatic backwashing.
1. Working Principle of Precision Filtration
The medium to be filtered enters the cylinder from the side and passes through filter elements for filtration. Liquid flows out from the bottom to remove tiny suspended solids, bacteria and other impurities in the water. Filter residues are discharged by compressed air back-blowing or gas-liquid mixed back-blowing.
2. Characteristics of Precision Filters
2.1 Material and Structure
Cylindrical housing made of 304 or 316L stainless steel; carbon steel and resin housing are optional. It can be fitted with one or multiple filter elements.
2.2 Specifications
Number of filter elements: single or multiple elements
Filter element length: single section, 2 sections, 3 sections, 4 sections (10 inches per section)
Filter element installation types: internationally common flat pressure type, clamp-in type and insert type
Connection mode between cylinder and base: quick-opening type, flange type
Connection mode of medium inlet and outlet: quick-opening type, threaded type, flange type
Filterable media: liquid, gas
2.3 Performance Features
(1) High filtration precision with uniform pore size of filter elements;
(2) Low filtration resistance, large flow rate, strong dirt holding capacity and long service life;
(3) High cleanliness of filter material without contamination to filtered media;
(4) Resistant to acid, alkali and other chemical solvents;
(5) High mechanical strength and heat resistance; the filter element is not easy to deform;
(6) Low cost, low operating expense, easy cleaning and replaceable filter elements.
3. Functions of Precision Filters
Precision filters are usually installed after pressure filters to remove fine particles in liquid and meet the feed water requirements of subsequent processes. Sometimes they are installed at the terminal of the whole water treatment system to prevent fine particles from mixing into finished water.
Common filter element specifications: 0.1, 0.2, 0.5, 0.8, 1, 2, 3, 5, 10, 20, 30, 50, 75, 100, 120 μm.
Precision filters are widely used as safety filters for electrodialysis, ion exchange, reverse osmosis, ultrafiltration and other equipment.