Activated Sorption Carbon Filter Tank for Water Pretreatment (FSU)

Activated Sorption Carbon Filter Tank for Water Pretreatment (FSU)

Purpose. Activated Sorption Carbon Filter Tank (FSU) are widely used as "scavengers" (organic substance absorbers) in units for primarily desalting water to protect ionites from fouling in ion-exchange filters; as the first or second treatment stage of industrial sites sewage and hydraulic structures sewage; as the last afterpurification stage of industrial effluents before discharge into fish-farm basins; as a stage of drinking water afterpurification (to improve organoleptic factors), etc.

Activated carbon based on black coal and wood coal, charred coal and special sorbents (MIU-S, zeolite, aluminosilicates) are used as the filtering media in sorption carbon filters.

Design description. Industrial sorption carbon filters FSU consist of:

• housing;
• upper and lower distribution devices;
• piping;
• stop valves;
• sampling devices.

The housing of the FSU filter is cylindrical, welded of sheet steel, with welded elliptical stamped bottoms. Three supports are welded to the bottom for mounting the filter on the foundation.

Upper and lower bottoms have flanges welded in the center, to which outside along the filter front – pipes are to be connected, and inside – collection-distribution devices (NRU and VRU).

In standard package sorption carbon filters have the upper collection-distribution device of the “radial” type with perforated pipes or of the "dished overflow" type. A "duplicating" type or a "false bottom" type system is used as a lower drainage device.

Operation principle. The filter cycle consists of the following stages:

• sorption and adsorption (filtration);
• preventive backwashing with blowback;
• discharge of the primary filtrate (fine coal dust suspension);
• complete or partial replacement of the filtering medium.

The incoming flow under pressure enters the filter, is evenly distributed by the upper collection-distribution device and passes downwards through the layer of filtering medium. The removed impurities are sorbed (absorbed) by the developed inner surface of the filter media particles, and the filtrate is discharged from the filter to the collector through the lower collection-distribution device. For high-quality cleaning of steam condensate from oil products, the temperature of the incoming flow is important (it must be at least 70°C, the optimal value is 90°C).

During the filtration process the preventive backwashing and blowback of the filter media is performed regularly (1-2 times a week) to prevent packing and to remove organic films. It is done very carefully to avoid the removal of the upper layers of the filtering medium.

Since the technology of restoring the sorption activity (capacity) of the sorbent is labour-intensive and energy-intensive, filtering materials of this group are used in most technological schemes only once and further replaced with a new one. Waste filter materials are disposed according to the established procedure.

The operation cycle of the FSU filter ends when one of the specified parameters of filtrate is exceeded and/or when the ∆P between the inlet and outlet ≥0.3 MPa.

Pressurized incoming water is supplied to the filter, uniformly spreads by the top collection and distribution assembly and passes through the filtering bed downwards. All removed impurities are sorbed by the enlarged inner surface of the filtering material's particles, while the permeate water is removed through the lower drainage assembly into the collecting receiver. The incoming flow temperature is essential for high-quality purification of steam condensate from oil products (the temperature shall be at least 70°С, 90°С is optimal).

To prevent packing and remove organic films, a regular (1-2 times a week) loosening and backwash of the filter's bed shall be performed with a great care to avoid removal of filter bed's upper particles.

Since regeneration of the sorption activity (capacity) of the sorbent agent is a labour- and energy-intensive process, filtering materials of this group are used only once in the majority of process flow charts, with further replacement and disposal of the waste filtering materials according to the established procedure.

The operation cycle of FSU filter is over when one of the specified parameter of permeate quality is not achieved and/or inlet-outlet pressure differential is more than 0.3 Mpa.

Specifications. Material of FSU filter housing: stainless steel, carbon steel, low-alloy steel, plastic (polyamide 6, reinforced polyester).

Material of internal devices: stainless steel 12H18N10T, 03H17N14M3 or 10H17N13M2T, PVC, CPVC, polypropylene, PVDF, titanium.

Diameter of the housing of the manufactured FSU filters varies from 400 to 3400 mm, capacity of the devices: from 1 to 60 m³ / h, working pressure: 0.6 MPa, 1.0 MPa and higher.

Protective coatings. A special anti-corrosion coating is applied to the filters’ inner surface, which contacts the working medium. The type and brand of coating is selected depending on the characteristics of the aggressive environment (epoxy, polyurethane, gumming with rubber, preserving primer, etc.). At the request of the customer, any coating available on the market can be applied.

The outer surface of the filters is coated with standard priming enamel. At the customer’s request, the outer surface can be painted in corporate colors and with the use of special protection against corrosion (ROSNEFT, SIBUR, GAZPROM, LUKOIL, etc.).

Product line and specifications of activated sorption carbon filter tank (FSU)

Sorption carbon filters (FSU) have a number of advantages:

• High mechanical strength. All filter models undergo strength calculation, the results of which are attached to the certificate.
• Long-term trouble-free operation. The internal design of the filters is unique development of our company. They have been effectively used at many sites for more than 25 years.
• Production by individual order or technical specification of the Customer. Any packaging arrangement and design of filters according to customer requirements is possible.
• Quality assurance from the manufacturer. All technologies, equipment and personnel at the enterprise are certified in accordance with the requirements of regulatory documents of the Russian Federation. All materials undergo incoming inspection and testing.