Regeneration filters for water-treatment and condensate-treatment facilities (FUZH)

Regeneration filters for water-treatment and condensate-treatment facilities (FUZH)

Purpose. Iron removal filters are designed to purify water from iron (Fe2+), poorly soluble iron (Fe3+), manganese and hydrogen sulfide ions.

Manganese-enriched rocks; crushed gaize, artificial aluminosilicate filtering materials, developed hydroantracite, non-activated copolymer of styrene with divinylbenzene are used as filtering medium in iron removal filters.

Design description. Iron removal filters FUZH are structurally similar to the FSU filters and are designed for the use of a wide range of sorption, sorption-catalytic filter materials. FUZH filters consist of:

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

FUZH filter housing 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).

Upper collection-distribution device of the "dished overflow" type and lower collection-distribution device of the "false bottom" type with stainless slot caps FEL are most often used for FUZH filters.

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

• adsorption and catalytic oxidation (filtration);
• backwashing;
• blowback;
• regeneration (restoration) of the filtering media (deferrization catalyst);
• discharge of the primary filtrate.

The incoming flow under pressure enters the hydrodynamic mixer (SGD), where it is mixed with the flow of the oxidizer and sent further to the upper collection-distribution device of the FUZH filter; the flow is evenly distributed and passes through the layer of filtering medium downwards. The removing poorly soluble impurities are adsorbed by the particles of the filtering media and films of the sparingly soluble iron hydroxide (Fe3+) with further oxidation of iron (III), manganese and hydrogen sulfide ions. The filtrate is discharged from the filter through the lower collection-distribution device to the collector.

On the filter medium, the adsorbed contaminations are subjected to full oxidation and aggregation of the films (flakes). The accumulated excess air during the oxidation of the incoming flow is removed through an automatic relief valve located on the aeration column or at the top of the FUZH filter.

These filters allow restoring the sorption activity of the adsorbent-catalyst or other special filtering media by blowback with clean water or treatment with special solutions.

At the end of the cycle, the FUZH filter is stopped, disconnected from the main pipes, and the flow of purified water comes upwards for blowback. Wash water is discharged into the drainage. To increase the efficiency of the blowback process and accelerate the regeneration of catalytic activity, the filter media is backwashed upwards with compressed air. Some filter media regeneration technologies use regenerative solutions.

At the end of washing and regeneration of filtering medium activity, the filter is switched on or remains in standby mode. Right after the filter is switched on, the first portion of the filtrate is discharged into the drainage.

In addition, efficient operation of these filters require auxiliary equipment for pre-processing of the incoming flow with one of the oxidants (dissolved air oxygen, ozone, sodium hypochlorite (NaClO), potassium permanganate (KMnO4)). Such auxiliary equipment is the SGD (hydrodynamic mixer), and for technologies that use air oxygen as an oxidizer it is an air compressor, and in the absence of hydrodynamic mixer it is an aeration column (KA).

The operation cycle ends when one of the specified parameters is reached: an increase of the pressure difference between the inlet and outlet of the filter (determined by the pressure gauge) or a certain amount of filtrate of the required quality is obtained.

The operation cycle of the FUZH filter ends when the concentration of one of the specified parameters of filtrate (iron, manganese, hydrogen sulfide) is exceeded and/or when the pressure difference between the inlet and outlet exceeds 0.3 MPa.

Specifications. Material of FUZH 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 FUZH filters varies from 1000 to 3000 mm, capacity of the devices: from 11 to 93 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 iron removal filters (FUZH)

Iron removal filters (FUZH) 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.