The ion-exchange method of water and condensate treatment is implemented in the following ion-exchange bed filters:

• FIPa I: primary ion-exchange parallel-flow filters;
• FIPa II: secondary ion-exchange parallel-flow filters;
• FIPr: ion-exchange counter-flow; 
• FIPr-2P: ion-exchange double-flow - counter-flow filters;
• FISDNr: ion-exchange mixed-bed filters with external regeneration;
• FISDVr: ion-exchange mixed-bed filters with internal regeneration;
• FR: regeneration filters for ion-exchange mixed-bed filters with external regeneration (FISDNr).

The first digit in the filters' typical size description that comes after the letter symbols, denotes the filter's diameter in m (1.0; 1.4; 2.0; 2.6; 3.0; 3.4), and the second one denotes the nominal pressure in MPa (0.6 or 1.0) Certain intended use of the filter is determined by the type of ion-exchange resin filled in the filter. The differences in primary and secondary filters are related to the calculated filtration rate.

The filter consists of a cylindrical vessel with upper and lower elliptic bottoms, upper and lower drainage distribution assemblies, piping lines equipped with valves, and instrumentation located outside the filter. The lower distribution assembly intended for retention of the ion-exchange resin, discharge of the permeate, and distribution of water for loosening, is mounted on the concrete pad or placed as the "duplicated bottom." (Colour layout schemes on the concrete pad and the false bottom in section are taken from the web-site).

The upper distribution assembly is intended for uniform distribution of incoming water and regeneration solution through out the ion-exchange resin layer and for discharge of water for loosening. System of pipe lines and valves connected to the filter ensures execution of all process steps required during the filter operation. Lower distribution assemblies are based on:

   а) slotted caps produced by "TEKO-FILTER" company;

   б) slotted drainage units of groove-type.

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* The text is taken from:
A.S. Kopylov, V.M. Lavygin, V.F. Ochkov, "Water-treatment in power energetics"
(M. MEI Publishing House, 2003).

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