Ion-Exchange Columns (Filters)

A family of equipment whose peculiar feature is use thereof as a filtering layer of ion-exchange resins (IER).

 Function

 The filters are designed for desalination or softening of waters used in various technological processes, among them in thermal and nuclear power generation, in food, chemical, medical and other industries.

 To purge waters from mechanical (solid-phase) impurities, multiple types of bulk filters are designed which are devices with a hydraulically uncharged “pseudo bottom” and an original system of complete hydraulic removal of waste IERs out of the body from the flat bottom – these are filters with “disintegrated” filtering layer, a radial filter, and cylindrical columns.

 Filters with “disintegrated” filtering layer are peculiar with availability of an additional distributing unit which is located in the filtering material layer (for “disintegrating” the latter) at a distance of 0.5 m from its upper level. The purge (regenerating) fluid will loosen the layer of the charge located above and wash out solid impurities from it which were caught earlier by this layer; while the layer lower part is in a stationary state, so the generated sorption front therein will not be disturbed.

 A radial filter will be equipped with an original distributing unit for purged liquid flow. This unit is installed vertically and coaxially to its body. At the periphery, by the wall of the body, elements for collecting the filtered liquid are also installed vertically, i.e. the filtered flow will pass through the IER bulk layer in radial direction, that is, from centre to periphery.

 Technical Characteristics

 Parameter

 

Radial filter

Cylindrical columns

Diameter

 -

0.2 – 3.2 m

Inner diameter

max. 3.0 m

 -

Overall height

max. 8.0 m

1.4 – 8.0 m

Filtering layer height (Hc)

2.5 – 4.0 m

0.7 – 4.0 m

Working pressure

up to 1.6 MPa

0.6 – 9.5 MPa

Maximum allowable pressure drop

0.4 MPa

 -

Volumetric efficiency

appr. 1500 m3/h

 -

Filtering linear rate

 -

10 – 100 m/h

 To perform fine purging of large volumes of liquids (for instance, turbine condensates) which contain small amounts of solid and salty impurities, it is rational to use thin (about 10 mm) filtering layers of fine-dispersed or powdered IERs (to 0.05 - 0.10 mm). This process will be best performed in cartridge filters wherein a filtering layer on cartridges’ surface will be formed by hydraulic in-wash.