scope:

OBJECT AND SCOPE

This Code defines the procedures for the accurate testing of ion exchange equipment for the purpose of determining level of performance.

This Code includes the following types of ion exchange equipment, which are either used individually or in various combinations depending on process requirements.

Softener - Ion exchange equipment containing cation exchange resin used for the removal of hardness ions (calcium and magnesium), exchanging them for sodium ions.

Dealkalizer - The application of ion exchange equipment containing ion exchange resin to reduce alkalinity in waters. For example, anion resin in the chloride form may be utilized, exchanging bicarbonate, carbonate, nitrate and sulfate ions for chloride ions in this process.

Multi-Bed Systems - The combination of cation and anion exchangers, usually in series flow and sometimes in combination with mixed-bed exchangers, for the purpose of treating and processing water and/or dilute aqueous solutions.

Mixed-Bed Unit - The use of intimately mixed hydrogen-form cation resins and hydroxide-form anion resins in a single ion exchange vessel; this type of equipment usually provides the highest quality treated water.

Stratified-Bed Unit - The application of layers of weak-acid and strong-acid cation exchange resins, or weak-base and strong-base anion exchange resins in ion exchange vessels. This application is typically made to improve treatment efficiency.

Condensate Demineralizer - Ion exchange units applied to the removal of contaminants from steam condensates. Mixed-bed units are utilized for this application at much higher flow rates per square foot of resin bed surface than mixed-bed units employed for high solids water processing.

Condensate Sodium Ion-Exchanger - Ion exchange equipment containing cation exchange resin in the sodium form which is used for the removal of contaminants from steam condensates. Generally, this equipment is designed to operate at a much higher flow rate per square foot of resin bed surface than a typical softening ion-exchanger. Mixtures/blends of steam/process condensate and makeup water may also be processed by this equipment.

Organic-Trap - The application of selected ion exchange resins to remove large organic molecules from waters to be treated. This selection can be made in lieu of gravity separation and flocculation equipment, such as conventional clarifiers, to remove organics.

Mixed-Resin Unit (Special Ionic Form) - The use of intimately mixed cation and anion exchange resins in forms other than hydrogen and hydroxide. Such units are used in some applications for treatment of contaminated steam condensate. Other applications find use in treatment of nuclear primary coolant and nuclear waste management flows, performing soluble radionuclide removal as well as filtering capability for particulate removal.

This test Code applies to ion exchange equipment and systems that are utilized for:

(a) The conditioning of makeup, feedwater and/or steam condensate in a conventional fossil fuel cycle.

(b) The conditioning of makeup, feedwater and/or steam condensate in a nuclear cycle, primary coolant purification, core-bypass purification and use in waste management systems.

(c) The conditioning of process waters.

Ion exchange systems will typically consist of all equipment, including service, regeneration and resin storage vessels; and includes all piping, pumps, valves, controls, instrumentation and ion exchange resins.

Ion exchange systems are normally designed to regenerate ion exchange resin in either of two modes:

(a) In-place resin regeneration which is performed in the service vessel.

(b) External regeneration which is accomplished in specifically designed regeneration vessels which are part of the particular ion exchange system.

Ion exchange resins are normally regenerated with acids, alkalies, salts, or combinations of these materials to convert them to the exchange form desired. In some cases, such as specific nuclear applications, exchange resins may be supplied in a regenerated form ready for immediate use. These resins are normally disposed of after their service capacity has been utilized.

This Code applies to the performance of ion exchange equipment at design, minimum or maximum flow rates, depending on the purpose of the test, with regard to one or more of the following:

(a) Water quality, influent and effluent

(b) Pressure drop, flow and temperature

(c) Operating ion exchange capacity

(d) Regeneration efficiency

(e) Resin volume and testing

(f) Backwash and rinse properties

(g) Regenerant purity and solution concentrations

(h) Resin transfer equipment