Deionizing resin consists of cation and anion resin beads. Resin beads are porous, chemically inert polystyrene beads that are chemically treated. These beads are small, highly porous spheres. The porous structure provides a multitude of sites for ions to become attached during subsequent chemical treatments.
It is only after chemical treatment that a bead becomes anion or cation. In order to make a cation bead, the inert polystyrene bead is subjected to a treatment with an acid such as hydrochloric acid. This acid treatment puts the H+ ions on a multitude of sites on and within the porous sphere. Similarly, in order to make an anion bead, the inert polystyrene bead is subjected to a treatment with a caustic soda which puts the OH ions on a multitude of sites on and within the porous sphere.
There are two ways of deploying these beads:
• Dual bed – The anion and cation beads are kept in separate containers and the water is passed sequentially through the containers.
• Mixed bed – The anion and cation beads are mixed together in one container and the water is passed through the mixture.
Although early Wire EDM dielectric systems employed dual bed resin systems, most current generation machines utilize mixed bed systems.
Since the anion beads have fewer active sites available for ion exchanges, it is necessary to have more anion beads than cation beads in order to have a balanced system with equal ionic capacity. Thus, for a dual bed system, the anion container needs to be larger than the cation container. In a mixed bed system, the mixture needs to have proportionately more anion beads than cation beads. That proportion is typically 60% anion and 40% cation. It should also be noted that the cost to produce anion resin is approximately three times the cost to produce cation resin.
Lanlang supply Deionizing resin for 15 years! Contact us to get the best quote.