Mixed Bed Polisher Silica Breakthrough & Sizing Calculator
Calculate mixed-bed demineralizer polisher service run time to reactive silica breakthrough (<10 ppb), Strong Base Anion (SBA) resin capacity, and chemical regenerant demand.
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Frequently Asked Questions
Why is reactive silica always the first ion to break through a mixed-bed demineralizer?
Strong Base Anion (SBA) resin binds anions in order of chemical selectivity: Sulfate (SO4 2-) > Nitrate (NO3-) > Chloride (Cl-) > Bicarbonate (HCO3-) > Silicate (H3SiO4-). Because silicate is the most weakly ionized species, stronger mineral acid anions displace adsorbed silica, causing a sudden spike in effluent silica concentration while overall electrical conductivity remains ultra-low.
Why is silica strictly limited to < 10 ppb in high-pressure power boilers?
At boiler operating pressures above 1000 psig (70 bar) and temperatures above 500°F (260°C), silica exhibits volatile vapor solubility in high-pressure steam. As steam expands and cools across low-pressure turbine blades, gaseous silica precipitates out as hard, glassy quartz crystals that erode blading, distort aerodynamic profiles, and cause disastrous turbine imbalance trips.
How are the cation and anion resins separated before regeneration?
Because Strong Acid Cation (SAC) resin requires acid (HCl/H2SO4) while Strong Base Anion (SBA) resin requires heated caustic (NaOH), they cannot be regenerated together. During backwash, hydraulic density separation occurs: dense brown SAC resin (SG ~ 1.25) sinks to the bottom, while light amber SBA resin (SG ~ 1.08) floats to the top, allowing split chemical injection through a middle collector lateral.