A food-additive producer rated for 10,000 metric tons/yr was losing throughput to deposition across multiple heat exchangers. The incumbent supplier identified the deposit as calcium phosphate and lowered orthophosphate while raising dispersant — with no effect — and the account was at risk. An independent, first-principles investigation found the true mechanism, corrected the program with no capital, and restored 100% of production.
Deposition across multiple heat exchangers was cutting throughput and putting the plant at risk of an unplanned shutdown, with repeated online and offline exchanger cleanings adding cost and downtime.
The incumbent water treatment supplier had pulled a deposit sample, identified it as calcium phosphate, and done the textbook thing — reduced the orthophosphate residual and raised the polymer dispersant. The deposition continued unchanged.
With the standard phosphate playbook exhausted and no improvement, the relationship was deteriorating and the account was at risk of being lost.
Reconciled the actual chemical feed against the actives that should exist in the system — predicting residuals from feed rates rather than trusting setpoints and wet-test numbers alone.
Audited setpoints, reporting, and control logic with onsite personnel interviews; profiled and borescoped the worst exchangers to recreate the deposition history.
Applied a competing-salt saturation model resolving up to 100 salts to identify what could actually precipitate under the hottest exchanger conditions — then redesigned the program with a polymeric/phosphonate synergy and a stronger terpolymer dispersant. No capital required.
Orthophosphate was in control and HEDP read fine by wet test — but far more HEDP was being fed than the residual showed. Iron and manganese in the system consumed part of it.
In the hottest exchangers, the overfed HEDP overwhelmed the system and formed a direct calcium–HEDP salt. On a routine deposit analysis, calcium–HEDP reports as calcium phosphate — which is exactly why every phosphate-based correction failed. The polymer was also overfed to ~175% of target, enough to foam. Rebalancing to a polymeric/phosphonate synergy with a stronger terpolymer dispersant eliminated the deposition entirely.
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Independent root-cause analysis for food & beverage, industrial and institutional cooling water programs. No chemistry sold. Competing-salt saturation modeling included.