Plate Heat Exchanger Cleaning Chemicals: A CIP Selection Guide

Clean-in-place (CIP) restores heat transfer and pressure drop without opening the plate pack, but only when the chemistry matches the deposit and the plate material. The wrong agent at the wrong concentration either fails to remove the fouling or attacks the plates and gaskets — turning a routine clean into a costly failure. Always start by identifying the deposit type (mineral scale, organic/biological, oil/grease or process-specific) before selecting a chemical.

Acidic agents dissolve inorganic deposits — calcium carbonate scale, metal oxides, rust and other mineral fouling typical of cooling water and hard-water duties. Common choices are nitric acid (1–2%), citric acid (1–2%) and phosphoric or sulphamic acid formulations. Citric acid is the gentlest, widely used food-grade option; nitric acid is more aggressive and effective on heavy scale. Typical CIP runs at 1–2% concentration, 50–65 °C, circulated for 30–60 minutes. Never use hydrochloric acid on stainless steel plates — chlorides cause pitting and stress corrosion cracking.

Alkaline agents remove organic matter, biofilm, proteins, fats and oils — the dominant fouling in food, dairy, brewery and many process duties. Caustic soda (sodium hydroxide, 1–2%) is the standard, often combined with surfactants and sequestrants in formulated cleaners. Run at 1–2%, 65–80 °C for 30–60 minutes. In hygienic plants, a two-stage CIP is common: an alkaline cycle to remove organics, followed by an acid cycle to remove mineral scale, with a thorough water rinse between and after each stage.

Stainless steel (304, 316L) tolerates most nitric, citric and caustic CIP chemistries, but is vulnerable to chlorides — never clean stainless plates with hydrochloric acid or chloride-bearing agents, and limit free chlorine in any biocide. Titanium plates are far more forgiving of chlorides and most acids, but are attacked by hydrofluoric acid and by hot, concentrated reducing acids — avoid HF-based descalers entirely. For both materials, keep acid concentration and temperature within the chemical supplier's limits and confirm gasket compatibility (EPDM, NBR, FKM) before circulating.

Cleaning effectiveness depends on the balance of concentration, temperature, flow turbulence and contact time. Higher temperature and concentration speed up cleaning but increase the risk of attacking plates and gaskets. As a rule, use the lowest concentration and temperature that clears the deposit in a reasonable contact time, maintain turbulent flow (forward and reverse if possible) to lift loosened material, and always rinse to neutral pH before returning to service. Verify success by checking that pressure drop and heat transfer have returned toward the clean baseline.

CIP chemicals are corrosive — use appropriate PPE, dose into water (never water into acid), and follow the supplier's safety data sheet. After each cycle, rinse thoroughly with clean water until the effluent is pH-neutral; residual acid or caustic accelerates gasket ageing and can contaminate product. Neutralise and dispose of spent solutions according to local environmental regulations.

If you are unsure which chemistry suits your deposit and plate material, send your fouling type, plate material, gasket compound and operating conditions to Evan at jxmike@shheatex.com or WhatsApp +86 173 1725 8304. Our engineering team will recommend a safe CIP procedure and supply compatible replacement plates and gaskets when needed.