Plate heat exchangers operate with very high heat-transfer efficiency, but their narrow flow channels make them sensitive to fouling. Without regular maintenance, even a small amount of scaling, sludge, biofilm, or oil residue can drastically reduce performance, increase pressure drop, and shorten gasket life.
| Indicator | Typical Sign |
|---|---|
| Heat duty drops by 10–15% | Lower outlet temperature difference |
| Pressure drop increases by 20–30% | Pump power rises |
| Higher energy consumption | Chiller or boiler runs longer |
| Uneven outlet temperatures | Temperature instability |
| Visible leakage or gasket hardening | Drips, stains, or cracks |
| Abnormal vibration or noise | Flow restriction or fouling |
Typical Cleaning Intervals
| Application | Recommended Interval |
|---|---|
| HVAC chilled water | Every 6–12 months |
| Industrial process water | Every 3–6 months |
| Food & beverage | Every 1–3 months |
| Oil, resin, slurry service | As required |
CIP is recommended for light to moderate fouling where disassembly is not required.
Procedure:
Isolate the heat exchanger from the system.
Connect a CIP pump and tank.
Circulate the cleaning solution through the exchanger.
Rinse with clean water until pH is neutral.
Typical Cleaning Chemicals:
Mineral scale: citric or phosphoric acid
Oil & grease: alkaline detergent
Biological fouling: disinfectant solution
Required when fouling is severe or gaskets must be replaced.
Steps:
Mark plate order and orientation.
Loosen tightening bolts evenly.
Remove plates and gaskets.
Clean with warm water and a soft brush (no metal tools).
Inspect for corrosion, cracks, or deformation.
Reassemble and tighten to the original frame dimension.
| Do | Don’t |
|---|---|
| Store in a cool, dry place | Avoid direct sunlight |
| Use compatible cleaning chemicals | Avoid strong solvents |
| Replace hardened or damaged gaskets | Do not overstretch gaskets |
Install strainers or filters upstream
Maintain proper flow velocity
Avoid thermal shock
Monitor pressure drop and temperatures
Apply suitable water treatment
Regular maintenance and proper cleaning extend the service life of plate heat exchangers, minimize downtime, and ensure stable, efficient operation.
