How To Clean IQF Evaporator Coil

IQF coils face heavy salt mist, protein residue, frost, grease and seafood debris — improper cleaning causes airflow blockage, higher power consumption and shorter coil service life.

1. Pre-Clean Safety & Shutdown Procedure

Stop IQF tunnel/spiral conveyor, cut off refrigeration system power, lock out electrical supply.

Run full defrost cycle to melt all frost/ice on fins; drain all melt water completely.

Isolate refrigeration circuit if deep chemical cleaning is needed; cover fan motors, electrical boxes, control panels with waterproof plastic sheets.

Wear PPE: rubber gloves, safety goggles, waterproof apron, non-slip boots (seafood wastewater is slippery & corrosive).

2. Dry Pre-Cleaning (Remove Solid Debris First)

Use soft plastic bristle brush (no metal wire brush — scratches coating/SS fins, accelerates corrosion) to sweep shrimp shells, fish scales, food particles between fins.

Blow loose debris out with low-pressure dry compressed air (≤3 bar), blow air parallel to fin spacing to avoid bending thin fins.

Vacuum bottom drip tray and drain pan to clear sludge, seafood sediment.

3. Chemical Washing (Critical for Salt & Protein Stains, Seafood IQF)

Recommended Cleaners

Mild alkaline food-grade cleaner: dissolve protein, grease, organic seafood residue

Mild acid food-grade neutralizer (phosphoric acid based): remove salt limescale, brine deposits (mandatory for shrimp/seafood lines)

Avoid strong hydrochloric acid: etches stainless steel coils and damages hydrophilic coating on aluminum fins

Washing Steps

Dilute cleaner per supplier ratio, fill low-pressure sprayer (pressure ≤4 bar, wide fan nozzle).

Spray coil evenly from air outlet side toward inlet side, fully soak all fins and tubes.

Let chemical dwell 5–10 minutes to dissolve salt and protein buildup; do not let cleaner dry on coil surface.

Rinse thoroughly with clean cold water, ensure no chemical residue left in fin gaps and drain pan.

For heavy salt corrosion stains: apply diluted food-grade acid neutralizer, dwell 3 mins, then full water rinse again.

4. Post-Wash Disinfection (Food Processing Standard)

Spray food-safe sanitizer (peroxide or quaternary ammonium) over entire coil, drip tray and drain lines.

Leave to air dry naturally; do not power blow high-speed air immediately.

5. Inspection & Recovery

Check all fins: straighten bent fins with fin comb if airflow channels are blocked.

Clear drain lines to prevent standing water (standing salt water causes tube corrosion).

Remove plastic protective covers from electrical components, wipe dry all fan motors and wiring.

Leave IQF door open for natural air drying for 30–60 mins to eliminate residual moisture before restarting.

Restore power, start system, monitor airflow, temperature and frost forming uniformity.

Key Maintenance Tips for Shrimp IQF Coils

Cleaning frequency

Daily: Quick dry air blow to remove surface shrimp debris

Weekly: Light foam wash + rinse

Monthly: Full chemical clean + salt neutralization + disinfection

For SS316L coils: Acid neutralizer every cleaning to prevent salt pitting

For aluminum hydrophilic coated fins: No harsh acid, only mild alkaline cleaner

Never use high-pressure water jet directly onto coil — bends fins and washes coating away

Always clean drip tray and drain pipe together; sludge buildup breeds bacteria and blocks defrost drainage

Consequences of Poor Coil Cleaning

Fin gap blockage, frequent defrost cycles, 20%–40% higher energy consumption

Uneven freezing, poor IQF product separation

Salt residue accelerates tube/fin corrosion, shortens coil service life

Cross-contamination risk for seafood products