Coil Materials for IQF Evaporator

Coil Materials for IQF Evaporator

Materials are selected based on corrosion resistance, heat transfer, hygiene, cost, and seafood/food safety. Below are the most common coil tube and fin materials used in IQF freezer Evaporators.

1. Tube Materials (Primary Heat Exchange)

Stainless Steel Tube (SS304 / SS316L)

Highly recommended for seafood/shrimp IQF

Excellent corrosion resistance to saltwater, brine, moisture

Hygienic, easy to clean, food‑safe

Lower thermal conductivity than copper

SS316L preferred for high-salt, harsh conditions

Application: Shrimp, fish, seafood processing IQF

Aluminum Tube

Low cost, lightweight

Moderate heat transfer

Low corrosion resistance

Rarely used in food-grade IQF evaporators

2. Fin Materials

Aluminum Fins

Standard for most IQF evaporators

Good heat transfer

Lightweight and low cost

Can be hydrophilic coated to reduce frost adhesion

Not ideal for salty seafood (corrodes faster)

Stainless Steel Fins (SS304 / SS316)

Maximum corrosion resistance

Perfect for seafood, shrimp, salty environments

Heavier, lower heat transfer than aluminum

Higher cost

Preferred for harsh IQF applications

Copper Fins

Excellent heat transfer

Expensive

Rarely used in IQF due to cost and corrosion

3. Common Material Combinations (Industry Standard)

For Seafood / Shrimp IQF (HIGHLY RECOMMENDED)

Stainless steel tube + Stainless steel fins (SS304/SS316L)

Full stainless steel coil = best corrosion life in salt environments

Or

Stainless steel tube + Aluminum fins (SS/Al)

Balances corrosion resistance and cost

For Ultra-Hygienic / Washdown IQF

Full SS316L coil with electro-polished surface

4. Coatings to Improve Performance

Hydrophilic coating on aluminum fins

Reduces frost bridging, improves defrost efficiency

Epoxy / phenolic coating

Protects aluminum fins in mildly corrosive environments

Nickel / Teflon coating

Extra protection for seafood IQF coils