What Is The Recommended Fin Spacing for IQF Evaporators Used in Shrimp Processing?

What Is The Recommended Fin Spacing for IQF Evaporators Used in Shrimp Processing?

Recommended Fin Spacing for IQF Evaporators – Shrimp Processing

For shrimp IQF freezing (peeled / unpeeled / cooked / raw), the industry standard and most recommended fin spacing is:

Primary Recommendation

Fixed fin pitch: 10–12 mm

Variable (graduated) fin pitch: 16–10 mm or 18–9 mm (preferred for long running time)

Breakdown by Application

General raw shrimp (most common)

Fin spacing: 10 mm

Balances good heat transfer and moderate frost buildup.

Peeled / high-moisture / wet shrimp

Fin spacing: 12 mm

Wider spacing reduces frost blockage from heavy moisture release.

Cooked shrimp (lower moisture)

Fin spacing: 8–10 mm

Higher heat transfer efficiency, acceptable frosting rate.

Large-scale / long-production-run IQF tunnels

Inlet (high frost zone): 16–18 mm

Outlet (low frost zone): 8–10 mm

Extends defrost intervals.

Key Reason for Shrimp

Shrimp releases high moisture during flash freezing, leading to rapid frost growth on coils.

Too narrow (<8 mm): fins block quickly, frequent defrost, low efficiency.

Too wide (>14 mm): reduced heat exchange, slower freezing, lower IQF quality.