Bare Tube Evaporator in Seafood Processing Industry

Bare Tube Evaporator in Seafood Processing Industry

Bare tube evaporators are primarily used in low-temperature environments where direct, efficient cooling is essential.

Key use cases include:

a. Quick Freezing (IQF & Bulk Freezing)

Seafood requires rapid freezing to minimize ice crystal formation (large crystals damage cell structures, leading to texture loss and drip loss during thawing). Bare tube evaporators excel here because:

They operate in ultra-low temperature (ULT) environments (-30°C to -40°C), ideal for freezing seafood within minutes to hours.

Common setups:

Blast freezers: Bare tube coils are arranged in banks to circulate cold air (blown by fans) over seafood batches (e.g., whole fish, shrimp) on conveyors or racks. The uncoated tubes maximize heat transfer efficiency, ensuring fast temperature drop.

Immersion freezers (indirect): In some cases, bare tubes are submerged in a food-safe coolant (e.g., glycol solution), which then circulates around seafood to freeze it—critical for delicate products like scallops or squid that need gentle cooling.

b. Cold Storage & Holding Rooms

After freezing, seafood is stored in cold rooms (-18°C to -25°C) to maintain long-term freshness. Bare tube evaporators are used here to:

Maintain stable, uniform temperatures (no hotspots) across large storage spaces (e.g., warehouses for frozen fish pallets).

Avoid frost buildup on coils (a risk with finned evaporators, which block airflow)—critical for consistent cooling in high-humidity seafood storage.

c. Chilling of Fresh Seafood

For seafood not immediately frozen (e.g., fresh fish for local markets), bare tube evaporators are used in chilling rooms (0°C to 4°C) to:

Rapidly lower the temperature of freshly caught seafood (from ~10°C–15°C to safe levels) within 2–4 hours, slowing bacterial growth and extending shelf life.

Cool processing water (e.g., for washing or blanching seafood) via indirect heat exchange with bare tube coils.