50 ton Bare Tube Condenser In an Ice Machine

50 ton Bare Tube Condenser In an Ice Machine

Ice machines (e.g., cube ice, flake ice, or tube ice machines) rely on a closed refrigeration loop to freeze water, and the condenser is one of four key components (compressor → condenser → expansion valve → evaporator). Its specific role:

The compressor compresses low-temperature refrigerant vapor into a high-temperature, high-pressure superheated vapor (e.g., 50–70°C for R404A or R513A refrigerants).

This superheated vapor flows into the bare tube condenser, where it releases heat to a cooling medium (usually water or air) and condenses into a high-pressure liquid refrigerant (e.g., 30–40°C).

The liquid refrigerant then moves to the expansion valve, which reduces its pressure/temperature before it enters the evaporator (where it absorbs heat from water, freezing it into ice).

Without an efficient condenser, the refrigerant cannot condense properly—leading to high compressor discharge pressure, reduced cooling capacity, and even compressor burnout.

Bare tube condensers are defined by their smooth, finless metal tubes, which are arranged in bundles or coils to maximize heat transfer area. Their design is optimized for ice machine-specific constraints (e.g., compact spaces, water/air cooling, and resistance to scale buildup).

Bare tube condensers in ice machines are primarily water-cooled (most common for commercial/industrial ice machines) or air-cooled (for small, space-constrained units). Their working principles differ based on the cooling medium:

A. Water-Cooled Bare Tube Condensers (Most Common)

Water is a more efficient heat transfer medium than air (thermal conductivity of water: ~0.6 W/m·K; air: ~0.026 W/m·K), making this design ideal for high-capacity ice machines (e.g., 1–50 ton/day output).

Refrigerant Flow: High-temperature refrigerant vapor enters the condenser’s tube bundle through the refrigerant inlet header, flowing inside the bare tubes.

Water Flow: Cooling water (from a municipal supply, cooling tower, or well) is pumped into the shell side of the condenser, flowing countercurrent to the refrigerant (water enters near the refrigerant liquid outlet, exits near the vapor inlet). This countercurrent flow maximizes the temperature difference between the refrigerant and water, boosting heat transfer efficiency.

Heat Transfer: Heat from the refrigerant (inside the tubes) is conducted through the smooth copper tube walls to the water (outside the tubes). The refrigerant condenses into a liquid as it releases heat, while the water absorbs heat and exits the condenser at a higher temperature (e.g., 35–45°C).

Liquid Refrigerant Collection: The condensed liquid refrigerant flows to the outlet header and is sent to the expansion valve.

B. Air-Cooled Bare Tube Condensers (Small Ice Machines)

Used for small ice machines (e.g., under 1 ton/day, such as countertop cube ice makers) where water supply is limited.

Refrigerant Flow: Same as water-cooled—refrigerant vapor flows inside the bare tubes.

Air Flow: A fan blows ambient air over the exterior of the bare tube bundle, forcing air to flow across the smooth tube surfaces.

Heat Transfer: Heat from the refrigerant is conducted through the tube walls to the moving air, which carries the heat away. The refrigerant condenses into liquid, while the heated air is discharged to the environment.