What is Shell and Tube Condenser?
Shell and Tube Condenser: Short Notes
1. Basic Definition
A Shell and Tube Condenser is a specific type of heat exchanger designed to condense a gaseous substance (vapor) into its liquid state by transferring its latent heat of vaporization to a coolant fluid. It is a direct application of the standard shell and tube heat exchanger principle, optimized for phase change.
2. How It Works
- The vapor (e.g., refrigerant vapor or steam) enters the condenser and comes into contact with the cool tubes.
- The vapor releases its heat to the cooler fluid flowing inside the tubes.
- As the vapor loses heat, it undergoes a phase change, condensing into a liquid on the exterior surface of the tubes (typically on the shell side).
- The condensed liquid (condensate) drips down and is collected at the bottom of the shell for drainage.
- The coolant (e.g., water or air) inside the tubes absorbs the heat and leaves at a higher temperature.
3. Common Configurations (Which side is which?)
The design depends on the application:
- Refrigerant in the Shell (Most Common in HVAC&R):
- Shell Side: Refrigerant vapor is condensed.
- Tube Side: Cooling water absorbs the heat.
- Why? The shell provides a large volume for the vapor to condense, and the refrigerant’s properties often necessitate this arrangement.
- Steam in the Shell (Power Plant Surface Condenser):
- Shell Side: Exhaust steam from a turbine is condensed.
- Tube Side: Cooling water (often from a river, lake, or cooling tower) flows through the tubes.
- Why? Creating a large vacuum in the shell is easier, which is critical for turbine efficiency.
- Steam in the Tubes (Less Common):
- Tube Side: Steam is condensed.
- Shell Side: Cooling water.
- Why? Used for specific industrial processes where condensate purity is critical, as it’s easier to contain within the tubes.
4. Key Components (Similar to STHE, with nuances)
- Shell: Houses the refrigerant or steam vapor.
- Tubes: Contain the cooling water.
- Tube Sheets: Seal the ends of the shell.
- Baffles: Direct the vapor flow to prevent short-circuiting and to support the tubes. Their design is crucial for efficient condensation.
- Hot Well: A reservoir at the bottom of the condenser (in large units) that collects the condensate.
- Vent: A connection to remove non-condensable gases (like air), which severely reduce condensation efficiency.
5. Advantages
- High Efficiency: Excellent heat transfer due to the latent heat involved in condensation.
- High Pressure Handling: Can handle the high pressures of refrigerants and steam.
- Robust and Durable: Built to last for decades in demanding applications.
- Large Capacity: Can be designed for very large loads (e.g., powering a city).
6. Primary Applications
- Power Plants: The surface condenser is a critical component, condensing steam from a turbine to create a vacuum and recycle feedwater.
- HVAC and Refrigeration Systems: Used in large chillers for air conditioning in buildings, district cooling, and industrial refrigeration.
Chemical and Process Industries: For condensing process vapours and solvents in distillation columns and other operations