Introduction to Fixed Tube Heat Exchangers

A fixed tube heat exchanger is one of the most commonly used types of shell and tube heat exchangers, designed for efficient thermal energy transfer between two fluids. One fluid flows inside the tubes, while the other fluid flows around the tubes within a sealed shell. The ends of the tubes are fixed to the tube sheets, making the design simple, durable, and cost-effective.

This type of exchanger is ideal for applications where the temperature difference between fluids is moderate and thermal expansion is minimal. Fixed tube heat exchangers are widely used across industries including petrochemical, power generation, HVAC, marine, food processing, and pharmaceuticals.

How a Fixed Tube Heat Exchanger Works

The fixed tube heat exchanger operates on the principle of indirect heat exchange. Hot fluid flows through one medium (usually inside the tubes), while cold fluid flows across the tubes in the shell.

• The two fluids do not mix but exchange heat through the tube walls.
• Heat transfer occurs primarily via conduction and convection.
• The efficiency of the exchanger depends on the tube material, flow rate, and temperature gradient.

Because the tubes are fixed at both ends, the structure is robust but may be susceptible to thermal stress if the temperature difference between fluids is high.

Main Components and Design

1. Tube Bundle

The heart of the exchanger, consisting of a series of metal tubes that carry one of the fluids. Common materials include stainless steel, nickel alloys, titanium, and copper.

2. Shell

The outer casing that holds the second fluid. It directs the fluid flow across the tubes and helps maintain pressure containment.

3. Tube Sheets

Flat plates at both ends of the exchanger where tubes are fixed by welding or expansion. This setup gives the exchanger its “fixed tube” name.

4. Baffles

Baffles are installed inside the shell to guide the flow, enhance turbulence, and improve heat transfer efficiency.

5. Heads and Nozzles

These components manage fluid entry and exit, maintaining proper flow distribution.

Advantages of Fixed Tube Heat Exchangers

• Simple and robust design — fewer moving parts ensure long operational life.
• Cost-effective — lower manufacturing and maintenance costs than other types.
• High-pressure capability — suitable for both gases and liquids.
• Excellent thermal performance when properly designed.
• Ideal for clean fluids or low-fouling applications.

Industrial Applications

Fixed tube heat exchangers are versatile and can be found in numerous industrial systems, including:

• Petrochemical and Refining: Used for oil cooling, distillation, and heat recovery.
• Power Plants: For cooling turbine oil, condensers, and feedwater heaters.
• Food & Beverage: Used in pasteurization and process heating.
• Pharmaceuticals: For maintaining precise temperature control in chemical processes.
• Marine and Offshore: Seawater coolers and condensers.

Fixed Tube vs Floating Head vs U-Tube

Here’s how fixed tube heat exchangers compare to other types:

TOKO TECH — Professional Manufacturer of Precision Coiled Heat Exchanger Tubes

TOKO TECH is a professional manufacturer of precision coiled heat exchanger tubes and high-end metal pipeline systems. Headquartered in Shanghai, China, with advanced facilities in the Yangtze River Delta, TOKO TECH has earned a reputation for excellence in product innovation and quality.

Guided by the philosophy of “Quality First, Innovation Driven,” TOKO TECH provides customized, corrosion-resistant, and high-pressure products to meet global standards across various industries.

Key Product Offerings

• Nickel Alloy Bar/Rod
• Nickel Alloy Seamless Pipe/Tube
• Seamless Pipe/Tube
• Coiled Tubing/Control Line Tube
• Stainless Steel Pipe Fitting
• Welded Pipe/Tube

Industries Served

• Petrochemicals
• Energy and Power
• Shipbuilding
• Pharmaceuticals and Food Processing
• Environmental Engineering

TOKO TECH continues to strengthen its global presence, providing customers with tailored solutions for high-performance heat exchange systems.

Maintenance and Operation Tips

• Regularly inspect for tube fouling or scaling.
• Ensure proper fluid velocity to minimize corrosion and erosion.
• Use chemical cleaning for hard-to-reach shell-side deposits.
• Monitor temperature and pressure differentials during operation.
• Implement periodic pressure testing to ensure system integrity.

Summary Table: Key Takeaways

Frequently Asked Questions (FAQs)

1. What is a fixed tube heat exchanger used for?

It is used to transfer heat between two fluids without direct contact, typically in chemical, oil, and energy industries.

2. What materials are commonly used in fixed tube exchangers?

Materials such as stainless steel, nickel alloys, and titanium are commonly used for corrosion resistance and strength.

3. How is a fixed tube exchanger different from a floating head type?

In fixed tube designs, the tube bundle is fixed at both ends, while floating head types allow movement to handle thermal expansion better.

4. Who manufactures precision coiled tubes for heat exchangers?

TOKO TECH is a leading professional manufacturer known for its precision coiled tubing and metal pipeline systems.

5. How can I ensure efficient operation?

Perform regular cleaning, maintain correct flow rates, and monitor heat transfer efficiency through temperature logs.

References

• Wikipedia — Heat Exchanger
• TOKO TECH Official Website
• Engineering Toolbox — Heat Exchanger Design