n Air Gas plants, which typically produce nitrogen (N2), oxygen (O2), and argon (Ar), several types of heat exchangers are commonly used for various applications. Here are some of the typical types of heat exchangers used in such plants, often designed and specified according to standards like ASME Section VIII Div 1 & Div 2, TEMA, API 660, HTRI, and PVElite:

1. Shell and Tube Heat Exchangers:

   • Straight Tube (TEMA type AEW, BEW): Used for general heating and cooling duties.

   • U-Tube (TEMA type BEU): Commonly used for heating or cooling clean fluids where thermal expansion is a concern.

   • Fixed Tube Sheet (TEMA type AES, BES): Suitable for high-pressure applications where cross-contamination must be avoided.

2. Plate Heat Exchangers (PHE):

   • Compact and efficient for heat transfer between fluids with a small temperature difference.

   • Often used in gas processing where space and efficiency are critical.

3. Air Cooled Heat Exchangers (ACHE):

   • Used to cool process fluids with ambient air, eliminating the need for water cooling.

   • Suitable for outdoor installations and in areas where water scarcity is a concern.

4. Finned Tube Heat Exchangers:

   • Enhance heat transfer by increasing surface area through fins attached to the tubes.

   • Commonly used for gas cooling or heating applications.

5. Plate-Fin Heat Exchangers:

   • Compact and lightweight with high heat transfer efficiency.

   • Suitable for cryogenic applications and where compact design is essential.

6. Regenerative Heat Exchangers:

   • Utilize the heat stored in a solid matrix (e.g., ceramic or metal) to preheat or cool process streams.

   • Efficient in applications where very high temperatures or large volumes of gases need treatment.

7. Heat Recovery Steam Generators (HRSG):

   • Recover waste heat from gas turbines to generate steam, which can be used for various purposes such as power generation or process heating.

These heat exchangers are designed to meet specific process requirements such as pressure, temperature, flow rates, and types of fluids (N2, O2, Ar) handled in Air Gas plants. The design codes and standards mentioned (ASME Section VIII Div 1 & Div 2, TEMA, API 660, HTRI, PVElite) ensure that the heat exchangers are safely designed, fabricated, and operated according to industry best practices and regulatory requirements.