Core Structure of Shell-and-Tube Heat Exchangers

The shell-and-tube heat exchanger is a widely used industrial heat transfer device. Its core structure primarily consists of the following five key components:

1. Shell

   Serves as the outer pressure vessel, designed to withstand internal pressure

   Provides flow passage for the shell-side fluid

   Typically made of high-strength carbon steel or stainless steel to ensure safety under high temperature and high-pressure conditions

2. Tube Bundle

   Composed of hundreds of parallel arranged heat exchange tubes (common tube diameters range from 19–25 mm, with lengths up to 6 meters)

   Acts as the primary medium for heat transfer and constitutes the main site of thermal exchange

   Tube layout patterns commonly include triangular, square, or concentric arrangements, which directly influence heat transfer area and fluid flow characteristics

3. Tube Sheets

   Mounted at both ends of the shell to support and seal the tube bundle

   Separate the tube-side and shell-side fluids to prevent mixing

   Ensure structural integrity and sealing between the tube bundle and shell

4. Heads (End Covers / Channel Covers)

   Located at both ends of the shell, providing sealing function

   Create independent spaces for the tube-side and shell-side fluids

   Responsible for distributing and controlling the inlet and outlet of the tube-side fluid

   Facilitate equipment assembly, disassembly, cleaning, and maintenance

5. Baffles (Baffle Plates)

   Installed perpendicular to the tube bundle, typically in segmental (e.g., single-segmental) or circular designs

   Guide the shell-side fluid to change direction multiple times, creating spiral or Z-shaped flow patterns

   Enhance turbulence by 3–5 times, improving heat transfer coefficients by 2–3 times

   Simultaneously provide mechanical support to the tube bundle, preventing vibration and bending

These core components work together to allow hot and cold fluids to flow through the tube-side and shell-side channels respectively, enabling efficient heat transfer across the tube walls. Depending on specific process requirements, shell-and-tube heat exchangers can be configured in various structural types—such as fixed-tube-sheet, floating-head, or U-tube designs—to suit different operating conditions.