Which heat exchanger type is commonly referred to as a “hairpin” exchanger in process industries?

Introduction / Context:
Heat exchanger nomenclature often reflects construction. The “hairpin” exchanger name arises from its characteristic U-shaped, two-pipe assembly frequently used for compact duties and high-pressure services.

Given Data / Assumptions:

• Standard industrial designs and terminology.
• Focus on common, widely accepted names.

Concept / Approach:
A double-pipe exchanger consists of one pipe inside another, with the flow often arranged to loop back in a U-bend, forming a hairpin-like geometry. This design allows ease of maintenance and modularity for small duties.

Step-by-Step Solution:
Identify which construction naturally forms a hairpin loop.Double-pipe with U-bend matches the description.Other listed designs do not inherently resemble a hairpin in standard form.

Verification / Alternative check:
Vendor catalogs and textbooks routinely label U-bend double-pipe units as hairpin exchangers.

Why Other Options Are Wrong:

• Finned: Refers to extended surfaces, not the overall geometry.
• Plate-type: Stack of plates; no hairpin shape.
• Regenerative: Stores heat alternately; construction differs.
• Scraped-surface: Agitated surface for viscous fluids; geometry not hairpin.

Common Pitfalls:
Confusing hairpin with U-tube bundles in shell-and-tube exchangers; the term “hairpin” conventionally maps to double-pipe modules.

Final Answer:
Double-pipe exchanger