Double Pipe Heat Exchanger for Flue Gas (Gas to Air) Heat Transfer

Double Pipe Heat Exchanger for Flue Gas (Gas to Air) Heat Transfer

A double-pipe heat exchanger transfers heat from hot flue gas to cooler air by flowing the flue gas through an inner pipe and the air through the annular space between the inner and outer pipes, or vice-versa. This simple, compact design allows for counter-flow or parallel flow of the two fluids, transferring heat through the inner pipe's wall. For enhanced performance, internal modifications like fins, threads, or a helically baffled design can increase heat transfer and flow resistance.

How it Works

Concentric Pipes: The core of the design is an inner tube surrounded by a larger outer pipe.

Fluid Flow: Hot flue gas flows through one pipe (typically the inner pipe), while the cooler air flows through the annular space between the two pipes.

Heat Transfer: Heat is transferred from the hot flue gas to the cold air through the wall of the inner pipe.

Flow Configuration: The two fluids can flow in a counter-current (opposite directions) or parallel flow (same direction) configuration.

Advantages

Compact & Cost-Effective: Double-pipe heat exchangers are compact, which makes them cost-effective for smaller heat duties.

Simple & Easy to Maintain: Their simple design makes them easy to operate, maintain, and repair.

High Pressure & Temperature Capability: The construction allows them to withstand high pressures and temperatures, suitable for industrial applications.

True Counter-flow: The hairpin design allows for a true counter-flow pattern, increasing heat transfer efficiency.