A tube-in-tube heat exchanger is a type of heat exchanger that consists of two concentric pipes, where one pipe is placed inside the other. The inner pipe carries one fluid, while the outer pipe carries a different fluid. Heat is transferred between the two fluids through the wall of the inner pipe.
tube-in-tube heat exchangers are specifically designed for heating and cooling of sludge that contains fibers and particles, making it ideal for most wastewater sludge.

Advantages
· Compact Design: The concentric arrangement saves space compared to other heat exchangers, making it ideal for applications where space is limited.

· Separation of Fluids: The two fluids do not mix, making the pipe-in-pipe heat exchanger suitable for situations where contamination or mixing of fluids must be avoided.

· High Pressure and Temperature Resistance: This design is often used in high-pressure, high-temperature environments, making it suitable for industries such as oil and gas or chemical processing.

· Simple Construction: Compared to more complex heat exchanger designs, the pipe-in-pipe system is relatively simple to manufacture and install, making it cost-effective in certain applications.

Water-Cooled vs. Air-Cooled Heat Exchangers

Which One to Choose? 

● Air-cooled systems are recommended for water-scarce or high-temperature regions, offering low maintenance costs and zero water consumption.

● Water-cooled shell-and-tube exchangers are ideal when lower outlet temperatures, compact installation, or reliable water supply are required.

● We also offer hybrid (dry/wet) air-cooled systems for enhanced performance in hot climates.

Supporting Products:

● Air Fin Cooler / Dry Cooler
● Shell and Tube Heat Exchanger
● Plate Heat Exchanger
● Hybrid Cooling Systems (Dry + Spray)

Shell-and-Tube Water-Cooled Heat Exchangers
Advantages

● High cooling efficiency: outlet temperature can approach wet-bulb conditions

● Compact design: smaller footprint, easily integrated into tight spaces

● Stable performance: unaffected by ambient temperature fluctuations

● Quiet operation: no fans, minimal noise

Limitations

● High water consumption and pollution risk

● Needs water source, pumps, pipelines, and treatment systems

● Corrosion & scaling: frequent maintenance and chemical treatment required

● Total shutdown upon power failure

● Biological growth risk in warm climates

Air-Cooled Heat Exchangers (Dry Coolers, Air Fin Coolers)
Advantages

● Environmentally friendly: no water consumption, no thermal or chemical pollution

● Site flexibility: suitable for arid areas or water-scarce regions

● Easy maintenance: corrosion-free, scaling-free, long service life

● Lower operating costs: air has low resistance and no treatment cost

● Passive cooling: retains 30–40% natural cooling even when power is off

Limitations

● Cooling is limited by dry-bulb temperature; it cannot cool below ambient

● Requires a larger footprint due to low air-side heat transfer

● Affected by weather: wind, sunlight, and seasonal changes impact performance

● Noise: due to fans and airflow

● Requires finned tubes and specialized fan systems