Rectangular heat exchangers offer some features that benefit heat recovery applications in wastewater.

1.         They offer a larger circumference compared to tube in shell. For the same flow area, there is a larger heat transfer surface.

2.         They offer a smaller footprint than a tube, which means less area is required.

3.         More turbulence flow is available than in a tube or spiral unit, which provides better heat transfer due to zig-zag channels.

4.         The non-block design means there’s no spacer or obstacles like in a spiral type.

5.         One feature ― 3" minimum gaps ― results in no sludge blockage. Often this eliminates the need for blades used to grind sludge.

6.         Little maintenance is required.

7.         Modular systems can be used for water-to-sludge or sludge-to-sludge heat recovery.

 8.         Heat recovery can have payback within a year.