Many plants can cut energy costs considerably by replacing their shell-and-tube reboilers or steam heaters with compact heat exchangers. The higher thermal efficiency of compact heat exchangers often allows you to use a lower temperature heating medium compared to shell-and-tubes. Switching to lower grade steam will cut energy costs in most cases.
A refinery asked Alfa Laval to evaluate the possibilities of using lower grade steam in their sour water stripper unit.
Exchanging the existing shell-and-tube for a Compabloc allowed the refinery to switch heating medium from medium-pressure steam at 180°C (356°F) to low-pressure steam at 138°C (280°F).
The stripper column operates at 127°C (261°F) and Compablocs are capable of handling temperature approaches as close as 3°C (5.4°F). This means the steam temperature in this example could have been as low as 130°C (266°F).
As well as cutting energy costs, the new Compabloc also had a much smaller installation footprint.