Reboiler is used to provide heat to bottom of distillation column. Boil liquid to generate vapor which are returned to the column to drive the distillation separation. Distillation is a process of separating the component from a liquid mixture by selective evaporation and condensation. Industrial distillation is typically performed in large, vertical cylindrical columns known as distillation tower or distillation column. Industrial use reflux to achieve a more efficiency. Fouling accumulates on surface tube side, cause heat transfer coefficient is decrease. Surface temperature of reboiler may be make fouling.