Corrosion and cavitation in tube furnaces during the heating of water-contaminated oil

Abstract

Tube furnaces in coking plants heat tar and oils, playing a crucial role in steam conservation. However, heating water-contaminated oil in these furnaces leads to severe corrosion, marked by hemispherical cavities. Light microscopy reveals no intergranular corrosion, but cavitation-induced damage is evident. Water contamination increases vapor phase, especially at low flow pressure and high temperature, promoting cavitation and erosion. Hydraulic calculations show that under 1 bar pressure, 20% water content, and 160°C, cavitation is inevitable, accelerating corrosion, particularly with ammonium chloride. Electrochemical and gravimetric analyses confirm high corrosion rates, emphasizing the importance of controlling water contamination to prevent equipment degradation.