External corrosion and scaling of the tube bundle in the heat exchanger for the associated hot water in the first stage of constant pressure/constant vacuum units in the petrochemical industry
Thread Content
The image below shows the tube bundle of the heat exchanger for associated hot water in the constant pressure/constant reduced pressure unit 1 of the petrochemical industry. The model is YB700-130-16/16-2, with the tube bundle made of 10# steel. The operating condition is that the tube side carries hot water, while the shell side remains at constant temperature ； The operating temperature is 90 degrees in the tube side and 130 degrees in the shell side ； The pressure in the tube side is 0.5 MPa, and that in the shell side is 0.57 MPa. This tube bundle has been in use for over 2 years; external corrosion and coking have occurred on it, and numerous corrosion pits have appeared on the metal surface beneath the coking, affecting its performance. Common first-line oils have relatively low boiling points and lighter components; they mainly include jet fuel (aviation kerosene), lamp kerosene, solvent oils, raw materials for fertilizers, feedstocks for ethylene cracking, or special diesel fuels. Often, surface corrosion is influenced by H2S-HCl-H2O, leading to corrosion of the metal surface.
PEEK and PI materials are gradually being adopted in the chemical industry. Thanks to their excellent corrosion resistance, high temperature tolerance, and high strength, they can replace certain metal materials. Although their cost is high, they have a long service life, resulting in low maintenance costs and overall lower operating expenses. Jiangsu Junhua specializes in the production of PEEK and PI materials; for more information, please contact 13921798085
The water quality is hard; moreover, the heat exchanger reaching a temperature higher than the designed level causes the water to vaporize and form scale