4.1 Replace the spiral plate heat exchanger with serious fouling in time to ensure the normal operation of production.
4.2 Clean the spiral plate heat exchanger with serious fouling. The serious fouling of the spiral plate heat exchanger is the cooling water channel, and there is relatively little scaling in the lean oil channel. Therefore, it is important to clean the scale in the cooling water channel.
Flushing: Before pickling, open the heat exchanger to be flushed so that there are no impurities such as mud and scale inside the heat exchanger, which can improve the effect of pickling and reduce the acid consumption of pickling. Pour the cleaning liquid into the cleaning equipment, and then pour it into the heat exchanger.
Pickling: statically soak the heat exchanger filled with acid solution for 2h, and then continuously and dynamically circulate it for 3~4h. During this period, the positive and negative cleaning is performed alternately every 0.5h. After pickling, if the pH of the acid solution is greater than 2, the acid solution can be reused.
Alkaline washing: After the pickling is finished, prepare it with NaOH, Na2CO3, Na3PO4, and demineralized water in a certain proportion. Use dynamic circulation to perform alkaline washing on the heat exchanger to achieve acid-base neutralization and make the heat exchanger plates No more corrosion.
Water washing: After the alkali washing is completed, the heat exchanger is repeatedly rinsed with clean demineralized water for 0.5h to thoroughly rinse the residue in the heat exchanger.
Record: During the cleaning process, the time of each step should be strictly recorded to check the cleaning effect. After cleaning, the heat exchanger can be used only after it has passed the pressure test.
4.3 Strengthen the use and management of spiral plate heat exchangers
Before operation, the residual air in the equipment should be drained to avoid affecting the heat exchange effect. Over-temperature and over-pressure operation are strictly prohibited. When one of the following conditions occurs, the operation should be stopped immediately: pressure and temperature exceed the design value; weld cracks, bubbling, deformation, leakage or other abnormal phenomena; safety accessories fail; accidents occur nearby, Affect safety.
