Cleaning Tubular Heat Exchangers requires selecting the appropriate method based on the type of scale and material, balancing cleaning effectiveness with equipment protection. The following are specific operating guidelines:
Physical cleaning is suitable for loose scale or blockages caused by impurities. High-pressure water jet cleaning is used, with the pressure controlled at 15-25 MPa. The water is directed at the inside of each tube to rinse away surface scale and deposits. For stubborn impurities inside the tubes, specialized cleaning tools can be used, avoiding rough handling that could scratch the tube walls. This method requires no chemical agents and is suitable for most materials, including stainless steel and carbon steel.
Chemical cleaning is for hard scale (such as carbonates and sulfates). First, select an appropriate cleaning agent based on the scale composition. Acidic cleaning agents (such as hydrochloric acid solution) should be controlled at a concentration of 5%-10%, and corrosion inhibitors should be added to protect the equipment. During cleaning, the cleaning agent is circulated into the system, soaking for 2-4 hours before draining. Then, rinse repeatedly with clean water until neutral to prevent residual agents from corroding the pipes.
Key precautions for cleaning shell-and-tube heat exchangers should not be ignored. Before cleaning, the machine must be shut down and depressurized, and related pipelines isolated to prevent chemical contamination of other equipment. After cleaning, the Tubular Heat Exchanger's sealing should be checked, and the heat exchange efficiency should be tested to see if it has recovered. It is recommended to determine the cleaning cycle based on operating conditions, generally every 3-6 months. In scenarios with high levels of impurities in the medium, the cycle should be shortened.
