How to verify the maintenance boundaries of a jacketed hot and cold exchanger before procurement? Design and selection personnel should pay attention to the following points.
The jacketed structure allows the core to be individually withdrawn for inspection or replacement without dismantling the entire shell, so the system sealing surfaces are not affected. During maintenance, it is only necessary to confirm that the mating surface between the jacket and the core is free of scratches and that the sealing rings are not aged or deformed, to restore the original sealing condition. This structure is preferred for applications involving frequent disassembly, but a low-pressure holding check should be performed after each reassembly.
This model is suitable for non-corrosive media such as conventional industrial water and heat transfer oil. If the medium is a strong acid, strong alkali, or poses a flammable or explosive risk, a different model must be selected and this product must not be used directly. During the design and selection stage, the medium name, concentration, and temperature range should be provided to confirm the compatibility of the jacket material with the core.
With reference to the relevant recommendations of the Code for Design of Thermal Insulation Engineering of Industrial Equipment and Pipelines, the medium temperature fluctuation of tank trace heating systems should be controlled within a reasonable range. During maintenance, the deviation between temperature control instrument and sensor readings should be checked periodically to avoid changes in medium properties or local overheating caused by excessive temperature differences. It is recommended to check the temperature record curve once per quarter.
At sites with high disassembly frequency, a record of core withdrawal inspections should be established. Inspection items include: the degree of fouling on the core surface, whether there is sediment on the inner wall of the jacket, and whether the elasticity of the seals has decreased. If fouling is found to affect heat exchange efficiency, circulating cleaning with a neutral cleaning agent may be used; strong acid or strong alkali cleaning solutions are prohibited.
When the equipment is shut down for a long period, the residual medium in the shell side and tube side should be drained, and the inner cavity should be kept dry. Before restarting, check whether the seals have failed due to long-term compression, and replace the sealing rings if necessary. For winter shutdown in northern regions, confirm that draining is thorough to prevent residual water from freezing and cracking the jacket.
