If the material of the plate heat exchanger nozzle is not satisfactory, the plate heat exchanger gap will be caused by residual stress and acid autocatalysis, and the non-metallic inclusions along the crystal will cause stress concentration and coarse grain structure.In order to prevent cracks in the plate heat exchanger, the improvement of the material of the plate heat exchanger nozzle must be carried out to ensure the normal use of the equipment.
(1) Material control
Strictly control material quality by adding stabilizing elements or reducing carbon content.Control grain boundary adsorption and inhibit grain boundary precipitation: heat treatment temperature, time and temperature change rate should meet the requirements to reduce the precipitation of chromium-containing carbides, control grain size and refine grains, and reduce the possibility of corrosion.
(2) Structural improvement
Try to avoid the formation of occlusion space. The gap between the tube plate and the tube of the plate heat exchanger may be considered for sealing treatment during design. Seal welding is recommended, and stress relief treatment is performed after welding.
(3) Working condition medium control
Strict control of impurities in the plate heat exchanger medium can be controlled by the process to a concentration that causes stress corrosion.If cracks appear in the nozzle of the plate heat exchanger, it will have an impact on its use. The material of the nozzle is improved in time to solve the situation and avoid affecting the normal use of the equipment.