The plate heat exchanger is a detachable device composed of many herringbone corrugated heat transfer plates pressed by rubber gaskets at certain intervals.Process parameters such as system operating temperature, flow rate and concentration are beyond the design conditions, and the operating temperature is far beyond the applicable range of the material.Plate heat exchangers that use saturated steam as the primary heat source are prone to plate corrosion and lead to internal leakage during operation.This is because the steam temperature is high, and it is easy to cause the rubber seal to fail at high temperature during the operation of the equipment, causing steam leakage and rapid condensation in the second sealing area.With the continuous leakage, the condensed residual liquid will accumulate more and more, and the areas with higher cl mass concentration will be formed locally to achieve the corrosion conditions that destroy the passivation layer on the surface of the plate. Because the internal stress formed by the cold stamping of the plate in this area is relatively large, when the surface passivation layer is destroyed, the internal stress acts to cause stress corrosion.
(1) Improper selection of plate heat exchanger plates causes cracks or perforations in plate corrosion.
(2) The operating conditions of the plate heat exchanger do not meet the design requirements.
(3) The residual stress after cold stamping of the heat exchanger plate and the too small clamping size during assembly cause stress corrosion.
(4) There is a slight leakage at the leak groove of the heat exchanger plate. It causes the harmful substances (such as C1) in the medium to concentrate and corrode the plates to form internal leakage.