Regarding plate heat exchangers
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The heat medium in the plate heat exchanger is distilled water, while the cold medium is seawater. After operation for some time, it was found that seawater was leaking to the distilled water side, affecting the quality of the distilled water. The technicians at the factory said it was caused by a problem with the gasket used for sealing the plates, but I think if there’s an issue with that gasket, there should be leakage to the outside environment rather than internal leakage. What are the causes of internal leakage in plate heat exchangers? I hope someone with more experience can give me some advice. I would be extremely grateful, thank you! !
It is possible that the seal strip on the seawater side panel has been damaged, causing seawater to leak through the gap; it will be necessary to remove the panel in order to check this
There may be an issue with the material chosen for the plates; corrosion leads to perforations in these plates, resulting in internal leakage, and this has nothing to do with the gaskets
Generally, gaskets have observation holes, so if there is a leak, it can be seen from the outside. If your heat exchanger has been in operation for a long time, it’s possible that the plates have been corroded or that the gaskets have aged; the exact situation needs to be checked by taking it apart
If there is a problem with the gasket in a plate heat exchanger, there should be external leakage. If there is an internal leak, it is usually because one half of the disc has perforated. What material is the board you’re using? Titanium plates are generally used for seawater as a heat exchange medium
There is a high likelihood of perforation in the plates; generally, the high chloride content in seawater has a strong corrosive effect on stainless steel plates； If the gasket is damaged, there is usually an external leak
The pressure difference between the plate side and the tube side of a plate heat exchanger is strictly specified at the time of its manufacture; if this pressure difference is too high, it may cause the plates to bulge and deform, leading to leaks. Personal opinion, for reference only :)
If there’s no leakage from the observation hole of the gasket, it’s basically the plate that’s damaged
Internal leakage, plate perforation; external leakage, damaged seal strip or insufficient compression force
External leakage = Crystals/leakage on the outside; Internal leakage = Hole in the plate ------------------------------ Additionally, you can also determine whether the X fluid flows in the direction of the Y fluid when there is a hole in the plate by comparing pressures