Fluid’s mixing in plate heat exchangers

Many times I’m asked if fluids can mix in a plate heat exchanger. As I’m explaining in the new video tutorial on our Tempco YouTube channel (please turns on English subtitles), the only way it can happen is when a plate break occurs, due to corrosion of the plates’ material or cracking.

Further cases are avoided by the intelligent design of the gaskets in a heat exchanger. Fluids cannot mix indeed due to the break of a gasket, because gaskets in plate heat exchangers always offer a double protection.

Gaskets of a plate heat exchanger offer protection all along the perimeter of a plate and also in the nozzle area, where the liquid flows from a plate to another. Here, there is a double gasket, and in addition it offers a sort of drain toward the outside, so that in case one part of the gasket breaks there will be a leakage of liquid on the external side of the heat exchanger, alerting that something’s wrong is happening. Is then sufficient to stop the exchanger from operating and extract the two plates where the drop was detected, then close again the exchanger and re-starting the plant.