The reason for leakage in a graphite heat exchanger caused by the heat exchange tube

Most domestic shell and tube graphite heat exchangers use phenolic graphite pressed tubes, which are prepared by mixing and extruding artificial graphite powder and phenolic resin in a certain proportion. They are dense and do not require resin impregnation or surface machining, but the tank body itself must be completely cured, have a smooth surface, no cracks, no sand holes, etc.

When installing a heat exchanger, if the pressure test and surface inspection of a single tube are not strict, graphite heat exchanger tubes that do not meet the above requirements may be misused. The heat exchange tubes are fixed to the tube sheet in a bonded form, forming a constraint effect of the tube bundle on the tube sheet.

In production and use, the tube plate will inevitably deform under the pressure of the medium, and the reasons for this are:

One is the occurrence of longitudinal stretching or compression in different directions between connected devices;

Secondly, as the deformation of various components of the heat exchanger becomes uneven, the tube sheet bends, causing the heat exchange tubes to bend. At this point, the closer the tubes are to the edge, the greater the bending.

If defective graphite profiled tubes are arranged in areas with significant deformation under stress, the graphite heat exchanger is prone to fracture and leakage.