Tranter Plate Heat Exchanger Models
The common rubber circular ring is a self-sealing principle, and its seal can be maintained until the ring deforms or softens. This is because the pressure on the circular ring is the seal against the micro-defects.The seal of the PHE rubber gasket is different. The sealing the gasketed phe mainly depends on the comparison between the instantaneous sealing stress caused by the gasket compression and the operating pressure of the plate heat exchangers. The sealing stress can be maintained at the operating pressure and the seal can be maintained. Otherwise, the leakage occurs.
The elasticity of rubber gasket is different from metal spring, it’s viscoelastic materials. This means that force relaxation happened when the rubber is deformed for a long period of time. That is, the sealing stress decays with time under constant tension or pressure. Higher stress relaxation is an important factor in limiting the service life of the plate heat exchanger gasket. There are two kinds of stress relaxation, one is physical relaxation which is caused by the rearrangement between the molecules of the polymer and filler particles,This rearrangement gradually approaches equilibrium with the rubber deformation,and the logarithm of the sealing stress and time is Linear relationship. The second is chemical relaxation, which is caused by the cracking of chemical bonds in the glue network. Oxidation and temperature are important factors for this kind of relaxation. Therefore, the rate of stress relaxation depends to a large extent on the temperature and the applicable temperature range for each rubber gasket.