Plate heat exchanger gasket swelling
When it comes to the swelling of the sealing gasket of the plate heat exchanger, we may not be very familiar with it. It doesn't matter. I can give you an example. We all know that orange juice drops on the inflated balloon, and the balloon will burst immediately. In fact, this is the role of swelling. A more reasonable solution is that when the rubber balloon is partially exposed to organic substances such as limonene, this part of rubber will be swelled, resulting in reduced strength, and the rubber will become uneven, The balloon burst under the action of the internal pressure. At this time, the gas filled inside the balloon burst out of the crack in a very short time - the balloon burst.
The reason is the same. The swelling of the sealing gasket of the plate heat exchanger means that the unvulcanized rubber can be dissolved in the solvent with similar solubility parameters. For vulcanizates, because chemical crosslinking makes rubber macromolecules connected into three-dimensional network structure, it can only absorb the solvent to gradually swell and reach the equilibrium value in the solvent. This phenomenon is called "swelling" of rubber. The volume after swelling can reach several times the volume of rubber. And accompanied by the loss of mechanical strength. The swelling of vulcanizate is related to its crosslinking density. When absorbing the solvent, the crosslinking network of vulcanized rubber also expands to produce the elastic shrinkage force that extrudes the solvent out of the network. When the pressure of solvent diffusion and penetration is equal to the elastic shrinkage force of the crosslinking network, the swelling equilibrium is reached.
Therefore, the reason for preventing the expansion of the sealing gasket of the plate heat exchanger is that the material corresponding to the medium used is different, and the expansion will occur. For example, the use of EPDM in the oil medium is easy to cause problems. For example, some cleaning agents, such as high-temperature steam water heat exchanger, are prone to scale, and the heat exchange efficiency is reduced, so it is necessary to dredge and clean. Therefore, it is necessary to purchase something that does not harm the gasket.
