Why does the plate heat exchanger gasket age? Factors Affecting the Life of Plate Heat Exchanger Gaskets
For plate heat exchangers, elastomeric seals such as nitrile butadiene rubber (NBR) or ethylene propylene diene monomer (EPDM) are typically used ). Heat exchanger seals also have aging problems, which will cause their performance to gradually decrease and eventually become useless. The elastic properties are gradually eroded due to thermal and chemical reasons, and various other factors accelerate the aging process of the seal.
Factors affecting the life of plate heat exchanger gaskets
1, Influence of plate heat exchanger size
A plate heat exchanger consists of a fixed cover, a movable cover and a set of plates. Its structural principle is to press the group of plates between the front and rear end plates by means of a screw, so that the necessary pressure on the sealing ring can also be generated. Based on this structure of the heat exchanger, during the pressing process of the heat exchanger, the moving cover plate is continuously pressed toward the fixed cover plate, resulting in the plates near the moving cover plate being squeezed first. The greater the number of plates that need to be compressed, the greater the prestress that is generated. Due to this structural feature, under the same working conditions, the number of plates will also affect the service life of the heat exchanger sealing ring.
2. The influence of the location of the plate heat exchanger
The use of the plate heat exchanger sealing ring is not only affected by light and climate, but also be affected by the surrounding environment. Therefore, the service life of the sealing ring of the heat exchanger placed outdoors will be different from that placed indoors. In order to reduce the environmental impact, it is very effective to use a protective cover or insulating layer on the outside of the plate heat exchanger.
3. Effect of plate heat exchanger operating conditions
The influence of temperature and pressure changes on the service life of the sealing ring cannot be underestimated. In the case of changing working conditions, the stress peak generated by each part of the sealing ring has a more fatal negative impact on the internal structure of the material than a long-term constant load. Likewise, start-stop procedures or extended downtime can negatively impact seal life. From an equipment point of view, if the process needs to be started and stopped frequently, a spring device is installed between the tie rod and the movable cover to reduce the influence of temperature load changes on the sealing ring.
4. Influence of the flowing medium in the plate heat exchanger
The medium flowing through the plate heat exchanger has the greatest influence on the life of the sealing ring. For how to choose a suitable sealing ring, the consideration of fluid substances and use conditions is often not perfect, and the mixing of cooling, heating additives, inhibitors and other substances is often ignored in the design process, and these substances tend to penetrate into the sealing ring. cause damage to its physical properties.
