Plates are an important component of plate heat exchangers. Their
main functions are to isolate media and conduct heat exchange. The
main materials of plates include stainless steel (304/304L,
316/316L, 254SMO), titanium, nickel, titanium - palladium alloy,
Hastelloy, etc.
Each plate consists of two components.
- Metal Plate: The metal plate is a thin metal sheet with corrugations, sealing
grooves, and corner holes pressed on it. It is an important heat -
transfer element. The corrugations can not only enhance heat
transfer but also increase the strength and rigidity of the thin
plate, thereby improving the pressure - bearing capacity of the
plate heat exchanger. Moreover, they can make the liquid flow in a
turbulent state, reducing the formation of sediments or fouling and
playing a certain "self - cleaning" role.
- Sealing Gasket: It is installed in the gasket groove around the plate, sealing
the periphery between the plates to prevent fluid from leaking
outwards (click to view the causes and solutions for external
leakage of plate heat exchangers). According to the design
requirements, it also seals some of the corner holes, enabling hot
and cold media to flow in their respective channels.
Plates are all formed by stamping at one time using a mold. Only
plates formed at one time have the same precision. Therefore, there
are uniform metal point contacts between plates, ensuring that the
plate heat exchanger can operate normally under relatively high
pressure and withstand the pressure impact of the system.
The gaskets of plate heat exchangers are a relatively complex
polymer system, usually composed of different components such as
rubber polymers, vulcanizing agents, fillers, anti - aging agents,
processing aids, and diluents. Although processing aids cannot
extend the lifespan of rubber gaskets, they are very effective in
improving the mixing, extrusion, and compression molding properties
during gasket manufacturing. The selection of raw materials and
their ratios will determine the final performance of rubber gasket
materials.
Natural rubber is obtained from the latex of the Hevea brasiliensis
tree, and its basic chemical composition is cis - polyisoprene.
Isoprene rubber is a high - cis synthetic rubber made from
isoprene. Due to its structure and properties being similar to
those of natural rubber, it is also known as synthetic natural
rubber. Styrene - butadiene rubber is copolymerized from butadiene
and styrene, and it is divided into emulsion - polymerized styrene
- butadiene rubber and solution - polymerized styrene - butadiene
rubber according to the production method.
Butadiene rubber is obtained by polymerizing butadiene. Compared
with other general - purpose rubbers, vulcanized butadiene rubber
has particularly excellent cold resistance, wear resistance, and
elasticity. It generates less heat under dynamic load, has good
anti - aging properties, and is easy to be used in combination with
natural rubber, neoprene, nitrile rubber, etc.
