Plate Type Heat Exchanger
A heat exchanger is a piece of equipment that continually transfers heat from one medium to another in order to carry process energy.
The natural laws of physics always allow the driving energy in a system to flow until equilibrium is reached. As long as there is a temperature difference, heat leaves the hottest fluid and will be transferred to the colder fluid. A heat exchanger is a piece of machinery designed solely for the transfer of heat energy between two mediums, it is therefor necessary that it has large contact surface areas of material separating each medium.
The theory of heat transfer from one media to another, or from one fluid to another, is determined by several basic rules:
About Heat Exchangers
Heat exchangers are devices used to transfer heat from one fluid to another while preventing the two from mixing. Heat exchanger manufacturers can make three main types: shell and tube heat exchangers, air-cooled heat exchangers and plate heat exchangers. Generally, a metal wall partition, acting as a conductor, is between the two fluids. A hot solution flowing on one side of the barrier transfers its heat to a cooler solution flowing on the other side. Thermal energy only flows from the hotter to the cooler in an attempt to reach equilibrium. The surface area of a heat exchanger affects its speed and efficiency: the larger a heat exchanger’s surface area, the faster and more efficient the heat transfer.
About Plate Type Heat Exchangers
Plate Heat Exchangers consist of a number of very thin corrugated heat transfer plates clamped together in a frame. Every second channel is open to the same fluid. Between each pair of plates there is a nitrile rubber gasket, which prevents the fluids from mixing and from leaking to the surroundings. Heat is thus transferred from the warm fluid to the colder fluid via the thin plates. The corrugations support the plates against differential pressure and create a turbulent flow in the channels. In turn, the turbulent flow provides high heat transfer efficiency, making the plate heat exchanger very compact compared with the traditional shell-and-tube heat exchanger. In most cases the plate type heat exchanger is the most efficient heat exchanger. Generally it offers the best solution to heating and cooling applications since it can better handle the widest pressure and temperature limits.
Construction of Heat Exchangers
Heat exchanger manufacturers typically construct their products of steel, titanium, copper, bronze, stainless steel, aluminium or cast iron. One of the biggest problems with heat exchangers is corrosion, which is common due to the constant flowing of liquid. Unfortunately, this is very difficult to avoid. To help prevent this, heat exchanger manufacturers need tubing that is resistant to general corrosion, pitting, stress-corrosion cracking (SCC), selective leaching and oxygen cell attack. Some heat exchanger designs incorporate fins to provide greater thermal conductivity, which also helps.
Most plate type heat exchangers will have titanium plates, titanium is almost totally impervious to corrosion caused by seawater and guarantees a long life providing it is properly maintained.
Shell and tube heat exchangers are constructed from a mixture of copper, nickel, titanium, steel or aluminium depending on there applications. Each part may have different materials depending on what is flowing through it.
Different Applications of Heat Exchangers
Although they are not always known by the name “heat exchanger,” these devices are quite common and aren’t always industrial-types. For instance, a car’s radiator is a useful device for transferring heat from the engine to the air. Other examples of commercial uses for heat exchangers include spa and swimming pool heating, home radiators, hot water radiators, refrigerators and air conditioners. Whether in commercial or industrial use, heat exchangers are vital as energy and money saving devices since most mechanical, chemical and energy systems require heat transferral of some sort.
Custom heat exchangers perform a crucial role in the design, operation and maintenance of heating and air-conditioning systems, vehicle design, power plants, refrigeration, chemical and industrial engineering systems. They are also important in settings such as food processing, industrial engineer processes, pharmaceutical, pulp and paper and the steel industry. All power generation industries need them. Other industries that use heat exchangers include aerospace, chemical, marine, semiconductor, petrochemical, electronic, automotive, water treatment facilities and textiles.