Plate heat exchangers are available in a variety of models. Let’s look at the principal heat exchanger designs:
Brazed Plate Heat Exchangers
Compact and with high power efficiency, brazed plate heat exchangers are a common inclusion in hot water systems, industrial and refrigeration equipment. Brazing is a process like soldering in which two pieces of metal are joined by melting a third metal onto the join and baking this into place. Brazed plate heat exchangers normally feature stainless steel brazed by copper or nickel, making them highly resistant to corrosion.
Brazed plate heat exchangers cannot be opened. Cleaning is conducted by flushing the device with a suitable cleaning agent.
Gasketed Plate Heat Exchanger
Gasketed plate heat exchangers feature rubber gaskets between the transfer plates. These create watertight seals and control flow rates. These larger, higher capacity models are standard equipment in food and drink production and heating, process engineering and HVAC systems.
The gasket seals mean that these devices are easy to disassemble for maintenance and cleaning. Additional plates can also be added to increase the capacity and thermal flow of the device.
Plate-Fin Heat Exchanger
Plate-fin heat exchangers feature finned chambers alongside the heat transfer plates, the latter typically made from aluminium. These models are usually more compact than other plate heat exchangers but still offer a large heat transfer surface area.
Plate fin heat exchangers, also known as plate-fin and tube exchangers, are favoured in industries that require lightweight heat transfer equipment. Examples include aerospace, vehicle engineering and cryogenic chemical processing.
Welded Plate Heat Exchanger
Welded plate and frame heat exchangers feature plates that have been welded together into a single block. This makes maintenance more difficult and means that the capacity of the devices is fixed because additional transfer plates cannot be added. However, it also makes welded plate heat exchangers highly durable - they can withstand corrosive fluids, high temperatures, and pressures. As a result, they are widely used in heavy industry - you will find them in oil refineries, gas extraction plants, power stations and similar locations.
Semi-welded plate heat exchangers are a variant model, combining welded and gasketed plates. Welded plate sets are connected via gaskets to other sets. Therefore, the fluid channels through this device alternate between gasketed and welded seals. This allows hot fluid and corrosive liquids to be directed to one side while servicing is conducted on the other.