Plate Type Heat Exchanger

Plate Type Heat Exchanger Plate Cooler is a typical heat-exchanger that uses wrinkled-thin metal plates to transfer heat between two fluids. Large commercial version uses gaskets between the metal plates, and this cooler can exchange large amount of heat in short period of time. Since the wrinkled heat transfer plate easily creates turbulence flow at low Reynolds number, the heat transfer co-efficient between two fluids is greater than 2~4 times than typical Tubular type heat-Exchanger, and its counter flow can also increase the heat-exchange rate. Moreover, the Plate Type Heat Exchanger is an ideal heat-exchanger because the temperature approach in a plate cooler may be as low as 1°C whereas tubular type requires an approach of 4°C or more. Therefore, it is enough to cool down main engine, generator engine and other auxiliary machines of the ship.

Working Principle

Gasket is attached to the heat plate which forms flow channel and acts seal up the fluid not to leak to the outside. The number of the heat plate is determined according to the amount of fluid, physical properties of fluid, the pressure drop and thermal condition. The covers prevent the plates bended from the difference of pressure. In the assembly of plate, the surface with gasket is directed to the fixed cover and each plate is hanged in opposite direction alternately. And two fluids cannot be mixed and separated by a thin plate. One fluid always flows in “A” channel and the other fluid always flow in “B” channel.

The Design and Function of Plate Heat Exchanger

The plate heat exchanger consists of a frame, which in turn consists of a Head cover, a Follower cover, a support pillar, a carrying bar, a guiding bar and a number of tightening bolts. In between the head and the follower cover a varying number of pressed plates are clamped together.Each plate is supplied with a gasket, so that the plates form a closed system of parallel flow channels. through which the medias flow alternately at every second interval.

Type of Heat Plate

HIGH -THETA PLATE

• High turbulent flow
• High heat transfer coefficient
• Perfect temperature approach
• High pressure drop

LOW -THETA PLATE

• Low turbulent flow
• Low heat transfer coefficient
• High temperature approach
• Low pressure drop

Plate Design

The construction of the inlet part makes a perfect distribution of the liquids across the heating surface.The inlet part is increased and supplied with grooves preventing “dead spots”which may cause the growth of bacteria or seaweeds in the plate heat exchanger. The inlet with grooves secures a strong inlet part with a minimum of contact points. The inlet parts are constructed with a leakage drained zone fulfilling the 3A specifications.The plate pattern is constructed to obtain a high thermal efficiency. The pattern is available in two designs with different angle sizes giving high respectively low turbulent flow. Combining these in a plate pack and optimal plate composition can be calculated. The angle and fishbone pattern has appeared to male the best heat transmission by a given pressure drop.

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