Tags: Dry Cooler

In an air-cooled heat exchanger, or air cooler, heat is transferred from the process fluid to the cooling airstream via extended surfaces or finned tubes. While the performance of wet-cooling systems is dependent on the ambient wet bulb temperature, the performance of air-cooled heat exchangers is determined by the dry bulb temperature of the air....

There are more parameters to be considered in the thermal design of ACHEs than for shell and tube exchangers. ACHEs are subject to wide variety of constantly changing climatic conditions which pose problems of control not encountered with shell and tube exchangers. Designers must achieve an economic balance between the cost of electrical power for...

An ACHE consists of the following components One or more bundles of heat transfer surface. · An air-moving device, such as a fan, blower, or stack. · Unless it is natural draft, a driver and power transmission to mechanically rotate the fan or blower. · A plenum between the bundle or bundles and the air-moving […]

An ACHE is a device for rejecting heat from a fluid directly to ambient air. This is in contrast to rejecting heat to water and then rejecting it to air, as with a shell and tube heat exchanger and a wet cooling tower system.   The obvious advantage of an ACHE is that it does […]

The basic design procedure for air-cooled heat exchangers is similar to that for shell-and tube exchangers. An initial configuration for the unit is obtained using an approximate overall heat-transfer coefficient together with the design guidelines given above. An important preliminary step in the design process is the selection of the outlet air...

Air cooled heat exchangers are commonly used in industrial applications where a reliable source of water is not available as a cooling medium. Even if water is available, in some cases, air cooled exchangers are favored for economic or operational reasons – because dedicated cooling water circuits, pumps, water cooling systems and water...

 Ground space often less than or equal to cooling towers; can also serve dual purpose by mounting air-cooled units above other equipment or on pipe ways or roofs of buildings. Vibration is no problem.

The unit is completely contained in an enclosure equipped with adjustable louvers to control both exhaust and intake air rates. The manual louvers are adjusted seasonally while the automatic louvers are adjusted continuously via pneumatic mechanisms directed by a temperature controller that maintains the temperature of the air entering the tube...

Air-cooled heat exchangers are designed to operate over a wide range of environmental conditions, including ambient temperatures from −600F to 1300F. Special design features are employed for operation in cold climates in order to prevent freezing of the process fluid. If the wall temperature of a tube carrying a hydrocarbon stream reaches the...

Various types of high-fin tubing are available, including: • Integrally finned (K-fin) • Bimetallic (E-fin) • Tension-wound fin (L-fin or I-fin) • Embedded fin (G-fin) • Brazed fin

Common to all air cooled heat exchangers is the tube, through which the process fluid flows.To compensate for the poor heat transfer properties of air, which flows across the outside of the tube, and to reduce the overall dimensions of the heat exchanger, external fins are added to the outside of the tube. A wide […]

The major components of air-cooled heat exchangers include the Overall structural assembly

Advantages of Induced Draft of intake, or about 1500 ft/min. Increased capacity in the event of fan failure, since the natural draft stack effect is much greater with induced draft

For a given mass flow rate of air, induced-draft operation in principle entails greater power consumption than forced-draft operation due to the higher volumetric flow rate of the heated air that is handled by the induced-draft fan. In practice, however, this potential disadvantage tends to be offset by the more uniform flow distribution and lower...

The forced-draft configuration provides the simplest and most convenient fan arrangement. With all blower components located below the tube bundle, they are easily accessible for maintenance and are not exposed to the heated air leaving the unit. However, these exchangers are susceptible to hot air recirculation due to the low velocity of the air...

In an air-cooled heat exchanger, the hot process fluid flows through a bank of finned tubes, and ambient air is blown across the tubes by one or more axial-flow fans. For applications involving only sensible heat transfer, the tubes are oriented horizontally   For condensers, an A-frame configuration (as shown in Figure) is often used,...

Air cooled heat exchangers are used to transfer heat from a process fluid to ambient air. The process fluid is contained within heat conducting tubes. Atmospheric air, which serves as the coolant, is caused to flow perpendicularly across the tubes in order to remove heat. In a typical air-cooled heat exchanger, the ambient air is […]

An air-cooled exchanger (ACHE) is used to cool fluids with ambient air. Air-cooled heat exchangers are second only to shell-and-tube exchangers in frequency of occurrence in chemical and petroleum processing operations. These units are used to cool and/or condense process streams with ambient air as the cooling medium rather than water. Cooling...