Heat Transfer in an Air Dryer
An Air Dryer uses two methods to transfer heat from hot air to cold air: an air-to-air heat exchanger and a refrigeration cycle. The former increases the efficiency of the dryer by reducing the cooling load during the refrigeration cycle. The latter reduces the relative humidity of the outgoing cooled air. These two methods are the most common and efficient. However, there are some limitations to these methods. For instance, the heat transferred from hot to cold reaches a lower temperature than that transferred in a traditional system.
The air-dryer step involves cooling incoming ambient air stream. The airstream is passed over the exterior surface of the heat-transfer elements. The interior surface is cool, while a recirculating intermediate fluid flows through the inside. The condensed water from the incoming air stream is removed from the cooled air stream and passes into an induced draft ambient air vaporizer. This enables the resulting 73deg F. air to be vaporized.
The incoming ambient air stream is cooled by a process known as the air dryer. The air stream passes over the exterior surface of the heat transfer elements while a recirculating intermediate fluid is allowed to circulate within the inner surface. The condensed water from the incoming ambient flow is removed from the air stream and is then drained before entering the induced draft ambient-air vaporizer. The vaporized gas is then recirculated through the system.
The second step is to recover energy from the incoming ambient air stream. This process involves transferring heat from the air to a recirculating intermediate fluid. Indirect expansion of fluid is the fastest method of transfer heat. Indirect expansion of air is the best method. This method is commonly used in cooling towers. For this reason, direct expansion is considered the best method of heat transfer. There are many advantages to using an air dryer.
Intake air is cooled to below freezing in an air dryer. This process combines mechanical and thermal drying processes. Indirectly, the resulting temperature is 73deg F. The incoming air is then cooled to 37deg F. The condensed water is drained from the air stream before entering the induced draft ambient-air vaporizer. The process is done in the same manner for condensed water.
A combination of external and internal components is used for an air dryer. An external heat transfer surface is used for air conditioning. A thermodynamic heat exchange unit is designed to move hot air to cold water. The interior is designed to reduce the temperature of ambient air. The recirculating fluid is the primary heat exchange medium in an air dryer. During the heating process, the external heat-transfer element cools the ambient-air. The resulting stream is then heated to approximately the same temperature.
