Patent attributes
A heat exchange apparatus is provided with an indirect evaporative heat exchange section. The indirect evaporative heat exchange section includes a series of serpentine tubes, and an evaporative liquid is passed downwardly onto the indirect heat exchange section. The evaporative liquid is collected in a sump and then pumped upwardly to be distributed again across the indirect heat exchange section. An improved heat exchange apparatus is provided with an indirect evaporative heat exchange section including a series of serpentine tubes with run sections and return bend sections of both normal and increased height. A secondary spray system or a direct heat exchange section may be provided in the vertical spacing between run section formed by the increased height return bends.