摘要 |
<p>A counter flow indirect evaporative heat exchanger (10) having vertically stacked alternate counter flow wet (14) and dry (12) passages where the wet passages are wetted during operation of the heat exchanger by wetting means (50, 52, 53, 54, 70, 72, 74, 76) travelling vertically of the stack. Elongately wetting of a small plurality of the total number of passages (14, 12) of the heat exchanger (10) occurs at a time during vertical travel of the wetting means.</p> |