APPARATUS FOR INDIRECT EVAPORATIVE COOLING OF UPFLOWING FLUID BY CONTACT WITH DOWNFLOWING WATER FROM OVERLYING EVAPORATIVE COOLING SECTION

摘要

ABSTRACT OF THE DISCLOSUREA high efficiency, induced draft, combination counter-flow-crossflow fluid cooling apparatus and method is providedwhich gives unexpectedly enhanced cooling of hot fluid by causingthe fluid to pass upwardly through a series of serpentine heatexchange conduits in primarily countercurrent, indirect sensibleheat exchange relationship with external cooling water gravita-ting from an overlying evaporative water cooling section. Cross-flowing air currents are pulled through the apparatus to evapora-tively cool the water not only in the upper cooling section butalso in the sensible heat exchange area as well. Countercurrentflow of coolant water and fluid to be collected ensures that thecoldest water and coldest fluid are in thermal interchange duringthe final stages of fluid cooling at the upper ends of the heatexchange conduits, so that the fluid temperature can approachthat of the cold water as opposed to approaching the temperatureof heated water found adjacent the lower ends of the conduits,which is conventional in cocurrent flow units of this type. Thefluid conduit system is preferably arranged for causing increasedfluid residence time, and thereby greatest temperature differenceand longer heat exchange between the fluid and coolant wateradjacent the air inlet of the apparatus where air and coolantwater temperatures are lowest relative to the fluid to be cooled,so that an ideal countercurrent flow relationship is obtained andmaximum heat transfer is assured. An underlying water collectionbasin is also employed in the apparatus which is constructed topermit collection of cooling water to a level above that of thelowermost portions of the hot fluid conduits, in order to allowthe hot fluid traveling through the conduits to beat the col-lected water to prevent freezing thereof during wintertime oper-ations when the internal water pump is shut down causing thestoppage of all evaporative cooling and hence a raising of thelower water basin level.