Evaporative cooler and liquid-gas contact pad therefor

#The present invention pertains generally to evaporative coolers, and more particularly to a new and unique type of evaporative cooler pad which employs ribbons of wood fibers coated with Portland cement.

#Prior art evaporative cooler pads have generally been made of aspen wood excelsior. Aspen wood has a high sugar content, and as a result it supports the growth of bacteria and molds that are carried by the air. Consequently, the cooler pad soon takes on a very objectionable swamp-like odor, and for this reason, aspen excelsior coolers are often termed "Swamp coolers". Another objection to aspen excelsior fiber pads is that they cause the air to become excessively humid, so that although the temperature of the air is reduced, the higher humidity gives it an unpleasant, clammy character. Such excessive humidity is uncomfortable, and the moisture results in rapid rusting of metal objects as well as of warping furniture and other metal structures. Moreover, clothing and bedding tend to become damp and uncomfortable.

#The primary object of the present invention is to provide an evaporative cooler pad which overcomes all of the above-named objections, and which combines high efficiency with relatively low addition of humidity to the air that issues from the cooler.

#FIG. 1 is a sectional view through a typical evaporative cooler, utilizing the pad of the present invention;

#FIG. 2 is an enlarged, fragmentary sectional view through the top edge of the evaporative cooler pad and the water distribution tube directly above it;

#FIG. 3 is an enlarged fragmentary sectional view through the pad, taken at 3--3 in FIG. 1, showing the structure of the same;

#In FIG. 1, an evaporative cooler is designated in its entirety by the reference numeral 10, and comprises a generally box-like, rectangular housing, consisting of a base pan 12 having upturned edges 13 around its outer periphery which form a shallow sump, a top lid 14, and vertical posts 16 connecting the base pan to the top lid. Mounted within the housing is a centrifugal blower 18 driven by an electric motor 20 and belt drive 22. The blower 18 has an intake opening 24, and an exhaust duct 26 extending upwardly through an opening in the top lid.

#Also mounted in the bottom of the housing sump is a submersible pump 28, driven by an electric motor 30, which discharges water upwardly through a vertical pipe 32 to a horizontal distributor pipe 34 having discharge openings 36 in its bottom that allow water to run down onto the top edge of a pad 38 made in accordance with the invention.

#The pad 18 consists of a mat of loosely packed, randomly oriented, ribbon-like strands of wood fiber 40, resembling coarse excelsior. Each of the strands 40 is coated on all sides with a thin, porous, granular skin of Portland cement, which also bonds the strands together wherever they cross one another, forming a rigid, self-supporting structure. The strands of cement-coated wood are spaced apart from one another for the greater part of their respective lengths, forming interstices, or open passageways, through the pad from one side to the other, through which air passes freely. FIGS. 4 and 5, which are greatly magnified views of a single coated strand, show the ribbon-like strand 42 of wood fiber, with its portland cement coating 44.