Abstract: The invention relates to spray booths intended for spraying or painting of articles and designed to be passed by a stream of atmospheric air admitted through inlet ducts and exhausted through outlet ducts and therebetween forced through a water curtain formed inside the spray booth for separating off paint particles remaining in turbulent movement in the air after ejection from a spray gun operating in the interior of said spray booth. To improve economy in the operation of the spray booth it is desirable to bring about heat exchange between the exhaust air and the incoming atmospheric air. However, due to excessive cooling of the exhaust air with its high moisture content and low temperature after passage through the water curtain by the heat exchange with the admitted atmospheric air of low temperature especially during the cooled season there is a great risk of ice precipitation in, and clogging of, the air passageways in the exchanger.

Abstract: Method and device for defrosting or deicing heat exchangers of the type in which a stream of warm, moist gas, such as warm, used ventilating air--so-called exhaust air--exchanges heat with a cooler medium, such as incoming fresh air, in a contact apparatus, and in which the two media flow through a large number of parallel layers separated from each other by thin walls.

Abstract: The invention relates to a method and a device for preventing formation of mist by the discharge of moistened air from an evaporative cooler, primarily a cooling tower of the multi-layer type, comprising a contact body composed of a plurality of layers forming between themselves gaps passed by water to be cooled and atmospheric air which is moistened and heated by contact with the water in counter-current or cross-current flow. Under certain conditions as when the temperature of the atmospheric air is so low, when the moistened and heated air is discharged to the atmosphere and cooled to the low temperature of the latter, the moisture contained in the discharged air will be condensed and precipitated in the form of mist to the extent it exceeds the saturation point of the air. Such precipitation can be avoided by mixing the moistened air prior to its escape into the atmosphere with preheated dry air.