US2886957A - Evaporative air coolers - Google Patents

Description

S. A. KESSE LMAN "EVAPORATIVE AIR COOLERS May 19, 1959 2 sheets-sheet 1 Filed May 18, 1955 INVENTOR. SAMUEL A. M'ssELm/v JTTORINEY y 19, 1959 s. A. KESSELMAN 2,886,957

EVAPORATIVE AIR COOLERS Filed May 18, 1955 2 Sheets-Sheet 2 all A\\\\\\\ JAM/1 A. Kass/IL MAN 11 TTOR NE J United. States Patent EVAPORATIVE AIR COOLERS Samuel A. Kes selman, Lanrelton, N.Y.

Application May 18, 1955, Serial No. 509,253

1 Claim. c1. 62-314) This invention relates to air cooling devices and more particularly to those of the type which depend upon the evaporation of water for their effectiveness.

In air coolers of the evaporativetype it is not unusual to pass a stream of warm dry air through a shower of cool water. In this manner, a portion of the water is evaporated by the passage of the warm air circulating through the water shower, the air giving up some of its heat to the water. Quite naturally, heat is transferred during this evaporative process from the air to the cooler water which is then partially vaporized, thus lowering the temperature of the air stream, which can then be directed to an area to be cooled. While this system of cooling is advantageous over a conventional refrigerative or air conditioning system from an economical standpoint, it is not without its disadvantages. Perhaps the most serious drawback is that of carrying the evaporated water or water vapor into the area to be cooled by the stream of cooled air, thereby raising the humidity of the area and in effect nullifying, or at least decreasing, the natural cooling which people experience through the evaporation of perspiration from their bodies.

It is to overcome this prime disadvantage of the referred to type of air cooling system that thepresent invention is provided. In doing so, however, it is intended that an economical, non-complicated, and reliable apparatus be used in achieving the desired result. It therefore becomes the object of this invention, to provide an economical, simple, and reliable apparatus for cooling air, which apparatus will be effective without resort to refrigeration methods and without raising the moisture content of the cooled air.

In carrying out this invention there is provided two adjoining air chambers separated by a bafile or partition of heat conductive material, one side of which is coated with a water absorptive or retaining material which in turn is maintained in a moistened condition. There is further provided means for first directing a stream of air against the moistened material and thereafter exhausting this air to the outside atmosphere. A second stream of air is then directed against the remote side of the bafile which has been cooled by the first stream of air playing on the moisturized coating to thereby cool the air which can thereupon be directed to an area to be cooled.

Features and advantages of this invention can be gained from the foregoing and the description of several embodiments of the invention which follows.

In the drawings:

Figure 1 is a perspective view of an enclosure particularly suitable for one embodiment of this invention, showing the louvres and ports for directing air how to and from the cooling apparatus;

Figure 2 is a view taken along line 2-2 of Figure 1 schematically showing the apparatus for carrying out this invention;

Figure 3 is a schematic view in perspective omitting the apparatus enclosure but showing another embodiment of the present invention;

Figure 4 is an elevational view taken along line 4-4 of Figure 3 showing particularly the configuration of the cooling bafiie.

Referring to Figure 1, there is shown an enclosure 10 having a pair of fan openings 11 and 12 disposed on opposite sides thereof. On the other two sides of the enclosure there are found a series of louvres 13 and 14, while on the top surface of enclosure 10 there are louvres 15. As will hereinafter be seen, a first stream of air will enter through opening 11 and exhaust through louvres 15 whereas a second stream of air will enter through louvres 13 and 14, and exit through opening 12. An interior bafiie or partition is utilized to keep the two re ferred to air streams from intermixing.

In Figure 2, the internal structure of the cooling apparatus as well as the components used therein are sche/ matically shown. A baffle or partition 16 extending arcuately from one side of the enclosure 10 to the other and between the top and bottom surfaces thereof divides the interior of the enclosure into two plenums or air chambers which will be designated 17 and 18. Plenum 17 is formed to channel or direct the air stream entering opening 11 and leaving through louvres 15.. Plenum 18 is similarly formed for the air stream entering louvres 13, 14 and leaving through opening 12. The baflie itself is formed of a heat transmissive material of high conductivity such as aluminumor copper to one side of which is adhered a layer 21 of any suitable moisture retaining material. As shown, the moisture retaining layer 21 makes up one side of air chamber 17.

An electric motor 22, suitably mounted in air chamber 17, is provided with a transverse shaft 23 which extends in one direction to port or opening 11 where it supports an intake fan 24 and in the other direction, through batfie 16 to port or opening 12 where it supports an exhaust fan Operation of the motor causes air to be drawn through port 11, by fanf24fiwhereupon it impinges against the moistened material 21 and is thereafter exhausted through louvres 15 to the outside atmosphere. It. will be noted here that material layer 21 is maintained in a moistened condition by any conventional means which may take the form of spraying the surface of the material with water from arcuate shaped spraying device 19 until it becomes saturated or splashing water from a pan (not shown) by impellers mounted on the tips of the fan blades. At the same time that air is being forced through air chamber 17, exhaust fan 25 is drawing air through louvres 13, 14, against the metallic surface of bafile 16, and thereafter directing it through port 12 to the area to be cooled.

It is clear that the air stream which, in being directed through air chamber 17, impinges on the moistened material 21 on one side of baflie 16 is etfective to increase vaporization or evaporation of water therefrom thereby lowering the temperature of the baffle 16. Theoretically the baflie temperature can be lowered from its ambient value to its wet bulb value, although in practice it is unlikely that a sufficient draft of air will be directed against the moistened material to evaporate enough water to achieve this result. The consequence of lowering the bafile temperature is that the air drawn into air chamber 18 through louvres 13, 14 strikes the cool metallic plate and is itself cooled, the heat being conducted through the baffie due to the temperature differential existing between its two surfaces. It is now apparent that the batfle is arcuately extended between the side walls of the enclosure in order that the largest possible cooling area be obtained.

In Figure 3 a modified form of my invention is shown in which the baflle plate 30 is horizontally disposed and corrugated. The folds of the bafiie are spaced apart near the inlet wall 28 of the unit, but the valleys thereof are closed at their terminus as by bringing the walls of the corrugations into contact with each other. (Figure 5.) The under sides or tunnels of the corrugations, on the other hand, remain separated so that unobstructed passageways extend from the inlet opening 31 in wall 28 to the outlet openings 29 in the remote end wall 32 of the unit. I

In the modification of the unit now being described, the upper surface of the battle carries the moisture retaining material 33. A pump 34 driven by electric motor 35 is shown for bringing water from reservoir 36 through conduit 37 to the spraying device 40 which serves to distribute the Water over material 33 and maintain it in a saturated state. However, any means found suitable for maintaining material 33 in a moistened state may be utilized.

In the present embodiment, an electric motor 41 drives intake fan 42 to bring air to be cooled into the cooling unit. As shown, though, a single fan will now suffice for the entire apparatus inasmuch as the air drawn into the unit will now be divided by the leading edge of the horizontally disposed baffle plate into two currents. One of these air currents Will pass over the corrugated baffle plate to evaporate the water held by the moisture retaining material 33 and carry the water vapor to the outside atmosphere through louvres 43 in the top 44 of enclosure 45. The temperature of the baflie plate will thereby be lowered from its ambient value to a value approaching its wet bulb value. The second current of air will contact the cooled under-surface of the baffie 30 and thereby be cooled after which it will be directed through the passageways in end wall 32 to the area to be cooled.

While my invention has been disclosed as a single unit apparatus, it is to be understood that a multiplicity of units can be concatenated so that the air which is finally directed to the area to be cooled is at a temperature arrived at by cooling in several stages or steps, each of which successively lowers the temperature of the cooled air. For example, the cooled air produced by a first unit is directed to a second unit where it is cooled to a lower temperature.

Inasmuch as many apparently difiering variations or embodiments can be made of this invention without departing from the spirit and scope thereof, it is intended that the specification and drawings be interpreted as illustrative and not in a limiting sense.

What is claimed is:

An evaporative air cooling apparatus comprising in combination an enclosure including end walls and a top, a horizontally disposed heat exchanger element having a plurality of alternate ridges and grooves extending longitudinally within said enclosure, said element being formed of a single sheet of heat conducting material that is corrugated to provide the aforesaid ridges and grooves and the upper side of which is provided with a moisture retaining material, one end wall of the enclosure intersecting one end of said element transversely with respect to said ridges and grooves and having openings therein corresponding to the ridges of said element so that passageways formed by the underside of the ridges extend out of the enclosure, water spray means for directing Water to the coated side of said element to maintain it in a moistened condition, and a single fan disposed adjacent to the other end of said corrugated heat exchanger element for drawing air through theother end Wall of said enclosure and directing the air drawn into the enclosure against the edge of said element transverse of the ridges and grooves whereby the air is divided into two currents, one of which passes over the moisture retaining material on the upper side of said element and is exhausted through louvres formed in the top of said enclosure and the other of which passes through the passageways formed by the ridges of said element and out through the openings formed in said one end wall of the enclosure to the area to be cooled.

References Cited in the file of this patent UNITED STATES PATENTS 2,023,876 Dubrovin Dec. 10, 1935 2,107,280 Ballard Feb. 8, 1938 2,150,514 McInnerny Mar. 14, 1939 2,157,531 Fisher May 9, 1939 2,425,417 Booth Aug. 12, 1947

Images