US2587130A - Zoned evaporator mat for air coolers - Google Patents

Description

Feb. 26,1952 A. s. FEINBERG ZONED EVAPORATOR MAT FOR AIR COOLERS Filed Nov. 5. 1947 2 SHEETS-SHEET 1 Arc/lie 5. Fe/flberg INVENTOR.

A T ToIeNEr 2 SHEETSSHEET 2 Feb. 26, 1952 A. s. FEINBERG ZONED EVAPORATOR MAT FOR AIR COOLERS Filed NOV. 5, 1947 Patented Feb. 26,1952

UNITED STATES PATENT OFFICE.

'ZONED EVAPORATOR MAT FOR AIR 1 COOLERS ArchieS. Feinberg, Dallas, Tex.

Application November 5, 1947, Serial No. 784,181

4. Claims. 1

This invention relates to air coolers-of the evaporative type and it has more particular reference to improvements in such devices calculated to render them effective in regions where they are not practical as now generally constructed.

The principal object of the invention is to widen the territorial scope of usage of the evaporative type of coolers by reducing the dampness associated with their functioning .under various climatic conditions and thus make feasible their successful operation in regions where their use is now considered unsatisfactory and also, to improve the performance of the evaporative cooler in those hotter and more arid regions, during certain periods, where it is now in wide and successful use.

Another object of the inventionis to provide an apparatus and method providing zoned evaporation to eliminate objectionable characteristics of evaporative coolers in more temperate, semi-humid regions, and to make feasible evaporative cooler use in such regions by :attuning its vaporization to the balanced atmospheric laws of nature which aflect moisture evaporation outof-doors, and the inverse temperature and humidity action which attends such evaporation. By permitting only prejudged and varying amounts of heat transfer vaporization under variable outdoor temperature, moisture vapor and .latent heat conditions, definite .protection against .baflles to increase or decrease the degree of saturation of the mat.

To explain the manner in which these improvements apply, it is first necessary to review the mode of functioning of the conventional evaporative cooler, its advantages and shortcomings and particularly, the importance of territorial and climatic application to itsoperation. 1

Water alone is the temperature reducing medium of the evaporative cooler. It employs no ice or refrigeration chemical. The success or failure of its operation depends upon the quantity of moisture it is able to evaporate without causing too high a relative humidity in the airit condi- 2 tlons. Thus, its performance is directly related to, and controlled by, the type of climate in which it functions. The prevailing dry bulb (Fahrenheit) thermometer temperature, the wet bulb temperature, the relative humidity that exists and the ability of the air to absorb moisture are the determining factors of its effectiveness as a comfort creating agent. Because of the ability of air toapproximately double its water vapor carrying capacity with every 20 increase in temperature, the evaporative. cooler functions best in those areas where the temperatures are the highest and the air the driest, and functioning without dampness objections. (Air atfi0 Fahrenheit contains 10.9 grains of moisture per cubic'foot when totally saturated whereas its total saturation'capacity at 100 is 19.7 grains.)

, The evaporative cooler extracts no heat from the air. Its function is one of heat transfer wherein the temperature reduction which regisration and in this instance, a portion of the air's 1 sensible heat supports the vaporization occurring within the cooler. This vaporization converts such sensible heat as is used in the process into latent heat, 1. e., latent heat of vaporization. Be-

cause sensible heat alone registers on an ordinary Fahrenheit-dry bulb thermometer, the sum total of the sensible heat so converted thus appears on the thermometer as a reduction in temperature. The wet bulb thermometer, which registers the sum total of the air heat content, both'sensible and latent, is not lowered during the process. Sensible heat loss must inevitably result in equivalent latent heat gain and this forms much of the basis for the high humidity, dampness complaints associated with evaporative cooler functioning.

The evaporative cooler, unlike refrigeration, cannot remove moisturefrom air. Instead, moisture absorbed by the air passing through the moistened pads or spray of the cooler adds to the airs humidity and this. cou led with a. reduced dry bulb temperature, the wet bulb remaining stationary, accounts for considerable increase in both relative humidity andlatent heat in the conditioned. air. Dampness resulting from such functioning greatly restricts its use to hot. dry sections of the country Where it is not stigma tized as wet'air conditioning, Its performance in these arid regions is insured against dampness by the hot temperatures which exist. For example, a typical day of 106 F. with a wet bulb of 68 will result with a conventional cooler in a conditioned air temperature of '7'7 /2 Fahrenheit (dry bulb), a wet bulb temperature of 68 and a not perceptibly high relative humidity of fil (The foregoing calculations are made on the basis of customary evaporative cooler functioning of 75 percent cooling of the wet bulb depression" efficiency.) (Wet bulb depression is a term used in the air conditioning industry to denote difference in degrees between the airs dry bulb and wet bulb temperatures.)

4 of moisture to be entrained in or absorbed by the air passing through the mat in accordance with varying outside temperatures.

To accomplish this, the invention provides an assembly of vertical, overlapping bafiles 23 which are adapted, in closed position, to isolate the zone B from the zone A and similarly, a second assembly of baffles 24 which isolate the zone C from zone A. Actually, these baffles restrict the water discharge of the hydro-spray l8 by closing off one or both of the zones B or C in the manner In the semi-humid, more temperate northern,

much moisture at these lower temperatures; thus,

its use in these areas on other than abnormally hot days results in atmospheres too high in humidity with resultant dampness menacing to merchandise, furniture, fixtures, etc.

With the foregoing objects in view, the invention has further reference to certain features of accomplishment which will become apparent as the description proceeds, taken in connection with the accompanying drawings wherein:

Figure 1 is a side elevational view of an evaporative cooling unit constructed according to the present invention shown as being installed on a building roof with provisions for thermostatic control out of the influence of reflected heat.

Figure 2 is a view on a larger scale showing the evaporative cooling unit in vertical section.

Figure 3 is a view in transverse section, taken on line 3--3 of Figure 2.

Figure 4 is raj-fragmentary perspective view of a bafile assembly showing the operating means therefor, and v Figure 5 is a suggested wiring diagram.

Continuing with a more detailed description of the drawing, reference numeral l denotes a cabinet which is arranged in a manner best suited to the air intake of an enclosure or building to be cooled, usually on the top of the building, as exemplified in Figure 1 in which ll indicates the roof and i2, the cornice of the building.

Within the front portion of the cabinet I0 is arranged a blower casing l3 containing a blower [4 which is driven by a motor l through the medium of a belt 16. Within the rear portion of the cabinet in is mounted a filter mat ll of fibrous material, such as wood shavings, which is preferably partitioned into vertical sections A, Band C (Fig. 3) which are herein referred to as zones.

At the approximate midsection of the mat or zone A is mounted a disc [8, known as a hydro-spray and this disc is rotated rapidly by a small motor [9 mounted on theopposite side of the mat H. A water pump is submerged in the water of a basin 2| in the bottom of the cabinet and functions to convey water through a line 22 and project the same onto the face of the hydro-spray I9. Water impinging the disc I8 is radially discharged thereby in a sheet spray which latter is influenced in the direction of the mat I! by the suction of the blower i4.

The elements described in the foregoing are not herein considered new, these being present in the conventional evaporative cooler. However, as far as is known, there is no provision made in the conventional cooler for wetting predeteimined areas of the mat to vary the amount to be presently described when outside temperatures require. The central section of the mat or zone A is always exposed to the discharge of the spray l8 since it would be seldom if at any time the unit is operated without moisture. To insure against capillary attraction tending to influence moisture from one to another of the mat zones, a separator or partition 25 is interposed between the sections defined as zones.

The baffles 23 are identical to bafiles 24 and each consists of an elongated, vertical plate pivoted at a and b at its top and bottom respectively (Fig. 2). To the upper pivot a of each bafiie plate is connected the end of an arm 25 and the opposite ends of these arms are pivoted to a link 21. At the midsection of this link is a pair of ears 28 (Fig. 4) and to these ears is connected a slotted crank 29, the latter being mounted on the armature shaft 33 of a small motor, mounted in a housing 3 i. The motor for operating bafiles is of conventional manufacture, is geared to slow speed and its shaft 30 oscillates through an arc of approximately to open and close the baiiles 23 or 24.

The baflies 23 and 24' are each provided with an offset lip 32 along one edge which is adapted to overlap the edge of an adjacent bafiie to afford a positive seal against passage of water therebetween.

When an evaporative cooler is mounted on the roof of a building the reflected heat adjacent the unit is usually of a temperature much in excess of the mean atmospheric temperature. Accordingly, in order that the zones 0 and B may function in keeping with variations in actual atmospheric temperature, thermostats 33 and 34 are suspended over the side of the building and are preset to operate the motors which actuate the baffles 23 and 24 respectively. This is borne out in the writing diagram disclosed in Figure 5-.

It is at once apparent that at comparatively low temperatures and during periods of relatively high humidity, it is desirable in the interest of comfort to reduce the saturated area of the mat H to the minimum of one zone, 1. e., zone A. As the temperature rises, thethermostat 33, preset to close the circuit to the motor which actuates the bafile assembly 23, functions to open these bafiles, and exposes zone B to the discharge of the hydro-spray 18. At still higher temperatures, thermostat 34 will be actuated to close the circuit to the motor which operates the bafile assembly 24-, thereby exposing zone C to the discharge of spray l8. Thus the maximum area of the mat li become saturated.

It is obvious that when only zone A, or zones A and B, are wetted, the reduction in vaporization will not depress the Fahrenheit thermometer te1 n perature to as low a degree as when full-evaporationis. permitted. .This does not appreciably affect interior comfort, being compensated for by the greater moisture deficiency of the conditioned air. A higher rate of evaporation and body heat lossfrom skins of room occupants results in effective temperatures but little at variance with 5 those under the more humid atmospheres produced by full evaporation. tures," as charted in the American Society of Heating. and Ventilating Engineers guide reflect the cumulative comfort quality of temperature, humidity and air motion taken together, which influence the transference of body heat and de- (Effective tempera- 6 which air is influenced by said blower, means disposed centrally of said mat for sprayingwater against the entire area of said mat, a plurality of groups of baffles adjacent said mat, each group comprising a series of vertically disposed plates pivoted for common movement to a position to shield a predetermined portion of said mat area termine the feeling of warmth. Such research 7 has shown that dry air at a relatively high temperature may feel cooler than air of considerably 5 lower temperature with a high moisture content.)

When outdoor temperatures reach 92 degrees Fahrenheit and over, with full evaporation from all zones functioning, moisture saturation capacity of the air at these temperatures in such as toafford protection against dampness thru over-humidification when passed thru the evaporative cooler. Unnecessary on these hotter days, zoned evaporation is needed during the great majority of more temperate summer season days which prevail in these regions, when, without sacrifice of comfort cooling results, protection against dampness is desired.

Manifestly, the construction as shown and described is capable of some modification and such modification as may be construed to fallv within the scope and meanin of the appended claims'is also considered to be within th spirit and intent of the invention.

What is claimed is:

1. An evaporative cooling apparatus including a cabinet having an open rear, a blower in said cabinet provided with an air inlet and an air discharge opening at the front of-said cabinet, a filter mat divided into a plurality of independent sections through which air is drawn by" said blower, a water spraying device adapted to saturate the entire area of said filter mat, a

plurality of groups of vertically disposed battles,

in the rear of said cabinet for isolating preselected areas of said mat into separate zones;

said groups of baflles each comprising a series of plates pivoted for common movement to a position to shield a preselected area of said mat against saturation by said spraying device, and. thermostatically actuated means for moving the plates of said groups of baifles to expose said zones to the saturating action of said spray in accord;

ance with variations in atmospheric temperature,

2. In an evaporative cooler, a cabinet having a blower therein provided with an air inlet and an air outlet for discharging air at the front of said cabinet, a. filter mat for said air inlet through from the product of said water spraying means, and thermostatically controlled means for effecting common pivotal displacement of the baffles of each group to increase and decrease that portion of said mat exposed to said water spraying means in accordance with variations in atmospheric temperature.

3. In an evaporative cooler, a filter mat in vertical, horizontally aligned sections, a blower for influencing air through said mat sections and for discharging the air drawn thereby, means for wetting all of said mat sections simultaneously,

a series of groups of baffles disposed adjacent said filter mat, each of said groups comprising a series of plates pivoted for common movement effective to positively open and close said mat'sections to said wetting means and thermostatically actuated means for operating said bafiles upon changes in atmospheric temperature.

4. In an evaporative cooler, a filter mat divided into a plurality of separate sections in the same plane, blower means for drawing air through said filter mat, a water spraying means capable of. sat- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,791,751 Chester Feb-10,1931 1,878,618 Baker Sept. 20,1932 2,124,290 Fleisher July 19, 1938 2,428,842 Feinberg Oct. 14, 1947

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