US2631021A - Air conditioning unit - Google Patents

Description

March 10, 1953 A W, ARNOLD 2,631,021

AIR CONDITIONING UNITi Filed June 20, 1949 2 SHEETS--SHEET l mmlfmn.

March 10, 1953 A. w. ARNOLD AIR CONDITIONING UNIT 2 SHEETS--SHEET Filed June 20, 1949 ein,

Patented Mar. 10, 1953 AIR CONDITIONING UNIT Albert W. Arnold, Beverly Hills, Calif., assignor to Jabsco Pump Company, Burbank, Calif., a

copartnership Application June 20, 1949, Serial No. 100,221

11 Claims.

This invention relates generally to air conditioning units and particularly to improvements in devices for introducing either cool, moist air or warm, dry air into a room or other living space, such devices being commonly known as evaporative coolers.

Air conditioning units of the type referred to above are usually located outside a building and include a box-like casing having an inlet opening through which fresh air is drawn into the casing by means of a power operated fan or blower unit, the air then being discharged through an outlet opening in the casing from which point the fresh air is directed into the building or a room thereof for breathing purposes. Such air circulating devices are usually equipped with means for moistening and cooling the air, this means consisting of a water-saturable pad which is disposed in the inlet opening and adapted to be saturated by water applied thereto from a suitable source and at a rate commensurate with the rate at which the water is taken up by the air and the cooling and moistening effect necessary to provide comfort for the occupants of the room. It is frequently desirable to operate such an air conditioning unit with dry pads, as when ventilation without cooling best suits the needs of the occupants of the room or other compartment and in this case the supply of water to the pads is diminished or entirely shut off.

In many evaporative coolers water is conveyed to the fibrous saturable pad from a water main in sufficient quantity to thoroughly wet the pad and since muc-h of the Water drips oi from the lower edges of the pad, it is wasted through a drain pipe.

To operate such an air conditioning'k unit in a manner to merely ventilate the room without cooling the same, a hand valve in the water supply line is closed.

Another type of evaporative cooler unit employs a motor driven pump which draws water from a catch pan or reservoir located beneath the pad, the water being supplied to the reservoir from a water main and pumped onto the pad, the surplus water falling back into the reservoir. The supply of water to the reservoir is controlled by a ioat valve in the reservoir, this valve operating to maintain a substantially constant quantity of water in the reservoir. The operation of the electric motor for the pump is controlled from an electric switch disposed at a convenient location. It is common to provide in air conditioning units of the type last discussed a pair of electric motors, one motor driving the fan or blower and. the other motor operating the pump.

Thus, the cost of the unit is high and operational control of the unit is complicated.

It is an object of my invention to obviate the disadvantages of previous air conditioning units of the evaporative cooler type by providing a unit of this character which is extremely simple in construction, economical to manufacture and operate, and which is highly efficient in performing the function of supplying either cool, moist air or warmer, dry air to a room or other compartment.

Another object is to provide a unit of the type referred to which utilizes a pump for pumping water from a reservoir within the casing onto a pad or pads, the pump being driven from theA motor operated fan or blower so that a single motor actuates all the operating parts, this arrangement making for greater simplicity in construction and operation.

Another object is to provide a unit ofthe type indicated which employs a oat type valve for controlling the flow of water from a water main into the reservoir so as to maintain a predetermined, substantially constant quantity of water in the reservoir, the water main or supply line having a manually operable valve by which the iow of water therethrough can be selectively initiated or stopped when it is desired to furnish cool, moist air or warmer, dry air to the room or other compartment.

In previous air conditioning units of this general character closing of the valve in the water supply line merely stops the ow of water from the Water main into the reservoir. Consequently, unless the operation of the pump is promptly arrested, the pump continues to convey the water in the reservoir Lonto the moistening pads until all of the water has been taken up by the air.

It is thus apparent that if the operator inadvertently fails to open the switch of the pump motor circuit, the until will continue to moisten and cool the air until .such time as the water in the reservoir is completely dissipated and the desired change in the humidity and temperature of the air is substantially delayed. It is another object of this invention to eliminate such an undesirable condition by providing control means responsive to reduction in water pressure in the water supply line, when the valve is closed, for inactivating the means for conveying the water from the reservoir to the saturable pads. Specically, this means is responsive to a reduction in pressure of .the

water in the supply line between the manual valve and the float actuated valve, below a predetermined value. By this provision, a slight lowering of the water level in the reservoir, following closing of the supply line valve, causes reduction in water pressure and effects prompt discontinuance of the feeding of water to the pads so that conversion from cool, moist air Ato warmer, dry air is produced without any appreciable time lag.

In accordance with the invention, the object discussed immediately above may be best accomplished by either permitting the pump to remain operative and automatically by-passing the water pumped thereby back into the reservoir, or by discontinuing the operation of the pump by automatically disconnecting the` pump from the motor-driven fan or blower.l In either arrangement, the conveying1 of the water from the reservoir to the pads is promptly arrested in response to a reduction in water pressure in the supply line downstream from the manually operable valve so that the change from cool, moist air to warmer, dry air is effected by the simple act of closing said valve'.

A still further object is to provide pressure relief means associated with the water supply valve and operative automatically when the valve is closed to effect immediate reduction of pressure in the water supply pipe and, consequently, prompt inactivation of the pad wetting means.

Further objects of my invention will become apparent from the following description and from the drawings, which are intended for the purpose of illustration only, and in which:

Fig. 1 is a cross-sectional view through an air conditioning unit constructed in accordance with one embodiment of my invention;

Fig. 2 is an enlarged detail of the float-actuated valve;

Fig. 3 is an enlarged detail of the pressure responsive valve;

Fig. 4 is a cross-sectional View through an air conditioning unit of somewhat modified construction;

Fig. 5 is an enlarged cross-sectional view, taken on` line 5-5 of Fig. 4; and,

Figs. Gand 7 are diagrammatic views of an alternative water supply valve adapted for use in connection with the air conditioning units disclosed in Figs. 1 and 4'.

Referring to the drawings in detail, I illustrate in Figs. 1 to 3,. one preferred embodiment of the invention, the air conditioning unit shown therein being, in eifect, an air duct and including a box-like housing ID having a top wall II, side walls I2, and a bottom wall I3. which has a central depressed portion providing a reservoir I4 adapted to contain Water. Theends of the housing III are left open to provide air inlet' openings I5, and pads I6 of saturable brous material are disposed in these openings so that air entering the housing must pass through the pads. An outlet opening Il is provided in at least one side Wall I2 of the housing through which the air can be discharged from the housing. Secured to the top wall II are trough elements I8 which are adapted to contain water and over a side of which the water can flow down onto the saturable pads I6, the troughs being connected by a water tube I9.

A blower casing 22 is supported by the bottom wall I3 of the housing I0, the casing having air inlet passages 23 in itsl end walls 24. Rotatable in bearing brackets 25 mounted on the end walls 24 is a blower shaft 2S which carries, within the casing, blade elements 2T of a fan or blowerV 28. When the shaft 25 is rotated, the fan 28 functions to draw fresh air from the atmosphere through the pads I6, the air then passing through openings of the casing 22 and discharging through the outlet opening I'I, from which point the air may enter the room or other compartment which is to be air conditioned. The blower unit 28 is driven from an electric motor 30 mounted on the casing 22, the motor shaft carrying a pulley 3I. which drives a larger pulley 32, fast on the blower shaft 26, through the medium of a belt 33.

Water is supplied to the reservoir I4 for moistening purposes through a water supply line 35 which may be connected to a water main, not shown, a manually operable valve 36 in the line 35 being provided for the purpose of establishing flow of. water through the line into the reservoir I4 and shutting off the flow, as desired. The water supply line 35 is connected to a T tting 31 having openings 38 and 39 disposed within the reservoir I4. Assuming for the present that the opening 39- is closed, water flowing upwardly through the supply line 35 discharges through the opening 38 into the reservoir I4 and it is desirable to maintain an adequate quantity ofthe water therein for air moistening purposes. In order to insure a substantially constant supply of water in the reservoir, I prefer to employ a float-actuated valve, indicated generally at 40 in Fig. 1 and shown in detail in Fig. 2. The valve 4i) consists of a float arm 4I which is pivoted at 42 on a suitable bracket 43 and carries a float 44 at one end. At its other end, the oat arm 4I is provided with a conical valve element 45 which is adapted to enter the opening 38v of the T fitting 31' to regulate the rate of flow of Water into the reservoir and to completely shut off the flow when the reservoir contains a predetermined quantity of the water.

It has been indicated that the water in the reservoir I4 is fed upwardly into the troughs I8 from which the water overflows onto the saturable pads I6. The feeding of the water to the troughs is effected by water conveying means which is indicated generally at 49 in Fig. 1 and constructed as next described. A pump 50 is ixedly disposed in the housing I0 and its shaft 5I is axially aligned with and rotated by the blower shaft 26, a suitable coupling 52 connecting the shafts. Thus, the pump is driven continuously from the blower unit 23, as long as the blower unit remains operative. A suction pipe 53 connected to the inlet of the pump 50 extends downwardly into the water within the reservoir I4, and a second pipe 54 connected to the discharge port of the pump extends upwardly and is joined to the tube I9. It is apparent, therefore, that during operation of the pump 50, water is drawn upwardly from the reservoir I4 and' delivered continuously to the troughs I8 so as to cause the pads I6 to be saturated to the degree necessary to moisten and cool the air drawn through the pads and delivered to the room being air conditioned.

As previously explained, it is frequently desirable to circulate air at atmospheric temperature and humidity through the room. In order to discontinue the moistening of the air being forced into the room, the valve 36 may be closed to stop the flow of water into the reservoir I4. It is obvious, however, that since the pump 53 operates continuously, it will function to transfer water from the reservoir to the troughs I8 until the supply in the reservoir is depleted. Consequently, even though the water supply is hut off by the valve 36, the air delivered to the room will continue to be moistened and cooled for a considerable period of time and a quick change in the condition of the air within the :i

f Connected to the discharge pipe 54of the pump 56 is a by-pass line 55 which extends downwardly with its lower open end disposed within the reservoir I4. The bypass line 55 comprises an upper section 56 and a lower section 51, av

by-pass line 55 are connected to the upper cas-v ing section 6I and communicate with the chamber B5. A tube 68 has its upper end screwed into the casing section 62 and is in fluid communication with the lower chamber 66, the lower end of the tube being secured within the opening 39 of the T fitting 31.

During normal operation of the air conditioning apparatus, that is, when the unit is operativeA to moisten and thus cool the air which it delivers to a room or other compartment, the

valve 36 is open to admit water to the reservoir I4. At this time, the water pressure within the upper end of the supply line 35 and the T-l fitting 31 also exists in the tube 58 and .this pressure is sufficient to flex the diaphragm 64 upwardly, as indicated by the broken lines in Fig. 3, so as to close the upper end of the bypass line section 51. Consequently, all the water,v drawn upwardly fromv the reservoir I4 is delivered 1 to the troughs I3 to effect wetting of the pads I 6. *I

When it is desired to introduce air of atmospheric temperature and humidity into the room,l

or other compartment the air conditioning unit is operated with the pads I6 in a dry condition. To effect such a change in the character'of the'k Y introduced air, it is merely necessary to close the water supply valve 36 to stop the fiow of water. At this time water pres'- sure remains in the line 35 downstream from the valve 36 and in the tube 68 so that theby-pas's" line 55 is maintained closed by the pressure-j responsive diaphragm 64 and the pump 50;

into the reservoir I4.

which continues to operate, acts to draw a small quantity of water upwardly from the reservoir.

This immediately causes the float arm 4I 'to pivot, thereby opening the needle valve 38, 45 to relieve the water pressure so that the diaphragm 64 fiexes downwardly to open the by-pass line 55.

Consequently, the water which is drawn from-Y the reservoir by the pump returns thereto by way of the by-pass line and thus is prevented-v from fiowing to the troughs I8. Thus, the pads I6 are permitted to dry out and air which is thereafter drawn through them remains atl at'`"J inospheric temperature and humidity and is merely cleaned by the dry pads which act as lters for this purpose.

When it is again desired to cool the air flowing into the room, the valve 36 is opened to introduce water into the reservoir through the4 needle valve 38, 45 and as the level of the Water rises, the float 44 acts to at least partially close the needle valve, thereby creating water pressure in the fitting 31 'and line 68. This condition results in the exing of the diaphragm 64 upwardly so that the by-pass line 55 is closed and all water drawn upwardly bythe pump 50 is delivered to the troughs I8 for saturating the pads I6.

Referring now -to Figs. 4 and 5, my invention further contemplates a control means 10 which is particularly adapted for use in connection with an air conditioning unit having a pump 1I, the operation of which is stopped when it is desired to operate the unit with dry pads. The alternative control means is shown in connection with a. housing, blower, motor, etc., which are identical with the corresponding components shown in Fig. land therefore designated by the same reference numerals. The pump 1I is supported by and arranged to slide vertically on a guide bracket 12 mounted in the housing I0, the pump being provided with studs 13 which slide in a slot 14 of the bracket (Fig. 5).

In this embodiment of the invention, the pump shaft is offset downwardly from the blower shaft 26 but is driven therefrom by means of pulleys 15 and 16 on the respective blower and pump shaft-s, and a belt 11 encircling the pulleys. By moving the pump 1I downwardly and upwardly, the belt 11 is respectively tightened and loosened to selectively render the pump operative or inoperative. When the pump is driven, it acts to draw water upwardly from the reservoir I4 through a suction pipe 19 vand to pump the water upwardly through a discharge pipe 8G and connecting line I9 into the troughs I8, the pipe 88 having a fiexible section 8|.

Means is provided for automatically shifting the pump 1I in either direction, this means being pressure responsive and including a cylinder element fixed within the housing I0. A piston 88 is slidable in the cylinder element 85 and has a rod extension 81 which is connected to the housing of the pump 1 I.

A coil spring 88, disposed in the cylinder element 85, engages the lower side of the piston 66 and thus normally tends to force the piston 85 andpump 1I upwardly so as to loosen the drive belt 11 suiiiciently to disrupt the operation of vthe pump so that no water will be supplied to the pads I6. However, the upper end of the cylinder is maintained in iiuid communication with the T fitting 31 by means of a pipe 98 so that when the valve 36 is open, as when it is desired to maintain the pads I6 wet to supply cool, moist air to the room, water pressure obtaining in the T fitting 31 is also applied against the upper end of the piston 86 to force the latter downwardly against the action of the spring 88.

It is thus seen that as long as the valve 36 remains open and water is supplied to the reservoir I4, the pump is maintained operative by drawing the pump downwardly to tighten the belt 11, the fiexible portion BI of the pipe 86 permitting such movement of the pump. When it is desired to discontinue the injection of cool, moist air into the room and to supply air of atmospheric temperature and humidity, the water supplyvalve 36 is closed. While sufficient pressure may exist at this time in the tting 31 to maintain the pump 1I operative, this pressure is very soon dissipated due to the fact that the fioatactuated valve 40 opens. When the pressure within the cylinder element 85 is thus relieved, the spring 88 forces the pump 1I upwardly to loosen the belt 11 and disrupt the drive. Thus.' the control means 13 operates in'respo'nse to :duid pressure in the fitting 31, when the Valve 36 is open, to energize the pump 1I so asl to wet the pads I, and functions in response to-a reduction in pressure in the fitting below a predetermined value, as governed by the strength of the spring 8 3, to inactivate the pump to discontinue the wetting of the pads. The control means 18 is in communication with the T tting 31 by means of a pipe St so that when the valve 38 is open, as when it is desired to maintain the pads l5 wet to supply cool, moist air to the room, water pressure obtaining in the T fitting 31 is also applied against the upper endof the piston 86 to force the latter downwardly against the action of the spring 88.

It is thus seen that as long as the valve 36 remains open and water is supplied to the reservoir i4, the pump remains in lowermost position to tighten the belt 11, the iexible portion 8! of the pipe 3S permitting such movement of the pump. When it is desired to discontinue the injection of cool, moist air into the room and to supply air of atmosphericV temperature and humidity, the water supply valve 36 isclosed. While suilicient pressure may existat this time in the fitting 3'! to maintain the pump 1l operative, this pressure is very soon dissipated due to the fact that the neat-actuated valve 40 opens to admit water from the T iitting into the reservoir It. When the pressure Within the cylinder element 85 is thus relieved, the spring S8 forces the pump 1i upwardly to loosen the belt 'il'v and disrupt the drive. Thus, the control means `1t operates in response to fluid pressure in the vfitting 31, when the valve 3G is open, toenergize the pump 1| so as to wet the pads I6, and functions in response to a. reduction in pressure in the liitting below a predetermined value, as governed by the strength of the spring S3, to inactivate the pump todiscontinue the wetting of 'the pads. `The control means 19 is highly sensitive and emcient and by its use the air being introduced into a room or other compartment can be selectively made cool and moist or warmer and relatively dry bylthe simple act of opening and closing the Water supply valve 3G. It has also been shown that the air conditioning unit is further simpliiied in construction and operation by driving both the blower unit and the pump from va single electric motor so that it is unnecessary to inactivate the pump by shutting oii a separate driving motor therefor, as is the case in conventional air conditioning units utilizing water pumps.

Referring now to Figs. 6 and 1, it is within the concept of this invention to providevalve means Q5 for further expediting the reduction in'pressure in the T tting 31 and lines 68=and`9ll so as to promptly render the pad 4wetting lmeans ineffective. The valve means 95 replaces the shuton" valve 3s shown in Figs. 1 ande and is a threeway valve having a casing 96 provided with a bleed port 91, the casing also having a transverse port 88 through which water can flow into the T iitting 31. A valve member 95 rotatable in the casing 9S has a T-shaped passage therein providing a straight transverse port I9@ and a branch port mi. When the valve member 99 is in the position shown in Fig. 6, 'water may flow upwardly through the T iitting 31 into the reservoir i4 and, as previously explained, the pressure of the water in the T fitting and in the lines 68 or 90, as the case may be, to maintain the pad wetting means operative. However, when the valve member 53 is rotated to theposition illustrated in- Fig. 7, the ow-of water to the 'reservoir I4 is shut off and pressure of the water in the upper portion of the pipe 35 and in the lines 68 or 90 is immediately relieved due to the fact that the water in these lines may bleed through the port 91. It is thus seen that when the valve means S5 is operated to shut on? the supply of water to the reservoir, water pressure in the unit is immediately reduced to zero so that inactivation of the pad wetting means is promptly eected and the conversion from cool, moist air to drier air of atmospheric temperature is greatly expedited. f While Amy improved air conditioning unit has been herein disclosed as embodied in several preferred forms of construction, by way of example, it will be apparent to one skilled in the art that various modifications might be made in the structure without departing from the spirit of the invention. Consequently, I do not wish to be limited in this respect, but desire to be aorded the full scope of the appended claims.

I claim as my invention:

l.. An evaporative cooler, comprising: a housing having inlet and outlet openings therein and Walls defining a reservoir for containing water; power operated fan means for drawing air through said inlet opening into said housing and discharging the same through said outlet opening; water saturable material in said inlet opening through which the air passes; a conduit through which the water can flow from said reservoir to said material to saturate the same; a pump for eiecting flow of water through said conduit; a by-pass line connected to said conduit downstream from said pump and adapted to return water from said pump to said reservoir; a pressure water line for supplying water to said reservoir; a manually operable valve in said Water supply line; and a pressureresponsive valve connected in said by-pass line and operatively connected to said water supply line, said pressure-responsive valve being normally maintained closed in response to pressure of predetermined value in said water supply line so as to prevent return flow of Water from said conduit to said reservoir, but adapted to open in response to a reduction in pressure in said supply line below said predetermined value, when said manually operable valve is closed, to allow such return flow` 2. An evaporative cooler as defined in claim 1, including a float-operated valve for controlling the iiow of water from said supply line into said reservoir, the closing of said manually operable valve and the opening of said float-controlled valve causing the reduction in water pressure in said supply line to actuate said pressure-responsive valve.

3. An evaporative cooler as dened in claim 1 in which said pressure-responsive valve includes a housing, a flexible diaphragm within said housing and dividing the interior thereof into a rst chamber and a second chamber. said rst chamber being in iiuid communication with said con-v duit and said reservoir, and said second chamber being in iiuid communication with said water supply line downstream from said manually operable valve. fluid pressure in said supply line and said second chamber causing flexing of said diaphragm in one direction to close said first chamber so as to prevent return iiow of water from said conduit to said reservoir, and reduction in said pressure allowing flexing of said diaphragm in the opposite direction so as to open said rst chamber to allow return ow of the Water to said reservoir.

4. An evaporative cooler as dened in claim 1 in which said power operated fan means drives said pump.

5. An evaporative cooler, comprising: a housing having inlet and outlet openings therein and walls defining a reservoir for containing` water; power operated fan means for drawing air through said inlet opening into said housing and discharging the same through said outlet opening; water saturable material in said inlet opening through which the air passes; a pressure water line for supplying water to said reservoir; a manually operable valve in said water line; a conduit through which the water can iiow from said reservoir to said material to saturate the same; a pump movably mounted in said housing for effecting iiow of water through said conduit, said pump being drivingly connected to said power operated fan means when moved in one direction and disconnected therefrom when moved in the opposite direction; and moving means responsive to water pressure of predetermined value in said supply line for moving said pump in said one direction and to a reduction in said water pressure below said predetermined value for moving said pump in said opposite direction.

6. An evaporative cooler as defined in claim 5 in which said fan means has a rotary shaft and in which said pump has a rotary shaft and is movable toward and away from said fan shaft, and including a pulley on said fan shaft; a pulley on said pump shaft, and a belt surrounding said pulleys by which said pump can be driven, movement of said pump in a direction away from said fan shaft tightening said belt to effect said drive, and movement of said pump toward said fan shaft loosening said belt to distrupt said drive.

7. An evaporative cooler as defined in claim 5 in which said moving means includes a stationary cylinder; a piston slidable in said cylinder and operatively connected to said pump, one end of said cylinder being in fluid communication with said water supply line downstream from said manually operable valve so that one side of said piston is exposed to said water pressure of predetermined value to be forced thereby in a rst direction to eect movement of said pump in said one direction; and a spring disposed within the other end of said cylinder and engaging against the other side of said piston, said spring being operative to move said pump in said opposite direction upon reduction of said water pressure below said predetermined value.

8. An evaporative cooler as defined in claim 5 in which said moving means includes a stationary cylinder; a piston slidable in said cylinder and operatively connected to said pump, one end of said cylinder being in fluid communication with said water supply line downstream from said manually operable valve so that one side of said piston is exposed to said water pressure of predetermined value to be forced thereby in a rst direction to effect movement of said pump in said one direction; and a spring in said cylinder engaging the other side of said piston and operative to force the same in the opposite direction upon reduction of said water pressure below said predetermined value.

9. An evaporative cooler, comprising: a housing having inlet and outlet openings therein and walls defining a reservoir for containing water; power operated fan means for drawing air through said inlet opening into said housing and discharging the same through said outlet opening; water saturable material in said inlet opening through which the air passes; flow inducing means normally operative to effect flow of Water from said reservoir to said material to saturate the same; a pressure water line for supplying Water to said reservoir; a manually operable valve in said water line for controlling the flow of water therethrough; a float-operated valve for controlling the delivery of Water from said line into said reservoir so as to maintain a substantially constant volume of water in said reservoir; control means responsive to reduction in pressure in said water line below a predetermined value, when said manually operable valve is closed, for rendering said Iiow inducing means ineifectual; and pressure relief means operative automatically in response to closing of said manually operable valve to relieve the water pressure in said water line.

10. An evaporative cooler as defined in claim 9 in which said pressure relief means is incorporated in said manually operable valve.

11. An evaporative cooler as defined in claim 9 in which said manually operable valve is of a three-way type, said pressure relief means including a bleed port in said valve.

ALBERT W. ARNOLD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,792,590 Kirk Feb. 17, 1931 1,870,196 Hegan Aug. 2, 1932 1,965,866 Tolman July 10, 1934 2,156,317 Smith et al May 2, 1939 2,201,647 Feinberg May 21, 1940 2,235,116 Ray Mar. 18, 1941 2,237,497 Munford Apr. 8, 1941 2,242,186 Stair May 13, 1941 2,539,344 Carraway Jan. 23, 1951

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