Evaporative cooler apparatus

An improved portable evaporative cooler utilizes a motor-driven rotatable impeller assembly comprising an evaporator pad mounted on a support as the sole means for driving air to be cooled through the apparatus.

BACKGROUND OF THE INVENTION 
This invention relates to evaporative coolers and more particularly to 
portable coolers designed for use in a motor vehicle, travel trailer or 
other movable structures. Heretofore most portable evaporative coolers 
have consisted of a housing enclosing a water sump, evaporative pads 
contained in respective pad frames upstanding from the sump and a spreader 
above the evaporative pads arranged to distribute water over the upper 
edges of the pads to percolate downwardly and return to the sump for 
recirculation. At the same time air is drawn inwardly through the wetted 
evaporative pads by a blower, evaporating some of the water and cooling 
the air which is blown outwardly from the cooler. 
Evaporative coolers of this type that are mounted inside the space to b 
cooled have not provided for outside, non-saturated air, for the intake 
side of the evaporator pads thereby increasing the humidity of the space 
to the point of saturation and preventing continued evaporation and 
cooling by the apparatus. Moreover, such coolers are unable to prevent 
water contained in the sump from spilling or splashing out through the 
evaporative pads when the vehicle is in motion or in an unlevel position. 
SUMMARY OF THE INVENTION 
The apparatus of the invention comprises a case or housing of a generally 
rectangular configuration with a locking handle for easy portability, an 
attached air duct for delivering dry air to the apparatus from outside the 
space to be cooled, an evaporator impeller consisting of an evaporative 
pad held in cylindrical shape by framework and rotated by an attached 
electric motor to provide air movement through the apparatus and a water 
pump to deliver water from the lower level of the enclosure to a nozzle 
for injecting water, in the form of a fine spray, into the air intake side 
of the evaporator impeller. The impeller is enclosed by a shroud which 
directs the cooled and filtered air to an outlet and directly into the 
space to be cooled. The impeller, shroud combination produces roughly the 
same air flow as a similar sized centrifugal, or radial blower. A 
significant advantage of the cooler of this invention over prior art 
coolers is in not requiring a separate fan for moving air into and out of 
the apparatus. Instead, the evaporator impeller provides the single means 
for moving the air into and through the cooler, thereby reducing weight 
and costs of this apparatus. 
Such an apparatus is inexpensive, lightweight, compact and easily portable, 
completely self-contained and of a simple and rugged construction 
especially suitable for use inside moving vehicles and portable 
structures. The cooler provides less expensive, non-polluting alternatives 
to refrigerated cooling especially in large commercial trucks and heavy 
equipment used for local transportation and construction. The apparatus of 
the invention may also be used for boats and other recreational vehicles 
having easy access to water but with a limited power supply. 
These as well as other advantages will be evident from the following 
detailed description.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
As shown in FIG. 1, an enclosure for a portable evaporative cooler 58 
includes a housing 44 preferably having a flat base and upstanding side 
walls which, when viewed from the front, is generally of a rectangular or 
square configuration. The housing 44 includes a water fill port 33 located 
slightly above the internal, full, water level. The housing also includes 
an opening for attachment of an electric power line 26 which has an 
electric cigar lighter connector attached 56. A cover 6 is attached and 
locked to the housing 44 by locking handle 50 designed to lock the cover 
in place from either the upright or lowered position. Cover 6 includes a 
louvered air outlet nozzle 54 and attached air inlet duct 5 with an 
opening for mounting the duct. Observing also FIG. 3, housing 44 includes 
switches 46 and 48 mounted on the upper front. 
As shown in FIG. 2, aligned with and directly below air inlet duct 5 is air 
inlet port 11 of shroud 17. Flange 8 is attached to the upper side of 
shroud 17 to enclose and reduce the circumference of the inlet side of 
port 11. Impeller pad 10, consisting of a porous and flexible evaporative 
material, is designed to enclose impeller frame 12. With pad 10 covering 
frame 12 the impeller assembly 10/12 is attached to the drive shaft of 
electric motor 20 with washer 16 providing separation and held secure by 
retaining nut 15. Electric motor 20 is attached to the lower side of 
shroud 17 by mounting flange 18 which mates with the lower side of shroud 
17 to form an air tight seal. A air/water separator 14 comprises a lip 57 
projecting toward and slightly below the floor or lower side of the outlet 
of shroud 17. The above-mentioned shroud assembly is enclosed by liner 
insert 24 and includes electric power lead 22 attached to electric motor 
20, an electric power lead 30 connected to water pump 34 enclosed in a 
cavity 42 and connected to water spray nozzle 43 by connecting water line 
40. Water inlet line 38 is attached to water pump 34 and penetrates liner 
insert 24 at the lower level of the upright wall separating the interior 
of the liner insert 24 from the water pump cavity 42. A water inlet filter 
36 is attached to the water line 38. An aperture 32 in the upright wall of 
liner insert is provided to mate with, pull out, water fill port 33 (see 
FIG. 3). 
The outer housing 44 and cover 6 are preferably of the same design and 
construction of a common portable ice chest and provide an enclosure for 
liner 24 and mounting surface for electrical switches 46 and 48. Water 
fill port 33 provides for filling water sump in line 24 to a level 
slightly below the bottom of shroud insert 17. Air inlet duct 5 is 
attached to cover 6 and provides a conduit for the delivery of air from 
outside the space to be cooled through the cover 6, flange 8 and into air 
inlet port 11. The air is forced through impeller pad 10, which is 
constructed of evaporative material and intended to be replaced as needed. 
Impeller pad 10 is stretched over impeller frame 12 as a sleeve and is 
held in place by the elasticity of the evaporative material. Air is pulled 
into the apparatus by the rotation of the impeller assembly and forced 
outward due to centrifugal force, as in a radial fan, creating a partial 
vacuum at air inlet port 11. Air is directed to air outlet port 13 by 
shroud 17 then through air outlet pad 52 and air nozzle 54. 
Cooling is provided by the evaporation of water that has been injected into 
the air inlet port 11 by water nozzle 43 thus saturating impeller pad 10. 
Water is delivered to impeller pad 10 by electric water pump 34 drawing 
water from a sump at the bottom of line 24 through filter 36, inlet water 
line 38 forcing water through output water line 40 to spray nozzle 43. 
Water, in the form of a fine mist, is directed into air inlet port 11 and 
onto impeller pad 10 by spray nozzle 43. Excess water that has not been 
evaporated will return to the sump by deflection of air/water separator. 
Water not evaporated, in the form of airborne droplets, is caught by and 
saturates air outlet pad 52 which is also constructed of evaporative 
material thereby producing evaporative cooling. Filtration is provided by 
air passing through the wetted material of impeller pad 10 and air outlet 
pad 52, both of which pads are disposable. Water pump 34 is controlled by 
electric switch 48 and impeller motor by electric switch 46 nested in 
cavity 28. Power is provided by main power lead 26 which is connected to 
the power source by cigar lighter power connector 56. Water is contained 
in lower portion of liner 24 and is prevented from rebounding into shroud 
17 by lower lip of air/water separator 14 when wave action occurs due to 
abrupt movement of cooler apparatus 58.