PORTABLE AIR COOLER AND DEHUMIDIFIER
United States Patent 3774410
A portable air cooler and dehumidifier, comprising at least one closed container enclosing a refrigerant having a latent heat of fusion value below that of ice, said container having at least one wall which serves as a heat exchanger, and at least one blower which causes relatively warm and humid ambient air to pass across said heat exchanger wall, thereby lowering the temperature of the ambient air below its dew point and condensing and removing at least some of its moisture content, and causing a flow of the relatively cooled and dehumidified air in a predetermined direction.
US Patent References:
Air cooling attachment for electric fans
Adler - August 1932 - 1874843
Refrigerating apparatus
Spengler - January 1937 - 2067004
Air conditioning device
Mitchell - November 1938 - 2134881
Flexible refrigerating package production
Brown - June 1940 - 2203591
Ice pack
Kearney - June 1945 - 2378087
Air cooling attachment for electric fans
Adler - August 1932 - 1874843
Refrigerating apparatus
Spengler - January 1937 - 2067004
Air conditioning device
Mitchell - November 1938 - 2134881
Flexible refrigerating package production
Brown - June 1940 - 2203591
Ice pack
Kearney - June 1945 - 2378087
Application Number:
05/154973
Publication Date:
11/27/1973
Filing Date:
06/21/1971
View Patent Images:
Export Citation:
Assignee:
Area Conditioner Corp. (New York, NY)
Primary Class:
Other Classes:
62/430, 62/425, 62/406
International Classes:
F24F3/14; F24F5/00; F24F3/12; F25D17/06
Field of Search:
62/406,430,529,530,426,425
Primary Examiner:
Wye, William J.
Claims:
What is claimed is
1. A portable air cooler and dehumidifier, comprising:
2. A portable air cooler and dehumidifier in accordance with claim 1, wherein:
3. A portable air cooler and dehumidifier in accordance with claim 2, wherein:
4. A portable air cooler and dehumidifier in accordance claim 1, wherein:
5. A portable air cooler and dehumidifier in accordance with claim 4, wherein:
6. A portable air cooler and dehumidifier in accordance with claim 1, wherein:
7. A portable air cooler and dehumidifier in accordance with claim 1, wherein:
8. A portable air cooler and dehumidifier, comprising:
9. A portable air cooler and dehumidifier, comprising:
1. A portable air cooler and dehumidifier, comprising:
2. A portable air cooler and dehumidifier in accordance with claim 1, wherein:
3. A portable air cooler and dehumidifier in accordance with claim 2, wherein:
4. A portable air cooler and dehumidifier in accordance claim 1, wherein:
5. A portable air cooler and dehumidifier in accordance with claim 4, wherein:
6. A portable air cooler and dehumidifier in accordance with claim 1, wherein:
7. A portable air cooler and dehumidifier in accordance with claim 1, wherein:
8. A portable air cooler and dehumidifier, comprising:
9. A portable air cooler and dehumidifier, comprising:
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention:
Localized air cooling and dehumidifying means for relatively short duration use in motor vehicles, homes, offices and the like.
2. Description of the Prior Art:
In the course of a preliminary search conducted prior to the filing of this application, the following patents were located:
Name Number Warren 1,644,408 Madden 1,923,547 Malm 1,972,231 Timms 2,207,956 Lepper 2,557,004
These prior art air coolers, however, suffer from certain significant inherent disadvantages including the following:
1. Ice is used as the primary refrigerant. The normal operative temperature of ice cooled units is 32° F. (under standard conditions) and this is too high for effective dehumidification of the ambient air.
2. The ice is, in most cases, exposed to the air. This has the effect of increasing rather than diminishing the humidity of the air, since evaporation (or sublimation) into the air occurs as an inherent part of the process.
3. In some instances, the condensate from the air is recirculated into the air.
4. The cooling unit is, in most instances, too large or bulky to be placed in a home freezer for freezing the refrigerant. In some instances the cooling unit is not portable and therefore cannot be put into the freezer for that purpose.
5. In most instances insufficient insulation, if any, is used to protect the frozen refrigerant. All (or most) of the refrigerant container walls are exposed to the ambient air, resulting in excessive uncontrolled heat transfer and reduced efficiency of the cooling unit.
SUMMARY OF THE INVENTION
This invention provides a portable air cooler and dehumidifier which suffers from none of the aforementioned disadvantages of the prior art and, instead, provides substantial advantages of its own.
One basic feature of the present invention resides in its use of a refrigerant whose latent heat of fusion value is far below that of water ice. The preferred refrigerant is a water solution of propylene glycol with a latent heat of fusion point in the range of 15° to 18° Fahrenheit, depending upon the particular proportions used. This should be contrasted with the latent heat of fusion point of water ice which is 32° Fahrenheit. The significance of this feature in terms of dehumidification of the air may be seen in the fact that at 100° Fahrenheit, air holds 300 grains of moisture, at 70° it holds 110 grains, at 32° it holds 25 grains, and at 15° it holds 12 grains.
The present device has an initial temperature range between the temperature to which it is reduced in a freezer, e.g., zero degrees Fahrenheit, and its operative (heat of fusion) temperature, e.g., 15° Fahrenheit. The time it takes to reach its operative temperature is a variable, depending upon its B.T.U. capacity, the ambient air temperatures, the volume of air which is caused to flow across it, the extent of heat exchange surface which is exposed to the air, the extent of which the device is otherwise insulated, and other conditions. In preferred forms of the invention, in ambient air having a temperature of 80° Fahrenheit, it takes 15 to 30 minutes for the temperature of the present device to rise from zero to 15° Fahrenheit. During this initial period of its operation it provides a strong but progressively diminishing cooling and dehumidifying action upon the air which is caused to flow across it.
The operative temperature of preferred froms of the device is 15° Fahrenheit, and this temperature is retained, and remains constant, for a period of time ranging from 90 minutes to two hours. During this period of its operation, the device provides strong constant cooling and dehumidifying action, although to a lesser degree than in the initial period above mentioned. This operative temperature of 15° should be contrasted with the 32° operative temperatures of the prior art.
Another important feature of the present invention resides in the fact that the refrigerant is confined within a closed or sealed container. This prevents evaporation of the refrigerant into the air. Heat exchange is effected through a heat exchanger only, that is, through one or more walls of the refrigerant container. The result is that the air which is brought into contact or proximity with the heat exchange wall or walls is effectively caused to lose heat and moisture, in sharp contrast to the prior art devices wherein the air is caused to absorb moisture from the refrigerant. Even where moisture is condensed out of the air in prior art devices, such moisture is in large part reabsorbed and recirculated by the air.
An important feature of the present invention resides in the use of insulation to confine the heat exchange action to the particular surface area which the induced current of air crosses. The result is a highly concentrated cooling action which derives its strength and intensity from substantially the entire B.T.U. capacity of the refrigerant. By contrast, prior art devices leak and diffuse their cooling action through all of the heat exchange walls of their refrigerant container.
Another important feature of the present invention resides in its compact structure and proportions, so that it may be placed bodily in a home-type food freezer chest to freeze the refrigerant to the freezer chest temperature. Some of the prior art devices are not designed for this method of restoring the cooling capacity of the refrigerant. In most cases, the prior art air cooling devices are simply recharged with a new supply of ice in much the same manner as the ice boxes of an earlier age.
Another significant feature of the present invention resides in the angle of deflection of the air stream following its contact with the heat exchange surface area. The air is inducted by the spiral screw action of the fan blades (blower) and it is then drawn into an abrupt 110° turn in a concentrated stream to its forced draft direction. Centrifugal loss of excess moisture results because water is 800 times heavier than air. The excess moisture which is thereby removed from the air collects, in large part, upon the heat exchange surface of the device where it freezes, together with such dust, dirt and pollen which may be entrained therein.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a front view of a portable air cooler and dehumidifier made in accordance with one preferred form of the invention.
FIG. 2 is a back view thereof.
FIG. 3 is a top view.
FIG. 4 is a vertical section on the line 4--4 of FIG. 1.
FIG. 5 is a vertical section on the line 5--5 of FIG. 4.
FIG. 6 is a front view of a portable air cooler and dehumidifier made in accordance with a second form of this invention.
FIG. 7 is a side view thereof.
FIG. 8 is a vertical section with the fan enclosure caps removed.
FIG. 9 is a perspective view showing how the portable air cooler and dehumidifier of FIGS. 6, 7 and 8 is mounted.
FIG. 10 is a side view of a portable air cooler and dehumidifier made in accordance with a third form of this invention.
FIG. 11 is a top view thereof.
FIG. 12 is a vertical section on the line 12--12 of FIG. 11.
FIG. 13 is a horizontal section on the line 13--13 of FIG. 12.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
Referring now to the first embodiment of the invention as illustrated in FIGS. 1-5 of the drawing, it will be seen that portable air cooler and dehumidifier 10 comprises a container 12, refrigerant 14 within said container and a motor-driven rotary fan 16 mounted on said refrigerant container 12. More particularly, refrigerant container 12 is, preferably, of generally rectangular shape although this is not a critical feature of the invention. It has a flat bottom 18 so that it may stand on a flat horizontal surface. It may also be provided with other support means (not shown) for suspending it from an elevated support or mounting it on a vertical support or in any conventional manner and by any conventional means supporting said refrigerant container in any desired location and position.
Refrigerant container 12 is provided with a threaded neck 20 through which the refrigerant may be introduced into the container or drained therefrom, as desired. A threaded cap 22 engages the threaded neck 20 and serves as a closure therefor to seal the refrigerant in the container. A tunnel 24 is formed through refrigerant container 12, the wall 26 of said tunnel constituting an inner wall of the container. The tunnel extends from front to back and, preferably, is open at both ends.
Rotary fan 16 comprises a blade assembly 28 and a motor 30 which drives said blade assembly through a shaft 32 which projects from the motor and on which the blade assembly is mounted. A mounting plate 34 of generally disc shape constitutes the front mounting element by which the motor is supported on the refrigerant container. A bracket 36 serves as the back mounting element for supporting said motor on said refrigerant container. As is clearly shown in FIG. 4, mounting plate 34 is formed with an outer peripheral flange 40, a recessed annular shoulder portion 42 within said annular flange 40 and a central portion 44 which is also recessed but in the opposite direction from the recess of annular shoulder portion 42. As FIG. 4 indicates, motor 30 nests within the center portion 44 and the annular shoulder portion 42 serves as an annular spacer between the motor and wall 26 of the tunnel. Annular peripheral flange 40 bears against the front wall 46 of the refrigerant container.
Mounting bracket 36 has a recessed center portion 50 which corresponds to recessed center portion 44 of mounting plate 34. Mounting bracket 36 is also provided with a pair of end flanges 52 which perform substantially the same function as annular flange 40 of the front mounting plate 34 except that they bear against the back wall 48 of the refrigerant container. Screws 54 interconnect the two mounting plates and wing nuts 56 lock said mounting plates against the front and back walls, respectively, of the refrigerant container. It is by this means that the motor-driven fan is supported on said refrigerant container. Other conventional means may be used to equal effect.
It will now be understood that refrigerant container 12 has at least one heat exchange wall, namely, front wall 46. The axis of rotation of the fan is the longitudinal axis of shaft 32 and it will be observed that said axis of rotation is substantially perpendicular to the plane of the surface of front heat exchange wall 46.
When the above-described device is in operation air is drawn in laterally across the face of the front heat exchange wall 46 as indicated by arrows 60. More precisely the air is drawn toward the axial center of the fan and consequently it flows in radial paths substantially parallel to the front heat exchange wall. The air is then whipped around a 110° turn and directed forwardly away from the front heat exchange wall, as indicated by arrows 62, in the form of a concentrated stream of generally conical formation. As the air is drawn across the front heat exchange wall of the refrigerant container the temperature of the air is lowered and its moisture content is in substantial degree condensed and thereby lost and a relatively cool and dehumidified air stream is blown by the fan toward the user of the device. Since the air stream is concentrated and localized its cooling effect is not diffused.
As has above been indicated, the refrigerant which is used in this device has a latent heat of fusion point considerably below that of water ice. Specifically, the latent heat of fusion point should not be higher than about 20° Fahrenheit. The temperature to which the refrigerant is reduced when placed in a freezer or conventional refrigerating device will depend entirely upon the temperature at which the freezer normally operates. For example, a domestic food freezer chest may operate at a temperature of 0° Fahrenheit. If so, the temperature of refrigerant 14 will be reduced to 0° Fahrenheit if the device is placed in the freezer chest and left there a sufficient period of time. The lower the temperature to which the refrigerant is reduced, the more efficiently does the device function and the longer is the duration of its functioning life.
The refrigerant may be selected from the group consisting of glycerine, ethylene glycol and propylene glycol. The latter is preferred since it is a relatively safe composition, particularly of U.S.P. purity. The preferred proportions are approximately one-third propylene glycol and two-thirds water, resulting in a latent heat of fusion point of approximately 18° Fahrenheit. The proportions may be varied, as known to the art, producing correspondingly different latent heat of fusion points. The refrigerant may also be a water-alcohol solution, preferably a water solution of ethyl alcohol in the proportions of about 20 percent ethyl alcohol and 80 percent water, resulting in a latent heat of fusion point of approximately 20° Fahrenheit. If desired, the refrigerant may be a salt brine wherein the salt is selected from the class consisting of sodium and calcium chloride. When the salt is in the proportion of about 20 percent to 80 percent water the latent heat of fusion point is approximately 20° Fahrenheit.
Referring now to the second form of the invention as illustrated in FIGS. 6-9, it will be observed that there are two fan assemblies 70 and 72 instead of only one as in the first embodiment. These fan assemblies are mounted on a common shaft 74 which is rotatably supported in a bushing 76 which extends through a tubular formation 78 in refrigerant container 80. As is the case with tunnel 26 in the first embodiment of the invention, tubular formation 78 provides an opening through the refrigerant container 80 but precludes escape of the refrigerant. A motor 82 drives the two fan assemblies through a pulley 84 on the motor shaft, a pulley 86 on the fan shaft 74 and a drive belt 88 which interconnects the two pulleys. As will be apparent, the two fans are caused to rotate in the same angular direction. Their orientation is such that both fans function to drive the air in the same direction.
It will be observed that refrigerant container 80 is encased within a housing 90. This housing includes a front wall 92 and a back wall 94 which, in one form of the invention, may simply be snapped or held frictionally in place. The casing should provide insulation to protect the refrigerant and this may be achieved by means of an insulating lining 96 which is applied to the inner surface of the casing, including its front and back wall sections.
It will now be seen that casing 90 provides support for motor 82. The motor is simply attached to the casing by means of a screw 98 or other conventional fastening means. It will also be seen that openings 100 and 102 are provided, respectively, in the front and back walls of the casing. Mounted within these openings are the two fan assemblies 70 and 72. And finally it will be noted that an air space 104 is provided between the refrigerant container and the insulating lining of the casing. Spacers 106 between the refrigerant container and the insulating lining support said container in such spaced position within the casing.
The operation of the device will be understood from the foregoing description of its construction. When the fans are in operation, air will be drawn into the casing through opening 102 by fan 72. The air will then be forced through air space 104 and around the refrigerant container, passing from the back of said container to the front. It will then be drawn out of air space 104 by fan 70 and it will then be projected forwardly away from the front of the refrigerant container in the form of a concentrated air stream. Since the air has thereby been brought into contact with the several walls of the refrigerant container, and since these walls function as heat transfer elements, the temperature of the air will be caused to drop and much of its entrained moisture will be caused to condense out of the air. In consequence the air stream which flows through opening 100 and away from the refrigerant container will consist of relatively cooled and dehumidified air.
It is important to insulate the refrigerant container prior to use in order to minimize the absorption of heat from the ambient air. The casing is itself insulated but openings 100 and 102 should also be covered. This may be done by means of removable covers 110 and 112 which frictionally engage flanges 114 and 116 around said openings 100 and 102. These covers are lined, respectively, with insulating walls 118 and 120. It will be evident that when covers 110 and 112 are positioned above flanges 114 and 116 said covers not only function as closures with respect to openings 100 and 102 but also serve to protect the fan assemblies.
In the use of cooling device shown in FIGS. 6-9, it may be found desirable to suspend said device adjacent the user of the device, e.g., a driver of an automobile. In such case the device would be suspended by means of a flexible cord 122 or similar conventional means from a suitable support such as a plate 124 which is adhesively secured to the windshield of the automobile. Another cord element 126 may attach to the lower end of the cooler to another support below the dashborad of the automobile or the steering column or the like. This may also be done by means of an adhesively secured plate 128 or other conventional means. The position of the cooler may be adjusted by means of screw elements 130 which are provided with bumper elements 132 at their outer ends. These adjusting screws may be set to meet the individual requirements of a particular installation and a particular user. As an illustration, these adjusting screws and more particularly their bumper ends will rest against a dashboard 130 and thereby not only protect the dashboard but also properly position the cooler for efficient functioning and focused cooling effect.
The third form of the invention, as illustrated in FIGS. 10-13 comprises an insulated container 140 containing a plurality of refrigerant containers 142 and 144. Refrigerant containers 144 are conventional and may be purchased on the open market. In one arrangement of these refrigerant containers the larger containers 142 are placed in the bottom of receptacle 140, a metal plate 146 is then placed on said containers 142 and containers 144 are then placed on said plate 146. Containers 144 are arranged in a circle and a cup element 148 is placed within the circle. Motor 150 which drives fan 152 is secured to a plate 154 which corresponds, substantially, to plate 146. Plate 154 is placed upon containers 144 and cup 148 and it will be observed that motor 150 is thereby inserted into said cup.
The entire device is now in operative condition. Receptacle 140 has a cover 156 which would enclose the fan and plate 154 when the unit is not in use but said cover may be swung into open position, as shown in FIGS. 10 and 11, when the device is to be used.
The form of invention shown in FIGS. 10-13 is intended for use when supported on a flat surface such as a floor, chair or table. It may be placed on the seat of an automobile. This is also true of the first form of the invention but the supporting means which is shown in connection with the second form of the invention may also be applied to the first and third forms. In short, any conventional means of supporting or suspending any one of the three devices herein described and shown may be used. Applicant does not claim any specific supporting means.
It should also be understood that the type of motor used is determined by the nature of the power source. For example, if the device is to be used in an automobile having a 12 volt circuit, the motor would be a 12 volt direct current motor. If the device is to be used in the home having the usual 110 volt alternating current, the motor would be a 110 volt alternating current motor. Alternatively, a 12 volt motor powered by a 110 volt circuit through a transformer may be used. All of these possibilities are conventional and known to the art.
1. Field of the Invention:
Localized air cooling and dehumidifying means for relatively short duration use in motor vehicles, homes, offices and the like.
2. Description of the Prior Art:
In the course of a preliminary search conducted prior to the filing of this application, the following patents were located:
Name Number Warren 1,644,408 Madden 1,923,547 Malm 1,972,231 Timms 2,207,956 Lepper 2,557,004
These prior art air coolers, however, suffer from certain significant inherent disadvantages including the following:
1. Ice is used as the primary refrigerant. The normal operative temperature of ice cooled units is 32° F. (under standard conditions) and this is too high for effective dehumidification of the ambient air.
2. The ice is, in most cases, exposed to the air. This has the effect of increasing rather than diminishing the humidity of the air, since evaporation (or sublimation) into the air occurs as an inherent part of the process.
3. In some instances, the condensate from the air is recirculated into the air.
4. The cooling unit is, in most instances, too large or bulky to be placed in a home freezer for freezing the refrigerant. In some instances the cooling unit is not portable and therefore cannot be put into the freezer for that purpose.
5. In most instances insufficient insulation, if any, is used to protect the frozen refrigerant. All (or most) of the refrigerant container walls are exposed to the ambient air, resulting in excessive uncontrolled heat transfer and reduced efficiency of the cooling unit.
SUMMARY OF THE INVENTION
This invention provides a portable air cooler and dehumidifier which suffers from none of the aforementioned disadvantages of the prior art and, instead, provides substantial advantages of its own.
One basic feature of the present invention resides in its use of a refrigerant whose latent heat of fusion value is far below that of water ice. The preferred refrigerant is a water solution of propylene glycol with a latent heat of fusion point in the range of 15° to 18° Fahrenheit, depending upon the particular proportions used. This should be contrasted with the latent heat of fusion point of water ice which is 32° Fahrenheit. The significance of this feature in terms of dehumidification of the air may be seen in the fact that at 100° Fahrenheit, air holds 300 grains of moisture, at 70° it holds 110 grains, at 32° it holds 25 grains, and at 15° it holds 12 grains.
The present device has an initial temperature range between the temperature to which it is reduced in a freezer, e.g., zero degrees Fahrenheit, and its operative (heat of fusion) temperature, e.g., 15° Fahrenheit. The time it takes to reach its operative temperature is a variable, depending upon its B.T.U. capacity, the ambient air temperatures, the volume of air which is caused to flow across it, the extent of heat exchange surface which is exposed to the air, the extent of which the device is otherwise insulated, and other conditions. In preferred forms of the invention, in ambient air having a temperature of 80° Fahrenheit, it takes 15 to 30 minutes for the temperature of the present device to rise from zero to 15° Fahrenheit. During this initial period of its operation it provides a strong but progressively diminishing cooling and dehumidifying action upon the air which is caused to flow across it.
The operative temperature of preferred froms of the device is 15° Fahrenheit, and this temperature is retained, and remains constant, for a period of time ranging from 90 minutes to two hours. During this period of its operation, the device provides strong constant cooling and dehumidifying action, although to a lesser degree than in the initial period above mentioned. This operative temperature of 15° should be contrasted with the 32° operative temperatures of the prior art.
Another important feature of the present invention resides in the fact that the refrigerant is confined within a closed or sealed container. This prevents evaporation of the refrigerant into the air. Heat exchange is effected through a heat exchanger only, that is, through one or more walls of the refrigerant container. The result is that the air which is brought into contact or proximity with the heat exchange wall or walls is effectively caused to lose heat and moisture, in sharp contrast to the prior art devices wherein the air is caused to absorb moisture from the refrigerant. Even where moisture is condensed out of the air in prior art devices, such moisture is in large part reabsorbed and recirculated by the air.
An important feature of the present invention resides in the use of insulation to confine the heat exchange action to the particular surface area which the induced current of air crosses. The result is a highly concentrated cooling action which derives its strength and intensity from substantially the entire B.T.U. capacity of the refrigerant. By contrast, prior art devices leak and diffuse their cooling action through all of the heat exchange walls of their refrigerant container.
Another important feature of the present invention resides in its compact structure and proportions, so that it may be placed bodily in a home-type food freezer chest to freeze the refrigerant to the freezer chest temperature. Some of the prior art devices are not designed for this method of restoring the cooling capacity of the refrigerant. In most cases, the prior art air cooling devices are simply recharged with a new supply of ice in much the same manner as the ice boxes of an earlier age.
Another significant feature of the present invention resides in the angle of deflection of the air stream following its contact with the heat exchange surface area. The air is inducted by the spiral screw action of the fan blades (blower) and it is then drawn into an abrupt 110° turn in a concentrated stream to its forced draft direction. Centrifugal loss of excess moisture results because water is 800 times heavier than air. The excess moisture which is thereby removed from the air collects, in large part, upon the heat exchange surface of the device where it freezes, together with such dust, dirt and pollen which may be entrained therein.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a front view of a portable air cooler and dehumidifier made in accordance with one preferred form of the invention.
FIG. 2 is a back view thereof.
FIG. 3 is a top view.
FIG. 4 is a vertical section on the line 4--4 of FIG. 1.
FIG. 5 is a vertical section on the line 5--5 of FIG. 4.
FIG. 6 is a front view of a portable air cooler and dehumidifier made in accordance with a second form of this invention.
FIG. 7 is a side view thereof.
FIG. 8 is a vertical section with the fan enclosure caps removed.
FIG. 9 is a perspective view showing how the portable air cooler and dehumidifier of FIGS. 6, 7 and 8 is mounted.
FIG. 10 is a side view of a portable air cooler and dehumidifier made in accordance with a third form of this invention.
FIG. 11 is a top view thereof.
FIG. 12 is a vertical section on the line 12--12 of FIG. 11.
FIG. 13 is a horizontal section on the line 13--13 of FIG. 12.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
Referring now to the first embodiment of the invention as illustrated in FIGS. 1-5 of the drawing, it will be seen that portable air cooler and dehumidifier 10 comprises a container 12, refrigerant 14 within said container and a motor-driven rotary fan 16 mounted on said refrigerant container 12. More particularly, refrigerant container 12 is, preferably, of generally rectangular shape although this is not a critical feature of the invention. It has a flat bottom 18 so that it may stand on a flat horizontal surface. It may also be provided with other support means (not shown) for suspending it from an elevated support or mounting it on a vertical support or in any conventional manner and by any conventional means supporting said refrigerant container in any desired location and position.
Refrigerant container 12 is provided with a threaded neck 20 through which the refrigerant may be introduced into the container or drained therefrom, as desired. A threaded cap 22 engages the threaded neck 20 and serves as a closure therefor to seal the refrigerant in the container. A tunnel 24 is formed through refrigerant container 12, the wall 26 of said tunnel constituting an inner wall of the container. The tunnel extends from front to back and, preferably, is open at both ends.
Rotary fan 16 comprises a blade assembly 28 and a motor 30 which drives said blade assembly through a shaft 32 which projects from the motor and on which the blade assembly is mounted. A mounting plate 34 of generally disc shape constitutes the front mounting element by which the motor is supported on the refrigerant container. A bracket 36 serves as the back mounting element for supporting said motor on said refrigerant container. As is clearly shown in FIG. 4, mounting plate 34 is formed with an outer peripheral flange 40, a recessed annular shoulder portion 42 within said annular flange 40 and a central portion 44 which is also recessed but in the opposite direction from the recess of annular shoulder portion 42. As FIG. 4 indicates, motor 30 nests within the center portion 44 and the annular shoulder portion 42 serves as an annular spacer between the motor and wall 26 of the tunnel. Annular peripheral flange 40 bears against the front wall 46 of the refrigerant container.
Mounting bracket 36 has a recessed center portion 50 which corresponds to recessed center portion 44 of mounting plate 34. Mounting bracket 36 is also provided with a pair of end flanges 52 which perform substantially the same function as annular flange 40 of the front mounting plate 34 except that they bear against the back wall 48 of the refrigerant container. Screws 54 interconnect the two mounting plates and wing nuts 56 lock said mounting plates against the front and back walls, respectively, of the refrigerant container. It is by this means that the motor-driven fan is supported on said refrigerant container. Other conventional means may be used to equal effect.
It will now be understood that refrigerant container 12 has at least one heat exchange wall, namely, front wall 46. The axis of rotation of the fan is the longitudinal axis of shaft 32 and it will be observed that said axis of rotation is substantially perpendicular to the plane of the surface of front heat exchange wall 46.
When the above-described device is in operation air is drawn in laterally across the face of the front heat exchange wall 46 as indicated by arrows 60. More precisely the air is drawn toward the axial center of the fan and consequently it flows in radial paths substantially parallel to the front heat exchange wall. The air is then whipped around a 110° turn and directed forwardly away from the front heat exchange wall, as indicated by arrows 62, in the form of a concentrated stream of generally conical formation. As the air is drawn across the front heat exchange wall of the refrigerant container the temperature of the air is lowered and its moisture content is in substantial degree condensed and thereby lost and a relatively cool and dehumidified air stream is blown by the fan toward the user of the device. Since the air stream is concentrated and localized its cooling effect is not diffused.
As has above been indicated, the refrigerant which is used in this device has a latent heat of fusion point considerably below that of water ice. Specifically, the latent heat of fusion point should not be higher than about 20° Fahrenheit. The temperature to which the refrigerant is reduced when placed in a freezer or conventional refrigerating device will depend entirely upon the temperature at which the freezer normally operates. For example, a domestic food freezer chest may operate at a temperature of 0° Fahrenheit. If so, the temperature of refrigerant 14 will be reduced to 0° Fahrenheit if the device is placed in the freezer chest and left there a sufficient period of time. The lower the temperature to which the refrigerant is reduced, the more efficiently does the device function and the longer is the duration of its functioning life.
The refrigerant may be selected from the group consisting of glycerine, ethylene glycol and propylene glycol. The latter is preferred since it is a relatively safe composition, particularly of U.S.P. purity. The preferred proportions are approximately one-third propylene glycol and two-thirds water, resulting in a latent heat of fusion point of approximately 18° Fahrenheit. The proportions may be varied, as known to the art, producing correspondingly different latent heat of fusion points. The refrigerant may also be a water-alcohol solution, preferably a water solution of ethyl alcohol in the proportions of about 20 percent ethyl alcohol and 80 percent water, resulting in a latent heat of fusion point of approximately 20° Fahrenheit. If desired, the refrigerant may be a salt brine wherein the salt is selected from the class consisting of sodium and calcium chloride. When the salt is in the proportion of about 20 percent to 80 percent water the latent heat of fusion point is approximately 20° Fahrenheit.
Referring now to the second form of the invention as illustrated in FIGS. 6-9, it will be observed that there are two fan assemblies 70 and 72 instead of only one as in the first embodiment. These fan assemblies are mounted on a common shaft 74 which is rotatably supported in a bushing 76 which extends through a tubular formation 78 in refrigerant container 80. As is the case with tunnel 26 in the first embodiment of the invention, tubular formation 78 provides an opening through the refrigerant container 80 but precludes escape of the refrigerant. A motor 82 drives the two fan assemblies through a pulley 84 on the motor shaft, a pulley 86 on the fan shaft 74 and a drive belt 88 which interconnects the two pulleys. As will be apparent, the two fans are caused to rotate in the same angular direction. Their orientation is such that both fans function to drive the air in the same direction.
It will be observed that refrigerant container 80 is encased within a housing 90. This housing includes a front wall 92 and a back wall 94 which, in one form of the invention, may simply be snapped or held frictionally in place. The casing should provide insulation to protect the refrigerant and this may be achieved by means of an insulating lining 96 which is applied to the inner surface of the casing, including its front and back wall sections.
It will now be seen that casing 90 provides support for motor 82. The motor is simply attached to the casing by means of a screw 98 or other conventional fastening means. It will also be seen that openings 100 and 102 are provided, respectively, in the front and back walls of the casing. Mounted within these openings are the two fan assemblies 70 and 72. And finally it will be noted that an air space 104 is provided between the refrigerant container and the insulating lining of the casing. Spacers 106 between the refrigerant container and the insulating lining support said container in such spaced position within the casing.
The operation of the device will be understood from the foregoing description of its construction. When the fans are in operation, air will be drawn into the casing through opening 102 by fan 72. The air will then be forced through air space 104 and around the refrigerant container, passing from the back of said container to the front. It will then be drawn out of air space 104 by fan 70 and it will then be projected forwardly away from the front of the refrigerant container in the form of a concentrated air stream. Since the air has thereby been brought into contact with the several walls of the refrigerant container, and since these walls function as heat transfer elements, the temperature of the air will be caused to drop and much of its entrained moisture will be caused to condense out of the air. In consequence the air stream which flows through opening 100 and away from the refrigerant container will consist of relatively cooled and dehumidified air.
It is important to insulate the refrigerant container prior to use in order to minimize the absorption of heat from the ambient air. The casing is itself insulated but openings 100 and 102 should also be covered. This may be done by means of removable covers 110 and 112 which frictionally engage flanges 114 and 116 around said openings 100 and 102. These covers are lined, respectively, with insulating walls 118 and 120. It will be evident that when covers 110 and 112 are positioned above flanges 114 and 116 said covers not only function as closures with respect to openings 100 and 102 but also serve to protect the fan assemblies.
In the use of cooling device shown in FIGS. 6-9, it may be found desirable to suspend said device adjacent the user of the device, e.g., a driver of an automobile. In such case the device would be suspended by means of a flexible cord 122 or similar conventional means from a suitable support such as a plate 124 which is adhesively secured to the windshield of the automobile. Another cord element 126 may attach to the lower end of the cooler to another support below the dashborad of the automobile or the steering column or the like. This may also be done by means of an adhesively secured plate 128 or other conventional means. The position of the cooler may be adjusted by means of screw elements 130 which are provided with bumper elements 132 at their outer ends. These adjusting screws may be set to meet the individual requirements of a particular installation and a particular user. As an illustration, these adjusting screws and more particularly their bumper ends will rest against a dashboard 130 and thereby not only protect the dashboard but also properly position the cooler for efficient functioning and focused cooling effect.
The third form of the invention, as illustrated in FIGS. 10-13 comprises an insulated container 140 containing a plurality of refrigerant containers 142 and 144. Refrigerant containers 144 are conventional and may be purchased on the open market. In one arrangement of these refrigerant containers the larger containers 142 are placed in the bottom of receptacle 140, a metal plate 146 is then placed on said containers 142 and containers 144 are then placed on said plate 146. Containers 144 are arranged in a circle and a cup element 148 is placed within the circle. Motor 150 which drives fan 152 is secured to a plate 154 which corresponds, substantially, to plate 146. Plate 154 is placed upon containers 144 and cup 148 and it will be observed that motor 150 is thereby inserted into said cup.
The entire device is now in operative condition. Receptacle 140 has a cover 156 which would enclose the fan and plate 154 when the unit is not in use but said cover may be swung into open position, as shown in FIGS. 10 and 11, when the device is to be used.
The form of invention shown in FIGS. 10-13 is intended for use when supported on a flat surface such as a floor, chair or table. It may be placed on the seat of an automobile. This is also true of the first form of the invention but the supporting means which is shown in connection with the second form of the invention may also be applied to the first and third forms. In short, any conventional means of supporting or suspending any one of the three devices herein described and shown may be used. Applicant does not claim any specific supporting means.
It should also be understood that the type of motor used is determined by the nature of the power source. For example, if the device is to be used in an automobile having a 12 volt circuit, the motor would be a 12 volt direct current motor. If the device is to be used in the home having the usual 110 volt alternating current, the motor would be a 110 volt alternating current motor. Alternatively, a 12 volt motor powered by a 110 volt circuit through a transformer may be used. All of these possibilities are conventional and known to the art.