US2293360A - Air conditioning method and apparatus - Google Patents

Description

1942- F. J. REILLY arm.

AIR CONDITIONING METHOD AND APPARATUS Filed Sept. 3, 1935 6 Sheets-Sheet 1 Aug. 18, 1942; F. J. REILLY Emu. ,36

AIR CONDITIONING METHOD AND APPARATUs Filed Sept. 5, 1935 6 Sheets-Sheet 2 M3 7 I03 64 J? i 97 w i |m Wk 'll n P 4 9 2 3 u :1 A a: i

. I W9 W Nam 6W Had I 8, 1942. F. J. REILLY ET m. 93,360

' ,AIR counmioume METHOD AND APPARATUS Filed Sept. 3, 1935 6 Sheets-Sheet 3 Aug. 18, 1942. F. J. REILLY ETAL.

I AIR CONDITIONING METHOD AND AP FABATUS Q She'eis-Sheet 4 Filed Sept. 3, 1955 F. J. REILLY ETAL AIR CONDi'I'IONING METHOD AND APP RATUS Aug. 18, 1942.

6 Sheets-Sheet 5 Filed Sept. 3, 1935 QEERRB k 'A g- 1942- F. J. RE ILLY arm.

AIR CONDITIONING METHOD AND APPARATUS Filed Sept. 3, 1935 GSheets-Sheet 6 I l IHEEHH HEH FJF Patented Aug. 18, 1942 AIR CONDITIONING METHOD APPARATUS AND Frank J. Reilly and Maurice H. Connell, Miami,

Fla., assignors, by mesne assignments, to General American Precooling Corporation, a corporation of Delaware Application September a, 1935, SerialNo. 39,044

6 Claims. (01. 98-6) This invention relates to air conditioning, and more particularlyhas reference to the precooling and preconditioning of cars transporting perishable food products. invention with respect to the precooling andpreconditioning of cars, itwill be appreciated that the inventive concept is of far greater application.

As is well known, it has heretofore been the custom tofill with ice the bunkers of freight cars transporting perishable food products, and to. top ice the products incertain instances. Such practice presents many disadvantages, including the relatively high cost thereof and the consumption of a large amount of time during the course of transit in view of the necessity of stopping along the route for re-icing.

The principal objection, however, resides in the fact that when fruits and vegetables are so' shipped, it is not possible to pick the products in a fullyripened condition, but rather they must be picked.when relatively green. This is due to the fact that with the practice above mentioned, there is a considerable period after the products are placed in the car before they are reduced to the proper temperature. This, of course, impairs the quality of the product, and as aresult, the shipper does not receive a price equal to that which would' be received if the products were picked when fully ripe.

While we shall describe our I While it, has been suggested that loaded freight tained products.

Another. object of this invention is to provide a process for insuring the uniform distribution and passage of cooled and conditioned air throughout the entire contents of a freight car.

Yet another object of this invention isto pro-. vide means for insuring the proper air pressure in various points of a car to obtain the optimum operating conditions.

A further object of this invention is to provide a process and apparatus for the cooling and conditioning of the contents of a car by means of a portable refrigerating device, so that the same may be effectively cooled regardless of the loca-,

tion of the car.

To accomplish the. above, and other important objects, this invention in general embraces the idea of 'quickly and thoroughly cooling the contents of a chamber by means of a refrigerating unit. More specifically, we provide a process and apparatus for the precooling' of a loaded ireight car by means of a portable refrigerating unit that is self-contained and requires little, material.

under such pressures, and in such a manner that there is a uniform distribution of the chilled. air

throughout the lading.

In the accompanying drawings we have depicted one specific embodiment which our inventio'nmay assume, but it will of course be appreciated that variousmodifications may be made therein without exceeding the-scope of our inventive concept.

In these drawings, in which corresponding numerals refer to the same parts:

Figure 1 is a top plan view of a freight car and a portable air conditioning apparatus in an operative position with respect thereto.

Figure 2 is a horizontal sectional view of a freight car equipped with a device for insuring an equal distribution of the chilled air.

Figure 3 is a view along the line 3--3 of Figure 2, looking in the direction of the arrows.

Figure 4 is a view partlyin section and partly inelevation, taken along line 44 of Figure2,

' looking in the direction of the arrows.

Figure 5 is a detail view of the false door employed and the return air duct.

Figure 6 is a side elevation of the refrigerating I unit. M

Figure 7 is a plan view, looking down, of the unitshown in Figure 6.

Figure 8,-is a view along Figure 7.

Figure 9 is a diagrammatic view of they refrigerating cycle.

the line ra t of Figurelll is a sectional view. in detail of the casing for the diffusor.

Figure 11 is a view Oran adjustable false door,

which may be used with our invention,

Figure '12 is a detailed View along the line,

l2--I2 of Figure 11.

Figure 13 is a detailed I 3-43 of Figure 11. v

Figure 14 is a detailed view of the junction of the door section.

view along the line In Figures 1 through 3 there is shown a conventional freight car I of the so-called refrigerator type. This car is provided with the usual doors 2 and 3 located on each side and at the center of the car. As best shown in Figure 2, these doors may be swung outwardly to lie flush against the exterior of the sides.

There is disclosed in Figure 1 a truck, designated generally 5, on the rear of which is mounted a refrigerating unit designated by the numeral 5. This refrigerating unit is made up of a diffuser element 1 and a condenser 8, and necessary compressors and pumps mounted on the truck beneath a protective awning 9.

Referring particularly to Figure 6, the refrigcrating unit is operated by means of a 'power shaft II' driven from the conventional motor of the truck. A suitable power take-oi! unit I2 is provided to operatively connect the shaft II with a drive shaft I3. The drive shaft I3 is mounted on bearings I4 and is provided with a suitable flexible coupling I5. The necessary pulleys, sprockets, or gears, are mounted on the shaft I3 to operate the driven elements of the refrigerating unit.

For instance, a pulley is provided for a belt I6 to drive a compressor I1. Another pulley is provided for a belt I8 which drives a second compressor I9. The compressors I1 and I9 are of a suitable style and capacity to secure the necessary refrigeration, and, as best shown in Figures '1 and 9, these compressors are arranged in parallel for the refrigerating cycle. A water pump 2I is driven by shaft I3 through a suitable pulley arrangement and belt 22.

As best shown in Figure 8, a pulley 24, driven by belt 23, drives a pulley 25 mounted on a common drive shaft for three fans 25. Each of the fans 26 exhausts air from discharge outlets 21 at the top of the condenser unit 8. bviously, the number of fans and outlets in the condenser may be varied as desired.

The pulley 25 also carries a belt 28 which passes over a pulley 29. The pulley 29 likewise is mounted on a common drive shaft for three pressure fans 3| mounted in the top of the diffuser unit 1. Each of the fans 3I' forces air through respective outlets 32 in the diffuser. Here again the number of fans and outlets may of course be varied. I

The condenser element is of the evaporative condenser type. As best shown in Figures 8 and 9. it is provided with an air inlet 33 which passes into the base of the casing. The air is sucked upwardly through the casing by means of the fans 25, and at the same time, water is sprayed downwardly from nozzles 34. The spray falls upon primary condensing coil 35 and a pair of secondary condensing coils 36 and 31. A sub-cooling coil 33 is also subjected to the spray. The air is drawn into the condenser at such a rate as to effect the necessary vaporization of the water that is sprayed onto the condenser coils, and such vaporization extracts sufflcient heat from the refrigerant in the condenser coils to result in condensation of the refrigerant. The condensed refrigerant in the sub-cooling coil is likewise further reduced in temperature.

The unvaporized water collects in the base of the condenser casing and is returned to the nozzles 34 by means of pump 2I and line 39. Make-up water is fed to the condenser from a water storage tank 4| through line 42. It will be appreciated that a relatively small amount of liquid'is lost through vaporization,

. such air.

and the water storage tank best shown in Figure 8 holds suflicient water for operation of the device over a considerable period of time. Such an arrangement, therefore, makes the refrigerating unit substantially independent of the source of water supply.

An eliminator 43 may be placed in the upper part or the condenser to prevent the escape of water that may be entra in the air exhausted from the condenser.

The diffuser element 1 is likewise made up of a casing which is preferably insulated as shown in Figure 10. It will be noted that a shell 44, surrounded by cork insulation 45, is provided. A suitable weather-proofing fabric 45, such as, for instance, canvas, may cover the cork.

Arranged one above the other within the diffuser are cooling coils 41 and 46. The relatively warm air is admitted to the base of the diffuser, passes upwardly over the coils 46 and 41, successively, and then is discharged through outlets 32 under pressure, and returned to the car. As the warm air passes upwardly over the coils and 41 its temperature is lowered, and there is a consequent condensing out of the moisture in Ordinarily this moisture will be laden with the dirt and bacteria picked up by the air in the course of its passage through the contents of the car, and this condensation of the moisture consequently effects a cleansing of the air. It will be noted that the condensate drops to and collects in the base of the diffuser member 1, where it is removed from the cycle and where it is out of contact with the air flow.

The refrigerating cycle is best shown in Figure 9. The refrigerant in a. hot and gaseous condition, after absorbing the heat of the treated air, is delivered by line 45 and branch lines ii and 52 to the compressors I1 and I9, respectively. As heretofore pointed out, these compressors are arranged in parallel, and the compressed gas is delivered from the compressors through lines 53 and 54 to a pipe 55.

Pipe 55 is connected to condenser coil 35, from which coil the condensed and gaseous refrigerant is passed through line 55. So much of the refrigerant as has been condensed in condenser coil 35 passes from pipe 55 into line 51. The uncondensed refrigerant, however, passes through line 55 to condenser coil 35. Th refrigerant passes from condenser coil 35 into line 5!, from which the refrigerant which has been condensed in coil 36 flows into line 5|.

The refrigerant that is still in gaseous form after passage through coil 35, is carried by line 62 to final condenser coil 31. From coil 31 the refrigerant, practically all of which is now in liquid form, passes by line 53 into the liquid receiver 64 located in the base of the condenser unit. Pipes 51 and 5| also discharge their liquid refrigerant into receiver 54.

A safety or blow-off plug 65 is provided for the liquid receiver 54 and is connected by a line 66 to the main or branch hot gas lines leading to the compressors. Therefore, if the pressure within liquid receiver 64 becomes excessive, it is relieved by means of the safety plug.

The liquid refrigerant is withdrawn from receiver 54 and is then passed through sub-cooling coil 38. This further reduces the temperature of the refrigerant and thereby increases the efflciency of the device. From the sub-cooling coil the liquid refrigerant passes by way of line 61 to a liquid dryer 58, and thence by way of line 53 to the expansion valves II and I2 for the cooling coils 41 and 48, respectively. After passage through the expansion valves, the refrigerant enters the headers I8 and I4.

The hot gases from the coils 41 and 40 pass' to hot gas line 49 by way of pipes I5 and I6, respectively.

The difl'user,,compressor and condenser elements are maintained in balance by virtueof a blank switch 11. This switch is connected to the expansion valves II and I2 by means of a line 18 on which is mounted a suitable suction gauge I9. A line 8| from the suction side of the compressor isteed into the line I8. A line 82, tapped into the pressure side of compressor I9, is likewise connected to switch 11. Switch 11 also receives electric wires 88 leading to a commutator.

A duct 84 is adapted to'fit over the discharge outlets 32 of the diffuser element and extends to a false door designated generally 85, which is positioned in the doorwayofthe freight car. The manner of securing the duct 84 to the diffuser air inlet 88, of the diffuser element, and this duct likewise may be sewn around the edge of a cut out section 89 in the base of the false door.

It will be noted that both ducts 84 and 81 are of relatively short length, and therefore there is little opportunity for heat exchange between the air within suchduots and the atmospheric air. These ducts maybe of bellows-like construction, and may be reinforced by rectangular bands 9|, such as shown in Figure 5.

It will therefore be seen that the warm air is exhausted from the car at its base and center, cooled in the diffuser unit, and then returned to the car through the upper duct and under pressure. 1 M

The air may be discharged into the car directly from the opening 86 in the door, but in this event it is preferable that there be stretched over the lading in the vicinity of the door a tarpaulin or other suitable means to prevent short-circuiting of the air current to the opening 89. As best shown in Figure 4, the usual height of the lading is indicated by the dotted line'92. However, of

course, this height may be varied as occasion demands. The spreading of the tarpaulin, therefore, requires a circulation of the incoming air toward the opposite ends of the car.

We prefer that the air shall be. deflected to the ends of the car by means of air ducts which are connected to the inner side of opening 86. It will be observed that one duct 93 deflects the air toward one end of the car and the other duct-94 deflects it toward the opposite end. Preferably these ducts are formed as a single unit with a dividing wall 95-terminating in end portions 96 which diverge. A suitable top 91 and base 98 are provided, and-interposed between the top and bottom are deflectingvanes 99,-.IOI and I02. It will be noted that each of these vanes deflects toward its respective end a portionof the incoming air, and results in a discharge from the duct of a current longitudinally of the car which is substantially uniform throughout the width of the car. Furthermore, it will be noted that the propropriate manner.

vision of the ducts 98 and 94 maintains the loss in velocity at a minimum.

The ducts may beformed of any suitable materials, and if desired, may be suspended from the top of the car by means of rods I03. However, canvas ducts may be employed, in which event the velocity of the wind is sufficient to maintain them in extended position during the operation of the device. If made of canvas, the ducts of course may be sewn directly to the door, as in the case of ducts 84 and 81, but if the inner ducts are not formed of fabric, they may be retained in close engagement with the opening 86 in any ap- It will also be appreciated that while we have shown the two ducts in the form of a single unit, separate ducts may be em-' ployed if desired.

The false door 85 may be of any desired construction, but in Figures 11 through 14, there is.

stuffed with suitable insulating material, form the basis of this door. Associated with the quilts I04 and I05 are frames I06 and I01, respectively, which may be formed of angle irons. .The frames I06 and M1 are extensible, both vertically and horizontally, and being identical in construction and operation, only frame I01 will be described.

Frame I 0'Iis made up of angle iron I08 provided at its base with a right angle extension I09. Secured to this extension in a manner to be described is a base member III. member I l2 may be. eitherformed as a continuation of the basemember III or may be integrally secured thereto by suitable means. 7

The horizontal extensibilitv of frames I06 and I0! is secured by the means which join extension I09 to bar III. As shown indetail in Figure 13, the free end H3 of extension I09 is turned upwardly and is drilled with a threaded aperture adapted to receive a bolt II4. A flange H5 is secured to the bar III, and is drilled to receive a shouldered extension II6 oi the bolt. A suitable head III is formed on the ,bolt and adapted to be engaged by an appropriate instrument.

A slot H8 is cut in extension I09 and headed bolts or lugs lI9.ex end through the slot and are anchored in barIII.

It will therefore be observed that the slot 8 and lugs II9serve to join the extension I09 and bar III; and to maintain the two members aligned, while at the same time permitting a relative longitudinal movement thereof. .Rotation of the bolt I I4 of course results in a spreading or. contraction of the bars I08 and H2 to accommodate these bars, to doors of varying.

- tongue .I2I and .a headed bolt I23v extends through the slot and is'screwed into the upper A second side bar I03 or 2', thus serving as a guide between the two sections I06 and I01. Bolt I23 may of course be unscrewed to disassemble sections I06 and I01.

Spaced in the outline of a rectangle, and of a smaller size than the minimum size of the frame formed by I06 and I01, is a series of hooks I24 on the quilts. Substantially opposite each hook I24 isa hole drilled in the frames I06 and I01. A coil spring I25 is connected to each hook I24 and to the corresponding hole, and is of such size and strength as to constantly maintain the quilts I04 and I 05 under tension. The means for securing together the two quilts I04 and I05 will be described hereinafter.

A toggle arrangement such as shown in Figures 11 and 12 serves to adjust the door vertically. A toggle arm I26 is pivoted to the upper bar I and toggle arm I21 is pivoted to the lower bar I00, the two toggle arms being pivotally connected to a rod I20. Likewise, toggle arm I 20 is pivoted to upper bar 2' and toggle arm I3I is pivoted to lower bar II2. These two toggle arms in turn are pivoted to a rod I32.

The rod I32 is provided with a pair of spaced sleeves I33 adapted to receive for longitudinal movement a rod I34. The rod I34 is bent to form a flange I35 which is drilled with a threaded aperture to receive a bolt I36. A flan e I31 is secured to rod I32 and is apertured to receive the shouldered extension I30 of bolt I36. A suitable head I30 is formed upon the bolt. By means of the adjustability of the toggle through bolt I36, the frame formed by members I06 and I01 may be lengthened to suit varying door heights.

As shown in Figure 12, the free end of rod I34 may be offset, and there is pivoted to this offset portion an arm I. At another point along its length, the arm I is pivoted to rod I20. It will therefore be observed that movement of rod I to the right in Figure 11 results in the spreading of the two toggles, which in turn effects an increase in the height of the door.

In operation, the two sections of the door are assembled with their respective quilts. The edges of the quilts I04 and I are tucked between the frames I06 and I01 and the doorway, and the door is roughly adjusted by means of bolts I I4 for the proper width. The arm I H is then manipulated to spread the toggle and increase the frames to tightly fit the doorway.

As best shown in Figure 5, the quilts I04 and I05 are stuffed with suitable insulating material I42, such as seaweed, treated shredded papers, or some other appropriate material. The quilt I04 is provided with a series of spaced hooks I43, and a series of hooks I44 are arranged on quilt I05 in staggered relationship to the hooks I43. A cord I45 is laced over the hooks I 43 and I44 to secure the proper joinder of the two quilts, and to maintain this joinder during expansion of the door to flt the doorway.

Of course, the necessary gauges and regulating controls are provided for the operation of the cooling unit, and there is also provided an automatic humidity control so that the moisture content of the air within the car may be main-.

tained for any desired degree. This control (not shown) may be of the conventional wet bulb type operating on the compressor to regulate the speed thereof so that the degree of cooling efiected by the coils governs the amount of moisture withdrawn from the air passing thereover.

In operation, the truck 5 is drawn up to the side of the car to be conditioned, the car having previously been loaded. Our invention may be used on a car which has not been previously bunker-iced, or which has been bunker-iced, or even under certain rare circumstances, it may be desirable to practice our invention on a car that has been both bunker-iced and top-iced.

The conduits 03 and 04 are placed inside of the car at the time the false door 05 is arranged in the doorway, and the false door is then ad- .Iusted as described above. The conduits 04 and 01 are secured to the discharge opening 32 and the inlet opening 00 of the diffuser.

The power shaft for the refrigerating unit is thrown into gear and the unit commences to operate. As above indicated, fan 3| exhausts the air from the car, draws it over the cooling coils in the diffuser, and then discharges it under pressure into conduit 04. This fan operates at such a speed that a sufficient pressure in the top of the car is built up to insure a uniform permeation of the cold throughout the load. A sufficient turbulence is also effected to prevent any hot air pockets within the car. Regardless of whether the inner conduits 03 and 04 are employed, a maximum pressure and turbulence is attained, causing a rapid and uniform cooling of the lading.

It is of course appreciated that various products require varied treatments. For instance, in the case of potatoes, the primary result sought is a drying of the air to prevent sliming of the product. On the other hand, in the case of tomatoes, it is necessary to cool the product appreciably in order to prevent deterioration. In any event, a desideratum is an adequate circulation of air, but here again the extent necessary for the proper end results which are sought varies with the product.

We have found that it is necessary to inject the air at a greater velocity and in greater volume during the initial stages than is necessary toward the end of the operation. For instance, to secure optimum conditions for certain products, the air may be injected at a velocity of four thousand feet per minute initially, and this velocity may be reduced to two thousand feet per minute toward the end. Likewise. the volume of the air may vary from twelve thousand to fourteen thousand cubic feet initially to 8000-8800 cubic feet per minute toward the end.

In any event, the air is injected at such a rate, and in such a manner, that the air at the ends of the car and above the load is under a relatively high static pressure built up in these vicinities. It will be noted that by the use of the ducts 03 and 04 the air is deflected by a gradual curve from a transverse path to a longitudinal path, and at the same time this volume of air is distributed in a relatively uniform stream across the width of the car. Consequently, when the air impacts the ends, it has a Very appreciable velocity, and this velocity pressure is transformed into the static pressure above referred to.

Even if the ducts 03 and 94 are not employed, direct short-circuiting of the air is prevented by the tarpaulin, which may be used as above indicated. In this event there is still a sufflcient pressure built up throughout the top of the car to insure a thorough permeation of the entire load.

Therefore, while the ducts 93 and 94 are preferable, it will be seen that even when they are not used, the load in the lower ends of the car is subjected to the cold air and thus reduced to the desired temperature. It is this portion of the load which heretofore has been the most diflicult to cool.

It will of course be appreciated that the pressure diflerential between the top of the car and the bottom of the car is due to the exhaust of air through duct 81. However, and notwithstanding the suction through duct 81, the'air,.

of the products, may at all times be regulated.

It is believed that the advantages of our invention are readily apparent. As mentioned above, an economy in both money and time is effected by our invention. Furthermore, there is a wider range of cooling possible, and the exact degree of cooling desired in any particular situation may be controlled to a nicety. In actual practice, we have found that foods treated in accordance with our invention can secure a higher premium on the market than similar goods which are treated by ice or other prior, processes.

The fact that our unit is portable lends particular attraction to it. Especially in the case of fresh and perishable food products, the cars are usually packed on a siding in the country, and in such event our apparatus may be employed immediately after the. loading of the car.

Numerous other advantages residing in our invention will be appreciated by those skilled in the art..

While, for purposes of simplification, we have depicted and described a car that is not provided with ice bunkers, it will be appreciated that perishables are usually shipped in cars provided with such bunkers. In such case, the major portion of the stream of incoming air of course strikes the bunker bulkhead rather than the end walls of the car. It will therefore be appreciated 'that the term end of the car appearing in the claims refers to the end wallor. in the case of a bunkered car, the bunker bulkhead.

.' We claim:

1. A method of air-conditioning a loaded freight car, comprising withdrawing air from the center and base of the car, conditioning the withdrawn air, returning the conditioned air in two streams to the car at the center and transversely thereof and above the load, deflecting one stream so that its path is longitudinal and toward one end of the car, deflecting the other stream so that its path is longitudinal and toward the other end of the car, each path being substantially the width of the car, and giving the conditioned air such a velocity that upon its impact with the car ends a substantial pressure is built up.

2. In an air-conditioning apparatus for freight cars, a door at the center of the car, an aperture in the upper part of said door to permit the entrance of air to the car interior, a duct within the car communicating with said aperture and adapted to deflect air toward one end of the car, and an aperture in the lower part of said door to permit the discharge of air from the car.-

3. In an air-conditioning apparatus for freight cars, a door at the centerof the car, an aperture in the door through which conditionedair is admitted to the car, another aperture in the door through which air is withdrawn from the car, a duct extending transversely of the car, means for maintaining one end of the duct against the first mentioned aperture, and means in the duct to deflect the air admitted to end thereof.

4. In an air-conditioning apparatus for freight cars, an adjustable door at the center of the car,

other end.

While we have shown and described the preferred embodiment of our invention, we wish it to be understood that we do not confine ourselves to the precise details of construction herein set forth, by way of illustration, as it is apparent that many changes and variations may be made 5. In an air-conditioning apparatus for freight cars, a false door comprising an adJustable frame, and a sheet of flexible material mounted upon the frame and adapted to be folded between the frame and the door jamb.

6. A method of conditioning the load of a freight car comprising withdrawing air from the center of the car and below the load level, conditioning the air. introducing the conditioned air transversely to the center of the car above the load level, deflecting the air so that the major portion thereof passes to the ends of the car, introducing such air to the load near the ends of the car, and passing the air through the load to its point of withdrawal from the car.

' FRANK J. REIILY.

MAURICE H. CONNELL.

the car toward one

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