US2513517A - Air conditioning for crane cabs - Google Patents

Description

July 4, 1950 i B. B. REILLY AIR CONDITIONING FOR CRANE CABS 4 Sheets-Sheet l Filed Aug. 10, 1945 INVENTOR Bertram 15.. Emily yaw m Madam M4 ATTORNEYS y 1950 B. B. REILLY AIR CONDITIONING FOR CRANE CABS 4 Sheets-Sheet 2 Filed Aug. 10, 1945 F "by w v Q? a 3 j r 4 m A. E

Z m J m ftam w 5 2 ATTORNEYS July 4, 1950 a. a REILLY AIR CONDITIONING FOR cm CABS 4 Sheets-Sheet Filed Aug. 10, 1945 INVENTOR BerD"a.mB. Re1LZZ 47 3 M M 1W ATTORNEYS July 4, 1950 B. B. REILLY AIR CONDITIONING FOR CRANE CABS 4 Sheet s-Sheet 4 Filed Aug. 10, 1945 INVENTOR Ber iramllfie ATTORNEYS Patented July 4, 1950 Bertram B. Reilly, Ben Avon, 2a., assignor to Dravo Corporation, Pittsburgh, Pa., a-co'rpora- H tion of Pennsylvania.

' Application August 10, 1945, S eria1No. 609,978

3 clai s. (01. 62 129)" My invention. relates to air-conditioning, particularly to. the air-conditioning of, industrial plantswhere high atmospheric temperaturesprvailj, and the air is laden. withdust and dirt.

The invention has been. developed more particularly, though not exclusively, for conditioning] the air within the control cabs of mill cranes which travel overhead, and carry red hot ingots, or ladles of moltenmetal". steel mills, and lik plants,. the atmosphere is laden with particles of dust and ash, and the temperature prevailing. around. the cranes ma average as high. as one hundred and sixty degrees Fahrenheit.

.The problem of air conditioning regions or rooms exposed to such excessive atmospheric conditions has never been satisfactorily solved heifetof'ore. The problem, incid'entally, is. complicated by the violent vibration, to which the. air-con: ditioning apparatus is subjected. when. the. cranes, are in service, and is further complicated, by the practical desirability, if not necessity, of providing air-cooling, or refrigerating mechanism which has capacity to operate with adequate,

cooling] effect, while avoiding the use. of cooling, water, it being understood that the use of 0001 ing water in overhead cranes presents a distinct. hazard. where molten. metal is being handled. The present invention consists in certain new and. useful improvements in apparatus for and method of conditioning air'under the abnormal or excessive atmospheric. conditions outlined above. The invention will be understood upon reference to the. accompanying drawings, in which: Figure 1 is fragmentary viewin perspective of. a mill crane as used in the process of pouring molten steel from a ladle, into ingot, molds, the operators cab of such crane being" equipped with an air-conditioning unit which, in exemplary way, embodies the invention;

Figure 2 is a viewin; perspective and to iarg er scale of the air-conditioning unit;

Figure 3 is a view to yet larger scale, showing the air-conditioning unit in longitudinar section;

Figure 4% is aview of the unitinflong'i'tu'di'r'ial section, on the" horizontal plane ure 3-;

Figure 5 is a; view of the unit in longitudinal section, on the horizontal pIane- V V of Figure Figure dis a view of the unit incross section, Onthe'vertica'l plane VI -VI of Figure 3 Figure? is aviewo: theunit in cross section, on the vertical: plane VII-VII of Figure Figure 8' is a fra mentary view of the unit inof Figured; andi i 21' Figure 9 is, anelectrical wiring diagram. In Fl gure 1 of. the drawingsthe, reference numerarz. indicatesthe traveling. carriage of an overhead steel mill crane}. and 3 the. operators.

cab. which is, suspended from the crane. carriage.- and. adapted to travel. therewith. A ladle:-4- of nioltenstee1 is sustained on the hoist tongsbr hooks 5;, which inturn aresuspended from the trolley winch, mechan-ismfi. Within the cab an operator isenclosed and screened, by means of observation windows, from the excessive heat and dirt. of the atmosphere surrounding. hot metal ladleand cab. Withinthe cab are the controls, by means of. whiehthe travel ofthe crane carriagev 2, the operation of the winch 6 to raise'or lower the'supponted ladle 4, and the traversal of the winch. and they supported ladle upon the carriage are all controlled. by the operator, as need be,-,during; the castingof molterrsteelinto=- the ingot: molds L and operation are well: known in the art, andfurther referenceisnot required for a full un-' steel;, Lift" lugsv H) are provided on the frame, .whereby the unit, may be picked up"- and hoisted to the pointiwhere:installation is" to be made, on the? roof on the cab: 3 inthis case; Atthe four.

cornerspofc the bottom on the frame. 9 rigid lugs H extend laterally; "toz seat: upon vibration-ah .so'rbing'i mounts: 2' of any off the suitable types now available; on the market, the mountsbeing secured to the cab roof structure'- and the lugs H of the unit 8 seated; and? anchored thereupon. The'JtQp0f* the housingrof the unit is formed: of

two: covers l3" and H? that may' b'e removedf'to give access to the mechanism contained with in, and? the; other walls and: flodrof the housing tions" presentl' yto be described;

The interior of the housing is divided by apartition I 5 into two; chambers" and B.' This partitiom as "well as the external: side walls; the I floor and: the cover of the chamber A" are con- The details of crane structure 3 between steel sheets I1, thereby constituting the chamber a thermally insulated structure.

Within the insulated chamber A is a heatabsorbing device [8, consisting of a conventional type of evaporator, energized by means of a fluid refrigerant that is supplied from refrigerating mechanism organized in chamber-B, as,

will presently be described in greater detail, al'-' though at this point it is to be especially noted that the refrigerant is one that, under pressures in the order of from 120 to 150 pounds per square of 190 F., may be condensed from gaseous to,

The refrigerant known to, the art liquid state. as Freon No. 114 (dichlorotetrafluoroethane) has been found to comprise a refrigerant having these essential characteristics;

inch, and at a relatively high temperature, say

an air-filtering inlet 28 is provided in the side wall of the chamber A on the left of the parti- "tion 19; of. Figures 7 and 2. A deflector vane 29 extends, inclined, partway across the path of The heat-absorbing device or evaporator I8 is arranged adjacent to the top of a vertical sheet metal partition l9, as shown in Figures Sand 7. In the floor of the insulated chamber A an outlet 20 opens on the right-hand side of the partition l9 (Figure 7), and an .inlet 2 l 'ope n s ,on

the left-hand side. The roof of the crane cab 3 is provided with openings (not shown) .corre sponding to the openings 29 and'2 l,, and ,tubes T22 and 23 are used to establish. substantially airtight communication between the outlet and'i'nlet openings 20 and 2| of the-refrigerating unit 8 and the saidopenings in the roof of thecrane" cab.

In the chamber A, a mu, drivenby an elecif tric motor 25, is arranged'to impel air outward throught the outlet 20 into the room or" space within the crane-cab,"and at the delivery endof tube 22 a deflector 22a is positiohedgtofdiifuse and spread the stream of air thus impelledinto the cab. I

Adjacent to the evaporator "or heat-absorbing device H? the partition l9 is windowed, and such window is screened by-an airfilter 26. When the fan is set in operation and a stream of air is delivered into the cab-fromphamberA"on'the right-hand side of the partition l9,fair is simul taneously drawn through the air filter 26 from the space on the left-hand side of the partition, and such stream of air passes over the heat-absorbing surfaces of theevaporator l8. Under the suction thus produced in the space'on the left of the partition l9, air is drawn from the cab 3 through the inlet 2|. Accordingly, it'will be understood that a stream of air is circulated from the chamber A to the interior of the cab 3 and back again. In the cyclic fiow of suchstream the air is cleansed bythe' filter 26 and 7 H pressor.

air flow through the passage to the left of the partition [9 (Figure .7), and it is under the aerodynamic effects established by such vane that the make up air is drawn from the outer atmosphere into the circulating stream. The make-up air thus drawn into the circulating stream is cleansed by both the filter 28 and the filter 26, and is cooled by the heat-absorbing device l8 before entering the cab 3. This make:

up air not only replacesthecool airby -passed from the circulating stream for, the purposes alluded to, but also furnishes the essential,

fresh air to theinterior of the occupiedcab. The refrigerating mechanism in"'chamber ,B

which energizes or supplies the refrigerant to, 5 the heat-absorbing device l8 comprises a reciproeating compressor 30, shown in side, elevation in Figure 3 and indicated,diagrammatically in Figure 4. The compressor is,driven by an electric 3 motor 3| belt connected, as at 32, .to the com- The compressor, receiving refrigerant in gaseous condition from the evaporator l8, compresses the refrigerant and delivers it, by way of a pipe 33 (fragmentarily shown in Figure 5) to the coils 34 of a condenser 35; from the con- ;.,denser 35 the refrigerant, condensed to liquid,

form, but approximately at its boiling point, is fed through a pipe 36 into a receiver .31; from receiver 31 the relatively hot liquid refrigerant,

is fed through a pipe ,38 and a strainer 39 and dehydrator 40 into a tubular coil of metal tubing cooled. by the heat-absorbing device I8, and thus the desired atmosphericconditions' are estab- 1 lished and maintained in the crane operators cab 3, it beingnoted that'the'insulated walls of chamberA substantially inhibit the influx of heat from the outer ambient atmosphere-to the circulatingiair stream;

Due to the high temperature of the air surlet of the compressor through a pipe. 48. In its rounding the cab 3 and the unit'8, the problem' of dissipating the heat which is absorbed. from the air stream circulating-rthrough'chamber A- and the interior of the cab is.' acute, and the high emcacy of the apparatus and method of this inful effect ,of excessive temperature. .More-par ticularly, an outlet 21 opens laterally from the space to the left. (Figure 7)- of the partition/l3 4 la within a heat-exchanger 4 l .wherein the liquid refrigerant is cooled below its boiling point;

from, the heat-exchanger ,M' the.- cooled liquid refrigerant is led through a line 42 (Figure 4) to a thermostatic expansion valve 43, whence the liquid refrigerant under reduced pressure enters the usual inlet manifold 44 from which four feeders 45 open into the passages in the evaporator, in which the liquid refrigerant boils and/or -evaporates, with the consequent absorption of heat from the air circulated over the external surfaces of the evaporator tubes. 7 The cool. gaseons refrigerant leaves the evaporator by way of an exhaust manifold 46, and,;fiowing through a pipe 41, enters the space in the heat-exchanger 4| that surroundsthe coil Ma through which a the liquid refrigerant flows on its Way to the expansion valve 43. leaves the heat-exchanger and flows to the inflow downward around the tubular coil Ma withr in the heat-exchanger, the cool gaseous refrig'ferant=;absorbs heat from the liquid refrigerant advancing through the coil to'the expansion valve 143, and thusthe liquid refrigerant is subcooled below its saturation temperature, whilethe gaseous refrigerant returning from the evaporator is correspondingly heated. The heat imparted to the gaseous refrigerant superheats The gaseous refrigerant 51 operating in excessive atmospheric temperatures, since by such superheatingit becomes possible to compress the gaseous refrigerant to the high pressures, required for high temperature operation, without the gas'con'd'ensingin the compressor, the compressor being essentially otlthe positive displacement type in'wliichl the presence of liquid would obviously proveyvery damaging:

The heat'is removedfrom the conderiseizby means of an air..=blast..generatedrby a blower 4,5; connected by a. belt-and-pmilley" drive l1to= the. same motor 3|. that drives the-compressor; and the. intake air for this blow'er is drawn'from the atmosphere in. chamber B, the atmosphere in such chamber comprising air drawn from the" outer atmosphere through air filters 5i mounted in one or more of the side walls of the said chamber B. This high temperature air from the outer atmosphere is effective to condense the refrigerant by virtue of the high compression pressures made feasible by the apparatus described, plus the character of the high-boiling point refrigerant employed, and plus the high velocity and quantity of air driven over the finned surfaces of the condenser tubes. The blast of air emerging from the nest of condenser tubes is discharged into the outer atmosphere through an opening 52 in the wall of the housing of the unit. The type of pressure blower used permits the use of a multiplicity of condenser units, as indicated at 35.

Since the air drawn by the blower into the chamber B is cleansed by the filters 5|, it becomes practical to employ conventional motor starters and controls for the apparatus; that is to say, relatively expensive protected controls would have to be used but for the fact that all of the air within the housing of the unit is clean. While the air drawn into chamber B circulates within the chamber and affords a certain degree of beneficial cooling effect upon the various pieces of apparatus therein, the cooling effect thus gained from the air at 160 F., more or less, is not adequate for the motor 3|. It is the motor 3| in this case which is treated with the cool air by-passed through openings 21 from the stream circulating within and between the chamber A and the interior of the crane cab. The by-passed air is drawn through a duct 53 by means of a fan 54 whose impeller is mounted upon an extension of the shaft of blower 49, and from the fan 54 the cool air is delivered through a duct 55 (Fig. 6) to the casing of motor 3|, and serves to keep the motor windings from overheating. This air, upon flowing through the motor easing, emerges in chamber B, where it is mingled with the air delivered by blower 49 to the condenser, wherefore any capacity for cooling that remains in the air emerging from the motor casing is not lost but is placed at the disposal of the condenser 35.

The casing of the motor starter is indicated at 56 in Figure 3 of the drawings, and the wiring of the various controls is represented in the wiring diagram in Figure 9. The controls within the broken-line rectangle 51 are arranged within the cab 3, while those within the rectangle 58 are located within the air-conditioning unit 8. The motor starter 56 is a known piece of electrical control apparatus that is connected in conventional manner to the windings of the motor 3!, as indicated diagrammatically in Figure 9, and a detailed description of such conventional practice is not required for an underlotthan in the fol- ,box it and lines-52 tothe? motor starter 55,

which operates tocontrol the. motors 3,! and 25 in a manner conventional in; Dre-existing airconditioning: units, although it may be, mentioned: that a pressure'stat t3'responsive to the pressure of the gaseous' refrigerant leaving the evaporator L8 is. arranged to. open and close circuit line 64 that extends between the motor starter 56 andthe switch 65 in the cab, that controls the. air-circulating fan motor 25 which is'v energized through circuit 8.5. The circuit 64, includes a manual open -and-close switch 61;,

Various modifications and changes may be made in the exemplary structure illustrated and described, without departing from the spirit of the invention defined in the appended claims.

I claim:

1. An industrial air-conditioning unit for a room exposed to abnormally high atmospheric temperatures, said unit including two chambers, at least one of which is provided with heatinsulated walls, heat-absorbing device in said insulated chamber, an inlet and an outlet opening through the walls of the insulated chamber, means for circulating air in a stream exiting through said outlet to said room and returning I from said room through said inlet into said insulated chamber, refrigerating mechanism arranged in the other of said chambers, the latter chamber having extensive walls formed of airfiltering panels and including an air outlet, said refrigerating mechanism including a compressor, a condenser, a blower having an inlet in said latter chamber, an electric motor connected to drive said compressor and blower, and motor controls, and said blower being arranged to draw filtered air from said latter chamber and to direct such air upon said condenser and through the outlet in the wall of the chamber.

2. Industrial air-conditioning apparatus for operation in an ambient atmosphere having an unnaturally high temperature, said unit comprising a heat-insulated chamber having an inlet and an outlet opening through its walls, means for circulating air in a stream entering through said inlet and exiting through said outlet, a heat-absorbing device arranged in said chamber in the line of air circulation, a refrigerant, and refrigerating mechanism arranged externally of said chamber for supplying said refrigerant to said device, said mechanism comprising a compressor for said refrigerant, a condenser connected to receive compressed refrigerant from the compressor, an electric motor for driving said compressor, a duct connected to said motor for by-passing air from said circulating stream to the windings of said motor, and an air filter through which air is admitted to said circulating stream from the outer atmosphere to replace the motor-cooling air by-passed from the stream.

3. Industrial air-conditioning apparatus for operation in an ambient atmosphere having an unnaturally high temperature, said apparatus comprising a heat-insulated chamber having an inlet and an outlet opening through its walls, means for circulating air in a stream that enters through said inlet and exits through said outlet, an evaporator in said chamber in the line of air flow between said inlet and outlet, a refrigerant, refrigerating mechanism arranged externally of said chamber comprising a, compressor connected to receive refrigerant in gaseous condition from said evaporator, an electric motor for driving said compressor, a duct leading from a point communicating with said circulating air stream to the housing of said motor, means for impelling air through said duct into said motor housing, a

condenser connected to receive compressed re- ,frigerant from said compressor, connections including an expansion valve for delivering the condensed refrigerant to said evaporator, and

means arranged externally of said insulated chamber for abstracting heat from the condensed refrigerant flowing from said condenser to said evaporator while superheating the gaseous refrigerant flowing from said evaporator to said compressor.

BERTRAM B. REILLY.

v REFERENCES CITED The following references are of record in the file oi this patent: I V

UNITED STATES PATENTS

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