US2239190A - Air conditioning method and apparatus - Google Patents

Description

A ril 22, 1941. J. c. CHAMBERS AIR CONDITIONING METHOD AND APPARATU$ Filed Dec. 1, 1953 s Sheets-Sheet 1 April 22, 1941. J. c. CHAMBERS AIR CONDITIONING METHOD AND APPARATUS 4 1, 1935 s Sheets-Sheet 2 Filed Dec.

April 1941- J. c. CHAMBERS 2,239,190

AIR CONDITIONING METHOD AND APPARATUS Filed Dec. 1, 1955 5 Sheets-Sheet 3 April .1941- I J. c. CHAMBERS 2,239,190

AIR CONDITIONING MET-HOD AND APPARATUS Filed Dec. 1, 1933 5 Sheets-Sheet 4 21oEI----T 212 ZOO 29 kzos l I -i* i i 2 4 l l 209 I l April 1941- J. c. CHAMBERS 2,239,190

AIR C ONDITIONING METHOD AND APPARATUS ATTORNz Patented Apr. 22 1941 AIR CONDITIONING METHOD AND APPARATUS Jewel C. Chambers, Dayton, Ohio, assignor, by mesne assignments, to General Motors Corporation, a corporation of Delaware Application December i, 1933, Serial No. 700,452

4 Claims.

This invention relates to a method and apparatus for conditioning air.

It is among the objects of this invention to provide an improvedmethod and apparatus ,for conditioning air in which the dehydrating function of the apparatus is performed by a hygroscopic liquid; and the cooling action is performed, in the major part, by an expanded and enclosed refrigerant.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. l is a view, partly in cross-section and partly diagrammatic, of an apparatus embodying the features of my invention;

' Fig. '2 is a view, somewhat'similar to Fig. 1, showing a modified form of the invention; and

Figs. 3 to 8 inclusive are views somewhat similar to Fig. 1, but also showing other modifications of the invention.

In practicing my invention, a stream of fresh air and a stream of air, recirculated from the enclosure in which the air is to be conditioned, are subjected to the drying action of ahygroscopic liquid and to the action of an expanded and enclosed refrigerant. ,The manner in which the streams of air are treated may be varied somewhat as indicated by the various modifications shown in the various figures.

In the modification shown in Fig. 1, the stream of fresh air It! is subjected to the drying or dehumidifying action of a controlled solution of a lithium halide -like salt, such as lithium chloride, .lithium bromide, lithium iodide, and

, other lithium salts having water vapor pressure reducing characteristics similar to these halides, at the air and liquid contact apparatus 13. The stream of recirculated air Ii, from the enclosure I2, is subjected to the action of a controlled, expanded and enclosed refrigerant by passing it of air thus treated are mixed at 4'5 and are delivered by the electrically driven fan I6 into the enclosure l2. While I have'indicated that the hygroscopic liquid is preferably a solution of a lithium halide-like salt, it is to be understood that many of the advantages of my invention may be obtained by a hygroscopic liquid made of a difierent chemical.

The hygroscopic liquid is controlled to provide desired characteristics to the stream of air passing. in contact therewith. This control may include means for automatically imparting to the solution a predetermined degree of concentration and/or temperature. To this end, the hygroscopic leaving contact apparatus I3 flows through a pipe I! to a concentrating apparatus generally indicated as 20. This includes a tank I8 in which the main body IQ of hygroscopic liquid is mainthrough the bank of coils H. The two streams tained. This tank i8 is connected to the remainder of the concentrating apparatus in such a manner that liquid is withdrawn from the main body I9, is concentrated, and is returned to the main body it. Another portion of liquid from the body I9 is returned to the contact apparatus 13 at the proper concentration and/oritemperature through the pipe 2!.

The concentrating apparatus 20 may be of any desired construction, but preferably, it is of the character disclosed in Fig. 1. In this apparatus, a portion of the liquid from the body i9 is withdrawn by means of the pump 22 and is forced through a heating coil 23 where a predetermined temperature is imparted thereto and from whence it is delivered through the spray-head 24 to be contacted with a stream of air passing upwardly through the contact or evaporating apparatus'25 where the liquid gives off a predetermined amount of water vapor to the air passing upwardly-therethrough and from whence the liquid returns through the pipe 26 to the main body l9.

The coil 23 is heated by any suitable means,

such as a gas burner 21 which is controlled jointly by means of a thermostatic valve 28 controlled from the thermostatic bulb 29 in contact with the discharge from the coil 23. The gas flame is also controlled by means of a solenoid valve 30, which is controlled in accordance with the concentration of the hygroscopic liquid in the body H9 in a manner more fully to be described. The burner 21 is ignited by means of the pilot 3|.

The control for the solenoid valve 30 is indi cated at 32. .This includes a bleeder pipe 33 through which flows a small amount of liquid, representative of the liquid in body i9, taken from the pipe 2| and which is discharged into the chamber 34. In this chamber, there is pro-- 'vided a hydrometric float 35 which is responsive to the concentration of the liquid. This float operates an electric contact arm 36 which energizes and deenergizes the electric control apparatus or relay 31 in such a manner that when the arm 36 rises in response to concentration of the hygroscopic liquid, then the solenoid valve 30 closes and extinguishes or reduces the flame at the burner 21. When the hygroscopic liquid weakens and permits the float 35 to sink, the arm 36 drops and causes the electric apparatus 3i to open the solenoid valve 36 to ignite or increase the flame 21?. The level of the hygroscopic liquid in the receptacle is maintained by means of the overflow pipe 38. Relays of the type indicated at 31 are well known, and therefore are not further described.

When the solenoid valve is opened, the motor 39 is simultaneously started and drives the pump 22 and the blower do to cause the circulation of hygroscopic liquid through the concentrating apparatus, and to force air upwardly from the air intake 4|, through the contact apparatus 25, and out through the air discharge duct 42. This removes water vapor from the liquid flowing through 25 to maintain a substantially constant degree of concentration of the liquid in tank l8.

The hygroscopic liquid from the body I! is delivered to the contact apparatus l3 by means of a pump 43 driven by amotor 44 which is controlled by means of the wet bulb thermostat or hygrostat 45 in the space H which opens and closes the circuit to the motor 44. The liquid being pumped through the pipe 46 is cooled in the cooler 41. The cooling medium flowing through this device may be ordinary city water coming from the pipe 4t and leaving through the pipe 49.

For normal or light loads, the cooling action of city water in' cooler A! may be suflicient, but for abnormal or heavy loads, this cooling action may be supplemented or substituted by the cooling action of a refrigerating apparatus. Thus the bygroscopic liquid leaving the cooler 41 at 4611 may pass through a valve 50 into a coil 5i where it is artificially cooled and returns to the pipe 2! through the valve 52.- The coil 5i may be submerged in water or brine in the tank 53 which is cooled by the evaporator 54 which may be connected with the refrigerant liquefying unit 65 or may be provided with an individual liquefying unit controlled by a thermostat in the tank 53. If desired, refrigerant may be fed to the evaporator 55 through the thermostatic valve 54a con trolled by a thermostatic bulb 541) at the outlet of the evaporator 54.

calibrated so that it has a temperature setting,

above that of the instrument 45. Thuswhen a relatively light load or a normal load occurs on the apparatus, the cooler 41 cools the hygroscopic liquid to a sufficient degree, but when an abnormal or heavy load occurs, then the coolin action oi cooler 41 is supplemented or substituted by that of the tank 53 which imparts a predetermined temperature to the hygroscopic liquid before it reaches the contact apparatus l3,

The stream of recirculated air H is cooled by means of a bank of coils I4. Liquid refrigerant is fed to this bank through the liquid refrigerant pipe Bil, which is provided with branches SI and 62 connected to various expansion valves 63 which feed expanded refrigerant to the various coils of the bank. Thermostatic bulbs 54 are placed atthe outlets of each coil and these bulbs operate their respective expansion valves 63 to maintain I the coils substantially flooded with liquid refriglO mined dry bulb temperature limits.

The valves 63 need not have thermostatic controls 64, but may be set to maintain a predetermined pressure, and therefore temperature within the coils of the bank l4.

1.; If desired, a damper 12 may beprovided, which may be manuallyor automatically controlled, to cause a portion of the stream I I to flow into the contact apparatus l3 or to cause a portion of the stream in to flow into contact with the bank of In the modification shown in Fig. 2, the air in the enclosure 100 is to be conditioned. Fresh air enters'through the duct NH, and recirculated air through the duct M2. The dehydrating contact apparatus Hi3 is substantially the same as the contact apparatus 13 of Fig. 1 and the concentrating apparatus I04 is substantially the same as apparatus 20 of Fig. 1. The bank of coils i5 is modified, however. This bank includes coils I06, I01 and I88 which are connected to individual refrigerant liquefying units 809, Hi] and Ill respectively. Preferably the coils are arranged so that the stream of air flows through them in parallel as indicated diagrammatically in Fig. 2. The dry bulb thermostats H2, H3 and IM control the starting and stopping of the motor compressor units "5, H6 and Ill respectively. The thermostats1l2, H3 and I are calibrated so that their settings or actuating temperatures are slightly different.

One liquefying unit thus starts when the temperature in the enclosure lllii rises to a certain predetermined temperature, the second liquefying unit starts when the temperature rises to a second and slightly higher Predetermined temperature and the third thermostat operates whenthetemperature rises to a third and still higher temperature. The stopping temperatures of the various thermostats are also calibrated, so that one liquefying unit Stops when the temperature drops to a predetermined temperature, the second liquefying unit stops, when the temperature reaches a second and also predetermined temperature, and the third liqueiying unit stops when the temperature reaches'a third and still lower predetermined temperature. Each of the liquefying units may be substantially the same as the unit 65shown in Fig. l. The concentrating unit I04 may be controlled by one or two i wet bulb thermostats or hygrostats' I20 substanm tially in the same manner that the unit 20 is con trolled in Fig. 1, it being understood, that two wet bulb thermostats or hygrostat's may be used for the control of the concentratin unit 34 exactly as unit Ziiis controlled in Fig. l.

c5 The air streams are mixed at E2! and are forced by motor driven fan I22 through duct lit into enclosure Hill.

In Fig. 3 a space I25 is to be conditioned. Fresh air enters through duct Sand recirculated air is drawn through the duct I21. The dehumidifying or contact apparatus I28 acts on the fresh airstream while the bank of'coils i253 acts on the dehydrated fresh air mixed with recirculated air at i351. The bank of coils I29 is provided with a refrigerant liquefying unit l3l which is con- -2,2so,ioo

connected to a plurality of liquefying units substantiaily as indicated in Fig. 2, the refrigerant liquefying unit or units being controlled respec tively as vdescribed in connectionwith those figures. Also, the concentrating apparatus ltd may be of the character and is controlled as described with respect to apparatus 20 in Fig. 1. The treated air is delivered by the motor-driven fan I35 into the enclosure m5.

In Fig. e, the air in space 1% is to be conditioned. Fresh air enters at It! and recirculated air flows through duct air. the recirculated air are mixed in the chamber I53 and pass through the contact apparatus Ifid. Thereafter the mixed air passes through the bank of coils E55. and is returned by means of the motor-driven fan i585 to the enclosure till.

The bank of erant liquefying unit means of the dry bulb coils W5 is connected to a refrigifim which is controlled by thermostat B51 in the space Hill. The concentrating apparatus E58 is controlled by means oi one or more wet bulb thermostats or hygrostats I59. In this instance also, the bank of coils I55 may be operated by a single liquefying unit in the e manner as the bank it in Fig. 1 or by a plurality of liquefying units in the same manner as the bank lot in Fig. 2, it being understood that the proper number of thermostats, if necessary, and liquefying units are to be provided if the bank of coils 85b is to operate in the same manner as the bank :05. The concentrating apparatus 858 may be similar to the apparatus 20 and may be controlled in the same nner as that apparatus is controlled, it being understood that two wet bulb thermostats or hygrostats n be provided for the control in the same manner as described in Fig. 1.

In Fig. 5, the air in enclosure 5 is to be conditioned. Fresh air enters through the duct I16 and recirculated air flows through the duct I'll. The fresh air is dehydrated by the contact apparatus W8 and-the recirculated air is cooled by the bank of coils H9. The bank lid is connected to the liquefying unit 18d which is controlled by the dry bulb thermostat Edi. The concentrating apparatus contact apparatus 8, is controlled by one or more wet bulb thermostats or hygrostats I83.

The fresh air and I82, which supplies the y it is possible to provide Here again, the liquefying unit Hill and the bank of coils H8 may be operated as described with respect to Fig. 1 or may have the plural structure and operation of Fig. The concentrating apparatus 982 may be identical with and may be controlled exactly the same as the apparatus 20 in Fig. 1, having, if desired, a double control from the enclosure as in. Fig. 1.

In Fig. 6, the air in enclosure 2% is to be conditioned. Fresh air flows through the duct 2M. One stream of return air 202 and mixes with the fresh air in the chamber can. This mixture is cooled by means of the bank 204. Anotherstream of recirculated air flows through the duct 205 to the drying or con:

- tact apparatus not. The air thus conditioned is mixed in the chamber Ml and is delivered by the fan 20% into the enclosure we. The contact flows through the duct apparatus 206 is provided with a concentrating apparatus 209 which is controlled by one or more wet bulb thermostats or hygrostats 210, the control and concentrating apparatus being identical with the concentrating apparatus zu and its control as described in Fig. 1. The bank of coils 263 is connected to one or more refrig- 2 controlled by one or manner similar to the Figs. 1 and -2 respecerant liquefying units more thermostats H2 in a corresponding controls in tively.

In Fig. 7, the air in enclosure 225 is to be conditioned. Fresh air enters through the duct 226 and recirculated air enters through the duct 221.

- These streams of air are mixed in the chamber One portion of the mixture is dried by. the and another portion of the mixture is cooled by means of the bank of coils 23d. I'he portions thus conditioned are mixed in the chamber 23! and the mixture is delivered by the fan 232 into the enclosure 225. The drying or contact apparatus 229 is connected to a concentrating apparatus 233 which is controlled by means of one or more wet bulb thermostats or hygrostats 234, the concentrating apparatus and its control being substantially identical to the apparatus 20 and its control in Fig. 1. The bank of coils 230 is connected to one or more refrigerant liquefying units 235 controlled by one or more dry bulb thermostats 236, the bank of coils, the liqueiying units and the controls being substantially identical with the corresponding apparatus in Figs. 1 and .2 respectively.

Ill Fig. 8 the air ditioned. Fresh air 228. contact apparatus 229 in enclosure 250 is to be conflows through the duct HI and recirculated air flows through the duct 252. The recirculated air is dehydrated by the action of the drying or contact apparatus 253. A portion of the dried recirculated air is mixed with the fresh air at 254. Another portion of dried recirculated air passes through the duct 256 and is mixed in the chamber 251 with the air from b 25%, the mixture being delivered by the fan 2% into the enclosure 250. The bank of coils 265 is connected to one or more refrigerant liquefying units 259 which are controlled by one or more dry bulb thermostats 260 substantially in the some er as described in Fig. 1 or 2. A damper it! may be controlled by the wet bulb thermostat or hygrostat'lliz to cause more air to enter the mixing chamber 256 or the duct 256 as desired.

I have shown several embodiments oi my invention. It is to be seen that, by my invention, air in an enclosure, by a stream of air flowing into the enby subjecting all or portions of the air in said stream to a refrigerating action and to a drying action. and, if desired, by varying the intensities of said actions. Thus the intensity of the refrigerating action may be variedin accordance with certain conditions, such as dry bulb temperature conditions, and the intensity or the drying action may be varied in accordance with these or other conditions such as relative humidity conditions. Thus, air may be maintained in an enclosure to create satisfactory comfort or industrial conditions which has a sufliciently constant dry bulb temperature and a sufficiently constant relative humidity, as desired. by autcmati; cally varying the intensities of the refrigerating action and the drying action independently or each other.

While the form of embodiment of maintainin closure and the invention as herein disclosed, constitutes a preferred term, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. The method of conditioning air for an enclosure which comprises contacting a stream oi air with a bank of individual heat exchange units, operating varying numbers of said units in proportion to the temperature change required, contacting another stream of air with a hygroscopic medium, controlling a hygroscopic function of said medium in accordance with relative humidity conditions within said enclosure and discharging said streams in said enclosure.

2. Themethod of conditioning air for an enclosure which comprises contacting a stream of air derived from said enclosure with a dehydrating medium, mixing a portion of said air with fresh air, contacting said mixture'with a cooling medium, controlling said cooling medium in accordance with psychrometric conditions in said enclosure, and combining said cooled mixture with the remaining portion of said dehydrated air.

3. The method of conditioning air for an enclosure which comprises contacting a stream 01' air derived from said enclosure with a dehydratlng medium, mixing a portion of said air with fresh air, contacting said mixture with a cooling medium, controlling said cooling medium in accordance with psychrometric conditions in said enclosure, combining said cooled mixture with the remaining portion 01' said dehydrated air,

and controlling said proportions in accordance with the wet bulb temperature of the air in the enclosure.

4. Heat exchange apparatus for supplying conditioning air to a space to be served comprising means for drying air by contacting air with a hygroscopic medium, a plurality of air cooling coils, a refrigerant compressor for each of said coils for supplying a refrigerant to be evaporated therein, means for passing air to be conditioned simultaneously in contact with all of said coils, means for varying the flow of air over said coils, means responsive to the temperature or the reirigerant returning from each of said coils for controlling the supply of refrigerant thereto, means for discharging the air thus cooled and dried into ,a space to be conditioned and means responsive to the thermal condition of the air in said space for controlling the operation of the compressors.

JEWEL C. CHAMBERS.

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