USRE18831E - Method of cooling and drying air - Google Patents

Description

W. L. FLEISHER METHOD oF COOLING AND DRY-:Nq A IR May 16,1933.

Original FiledNoy. 30, 1927 JNI/IENTOR.

A TTORNEYS.

.Reissued May 16, 1933 l jtJNI* 1-ED STATES .PATENT OFFICE WALTER L. FLEIBHEB, OF NEW CITY, NEW YORK, ASSIGNOR THE COOLING & AIR

" CONDITIONING CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF -NEW YORK METHOD OF COOLING .AND DItYING AIB.

Orig-ina] No. 1,819,643, dated August 18, 1931, Serial No. 236,650, filed November 30, 1927. Application for .reissue led September 29,

tems, where dehumidification is required, it

is necessary to bring `the air into contact with thewash water at or below the dew point tohe maintained, in order to effect the moisture i l, extraction. This requires the bringing of the air from the dry bulb telnperature to the dew point, as well as the extraction ofthe moisture and its heat content. This first is a waste of energy since the temperature must be subsequently raised in order to render-the air suitable for Ventilating purposes. This requires aconsiderable quantity of refrigeration, which does not represent useful Work. With such a. system, moreover, the refrigera- -tion itself becomes expensive by reason of the fact that the heat units are extracted from the moisture at comparatively low'temperature.

It is an object of this invention t0 produce a system in which satisfactory Ventilating conditions may be readily maintained with an economy of refrigeration.

In certain classes of Ventilation the problem is primarily one of dehnmidification and cooling. This is particularly true of theatre Ventilation where, during operation, even in the winter months, the heat and moisture given ofi' lby the occupantsis, in itself, too great for comfort.

In a system in which dehumidieation is effected by spraying the air with water, the^ air leaving the spray chamber is at a certain dew point having a quantity of moisture suitable to correct the lroom conditions. Where a suficient quantity of water is 'available from an external sonrce, of ateinperature at or below the dew point to vbe maintained within the Washer, the cooling and dehydrating may be effected without mechanical refrigeration. In general, however, it is desii'able to condition'intensively a portion of thc Vair and subsequently dilute that conditioned air with unconditioned air. Vhere such a system is employed, it necessitates that 1932. Serial No. 635,362.

the spray chamber be maintained at a still lower temperature than --where the air is all conditioned, and this-requires a still lower temperature of the water supply.

In accordance with this invention, it has been found that a silica compound, desig.

nated as silica gel, possesses the property of absorbing moisture' from the air hygroscopically even though the latter be far from Saturated, and without refrigeration. This makes it possible to extract the surplus moisture from the air without the .necessity "of lowering its temperature far below..the ultimate temperature desired, so that the direct cooling effect upon the' air may be confined to bringing the air to the desired sensible telnperat-ure after the properquantity of mois-A ture. has been extracted.

The'invention accordingly comprises the several steps -and the relation and order of one or more of such steps with respect t0 each of the others, and the apparatus embodying features of construction, combinations -of elements and arrangement of parts which are adapted to effect such steps, all s exemplified in the following detailed disclosure, and the scope of the application of which will be in-- dicated in the claims.

1 is a diagrammatic plan of a Ventilating system embodying this invention.

Fig. 2 is a diagram ofthe control apparatus embodied therein.

In the figures, the numeral 1 designates a. room having an air inlet. at 2 and outlet at 3. The room may be provided with windows as shown at 4 through which a portion of the air introduced may escape. The air confan chamber into a mixing chamber 22, and a branch 23 from the conduit 12 serves to admit return air by way of the conduit -12, from the uoutlet 3, into the mixing chamber 22', vunder the control of a damper 24. 4

The air taken from the mixing chamber, is carried by a fan 25 through a tempering device 26 for introduction into the room through the inlet 2. This tempering device contains both a heater 27 and a cooling de- Vice 28. T hc heater is controlled by a valve 27 a. This cooling device is preferablyarranged on the countercurrent system, having a plurality of pipes so arranged in series that the fresh cooling liquid is introduced to encounter the already partly cooled air and thence passes on to-encounter the uncooled air so that the coldest air encounters the coldest cooling liquid and the incoming or warmest air encounters the almost spent cooling liquid. This makes it possiblel to utilize the cooling 'effect for the maximum economy since it permitsthe delivery of air to the room substantially at the temperature of the cooling fiuid. The cooling liquid may thence be discharged from the cooler 28. It is preferably thereafter passed through a cooler `33 directly associated with the dehydrator before going to waste or before returning for refrigeration as the case may be, as will bev hereinafter described.

The cooler 28 is'supplied with a cooling liquid by a conduit 4() under control of a three-way valve 41 which may supply liquid to the cooler, either from a natural supply through a pipe 42 or from a refrigerator 43 through a conduit 44. This refrigerator may be operated through any suitable refrigerating machinery including, for example, a

`compresser 45, a. condenser 46, and a liquid storage tank 47.

Suitable wet and dry bulb thermostats 50 and 51 may be provided in the return air duct 12 to control the o eration of the device automaticallya For ti'ie purpose of effecting a further controlover the humidity and temperature, and to obtain that control with the greatest efiiciency, there is associated with thehumidifier 15 a heater 32 in position to Warm the air as it enters the humidifier and thereby enable it to take up a greater quan tity of moisture. This heater will be particularly useful where the outside temperatures are very low. It may be controlled by a valve 32a. The dehydrator 16 is arranged to expose the air toa large surface of silica gel which has the property of-absorbing moisture from the air even at temperatures above the dewv point. In so doing, however, the latent heat of the withdrawn moisture is given out as a sensible heat, raising the temperature of the gel and of the air. There is, therefore, preferably associated with the deh drator a cooling coil 33 at the point in the system of .the maximum niediately following the dehydrator'y itself. Thisicooler can most economically be placed in series with'the cooler 28 to receive the cooling fluid which has already passed temperature, that is, im- .I

through the cooler 28, since in this manner the additional cooling effect obtained in the cooler 33l results in the discharge'of the .cooling fluid at a-higher temperature without the necessity of additional refrigeration or additional cooling fiuid.l

` The control apparatus for controllingthe temperature under the influence of the Wet and dry bulb temperatures may be Varied to meet conditions desired. For example, as illustrated in Fig. 2, the dry bulbl thermostat maybe arranged to control the flow of cold water. to the air cooler 28 by means of the valve 41, and to control the flow of steam to the air heater 27 by Ameans of the valve 27a, so that as the dry bulb temperature rises, the heat from the heater is cut off and if this proves insuflicient tof lower the temperature,

`the cool water from lthe city supply may be introduced. If this be insuflic1ent,'refrig erated water may be used. `The wet bulb thermostat may be uscd'to control the proportions of air through silica' gel cell and through the humidifier, increasing the proportions of thelatter as the wet bulb temperature falls. This wet bulb -thermostat may also be used to introduce steam into the tempering coil 32, if desired, as, for example, if the humidification from the humidifier acting upon the unheated air proves insufhcient. 1

If desired,.the dry bulb thermostat may alsobe caused to introduce large quantities of return air when ncedcd,.in order to increase the sensible heat to effect a saving in direct heating in the heater 32, and the wet bulb device may be caused to operate the damper 13 to introduce large uantities of return air through the humidi ying system in order to effect a saving in the operation ofA the heater 32. Y Since, in general, the Ventilating problem in the summer time is one. of dehumidification and requires humidification only under certain conditions' in the winter time, formertain seasons of the year, the sprays within the humidifying chamber may beclosed down and the chamber 15 itself usedsolely as abypass varound the silica gel cell. Similarly, during other seasons of the year the silica .gel may be omitted from the dehydrator and the dehydrating chamber itself used as a bypass around'the humidifier. With a system contemplating this. as its sole method of operation, the additional by-pass 17A may be omitted. Since, however, the humidifier when operated with cold water will act as a combined dehumidifier and cooler, and the silica gelcell operates as a dehumidifier and heater, it is Y bbvious that the association of the two cells and the by-pass 17 permit' an apportlonmg of the air between them which-will control not only the moisture content ofthe air but above process and in the construction setforth, which embodythe invention, may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing' shall be interpreted as illustrative and not in a limiting sense.

It is also understood that the following claims are intended to cover all of the generic and specific features of the invention herein. described, and all statements 'of the scope of the invention which, as a matter of language,

might be said to fall therebetween.

Having described. my invention, what I claim as new and desire to secure by Letters Patent is l. In combination` a chamber, a'branched conduit for conducting air to said chamber, humidifying means in 'one of said branches and dehydratingmeans in the other of said branches, a mixing chamber into which each of said branches discharges', means for conducting return air from a room to said mixing chamber, and means for adjusting the superheat of the air passing to the chamber.

2. The method of humidity control which comprises extracting moisture from a portion of 'the air above the dew point, adding j moisture to another portion of the air, mincomprises apportioning' the air betweeny a' gling both said portions with other air, and controlling the temperature and moisture content of the air by regulating the said proportions.

3.. The process of conditioning air which refrigerating dehydrator and a hygroscopic dehydrator, mixing the appointed air, and adjusting the proportions of the mixture to control both temperature and humidity.

4. The process of conditioning air which comprises dehydrating a portion thereof by refrigeration,dehydrating a portion thereof hygroscopically, mingling the two portions with. each other and with untreated air to control the temperature and humidity.

5f A method of conditioning air which includes withdrawingr air from an enclosure,

passing a certain amount of such air through a humidifier, passing another portion of the withdrawn. air throu h a dehydrator, mixing the humidified and ehydrated air, injecting a further amount of air withdrawn from the enclosure into the resultant mixture, and introducing the. complete mixture to the enclosure.

6. An apparatus of the character described including a dehydrating apparatus. cooling means arranged to the rear thereof, an 'en-v closure formed with inlet and outlet openings, means providing a passageway extending from said outlet opening and connected to the intake end of said dehydrating appa-i ratus, a by-pass in said passageway, and means providing a passageway connected to said cooling means, said by-pass, and to the intake opening of said enclosure whereby withdrawn unconditioned airis injected into the dehydrated cooled air and the resultant mixture is introduced into said enclosure.

7.- An apparatus of the character described, including a dehydrating apparatus, cooling means arranged to the rear thereof, an enclosure formed with inlet and outlet openings, means providing a passageway extending from said outlet opening and connected to the intake end of said dehydrating apparatus, a by-pass in said passageway,means providing a passageway connected to said cooling means, said by-pass and to the intake opening of saidenclosure, whereby withdrawn unconditioned air is injected into the dehydrated cooled air, and the resultant mixture is introduced into said enclosure, and

means disposed within said last named passageway for controlling the sensible heat of the air flowing through the same.

8. An apparatus of the character described including, in combination, an enclosure yformed with inlet and o'utlet openings, a pasfirst named passageway and in communication with said mixing chamber whereby to directly introduceuntreated air into the mixture of humidiiied and dehydrated air.`

9. The method of conditioning air supplied to an. enclosure which comprises dehydrating outside air, adding non-dehydrated outside air, withdrawing air from the enclosure, mixing the withdrawn air, the-dehydrated air, and the non-dehydrated outside air, and discharging the mixture into the e11-V closure. a

10. Apparatus for conditioning the .air supplied to an enclosure, comprising an air passageway connecting withoutside air and with air recirculated from said enclosure, a

duct branching o from said passageway, a dehydration chamber connecting with said duct, a second duct branching oil` from the passageway and by-passing said chamber, a third duct connecting with the output of said chamber, said second duct, and said enclosure for supplying air'from said enclosure to be mixed With the dehydrated air and the by-passed air, and a fourth duct connecting with said enclosure for conducting the air .air to said enclosure.

12. A paratus for conditioning the air supplie to an enclosure, comprising a dehydration chamber arranged to receiveoutside air, means 'for by-passing a controlled amount of outside air around said chamber to its outi put side, where it is there mixed with dehydrated air, a passageway delivering return air from said enclosure to the output side of said chamber, and a-second passageway connected with the outputpside of said chamber vfor delivering the mixed outside, dehydrated, Vand return air to said enclosure. A

13. Apparatus for conditioning the air i within an enclosureacomprising a dehydration chamber arrangedV to receive outside air1 a passageway by-passing outsideair around said chamber to its loutput side Where it is there mixed with dehydrated air, means for controlling the proportion of dehydrated air toby-passed air, a second passageway delivering return air from said enclosure tothe output side of said chamber, anda third passageway connected with the output side of said chamber for delivering mixed outside, dehydrated, and return air to said enclosure.'

14. Apparatusfor conditioning the air supplied to an enclosure, comprising adehydration chamber arranged. to' lower the moisture content and temperature of air, aA passage- Y way delivering outside air to the input side Vof said ygbamber, ducts for delivering outside air and air withdrawn from said enclosure to the output side of said chamber where it is there mixed' with the colder dehydrated air air chmber, an inlet admitting fresh air into t Saidchamber, a duct connecting with said chamber and said enclosure for supplying air recirculated from said enclosure to said chamber, a dehydration chamber connecting"k with said fresh air chamber for-dehydrating the air mixed therein, an air mixing chamber vconnecting with the output side of said dehydration chamber, a second duct connecting with said mixing chamber and said enclosure for supplying recirculated air to said mixing chamber, and a passageway connecting -with said mixing chamber and said enclosure for supplying mixed dehydrated air and recirculated air into said enclosure.

16. The combination, in .an air conditioning system, of an enclosure, means for circulating air to and from the enclosure, means for introducing fresh air into the recirculated air after it leaves the enclosure, said fresh air and recirculated air being allowed tomix, means for by-passing one part of the mixed air Without conditioning, means for conditioning the other part of the mixed air, means for tempering the mixed airprior to conditionlng of same, means forI commingling the unconditioned. and conditloned air, means for tempering saidfmixture, andfmeans-'for rey air to the enclosure.

WALTER L. FLEISHER.

turning the to raise the sensible heat thereof, and a s ec- A l paratus for conditioning the Yair Y

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