US2405812A - Air conditioning - Google Patents

Description

Aug. I3, I%% T. w. BINDER AIR CONDITIONING Filed May 30, 1944 s sheets-sheet 1 v INVENTOR Thomas "(Binder I BY 1 I djZm M r ATTORN Aug. 13, 1946. T. w. BINDER AIR CONDITIONING Filed May 30, 1944 3 Sheefis-Sheet 2 Z wa mm @M Ei rO N W Y 8B./ a m w 6 Aug. 13, 1946.

T. W. BINDER AIR CONDITIONING Filed May 30, 1944 s Sheets-Shet' 3 INVENTOR Thomas Wfiindei Patented Aug. 13, 1946 UNITED STATES PATENT OFFICE AIR CONDITIONING Thomas W. Binder, Maplewood, N. J.

Application May 30, 1944, Serial No. 538,042

Claims. (01. 62-129) This invention relates to air conditioning, and, more particularly, to controlling humidity by causing excess moisture to pass from the air into a low pressure zone where the moisture is condensed; thus the air is brought to the proper humidity without excessive cooling of the air.

An object of this invention is to provide for continuously controlling the humidity of air without necessarily changing th temperature of the air. A further object is to provide a method and apparatus for removing moisture from the air with a minimum of expense and in a manner which is suitable for use under varying conditions met with in this art. A further object is to provide for the removal of latent heat from air without necessarily removing sensible heat. A further object is to provide apparatus of the above character which is practical and sturdy in construction and which is inexpensive to manufacture and operate. A still further object is to provide for condensing moisture from air by causing the moisture to pass to a condensing zone without passing the air through the zone. These and other objects will be in part obvious and in part pointed out below.

The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts and in the several steps and relation and order to each of the sam to one or more of the others, all as will be illustratively described herein, and the scope of the application of which will be indicated in the following claims.

In the drawings in which are shown three of the several embodiments of the invention:

Figure 1 is a perspective View of one embodiment of the invention with parts broken away and with certain of the apparatus represented schematically Figure 2 is a vertical section of the dehumidifying unit of Figure 1;

Figure 3 is a perspective view of the dehumidifying unit of another embodiment of the invention;

Figure 4. is a side elevation, partially schematic, showing one manner of using the unit of Figure 3;

Figure 5 is a sectional view on the line 5-5 of Figure 4;

Figure 6 is a view similar to Figure 4 but showing another embodiment of the invention; and

Figure '7 is a plan View of the dehumidifying unit of Figure 6.

As conducive to a clearer understanding of the invention, the problems involved in connection with the illustrative embodiments of the inven- 2 tion will be discussed. The term air conditioning has been loosely applied to many methods of treating air but it is more commonly applied to applications where air is cooled and its humidity is regulated. Even though it is recognized that humidity is a very important factor in obtaining comfort, far too little emphasis has been given to humidity control. In practice it is known that the average person is comfortable even though the temperature and humidity vary over a rather wide range. However, the humidity and temperature should be considered together in order to stay within the comfort zone; that is, a rather high temperature will appear comfortable to the average person if the humidity is low, whereas a much lower temperature will appear uncomfortable at high humidity.

As the temperature rises in a room where there are people, the evaporation of perspiration and the expelled vapor causes a rise in humidity, and in order to maintain a condition of comfort the moisture should be removed from the air; it is true that cooling alone will give some temporary relief but the moisture must be removed if continued comfort is desired. In the past, temperature and humidity have been considered together and it has been conventional with some systems to simultaneously cool air and dehumidify it by passing it into direct contact with cold surfaces or liquids.

The heat removed in treating air in this manner is the latent heat of condensation of the moisture and the sensible heat. In the past it has be n considered necessary to remove the sensible heat in order to remove the latent heat; this is on the basis that the latent heat is removed only by bringing the temperature of the air down below the dew point. In the average installation the removal of the sensible heat constitutes approximately of the refrigeration load and the removal of latent heat constitutes the other 25% of th load. Thus, when no air cooling effect is desired and moisture removal is the entire problem, the unit is really only 25% efficient because 75% of the cooling effect is for the purpose of removing sensible heat and steps must be taken to reheat the air up to the desired temperature. Furthermore, these systems are not flexible in their use because each unit must be engineered, constructed and operated to solve the particular problem at hand. This has been a serious handicap in the field of air conditioning because it interferes with the mass production of air conditioning units. In addition to this, the many varying conditions of operation cause many air con-,

3 ditioning systems to be unsatisfactory for a large part of the time.

In actual practice, the main emphasis in air conditioning has been placed upon the cooling of the air and the problem of obtaining proper humidity has been considered secondary or even ignored completely. For example, with some systems air is passed into direct contact with cooling coils with the result that the air is cooled to a very low temperature and moisture is condensed onto the coils. With some of these systems a relatively small stream of air is cooled to a temperature far below that which is acceptable for use and this small stream of air is either blown directly into the air conditioned space or it is mixed with a stream of warm, humid air. With this type of system the air may be maintained at a desired temperature, but there is no real control on the humidity; the only way to really reduce the humidity is to cool more air or to reduce the temperature of the stream of air being cooled. Thus, when there is an excessive humidity load the temperature may be within an acceptable range but the humidity may be too high, or the humidity may be reduced to a satisfactory level only by reducing the temperature below that desired.

Air conditioning systems are in use wherein the air is cooled, washed and reheated with the result that air of a desired temperature and somewhat near an acceptable humidity is delivered. However, these systems are complicated and involve the use of large and expensive equipment and air ducts. Furthermore, these systems operate upon the principle referred to above of expending approximately 75% of the cooling effect in cooling the air and the other 25% in dehumidifying the air. This ratio between the two eifects is satisfactory for some loads, particularly where the load does not vary, but in most installations this ratio between the loads is unsatisfactory and the load varies over av wide range. The variations in the load may take the form of a rapid rise or fall in the relative humidity or temperature, or both.

Another factor which is important in considering the field of air conditioning is the variation in the efficiency of the refrigeration unit itself. When air is used for cooling the condenser of the refrigeration system the minimum cooling eifect F on the condenser is apt to occur at th time of the maximum refrigeration load so that the efiioiency of the refrigeration system fails when the load rises. Water is used for condenser cooling, but in some cities the public water system has been so overloaded by such use that steps have been taken to curtail this us of the water. In all cases Where refrigeration systems are used in connection with air conditioning the condenser cooling problem is a serious one, and it is aggravated by the extra load of removing all of the ensible heat when it is desirable to remove only latent heat and perhaps part of the sensible heat. That is, the inefficient air conditioning apparatus places an excessive load upon the cooling system for the condenser so that the system is'apt to be ineffective under maximum load conditions, and the refrigerating system might even break down completely.

Attempts have been made to meet this problem by providing more careful control upon the apparatus and by providing larger and more complicated air duct systems. Howeven'even with these complicated systems the problem of remov ing heat from the air has not been divorced from 4 the problem of dehumidifying the air. It is an object of the present invention to provide a solution to the above problems with a simple system wherein the temperature and humidity of the air are controlled independently. By doing this primary consideration may be given to the control of the humidity so that moisture can be removed from the air without any substantial cooling of the air. Furthermore, with the illustrative systems the air may be dehumidified and cooled with the same apparatus that is used for dehumidifying the air and yet complicated controls are unnecessary.

In the illustrative embodiments of the invention the moisture is removed from the air by creating a low vapor-pressure zone to which the moisture passes and in which it is condensed. This low vapor-pressure zone is produced in a refrigerated cold chamber where the air is more or less stratified, and the moisture enters this Stratified air due to the low vapor-pressure condition. The cold chamber has an opening or a number of openings through which the moisture passes from the high-humidity, warm air to the low vapor-pressure stratified air in the cold chamber but the air which is being dehumidifiecl does not pass through the cold chamber. The cold chamber may be positioned within the air conditioned chamber, or it may be positioned outside the air conditioned chamber and connected thereto by air ducts through which air is directed by a suitable fan. The air is passed in a stream along the side of the cold chamber and the moisture leaves the warm air and passes into the cold chamber. In the accompanying drawings, the cold chambers and the air ducts associated therewith are shown broken away and the remaining structure is represented schematically on a reduced scale.

In the embodiment of Figures 1 and 2 the only substantial effect which is desired is the dehumidifying of the air and this effect is obtained by passing the air through a dehumidifying unit. Referring to Figure 1, this dehumidifying unit is represented at 2 and includes a horizontally disposed casing 4. Casing 4 (see also Figure 2) has atop wall 6 and a bottom wall 8 and end walls l0. A perforated wall l2 having perforations ll therein is positioned between walls 6 and B and parallel thereto, and along the sides of the casing are two side walls [4 (Figure 1) extending between wall 8 and wall l2. Thus, a cold chamber i3 is formed beneath the perforated wall 12, which is closed except for the perforations II in wall l2, and a flat horizontal air passageway l 5 is formed above this perforated wall. Within cold chamber I3 is a finned evaporator l6 formed by a coil ll having fins I 8 thereon.

Evaporator I6 is supported adjacent the ends of the casing by flanged plates 20 on coil I! which are vertically disposed between walls 8 and I2. Evaporator I6 is held out of contact with the casing walls with the result that there is very little heat transfer through the walls to the evaporator. Liquid refrigerant is supplied to evaporator l6 through a pipe 22 and the gas refrigerant is withdrawn through a pipe 24 by a compressor, represented schematically 'at 26 and driven by a motor 28. The compressed refrigerant is passed to a condenser 30 where it is condensed and flows to a receiver 32. I

Air is directed through the horizontal passageway [5 by a fan 34 driven by a motor 36. This air moves along the passageway past the perforations 1 I in wall l2 in a thin sheet. Within chamber 13 evaporator 16 cools the vapor and causes it to condense so that a low vapor-pressure zone is created within the chamber. However, there is no substantial circulation of air and the air tends to become stratified. Assuming that the air flowing through passageway I5 contains a large amount of moisture, this moisture will tend to pass to the low vapor-pressure zone in chamber l3 and perforations H are of suflicient size and number to permit this movement of the vapor. However, wall 12 confines the flow of air to the passageway so that the stratification of the air in chamber I3 is not disturbed.

The moisture which is condensed on evaporator l6 drips from the condenser and flows from the bottom of casing 4 through a drain pipe 38. As indicated above, evaporator 16 is held from contact with casing 4 so that there is no substantial cooling of air by contact of the air with the casing. When desired, the casing is insulated, and perforated wall I2 is made of a material which is a poor heat conductor. However, in the present embodiment this heat transfer is not appreciable and casing 4 is made of sheet metal.

In the embodiment of Figures 3, 4 and 5 the dehumidification unit is similar to that of the embodiment of Figures 1 and 2 except that the cold chamber extends vertically and it has two perforated side walls along which the air passes for dehumidification. Furthermore the system is arranged in such a manner that the temperature and humidity are both controlled automatically. Referring particularly to Figure 3 the evaporator l6, formed by a coil i1 and having fins I8 thereon, is positioned in a chamber it having two perforated side walls 52 and 4d (see also Figure 5) with perforations 43 therein. Coil l! receives refrigerant at the top-through a pipe 22 and gas is withdrawn at the bottom through a pipe 25 by a refrigeration system of the type schematically shown in Figure 1 and explained above. Chamber at is formed in a casing having end walls 86 and 48 and side walls 59 and 52. The top of chamber 49 is closed by a top wall 54 and the bottom is closed by a bottom wall 56.

Positioned intermediately between perforated wall 42 and side wall 58 is a partition 58, and similarly, between perforated wall M and side wall 52 is a partition 68. These partitions form a pair of outer passageways 62 and 64 through which the unconditioned incoming air passes conditioned chamber.

downwardly, and a pair of passageways 66 and 68 through which the outgoing air passes outwardly along the perforated walls 52 and 44, respectively. At their lower ends passageways t2 and 64 are joined by a duct lil (see also Figure l); similarly passageways 66 and 68 receive air from a common duct 12. passes into the spray chamber M of a unit 75; in chamber M the air is subjected to the action of a spray it. The spray T6 washes the air, and the excess water falls to a sump at 18. If the air which enters the unit is exceedingly dry a large amount of water is evaporated into the air with the result that the air is cooled. However, if the air is quite moist the action will be mainly that of washing the air.

The air passes from the right-hand side of chamber M into chamber 82 through a filter 80 which removes the unvaporized moisture from the air along with particles of dirt which tend to pass with the air. The clean, moist air is withdrawn from the top of chamber 82 by centrifugal fan 84 and is directed through duct 72 upwardly The air from duct ill through passageways 66 and 68 (Figure 5); In moving upwardly the air is subjected to the same action as that to which the air is subjected in the embodiment of Figures 1 and 2 in passing through passageway 15. from the air passes through the perforations E3 in walls 42 and 4d and is condensed on evaporator [6 in cold chamber 40. The condensed moisture flows from chamber d0 through a drain pipe 86 shown best in Figure 4.

With this embodiment, substantially saturated air or at least air of a predetermined relative humidity flows through duct 12 into the passageways 66 and G8. The rate of movement of air upwardly through passageways 68 and 63 is such that air of the desired humidity is delivered into the air- By changing the rate at which the air moves upwardly through passageways 65 and t3 the dehumidification eifect of the unit is changed; that is, by increasing the rate of movement of air, the dehumidifying effect upon the air is reduced, and by slowing down the rate of movement of air this effect is increased. In addition to this control the dehumidifying efiect is increased by'maintaining evaporator It at a lower temperature. In this way the moisture is condensed more readily and the low vapor-pressure zone tends to draw more moisture from the two streams of air. Under some circumstances it may be desirable to have no dehumidification effect in which event the refrigeration system supplying the refrigerant to evaporator 56 is stopped. The air which passes from the top of passageways 6t and 53 is directed by means (not shown) to the desired portion of the air-conditioned chamber. Similarly air is directed into the top of passageways B2 and 64 by means not shown.

In the embodiment of Figures 6 and 7 the system is generally similar to the embodiment of Figures 2, 3 and 5. However, the dehumidifying unit is cylindrical and includes an outer cylindrical casing 83 which encloses concentric perforated cylinder 95, having perforations 92 therein, and a concentric cylindrical baffl 94. The cold chamber is formed between casing 83 and cylinder iii and is indicated at $53. Within cold chamber 96 is a helical coil E53 which receives liquid refrigerant at the top and from which gas refrigerant is withdrawn in the manner explained above in connection with Figure l. The incoming air passes downwardly through the cylindrical bafile 9 and is delivered by a duct 589 to a unit l5 where the air is subjected to the treatment as explained above in connection with Figure 4.

The humidified, clean, filtered air is withdrawn by centrifugal fan 8 and directed b a duct M2 to the annular passageway I'M between the outer wall of cylindrical baflie 9d and the perforated cylinder 92. In passing upwardly through passagewa HM the air is subject t the same treatment as the air received in the dehumidifying unit of Figures 3, e, and 5. The outgoing air is treated as explained above in connection with the embodiment of Figures 3, 4, and 5. The water condensed on coil 93 is drained from the bottom of chamber through a drain pipe H36.

As many possible embodiments may be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinabove set forth, or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Accordingly, moisture I claim:

1. In the art of air conditioning, cooling a body of air with the result that the vapor therein is condensed and a low vapor-pressure zone is created, passing the air to be conditioned along a path adjacent said zone, and independently washing and cleaning the air before it passes said zone.

2. In apparatus of the character described for removing vapor from air, the combination of, a substantially rectangular casing, duct means forming a substantially thin passageway for the air through said casing from one side thereof to the other, said duct means having as one wall a perforated sheet, a cold chamber Within said casing and separated from said passageway by said perforated sheet, and means to cool the air in said chamber whereby a low vapor-pressure area is created within said cold chamber with the result that vapor passes from the air in said passageway into said cold chamber where it is condensed.

3. In apparatus of the character described for removing vapor from air, the combination of, means forming a casing which is substantially closed but which has an air inlet and an air outlet connected by' an air passageway whereby air passes into said casing through said air inlet and is discharged from said casing through said air outlet, said casing having a cold chamber which is separated from said passageway by wall means which is provided with an opening through which gases may pass freely, and means to cool the air in said cold chamber to a temperature suiliciently low to condense moisture thereby to create a low vapor-pressure area within said old chamber with the result that vapor passes from the air in said passageway into said cold chamber by the difference in the vapor partial pressures.

4. In apparatus for removing vapor from air, the combination of, means forming a casing having an inlet opening and an outlet opening, wall means within said casing forming a chamber and a passageway connecting said air inlet opening to said outlet opening, said chamber being connected to said passageway through one or more openings, and means within said chamber to condense vapor thereby to create a low vapor-pressure zone within said chamber whereby vapor passes from said passageway to said chamber by the difierence in the partial pressures of the vapor.

5. In apparatus of the character described for removing vapor from air, the combination of, wall mean forming a substantially rectangular casing having an air inlet opening and an air outlet opening, partition means forming within said casing an air passageway from said air inlet opening to said air outlet opening and also forming a cold chamber which is open to said passageway at a plurality of openings spaced along said passageway, refrigerating means to cool the air in said cold chamber whereby the vapor is condensed and a low vapor-pressure zone is created within said cold chamber with the result that vapor passes from the air in said passageway into said cold chamber where it is condensed, and means to direct a stream of air through said passageway.

6. In apparatus for removing vapor from air, the combination of, wall means forming an enclosure having an air inlet opening and an air outlet opening and a passageway connecting said openings, said wall means also defining a cold chamber which is connected to said passageway through one or more vapor openings, and means within said cold chamber to cool the air therein below the dew point whereby vapor is condensed and a low vapor-pressure zone i created with the result that vapor passes from said passageway into said chamber through said one or more vapor openings due to the difference in the partial pressures of the vapor.

7. In apparatus for removing vapor from air, the combination of, wall means forming an enclosure having a pair of air inlet openings and a pair of air outlet openings and a pair of passageways connecting said openings, said wall means also defining a cold chamber which is positioned between said passageways and is connected to said passageways through a plurality of vapor openings, and means within said chamber to cool the air therein below the dew point whereby vapor is condensed and a low vapor-pressure zone is created with the result that vapor passes from said passageways into said chamber through said vapor openings due to the difierence in the partial pressures of the vapor.

8. In apparatus for removing vapor from air, the combination of, wall means forming a cylindrical enclosure having an air inlet opening and an air outlet opening and a passageway connect ing said openings, said wall means also definin a cylindrical cold chamber which encloses said passageway and is connected t said passageway through one or more vapor openings, and means withinsaid cold chamber to cool the air therein below the dew point whereby vapor is condensed and a low vapor-pressure zone is created with the result that vapor passes from said passageway into said chamber through said one or more openings due to the difference in the partial pressures of the vapor.

'9. In apparatus of the character described for removing vapor from air, the combination of, wall means forming a casing having a passageway therethrough which connects an air inlet opening and an air outlet opening whereby air may be directed in a stream along said passageway, said wall means also forming Within said casing a cold chamber having an opening at one side to said passageway with the opening being in a plane parallel to the normal flow of air along said passageway whereby the air flowin along said passageway passes into contact with th air in said chamber without passing through said chamber, and refrigerating means to cool the air in said cold chamber below the dew point whereby vapor is condensed and a low vapor-pressure zone is created within the cold chamber with the result that when relatively warm air having vapor therein flows along said passageway the vapor tends to flow from the stream of air into said cold chamber where it is condensed.

10. Apparatus as described in claim 9 which includes air-washing means, air-filter means, wall means forming a heat-exchange passageway positioned in heat-exchange relationship with the first-named passageway, and means to pass the air-successively through said heat-exchange passageway and said air-washin means and thence through said air-filter means to said air inlet opening.

11. Apparatus as described in claim 9 which includes means forming a heat-exchange passageway through which the air flows to said air inlet opening in counter-current heat-exchange relationship with respect to the air passing through the first-named passageway.

12. In the art of air conditioning, the steps of, cooling a body of air to a temperature below its dew point with the result that vapor therein path in contact with said body of air at one side of said zone with the air in the stream being open to the body of air for th free flow of vapor from the stream of air to the body of air and with the air in the stream flowing parallel to said side of the zone whereby the Stratified condition of the air is not disturbed materially.

13. In the art of air conditioning, the step of, cooling a body of air to a temperature below its dew point with the result that vapor therein is condensed and a low vapor-pressur zone is created within which zone the air is relatively cold and relatively stratified, and passing two streams of relatively warm air having vapor therein along paths in contact with the opposite sides of said body of air at the sides of said Zone with the air in the streams being open to the body of air for the free flow of vapor from the streams of air to the body of air and with the air in the streams flowing parallel to said sides of the zone whereby the stratified condition of the air is not disturbed materially.

14. In the art of controlling the humidity of air, the steps of, cooling a bod of air to a predetermined temperature below its dew point with the result that water vapor therein is condensed and a low vapor-pressure zone is created within which zone the air is maintained at said predetermined temperature and is relatively stratified, and passing a stream of relatively humid air the temperature of which is substantially above said predetermined temperature along a path in contact with said body of air at one side of said zone, the path being open to the zone for the free flow of Water vapor from the stream of air to the body of air and the air in the stream flowing parallel to said side of the zone, whereby the Stratified condition of the air is not disturbed materially and whereby the temperature of the air in said stream is maintained substantially above said predetermined temperature.

15. In apparatus for removing water vapor from air thereby to control the relative humidity of the air in a room or the like without an accompanying material change in the temperature of said air, the combination of, wall means forming an enclosure having an air inlet opening and an air outlet opening and forming a pair of parallel spaced passageways connecting said openings, said wall means also defining a cold chamber which is positioned between said passageways and is connected to each of said passageways through one or more openings with said passageways being relatively thin transversely of the direction of flow of the air whereby all of the air in said passageways flows relatively close to said openings, heatexchange means within said cold chamber to cool the air therein below the dew point whereby water vapor is condensed and a low vapor-pressure zone is created within said cold chamber with the result that water vapor passes from said passageways into said cold chamber through said vapor openings due to the partial pressures of the water vapor, and an electric fan to direct air from said inlet opening and along said passageways and thence through said outlet opening and to said room or the like.

THOMAS W. BINDER.

Images