US2390104A - Cooling and dehydrating apparatus - Google Patents

Description

N A M F u A K H COOLING AND DEHYDRATING APPARATUS I Filed Feb. 23, 1942 2 Sheets-Sheet l INVENTOR. [41km M KW HTTOENEYS cc. 4, 1945. H. J. KAUFMAN COOLING AND DEHYDRATING APPARATUS Filed Feb. 23, 1942 2 Sheets-Sheet 2 Fla. /5

f ATTORNEYS E- Patented Dec. 4, 1945 UNITED STATES V'PATENT OFFICE COOLING AND DEHYDRATING APPARATUS Hiram Joseph Kaufman, Detroit, Mich. Application February 23, 1942, Serial No. 432,014

4 Claims. (01. 183-43) The present invention relates to cooling and dehydrating apparatus, in which crushed or broken ice and calcium chloride or other suitable hygroscopic material are used to cool and dehydrate air and gases.

One of the objects of the invention is to provide a simple and inexpensive cabinet and apparatus for cooling, dehydrating and purifying the air of rooms with a minimum addition of fresh air so as to reduce operating costs.

Another object of the invention is to provide 7 an improved portable cabinet for conditioning the air of hotel rooms, mortuaries and other intermittent comfort cooling enclosures.

A further object of the invention is to provide a simple cabinet and apparatus which involves crushed or broken ice for cooling and calcium chloride or other suitable hygroscopic material for cooling and dehydrating air in two separate stages.

A still further object of the invention "is to provide improved apparatus for automatically preventing the temperature or humidity 01' the air of an enclosure from going above predetermined limits.

A further object is to provide an improved crushed ice cabinet for air conditioning in which condensation is avoided and economical consumption of ice is obtained.

A further object is to provide an improved cabinet and apparatus for economical air conditioning through the use of ice and a deliquescent chemical wherein the ice is primarily consumed in removing sensible heat from the air for cooling.

Another object is to provide a portable cabinet of the type described having improved antisplash provisions.

Another object resides in an improved apparatus wherein moisture is removed from the air to convert the latent heat of the air into sensible heat for removal at temperatures above the dew point of the air.

These and other objects and advantages residing in the combination, construction and arrangement of the parts will more fully appear from a considerationof the following description and annexed claims.

In the accompanying drawings wherein one form of the present invention is illustrated,

Fig. 1 is a longitudinal section of an improved cooling and dehydrating cabinet capable of carrying out the present invention,

Fig. 2 is a transverse section of a cooling and dehydrating cabinet, taken on line 11-11 oi. Fig. 1,

Fig. 3 is a transverse section of a dehydrator unit. in the cabinet, taken on line III-III of Fig. 1,

Fig. 4 is an end elevation of the screen wire partitions of the dehydrator unit,

Fig. 5 is an elevation of the screen wire partitions forming one side of one of the chemical containers,

Fig. 6 is an elevation of the wire screen partition forming another side of one of the chemical containers,

' Fig. '7 is an end elevation or the wire screen partition shown in Fig. 6,

Fig. 8 is a plan view of the wire,screen partition shown in Fig. 5,

Fig. 9 is a plan view of the wire screen partition shown in Fig. 6, I

Fig. 10 is a plan view of the rack for supporting the wire screen partitions,

Fig. 11 is an end elevation of a support for the dehydrator trays,

Fig. 12 is a side elevation of the support shown in Fig. 11,

Fig. 13 is a section of the indents or separators used in connection with the wire screen partitions, trays, and splash screen,

Fig. 14 is a section of the indent or separator used in connection with the partition as shown in Fig. 9,

Figs. 15, 16, 17 and 18 are plan views of tray constructions used in the dehydrator.-

Referring specifically to Figs. 1 and 2. the cabinet 30 with theair inlet 3| in. the bottom. the removable cover 32, with the air outlet grille 33 and the removable hatch cover -34 with the handles 35, is made portable by means of the casters 36. The cabinet 30 has the ice containers 3! with the bottoms 38 having the holes 39, the sides 40 having the insulation 4| and the cover 42 with the insulation 43 and the lifting handles .44. The ice containers 3! are separated from each other by the air passages 45 and 46 and from the case 30 by the air passa- cs 41, 48, 49 v and 50. The ice containers 3'! are filled with pieces of broken or crushed ice 5| by lifting the hatch cover 34 and the ice container cover 42.

The trays 52 and 53 are underneath the ice containers and are supported on each other by the indents or separators 54. The lowest tray 53 is attached to the sides of the waste ice water tank 55. The ice water 58, formed by the melting of the ice 5! in the containers 31, drains through the holes 39 in the bottoms 38 onto the tray 52 and across the trays 52. and 59, in series and in opposite directions, draining from one tray to another through the holes 51.

The lower tray 59 has an extension 59 and which together cover the top of the waste water tank 55, thereby sealing the waste water from contact with the air stream to prevent the evaporation of water into the air stream due to its temperature being above that of the dew point temperature of the air in contact therewith. The waste water tank 55 has the overflow or normal drain pipe 59 for draining the warmest water from the top of the tank and the emptying drain pipe 60 which is controlled by the valve The raft 52 floats on the surface of the waste water 56 in the waste water tank 55, is loosely fitted at the sides, has the large drain holes 53 and has the wire splash screen 64 supported above and attached to the raft 62 by the indentsor separators 54'. The ends and sides of the raft 02 are prevented from rising above a predetermined level by the clip angles 56 which are attached to the sides and ends of the tank 55. The purpose of the raft 62 is to prevent splashing of the waste water 55 in the tank 55 when moving the cabinet 30 on the casters 35. The

purpose of the splash screen 64 is to prevent the splashing of and to reduce the noise of the waste water 56 dripping through the holes 51 of the tray 53 into the tank 55.

The cabinet 30 also contains the dehydrator case 61, a transverse section of which, taken on the line IIIIII, is shown in Fig. 3. The case 51 has the cover 58 to which is attached the lifting handle 69, the sides having the air outlets 10, individually controlled by the dampers 1| and held in predetermined positions by the friction hinges 12. The case 61 contains the wire screens 13 and 14 as shown in Fig. 3, which hold the calcium chloride flakes in the vertical baskets 16, which are separated by the air passages 11. The thickness of the air passages 11 is determined by the indents 54" and the thickness of the calcium chloride baskets 16 is determined by the indents or separators 19. The sides of the case 51 are bent in at the bottom to form ledges which support the perforated trays 80 and 8| and the rack 82 by means of the supports 83. The calcium chlcgide baskets 15 are supported on the rack 02. The height of the supports 83 which determine the vertical spacing of the perforated trays 80 and 8| and the rack 82 is such that the velocity of the horizontally moving air between the trays and rack is equal to that of the vertically moving air through the holes 85 in the trays. The friction loss of drawing air through the perforated trays is kept at a minimum by keeping the velocity of the air constant.

The calcium chloride solution' formed by the melting of the calcium chloride flakes 15 in the baskets 15 flows down through the openings 84 in the rack 82 and then downward through the holes 85 in the perforated trays 80 and BI, and drips onto and through the splash screen 86 and through the holes 51 in the waste water tank,

cover 59 and into the waste water tank 55, where it is sealed off from further contact with the air stream in order to prevent evaporation of water from the solution when the vapor pressure .of the air is lowered below that of the waste solution. The holes 85 in the perforated trays 80 and 0| are staggered over each other so that the calcium chloride solution has to flow downward through and over the surfaces of the perforated trays 80 and 8| in a zigzag direction. The

splash screen 90 is supported above and attached to the waste water tank cover 59 by the indent: 54, formed in the splash screen 05. V

The cabinet 39 is divided into four horizontal air passages by the partitions 01, 00, 09, 90 and 9|, in which the air is cooled in stages in contact with the cooling surfaces of progressively lowering temperatures. The air is drawn into the cabinet through the air inlet 3|, through the air passages 92, 99 and 94, around the waste water tank in indirect contact with the waste water, then between the trays 52 and 59 in direct and indirect contact with the ice water and into the space 95, from which one portion of the air is drawn through the air passages l5, 41, ll, 45. 49 and 50 in indirect contact with the crushed ice and into the space 96 by the fan 91.

The other portion of the air is drawn from the space 95, upward through the holes 05 of the perforated trays 80 and 9 I, then through the holes 94 of the rack 82, in a zigzag direction, in a counter flow direction and in contact with the calcium chloride solution, then upwardly through the air passages I1 in contact with and calcium chloride flakes 15, then through the air outlets 10 of the dehydrator case 01, controlled by the dampers H and into the space 96 by the fan 91.

Air is drawn from the space 95 and discharged from the cabinet 30 through the air outlet grille 33 by the fan 91, revolving in the throat 99 and driven by the motor 99, which is attached by the bolts I00 and the nuts IOI to the bracket I02, which is attached to the underside of the cover 32.

Electric power is supplied by the wires I03, I04,- I05 and I09, controlled by the switch I05,

the thermostat I01 and the humidostat I00 to operate the motor 99. In case the temperature of the air surrounding the thermostat I01 goes above the predetermined degree for which the thermostat I01 is set, electric power is supplied through the wires I03, I04 and I09 to operate the motor 99 to drive the fan 91. In case the humidity of the air surrounding the humidostat I08 goes above the predetermined degree for which the humidostat I09 is set, electric power is supplied through the wires I03, I05 and I09 to operate the motor 99 to drive the fan 91. The thermostat I01 may be of conventional dry bulb or it may be of a compensating type operating in terms of effective temperature and responsive to variations in relative humidity.

The screens I I0 are laid in their spaces loosely and are forthe purpose of restricting the air flow between' and around the ice containers 31.

The proportionate amount of air drawn through the dehydrator case 51 is decreased by closing the dampers H and removing a portion of the loose screens H0, and increased by opening the dampers TI and adding a portion of the screens IIO.

The air flow is evenly distributed through the two sides of the air passages 11 of the dehydrator case 61 by individually adjusting the dampers 1|.

An effective temperature thermostat can be 0 substituted for the thermostat and humidostat tive temperature above that for which th effective temperature thermostat is set. Physical comfort is determined by the effective temperature which is a function of dry bulb temperature and relative humidity, which is raised by increasing either 'factor and lowered by decreasing either factor. It can be kept constant by decreasing either factor and increasing the other factor a proportional degree. The dry bulb temperature of the air which is discharged from the cabinet can be kept at a higher temperature, which is more comfortable, and still maintain the same efiective temperature if the relative humidity has been lowered sufllciently.

Conditioning air in two separate stages of dehydration and cooling provides for producing the same eifective temperature with a lowered relative humidity.

When dehydration and cooling are accomplished in one stage, the air must be cooled below the dew point temperature in order to remove moisture by removing latent heat. When removing moisture from air by chemical dehydration,

latent heat is converted into sensible heat and can be removed at higher temperatures and at temperatures above that of the dew point of the air. This provide for higher temperature cooling surfaces than when removing latent heat by cooling, and allows the ice water to be wasted at a higher temperature, thereby absorbing more heat units per poundof ice water, which conserves the amount of ice required for the same work.

The purpose of cooling the air before dehydration is to increase the relative humidity by lowering the temperature with little or no change in the absolute humidity, in order to increase the amount of water absorbed per unit' of calcium chloride which increases and decreases with relative humidity as shown by the following table, which is based upon the calcium chloride solution absorbing moisture from air until the vapor pressure of the solution is equal to that of the air in contact therewith, at a temperature of '77 degrees Fahrenheit. This equalization of vapor pressures between the solution and the air can be attained with a properly designed apparatus.

Relative humidity of the air Pounds oi water absorbed per pound of calcium chloride 0.80 1.00 1. 60 2. 70

In order to remove one pound of moisture from air, saturated with moisture, by condensation, it is necessary to absorb approximately 1050 B. t. u. of latent heat. It is also necessary to remove suilicient sensible heat to cool the air to saturation temperature. The heat of fusion of ice is approximately 144 B. t. u. About twenty pounds of ice are required to remove one pound tion to cooling and for economical operation by using ice for sensible cooling and calcium chloride for dehydration of the air.

The ice containers are insulated so that the 5 surfaces in contact with the air will not have a temperature low enough to cool the air below dew point temperature. The melting rate oi the ice is proportional to the rate at which sensible heat is being removed and at a comparatively higher temperature, thereby conserving ice.

The containers are separated from the sides and top of the cabinet so that the temperature of the outer surfaces of the cabinet will not be cooled below the dew point, or saturation temperature, of the surrounding atmosphere in or. der to prevent condensation of moisture on the exterior of the cabinet.

Room type cabinets, when used for air conditioning occupied enclosures with recirculated air, require the addition of fresh air to counteract the efiect of the occupants and the cooling apparatus in order to maintain comfortable conditions. This addition of fresh air increases the cooling and dehydrating load and should be kept at a minimum for economical operation. It also requires a connection to a fresh air supply which is both inconvenient and expensive in many cases.

The present invention is intended to reduce or eliminate the need for fresh air in occupied enclosures by purifying the recirculated air instead of diluting it with fresh air to counteract the effect of the occupants and the cooling apparatus.

The freshness of the recirculated air of occupied enclosures, when cooled with ice or other means, can be improved by chemically dehydrating all or a portion of the air by contact with calcium chloride flakes or calcium chloride solution.

As will be apparent, the air passing through the dehydrator unit passes between the vertical wire trays containing the chemical and out the sides of the unit adjacent the top. By avoiding the passage of the air through screens Or other finely perforated structure, the frictional loss is negligible. This permits a simple disc type fan in lieu of a centrifugal fan or the like being used and makes possible substantially constant air velocity being obtained throughout the entirecab- 0 inet. When the air is compelled to pass through finely perforated areas with which the chemical contacts, after a short time corrosion materially increases the frictional losses and the velocity of the air through the dehydrator is materially reduced. With the arrangement disclosed, long periods of use do not result in any material increases in frictional losses of the flow of air through the cabinet. Accordingly, the operation of the apparatus remains substantially 6 uniform.

Having thus described my invention, what I desire to secure by Letters Patent and claim is: 1. Apparatus for conditioning the air in an enclosed spaced by recirculation of air through the apparatus comprising a casing having an air inlet in the lower part thereof and having an air outlet in the upper part, means within the casing for forcing circulation of a stream of air from the space into the casing through the inlet opening and discharging the stream through the outlet opening, an ice container within the oasing having openings for dripping discharge ofwater from melting ice, partition structure near the intake opening directing the air drawn into 7D the casing through said intake opening through the dripping ice water, a dehydrant container for hygroscopic material within the casing, and partition walls within the casing dividing the air stream after passingthrough the dripping ice water and directing one division through the ice container in heat exchange relation with the ice in the container and the other division through the dehydrant container in contact with the hygroscopic material in the course flow oi the air to the discharge opening. v

2. Apparatus for cooling and dehydrating the air in an enclosed space by recirculation of the room air through the apparatus comprising a case having an air inlet in the lower part thereof and having an air outlet in the upper part, means for forcing circulation oi. a stream 01' air from the room into the casing through the inlet opening and discharging the stream of air through the outlet opening, an ice container within the casing having walled air passages therethrough and having openings for dripping discharge of water from melting ice, partition structure near the intake opening directing the air drawn into the casing through the dripping ice water, said ice container having heat exchange walls thereof provided with insulation, a dehydrant container for hygroscopic material within the casing having air passages therethrough, and partition walls within the casing dividing the air stream after passing through the dripping ice water and directing one division through the passages of the ice container in heat exchange relation with the insulated walls and the other division through the dehydrant container in contact with the hygroscopic material in the course of flow of the air to the discharge opening.

-3. Apparatus for conditioning the air in an enclosed space by recirculation of the air through the apparatus comprising a cabinet to be placed in the space having an air inlet at the bottom and chair outlet at the top, an ice container at one side in the upper part of the cabinet provided with transverse air passages and having drip holes through the bottom, a series of separated trays disposed transversely beneath the scopic material disposed at the opposite side within the upper part of the cabinet air stream circulating means within the cabinet to draw a stream of air through the inlet opening and discharge the air through the outlet opening, parti- 5 tion means directing the stream of air from the inlet opening transversely through the trays, and partition structure dividing the air stream to cause flow of a part of the air through the dehydrator case in contact with the hygroscopic material and the remaining portion of the air through the air passages of the ice container in heat exchange relation with the icein the container to then be discharged through the outlet opening.

4. Apparatus for conditioning the air in an enclosed space by recirculation of the air through the apparatus comprising a cabinet to be placed in the space having an air inlet at the bottom and an air outlet at the top, an ice container at a one side in the upper part 01' the cabinet provided with transverse air passages and having drip holes through the bottom, a series of separated trays disposed transversely beneath the drip holes, a dehydrator case for solid hygroscopic material disposed at the opposite side within the upper part of the cabinet, air stream circulating means within the cabinet to draw a stream of air through the inlet opening and discharge the air through the outlet opening, partition means directing the stream 01 air from the inlet opening transversely through the trays, partition structure dividing the air stream to cause flow of a part of the air through the dehydrator case in contact with the hygroscopic 5 material and the remaining portion oi the air through the air passages of the ice container in heat exchange relation with the ice in the container to then be discharged through the outlet opening, a waste water tank disposed to catch 0 dripping ice water passing from the trays interposed in the path of the air stream adjacent to the inlet opening, said ice container and the passages thereof having air contacting heat. exchange walls provided with insulation, and 45 dampers settable to control the flow of air through the dehydrator case.

HIRAM J. KAUFMAN.

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