US2339813A - Absorption refrigerator - Google Patents

Description

Jan. 25, 1944. .1. N. Ro'rH 2,339,813

ABSORPTION REFRIGERATOR Filed Feb. 17, 1940 4 Sheets-Sheet 1.

' Jan. 25, 1944. J. N. ROTH 3 ABSORPTION REFRIGERATOR Filed Feb. 17, 1940 4 Sheets-Sheet 2' u. Iv

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Jan. 25, 1%. .5. N. ROTH I 2,339,813

' ABSORPTION REFRIGERATOR Filed Feb. 17, 1940 4 Sheets-Sheet s Jan. 25, 1944. R 2,3395'813 ABSORPTION REFRIGERATOR V Filed Feb. 17, 1940 4 Sheets-Sheet 4 JZZQQJ 54: 5? 4/ 1. ////l|m '1) g v f? V- (5' Patented Jan. 25, 1944 ABSORPTION REFRIGERATOR,

Joseph N. Roth, Belding,

mesne assignments, to

Company, Michigan Mich assignor, by Gibson Refrigerator Greenville, Micln, a corporation of Application February 17, 1940, Serial No. 319,541 9 Claims. (ol. 62-5) This invention relates to an absorption refrigerator, and more particularly to an improved ar-' rangement of the valves and associated parts in a two-pressure continuous absorption refrigeratorhaving a transfer chamber to efiect transfer of liquor from the low pressure to the high pressure portion of the system.

One feature of this invention'is the provision of improved valve means for connecting a transfer chamber alternately to the high pressure and the low pressure side of an absorption refrigeration system; anotherfeature of this invention is an arrangement whereby valves controlling both vapor and liquor flow to and from such a transfer chamber may be compactly assembled and arranged; still'another feature of this invention is the provision of'a simple valve andport arrangement enabling a single actuating device to achieve all of the desired arrangements; a further feature of this invention is the arrangement of the valve mechanism and all associated movable parts in such a way as to enable unit handling thereof; other features and advantages of this invention will be apparent fromsthe following specification and the drawings, in which:

Figure 1 is a schematic diagram of a continuous absorption refrigeration system embodying these inventions; Figure 2 is a detail eleva-' tion, partly in section, of thevalve assembly, the transfer chamber, and the bottom of the pressure chamber; Figure 3 is an elevation of the partsshown in Figure 2, transverse to such view;

Figure 4 is vertical sectional view of the valve lower assembly unit, showing the valve in its position; Figure 5 is a horizontal sectional view along the line 5-5 of Figure 4; Figure 6 is a vertical sectional view along the line 6-6 of Figure 4; Figure 7 is a vertical sectional view along the 'line 1-7 of Figure 4; Figure 8 is a vertical sectional view alongthe line 8-8 of Figure 4; Figure 9 is a vertical sectionalview along the line 99 of Figure 4, looking in the opposite direction from'Figure 8; and Figure 10 is 'a partial vertical sectional view of the topof the valve unit, showing the valve in its upper position.

The system in general comprises a'still adapted to have the mixture of a refrigerant and an absorbent, as ammonia and water, boiled therein by the application refrigerant vapor delivered thereby; an evapo rator or cooling unit in which the liq uefied re v an absorber in which the gas orvapor from the of heat; a condenser connect; ed by a vapor conduit to the still to liquefy the includes a transfer chamber intermediate the absorber and the still and a valve arrangement whereby the chamber is selectively connected to the absorber or to the still.

Referring now to the particular embodiment of this invention disclosed in the specific system diagrammatically illustrated in Figure 1, the still' in isadapted to contain a mixture of water and ammonia." A flue H is provided within the still and heat delivered thereto by the combustion of gas or some other fuel delivered to the burner l2. An analyzer tower I3, in the form of a long cylindrical tube enclosing the fiue ll, rises from the upper part of the still, which is a vertical cylindrical vessel. Both the analyzer tower'and' still areprovided with" bafiie plates, as M and I5, these plates serving to stratify the liquid in the still and to improve the efliciency of the apparatus. IT

Rich ammonia Vapors boiled 01f the liquor in the still pass upwardly through the analyzer tower I3 and then through the pipe connection Hi to the rectifier [1, a finned inclined tube at the top'of the system/ From there the ammonia vapors, any entrained water vapor having been removed by the rectifier, pass down through the connection l8 to a condenser l9 at the lower end of the apparatus. This condenser comprises one or more loops of piping, finned to increase the heat radiation. The'ammon'ia vapor is here con- 'densed into liquid ammonia, and then elevated by the vapor pressure behind it through the connection 20 to the receiver 2|.

The amount of ammonia boiled off and liquefied is'a functionof the concentration of the liquor in the still and of the amount of heat supplied to it, so'that if the concentration of liquor is kept relatively constant the rate of de-' livery of liquid ammoniaito the receiver 2| Will' be practically a direct function of the amount of ,heat supplied to the still. The amount of fuel'delivered to the burner l2, and thus the amount ofheat supplied and the rate of delivery of liquid ammonia to the receiver, can be regua a n any desired manner, as by a valve (not here; shown) actuated in conventional manner by a thermostat in the cooling chamber of the refrigerator.

.the dry evaporator 22, preferably comprising several -coilsbf piping, through the restriction .1

interposed by a valve 23 controlled by the float 24. The float and valve are so arranged that, as more liquid ammonia is delivered to the receiver, the valve opens further to permit increased flow to the evaporator to maintain the level of liquid in the receiver substantially constant.

Absorbing apparatus is provided in the form of an upper chamber or vessel 25 having extend ng downwardly therefrom a cooling and absorption loop. This loop is extending down from the bottom of the absorber vessel; the absorber cooling coil 21, finned for better heat radiation; and the upwardly extending pipe or leg 28, terminating in the vessel 25 slightly above the level of absorption liquidtherein.

Expanded ammonia vapor from the evaporator 22 first passes through a small loop or coil 29, to cool liquid in a chamber surrounding it, then through the pipe 30 into the rising leg 28. of the absorber loop, near the lower part thereof. The incoming vapor creates bubbles in the leg 28 of the absorber loop which provide a liquid lift or pump insuring circulation of absorption liquid through the loop. Inasmuch as the liquid in this rising leg is at all times the weakest liquor in the absorber, and cool as a result of passing through the coil 21, all absorption takes place in the pipe 28 under normal conditions, the liquid flowing out of the top of this pipe being quite rich.

The level of liquid in the absorber vessel 25 is maintained by a float 3| and valve 32 con trolling delivery of weak liquor from the still. The pipe 33 leads from the lower end of the still (where the liquor is weakest) through a heat exchanger 34 and then on up to open into the absorber, the flow into the absorber being controlled by the valve 32, which opens whenever the level of liquid in the vessel 25 drops below a desired point.

The means for returning rich liquor from the absorber to the still comprises as its principal parts a transfer chamber 35, a valve assembly 36, a pressure chamber 31 and associated operative interconnections. A flow connection is provided from the leg 28 of the absorber loop, through the jacket 38, pipe 39, and check valve 40, into the pressure chamber 31. When the valves are set in a certain position a flow path is provided from the pressure chamber, and thus from the absorber, through the pipe 4|, the valve mechanism, and the pipe 42 to the bottom of the transfer chamber 35, any vapor therein being vented through the pipe 43 and the pipe 44 (interconnected by the valve assembly) into the pressure chamber.

When the valve device is actuated, in accord-- ance with a condition of the system, to move the valves to another position, the pipe 43 15.60!!- nected to the pipe 45 which is open to high pressure vapor in the pipe l8; and the pipe'42 is,

connected to the pipe 46, connected through the heat exchanger 34, to a jacket 41 around a thermostat bulb in the still, and then through a pipe 48 into the analyzer tower. chamber and connecting pipes hi h pressure, the rich liquorthe analyzer tower and thence to. the still until now being at the valves are again moved to the position first described above.

formed by a pipe 26v therein flows into sure vapor through the pipes 43 and 44 to the chamber 31. The check valve 40, however, prevents these vapors from getting back into the low pressure side of the system; and the liquid in the chamber 31, cooled by the coil 29, rapidly absorbs the vapor, assisted in this respect by a fine stream of weak liquor bled into the chamber 31 through the conduit 49 branching from the weak liquor pipe 33. The rapid absorption of rich ammonia vapor causes the pressure in the chambers 35 and 31 to drop below the pressure in the absorber for a brief time, so that there is a positive pressure-driven flow of rich liquor from the absorber to completely refill the chambers and 31. When these are completely filled with liquid the Weak liquor entering through the branch pipe 49 immediately starts to raise the pressure therein, the check valve closing; and shortly the chambers 35 and 31 will again stand at high pressure. There is thus only a brief interval during which the valves in the assembly 36 must withstand the full difference of pressure between the high and low sides of the system.

The thermostat bulb 50, lying within the jacket 41, is a closed bulb having an actuating tube 5| opening into the lower part thereof. The bulb is adapted to be substantially filled, so that there is only a small vapor space above the surface of the liquid, by a liquid which also extends through the tube 5| up to the chamber 52 in the bottom of the valve assembly. A Sylphon 53 separates this thermostat liquid outside of it from refri erant within it exposed to the high pressure of the system, the interior of the Sylphon opening into a chamber in the upper part Of the valve unit being in the flow path from the transfer chamber to the still. When the pressure delivered by the actuating leg 5! exceeds the pressure within the Sylphon by an amount sufficient to overcome friction and the resistance interposed by snap acting mechanism within the valve assembly, the valves move to a position connecting the transfer chamber to the still. When the pressure in the bulb drops sufficiently below the pressure in the high side of the system, the valves snap back to a position connecting the transfer chamber to the pressure chamber, and thus to the absorber.

The liquid in the thermostat bulb is so chosen as to effect upward movement of the valve actuating rod 54 at a predetermined minimum concentration of liquor in the still. This thermostat liquid may, for example, be a mixture of refrigerator, for eight minutes i chamber is connected to the The transfer ammonia and water at a concentration slightly in excess of that at which it is desired to deliver more rich liquor to the still. The fact that the flow path of incoming rich liquor is around and past the thermostat bulb causes reverse movement of the valves shortly after connection of the transfer chamber to the still. Under normal operating conditions in a domestic example, a period of seven or may pass before the transfer still, and then its connection thereto may be broken within less than a minute. The time of the disconnecting is so arranged, with respect to the volume or the When the interconnection between the pres- V sure chamber andthe transfer chamber is again provided there is, of-course, a rush of high presconnected to the still; but

transfer chamber 35 and the rate of flow to the still, that at each transfer operation only about two-thirds of the liquor in the transfer chamber flows to the still; that is, the transfer chamber is designed to always have some liquor in the lower part thereof and vapor above it while it is the volume of, liquid in the chamber varies during operation of the system.

The earlier pending applications include my application Serial No. 296,995, filed September 28, 1939; a joint application of myself and one Ralph E. Schurtz, Serial No. 298,110, filed October 5, 1939; and my application Serial No. 314,704, filed January 19, 1940.

Turning now more particularly to the valve unit and associated parts of the system, and referring more particularly to Figures 2 to 10, it will be seen that the valve unit 36 has a housi e wmprising a number of interconnected castings providing the desired chambers, surfaces, and guide bearings. The actuating tube 5| leading from the thermostat bulb is welded to a small plate 60 adapted to be removably connected, as by bolts 6!, to a cup-shaped casting 62 providing the chamber 52 for the Sylphon 53. cup-like casting has bolted to the top thereof a plate 63, supporting the snap-acting mechanism and having a bore through the center thereof serving as a guide for the rod 54, and an inverted cup-shaped casting 64. This casting is provided with a transverse bore 65 therethrough in its upper part, made a closed chamber by the plate 66 bolted to one side thereof and the port plate 51 bolted to the other side. The port plate in tm'n has bolted thereto a connector plate 68. All of these connections are, of course, sealed by appropriate gaskets.

The connector plate, as may be best seen in Figures 2, 5 and 6, has the four pipes 45, 44, 4| and 42 welded at equally spaced points about its periphery; and the pipe 43 welded to its outer face. The connector plate has passages drilled therethrough from these five pipes, the passages being here identified as 44a, lla, 42a, 45a and 43a. These passages communicate with regis tering passages drilled through the port plate 61 and terminating on the inner face thereof, as may be best seen in Figure 9, in the ports 44b, 43b, 451), 4H) and 42b, each of these ports being connected through the passages to the pipe of similar number. All of the various pipes which are to be opened, closed and interconnected by the valve are those brought to a row of ports 7 more fully described, moving parts in the valve mechanism and associated actuating mechanism in a single unit, and makes it-readily removable as such a unit from the refrigerator. It can thus be tested as a unit before being placed in the system in production of refrigerators of this type; and it can be rereplaced as a unit in the field, so that repairs or rebuilding can be done in the factory. It will be readily apparent that at any time it is desired to remove the valve unit it is only necessary to unbolt' the connector plate 68 and the plate 60, heretofore described, and a similar plate 69 by which the .pipe chamber 65. A new similar valve unit can then merely be bolted in place and the system again immediately rendered operative. Any lost liquid or vapor can, of course, be replaced by rechargvarious pipes can thus all be permanently welded at their ends to castings or plates, without in any way destroying flexibility of assembly or field service. The only moving parts in the system subject to Wear, with the exception of the float valves, are thus all concentrated in one readily replaceable unit.

In order to have a gravity flow of liquid from the absorber through the pressure chamber to the transfer chamber, and then from the transfer chamber back to the still or generator Ill, it is necessary that the higher than the still I 0, and that the level of the transfer chamber 35 be intermediate. Previous refrigeration systems using a transfer chamber for transferring liquid from the low pressure side of as those of Ralph E. Schurtz, employed two One set was at the top action, therefore, the valves controlling liquid flow at the bottom of the chamber could not be also placed here, since in flowing from the transfer chamber to the still the liquid must rise above the level of its surface in the transfer cham- I therefore have the pipe 42 from the bottom of the transfer chamber 35 open into the in it completely uncovers the port 42b, which thus opens into the interior of the valve housing. The pipe 46 leading to the still l0 also opens into the interior of the valve housing, through its connection by the plate 69. When the port 42b is closed off from the interior of the chamber, the chamber or interior of the entire valve housing above the Sylphon 53 is kept filled with liquid at still pressure;

Turning now more member and its operating mechanism,

from the three different views in Figures' l', Sand 8, the valve member has in its face three oval cavities or depressions ll, 12 and '13. The longbe best "46 is connected to the' absorber chamber 25be' plate 67. As maybe seen seen in Figure 4, carried on ,a pair of plungers 14 and 15 .mounted for longitudinal movement in a block 16. Springs 11 and 18 urge these plungers to the right, speaking with respect to this figure, to place a desired positive pressure upon the valve member to keep it in the desired relation with the cooperating surface of the port plate.

The block 16 is mounted on the upper part of the rod 54, which thus transmits longitudinal movement of the bottom plate 19 of the Sylphon 53 to the valve member 10 to effect the desired flow control under changes in system conditions reflected by the thermostat liquid. The thermostat liquid, a particular concentration of ammonia and water, exerts an upward force on the plate 19 depending upon the temperature of the contents of the still iii; and still pressure in the high pressure side of the system exerts a downward force on this plate, since the pipe 46 is at all times open to the interior of the valve housing. In order to prevent the valve member floating in an intermediate position, snap-acting mechanism is provided. This is here shown as a pair of rollers 88 mounted on brackets 8| pivoted on the pin 82, the rollers being urged against a sleeve 83 on the rod 54 by springs 84. The sleeve 83 is provided with an annular bump or collar 85 cooperating with the rollers, so that the rod either stands in upper or lower position, and never takes any intermediate position.

It will thus be seen that when the concentration of liquor in the still is above a desired minimum the parts stand in the position shown in Figure 4. When the valve member is in the position shown in this figure, ports 42b and Mb and ports 43b and MD are connected; and port 457) is shut. Under these conditions the transfer chamber fills with liquid from the absorber, as has been described in connection with the general operation of the system. When the concentration of liquor in the still has reached too low a point, however, the pressure in the thermostat actuating leg is sufiicient to force the moving parts to their upper position, the position of the valve member in this case being shown in Figure 10. In this upper position port 42b opens to the interior of the valve housing; ports 45?) and 43b are connected; and ports 44b and Mb are closed. In this situation liquid, the transfer chamber throughthe interior of the valve housing and the pipe 48 to the still by the syphon action heretofore described, vapor to replace the liquid leaving the transfer chamber entering through the pipes 45 and 43.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended. claims.

I claim:

1. An absorption refrigeration system of ,the character described adapted to provide continuous refrigerating effect, including: a still; a condenser, the still and condenser being adapted to operate at high pressure; an evaporator; an absorber, the evaporator and absorber being adapted to operate at low pressure; a chamber adapted to be connected alternately to a high pressure portion and a low pressure portion of the apparatus, thelevel of the chamber being above that of the still; a valve unit near the top of the chamber. the unit having passing therethrough flows from the bottom of a flow path connected to the top of the chamber and another connected to the bottom thereof for withdrawing liquor from said chamber; this last mentioned flow path rising to the level of the top of the chamber before entering the valve unit; valve means in the unit so arranged that movement thereof effects variations in the flow paths; and actuating means, operative upon change in a condition in the system, for moving the valve means.

2. Apparatus of the character claimed in claim 1, wherein the valve unit has a single relatively small port member therein and the flow paths connected to the chamber terminate in ports in the member.

3. An absorption refrigeration system of the character described adapted to provide continuous refrigerating effect, including: a still; a condenser, the still and condenser being adapted to operate at high pressure; an evaporator; an absorber, the evaporator and absorber being adapted to operate at low pressure; a chamber adapted to be connected alternately to a high pressure portion and a low pressure portion of the apparatus, the level of the chamber being above that of the still; and a flow path between the bottom of the chamber and the still, the path rising above the highest level of liquid in the chamber and being arranged as a syphon.

4. Apparatus of the character claimed in claim 3, wherein that part of the path above the highest level of liquid in the chamber passes through a valve unit controlling said path of liquid flow and a path of vapor flow connected to the top of the chamber.

5. Apparatus of the character claimed in claim 1, wherein the valve unit includes therein all of the valves controlling movement of liquid from the chamber to the still, and all connections thereof to other portions of the system are readily removable.

6. A continuous absorption refrigeration system of the character described, including: a still; a condenser, the still and condenser being adapted to operate at high pressure; an evaporator; an absorber, the evaporator and absorber being adapted to operate at low pressure; a transfer chamber through which liquid in the absorber is returned to the still; a thermostat responsive to still temperature; a valve housing having a chamber therein; a port member having at least three ports therein; a valve element cooperating with the port member adapted to open-one of the ports to the housing chamber and complete a 1 new path through the other ports in one position,

and to cover the one port and block said flow path in another position; a connection from the still to the housing chamber; and pressure responsive actuating means for moving the valve element, this means having a portion exposed to and its actuation being a function of pressure in the housing chamber in relation to thermostat pressure.

7. An absorption refrigeration system of the character described adapted to provide continuous refrigerating efiect, including: a still; a condenser, the still and condenser being adapted to operate at high pressure; an evaporator; an absorber, the evaporator and absorber being adapted to operate at low pressure; a chamber adapted to be connected alternately to a high pressure portion and a low pressure portion of the apparatus, the level of the chamber being above that of the still; a valve unit near the top of .the chamber, the unit having passing therethrough a flow path connected to the top of the chamber and another connected to the bottom thereof, the valve unit having connected thereto a pipe leading to the still and. adapted to provide part of the flow path from the bottom of the chamber to the still; valve means in the unit so arranged that movement thereof efiects variations in the flow paths, the arrangement also being such that the valve means maintains the pipe filled with liquid when it is disconnected from the bottom of the chamber, whereby there is a syphon action when the connection is again completed; and actuating means, operative upon change in a condition in the system, for moving the valve means.

8. An absorption refrigeration system of the character described adapted to provide continuous refrigerating efiect, including: a still; a condenser, the still and condenser being adapted to operate at high pressure; an evaporator; an ab- 15 and a second flow path connected sorber, the evaporator and absorber being adapted to operate at low pressure; a chamber adapted to be connected alternately to a high pressure portion and a low pressure portion of the apparatus, the liquid level in the chamber being above that in the still; and a flow path between the bottom of the chamber and the still, the path rising somewhat from the bottom of the chamber before descending to the still, and being arranged 10 as a syphon.

9. Apparatus of the character claimed in claim 8, including a compact valve unit through which part of the path above the bottomof the chamber passes, this valve unit controlling said flow path to the upper part of the chamber, the first mentioned flow path being adapted to contain liquid and the second flow path being adapted to contain vapor.

JOSEPH N. ROTH.

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