US1864661A

US1864661A - Refrigeration method and apparatus

Info

Publication number: US1864661A
Application number: US90827A
Authority: US
Inventors: Miller Ernest Baldwin
Original assignee: Silica Gel Corp
Current assignee: Silica Gel Corp
Priority date: 1926-02-26
Filing date: 1926-02-26
Publication date: 1932-06-28
Anticipated expiration: 1949-06-28

Description

June 28, 1932'. E: LL 1,864,661

REFRIGERATION METHOD AND APPARATUS Filed Feb. 2a, 1926 'r Sheets-Sheet 1 June 28, 1932. E. B. MILLER REFRIGERATION METHOD AND APPARATUS Filed Feb. 26, 1926 7 Sheets-Sheet 2 SN .000% n 5 21 G E-wi 5 June 28, 1932. E. B. MILLER 4,

REFRIGERATION METHOD AND APPARATUS Filed Feb. as, 1926 Sheets-Sheet Juile- 28, 1932. I E. B. MILLER REFRIGERATION METHOD AND APPARATUS Filed Fb'. 26, 1926 7 Sheets-Sheet 4 mw a attain;

June 23, 1932. E. B. MILLER REFRIGERATION METHOD AND AP PARATUS Fil ed Feb. 26, 1926 7 Sheets-Sheet 5 vweutoz June 28, 1932.

E. MILLER REFRIGERATION METHOD AND APPAR ATUS Filed Feb. 26, 1926 7 Sheets-Sheet .6

June 28, 1932. E. B. MlLLEF REFRIGERATION METHdD AND APPARATUS Filed Feb. 26, 1926 7 Sheets-Sheet 7 l vide an apparatus that requires no attend- Patented June 28, 1932 I UNITED STATES PATENT orrl'ca ERNEST mnnwrn MiLLER, or summons, MARYLAND, ASSIGNOR 'ro SILICA ear. eon-- ronerron, or BALTIMORE, MARYLAND, A conromrron or MARYLAND REFRIGERATION METHOD AND APPARATUS Application filed February 26, 1926. Serial No. 90,827.

The present invention relates to a method and apparatus for refrigeration, and more particularly to the type of refrigeration wherein a liquid is evaporated and the vapor adsorbed in asolid, porous adsorbent.

' The main object of the invention is to provide an improved, fully automatic apparatus ofv this type wherein there is no compressor, pump or similar machinery.

Another object of the invention is to proance, and is thoroughly dependable and foolproof so that it is suitable for the most eX- acting requirements, for example, refrigerating railroad cars. l p 7 The principal features of novelty are as follows: a p

1. An automatic control of the valve in the conduit connecting the evaporator and adsorber, so that the valve open when the porous material is adsorblng vapor, and is closed when the material is being activated and cooled.

2. Automatic means to keep the ice-making evaporator at a lower temperature than the evaporator used for cooling the refrigerating chamber. 4

3. The means and method "of ridding the the adsorbing material rapidly. This is obtained by condensing part of the vapor, liberated during activation, at sub-atmospheric pressure and the balance at a gher pressure. 5; Bidding the system of permanent gases byventing them from the second stage of the condenser, to the'atmosphere. y 6. Venting the permanent gases from the condensed vapors when the latter are hot.

Because the condensedvapor is hot, there is a minimum of air entrained therewith.

7. Controlling the return ,of the condensed vapor to the evaporator so that it varies inversely with the refrigerating effect being obtained; that is, the higher the temperature of the liquid in the evaporator of the refrigerating chamber, the more rapid the return of the condensed vapors to the evaporator.

8. Automatically controlling the activation of the adsorbing material. This activation may be governed by the refrigerating effect as indicated by'the temperature of the liquid in the evaporator; also by the amount of vapor condensed in the condenser and by g the temperature of the vapor liberated from the adsorbing material. The activation, after it is initiated, continues until the temperature of the liberated vapor falls, or in other words, until practically all .of the vapor is liberated from the adsorbing material.

9. Means connecting the two stages of the I .condenser so that vapor and condensate from the first stage are not discharged into the sec- 0nd stage until the pressure in the first sta slightly exceeds that in the second.

10. Means connecting the adsorber and the condenser, which cuts ofi communication between these two parts when the adsorber is adsorbing vapor but permits discharge of vapor to the condenser when the adsorbing material is being activated.

adsorbers, means for activating said adsorbersm rotation, the lntervals between successive activations depending upon the refrig erating effect; that is to say, the warmer the liquid in the evaporator, the more frequent the activations.

Other features ofnovelty will be apparent from the description 'taken in connection with the drawings, in which: i

Figure 1 is a diagrammatic illustration 0 11. In an apparatus having a plurality of an apparatus embodying "the present invention, and more particularly designed for the smaller sizes such ashousehold apparatus;

Figure 2 is a'diagrammatic illustration of an apparatus designed for larger units; a Figure 3 is a sectional elevation taken substantially on the line 33 of Figure 2;

Figure 4 is a somewhat diagrammatic illustrationof the gas distributor and the means.

for actuating the same from thevapor valves Figure 5 is a plan view-of the mechanism shown in Figure .4;

. Figure 6 is an elevation, mostly in section,

the device controlling V distributor taken substantially on the line 6-6 of Figure V Figure 10 is a sectional elevation taken substantially on the line 1010 of Figure 9;

Figure 11 is a sectional elevation of the valve controlling the return of condensed vapor to the evaporator;

Figure 12 is a sectional elevation of the valve controlling the flow of vapor from one of the evaporators;

Figure 13 is a partial diagrammatic view illustrating the modified means of controlling activation;

Figure 14 is an elevation, partly in section, showing the construction of an adsorber unit;

Figure 15 is a plan view of the tubular evaporator;

Figure 16 is an elevation showing an ar-.

rangement in which the valve controlling flow from the tubular evaporator isomitted; and

Figure 17 is a diagrammatic elevation of a modification.

Referring to Fig. 1 of the drawings, the form of apparatus there shown comprises an evaporator E adapted to contain an evaporable liquid such as brine, anadsorber A in communication therewith and charged with a solid, porous adsorbing material suchas silica gel, and a condenser C adapted to condense the vapor liberated from the adsorbing material and return it to the evaporator.

The evaporator may be of any suitable construction to present as large a surface as possible. In the form shown, it comprises a series of horizontal superposed manifolds 20, 21, 22 and 23. As shown in Fig. 15, each of these manifolds comprises a header 24 and a series of tubes or pipes, each of which is closed at one end and at the other end welded to the header. Each header has at one end an upwardly inclined portion 26 connected to a riser 27. The vapor evaporated from the liquid in the manifolds flows through the inclined portions 26 tothe riser 27. As explained hereinafter, liquid is supplied to the upper manifold and overflows through a tube 28 into the second manifold. Likewise, each of the manifolds is provided with an overflow tube 28 for supplying the next lower manifold. The upper ends of the tubes 28 project into the headers 24 so that liquid cannot overflow until it has accumulated .to such an extent as to reach the level determined by the upper endsof the tubes 28,

It will be noted thatthis evaporator presents a large external surface so that it is responsive to changes of temperature in the ing ice, then an additional evaporator 29 may be provided. As shown, this may be in the form of a tank having depressions 30 in its upper side to receive cans or forms containing the water to be frozen. Vapor from the liquid in the tank 29 passes out through the

pipes

31 and 32 leading to a riser 33. The tank 29 may be supplied with liquid from 'the lower manifold through an overflow pipe 34 similar to the overflow pipes 28.

The vapor from the evaporator is conducted to the adsorber. For this purpose the

risers

27 and 33 communicate with a conduit 35 leading to the adsorber. In order to make ice in the ice-making evaporator, the temperature of the brine therein should be 10- to 18 F., which is lower than the temperature of the brine in the upper evaporator. To obtain this result, at the beginning of an adsorption cycle communication between the upper evaporator and the adsorber is cutoff until the temperature of the brine in the lower evaporator has been reduced to some predetermined temperature (say 10 to 189 F Then the riser 27 is placed in communication with the adsorber and remains so until the end of the adsorption cycle. This may be accomplished by a valve 36 controlled by a thermostat having a temperature responsive element 37. As shown, this elementis disposed in the icemaking tank.

One form of the valve 36 is shown in detail in Fig. 12. It comprises a body 38 having an inlet 39 to which the riser 27 is connected, and an outlet 40 to which the conduit 35 is connected. Within the body is a valve seat 41 with which the valve member 42 co-operates rThe valve 42 is moved to and from the seat 41 to control the flow of vapor from the evaporator. For this purpose the valve 42 is carried by the end member or diaphragm ofa bellows-tube 43 of metal or other suitable material which, at the end opposite the valve, is secured to the valve body. As shown, thisis accomplished by securing the end of the bellows to a flange 44 on a tube 45 which projects through the removabl end wall 46 of thevalve body. This tube has a small bore and the end of the tube 47 extending to the temperature re-, sponsive element 37 is secured thereinas-by sweating or welding. The joint between the flange 44 and end wall 46 must be absolutely gas-tight and so the tube 45 is welded as at 48 to the end wall. To relieve strain on this turn is forced against the end wall 46. Thus by screwing up the nut 49,-the end wall 46 is clamped between the flange 44 and the sleeve 50.

The thermostat, comprising element 37,

tube 47, and bellows-tube 43, is filled with a suitable liquid that will expand the bellows when the temperature rises. Thus, when the temperature of the brine in the ice-making evaporator 29 is above the predetermined value, the valve 43 is held against its seat and no vapor is evaporated from the upper evaporator. The ice-making evaporator, on the other hand, is in direct communication with the conduit 35 by means of the riser 33, so that vapor is evaporated fromthe same, whereby the temperature of the brine therein is rapidly reduced. When this temperature has been lowered to the predetermined value, the valve 42 opens, thereby placing the upper evaporator in communication with the conduit 35. This valveremains open during the balance of the adsorption cycle.-

The conduit 35 leads to a valve housing 51, which in turn communicates with the header 52 of the adsorber. In the form of adsorber here show-n, the header 52-has a plurality of pipes 53 welded thereto, the lower ends of thepipes bein closed. A tubular screen 54 (Fig. 14) is Tastened in each pipe, extending throughout the length thereof, and projecting into the header. The annular spaces between the screens and inner surfaces of the pipes are filled with silica gel or other suitable adsorbent. Of course, as many of these adsorber units or manifolds will be used as are necessary to give the required refrigeration. For the smaller units, one section is sufiicient. This adsorber manifold is surrounded by a heat insulating casing 55, the upper end 56 being funnel-shaped and provided with a damper 57 which controls communication with the atmosphere.

Any suitable means may be used for activating the adsorbing material. In the form 1 of apparatus illustrated, a gas burner 58is "heating medium around and along the entire length of the tubes, when the adsorbing material is being activated, and also induces a a current of air upwards within the casing so as to cool the adsorbing material after activation and during the adsorption cycle.

A valve 60 within the casing. 51 controls the valve open.

evaporator. Normally this valve is open, but when the adsorbing materialv is bein activated, this valve is automatically close For this purpose the'lower end of the stem 61 of the valve rests on abello'ws-tube 62- of the type already described. The interior ofthis bellows is in communication, through tube 63, with'a temperature responsive element .64, disposed adjacentthe tubes of the ad sorber. Normally-the temperature of the ad sorber is relatively low and the bellows 62 is therefore contracted, the spring65 holding As soon as the heating means is turned on to activate the adsorbing material, the element 64 is afie'cted, expanding the bellows 62 and closing the valve 60, thereby cutting off communication between the evaporator and the adsorber! This valve will remain closed until the temperature in the adsorber drops sufficiently to permit 'contraction of the bellows 62, when it opens being aided by spring 65.

During activation of. the adsorbing material, the vapor liberated is discharged into the valve casing 61 which, below the valve 60, has communication with a condenser. .As shown, the vapor flows from the valve casing 51 through a short tube 66 into a chamber 67' in a housing 68. This housing is divided into two chambers by a horizontal partition 69. r The lower chamber is partially filled with aliq'uid, like mercury, and a tube projects from the partition 69 downwardly so that its lower end is submerged in the mercury. Above the surface of the mercury and below the partition 69', this chamber has communication, by means of a tube 71, with another small housing 72.

When the vapor liberated from the adsorber has its pressure slightly increased, it flows from the chamber 67 downwardly through the tube 70 and bubbles up through the mercury, then flows through tube 71 into thehousing 72. The housing 68 with the partition 69, tube 70 and the mercury thus constitutes a seal or check valve to prevent vapor passing directly to the condenser when the adsorber is adsorbing. The chamber 67 is of suflicient size to hold all the mercury,

so that if anything should occur to force the mercury through tube 70 into said chamber, it would not pass over into any other parts of the apparatus. The housing 72 contains a temperature responsive element 73 for a purpose presently to be described.

The condenser connected with the housing 72 is preferably in two parts so that part of the vapor is condensed under sub-atmospheric pressure and the balance at' atmosphericpressure. It will be understood that leak into the system, the rapidity with which the adsorbing material will adsorb the vapors is retarded. Even the slightest amount of permanent gases -will materially afi'ect the rate of adsorption.

The first stage of the condenser is shown at 74 and has one end connected to the housing 72 and the other end to a small condensate tank 75. This stage of the condenser is under vacuum. I

The second stage of the condenser is shown at 76. The vapor condensed collects in a tank or receptacle 77 having a vent 78 open to the atmosphere. The stage 7 6 of the condenser is therefore at atmospheric pressure.

The two stages of the condenser are connected so,that when the pressure of the vapdg being condensed in the first stage builds up to such an extent as to slightly exceed atmospheric pressure, it discharges into the second stage. For this purpose a check valve may be used to connect the two stages.- As shown,

' a mercury check valve is employed. It'commercury 7 9 prises a closed casing or tank 79 containing This tank is connected to the tank 75 through a vertical length of pipe or tube 80. The tube is of such length that the difierence of levels between the mercury in the'tank 79 and that in the tank 7 is about inches. The second stage condenser 76 communicates with the tank 79 throughthe tube 81." The lower end of the tube 80 is submerged in the mercury 7 9 The tank 79 is a little larger than necessary to contain all of the mercury, so that only a slight increase above atmospheric pressureisrequired to force fluid from the first stage to the second. The pressure in the second stage of the condenser being substantially atmospheric, a column of mercury of about 32 inches in height is maintained in the tube or pipe 80. When, during activation, the pressure in the first stage of the condenser builds up," this mercur is forced down the pipe 80 into the receptac e or tank 79 and finally when the pressure in the first stage exceeds that in the second, vapor and condensate will be discharged from the lower end of the tube '80 and bubble up through the mercury 7 9 and then flow through the pipe 81 into the second stage 7 6 of the condenser; The first stage of the condenser is designed to have a capacity to condense only a part of the vapor liberated, so that gradually the pressure of the vapor in this first stage will increase until it becomes sufficient to cause discharge into the second stage. i

If all the liberated vapor were condensed at atmospheric pressure, it would be necessary to heat theentire mass of adsorbent to the temperature corresponding to this pressure before any .vapor would be discharged into the condenser. With the two stage method, vaporbegins to be liberated and condensed, almost immediately follow'ng the ignition of the burner. By the time the premure in the.

first stage has increased to atmospheric, a conis returned to the evaporator through this .tube 82. A cooiing device 82 may be pro- "vided, if desired. The flow of the condensed Vapor back into the evaporator is controlled .sy a valve 83. One form of valve suitable for this purpose is shown in Fig. 11. It comprises a body 84 having an inlet to which the pipe 82 is connected and anoutlet 85 leading to the evaporator. The flow from the inlet to the outlet is controlled by'a valve 86 cooperating with a valve seat 87. This valve 86 is carried on the end wall of a bellows-tube 88 of the same construction as described in connection' with valve 36, and secured to the valve body in the same way. A temperature responsive element 89 inthe evaporator is connected'by a tube 90 with the bellows 88. When the temperature of thebrine in the evaporator rises, the bellows 88 is expanded, thereby opening valve 86 and permitting re turn ofcondensed vapor to the evaporator. "The evaporator being under vacuum and the tank 77 at atmospheric pressure, there is no diflieulty in effecting this return.

The starting and stopping of the activation of the adsorbing material is effected automatically. As shown, a gas or fuel supply pipe 91 is connected to a valve 92, the outlet of which is connected by means of pipe 93 .to the burner 58 under the adsorber unit. This valve is normally closed, but means is provided so that it is opened when theamount of condensate in the tank 77 is sufiiciently reduced. As the discharge of condensate from the tank 77 to the evaporator is controlled by valve 83 in turn responsive to the temperature of the brine, it will be seen that the fuel valve 92 is thus indirectly controlled by the temperature of the brine.

One form of valve 92 and the device for controlling the same is shown in detail in Figs. 6, 7 and 8. The valve proper comprises a valve body 94 divided into two compart-' ments 95 and 96 by means of a partition 97. The inlet pipe 91 communicates with the compartment 96 and the outlet pipe 93 with the compartment 95. The partition 97 has an opening 98 thereto, and this opening, in the form shown, is controlled by a ball valve, 99. Normally this valve is seated in the opening, thereby closing the same. Means is profuel to the burner under theadsorber w vided to-move it from its seat and thus supply I the amount of condensate in the tank 77 falls sufliciently. For this purpose, there is a float 100 in the tank which carries a stem 101 that Ill flange 106, and this flange supportsthe valve:

92. Thestem 101 at this point isv guided for vertical movement by a sleeve 107 carried by a flange 108 clamped between the flange and a flange 109. on the lower end of an upwardly extending tubular housing 110. The vent 78, previously mentioned, is provided in this flange 108. portion of the housing 110 is cut away as shown at 111 for the means connecting the valve and the float stem, which means actuates the valve. As shown, the stem 101 has a collar 112 set-screwed thereto, and this collar carries an adjustable screw 113 the projecting end of which is adapted to contact with a lever 114 rigidly secured to a short shaft 115 extending into the compart-' ment96 of the valve body. Within the valve body the shaft 115 has secured thereto a depending arm 116 which in turn near its free end engages the lever 117 near its pivot. The lever 117 in turn near its free end engages a bent lever 118 pivoted at 119. The free end of this bent lever 118engages the ball valve 99. Thus when the lever 114 iszdepressed, the amount of movement transmitted to valve 99 is greatly magnified. In other words, a very slight movement of lever 114 will. push valve 99mm its seat. The lever ll4is made in two parts pivoted together at 120 and held against breaking by spring 121'.

This-construction is provided so that if the motion of the float is so great as to force lever 118 against the partition 97, the lever 114 can' yield. The valve actuating parts are held in the position shown in Fig. 6 by. the spiral spring 122 on the shaft 115.

This structure provides a means for opening the valve suddenly instead of gradually. Means is also provided to hold the valve in this open position until substantially all of the vapor has been liberated from-the adsorbing material. It will be seen that liquid will gradually accumulate in the tank 77, while the adsorbing material is being activated, and this would cause the float to rise and close the valve before all of the vapor had been liberated from the adsorbing material. To prevent this, the housing 110 above the upper end of the float stem 101 supports a bellows-tube 123 of the type already described. This bellows is in communication with the temperature responsive element 73 through the tube124, these parts, like the other thermostats already described, being \filled with a suitable liquid so that changes in temperature in the temperature responsive element will cause expansions and contractions of the bellows 123. The lower end of the bellows carries a member 125 provided with a socket into which the upper end of float stem 101 projects. After the fuel valve has been turned on, and activation of the material started, the vapor liberated will come in contact with-temperature responsive element 73. This vapor being hot will expand the liquid in the element, thereby expanding bellows 123 and forcing member 125 down against the upper end of the float stem 101. Thus the float stem will be held in position to keep the fuel valve openuntil such time as the temperature of the vapor around the temperature responsive element 73-falls. This will not occur until substantially all of the vapor has been liberated from the adsorbing material. During this period of activation,of

cours'e liquid has been accumulating in the tank 77 tending to raise float 100 and thereby close valve 99. So, when the temperature responsive element- 71 permits contraction of the bellows 123, the float will rise, permitting cut off further supply of,

valve 99 to seat and fuel.

During this activation, the vapor liberated fills the adsorber, condenser and associated parts, thereby driving ahead of it any air or permanent gases, in the same manner that air is driven out of a steam-heating-radiator when the steam is turned on. Any air or permanent gases that have leaked into the system or accumulated in any way are thus vented through the opening 78 from the tank 77 As .the liquid in this tank is at an elevated tem-- perature, practically no air will be entrained therewith when it is discharged from the tank and returned to the evaporator.

After the apparatus has been built, to produce the vacuum therein and render the plant ready for operation, any suitable method may be employed. If desired, a vacuum pump may be connected to any suitable part of the apparatus to exhaust the air. Preferably, however, the adsorber is heated, thereby driving ofl vapor from the adsorbing material -and expelling air through the vent opening 78. Perhaps all of the air or permanent gases will not be eliminated from the system the first time, but enough will be discharged so that the refrigerating cycle will continue automatically. After one or two activations, all ofthe permanent gases will have been eliminated from the system, and thereafter the small amounts thatmay leak in or accumulate will be expelled during each activation. The operation briefly summarized as follows:

Vapor is eva orated fromthe evaporator and conducted y a pipe 35 to. the adsorber. Where the evaporator is provided with an of the apparatus may be ice-making part, the first part of this vapor comes from said ice-making compartment,

the valve 36 cutting-ofi the flow of vapor from the upper portion ofthe evaporator. After the brine in the ice-making compartment has its temperature sufliciently lowered, the valve 36 opens so that thereafter during the adsorption cycle, vapor is also taken from the upper evaporator.

During this time, condensed liquid in the tank 77 is being returned to the evaporator through the pipe 82, the valve 83 controlling the flow in accordance with the refrigerating effect, that is to say, the lower the temperature of the brine, the smaller the return flowof this liquid. Finally, when enough liquid has been discharged from tank 77, the float 96 falls sufliciently so that gas valve 92 is opened. Gas is thus supplied to the gas burner 58 under the adsorber unit and is ignited by the pilot light 126. Now the adsorber is heated and vapor is liberated from the adsorbing material and discharged into the condenser. The first portion of the vapor liberated from the adsorbing material is condensed under vacuum in the first stage 74 of the con-.

denser. Finally, the pressure in this first stage of the condenser builds up sufliciently so that it discharges into the second stage or atmospheric condensing stage of the condenser. Then the balance of the vapor is condensed at atmosphericpressure. All of the condensate collects in the tank 7 7. The hot vapor coming over from the adsorber strikes the thermostat element 7 3, thereby expanding bellows 123 into contact with the stem 101 of the float 100, thus holding the gas valve 99 open until substantially all of the vapor is driven oil from the adsorbing material.

Then the temperature of this vapor falls so that the bellows 123 contracts and valve 99 may close if sufiicient liquid has accumulated in the tank 77. After the supply of heating medium has been turned off in this manner,

' cool air enters at the bottom of the adsorber casing and flows upwardly around the tubes. thereby cooling the same. After a time the pressure in the adsorber falls sufiiciently so that the valve opens and another absorbing cycle is started.

As stated, preferably a brine is used as the refrigerant, but other liquids that can be evaporated under the conditions might be used. It is also preferred to use highly porous granular silica gel in the adsorber, but other adsorbent gels or materials might be used if they have sufiicient adsorbent capacity. As

a measure of the adsorptive capacity of an ad-.

sorbent suitable for this invention, it may be said that it should haveenough small pores so that it will adsorb at least 10% of its own weight of water when in equilibrium with water vapor at a temperature of 30 C. and

' a partial pressure of 22 mm. of mercury.

Although the invention has been described as employing gas for the heating medium, it is obvious that electricity, kerosene or other suitable heating mediums might be ,em, ployed. Of course, if electricity were used, the valve 92 would be replaced by an electrical valve, that is to say, -a switch.

Another method of controlling the fuel valve 92 is illustrated in Fig. 13." Inthis modification, the valve is controlled directly by the temperature of the brine in the eyaporator, instead of indirectly from this source through the float. The vapor condensed in the condenser collects in the tank -77 and is returned to the evaporator through the pipe 82 in the same manner as already described. For controlling the gas valve, there is provided a temperature responsive element 140 in the brine in the evaporator. This element is connected by means of a tube 141 with a bellows-tube 142. These elements are filled with a suitable liquid and constitute a thermostat. The lower end of the bellows-tube 142 is disposed to contact with the valve lever 114 of the same construction as described in connection with the first form of the invention. Whenthe temperature ofthe brine rises, the bellows 142 expands, thereby depressing the lever 114 and opening the gas valve. The lever is held depressed, and thus the valve open until substantially all of the vapor has been liberated from the absorbing material, by means of a second thermostat, consisting of the temperature responsive element 73, already described, and a tube 143 connecting this element to a 'oellowstube 144, adapted to contact with the lever 114. The hot vapor being liberated from the adsorbing material expands the liquid in the thermostat, by coming in contact with the temperature responsive element 7 3. The expansion of this liquid causes the bellows 144 to expand and hold the lever 114 depressed until such time as substantially all of the vapors have been liberated from the adsorbing, material.

In Fig. 16 is illustrated a form oftheapparatus in which the valve 36, previously described,- is eliminated. In this construction, the upper evaporator E is charged with a weaker brine than the ice-"making evaporator 29. Thebrine in the latter is of such concentration that it will freeze at about 10 to 15 F. When the apparatus starts on an adsorbing cycle, vapor is evaporated. from both containers 30. Finally, the brine in this icemaking tank also freezes so that evaporaof lowering the temperature of the brine in the ice-making tank sufficiently to freeze the'water in the containers, and this can be effected without the valve 36.

For the larger installations, it is desirable to have a plurality of adsorber units or manitical' spindle 165, aligned with the valve spinfolds. By providing several of these units,

each of a relatively small capacity, and activating the same frequently, the adsorbing material is utilizedto av maximum degree. Furthermore, the total weight of adsorbent for aplant of given capacity may be a. minimum.

An apparatus of this type is diagrammatically illustrated in Figs. 2, 3, 4, 5, 9 and 10 R,eferring to Fig. 2, the evaporator may beof the same construction as already described, and may or may not have the icemaking compartment, as desired. It is connected with the adsorber assembly by means of aconduit 150, which ends in a header. 151. In the form illustrated, there arethree adsorber units, A A and A each consisting of an adsorber manifold like that already described, and each disposed within a heat insulated casing. Each casing has a.

burner

152, 153 and 154 near the bottom thereof and a damper at the top to control the circulation of the heating medium and the cool air.

The vapor from theeva-porator. is thus conducted to the header 151. and passes through the

vapor valves

155, 156 and 157 to the adsorber sections A, A and A respectively. These individual valves 155,156 and 157 provide means so that the adsorber sections can be cut off from the evaporator when being activated. A vertical section through these ,valves is, shown in Fig. 4. The parts are shown with

valves

156 and 157 open and valve 155 closed, as the adsorber section A is being activated. Each of these valves may comprise an upper bellows-tube 158, a lower bellows-tube 159 and a spindle 160, connecting the two which carry the valve member 161 adapted to seat against the partition .162 and close the opening .therethrough. The lower bellows-tube 159, as illustrated in Fig. 3, is connected by means of a tube 163 to a temperature responsive element 163, disposed adjacent the tubes of the adsorber.- It will be understood that there is one of these temerature responsive elements for each of the ellows-tubes 159 so that the bellows 159 will be responsive to the temperature of its particular adsorber section. The diaphragm 164 of the upper bellows-tube 158 carries a verl dle 160. This spindle 165 projects above the top of the valve proper, for a purpose presently to be described.

When the vapor valve is closed and the adsorber section is being activated, vapor liberated from the adsorbing material will pass into the valve casing, then through conduit 166 (Fig. 3) into a chamber 67 of a casing 68 of the same construction as described in connectionwith the first form of the apparatus. It will be understood that there is one of these casings 68 for each of the vapor valves. The vapor then passes from chamber 67 downwardly through the tube 70, bubbles up throu h the mercury in which the lower end of this tube is submerged, and then passes through a short tube 167 into a header v169. This header discharges into the condenser which may be of the same construction as already described. Near the discharge end of this header 169 is a temperature responsive element 170, connected by a tube 171 to a bellows-tube 123,,the same as described in connection-with the first form 'of the apparatus, this bellows-tube acting to hold the fuel valve open as long as any vapor is being discharged from the adsorber section being activated.

Means is provided so that each ofthe adsorber sections will be activated in rotation,

and at intervals depending upon the temperature of the brine in the evaporator or the amount of vapor condensed. For accomplishing these ends, the gas valve 92 is connected by means of a pipe 172 to a distributor D. This distributor, as shown in Fig. 9,

has a chamber 173 into which the pipe 172 discharges, and which, through individual valves 174, may be placed in communication with

pipes

175, 176 and 177 leading respectively to the burners 154, 15.8 and'152. The valves 174 are opened in rotation and sue cessively by means of a cam 178 on a plate 179 non-rotatively mounted on a shaft 180. There is provided for each of the stems of the valve 174, a rocker 181 which engages the end of the stem and carries a roller 182 adapted to be acted 'on by the cam 178. Thus, as the shaft 180 is rotated, cam 178 will successively engage rollers 182 and thus open the valves 174 in rotation.

The movements of the

vapor valves

155, 156 and 157 are utilized to rotate the disc 179 at the proper times. For this purpose, the shaft 180 at one end has a gear 183 (Fig. 5) which meshes with a gear 184 mounted to rotate with a ratchet wheel 185. A shaft 186 is- The upper end of each of the valve stems 165 is adapted to engage one of the

arms

187, 188 and 189. In the position of the parts shown in Fig. 4, the left-hand valve stem 165 has engaged the arm 187, thereby rotating the shaft 186 and turning the pawl arm 190 in a counter-clockwise direction, as viewed in Fig. 10. This valve stem is associated with the valve 155 and adsorber section A which is being activated at this time. After the activation has been completed, the valve member 161 of the valve 155 will open, there by lowering valve stem 165 and permitting shaft 186 to turn in .a clockwise direction, as

viewed in Fig. 10. The spring 192 will effect this rotation and it will be communicated, by means of pawl 191 to theratchet wheel-185, which, through the gearing, will rotate the disc 179 and bring cam 178 under the next roller, thereby opening the next valve 174, so that the next time the main gas valve -92 is opened,.the adsorber section A will be activated. This will occur when the float falls sufiiciently to open the main gas valve 92. Then the burner 153 of the adsorber A will be ignited and temperature responsive element 163will thereby be heated, causing the valve 156 to close. This closing movement will raise stem 165 thereby through arm 188, rotating arm186 in. 'a counter-clockwise direction, as viewed in Fig. 10, so that when this valve 156 later closes, rotationof the shaft in the return direction will permit rotation of the cam disc 179, thereby opening the next gas distributor valve 174 and placing the parts in position so that the next timethe main gas valve 92 opens, the adsorber section A will be activated. It will be seen, therefore, that the adsorber sections are activated in succession andat intervals, depending upon the temperature of the brine in the eva orator.

ig. 17 shows a modified arrangement of the parts between the condenser and the evaporator, it being understood that the parts shown in this figure are adapted for use with the singleunit adsorber shown in Fig.1 or with the plurality of adsorber units shown in Fig. 2.

, The arrangement shown in Fig. 17 is designed to accomplish two purposes as follows:

1. To regulate the adsorption period for the upper evaporator and the lower, or icemaking, evaporator.

2. T o prevent air entering the evaporator from the float chamber in case the water leaks out of the latter.

The evaporator E may be of any suitable construction and is designed for refrigerating the chamber and the evaporator E for making ice'as previously described. Consequently the brine in the evaporator E must be kept at a lower temperature than that in the evaporator E.

columndecreases.

The vapor evaporated from the evaporator E passes through pipe 200 to the casing 201. Projecting from the bottom wall of this casing is an annularpartition 202. A .conduit 203 leading to the'adsorber projects through the said bottom wall and -'into the space enclosed by the annular artition 202. The ice making evaporator is in communication with the conduit 203 by means of a pipe 204. A cap 205 is disposed over the upper end of the conduit 203. The vertical wall of this cap is luted in mercury 206 in the annular space between the conduit 203 and the partition 202. As described hereinafter, the level of the mercury 206 rises and falls in accordance with the amount of water above the float in the associated part of the apparatus. The cap 205 is kept out of contact with the upper end of the conduit 203 by being carried on the float 207 disposed in the mercury 208 in the annular-space between the partition 202 and the outer wall of the casing 201.

This mercury 208 is the upper portion of the barometric column 209, so'that the level X of mercury rises and falls with changes in the atmospheric pressure. The annular space just inside of partition 202 is in communication with a chamber 210 by means of the tube 211. This chamber in turn is connected by means of tube 212 to a float chamber 213. The vapors-condensed in the condenser C flow into the casing 214 which at 215 has a vent to the atmosphere and which is connected by tube 216 with the float chamber 213. The mercury in the space within the partition 202, the tube 211 and chamber 210 is balanced by the water column in tube 212, float chamber 213 and tube 216 and the at- -mospheric pressure on the top of the water in the casing 214. Consequently the level of the mercury 206 varies with atmospheric pressure and the height of the column of water just mentioned. Inasmuch as the level X of mercury depends on the atmospheric pressure, and the level of mercury 206 de- 206 will fall until it is below the lower edge of the cap 205. This will place the evaporator-E in communication with the conduit 203, and this communication will not be interrupted until the height of the water column is increased the necessary amount.

From the foregoing it is apparent that the ice-making evaporator E is always in communication with the conduit'203, whereas evaporator E is. not in communication with said conduit until the height of the water So' when beginning an adsorbing cycle, vapor is first taken from the ice-making evaporator E, thereby rapidly lowering its temperature to the desired point. During this time the waiter level'in casing 214 and conduit 216 has fallen so that, at the desired point communication is established between evaporator E and conduit 203, because of the mercury level 206 falling below the cap 205. Thereafter vapor will be taken from the evaporator E as well as from the ice-making evaporator E.

The water condensed in the'condenser C flows into the casing 214, conduit 216, casing 213, tube 212 and chamber,210.- The float 217 controls the gas valve 92 in the manner described in connection with the other forms of the invention. The atmospheric pressure on the condensed water forces it from chamber 210 up tube 218 to the valve 83 described in the other forms of the invention, which controls the rate of the return ofthe water to the evaporator E.

. In the operation of these parts, at the close of a period of activation, the water level in casing 214 is relatively high because the vapor driven oif from the adsorbing material during activation has been condensed and collecte'd. Consequently, the cap 205 is luted in the mercury 206, and when the adsorbing period begins, communication between evaporator E and the adsorber is thereby cut off, but there iscomm'unication between the adsorberand the ice-making evaporator E. The brine in E therefore, is rapidly cooled to the desired temperature. The water level in casing 214 and tube 216 gradually falls because the water is being continually returned to the evaporator E. When ,thewater level has fallen to a desired point, say 219, the mercury level 206 has fallen a suflicient amount so as to be just below the bottom edge of the cap 205. Evaporator E is thereby placed in communication with the adsorber-conduit 203 and the brine in evaporator'E is then chilled to the desired temperature. The water level 219 continues to fall and finally reaches the level, say 220, when the float 217 begins to fall, and thereby opens gas valve 92 and starts an activating period. The starting of this activation. as described in connection with the other forms of the invention, causes the mainvapor valve adjacent the adsorber to close so that communication between the adsorber and the evaporators is cut off. Very shortly after this activating period has been started, condensed water will' flow into casperiod, vapor is always taken from the icemaking evaporator, but-from the refrigerating evaporator, only a portion, of the time.

In this manner the brine in the ice-making compartment is kept at a lower temperature than the brine in the refrigerating evaporator. I

This device also acts to prevent air entering the evaporator E if the water column falls to such an extent as to open the lower end of tube 218. As previously pointed out, the level of mercury 206 is maintained by the water column and atmospheric pressure on the top of the water column. Consequentl when the water column decreases in heig t the level of the mercury 206 falls and the mercury 206 in casing 210 thereby rises. The parts are proportioned sothat when the water column falls to thelevel 22-1. the mercury 206 will have risen to a'height above the lower end of tube 218, thereby sealin the same. This will prevent the forcing'o any more water or air throughthe tube 218 into evaporator E. Of course, if the water level falls to 22l or .thereabouts and the mercury level 219 in the casing 210 rises to a point above the lower end of tube 218, the'mercury will enter this tube and rise therein. During the next activating period the water level 221,

of course, will rise, thereby depressing the mercury in chamber 210 untifthe lower end of tube 218 is opened. At the moment this tube is opened, it may be that the first rush of water upthrough the same would tend to carry some mercury over to the valve 83. To prevent this, theexpansion chamber 222 is provided. This takes care of any mercury that might be carried over to said valve, and after the first rush of water, the mercury will fall back into the casing 210.

It will be noted that the valve 104111- the forms of the invention shown in Fi 1 and 2 has been omitted. This form of t e'apparatus, will act, satisfactorily without the valve 104, but if desired the valve may be provided, and in this case the device will act to secure the same objects.

In the normal operation of the apparatus, the water level will notordinarily fallto any such level as indicated at 221. However, if the refrigerating apparatus is shutdown by turning off the supply of gas, the water will gradually be returned to the evaporator so that the level will fall to the point indicated at 221. If the present device were not provided, air would then pass over to the evaporator and the apparatus would become all bound. With the device described herein, this condition cannot occur, and .even if the apparatus has been out of operation for a long period, it can be again set in operatlon 1 without any difliculties.

Where the float is provided with a valve like 104, this valve will prevent the water from falling to the level 221 unless the valve leaks. So where such val e 104 is provlded, the device justdescribed will prevent air passv 7 gkgver to the evaporator in case such valve e v I 1 Where the device shownin Fi 17 is assoevaporator is one or more always in communication wi adsorbers, so that there is continualevapora tion from this evaporator. The evaporator E for refrigerating the chamber, however, is periodically connected with the adsorbers so that evaporation from this evaporator is not continuous.

If desired, the valve 83 and the associated thermostat of all forms of the invention may be replaced by a manually controlled valve.

Preferably silica. gel is employed as the porous adsorbing material. In order to give a rule for determining an adsorbent suitable for the present invention, it may be stated that the material should have pores of such size that it will adsorb water vapor to such an extent as to contain not less than 10% of its own weight of water when in equilibrium with water vapor at C. and a partial pressure of substantially 22 mm. of mercury. A good silica gel under these conditions should adsorb from 21% to of its own weight of water. If desired, other gels, such as the gels, of tungstic oxide, stannic oxide,alumia num oxide and titanium oxide, might be used provided they are made so as to have the required finely porous structure.

Having thus described the invention, what is claimed as new and desired to be secured 35 by Letters Patent is: V

1. A method'of refrigeration consisting in evaporating a liquid, adsorbing the vapor in a porous material,in the absence of permanent' gases, activating the adsorbent to liberate the adsorbed vapor, condensing the liberated vapor, returning it to the liquid, and maintaining the system free of permanent gases by sweeping the gases out to the atmosphere during, and by, the activation of a the adsorbent. r

2. A method of refrigeration consisting in evaporating a liquid, adsorbing the vapor in a solid porous adsorbent in the absence of permanent gases, activating said adsorbent to drive off the adsorbed vapor and free the system .of any permanent'gases, condensing the vapor driven off from the adsorbent, separating the condensate and any permanent gases and returning the condensate to be evaporated again. r

3. A method of refrigeration consisting in evaporating a liquid, adsorbing the vapor in a solid porous material in the absence of permanent gases, activating the adsorbent to liberate the adsorbed vapor. condensing the liberated vapor and returning the condensate. to the liquid, a portion of said liberated vapor being condensed under vacuum and the remaining portion atv atmospheric pressure. I

4. The method according to claim 3 with the further step of separating any permanent I gases from the condensed vapor. ciated with a plurality of adsor rs such as 5 shown in Fig. 2, the ice-m 5. A method of refrigeration consisting evaporating a liquid, adsorbing the vapor in a solid porous material in the absence of perand returning it to the liquid, and controlling the activation jointly by the amount of con- 7 densa'te collected and the temperature of the liberated vapor.

6. A method of refrigeration consisting in evaporating a liquid, adsorbingthe vapor in a solid porous material in the absence of per- -manent gases, activating the material, a portion of the adsorbed vapor being liberated at sub-atmospheric pressure and the balance at atmosphericpressure, and using the ma-' terial to adsorb more of the vapor evaporated from the liquid.

7. Refrigerating apparatus of the character described including in combination, an evaporator, anadsorber communication with said evaporator and charged with a solid porous adsorbing material, means to activate said material, two condensers in series between said adsorber and evaporator, one adapted to condense under vacuum and the other at atmospheric pressure and means to return the condensate to the evaporator.

-8. Refrigerating apparatus according to claim 7 in which there is a vent to the atmosphere from the atmospheric condenser to permit the escape of permanent gases.

9. Refrigerating apparatus of the character described including in combination, an

evaporator, an adsorber in communication with said evaporator and charged with a solid porous adsorbing material, means to activate -adsorbing material, means to activate said material, means to condense at sub-atmospheric pressure a portion of the vapors liberated from the material during activation and to condense the balance at a higher pressure, and mean's to return the condensate to the evaporator.

12. Refrigerating apparatus of the character described including in combination, an evaporator, an adsorber charged with a solid porous vapor-adsorbing material, means controlling communication between said evaporatorand adsorber, means to activate said adsorber when said communication is .cut

off, means to condense the vapor liberated from the material and separate the condensate and. permanent gases, and means to return the condensate to said evaporator.

13. Refrigerating apparatus of the character described including in combination, an

evaporator, an adsorber charged with a sohd porous vapor-adsorbing material, means controlling communication between said evaporator and adsorber, means to activate said adsorber when said communication is cut 011:, a condenser connected to said adsorber to condense the vapors liberated from the material during activation, means to permit escape of permanent gases from the condensed vapors, and means, to cool the condensed vapor and return it to the evaporator.

- 14. Refri eratin apparatus of the character descri ed inc uding in combination an evaporator, an adsorber. in communication therewith charged with a solid porous adsorbing material, means to activate the material, twocondensers in series between the adsorber and evaporator one being in communication with the adsorber and adapted .to condense a portion of the liberated vapor at sub-atmospheric pressure and the other adapted to condense at a higher pressure, means.

connecting the two condensers constructed and arranged to permit the discharge from the first condenser to the second condenser when the pressure in the first slightly exceeds that in the second, and means to return the condensate to theevaporator.

15. Apparatus accordlng to claim 14 where in the means connecting the two condensers is a check .valve.

16. Apparatus according to claim 14 where- '49 in the means connecting the two condensers return.

V 18. Apparatus according to claim 17 wherein the valve is controlled by the temperature of the liquidin the evaporator.

19. Apparatus of the character described including in combination, an evaporator, an

adsorber in communication'therewith and charged with a solid porous adsorbing material, means to activate said material, vapor condensing means having a normally open vent to the atmosphere, 9. check valve between said condensing means and adsorber and means toreturn the then cool saidv material evaporator. a v

20. Apparatus of the character described including in combination, two evaporators, an adsorber in communication therewith charged with a solid porous adsorbing macondensed vapor to the' terial and means controlling the flow of vapor from one evaporator to the adsorber in ac- -cordance with the temperature of the liquid in the other evaporator.

21. Apparatus of the character described including in combination an evaporator, an adsorber in communication therewith and charged with a solid'porous adsorbing material, a. normally open valve between said evaporator and adsorber, means to activate the adsorbing material and heat actuated means to close said valve automatically during said activation.

22. Apparatus of the character'described including in combination an evaporator, an

adsorber charged with solid porous adsorbing material, a conduit connecting said evaporator and adsorber, a'normally open valve in said conduit, means to activate and rior to adsorbing, and means to close said va ve during said activation and cooling prior to adsorbing.

' 23. Apparatus'of the character described including in combination an evaporator, an

adsorber charged with solid porousadsorbing material, a conduit: connecting said evaporator and adsorber, a normally open valve in said conduit, ineans to activate said material, and means actuated by the activating means to close said valve during activation.

24. Apparatus of the character described including in combination, an evaporator, an adsorber charged with a solid porous adsorb- .ing material, a conduit connecting said evaporator and adsorber, a normally open valve in said conduit, means to heatthe material to activate it, and means to close said valve when the temperature of the material increases.

25. Apparatus of the character described, including in combination an evaporator, an adsorber char ed with a solid porous adsorbing material, a conduit connecting said evaporator and adsorber, a normall. open valve in said "conduit, means to heat t e material to activate it, and means to close said valve when the tem erature in the adsorber rises and holds sai valve closed until the temperature and-pressure an to amounts 4 suitable for adsorbingi 26. Apparatus of t e character described including in combination, an evaporator, an adsorber in communication therewith and charged with a solidporous adsorbin material, means to heat said material to 11 erate the adsorbed vapors, means to condense said vapors and return them tothe evaporator, and. means governed jointly by the condensate and the temperaturelof the liberated vapors for controllin said heating means.

27. Apparatus of t e character described including in combination, an evaporator, an

adsorber in communication therewith and charged with a solid porous adsorbing max teria means to activate said material started and stopped by the temperature of the liquid in the evaporator, and means to condense the vapors' liberated during activationand return them to the evaporator.

29. Apparatus ofthe character described including in combination, an evaporator, a-

therewith, each charged with a solid porous adsorbing material, said communication for each adsorber in rotation and means to activate the material in the adsorber thus cut out, said last mentioned means being actuated by the first mentioned means of t e previously activated adsorber.

plurality of adsorbers in communication means to cut oil combination, an evaporator, an adsorberjn' communication therewith and charged with a solidporous adsorbing material, means to activatesaid material, means to condense the vapors liberated during activation and having a vent to the atmosphere for freeing .the s stem of permanent gases, means to return the condensed vapor to the evaporator, and means to prevent air entering sa1d vent from passin to. the evaporator.

36. efrigerating apparatus including in combination,- an evaporator, an adsorber in communicatlon therewith and charged with a solid porous adsorbing material, means to activate said material, means to condense the vapors liberated during activation and having a vent to the atmosphere for freeing the system of permanent gases, means to return ,the condensed vapor to the evaporator, and

means to prevent air entering said vent from passing to theadsorber.

In testimony whereof I hereunto aflix my signature.

ERNEST BALDWIN MILLER.

30. Apparatus according to claim 29 in i which the means to'activate the adsorbers in rotation is controlled by the temperature of the liquid in the evaporator.

including in combination an evaporator, a plura'hty of adsorbers m communication therewith and each charged with a solid" porous adsorbing material, means to cone dense the vapors liberated from the adsorb ing material and return the same tofthe evaporator, and means to activate said ad:

31. Apparatus of the character sorbersin rotation "controlled by the amount of condensate.

32. Apparatus to claim which the activating means is also controlled v by-the tem rature of'the vapor liberated fromthea rbers. a 3 3. Apparatus according to claim' 29 in which theactlvating means is controlled by the temperature of the vapor liberated the material.

34'. ;Apparatus o f the character l includ ng in comb nation, an evaporator, 12 plurality of adsorbers each charged with a solid porous adsorbing material in communication therewith, a valve for each adsorber close said valves in rotation, and means to activate said adsorbers, including a distributor adapted to supply the adsorbers with activating medium in rotation, said distributor 7 being controlled by said valves.

' 35. Refrigerating apparatus including in controlling said communication, means to