US1050894A - Automatic refrigerating system. - Google Patents

Description

E. T. WILLIAMS &: H. T. BERNHARD.

AUTOMATIC REPRIGERATING SYSTEM.

APPLICATION FILED JAN. 4, 1910.

Patented Jan.21, 1913.

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AUTOMATIC REFRIGERATING SYSTEM.

' APPLICATION FILED :[AN. 4, 1910. 1,050,894 Patented Jan.21, 1913.

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EDWA B ID THOMPSON WILLIAMS, OF BROOKLYN, NEW YORK, AND HARRY THEODORE IBERNHARD, OF WEST HOBOKEN, NEW JERSEY.

AUTOMATIC nnrnrennarrue SYSTEM.

' Specification of Letters Patent.

Patented Jan. 21,1913.

' Application filed January 4, 1910. Serial No. 536,343.

To all whom it may concern:

Be it known that we, EDWARD T. WIL- LIAMS and Harlan T. BERNHARD, citizens of the United States, .and residents, respectively, of Brooklyn, in the county of Kings and State of New York, and of West Hoboken, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Automatic Refrigerating Systems, of which the following is a specification;

Our invention relates to refrigerating .systems of the type in which the refrigerat ing action is secured by the absorption of the sensible heat of'one substance, by, and its conversion into latent heat, of, another substance. This result is commonly eflected by expanding a liquid toa gas. The liquid we prefer to use is anhydrous ammonia but any other liquid which will boil 01f at a reduced pressure would'answer and though ing rooms may be controlled independently and with extreme nicety, and in 'which proper and safe operation at all times is assured.

Our invention difi'ers radically from. all

valve or valves on the suction side 'of the coil instead of by the control of inlet or expansion valves on the feed side of the coil.

In former systems the liquid was permitted to expand wholly or partially into gas on its admission to the cooling coils an the inlet valve governing this expansion w 5 automatically controlled and constituted thekey to the system. In our system on the contrary the liquid is permitted to flow into the cooling coils as needed filling the/same and of the compressor reducing the pressure to permit this. Our system is therefore known as a flooded or boiling off system, and it is this boiling off that we cont-rolfby automatically varying the passage at the suction end of the coil in correspondence with a thermostat. Boiling back is premore fully eXplainedi hereinafter.

Refrigerating-plants to meet practical requirements 'should'be able to maintain with exactness the temperature of each refrigerating chamber witlioutreferenceto the tempeature of any other such chamber, the vari- -vented by the use of check valves as will be a tion s in temperature between difierent chambers beingoften wide. One of the gravest defects of inlet expansion systems is I the necessity of a series arrangement of the coils with a thermostatic control on the last coil only, the cooling medium havingzsto pass successively through all the coils of which theremay be a large number. Efiorts to arrange the coils in multiple with individual inlet expansion valves have failed, for it is found that in expanding automatically from more than one point the gas is apt to short circuitthrough one or two of the coils, which would get too much refrigeration, while other coils in the systemwould be entirely without it. The clumsy expedient of manually controlled bv-passes obviously can not meet the difiiculty. I

In our system the cooling coils are preferably arranged in multiple and each? may be used separately from and independently of every other coil or may be temporarily out out entirely if desired' oreach coil there is an individual automatic thermo static control which may be set to maintain the desired pressure and therefore temperaturetherein and which assists; in controlling the operation of the motor. In additionto providing means whereby each coil may be completely cut off from the system, and in order to prevent the breakage of the coil's from the expansion of the incompressible liquid therein, we have made use of a by pass fromthe coil-to the suction line, there being in the by-pass an automatic pressure relief valve set to open when the pressure 1 great. Novelty is not claimed for the specific form of thermostatic control illustrated nor for thespecific: form of pressure relief valve. This may. be oi any well known typeand it is not necessary that the thermostatic control should be pneumatic although this is desirable since it secures positive action. On

the contrary the thermostatic control may' be electric, hydraulic or of other suitable character. We do however claim the individual thermostatic control in combination with other parts of the system.

In the practical working out of our system it has been necessary to devise means to prevent violent fluctuations in the am-' monia level whi'ch would destroythe usefulness of the system by abruptly varying pressure and temperature conditions therein.

These fluctuations are due largely to the tendency of the ammonia to boil back into the trap and over into the suction side of the line. We overcome this diihculty in four ways. First by providing an auxiliary tank connected by. restricted passages with the -trap and containing a float valve which controls the admission of ammonia to the trap.

The p urpose of this construction is to remove the float valve from the trap where it might be subjected to the severe and rapid fluctuation of. the level of the liquid and to locate it where the level of the liquid is substantially constant and where, therefore, it can'act to feed ammonia gradually as it is needed. The restricted connections between the trap and the auxiliary tank prevent changes of level in the trap from beingfelt immediately and severely in the auxiliary tank. We have also interposed check 'valves between the various cooling coils and the feed line and trap and haveinterposed another check valve between the feed line and the trap.

obvious that these check valves prevent the ammonia from boiling back into the "trap or into other coils. To relieve undue pressui'e, however, a bv-pass controlled by a relief valve is provided between the feed line and the trap so that when pressure-be-v tween the warm high pressure ammonia inthe feed line before it enters the trap and tank and therelative'ly fcool low "pressure ammonia from the coils.

creases the temperature of the.low-pressure ammoniafwhich is returned to the compressor and, by reducingthe temperature of the high pressure ammonia causes it to approximate the tempe'rature of the ammonia al.- ready in .the trap and thus prevent boiling It will be This I both inon its introduction into the tank. The

fourth means of preventing fluctuations consists ofdnsulat'ing the trap and float valve tank to prevent the absorption of heat from the surroundings, which might cause the liquid to boil. We also provide for the protection of the compressor against undue back pressure which sometimes occurs on starting the machine and while running warm. This protection is secured by the employment-of an automatic pressure valve in the suction line having a motor connected with the line on the suction side of the valve. Undue pressure on the suction side of this value will automatically cause it to close the suction line until the pressure has been reduced to normal. been used elsewhere and we do not lay claim to it save as it enters into combination with other parts of our system.

Another feature of our invention is the protection of the compressor and of the system from the danger of air leaking in,

which would be likely to happen should the pressure in thesuction end of the line become lower than atmospheric pressure. To prevent this result we provide a by-pass between the discharge end, of the line and the suction end of the line, this by-pass be- This idea has ing governed by an automatic pressurevalve, the position of which is controlled'by the pressure in the suctibn end of theline. When this pressure drops below atmospheric pressure or below the point determined upon, the valve opens the by-pass and thus connects the discharge side of the compressor with the suction side of the line so that a portion or the gas is pumped into the suction end of the line and back to the compressor until proper pressure conditions are restored, when the valve automatically closes the by-pass. We also employ a safety series switch in the circuit controlling the motor, operated automatically on an undue pressure rise in the discharge end of the line to stopthe motor until proper condi tions are restored and then to start it again. In multiple in the said circuit are the individual thermostatically controlled switches (correspondingeachto its particular coil. The employment of pressure controlled safety switches is old in vgrious pressure systems, such switches co stituting well Another; feature of the invention is the I arrangementlof the pump out line, tank and connections.

, Referring to the drawings: Figure 11 .a

view, maialydiagrarnmatic, of an embodi mentof our system. Fig. 2 is adetail view,

mainly in secth' n, showing'a valve for regw known protecting means. We provide also the thermostat and connections.

Our invention is most clearly shown in Fig. 1 which, as stated, is mainly diagram matic. While the details of the construction of the various valves, the' thermostatic controls and the pressure control are not in themselves of our invention but are Well known and may be purchased on the market, we have illustrated in Fig. 2 a valve and themeans-for automatically controlling the same.

In the system selected for illustration of our invention 1 designates the usual compressor; 2the condenser; 3 the receiver for refrigerant; '4 the cooling coils; .5 the trap 6 the feed line and the suction line. In systems of this generalcharacter-the cooling action, as. above stated, is secured by permitting ammonia or other'equivalent liquid to expand and thus take up heat, recompressing it, cooling and liquefying it and allow-- ing it to expand again in a regular cycle of operations. In' our flooded refrigerating system the feed line, coils and part of the suction line contain the liquid refrigerant the level of which should be closely maintained. In the system illustrated the elements above enumerated operate in the general way above mentioned. The compressor compresses the warm expanded gas and forces it into the condenser where it is cooled and liquefied and from whichit passes into the liquid receiver, from which again its which is below the level of the liquid in the receiver, to the trap 5 at the top of the system. From the said trap banotherportion of the feed line 6 which may be de-- scribed as, the supply line, it flows into the -various cooling coils which are arranged in l multiple across the .feed line 6 and the suction line 7, and thence it is returned through the suction line to the compressor.

'- .feed line and of maintaining an even level in'the trapjwill be first'considered. It will be noted first however that thecompressor 1 is of usual construction having the auxiliary trap 8 to prevent liquid from being carried 'over' into it and being protected from-nil where 'it is of a type to need such protection by any well known means. With 'it assothe trap and thus assist in maintaining the i desired level we provide the auxiliary tank llswhichmay he madeof say 4" extra heavy pipe capped at each end connected at thetop l and bottom of the tank to the trap 5 by assages con-' trolled by hand valves. In t is tank ll is pipes 12 having restricted arranged a float 13 controlling a valve l iin the feed line, the said valve governing he flow of liquid to the trap 5;

The arrangement described prevents any violent movement of the ammonia level in the large trap from communicating itself with suflicient violence to the small tank, to prevent the proper movement of the float valve. .This float and valve may be of any suitable knownconstruction adapted to withstand ammonia. In this connection We wish to state that although we have shown only one trap, auxiliary tank, float valve and connections, a plurality of sets of these elements would be employed should the heightof the system require it; as would be the case for instance, if the height were over forty feet, since the weight of the liquid in such a system would otherwise create a pressure in the lower coils which might interfere with the securing of a sufiiciently low temperature.

The trap 5, auxiliary tank 11 and the connections between them are provided with that there is no material expansion therein.

notwithstanding the fact that the trap is open to the suction line. The trap 5 is above the cooling coils and is connected below the level of the liquid to the, feed end of the coils and above the level of the liquidto-the suction end of the coils so that the liquid may flow by gravity into the coils.

From the bottom of the trap 5 leads theoutlet pipe 15 which is a part of the feed line. In this portion of the feed line leading from the trap to the coils are check valves 16 whicli'serve an important purpose in our system. One of these valves is located between the trap and all of the coils, and in The method of controlling the flow in the addition a checkvalve is located between each individual coil and the feed line.- The ture in one of the coils should suddenly he increased as by leaving open the door of the refrigerating compartment in. which the coil is located. It will be apparent that the idea of interposing a check valve between the coils and the high pressure line is applicable;

also where the coils are arranged in series, and that the statementin some of the claims that a coil is connected, or that coils are connected, to both the high pressure and the low pressure or to both the feed and suction lines does not exclude such series relation.

It is often desirable to have the temperature of one room greatly different from that of other rooms, the desired temperature depending of course upon the use to which the refrigerating chamber cooled by the coil is to be put. In order to secure this desirable 7 individual control we have arranged the coils inmultiple between the feed and suclines 6, 7 instead of in series, and have provided 'each coil on its suction side with a thermostatic control. As already stated, this thermostatic control may be .gf any desired and suitable character. To be suitable however it mustbe more than a mere means of cutting the coil into and out of the sys-v tem. Its function is toenable the work done in a coil to correspond with the temperature .dotted lines, is conveniently a diaphragm motor, the admission. of air to which tends to close the valve and the release of air from which tends to permit the valve to open in response to the action of springs not shown. When the temperature is too low the therinostat lets air into the motor and when the temperature is too high lets it out. It will be obvious that these valves are movable variable distances, the amount of their movement being determined by the thermo static controls which also effect it. This movement corresponds-roughly but not nee,-

essarily exactly to the change in temperature. As the temperature rises the valve opens and asit drops the valve closes being able to occupy closed position, open position or any intermediate position the tempera ture requirements at the moment necessitate. We also providea switch19 for each c011,

. the said switches being arranged in multiple as will be more fully'explained hereinafter. Each switchv is pressure controlled preferably by a diaphragm motor which it is not .thought necessary to illustrate. 20 is a small pipe supplying air under pressure.

This pipe, as stated, is'controlled in a .well

- known-manner by 'a thermostat 21 of known construction. These thermostats are located in the refrigerating chamber with the coil to,

which each corresponds and are set to main tain the temperature between eertain llmlts which; may be varied as desired.

The arrangement above described will be more fully understood on reference to Fig. 2

in which are illustrated in detailxone-of the valves 17 controlling the boiling off of ammonia from a coil 4:, the diaphragm motor 18 for operating the same and the thermostat 21 for"automatically varying the position of the valve by introducing air into the diaphragm motor or permitting it to escape therefrom.- -At the left of this figure is shownv the valve 17 having thejcasing b provided with the valve seat 0 with which cooperates the valve proper or valve plug 4 carried by the valve. stem -e, sliding in an extension .f of. the valve casing. This eXtension carries a support 9 to the top of which is secured the double diaphragm k by means of the top 70 of the motor. 'Beneath the double diaphragm is the plug 5 carried by the valve stem e and pressed upward by the springs m which act against a stationary part n supported by the part 9. The air pipe 20 enters the casing of the motor above the double diaphragm h by the, duct 0. It will be obvious that the admission of air through the duct owill force the diaphragm down against the pressure of the springs distances varying according to the amount of air so introduced, it being -,possible to. close the valve completely'or to move it to and retain it ,in intermediate positions. that when air is allowed to escape through the duct 0 the reverse operation takes place,

It' isobvious also it being possible to stop and hold the. valve at fully opened or closed position or at any intermediate position.

The means by which the admission to or outlet of air from the diaphragm'motor is controlled will now be described. pwis a .compressed'air reservoir communicating by another part of the pipe 2Q .with a duct 9 in the casing rfon which the thermostat is adjustably mounted. s is an air chamber in the casing 1- towhich the duct (1 leads and'from which leads the duct t which by the pipe 20 is in communication with the diaphragm motor. A valve a, spring pressed toward closed position, controls the admission'of air to the air chamber 8, this chamber being closed by an elastic diaphragm v carrying a block 20 in which is a v .duct w controlled .by a'valve 'w ,spring normally openwwhen permitted by the thermost-at to be so. A projection on the valve pressed toward open position. The valve u is normally closed and the valve to is u contacts with the head of the valve 10 The*-\ther'inostatic element is an expansible .disk A containing a volatile liquid Whose .pressure increases and decreases according block w is connected softhat it moves with 'to changes in temperature, causing the disk to increase and decrease in thickness.- The 7 ;com-pressible and,

' 'rise too much, would burst a coil if able type which when the pressure becomes lines .6,

Loudest the diskA either in the opposite sense, as above described, or in the same sense. The thermostatic .disk A is secured to the lever B adjustably-mounted "on the casing 1' as shown, the details of this construct-ion not needing any description. In the arrangement shown, a lever O pivoted at D on the adjustable lever E is connected at its upper end at F to the block w and at its lower end atG to the back of the thermostatic chamber. It will be evident at once that as the fluid in the air-tight thermostatic disk A expands with an increase of temperature the duct '11) will be opened permitting egress of air from the air chamber 8 and in consequence from the diaphragm mtor 18, permitting the valve d to move upward a distance'depending on the amount of air permitted to escape. When, on the contrary, the thermostatic disk A decreases in thickness as the temperature decreases, the valve Q02 is closed and egress from the chamber s is thus prevented and the valve u is opened, permitting compressed air to pass from the duct 9 to the air chamber 5 and thence to the diaphragm motor where it acts to move the valve d downward against the pressure of the spring an amount depending on the amount in chamber, the operation of the valves and the diaphragm i; being in each instance to reach a position in which the pressure in the chamber, if any, equalizes that exerted by the thermostatic disk. It will be apparent that the changes in temperature will cause changes in the pressure conditions in the diaphragm so that the position of the valve (Twill .correspond to temperature con ditions inthe chamber where the thermostat is located. If there were no direction chang- 1 ing mechanism such as the lever C between the thermostat and the block w, the valve plug d would be arranged. below instead of above the valve seat a. 1 This ofcourse is a meredetail of construction.

As stated the cooling coils 4 are arranged in multiple between the feed and suction 7, and each is providedat its feed end and at its suction end with ordinary globe valves 22 for isolating the coil. In this way each coil may be completely out out without interfering with the operation of any of the other coils. As ammonia is inif its temperature should the ends thereof were completely closed, we provide aby-pass 23'fr'om' each coil to the suction line. In each of these by -passes is located a pressure reliefvalve 24 of any usual and suitdangerously great will temporarily open the passage through the-by-pass to the necessary extent.

of air admitted to the motor. The air chambers thus acts as an equaliz- 7 Reference has already been made to the desirability of maintaining as nearly as pos sible an unvarying level in the system and 'means have already been described whereby we attain this result. Another feature of our system which aids in its accomplishment is the location of a heat exchanger for the warm high pressure refrigerant and the cool low pressure refrigerant. This exchanger 25 is located in that portion of the feed line 6 through which the liquid flows before reaching the trap 5. 4 passes very slowly through the exchanger and the result is that the temperature of this liquid is lowered so that it approximates the temperature of the liquid in the trap thus avoiding violent changes inlevel. This exchanger may be of any usual sort. We have shown it diagrammatically as a pipe of larger size to convey the high pressure refrigerant and surrounding the suction line through which the low pressure refrigerant flows. The precise part of the suction line on which the exchanger is located is' not material, although we have shown it as between the coils and the trap. Means are provided for cutting out the heat exchanger as follows: The by-pass 26 normally closed by the globe valve 22 and the globe valves 22 in the feed line adjacent the by-pass. Obviously the latter valves may be closed and the In a system of this character it is neces-' sary to protect the apparatus against an unduly high pressure at the suction side thereof, particularly when the machine is starting up or while running while the piping system is warm. To secure this protection we provide a pressure controlled valve 29 which may be of. any usual type suitable for use in an ammonia system. The dia' phragm 30 is indicated in dotted lines as is the valve stem 31. The diaphragm consti- 'tutes a motor which is connected by the pipe 32 with the suction side of the valve, the valve being set to respond to an unduly high pressure operates to close or restrict the passage through the suction line until the compressor has reduced the pressure in the suction" line sufficiently. to permit the valve to occupy its normal position again. I Another diificulty arises in connection with the operation of such a system in that the pressure The i nflowing liquid 1 in the suction line and in the compressor may drop below atmospheric pressure. This would quickly happen where all! but one or two of the coils in a large plant were shut down with the machine running at fullspeed. Therewould then be danger-of air getting into the system. To protect the compressor and the system against this we provide a by-pass 33 connecting the discharge side of the motor with the suction line 7. This by-pass is normally closedby a pressure controlled valve 34 operated by a motor the diaphragm of 'which 35 is shown in market in which the resistance in the circuit;

a: cuit'there is a break controlled by the double dotted lines.

This motor is connected with the suction line by a pipe 36 and is set to hold the by-pass normally closed but to open when the pressure drops below the predetermined point. When the by-pass is closed the compressor takes gas from the suction,

line 7 through the trap 8 and forces it out through the gas discharge pipe 10 into the system. When however pressure in the suction line 7 drops too low and the by-pass opens, a portion of the compressed gas is forced into the suction line, the gas being pumped around and around until proper pressure conditions. are restored when the by-pass will close automatically.

In connection with. the discharge side of' the motor we provide a pressure controlled safety switch37 of known type, which, as will shortly appear, indirectly controls the motor circuit so as to stop the compressor when the pressure" becomes unduly high and start it again when the low limit is reached.

This switch is arranged in series in the cir cuit of the motor controlling solenoid in 19 are arranged in which the switches multiple.

.In practice we prefer to make use of some one of the a proved starters now on 'the of the motor is gradually cut out in startmg. For the sake of. clearness however we have not shown the detailed internal wiring,

gbut have illustrated a simpler circuit arrangementwhich will now be described. '38

and- 39 are respectively the positive and neg-' ative leads ofthe main line whlch furnish current to the motor 40. In the motor cirpole switch 41 operated by the" solenoid 42,

which is bridged across the motor circuit,

and which includes in series the safety switch 37 and in multiple the switches 19,

w-the' portion of the circuit in which these switches are located being for conve ience designated by X, Y at the left hand si e and also at the'right hand side of the drawing.

The safety switch 37 is of the tumbler variety and is actuated by'an electro-mag net 43 bridged across the main circuit.- An

adjustable safety pressure regulator 44 of knownneonstruction such as is; already on the market, a Bourdon tube regulator for in-' stance, having a. pointer switch 45 controls the circuit. of electromagnet 43, being 'so arranged that as the pointer contacts on the high pressure side the current passes through the magnet coil 43, opening the switch37 and at the same time throwing the switch 46, located to be reversely operated to the switch 37, to its lower position, thus a breaking the circuit of the motor controlling solenoid.42 and in consequence the circuit of the motor 40 and stopping the, I compressor. In the operation described the switch 46'has, as stated, been moved to its low pressure position, and, when the pointer switch 45 makes contact with the low pres.- sure point, the circuit of the solenoid 42 is again made by the action of the tumbler switch 37 which at the same time moves the i In connection with this line is a reservoir 48 whichs'hould be'largeenoilgh to contain all the ammonia from one or two of thelargestcoils. The reservoir 1's connected by a pipe 49 wi,th the receiver,- and the pump-out line above the-reservoir. is

connected with the sisction side of the compressor by the pipe, .5 located as shown inthe various parts of the line and connections so as to enable any desired part of the 'system'to be drained independently of the rest. Theprocedure in Globe valves 22 are draining is to close-the globe valves 22 in the pipes 49 and 50 and in the connections to those parts of theisystemwhich it is not "desired to drain. When the liquid has been drained into the reservoir 48, the globe valve 22 immediately above it and the globe valve 22 between the trap 8 and the pipe, 50 may be closed, the globe valves 22 in' the pipe' 5O opened and. gas pumped out by the compressor; The liquid may be admitted from the reservoir to the receiver as desired.

Globe -'valves have been ment oned spe .cifically in a number of lnst'anoes already.

Various other globe valves are located in convenient positions, but the manner in which they are-used would seem to'be obvious and not to need special explanation.

\Ve have also shown usual gage tubes 51 on I v the traps v5 and 8 and on the ump' out reservoir 48. A pressure gage 52 s located 'on the discharge side of the compressor.

The importance of individu'al automatic thermostatic controls has been noted but their advantages may be made clearer'by the following explanation: The individual 'auwas;

tomatic thermostatic control for each coil may be set to open or close the valve on the ,by the thermostat as to partially open or close in correspondence with slight variations of temperature, and to completely open or close in correspondence with certain greater variations of temperature. It

has thus the additional feature of varying,

' due to the restriction or increasing of the orifice through the valve, of the boiling ofl' of the ammonia, and thus providing an additional temperature control. This thermostat control also assists in controlling the operation of the motor.

The operation of the system has already been explained so that a recapitulation thereof is unnecessary.

The advantages of the system have been pointed out and we need only add that it is the intention to which we lay claim rather than the particular embodinientillustrated herein.

What we claim is:

1. An automatic refrigerating apparatus comprising in combination a circulatory system, means for circulating a refrigerating mediuifn therein, a cooling coil forming'a part of said system, a valve on the suction side of said coil movable variable distances, and an automatic control for said valve effecting such variable movement.

2, A flooded refrigerating system comprising in combination a compressor, a condenser, a liquid receiver, a trap, a cooling coil, a feed line connecting said parts, a suction line to the compressor, and automaticmeans on the suction side of the coil to open and close the coil and to otherwise' vary the opening through it for regulatingthe boiling. oft otthe liquid therein.

3. A flooded refrlgerating system comprising in combination, a compressor, a condenser, a liquid receiver, a feed line connecting said parts, a cooling coil, a trap above the coil, connections between saidr'eeeiver and trap, connections between said trap and both ends of said-coil .to permit a gravityfeed of the liquid thereto, a suction line connecting the trap and compressor, and a thermostatlccontrol forsaidcoil on the suction side thereofvarying the size of the opening through the coil between open and close I as the temperature changes within the predetermined temperature range. V

4. A flooded refrigeratlng system com-' prising in combination a compressor, a con:

' denser, a liquid receiver, a trap, connection between the 'said parts, a cooling coil, said trap having an outlet and an inlet between prising which the level of the liquid normally stands,

nections" between the trap above the liquid and the compressor.

5. A flooded refrigerating system comprising in combination a compressor, a condenser, a liquid receiver, a trap, a cooling coil, a feed line connecting said parts, a suction line from the trap to the compressor, automatic means on the suction side of the coil for regulating the boiling oil of" the liquid therein, and a'check valve on the feed side of the coil to prevent refrigerating fluid from flowing back through the feed line.

6. A flooded refrigerating system comprising in combination a compressor, a condenser, a liquid receiver, a feed line connecting said parts, a cooling coil, a trap above the coil, connections between said receiver and trap, connections between said trap and both ends of said coil to permit a I suction line, automatic means to vary the flow through the coils, and a check valve on the feed line side of each coil.

8. A fiooded refrigerating system com- Incombmat -on, a compressor, a condenser, a liquid" receiver, a feed line with controlling the feed of liquid to the trap to maintain a li uid level in the system, cooling coils. in communication with the feed line beyond the trap, a checkvalve'in the said line between the trap and the coils, a

suction line in communication with the coils,

trap -\and compressor, and thermostatic -'wliichsaidparts are in connection, a trap 'in the said feed line, automatic means for coils connected in multiple across saidfeed and SllClllOIl l nes, and a valve in each c011 at therethrough'as the'temperature changes.

111A flooded refrigerating system comprising in combination, a compressor, a condenser, a liquid receiver, a trap, a" feed 11116 connected withfthe discharge side of the compressor and with said other parts, a'

' suction line connected with the suction side across saidfeed and suction lines, a valve of the compressor, a plurality of cooling coils below said trap connected in multiple in the suctionside of-each of said coils movablevariable distances, and an independent thermostatic control for each of said valves effecting such variable movement and determining its amount 12. A flooded refrigerating system comprising incombination, a compressor, a condenser, a liquid receiver, a trap; a feed line cpnnected with. the discharge side of the compressor and with said other parts, a suctioniline connectedwith the trap above the liquid and with the suction side of the compressor, a plurality of cooling fcoils ".40

below said trap connected therewith and disposed in multipleacross. said feed and suct'ion lines, a valve in the suction side of each 3 of said coils movable variable distances an (check valve in each coil on thereof.

' tip-1e across.- said feed and suction lines,

independent thermostatic control for each of said valves eife'cting such'variable, movementand determining its amount, and a the feed side 13. In an automaticflooded refrigerating system, a-cooling coil, means for isolating the same from the rest of the system, a normally closed bypass connecting the, cork with the suction side of the line, and a pressure relief valve in the by-pass to open the same on excess pressure.

"14. In a flooded refrigerating 'system in combination, a liquid receiver, a compressor,-

a condenser a feed line with which said parts are 111' connection, a suction line, a plurality of cooling coils connected in mulmeans to isolateindividualcoils, by-passes from individual coils to the suction line, and pressure relief valves in the by' -passes.

15. In a flooded refrigerating system'in combination with a compressor, a condenser. a liquid receiver, a cooling coil, trap and connections, an auxiliary tank in restricted communication with said trap, and a float valve in said auxiliary tank on the low pressure side of the system controlling the flow from the ammonia feed line.

16. A flooded refrigerating system comprising in combination, a compressor, a condenser, a liquid receiver; a feed line with :whichsaid parts are in communication, a

relatively large trap, a relatively small tank, restricted connections between said trap and tank, a float valve ih said tank for controlling the flow of liquid from the feed line to the trap, cooling-coils below the trap and connected with the trap below the level of the liquid, a check valve between-said trap and coils, a suction line connecting the suction end of the coils with the trap'and compressor, and thermostatic means to controll the passage of refrigerant through the 001 s.

17. In an automatic refrigerating system, a compressor, a condenser, a liquid receiver, a trap, a feed line with which said parts are in connection, aut bmatic means for controlling the feed of' liquid to the-trap, coolingcoils connected with the feed line beyond the trap, a suction line connected with the suction side of the refrigerating%o'ils,

with the trap and with the compressor, av

portion of said' feed line between the receiver and the trap being located. in ,pr'oxmity to a portion of thesuctioir line to eifect an exchange of temperature, and means to control the coils.

- 18. A: flooded refrigerating system comprisinga compressor, a condenser,-a liquid receiver, a trap,.a feed l ne having a portion trolling the flow ofrefrigerant to the trap, the said feed line having another portion to conduct. refrigerant from the trap, cooling coils below the trap, with said last named portion, a suctionline and in communication fordelivering liquid refrigerant to the trap, an automatic valvein said-portion for con-' incommunication with said cooling cQils,

trapand compressor, the portion of the feed line between-the condenser and the trap and some portion, of the suction line beyond the coils being located in proximity to effect an exchange of temperature between the warm high pressure refrigerant in the feed line and the cool low pressure refrigerant inthe suction line to assist in maintaining the level in the ammonia trap,- and automaticv means on the suction side of the coils to control the boiling off of the liquid refrigerant therein.

19. An automatic flooded refrigerating system comprising in combination, a liquid receiver, a com ressor, a cooling coil, a trap,

i 'compressor,

50 rality of cooling coils connected in '56- for driving rcontrollingr the electric motor having in "multiple a plurality of switches each-of pressure p v charge s de of theflme ad acent the comconnections between said receiver and trap,"

between said trap and the feed end of said coil and between the suction vend of said coil and said trap, connections between said 5 trap, and said compressor,

regulating valve between said trap and said compressor controlling't-he pressure said connection between them.';

20. An automatic refrigerating comprising in combination, a liquid receiver,

a compressor, a condenser, a feed line connecting said parts, a suction line to the com pressor, a pluralityof cooling" coils connected in multipleacross the feed and suction lines, independent thermostatic controls for individual coils for separately and continuously regulating the flow 'of refrigerant 2 therethrough as the temperature adjacent said coils changes, a motor for driving the a motor controlling circuit, and a switch governed by each thermostatic con- 'trol said switches being arranged in multiple in the motor controlling circuit.

21. In an automatic refrigerating system in combmation with a compressor, afeed line connected with the discharge side of. the compressor, a suction line connected with the suction side of the compressor, a

pluralityjof cooling coils connected in multiple; across .said feed and suction lines, a valve in the suction side ,of each of' said. coils to vary the passage of refrigerant sytherethrough by opening andclosing the coih and by otherwise varying the size of the opening through it, an electric motor for driving'the compressor, a circuit for controlling the electric motor having in mul- 40 tiple a plurality of switches each of which corresponds with one of the cooling coils, and

a thermostatic control corresponding to each' the suctlon side of each of said coilsmovable' variable distances .to control, the passage of refrigerant ther'ethrou'gh, an electric motor the compressor, a circuit for which corresponds with one of the cooling coils, a thermostatic, control corresponding so .to each coil effecting the variable movement of the valve andgcontr'olling the switch' corresponding to that, particular coil, a safety regulator connected to the dispress'or,

a condenser, connectlons between said compressor, condenserv and IGCBIVBI, and an automatic, pressure system';

' spons -a liquid receiver,

compressor-and coils, a valve on with a compressor, a feed trolling y the flow of a switchin series in-the motor controlling c1rcu1t, and meanswhereby the safety pressure regulator controls said series switch.

23. In an automatic refrigerating system,- a feed line, a suction line, a compressor, connections between both said lines and the compressor, a normally closed connection betweenthe discharge side of the compressor and the suction line, a valve in communica-r tion with the suction line automatically reive to the pressure inthe suction line and'set to open the connection betweenth'e discharge and suction sides of the compressor when the pressure in the suction line falls below a predetermined point.-

24:. An automatic refrigerating system comprising a compressor, a condenser, a liquid-receiver, a trap, cooling coils, and

"necessary connections therefor, a pump-out line having valve controlled connections -with the various coils and with the ammonia trap a pump-out tank below the coils and trap and forming a part of the pump-out line, a connection between the pump-out tank, and the receiver, and connections bebetween the pump out tank and the com-- presso 25.

a compressor, a condenser,

cooling coils, a

part-s, a suction means for preventing both undue increase and undue decrease of pressure in the suct1on line.

' 26-. An automatic refrigerating system comprising in combinatioma feed line, a suction 11ne, a compressor connected to both,

a plurality of cooling coils connected in multiple across said lines, a single automatic valve in the feed line between said v I the suction side of eachcoil regulating the opening through said coil, and trol' for each 1 '27; A refrigerating system comprising in combination, a feed line, a suction line, a

compressor connected to both, a, cooling c011 connected to said lines, a checl; valve in the feed line between said trolling the flow of refrigerant through said coil. 28, A floodedyrefrigerating system comprising in combination, a feed line, a suction line, a compressor and a liquid receiving trap incommunication with both said lines,

r In an automatic refrigerating system,

feed line connecting said. line'connecting the cooling coils with the compressor, and automatic of said last mentioned valves;

coil and compressor permitting free flow to said coil but preventing boiling back,

a thermostatic conand means for con- I a plurality of cooling coils connected to said 7 lines, a check valve in the feed line between said 00' and trap, and means for conthrough the coils.

refrigerating liquid v 29. A refrigerating system pornp rising in combination, a high pressure line, a .low'

end to the upper part of sand trap, acheckf wake in the connection between the trap and the feed end of the coil, a valve in the suc- 10 tion end ofthe coil, and a, thermostatic control for moving said 'i'alve variable distances 1n general correspondence with temperature changes affecting the thermostatic control.

Signed'b us at New Yorgh city,iN. Y. this,

30th day 0 December,"1909:-=-' a EDWARD THOMPSON WILLIAMS.

I Witness es:

JENNm DUPREE,

MABEL O. FAHNESTOGK.

HARRY THEODORE BERNHARQF

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