US1255723A - Refrigerating apparatus. - Google Patents

Description

M. F. EWEN.

mrmsmnue APPARATUS.

APPLICATION FILED JAN-4, 1915. 1,255,723, Patented Feb. 5,1918.

4 SHEETS-SHEET l.

M.'F EWEN. REFRIGERATING APPARATUS. APPLICATION FILED JAN- 4.1915.

Patented Feb. 5,1918.

M. F. EWEN. I

RE-FRIGERATING APPARATUS. APPLICATION FILED JAN- 4. I915 Patented Feb. 5, 1918 4 SHEETS-SHEET 3.

M. F. EWEN.

REFRIGERATING APPARATUS.-

APPLICATION man JAN- 4. 1915.

'Patentd Feb. 5,191&

4 SHEETS-SHEET 4.

4&1? Jivf/ W MALCOLM F. EWEN, OF CHICAGO, ILLINOIS, ASSIGNOR TO LARSEN ICE MACHINE COM- Pm (INC J, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

REFRIGERATING APPARATUS.

Specification of Letters Patent.

Patented Feb. 5, 1918.

To all whom it may concern:

Be it known that I, MALCOLM F. EWEN, a

citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Refrigerating Apparatus; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being vhad to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in refrigerating:apparatus and consists of the l matters hereinafter described and more par- 'ticularly pointed out in the appended claims. The invention relates to a refrigerating apparatus of the absorption type which includes in general a generator or still, an absorber, a liquid refrigerant receiver and an expansion chamber or coil, and in addition includes an expansion or conducting valve interposed between the liquid receiver and the expansion chamber for controlling the admission of liquid refriger- "ant thereto. a

.The improved apparatus is more particularly of the kind known as a continuously operating apparatus in which the generator or still and the absorber are always used respectively as a still and as an absorber and are continuously subjected, in the norml operation of the apparatus, the one to heat and the, other to the action of a cooling agent.

A pump is employed to withdraw the liquor saturated with the refrigerant from the'ab- S()l'l)0l and force it into the still, and the pressure generated in the still is made use of to force the desaturated weak liquor from the still to the absorber. I

No claim is made herein to a refrlgerating apparatus embodying the several features above referred to, but the invention lies in the combination of certain improved features with the other elements of such an apparatus whereby such an apparatus i! made commercially practicable and efiicient. These several features,-as well as the various advantages of the improved refrigerating apparatus, will appear more fully as I proceed with my specification.

In the drawings:

Figure 1 illustrates a view in front elevation of a refrigerating apparatus made in accordance with my invention, a part of said view being shown in section to more clearly lllustrate the interior construction thereof. I Fig. 2 illustrates a top plan View of the same.

Fig. 3 illustrates a view in end elevation of my improved refrigerating apparatus as vlewed from the right hand end of Fig. 1,

Fig. 4 illustrates a transverse vertical section through my improved refrigerating apparatus, the plane of the section being indicated by the line 4-4 of Fig. 1.

Fig. 5 illustrates a longitudinal vertical sectional view through the apparatus, the plane of the section being indicated by the line 55 ofFig. 2.

Fig. 6 illustrates a longitudinal vertical section on an enlarged scale through the'upper end of the absorber.

r Fig. 7 is a detail sectional view on an enlarged scale of a valve interposed in the connection between the condenser and the expanion coil of the apparatus.

Fig. 8 illustrates on an enlarged scale a refrigerant and such absorbent.

Referring now to that embodiment of my invention illustrated in the drawings and' particularly to Figs. 1 and 2:10 indicates the generator or still, 11 indicates the ab? sorber, 12' indicates the liquid refrigerant receiver, 13 indicates the pipe leading from the condenser to the expansion chamber or coil (13",) and 14 the return pipe leading from the said expansion chamber or coil back to the absorber and adapted to return the vaporizedexpanded refrigerant, ammonia, to the absorber, wherein it is taken up by the liquor, water. The admission of the refrigerant through the pipe 13 leading to the expansion coil or chamber is controlled by a valve mechanism 15 which is operated automatically and periodically in a manner later to be described.

Any convenient means may be used for heating the still or generator 10, and I have illustrated herein that most usually used and most conveniently at hand in the localities where refrigeration of the kind herein described is apt to be used, that is to say, a gas burner.. 16 indicates the burner which consists of a long p-ipe provided with suitable orifices for the escape of the gas and extending longitudinally below the still which as shown is in the form of an elongated drum. The still 10 is surrounded at the top sides and ends by means of a heat insulating jacket 17 which may be of any suitable or desirable construction. A stack 18 is connected with the jacket intermediate its ends for the escape of the products of combustion. The burner is supplied by a pipe 19 which is connected with any suitable source of gas supply. The burner is intended to burn all the time that the apparatus is in operation and therefore may be controlled by an suitable hand valve or cock (not shown The supply pipe, however,'is in addition provided with an automatic valve 20 for cutting off the supply of gas under certain circumstances to be more fully described later.

The absorber 11 and the condenser-receiver 12 are preferably made as illustrated in the form of upright elongated cylindric shells closed at top and bottom. Said shells are supported in any convenient way in an upright tank 21 adapted for containing cooling water. Said tank is preferably made of sheet metal and is supported as shown on end brackets or frames 22-22 which somewhat elevate the said tank above the floor upon which the apparatus is located. The still 10 is supported from the front wall of the tank 21 by means of suitable brackets 23-23.

The still 10 is connected to the condenserreceiver 12 by means of spaced pipes 24-2 4 which rise a short distance above the still and are then carried back through the front wall of the tank 21 and then upwardly to a point within the tank where they are joined together and to a common discharge p1pe 25 which enters the condenser-receiver tank 12 at the top! The pipes 2424 constitute a rectifier of familiar construction which is cooled by the water within the tank 21 so that the water carried from the still with the ammonia gas is condensed therein and directed back into the still.

The absorber 11 is connected with the still by means of a pipe 26 which is connected at one end, namely, the end 26, to the bottom of the absorber and at the other end, namely, the end 26", to the bottom of the still at one end. Said pipe preferably includes a branch 26 which is conducted horizontally above the still in the air jacket the flow being controlled by a valve 30. The

pump and the motor are slow acting and are arranged so as to withdraw periodically and continuously a small amount of saturated strong liquor from the absorber and force it into the still with each stroke of the pump.

The weak liquor is discharged in a familiar manner from the still into the absorber under the pressure within the still through a pipe 31 which has one end 31* connected to the bottom of the still at a point opposite and farthest removed from the end 26 of the strong liquor pipe 26, andhas its other end 31 openin into the topof the absorber 11. Said en 31 is preferably provided with a dischar e spray ring 32 by means of; which the wea liquor is discharged in the form of rain throughthe ammonia gas in the top of the absorber, so that it will rapidly and quickly absorb said gas. In the pipe 31 is preferably interposed a cooling coil 33 which extends upwardly through a space 34 in the front of the tank 21 which is divided from the rest of the tank by means of an upright partition wall 35. Said partition wall is closed at itsends against the end walls of the tank 21 and extends substantially to the top of said tank but is terminated a short distance from the bottom of the tank to form a communicating passageway 36 between the front compartment of thetank in which the said cooling coil 'islocated and the rear compartment of the tank in which are located the absorber and receiver. By this arrangement the water which is apt to be more highly heated on account of the temperature of the hot weak liquor, is prevented from coming into direct contact with the Condenser-receiver and absorber.

The flow of weak liquor to the absorber is controlled by an automatic valve 37. Said valve'as shown consists of a casing in the form of a T-joint 38; ofan apertured valve seat 39 fixed in one end of the cross of T- joint and of a vertically reciprocating valve needle or stem 40, which has guiding relation within a vertical passageway in a plug 41 fixed in the otherv end of the cross of the T. The valve is operated by a lever 42 having a fulcrum 43 located close to the valve stem 40 and mounted within a horizontal pipe 44 which'connects the T casing nata'zaa 38 with a T-joint 45 which is directly con- 'nected to the discharge end 31 of thepipe 31. The lower end of said pipe end 31 is closed by means of an apertured plug 46 which provides guiding engagement and supports a vertically reciprocating rod 47 that is operativelyconnected to the lever 42 by a pivotal joint 48. The rod 47 is provided at the bottom with a ball float 49.

The ball float 49 in connection with the lever 42 and valve mechanism 37 operates to control the admission of the weak liquor into the absorber in such manner as to maintain a pre-determined amount of liquid in to the bottom of the absorber where it has attached to it a discharge ring 14 by means ofwhich the ammonia gas in discharged at the bottom of the absorber so as to rise therein,

The cooling water for the apparatus is supplied by the exhaust of the water motor.

28 which drives the pump 27. As illustrated said exhaust is conducted by a pipe 50 up through branch pipes 51-51 to coils 52--52 rising vertically in the absorber and condenser-receiver respectively. The upper ends 53 53 of said'coils open through the tops of their respective shells and the overflow from said coils fills the tank 21. The

is connected in any tank itself is provided with an overflow pipe 54 which communicates with the front compartment 84 of said tank so-as to discharge from the tank the hotter water. Said pipe convenient manner with the sewer (not shown).

As it sometimes happens that the supply of water may be unexpectedly cut down 'or completely shut oii, I provide means whereby the apparatus may 'be stopped and the gas supply cut oil under such circumstances. This is particularly important since the continuous heating of the still without a supply of cooling water to dissipate and get rid of the heat might result in dangerous conditions. This means as shown is as follows:

55 indicates a float in the top of the tank 21 fixed to the end of a lever 56 which is fulcrumed at 57 to the top of the tank. Said lever has an arm 58 which carries a cam 59 p and a cam 60. The valves 20 and 30 are operated by spring controlled plungers 20 and 30 respectively, which are so arranged that they normally hold the valves open. The cams 59 and 60 are arranged to coact with said plungers in such manner that when the float 55, owing to the fall of the level of the water in the tank 21, descends to a certain point, said cams will act to close the fuel gas supply valve 20 and the water sup ply valve 30.

The upward movement of the lever 56 is limited by means of a pin61. 62 indicates a pivoted arm or trigger pivotally mounted on a rod 63 at the top of the tank and normally resting against the lever 56. The lever 56 has a notch 64 which is adapted to be engaged by the arm or trigger 62'when the leverin the descent of the float has reached a certain position, so that it will be locked in said position by said trigger; thus the valves 20 and 30 will both be locked and the further flow of fuel gas and water will be prevented until an attendant opens the valves.

Tn order that the water may fall to the predetermined required low level to operate the lever 56 as heretofore described after the water supply has failed, the overflow pipe 54 .for the tank 21 is provided with a supplemental by-pass 65, by means of which the water will flow into the pipe 54 and thus discharge the tank to the level required t operate the float. Said by-passage 65 is made of smaller diameter than the main overflow connection with the discharge pipe 54 so that under normal conditions it will have little or no efiect upon the discharge of water from the tank. As hereinbefore pointed out the admission of the liquid ammonia to the expansion chamber is controlled by the valve 15. Said valve is a positively operated intermittently opened and closed valve and difiers from the usual reducing or expansion valve in that'instead of providing for a continuous choked flow of the liquid ammonia through a restricted passageway to the expansion coil, it operates to admit at periodic regular intervals, at larger flow of liquid ammonia through an unrestricted passageway for a short interval. The liquid ammonia is thus supplied continuously but intermittently and the disadvantages resulting from the use of expansion valves are thus entirely done away with.

The valve 15 comprisesa casing 15 which is divided by means of a transverse wall 15 into an inlet chamber and an outlet chamber .71. The partition wall 15 is provided ,with a comparatively large aperture 7 2 and said aperture is adapted to be closed by a conical valve plug 73 on the end of a valve stem 74. The valve stem 74 is reciprocably mounted in a suitable stuifing box 75 which closes the outlet chamber of the valve casing. The inlet end of the valve casing is closed by a plug 76. The inlet valve chamber is connected to the condenser-receiver side of 1 the condensing pipe 13 and the outlet chamber to the expansion .coil side of said pipe. A coiled expansion spring 77 surrounds the valve stem 74 and bears at one'end against the stuffing box 75 and at its other end' against a washer 78 fixed on the upper end -of the valve stem. This spring thus normally tends to hold the .valve plug closed against the aperture 72.

79 indicates a lever pivoted at 80 to the valve casing and pivotally connected at 81 to the valve stem 74. The other end of said lever is attached to a plate 82 (see Figs. 1, 2 and 8), which depends into the path of a lug 83 on the cross head 84 of the pump 27.

The depending plate 82 and the lug are so shaped, the one with reference to the other,

that when the lug 83 in its movement with.

the coil spring 77 will cause the valve to.

close and thus shut off the communication between the inlet and outlet chambers of the valve casing 16. This spring is made very strong in its action so that the valve will be almost instantly closed after it opened. The result is that the valve is completely opened twice for each reciprocation of the pump but the 'open position is maintained for only a very short period. As the valve controlling the admission of liquid refrigerant to the expansion coil is positively opened and positively closed in the manner.

described, it will be manifest to those familiar with the art that the improved apparatus is entirely free from those difliculties which occur where a reducing or expansion valve is used and where the restricted openings necessarily used in connection with such valves are apt to be'clogged by scale or other extraneous particles which may collect or be present in the apparatus or where the movement of the valve itself in connection with the restricted opening may be interfered with and entirely prevented by the presence of such extraneous particles.

In order to positively cut off the admission of liquid refrigerant to the expansion coil when the back pressure rises above a certain point, when it would prevent the efficient expansion and vaporization of the ammonia, I provide the following mechanism in connection with 'the operating valve mechanism thus far described:

90 indicates a concavo-convex casing closed on one side by a thin sheet metal diaphragm 91 and connected on'its, other side opposite to the said diaphragm by means of a ipe 92 to the absorber 11 in such manner t at the pressure on the diaphragm will be equivalent to the pressure in the absorber. As long as the pressure in the absorber is such that the vaporized, expanded ammonia gas will be properly withdrawn from the expanslon chamber, the mechanism now to bedescribed will have no effect to influence the operation of the liquid ammonia admission valve 15. The heretofore referred to plate 82 which is operated upon by the lug 83 on the reciprocating cross head 84, is pivoted in such manner that it may be swung to one side so as to escape being struck by said lug. Said plate 82 is connected by a link 93 with the diaphragm 91. Under the ordinary pressure the diaphragm will have no effect onthe plate 82 but under a certain pressure which may be carefully pre-determined, thediaphragm will be forced to the left, as viewed in Fig. 8, so as to swing the plate 82 out of the path of the lug 83 with the result that the reciprocation of the cross head would have no effect upon the lever 79 connected with the valve 73 and thus said valve would remain closed under the action of the sprin 77. Thus the liquid refrigerant -woul be no longer supplied to the expani sion chamber and this condition of affairs would maintain until the pressure against the diaphragm 91 was reduced which could only occur after the pressure in the absorber sorber by the pump into the still and the.

weak liquor is forced by the pressure in the still from the still into the absorber.

' The operation of the float 49 and the valve 37 controlled by said float acts to maintain the proper pro-determined equilibrium be-' tween the amount of weak liquor in the absorber and the amount of liquor in the still under the varying conditions of operation of the pump due to variations of ressure of water that operates the motor to ive the pump.

The liquid ammonia'is admitted to the expansion chamber through a comparatively large unrestricted opening, at regular periodic intervals, so long as the conditions are such both in the apparatusitself and in the box or other chamber which is to be refrigerated, that no back pressure is accumulated in the absorber to prevent the required efficient refrigeration by the ammonia in the expansion chamber. As soon as the said back pressure for any reason rises beyond the proper predetermined point, the supply of liquid ammonia to the expansion chamthus made to depend upon the same controlling device is therefore correlated so that the part taken from the condenser-receiver is substantially replaced by an equal amount put into the receiver. The pump constitutes both a measuring device and a means for transferring the absorbent from the absorber to the still in certain timed relation with the operation of the valve connecting the still with the expansion chamber. Thus an excess of ammonia may be provided in the system without any evil effects in its operation, even though the system is as has been shown practically valveless.

As the exhaust water from the motor is conveyed to the cooling water tank in which is contained the absorber and thus constitutes the means for renewing the cooling water .and of maintaining the temperature thereof, it will be apparent that this renewal of the water is correlated to the amounts of absorbent intermittently taken from the absary temperature of the water will be therefore automatically maintained. Thus, when the motor is operating rapidly theamount of cooling water required to cool the absorber will be automatically increased and when the pump moves more slowly this sup ply will be automatically decreased and the proper amount of fresh cooling water is maintained without waste, being supplied just as and no faster than, it is required in the operation of the apparatus.

'While the apparatus contemplates the constant burning of the fuel burner and the constant supplying of the cooling water, at the same time the means hereinbefore described for the control of both the fuel gas supply and the cooling water supply act to cut off the fuel gas supply upon the failure of the water supply. The'failure of the gas supply of course would have no efi'ect except to stop the operation of the apparatus since the water would simply continue to be wasted to the sewer.

It will therefore be manifest that the apparatus is perfectly safe and may be operated without danger of any sort. In additionjit will be noted that, except forthe positively acting valves referred to, the ap-.

paratus is valveless and is therefore immune from the many disadvantages of automatic refrigerating apparatus of the absorption type as heretofore manufactured.

While in describing my invention I have. referred to certain details of mechanical,

construction and arrangement, it is understood that the invention is not in any way limited thereto, except as may be pointed out in the appended claims.

I claim as my invention:

1. In a refrigerating apparatus of the kind described, in combination with a still, an absorber, a condenser-receiver connected with said still, a conduit connecting said still to said absorber, a conduit connecting J said absorber with said still, a pump interposed in said second named conduit and means for operating the same, an expansion coil connected with said condenser-receiver on one side and said absorber on the other, a

positively operating valve'interposed doetween said condenser-receiver; and. saidrexpansion chamber, and means actuated "by said pump for opening said valve.

2. Ina refrigerating apparatus of the kind described, in combination with a still, an absorber, a. condenser-receiver connected with said still, a conduit connecting said still to said absorber, a conduit connecting said absorber with said still, a pump interposed in said second named conduit and means for operating the same, an expansion coil connected with said condenser-receiver on one side and said absorber on the. other, a positively operating valve interposed between said condenser-receiver and said expansion chamber, and means for periodically and automatically opening said valve.

3. In a refrigerating apparatus of the kind described, in combination with a still,

an absorber, a condenser-receiver connected for disconnecting said pump mechanism from said valve mechanism when said back pressure exceeds a predetermined amount.

4. In a' refrigerating apparatus of the kinddescribed, in combination with a still an absorber, a condenser-receiver connected with said still, a conduit connecting said still to said absorber, a conduit connecting said absorber with said still, a pump interposed in said second named conduit and sorber, a condenser-receiver, a cooling water tank in which said absorber and receiver are located, a pump for drawing strong liquor from said absorber to said still, a water motor for operating said pump, means conducting the exhaust water from said motor to said cooling water tank, said tank being provided with an overflow, a float in said tank, a main water supply pipe for said motor, a main fuel gas supply pipe for said still,

valves in said pipe for controlling the flowtherethrough, and means associated with said float adaped to automatically close said valves when the level in said cooling water tank falls below a certain point.

6. In a refrigerating apparatus of the kind described, in combination with a still, an absorber, a condenser-receiver, an expansion chamber and conduits connecting said several parts, a valve interposed between said condenser-receiver and said expansion chamber, a receptacle intermediate the absorber and the still for measuring predetermined amounts of absorbent to be transferred from the absorber to' the still, and

means for transferring the absorbent in said receptacle to said still at predetermined intervals in timed relation with the'operation of said valve.

- 7. In a refrigerating apparatus of the kind described, in combination with a still, an absorber, a condenser-receiver, an expansion chamber and conduits connecting said several parts, a valve interposed between said condenser-receiver and said expansion chamber, a receptacle intermediate the ab sorber and the still for measuring predetermined amounts of absorbent to be transferred from the absorber to the still, means for transferring the contents of said receptacle to the still, and means for operating said transfer means and said valve in predetermined timed relation.

8. In a refrigerating apparatus of the kind described, in combination with a still,

an absorber,,a condenser-receiver, an expansion chamber and conduits connecting said several parts, a valve interposed between said condenser-receiver and said expansion chamber, a measuring transferdevice intermediate the absorber and the still for measuring predetermined amounts of absorb- I cut to be transferred from the absorber to the still and for transferring themeasured contents to the still, and means for operating said measuring transfer device and sai valve in predetermined timed relation.

In testimony thatI claim the foregoing as my invention I aflix my signature in the presence of'two witnesses, this 31st day of December A. D. 1914:.

MALCOLM F. EWEN. Witnesses:

T. H. Amnns, GRACE M. FoRToN;

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