US1796410A - Refrigerating system - Google Patents

Description

March 17, 1931- R. E. SCHURTZ REFRIGERATING SYSTEM Filed Dec. 2 Sheets-Sheet l March 17, 1931. R SCHURTZ REFRIGERATING SYSTEM 2 Sheets-Sheet 2 Filed Dec. 20, 1918 5140\2444106 12. E Sc/zurfz Patented Mar. 17, 1931 UNITED STATES- PATENT OFFICE REFBIGERATING SYSTEM Application filed December 20, 1918. Serial No. 267,614.

The invention has for-an object to'eifect improvements in refrigerating systems-of the still, condenser, absorber type, having for its primary purpose the attainment of a satisfactory apparatus for the complete system which will be fully automatic in its operation, so that it may be safely left without attention for a considerable period of time.

It is an important purpose to provide an apparatus which will operate continuously for the transfer of li uid such as aqua ammonia from the absor er to the still, and to convey weak liquor from the still to the absorber with regularity, so that there will be no intermission of its essential functions, and not only that, but to obviate excessive fluctu-' ations in the refrigerating action of the system. For the attainment of these ends, therefore, the invention involves improvements in structure combination and arrangement of elements whereby their proper coordination for the ends in'view is attained, as will appear more particularly from the description hereinafter, and'the drawings, wherein,

Figure 1 is a diagrammatic detail of a system constructed in accordance with my invention, with certain detailsof structure approximated sufliciently'to enable the construction of the apparatus by those versed in .the art. I

Fig. 2 is a detail of a transfer ap aratus associated with the still and absorber or conveying strong liquor from the latter to the formerr Fig. 3 is a detail of avalve element therein, Fig. 4 is a horizontal cross sectional view of the transfer elem Fi 2,

ig. 5 is a detail sectional view on the line 5-5 ofFig. 2. i Fig. 6 is a detail horizontal sectional view of the valve shown in Fig. 3, on the line 6-6 of Fig. 2. S 7 There is illustrated an apparatus operative'on' the principles well known in such systems,.including a still 10, a rectifier 11, a condenser 12 for gas distilled, a collector 13 for liquefied. or condensed gas, the expansion chamber or coils 14, and absorber 15, these being elements well known in such apparatus,

ent, on the line44 of heated by means of a burner 10, supplied by fuelfrom a pipe 16, forming the outlet from a valve casing 17 including a tubular portion 18 fitted in-- the heads of the still chamber and extending entirely across the still and projecting therefrom at each end. a short distance. At one end, adjacent and outwardly of the pipe 16, a concentric seat 19 is formed in the tube against which there is adapted to. seat a thermostatic valve bar 20, mounted slidably in the tube 18, its end opposite the seat 19 being engaged by an adjusting screw 21 fitted in the end of the tube. Outwardly of the seat19- a pipe 22 is connected with the casing, by which fuel is led thereto to be admitted through the seat 19. From the upper part of the still distilled vapor is carried through a rectifying coil 23 enclosed in a jacket 24 through which liquor returned from the absorber is passed, and from this rectifier a pipe 25 is extended to an anti-siphon trap 26, located above the normal liquorlevel of the collector 13. This trap comprises essentially a closed receptacle into the upper part of whichthe pipe 25 leads, a pipe 27 having an end portion proected through the bottom of the receptacle, extending from the condensing coil 12, and an anti-siphon loop 105 leading from the top of the colle ctorand terminating near the bottom of the trap 26. The pipe 27 communicates with the collector 13, at its lower part as will be readily understood. It is connected to the coil 12 at a point intermediate'ly of. the height of the coil, which in the present instance includes a plurality of helices arranged on a vertical axis. The coil at the lower termination'is provided with an upward extension 28, leading into the bottom of the collector 13, While the upper end of the coil is similarly connected to the collector. This results in a circulation of the liquefied ammonia throughfithe coil 12 from the collector 13 and rapid condensation,

as is well understood:

is carried bythq pipe 29 to the expansion-'- 001114, an expansion valve30 being provided From the collector13 thecondensed liquid at the point of entrance of the gas to the expansion coil. I form a coil 31 beneath the absorbing chamber, having its upper ter minal leading into the base of the absorber, while its lower end is connected by a vertical pipe 82 to the absorber intermediately of its height, and preferably a short distance below the normal liquor level in the absorber. The return pipe 33 from the expansion coil is con nected to the coil 31 near its lower part Movement of liquor The foregoing includes the apparatus and function of the invention in the complete movement of gas in the system for refrigeration, from its distillation to its absorption. Movement of liquor is attained by forming a connectionwith the still in the form of a pipe 40, leading through the heat exchanger 41 to the upper part of the absorber, from whence it discharges by-pipe 18 into a sealed receiving tank 42 forcooling weak liquor, this tank having communication with the upper part of the absorber through a pipe 1 43 the receiving end of which projects a dis tance above the bottom of the tank 42. In this way the pressure existing in,the absorber is always communicated to the tank 42, and to govern the flow of liquid into the tank, a special formation of valve shown at 44 is employed (see Fig. 1).

Control of absorber liquor replenishment The valve includes a lower casing section 45 having a drain outlet leading into the upper part of the tank 42 so that gas pressure in the tank 42 is freely admitted into this section. A conduit terminal 46 is provided in the casing section 45, forming a continuation of the pipe 18' which discharges thereinto, this terminal 46 having a port in its upper side centrally of the casing section 45, and upon the section 45 a. cap 47 is provided, a diaphragm 48 being secured between the section 48 and the cap. A valve 49 is provided upon the diaphragm movable to engage over the port of the conduit terminal 46 for closure thereof under downward pressure of a spring mounted in a suitable cylindrical extension of the cap, and adjustable to vary its expansive force by means of a screw 50 engaged through the top of the cap. The spring is of suitable proportions to 'enable its adjustment to balance both the,

gas pressure of the absorber exerted against the diaphragm and the pressure in the conduit terminal 46 exerted against the valve 49.

Transfer from absorber to still Above the level of the still 10 and of the level of the rectifier 11 there is located a transfer device 55, by the action of which, Whenever the liquor in the absorber is above a predetermined level, regular transfer of liquor from the absorber to the still will occur,

without interrupting the operation of the still or of the absorber. This device comprises a cylindrical tank receptacle 56 as illustrated in the present instance, arranged on a vertical axis, having a head portion 57 and closed at the bottom by a plate 58 as illus. trated. The head 57 is formed with a central hollow neck 59 (see Figs. 2 and 3) of cylindrical form provided-with a port 59' at one side, around which a smoothly finished seat is formed upon which there is slidable a valve 60 adapted to close the port. The valve comprises a segmental plate carried loosely in a box 61 mounted upon a valve shaft 62 concentric with the receptacle.

The box 61 conforms to the shape of the valve 60, but is of a size to hold the plate loosely, as indicated, a spring 63 being interposed between the valve and box to hold the valve against its seat. In the neck 59 there is an intermediate horizontal partition 64, in which the upper end of the. shaft 62 is journalled, the lower end of the shaft being journalled in the bottom plate 58. The partition 64 and bottom plate 58 are formed with a plurality of small ports 65 and 66, and over these atthe outer sides there are valve disks 67 loosely splined upon the shaft 62. The valve disks are ported so as to simultaneously uncover the ports 6566 at one position, and to close them at another, under rotation of the shaft 62. The outer end of the neck 59 is closed by means of a top cap plate 69, while around the lower valve 67 there is formed a flange70 on the bottom plate 58, to which is secured a bottom cap late 71. The two cap plates lastmentioned are fitted to receive pipe connections for the conduction of li uid to and from the receptacle, and upon t eir inner sides are rovlded with springs 72 bearing against t e respective valve disks to hold them properly in seated positions. Connected to the neck 59 for the deliver of liquor to the port 59 there is a pipe 73, aving a siphon loop 74 t erein (see Fig. 1) with its bight portion disposed upwardly,'on or closely adjacent the predetermined or normal high level of liquor in the absorber, the receptacle 56 being disposed a suitable distance below that level, and one side of the loop bein led into the absorber near its bottom, a though it may be spaced a suitable distance from the bottom to avoid removal of weal: lig uor therefrom. The top cap plate 69 (see ig. 2) has a pipe 78 suitably connected thereto leading from the duct 25 and rectifier coil 23, while from the bottom cap plate a liquor duct 77 is extended to the jacket 24 of the rectifier 11, into which it discharges. From the rectifier jacket the liquor is carried by the pipe 77 through the exchanger 41 to the upper part of the still 10. From the upper part of the pipe loop 74 a gas pipe 79 is extended into the receivin tank 42 of the absorber, before mentione iao A small vertical loop 76 is formed in the pipe adjacent the transfer device 56. This will indicate the pressure in the still at all times.

:rection of the shaft '62.

Operating means of transfer device (see Figs. 2, 4 and 5) Within the tank 56, adjacent its lower part there is mounted a bellows 83 which may be spring expanded if the structure of the bellows does notserve the same function. It is connected by a pipe 84 to the upper part of the absorber. Connected with the movable element of the bellows to reciprocate therewith there is a horizontal rod 84' the support for which comprises arms 85 and 85 of a bracket secured to the inner side of the receptacle 56, an intermediate sto 86 being also formed on this bracket. T e outeror left hand end of the rod 84 is slidably mounted directly in the bracket arm 85, while at its inner part, adjacent the bellows, the rod= is engaged slidably in a slide or sleeve 87 which is itself slidable in "the arm 85'. The sleeve has flanges 87' and 88' at the right and left of the arm 85 and a heavy spring 88 is confined between the flange 88 and the bracket arm 85.

Upon the valve shaft 62 there is secured an arm 89, by which the shaft is rocked to operate the valves 67 and 63. This arm normall engages the side of the stop 86 opposite the ellows, the, valves being then closed. The arm is held against the stop by a light spring 90 confined between the arm 89 and the bracket arm 85.

The sleeve 87 is longitudinally slotted, and a key 91 is provided on the rod 84' slidable in the slot of the sleeve. Transversely arranged upon the inner end 92 of the sleeve there is pivoted an L-shaped trigger 93,

'which is a lever of the first order, the pivot being intermediately of its lower short arm, and this arm extends outwardly from the di- The trig er has a downwardly. extended bill 94 at -its ower extremity adapted to interpose in the path of and to be engaged by 9. lug 95 on the rod 84 at times to move the sleeve 87 to the right.

llhe upwardly extended arm 99 of the trigger is arranged to engage the lower side of a float 96 when the float approaches the lower limit of its movement. The float 1s fitted in the tank 56 as snugly as possible while permitting free movement, and theshaft 62 passes loosely therethrough. Upon the lower side of the float there 15 mounted a stirrup 97 close to the arm '89 and locatedto engage under a tongue 98 projected from "the trig- -commercial aqua-ammonia.

ing the absorber tank 15.

ger through the stirrup. The arm 89 on the shaft 62 has a lateral strike 100 thereon extended toward the trigger positioned to be engaged by a heel 101 at the junction of the upper and lower arms of the trigger when the sleeve 87 is moved from the right hand position shown in Figures 2 and 4. Under pivotal movement of the trigger when borne downwardly by the float, the heel 101 will pass below the level of the strike 100 of the valve shaft arm 89 and the bill 94 will soon after rise above the lug 95. i I

A diagonal pipe 73' is shown'extending from the upper part of the absorber into the loop 74, and preferably extends downwardly into a trap enlargement 74' formed midway of the'loop and extending downwardly therefrom, into which the pipe 84 also opens at the bottom. This functions in case high pressure should develop in the absorber tending to back liquor from the absorber into the tank 56. If such tendency should develop the gas from the upper partof the absorber would simply bubble into the trap when the level in the absorber is below the loop 74. The pipe 7 3' being submerged and requiring only to be quite small, when gas is released from the transfer device, it will follow the easier path through the pipe 7 9 rather than follow pipe 73.

Operation. of the system In use, the elements being assembled in the necessary relation, to initiate operation of the apparatus, it is suflicient to introduce into the still and into the absorber suitable bulks of The fuel conduits of the burner being connected to a proper fuel supply, the burner may be lit and distillation initiated. The vaporresulting; passes through the coil 23; passes thence through trap 26 and pipe 27 entering the condensing coil a little above its lowest part and reaching the collector 13. At this pbint it will have been reduced to liquid form after; sufficient pressure has been developed. After passing the expansion valve 80 or 125 and being evaporated in the coil 14 it will return through pipe 33 to the absorber coil 31, entering this a distance above its lower part andv by its buoyancy will move upward along the coil in small bubbles which are quickly absorbed either in the coil or soon after enter- This gas mpvement carries liquor through the coil br1ng-- ing fresh liquor constantly in contact with the entering gas and usually insur ng absorption principally in the coil. In time the liquor in -'the still will have been largely deplated of its ammoniacal content making 1t. suitable for transfer to the absorber. The return and absorption of gas from the expansion coilalso raises the pressure in the absorber. This finally acts on the diaphragm 48 of the valve 44 and permits pressure in;

the still to force liquor from the still through the pipe 40, the exchange element 41 and pipe 18 past the valve roper 49. The tank 42 then fills and over ows through the pipe 43 to the absorber tank 15.

Admission of fresh weak liquor to the absorber quickly lowers pressure therein and on the diaphragm 48, which permits the spring pressed valve 49 to close, cutting off further movement of liquor from the still for the time being. Should the temperature rise above a predetermined degree in the still, this will involve functioning of the thermostatic device 1720 to diminish the supply of heat. Accretion of strong liquor from the transfer device 55 will result in reverse operation of this thermostatic device to restore the still to full activity.

Meantime, the absorber having been filled above the loop 74, liquor will have already gravitated into the transfer device 55 through pipe 73 and port 59valve 60 being open and valves 67 closed. At this time the bellows are in open condition by pressure from the absorber through pipe 84 which is exerted at all times. The spring 88 holds the arm 89 to the left, compressing the spring 90. The

lug 95 is alittle to the left of the trigger, and the trigger will have been borne upon previously by the float so that its heel 101 bears against the arm 89 transmitting pressure of the spring 88. The bill 94 is above the level of the lug 95, which is at the left.

As soon as the entering liquor raises the float sufficiently, the stirrup 97 lifts the trigger, bringing the bill 94 below the lug 95 and then clearing the heel 101 from the strike 100 of the arm 89 and this clearance permits the arm 89 then to swing against stop 86 by pressure of weak spring 90 to close the valve 60 and open valves 67 at top and hottoin. Gas from the still at once enters at the top from pipes 25 and 78 and permits the liquor to drain rapidly through pipe 77 to rectifier jacket 24, after filling of which liquor may overflow therefrom through pipes 77' heat exchange 41 and pipe to the still.

It should be noted that the relative sizes are not correctly indicated in the drawing, certain parts. having been enlarged to enable clear representation.

The entry of still pressure to the tank 56 overbalances the absorber pressure in the bellows and the tendency of the bellows to remain open, and collapses them, moving the rod 84' to the right, the lug 95 engaging bill 94 and pressing the trigger and slide to the right compressing the heavy spring 88 against the arm 85. The trigger will then be in position so that when the float falls sufiiciently to again depress the trigger, the heel 101 may engage the strike 100 when the heavy spring is next released by lifting of bill 94. Immediately after this, the still pressure in the tank causes a somewhat violent escape of gas from tank 56 through 74 and 76 to the receiving tank 42 of the absorber, whereby an agitation of the cooled weak liquor therein is caused which results in almost instantaneous absorption of the gas entering. This obviates creation of excessive pressure in the absorber and resultant decrease of efficiency of refrigeration by raising the boiling point of ammona.

In the present instance the condenser, collector, and absorber, together with their immediately appurtenant parts, including the trap 26, are all disposed within a suitable large tank 106 into the bottom of which cold water is admitted through the connection 107, a drain connection for this cooling tank being provided at 108 at its upper part. The condensing coils under this arrangement get the advantages of the maximum cooling effect of the water while the remaining elements are affected sufiiciently to meet their need for cooling as will be readily understood.

By forming the float 96 of a size and shape to nearly divide the upper part of the chamber from its lower part, not only is the transfer mechanism operated, but it is made possible to utilize the gas direct from the still as one of the principal actuating agents, without the excessive loss of gas by absorption in the transfer device, owing to the fact that the float covers practically the whole of the surface of the liquid in the transfer device.

It may be noted that in my system it is possible to do without a heat control device of automatic form, if desired, permitting the burner or other heater to be set by hand, and the machine will then operate automatically otherwise.

The means responsive to action in the absorber and the still referred to in claim 3 hereinafter, is intended to designate the transfer apparatus including elements single or plural acting by increase or decrease of liquor weight, liquor level, or gas pressure, or two or more of these, to effect its operation.

I claim:

1. In a refrigeration system of the character described, a still, a condenser, an absorber, a liquefied gas collector, an evaporator and conduits connecting the above mentioned elements, in combination with means responsive to pressure in the absorber to- I gether with thermostatic means associated with the still, both constructed to govern the strength of the liquor in the absorber and the still so as to maintain with close approximation a uniform quantity of liquefled as in the liquefied gas collector.

2. n a refrigeration system of the character described, a still, a heater 'for the still, a condenser, an absorber, a liquefied gas collector, an evaporator and conduits connecting the above mentioned elements, in combination with means responsive to pressure 111 the absorber, thermostatic means associated with the still constructed to regulate the heat- 7 er and means constructed to respond to overflow in the absorber operatively associated-' with the still, the several of said means 00- operating to maintain a close approximation of a mean strength in and a meanquant'i ty of, the liquor in the absorber and in the still, to maintain With close approximation a determined quantity of liquefied gas in the liquefied gas collector.

3. In a refrigeration system of the character described, a still, a condenser, an absorber, a liquefied gas collector, an evaporator RALPH EDWARD SCHURTZ.

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