US2003437A - Absorption refrigerating apparatus - Google Patents

Description

June 4, 1935. E. GRUBER A 2,003,437

ABSORPTION REFRIGERATING APPARATUS Filed Jan. 21, 1932 ATTO Patented June 4, 1935 i I UNITED STATES PATENT OFFICE ABSORPTION REFRIGERATING APPARATUS Edward Gruber, Cleveland, Ohio, assignmto Edmund E. Allyne, Shaker Heights, Ohio Application January 21, 1932, Serial No. 588,036

7 Claims. (Cl. 62-1205) The invention disclosed in this application reson of the fact that less drop in P r w r lates to refrigerating apparatus of the absorpthe still is nece ry to Dreduce appreciable retion type. turn of gas from the evaporator.

Where, in absorption refrigerating apparat s, The foregoing and other features of invention a still-absorber, condenser and evaporator are will be apparent fromthe following description, connected in operative cycle in the order mendrawing and s. tioned, and a drain is connected between the Referring to the drawing. i is a a liquor space of the evaporator and the still, there matie View Of a Ci including e v t is an undesirable tendency for, the useful reand Fig. 2 1S 8, detail view Of the connections bedrain back to the still rather than back through d liquid return p pe.

' the condenser, thereby shortening the refrigerat- In the drawing. i represents a t l-absorber ing cycle by diminishing th supply of u eful rein communication witha circulatory cooling loop frigerant. ,To overcome this defect in circuits of Comprising an p leg 2 and a w leg nthis type, a by-pass is provided around the c nected to a coil shown in elevation but normaldenser, suitably loaded or trapped toward the 1y a a d horizontally This D coil may evaporator so that the returning gas may find an be Cooled y y Suitab e means such as the fins easier course through the by-pass than through indicated at 5- During the heating p ri ere the drain on its way back to the still. In one ari n ir l n rou h h l p. ut it will be 2 rangement the by-passbalance leads from the set up dur n vap y th r turni as evaporator to a point in the circuit substantially whi h n s t 6 from th as and l quid pipe 1. at or slightly below the normal level of the liquor This pipe extends up above the still and to a in the still whereby, during the heating period, p int a t p of a liquid s al trap 8 closed this by-pass is sealed against the passage of gas eXeeDi fer the p p Which enter Extending 25 through it to the evaporator and the gas must flow upward from the boiler iS the p leg 9 Of a hairpin in the regular course through the condenser to entering t e bottom of a header l comthe evaporator, while during the refrigerating lnilnicating at its Other end With a down e llv cyc1e, the drain tube connection with the balance entering the trap a d eXtending o a po t near tube offers the counter action for pressure on top the bOttOmnnect d to the top or gas sp of liquid in the evaporator, holding the evaporator Of this p i a rec ifier pipe I? having tW liquid in equilibrium during refrigeration, the branches entering at the p ints 3 and I4 formed gas passes freely from the evaporator directly at the lewer edge M a ype rect fier and comback to the still without having to pass through prising an inner tub l and outer tube l6. and overcome the resistance of the other circuit These two tubes telescope wit espect to each frigerant to take the easier course through this tween the d a n and by-pass pipe and gas 10 through the condenser. other and are spaced very closely to form between 35 In another form of by-pass conduit is connected h m a v narrow n l r v y for th gas to the gasspace of the evaporator and leads back P s g throu h the rectifier. The lower and to the connection between the rectifier and conupper edges are both sealed except for the pipes denser with suitable trap means in the conduit which enter said cavity and either both Wa ls 40 to prevent the direct passage, of gas, during the. may b p d W a multiplicity Of fi 40 heating period, to the evaporator, but adapted to the outer one being as shown in the drawing. permit: the free'passage of the returning gas from. At the top, a rectifier condenser p p Connects the evaporator directly to the rectifier during the th t p f th fi r w h th t p of th nrefrigerating cycle, thus lay-passing the cond denser. This of course is much easier than a re-i The condenser is similar in structure to the 45 turn through the'drain because there is no seal at rectifier and includes an inner wall l9 and. outer the evaporator end of this by-pass pipe, as is the Wall 20, very closely spaced as before, to form an case with the drain. annular cavity between them in communication Such an arrangement is not only useful for with the pipe TheSe tWO telescoping p p overcoming one of the difllculties of a drain of'the are sealed together at their upper and lower 5 type mentioned, but is also effective in reducing edges and the chamber within the inner wall I9 is the time factor necessarily involved in cooling closed by suitable upper and lower caps 2| and the still at'the beginning of the refrigerating" 22 pec ve y cycle. In other words, refrigeration is started catin wit t annular cavity 56 earlier in apparatus arranged in this way by reatween the two tubes 19 and. 20 is a suitable bottom sump 23 connected to an evaporator pipe 24 leading up to and discharging into a downwardly inclined larger evaporator tube or pipe 25 connected to a dome 26 on the top of the evaporator 21. The evaporator is provided with a sump 28 into which is run the end of a drain pipe 29. The drain pipe extends upwardly through the evaporator 21 and outwardly through tube 25, and communicates with the enlarged upper portion II of pipe 30. The lower portion of pipe 30 is reduced in diameter as indicated by numeral 32. The reduced diameter portion 32 of the pipe 30 is joined to the gas return pipe 1 at a point 32' which is at approximately the normal level or slightly below the normal level of the liquid in the still at the beginning of the heating period.

Connected to the evaporator pipe 25 is a bypass or balancing pipe 33 which communicates with the gas and liquid return pipe 1 at the point indicated at 34, slightly below the point 32 where the drain enters the pipe I. The still ends of the .drain and by-pass pipes must be submerged at all times during the heating period, because the outgoing gas, during the heating period, must never pass through these pipes but must pass up through the trap 8, and through the rectifier into the condenser and there be liquefied. The liquefled ammonia in the condenser, of course, is dri en up to the evaporator from time to time.

If desirable, the upper cap 2| and the lower cap 22 may be provided with water pipes 35 and 36 respectively, which may communicate with the top and bottom of a water tank 31 for impounded or running water, to thereby cool the condenser by thermosyphonic circulation.

During the heating period the ammonia gas is driven from the absorbent in the still through the loop to the bottom of trap 8 where it bubbles up through the liquor and passes out from the top thereof to the rectifier and thence to the top of the condenser where it passes down and is condensed and liquefied, ultimately collected in liquefied form in the evaporator. In the meantime, however, no gas or liquor from the boiler is permitted to flow through the pipe 33 to the evaporator because the point 34 is always submerged during the heating period and a water seal is formed which will prevent such passage. When the heating period is over, a drop in temperature at the still lowers the pressure at this point, resulting in refrigeration at the evaporator and return of the expanded gas through the pipe 33 directly to the gas and liquid return pipe, from whence it must flow to the up leg 2 and into the still. The resistance to flow through the pipe 33 is far less than the resistance through the drain or through the condenser, rectifier, etc., hence the gas takes this easier course through the pipe 33. In going the other way it must overcome any column of liquid in the pipe 24 and the resistance of such a column is far greater than that through the pipe 33. This resistance through the by-pass is similarly less than that created by the seal at the evaporator end of the drain.

The enlarged portion 3| of the drain pipe produces a very important function, especially when used with smaller pipes leading to the evaporator and to the gas and liquid return pipe. The point 3|, which is the junction of the portion 3| and the portion 32 should be high enough to insure a complete rise in the smaller pipe 32 for the complete drain of the evaporator, and its level must be determined not only by the height of the drain riser in and from the evaporator, but also by the height of the column in the liquid seal trap I which of course determines the resistance to the flow of gas from the still. The enlarged central portion 3| provides for the collection of ample gaseous medium between the upper and lower seals in the drain pipe so that considerable movement of liquor in the still portion may take place without material compression of the gaseous medium and preventing any siphoning of liquor'from the evaporator to the still. In this way ample draining of the evaporator is assured.

As shown in Fig. 2, the drain pipe portion 32 is provided with an upturned end portion 32' which communicates with the pipe I at the point 32". The balancing or by-pass tube 32 on the other hand has a downwardly inclined portion 33' which enters the tube 1 at substantially the point 34. In this way the entering portions of the drain and the by-pass or balancing tube project their streams in opposite directions into the pipe 1 so that one does not influence the other.

What I claim is:

1. In absorption refrigerating apparatus, a still-absorber, condenser and evaporator connected in operative cycle in the order mentioned, a pressure drain conduit having a liquid seal connection with the evaporator and communicating with the still-absorber, said drain conduit being enlarged intermediate its ends, and a by-pass gas return connection leading from the gas space of the evaporator and provided with sealinz means effective to prevent flow toward the evaporator and arranged to permit free flow of returning gas from the evaporator toward the still around the condenser.

2. In absorption refrigerating apparatus, a still-absorber, condenser and evaporator connected in operative cycle in the order mentioned, a pressure drain conduit enlarged intermediate its ends having a liquid seal connection with the evaporator and communicating with the stillabsorber, and a by-pass gas return connection leading from the gas space of the evaporator to the still and communicating therewith at a point below the liquor level during the heating period.

3. In absorbtion refrigerating apparatus, a stillabsorber, condenser and evaporator connected in operative cycle in the order mentioned, a pressure drain pipe having an enlarged diameter intermediate its ends leading from the bottom of the evaporator and connected in the circuit towards the still, and a by-pass gas return connection leading from the gas space of the evaporator to the still and communicating therewith at a point below the still liquor level during the heating period.

4. In absorption refrigerating apparatus, a still-absorber, condenser and evaporator connected in operative cycle in the order mentioned, a liquid seal trap connected in the circuit adjacent the still, a cooling loop for the still, a gas and liquid return conduit leading from a point near the top of the liquid seal trap to the loop, a drain conduit connected to the bottom of the evaporator and communicating with the gas and liquid return conduit, and a by-pass for the gas during the refrigerating cycle, comprising a conduit connected with the gas space of the evaporator and communicating with the gas and liquid return conduit.

5. In absorption refrigerating apparatus, a still-absorber, condenser and evaporator connected in operative cycle in the order mentioned, a liquid seal trap connected in the circuit adjacent the still, a cooling loop for the still, agas and liquid return conduit leading from the liquid seal trap to the loop, a drain conduit connected to the bottom of the evaporator and leading to the gas and liquid return conduit, and a by-pass for the gas during the refrigerating cycle, com- 5 prising a conduit connected with the gas space of the evaporator and communicating with the gas and liquid return pipe.

6. Absorption refrigerating apparatus as in claim 5, wherein the bypass pipe is connected in the gas and liquid return pipe below the drain connection.

7. Absorption refrigerating apparatus as in claim 5, wherein the by-pa-ss pipe is connected in the gas and liquid return pipe below the drain pipe, and the drain and by-pass pipes lead into the gas and liquid return pipe in opposite directions.

EDWARD GRUBER.

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