US1676068A - Refrigerating apparatus - Google Patents

Description

July 3, 1928.

G. BAYER ERATING APPARATUS REFRIG Filed May' 12, 192e 2 Sheets-Sheet lNVENTOR ATORNEY July 3, 1928.

BAYER REFRIGERATING APPARATUS FiledMay l2, 192s 2 sheets-sheet 2' lNvEgToR ATToRNEY v Patented July i3, 192.8.

,UNITED fsfrarss- PATENT 0F.FICE

i Gnunnnz BAYER, oFtAUGsBUBG, Guam.

REFRIGERATING Arramrus.

- imputation. med nay 12,1925, serial N. 198,5o, and in VGermany my 22, 1925.

, This.v invention Vis an improvement in the apparatus shown in Patent 1,535,758, issued ,Apr-1l 28th, 1925 to Gebruder Bayer. In "said patent'there' is described and claimedan apparatus in which liquid which has v passed over to theevaporator from the stillabsorber during the heating period, maybe returnedto 'the still-absorber by the establislnnent' of an abnormal pressure difference,

and without the use of check valves, expansion valves, or other mo'vlng parts in the circult. In said patent this is accomplished -by connecting the evaporator and stillevaporator by conduitsI in which the` crosssectional areas of the ports are such in respect to each other that during the normal operation the pressure `dierences are such 1 that only vapor of the refrigerant flows to the still-absorber from the evaporator, but by raising the'pressure difference' liquid from the lowerpart of the evaporator may be caused to iiow to the still-absorber. The desired abnormal pressure difference for electing this fiow of liquid may be accomplished 4by an excessively rapid or low coolf ing ofthe still-absorber, or by a rapid or hgh'heating of the evaporator. 'Ihe patent proposes that the pressure increase be secured bythe pouring of boiling Water into a vessel containedin the evaporator. Thus, momentarily there is created an abnormally high pressure inthe evaporator which cannot be immediately relieved through the'gas outlet port, and which causes liquid to np' .the conduit from the bottom of the evaporator.

'lhe o bjcet of the present invention is to' provide means whereby the'return of liquid from the evaporator is accomplished in an extremely simple manner and automatically following eachheating period.

'lhe four figures ofv the accompanying drawings illustrate, somewhat diagrammatically, four forms of an' apparatus embodying the present invention.

The construction ustrated 1n Flg. 1 isA similar in many re pects to that shown in Fig. 4 of the patent above referred to. In this form there is provided a still-absorber a provided with a suitable heating devlce b and a cooling coil c. -A pipe d serves to` deliver the gaseous refrigerant from the still-absorber during the heating period to a condenser e in which-the is cooled and changedio liquid form. rl`he. liquilied refrigerant Hows from (hecondenser to au forming the lowest evaporator f, through a pipe which termihates in-a liquid seal IL. During the cooling .these ports p .and p3. The port p is so positioned that it is above the maximum liquid level in the evaporator', and the port pavisso positioned that it is slightly below this maximum level. The lower end part 0 of theA pipe i extends tothe bottom of the evaporator, where it opens intoy a 'sump part of the `evaporator chamber.

The conduits g and i are of the same relative cross-sectional areas as the corresponding pipes shown in said latenlt 1,535,758,- that is, the pipe i is materially larger than the -pipe g so that return of the liquid may be accomplished without the use of valves.

In Fig. l there is shown a cell n into. which .boiling water may be poured if.-de sired, for'the purpose of producing a sudden 'and higher pressure difference betwelthe water .pass over with the gas duringthe preceding heating' period.

"if there has been an abnormal amount of The ports or openings p', p2 and p3 are of considerably smaller area than is the single hole shown in F ig.4 of the patent above rcferred to. .As-a result of the proper selecence of pressure between the still-absorber and the evaporator, that is, upon a relatively slight cooling of the still-absorber or a relatively slight heating of the evaporator. the vapors which are produced in the evaporator cannot pass oli' by the very small uppermost `llo tion of'the port areas, even with a low differhole p or even through the holes pand p2' if the latter be uncovered. As a result, liquid may pass up lthe pipe i even with comparatively small difference in pressure, until the liquid level in the evaporator has been lowered to the hole p3. Q

The uppermost 4hole p is preferably ar-I ranged at such a height that it will never be covered by `the liquid when the maximum quantity of condensate accumulates in the evaporator, which results at the lowest temperature of the condenser cooling water. The lowest hole p3 is preferably arranged at such a height that it is belowthe level of the liquid when the amount ofV condensate a'ccumulated at the end Aof a heating period is at the minimum, asfor instance whenv the condenser cooling water is at missible temperature.

The holes p and p2 are fine bores, the total'.

area of which is not suflicient to permit the necessary outflow of vapors produced during the beginning of the absorbing and cooling action. These holes p and p2 permita suiiicient drawing-ofil of the vapors that a normal cooling effect is produced-during the beginning of the absorption or cooling'period when the absorption-is generally a rather rapid or violent one, and when the drop in temperature to be produced by. the evaporation is at a maximum.

During the later phase of the cooling period the cooling effect in ordinary apparatus tends to become less effective, due to the reduction in the absorption capacity of the liquor in the still-absorber, and due to the lowering of the temperature around the,

evaporator to a point more nearly thesame as that of thezevaporator. In the present construction the eiiect is rendered more uniform and the cooling period is extended because the hole p3, that is, the lowest hole, is

i' of such size that. after it-is uncovered by the liquid a considerably more intensive evaporation may take place, due to the larger total cross-sectional area of the uncovered gas outlet ports. The facility with which the liquid may be drawn back from the evaporator to 'the still-absorber, and automatically, is', however, the principal. advantage of the appa- In 'apparatus constructed in accordance with the patent above referred to, -it was necessary to repeatedly pourvboiling water into the heating vessel in the evaporator until the whole quantity o f liquid had been passed from the evaporator tothe still-absorber.

In the present construction considerably less vheat need be employed in order to return all of the liquid.l For instance, it is suilicient to heat the' evaporator with an electric heating element, or by a gas flame in which the action of h eat is more gradual than where boiling water is used. Instead of returning all 'of the liquid from the evaporator,

the highest per-..

. rator until the hole p3 is uncovered.

.ter which is used during the cooling it is 'permissible with the present invention to return to the still-absorber only the lowerV llayers of liquid in the evaporator. -Most of the water in the evaporator will bein the liquid,it is evident that this may be done by establishing the desired high pressure difierence between the evaporator and the absorber, as for instance, by repeatedly pouring boiling water into the cell/nl Aor by forcing very cold waterthrough the pipe c of the still-absorber. It is only essential that the total areas of the holes p and p2 shall not exceed the area of the singlehole employed in the construction shown in Patent 1,535,758. The practical working of the new `device may be effected by providing for five to ten minutes the flow throughthe vcooling pipe c of the normal proportion of cooling water which'was needed during the process of boiling, and -after the apparatus has been switched over to cooling phase. Thus, in the still absorber, there is produced'a sufficiently low pressure which cannot be neutralized at once by vapor passing through the holes pf and p2, and 'as a consequence, liquidis `returned from the evapo- In apparatus in which the switching over from boiling' phase to cooling phase is performed automat1cally by suitable control mechanism', it is not necessary with the present iuvention to do anything other than tol leave ,unaltered the rate of flow of cooling water for a short period, for instance, ten minutes after theboiling of water being still.

Even if the automatic reduction of the quant-ity of cooling waterI for the cooling process is effected at the moment of shifting over from heating to cooling phase, still the areas of the holes p' and p2 might be such that even the small quantity of cooling wai pel'ioi will produce ,the desired difference in pressure, whereby the outflow of gas cannot take place through. the holes p" and 712, and a pressure difference, will be effected which will cause the return of liquid to the stillabsorber until the level reached. Obviously, the 'holes is not in any way dependent upon whether the shifting over lfrom heating to cooling phase is effected automatically or manually.- Inthe drawings thereV is shown only a single pipe i for the return of fluid from the4 evaporator to the still-absorber, but it will of course bev evident that theremerely switched over to the onefor each port in-the evaporator.l

iss

period has cnded,.thc flow llt) of the hole p3 is v the dimensioning of4 In Figures 3 and-.4 'of the vdraw-ring Ijhave shown the combination of the rerigerating apparatus with special heating means'r for the evaporator Figure 3, showing heatingby electric means, while Figure 4 shows heating by means of a burner r. Q Y

- Having-thus described my invention, what i is claimed and desiredto be secured by LettersA Patent is and conduit means for deliveringluid from the-evaporatorV to the still-absorber, said conduit means having a terminal portion at'the lowest part of the'evaporator and having a plurality .of openings in` the vwall thereof, and at Vdifferent elevations.

2. A refrigerating apparatus including aA still-absorber, an evaporator, a condenser, and conduit means'for delivering luid from Athe evaporator to the still-absorber, said conduit means having a terminal portion at the lowest partofthe evaporator and having a plurality of openings in the wall thereof, and at different elevations 'above said terminal portion, at least'the lowest of said openings being disposed belowv the level of the liq 'd at the end of the heating period of the still-absorber.

' 3. A refrigerating apparatus including a still-absorber, an evaporator, a condenser,

and conduit means for delivering fluid from the evaporator to the still-absorber,- said conduit means having a terminal portion at the lowest portion' of the evaporator. and

having a plurality of openings in the wall thereof, and, at different elevations above said terminal portion, the lowest of said openingsbeing disposed below the level of the liquid at the end of the heating period of the still-absorber, and the total cross-sectional area of the hole or holes above the s i having a plurality of openings in the Wall thereof, and atfdilerent elevations above liquid level in the evaporator at the end of the heating period beinginsuliicient to permit the normal escape of gas from the evaporator during the beginning of the cooling period, whereby liquid from the lowest portion of said evaporator isfforced from the' latter through said conduit means.

4. A re'igerating apparatus lincluding a still-absorber, an' evaporator, a condenser, and conduit means for delivering fluid from the evaporator vto the still-absorber, said conduit means having a terminal portion at the lowest portion of the, evaporator and said terminal portion, the lowest of .said

' of the still-absorber,

l openings being disposed below the -levelv of the liquid at' the end of the heating period Y the total cross-sectional area of the hole or holes above liquid level at the end of the heating l. A refrigerating .apparatus including` astill-absorber, an evaporator, a condenser,

period being lessv than the total cross-sectional area of. the -hole or holes below said leve' v 5i. Arefrigerating apparatus including astill-absorber, an evaporator, a condenser.'

conduit means for` delivering fluid from the means having a terminal portion at the lowportion, and means for producing a sudden vrise of pressure withinthe evaporator.

6. .A refrigerating apparatus including a st-1llabsorber, a.n evaporator, a condenser,

evaporator to the still-absorber, said conduit est portion of tl1e eva1)oiato1, and-having a, plurality of openings in the wall thereof, and at different elevations above said terminal conduit means for delivering liuid from the still-absorber, an evaporator, a' condenser,

conduit means for delivering fluid from the evaporator to the still-absorber, said conduit mea-ns having a terminal portion at the low-v est portion'of the evaporator and having a plurality of openings in the wall thereol', and at different elevations above said terminal portion, and heating means for the evaporator to thereby etl'ect an abnormal rise in pressure in the evaporator and the return of liquid from the latter through said'conduit means to the still-absorber.

8. The method ot' effecting the return of" liquid from an evaporator to an absorber, which consists in varying the area of the gas outlet ports of the evaporator in accordance with the liquid level therein, high liquid level pressures are developed in the evaporator resulting in the forcing of liquid from the latter.

9. An evaporator for refrigerating apparatus o f the intermittently operating absorption type, means for delivering liquefied refrigerant tothe bottom thereof, and an open ended outlet conduit leading .Said chamber and having a plurality of openings in its wall within said chamber above the lower end of said conduit and of dil'crwhereby .atA

lll)

.having an evaporation chamber,

from the bottom of ent areas, the lowest ofsaid openings being of thellargest area Aand one or more of said openings being disposed below the normal high liquid level in said 'stillabsorbeiz 10. An evaporator having a conduit yfor the delivery of gas from the top in. (he normal operation and liquid from the lower part under abnormal conditions, said conduit having aplurality of apertures in thc- .wall thereof .of different cross-'sectional areas, and above the lower end of said conduit-,one ofsaid openings being disposed below the high liquid level in still absorber under normal operating condi-A the still absorber, tions. A f still absorber fory a short period following 11.-'lhe methodof operating a refrigerthe end 'of the heating-period whereby an ating apparatus of the'intermi'ttently acting abnormal difference in pressure between the -and'abnormally cooling the 10 5 absorption type, which. method consists instill absorber andthe evaporator is eected providing the evaporator with 'a gasoutlet of restrictedareato permit gas escape under testimonywhereof I 4afix'my signature.v normal operating conditicms, and a. lower ,i I

level liquid outlet, both outlets delivering 'to` v- (SUlHENZ BAYER.

and liquid is sucked fromtlie evaporator. 15

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