US2134996A - Refrigerating machine of the absorption type - Google Patents

Description

Nov. 1, 1938. A. BIKKERS I 2,134,996

REFRIGERATING MACHINE OF THE ABSORPTION TYPE Filed April 22, 1957 ,9 a) \s //A fl'exa/aderfig y latory pipe and thence to Patented Nov. 1938 UNITED sT TEs 2,134,996 BEFRIGERATING MACHINE OF THE ABSORPTION TYPE Alexander Bikkers,

Netherlands Application April 22,

The Hague,- Netherlands, assignor to Willem Frederik Pocl, Haarlcm,\

1937, Serial No. lsssss In the Netherlands April 29, 1936 5Claims.

This invention relates (to refrigerating machines of the absorption type inwhich the pressures are equalized by means of the addition of inert gas;

In applicant's Patent No. 2,020,763 it has been suggested to provide both the absorber and the evaporator with an individualcirculatory pipe and to interconnect said pipes by a suitable conduit, through which refrigerant vapour from the circulatory pipe of the evaporator difiuses into that of the absorber. This patented construction has the inconvenience that a'certain amount of heat is necessarily transmitted from the absorber. through its circulatory pipe, to the second circuthe evaporator, whereby the efliciency of the machine is impaired. Moreover, difiusion is a very slow process, so that the capacity of the machine under consideration is relatively small.

My present invention has for its object to meet the objections stated. With this object in view, I

- matic drawing. on which:

suggest to provide the absorber with a circulatory pipe, part of which is in direct contact with a wall portion of the evaporator and communicates therewith through a suitable opening, and to provide the evaporator with bafiles along which the liquid refrigerant from the condenser is adapted to flow down so as to produce, within the evaporator, eddies whereby the refrigerant vapour is compelled to flow across said opening. Owing to the fact that a rich mixture of inert gas and refrigerant vapour is thus caused to.continuously flow across the opening in the evaporator wall, said vapour is adapted to diffuse into the circulatory pipe of the absorber through a conduit, the length of which is practically nil, whereby a comparatively great amount of said vapour ,is'conveyed perunit of time. I

It will be appreciated that the wall portion, which is common to the evaporator and the circulatory pipe of the absorber, may be very thin, sinceequal total pressures obtain on either side of said wall portion.

If the density of the refrigerant vapour, for instance ammonia, is smaller than that of the inert gas, for instance nitrogen, it is advisable to provide the aforesaid opening near the top of the evaporator, as under said circumstances the refrigerant has the natural tendency to rise. If, however, the inert gas is hydrogen, or helium, it is preferred for said opening to be located near the bottom of the evaporator.

In order that my invention may be well understood, reference is bad to the annexeddiagram- Fig. 1 is an elevation, partly in section of a refrigerating machine in accordance with the invention, and

Fig. 2 is an elevation, partly in section of a modified evaporator.

In Fig. 1', the numeral 2 designates the insulated wall of a cabinet, the interior space I of which is to be cooled.

Mounted outside said cabinet is a boiler or gas expelling vessel 3 provided with a heating device 4. This vessel is connected near its top with a liquid separator 5 having a plurality of baiiles 6 and communicating, through 'a' pipe 1, with the condenser 8, of which the lower and the upper portions are connected with the evaporator l2 through pipes 9 and I3, respectively.

The evaporator l2, which is mounted within the cabinet 2, is provided with two horizontal partitions I, each having plain openings I6 and also openings IS with upturned edges. The openings in the one partition are disposedin staggered relation to those in the other. Near the top, one of the side walls has an opening ll, through which the evaporator communicates with the descending section 22 of pipe l8, I9, 20, 2|, 22, 23, 24, the section I3l9 ,of which acts as an absorber. At the junction between sections 24 and I8, said pipe opens into a vertical conduit 25, which has a horizontal extension 26 merging as' at 21 into, the boiler 3 and is connected with the bottom portion of the evaporator I2 by a pipe 28.

Near its bottom, the boiler 3 is connected, through a conduit 29, with an auxiliary gas expeller 30 provided with a heating device 3| and communicating at its top, through an ascending pipe 32, with a vessel 33 mounted inside the vapour space of the boiler 3. Said vessel 33 is con-\ nozzle opening into a mixing cone 38, which,

merges into a discharge cone 39 so as to form an injector, it being understood that said cones form parts of the circulatory section pipe I8. Pipe 34 is, through a substantial partof its length, enclosed by-pipe '26, with which it forms a heat exchanger. Another heat exchanger is formed by sections 20 and'23 of the circulatory pipe.

Assuming the boiler 3 to be partly filled with a strong aqueous solution of ammonia, the remaining space of the machine to be filled with compressed nitrogen, the modus operandi will be as follows.

Owing to the .heat developed by. the device 4,

a circulatory.

' through the plain openings N5 of the upper parby the arrows.

tition onto the lower partition l4, through the plain openings 16 of which, part of the liquid may fall onto the bottom of the evaporator.

In the vicinity of openings IS a very low temperature will be produced by sudden evaporation of 'the liquid refrigerant. Owing to the openings l5 having upturned edges, no liquid refrigerant can flow therethrough, so that the temperature near these openings will not so abruptly be reduced, the result being that eddies and vortexes are produced in the mixture of inert gas and refrigerant vapour, as indicated It will thus be understood that a rich gaseous mixture will continuously flow across the opening l1, so that the refrigerant vapour has ample of opportunity to diffuse into section 22 of the circulatory pipe, where it mixes with thepoor gaseous mixture flowing therethrough in downward direction, so as to be conveyed to the absorber l8, l9.

Any liquid refrigerant collecting on the bottom of the evaporator is discharged through pipe 28 into conduit 25.

The heater 3| causes refrigerant vapour to be freed by the solution contained in the auxiliary boiler 30. Thereby, an emulsion of vapour and liquid is produced, and this emulsion rises through the narrow ascending pipe 32, whereby poor liquor is discharged into vessel 33.

From this vessel, the poor liquor flows through pipe 34, 35, 36 into the absorber section l9, whence it flows by gravity into section l8, where it absorbs the refrigerant vapour supplied thereto by sections 22, 23, 241. The rich liquor thus produced in the absorber is returned, through the conduit 25, 26, 21., to the boiler 3.

The refrigerant vapour collecting in the upper portion of vessel 33 is discharged into the aborator.

sorber section l8 through the injector 31b, 38,. 39, whereby the required circulation in the circulatory pipe is produced, it being understood that the pressure obtaining in vessel 33 is sufflciently in excess of that in the absorber in order that the injector may operate. This circulation causes the poor gaseous mixture coming from the absorber to flow through pipe 22 across opening H, where it can take up refrigerant vapour from the evaporator and convey it to the absorber.

Since the hot section of the circulatory pipe is in heat exchangin relation with the cold section 23, it is impossible for any appreciable amount of heat to be transmitted to the evap- Pipe l3 equalizes the pressures obtaining in the condenser l and in the evaporator l2, respectively. This is necess ry in order that the evaporator may be continuously supplied with liquid refrigerant and, consequently, the eddies required for conveying refrigerant vapour to the openings I'l maybe produced without interruption..

Fig. 2 shows an alternative construction of the evaporator. The evaporator 12 here is provided with. a plurality oi sloping baflles 40 'mounte-l edges of the battles,

- the addition of inert ing with at different levels and in staggered relation with one another in such a manner that 11-11116 refrigerant discharged by pipe 9 flows from he top portion of the upper baflle to the lower portion thereof, thence 'falls on the next baflle, and so on. Consequently, very low' local temperatures will be produced in the vicinity of the lower owing to the sudden evap-. oration of liquid refrigerant, thus causing the required eddies to set up. In this alternative construction, the opening I1 is provided near the bottom of the evaporator, since this type of evaporator has been designed for a refrigerating machine in which hydrogen or helium is used as the inert gas.

What I claim is:

1. In a continuous absorption machine in whichthe pressures are equalized by means of gas, a gas expeller, a con-- denser, an evaporator and an absorber intercon nected in series, a circulatory pipe on the absorber and partly contacting with a wall portion of the evaporator, an opening in said wall portion to establish communication between the evaporator and circulatory pipe, and baflle means provided in the evaporator, said baifle means being adapted to compel liquid refrigerant discharged from the condenser into the evaporator to flow towards the bottom of the evaporator in such a manner. as to produce eddies in the gaseous mixture and cause refrigerant vapour continuously to flow across said opening.

2. In a continuous absorption machine containing an inert gas equalizing the differences in the refrigerant pressure, a gas expeller, a condenser, an evaporator and an absorber, a cir culatory passage on the absorber partly contacting with a wall portion of the evaporator, an opening in said wall portion communicating with the said circulatory passage and baille means provided in the evaporator, said baffle means being provided with apertures so formed that the liquid refrigerant discharged into the evaporator can fall through only some of said apertures, but is positively prevented from falling through others, in such a manner as to produce eddies in the gaseous mixture within the evaporator and cause mixture rich in refrigerant to flow across said opening.

3. In a continuous absorption machine containing an inert gas equalizing the differences in the refrigerant pressure, a gas expeller, a condenser, an evaporator and an absorber, a circulatory passage on the absober partly contacta wall portion of the evaporator, an opening in said wall portion communicating with the said circulatory passage, and baflle means provided in the evaporator, said baflle means comprising a horizontal partition provided with an aperture having upturned edges, preventing the liquid refrigerant discharged into the evaporator from falling through the said aperture, and further provided with an aperture the edges of which are located at a lower level than those of the first mentioned aperture to permit the said liquid to fall down through it, the said apertures arranged in such a manner as to produce eddies in the gaseous mixture within the evaporator and cause mixture rich in refrigerant to flow across said opening. 1

4. In a continuous absorption machine containing an inert gas equalizing the differences in the refrigerant pressure, a gas expeller, a condenser, an evaporator. and an absorber, a circulatory passage on the absorber partly contact- 1 ing with a wall portion or the evaporator, an opening in said wall portion communicating with the said circulatory passage and baflle means provided in the evaporator, said baflle means comprising a plurality of sloping baflle walls, each mounted so as to leave free a gas passage both at the higher and at the lower side of it.

5. In acontinuous absorption machine containing an inert gas equalizing the differences in the refrigerant pressure, a gas expeller, a condenser, an evaporator and an absorber, a circulatory passage on the absorber partly contacting with a wall portion of the evaporator, an opening in said wall portion communicating with the said circulatory passage, and baflle means provided in the evaporator, said baflle means being adapted to compel liquid refrigerant discharged from the condenser into the evaporator to flow towards the bottom of the evaporator in such a manner as to produce eddies in the gaseous mixture and cause mixture rich in refrigerant continuously to flow across said opening, and means arranged for supporting circulation in the circulatory passage and operated by pressure generated outside the absorber and evaporator.

ALEXANDER BIKERS.

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