US2117506A - Refrigerating apparatus - Google Patents

Description

May 17, 1938. G, D. REINHARDT REFRIG ERATING APARATUS Filed July 51,v 1936 (fOr-'- .M R mm mw W@ im m rv ATTORNEY.

Patentedv May 17, 193s PATENT OFFICE.

2,117,506 REFRIGERATING APPARATUS" George D. Reinhardt, San Antonio, Tex.

* Application July 31,

3 Claims.

This invention relates to refrigerating apparatus.

The main object of the invention is to secure higher efficiency in refrigerating effect with minimum evaporating surface and a material reduction in the required motor power and compressor capacity.- y

Another object is to prevent pre-expansionand wasted evaporation of the liquid vrefrigerant whereby to make available` for useful work all vaporization of the liquid.

Ar further object of the invention is to increase the velocity of the refrigerant at the lower temperature in the enclosed evaporator space Awhereby to gain in heat transfer.

A still further obj ect is to produce a positive flow of the refrigerant in the evaporator coil by means 0f an ejector issuing from a high-pressure fluid coil through an interposed nozzle. i

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily 'understood from a reading of the following specification and 25. by reference to the accompanying drawing?, in

which an example of the invention is shown, and

wherein: y

Figure l .illustrates a schematic general assembly of accumulator unit and evaporator coil system and the directly correlated parts of the apparatus;

Figure 2 is a view, on an enlarged scale, showing the lower portion of the accumulator shell in section and details of the ejector valve and communicable connections between lthe accumulator unit and the evaporator coil; and q Figure 3 is a cross section through the ejector nozzle and valve cylinder.

Referring to the drawing, the numeral I0 indicates a main header pipe or manifold constitutingy a part of the evaporator unit or coil of the apparatus, said pipe or manifold Il] having an inlet pipe 2 atone end and a series 'of riser pipes lor branches Il leading from its opposite end and converging together into a header pipe or manifold 3. The pipes I-I may be formed and arranged inany convenient shape that will facilitate the flow of the refrigerant therein, whereby to prevent pockets or traps Where liquid might accumulate and also to facilitate the heat transfer between the confined refrigerant within vthe evaporator unit and the medium surrounding the unit.

Interposed between the inlet pipe 2 `and the outlet header or manifold 3 of the'evaporator unit 1936, Serial No. 93,701

(Cl, (i2-126) is a hollow drum 4 of a size several diameters` larger than the header or manifold 3 and of such cubical dimensions as to permit proper separation of the liquid and vapors entering the drum through said header or manifold 3. An outlet pipe 5 leads from the upper portion of the drum 4 `to the inlet of a compressor (not shown) whereby suction is created in said pipe 5 to draw thespent vapor or gas from the evaporator.

Within the hollow accumulator shell or drum 4 is a helically wound cylindrical pipe coil 8 whose upper or inlet end portion extends out through an opening in the shell or drum and is connected to a throttling device or control valve 1, from` the opposite side of which latter a pipe 6 leads to a reservoir or a receiver of the liquid refrigerant (not shown).

The lower or outlet end portion of the pipe coil 8as shown, is screw-threaded and connected to a coupling member or thimble 9, which in turn is connected to a nozzle member or ejector I3 having a constrictedpassage I4 therethrough for a portion of its length, beyond which is a ared or divergent throat or outlet passage I5, said constricted passage I4 and flared passage I5 being in axial alinement with each other and the passage I4 communicating with the lower end of the pipe coil 8 through the coupling thimble 9.

Surrounding the nozzle member or ejector I3 is a hollow cylindrical member I6 whose upper end is closed by a wall, except for an axial opening in said wall, through which the nozzle member or ejector I3 is inserted. As shown, the nozzle member is provided with an annular shoulder I 3' vwhich rests on the end wall of said cylindrical member I6, whereby to support the pipe coil 8. In this connection, it may be here noted that the nozzle member or ejector I3 need not necessarily be secured in the end wall opening of the cylinder I6 with a relatively tight or sealed t but need only be inserted loosely therein with the shouldered portion I3' resting on the end wall of said cylinder I6.

The lower end of the cylinder I6 is open and, as shown, has a screw-threaded attachment to a coupling member or lthimble I9 whose' lower end. portion has a screw-threaded attachment with the 4upper end portion of the inlet pipe 2 of the evaporator unit, 'which pipe extends up into the lower portion of the. accumulator drum or shell 4, the pipe being welded or otherwise secured to the bottom of the shell or drum 4 with a leaktight jointure'.

Preferably, the upper end portion of the nozzle member or ejector I3 is provided with a counter- `rated and turned into gas.

bore I2 in which is placed a filtering screen or element through which the liquid from the pipe coil 8 passes before it enters the restricted bore Il of said nozzle member or ejector I3. The cylinder I6 surrounding the nozzle member or ejector I3 is provided with a series of apertures Il through which communication is established between the interior of said cylinder I6 and the surrounding space in the lower portion of the accumulator drum or shell 4.

In the operation of the apparatus shown in the drawing, the liquid refrigerant, for example, ammonia. liquid, is passed under pressure from the reservoir or receiver (not shown) through the pipe 6 and controlling valve 1, into the pipe coil 8. From the coil 8 the liquid under pressuie is forced through the restricted passage I4 of the nozzle member or ejector I3,`Whence it is delivered into the divergent or flared passage I5 of the nozzle member or ejector I3, by the provision of which the liquid expands into the pipe 2 which is of somewhat larger diameter than the coiled piping thereby reducing the pressure but increasing the velocity of the iiuid.

Obviously, as the liquid expands in the pipe 2 evaporation occurs, whereby the header or manifold III and evaporator coil pipes Il become filled with the expanded and vaporized ammonia liquid, that is to say, the header or manifold and coil pipes are lled with a mixture of ammonia liquid and gas, obviously under relatively low pressure.

In other words, the evaporator is operated in flooded condition, as it is termed in this particular art. .f

The,e'xpanded liquid and the vapor or gas therefrom inthe evaporator pipes boils over and into the accumulator shell or drum' 4, through the header or manifold 3. Being in the form of liquid and gas, the liquid portion of the refrigerant entering the accumulator shell or drum 4 drops to the bottom of the latter while the lighter gas is `drawn oi from the shell or drum 4 through vthe pipe 5 by the suction of the compressor.

'Any entrained moisture in the boiled over refrigerant within the shell or drum 4, upon coming in contact with the coil 8 which naturally is heated by the compressed high pressure liquid therein, gives up its latent heat and is re-evapo- This produces a dry saturated gas which has the effect of cooling the coil 8 and the liquid therein before the gas is drawn into the pipe 5 by the suction of the compressor. ,Any liquid not re-evaporated falls to the bottom of the accumulator and is drawn back into the evaporator coil, through the apertures I8 in the cylinder member or aspirator tube I6, by the suction produced by the jet from the nozzle member or ejector I3, whence it is circulated with the liquid from the nozzle member or ejector I3 through the evaporator coil or piping.

Positive ow of the Allow pressure refrigerant in the evaporator coil or piping is produced by the liquid jet from the high-pressure coil, as just above noted, said jet producing a high velocity of the liquid when leaving thenozzle and forcing all liquid ahead of it into the evaporator, which, obviously, is at a relatively low pressure.

In a ooded type evaporator coil the entire coil,

' as herein above noted, is fllled with low-pressure refrigerant, which, obviously, is boiling due to the heat being absorbed from the surrounding medium, which, for example, may be water, brine or other media. Gain in. heat transfer is accomplished due to the factthat the refrigerant flowing at high velocity through the evaporating coil prevents formation of large bubbles so that the.

-a small amount of evaporating surface per pound of refrigerant used is provided and at the same time 'it makes for smaller and more compact machines and coolers, as well as reducing the required m'otor power and compressor capacity.

What I claiin and desire to secure by Letters Patent, is:

1. In a refrigerating apparatus, an accumulator comprising a closed vertical hollow shell and a vertical pipe coil therein, said shell having an outlet leading from its upper portion to the suction side of a compressor, a manifold located below said accumulator shell, a pipe connected communicably at one end to the inlet end of said manifold and having its opposite end portion extended vertically into the lower portion of said accumulator shell, an annularly apertured tubular aspirator member disposed vertically within the shell, said aspirator member being connected communicably at its lower end with said manifold-connecting pipe and having an axial opening in its upper end, a vertical nozzle member inserted in said aspirator member through the upper end opening of the latter, said nozzle member being connected to the lower end of said pipe coil within said shell and having a downwardly flared throat and a restricted axial passageway between the throat and said pipe coil, the throat outlet of the nozzle member being located below the apertured portion of the aspirator member, evaporator tubing connected at one end to the outlet end of said manifold, and another man i. fold connecting the opposite end of said evaporator tubing communicably with the interior of said accumulator shell intermediate the` ends of. the latter.

2. In a refrigerating apparatus, an accumulator shell having a communicable connection with the outlet of an evaporator whereby to receive the overflow of refrigerant from the evaporator, the liquid separated from the vapor in the overflow precipitating and accumulating in the lower portion of the shell and the vapor being withdrawn from the upper portion of the shell, a pipe leading from the bottom of the shell to the refrigerant inlet of the evaporator, said pipe extending vertically into the shell, an aspirator tube com-` municably attached at its lower end to said pipe withinsaid shell, said aspirator tube having an annular series of apertures therein but being otherwise closed, a nozzle member extendingy lower end below the annular series of apertures' of said tube, said nozzle member having an axial passageway therethrough, the upper portion of which is restricted and the lower portion flared downwardly to the lower end of the member, and a supply pipe from a source of liquid refrigerant under high pressure extending downwardly in said accumulator shell and communicably connected at its lower end to the upper end of said nozzle member.

3. In a -refrigerating apparatus, an accumulator shell connected at its upper portion to an evaporator to receive the refrigerant overflow from the evaporator, the liquidseparation of the overflow precipitating and accumulating in said shell, a

pipe leading from the bottom of said accumulator au'msoer aspirator tube with its lower end terminating below the annular series of apertures of said aspirator tube, said nozzle member'hz'iving an axial ypassageway therethrough, the upper portion of which is restricted andthe lower' portion'aring 5 downwardly to the end of the. mernber.

GEORGE D. REINHARDT.

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