US1882257A - Means and method of refrigeration - Google Patents

Description

Oct. 11, 1932. B, RANDEL I 1,882,257

MEANS AND METHOD REFRIGERATION Filed May 18, 1951 2 Sheets-Sheet 1 MEANS AND METHOD OF REFRIGERATION Filed May 18. 1931 2 Sheets-Sheet 2 Patented Oct. 11 1932 BO FOLKE RANDEL, OF SAN DIEGO, CALIFORNIA MEANS AND METHOD OF REFRIGERATION Application filedMay 18, 1931, Serial No. 538,090.

My invention relates to refrigerating means and apparatus of the so-called vacuum type. In this type of apparatus a refrigerating medium, as water, is evaporated in a vacuum, this evaporation causing heat absorption and refrigeration.

My invention is based upon formation of such a vacuum in a very simple manner. The following descriptive experiment will illustrate this simple manner of creating a vacuum.

Assume a bottle completely filled with water, from which all air has been driven out. Now, assume this bottle turned upside ll down and with the opening connected to a liquid pump.

Now, if pump is started, the water will be pulled out of the bottle and a space of vacuum will be created. As the water is Withdrawn,

pressure is reduced and evaporation of water will take place to fill the space above the surface. The evaporation will cause heat absorption and cooling of the remaining water In my apparatus I do this continuously and also remove the vapors formed, and once a certain point is reac ed, condense the va pors removed and return same to the evaporator in liquid form, again to be evaporated.

Any liquid may be used in my apparatus,

80 but for simplicity of description,-water will be assumed to be the medium used. Other liquids which may be mentioned as suitable are alcohols, ethers, hydro-carbons, etc., and such liquids may be especially suited where a lower temperature than 32 degrees Fahrenheit is required.

In Fig. 1, I illustrate in diagrammatic form an arrangement suitable to my purpose, and in Fig. 2, I illustrate a slight modification of one part of the apparatus. In Fig. 3 I show a structural modification of Fig. 1. The several parts are conventional and may i be constructed in many different ways.

The principal arts of my apparatus are evaporating cham er 1,condensing chamber 2, circulating pump orcompressor 3, andvapor entraining column 4.

Assume water as refrigerating agent, the

operation of the apparatus is now as fol 53 lows Beforepump 3, driven bymotor 3a is started, water fills the apparatus up to level A. All the air is removed so that space above this line A is filled with water vapor under the pressure as a resultant of the temperature. The entire apparatus is sealed so as toprevent any inflow of air, and an advantageous construction will be to also enclose the motor with the sealed parts. If we assume a temperature of 70 degrees F. throughout the parts, then the vapor pressure in the vapor space will be approximately 0.3626 lbs. absolute, thus the apparatus operates under an initial vacuum of 29.18 inches of mercury.

In larger installations,chamber 2 may be vented in such a manner as to prevent inflow of air or the breaking of the vacuum, but with provision to discharge vapors or liquid as desired when pressure in this chamber is above pressure outside of same. Also, a separate vacuum pump may be added to maintain necessary vacuum and remove any air which may leak into the system. In the following description it is assumed that the apparatus is sealed and absolutely tight and with all the air removed, but I do not limit the construction to this arrangement. Thepump 3, which maybe of any construction, centrifugal, gear, rotary,-etc., is now started. Liquid below line A in chamber 1,pipe 4 andpipe 6 will be transferred over tochamber 2. This chamber communicates throughpipe 5 and nozzle 8 with entrainingcolumn 4. Nozzle 8 discharges through Venturirestriction.9 and liquid passing through 5 and 8 will entrain vapors inchamber 7 pulling same along throughcolumn 4 to suction pipe 10 ofpump 3.

Now, nozzle 8 is restricted so as to permit building up of the pressure in-condensingchamber 2 sufficient to compress vapors present there, and by cooling same by cooling coil 2a, condensing same to liquid stat It is seen that by this action all the vapor may be condensedinchamber 2, thus filling same with liquid to level B. The liquid is thus withdrawn from chamber 1 and the cubical contents or volume of the diiferent chambers and interconnected ipes are so figured that whenchamber 2,p1pe 5 and entrainingcolumn 4 are entirely, or nearly so, filled with liquid, the level A above chamber 1 is lowered to level G. The liquid being practically incompressible this level C will be maintained, and any addition to the liquid in thecombination 2, 4 and 5, will force this additional liquid through pipe 11 with seal 11aand into chamber 1, notwithstanding pipe 11 is on suction side of pump.

When this phase of the operation is reached three conditions will arise.

F irstno further liquid can be drawn from chamber 1 over to suction ofpump 3.

Secondall the liquid handled by the pump will circulate throughpipe 12,chamber 2,pipe 5, entrainingcolumn 4 and back to pump through pipe 10.

Third-the removal of part of the liquid from chamber 1 will lower the pressure in same and will cause evaporation from the remaining liquid. If we assume that the vapor volume in 1 and connectingpipe 6, and alsospace 7 is enlarged by the removal of liquid to ten times its original volume, which may be easily arranged for, then the pressure being practically in inverse proportion to the volume, this pressure will drop from the original, or from 0.3626 to 0.03626 lbs. abs., provided of course no evaporation of the liquid took place. However, as soon as pressure drops evaporation will take place with absorption of heat from the liquid, and from the surrounding objects, which evaporation will cause increase of pressure to correspond to the desired temperature of the object to be cooled. Using water as agent, temperature may reach 32 degrees with a drop of pressure to 0.0886 lbs. abs. per sq. in.

Vapors formed in chamber 1 will pass throughpipe 6 tochamber 7, there to be entrained with the liquid coming throughpipe 5. The entraining column may be surrounded withcooling jacket 40 where cooling water is used to assist in condensing the vapors. Vapors not condensed here, will be condensed incondensing chamber 2 under the increased pressure there.

Now, any vapors pulled in at 9 and condensed in 4 or 2 will add to the liquid on the high pressure side and will force a. similar amount ofliquid through pipe 11 to evaporating chamber 1, thus maintaining a constant supply of new liquid to be evaporated. The entraining nozzle 8 may discharge downwards as shown, pulling along va ors which will travel downwards with the iquid similar to air bubbles in liquid compressors and barometric condensers, or the nozzle may discharge upwards or horizontally as desired.

I have shown in evaporatlng chamber 1 capillary tubes or columns 1a. These tubes or columns are made of porous-material as unglazed tile, and the purpose is to increase the area of evaporating surface by capillary action. Liquid will be sucked upwards into the material of these elements and thus increase the area of liquid surface.

In Fig. 2, I show a modification of evaporating chamber 1 to increase the area of liquid surface. Liquid drawn out of the chamber through pipe 11 is checked by conventional ball check 13 preventing flow back to the chamber through this line. Liquid flowing back to chamber must flow through pipe 17, ball check 14 and over pans 16 inside said chamber 1. Any suitable check valge arrangement to direct the liquid can be use Many other arrangements of the apparatus may be arranged and I include all such in my invention to perform the work of refrigeration according to my principle of operation.

It is to be noted that although two dif- :Eerent pressure zones are present during operation, a higher pressure and a lower pressure, no expansion valve is used. Refrigerant is fed to low pressure zone from high pressure zone without the use of expansion valve. The apparatus may be built without the use of any valves, float or pressure operated. The principle of feeding liquid refrigerant to an evaporator is entirely novel and not employed in any other refrigerating apparatus.

In Fig. 3 I show a slight structural modification.Parts 5, 6, 7 and 8 of Fig. 1 are shown in a lower position and below the liquid level A. The parts moved down are denoted 5A, 6A, 7A, 8A and 45A, and functionsimilar to 5, 6, 7, 8 and 4b as shown in Fig. 1. This modification is indicated-that my apparatus may be constructed in many diflerent'ways to carry out the same principle of operation.

I claim I '1. A method of refrigeration comprising the removal of part of a'liquid contained in a vessel, thus creating a space of lowered pressure in said vessel, evaporating. part of the liquid remaining in said vessel into said space of lowered pressure with resultant absorption of heat, passing said produced vapor to a condensing space, liquefyingsaid vapors and returning liquid to said vessel to make up for the evaporation in said vessel.

2. Creating a low pressure in an evaporating vessel in connection with a condensing vessel by transferring part of aliquid from the first to the second vessel, evaporating the liquid remaining in said evaporating vessel taining a liquid to be evaporated, a condensing chamber with means attached to cool and condense a vapor, communication means be-= tween said evaporating chamber and said con densing chamber, pump means to transfer liquid from a lowered pressure in said evaporating chamber against a raised pressure in said condensing chamber through said communication means, means to pass liquid from said condensing chamber through a vapor entraining chamber, communication means between said vapor entraining chamber and vapor space of said evaporating chamber, means to mix and entrain vapors produced in said evaporating chamber in the liquid passing through said entraining chamber and means to pass said mixture of vapor and liquid to suction side of said pum means and further means to return to sai evaporating chamber sufficient liquid to compensate for loss due to evaporation in same, thus maintaining a constant liquid level in said evaporating chamber during operation of the apparatus.

4. A method of refrigeration removing vapors from an expansion space by entraining same in a moving liquid column, condensing said vapors and returning refrigerating liquid to said expansion space by volumetric displacement and without the employment of an expansion valve between the condensing space and the evaporating space.

5. A refrigerating apparatus of the vacuum type, a condensing space and an evaporating space, means to transfer vapors from said evaporating space to said condensing space by entraining said vapors in a liquid, and means to return refrigerating medium from said condensing space to said evaporating space by volumetric displacement.

6. In a' refrigerating apparatus of the vacuum type, an evaporating space and a con- (lensing space and means to create a lowered pressure in said evaporating space by transferring liquid from said evaporating space to said condensing space, thus increasing the volume of the vapor space in said evaporating space.

7. A method of refrigeration, transferring liquid from an evaporating space-to a condensing space thus increasing the volume of the vapor space in said evaporating space,

causing evaporation of the remaining liquid,

and constantly maintaining such evaporation by removing the vapors produced by entraining same in a moving body of liquid.

In testimony whereof, I have hereunto set my hand at San Diego, California, this 14th day of May, 1931.

' BO FOLKE RANDEL.

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