US2618132A - Refrigeration system with refrigerant cleaning means - Google Patents

Description

Nov. 18, 1952 F. M. POTTENGER, JR

REFRIGERATION SYSTEM WITH REFRIGERANT CLEANING MEANS Filed Aug. 30, 1948 REF L UX PORA TOR WATER PUMP 70 //V VE N T R FRA NC/S M POTTENGERJI: M

ATTORNEY Patented Nov. 18, 1952 REFRIGERATION SYSTEM WITH REFRIG- ERANT CLEANING MEANS Francis Marion Pottenger, Jr., Monrovia, Calif.

Application August 30, 1948, Serial No. 46,785

I The present invention relates to refrigeration systems including refrigerant cleaning means.

An object of the invention is to provide an improved refrigeration system including means for uid extraction medium for biological material,

such as glandular tissue, and the absence of water will prevent freezing of throttling devices, such as expansion valves, and will also avoid possible corrosion of metal surfaces.

Another object is to provide a refrigeration system in which the cleaning of the refrigerant is effected between the compressor and the condenser, so as to avoid deposit of oil in the condenser.

A further object is to provide a refrigeration system in which the same cleaning means will serve to remove both water and oil from the refrigerant.

' A still further object is to provide a refrigeration system in which the contaminants can readily be withdrawn from the system while the system continues in operation.

The invention further consists in the several features hereinafter described and claimed.

In the accompanying drawing, the figure is a diagrammatic representation of a refrigerating system arranged in accordance with the invention. y

In the drawing, I designates a refrigerating compressor of any conventional type, here shown to have a gas inlet or suction conduit II with the usual control valves Ila and II b, a gasdischarge conduit [2, a water jacket I 3, and a crank-case ll adapted to contain lubricating oil. The refrigerant may be any one of various kinds, such as ammonia, ethane, and halogenated hydrocarbons, including the freons among which is dichlorodifluoromethane (Freon-12). The compression of the refrigerant may be effected in one or more stages, depending on the nature of the refrigerant' The refrigerant is discharged from the compressor in v gaseous superheated condition and is generally contaminated with lubricating oil. To remove the'oil and other contaminants from the refrigerant, the refrigeration system includesa scrubbing or cleaning columnor tower l5 connected between the compressor discharge con 9 Claims. (C1. 62-117.75)

duit l2 and a condenser It. The column forms a fractionator or rectifier and is here shown to be of the packed type although the multiple plate or bubble cap type can be used. The column packing I! may be of any suitable type such as porcelain Berl saddles or, Raschig rings. The packing rests on a perforated plate l8 near the bottom of the column, leaving a chamber l9 therebelow. The top of the column is closed by a jacketed domed cover 20 clamped to the column and to an interposed perforated plate 2| which will prevent lifting of the packing by any sudden pressure surges. The cover jacket is connected by fluid-conducting pipes 20' adapted to receive a cooling liquid when the cover is used as a condenser, as hereinafter described. The lower portion of the column is enclosed by a jacket 22 the bottom end of which communicates with the compressor outlet conduit 12. At the upper end of the jacket 22 the column is provided with a ring or band of small feed ports or openings 23 for admitting the contaminated gaseous refrigerant into the column, the aggregate cross-sectional area of the ports being slightly larger than the cross-sectional area of the interior space of the column. The portion of the packed column above the gas feed ports constitutes a rectifier section. The column is preferably insulated, as by jacketing 24, so that the temperature of the upfiowing gaseous refrigerant will fall at an even gradient. A drain pipe 25 with a normally closed valve 25' is provided at the bottom of the column jacket 22 to discharge any oil which may collect in the jacket. The chamber I9 at the bottom of the column is connected by a drainpipe 26 with a normally open valve 26'. to an oil receiver 21, the latter having a drain pipe 28 with a manually controlled normally closed valve 28' to discharge any water or other accumulation from the bottom of the receiver atsuitable intervals. An oil discharge pipe 29 connects the receiver with a float valve 30, and a pipe 31 connects the float valve with the compressor. crank-case. Theintake of the oil discharge pipe 29 extends above the bottom of the receiver to avoid passage of water to the float valve and crank-case.

The condenser I6 is here shown to be ofthe triple tube type with a middle refrigerant passage and inner and outer coolant passages. One end of the middle passage of the condenser is connected to the reduced upper end of the column cover 20 by a conduit 32, the latter being provided with a suitable purger 33. The other charges li'quefied refrigerant through pipe 34 insight glass 44 has the usual valves 44.

3 to a branch fitting or T-fitting 35 to which valved sight glasses 36 and 31 are connected, the refrigerant being divided at the fitting 35 into two parts which flow through these sight glasses. The sight glasses 26 and 31 have normally open valves 36' and 31. The greater part of the liquefied refrigerant is returned through the sight glass 36 to the upper end portion of the column by a reflux'pipe38 having a trap loop 39, the end of the reflux pipe within the column being perforated to distribute the liquid and being spaced below the plate 2|. The reflux may constitute about of the total condensate in the case of ammonia; however, this proportion will vary with the refrigerant. The rest of the liquefied refrigerant passes through the valved sight glass 13'! to the upper end of a water-jacketed stand pipe 40, the lower end of which is connectedto a liquid receiver 4 I. In general, the proportion of reflux will depend on the relative flow resistance in the conduits branchin-gfrom the condenser .outlet. An overflow pipe 42 with a normally open valve 42' connects the condenser discharge pipe 34 with the upper end of the stand pipe 4!) to accommodateabnormal flow conditions.

The receiver 4l' for the liquid refrigerant preferablyhasa jacket 43, although hydrostatic pres- ;sure in the stand pipe 40 will usually overcome the pressure due to increased temperature of any gas in the receiver. The receiver has a sight glass 44 and dump valve 45, and may also be The A discharge pipe 41 extending upwardly from the receiver has aking valve 48. From the receiver 41 the liquid refrigerant passes through suitable utilization means 49 such as an evaporator, and the refrigerant returns in gaseous condition to the compressor inlet II by Way of a conduit 50. The evaporator may have therein a cooling chamber 49a for liquid refrigerant. The evaporator includes the usual throttling device, such as an expansion valve 49'- The discharge pipe is here provided with a purging connection 46.

shown to have a branch48 for drawing off liquid refrigerant from the system.

Cooling of various parts of the system is effected by a motor-driven water pump 5| which forces water first through the receiver jacket 43 (the coolest portion of the water circuit), up through the jacket of the stand pipe 43, successively through the inner and outer passages of the condenser I6, through the compressor jacket l3 by way of a pipe 52, and then through a pipe 53 to a cooling tower, not shown, the pipe 53 having a valve 53. A part of the discharge water may be passed by way of, pipes 54 and 55 through the jacket 2'! of the oil receiver 21, which should be the hottest point in the water system. The pipe 54 has control valves 54:; and 54band a drain valve 540, and the pipe 55 has a control valve 55a. If hot water or steam is available at the installation this may be used instead for heating the oil receiver. 7

In the operation of the refrigeration system, superheated gaseous refrigerant is delivered by the compressor through the discharge conduit I 2 to the lower end of the column jacket 22 and heats the lower walls of the column. The gas rises to the upper end of the jacket and passes into the column through the numerous small feed ports 23. The gas then flows upwardly through the packed column and the gas temperature falls at an even gradient. The contaminated gas rising through the column packing and the liquid refrigerantfrom the reflux pipe 38 .are re- 4 ebulliated many times, providing an efllcient cleaning or purifying action on the gas and causing the oil vapor or fog, and higher boiling point substances to fall to the bottom of the column. The oil, water, and other contaminants thus removed are collected in the receiver 21, and the oil is conducted to the compressor crank-case by way of the float valve 30. Instead of using a float valvethe oil maybe drawn off the receiver manually through the valved drain pipe 28. The cleaned 0r purified gaseous refrigerant passes from the top of the column I5 through the triple tube condenser l6 where it is liquefied. Some of the liquefied refrigerant flows back to the column through the reflux line 33 and the rest flows down the stand pipe 40 to the receiver 4| from which it is withdrawn through the valved discharge conduit 41. After passing through the utilization device or refrigerator 49, the refrigerant, now in gaseous state, flows through the conduit 50 to the compressor. inletulL, v.In cases where the liquid refrigerant is .used as a refrigerating and extracting medium for biological material, the absence of lubricatingoil will avoid contamination of the material. I

In some instances the jacketed cover 20 of the column may form a condenser, in which case condensate dripping from the interior walls of the cover will providesome or all of the reflux,

depending on the degree of cooling of thecover and on the flow through the reflux line 38. The latter flow can be adjusted in any suitable manner, as by manipulating a valve of the sight glass 35. The upper jacketed walls of the column may also form part of the condenser. When all the reflux is provided by dripping from the cooled upper end of the column, the flow through the reflux line is shut off, or this line may be omitted.

When certain refrigerants, such as dichlorodifluoromethane (Freon-12) are used, the superheat of the compressor is not always suflicient to drive the refrigerant completely out of the .oil at the bottom of the column. In such case, additional heat may be applied. When ethane is used in the system, it is desirable to refrigerate the column. For a system employing certain types of refrigerants it is necessary or desirable to jacket the condenser and other parts with a refrigerant.

During the operation of the system, the cleaning of the refrigerant proceeds continuously and the contaminants can be removed from the system without shutting down the system.

While the dome 20 at the upper end of the column I5 is shown to be jacketed, the jacketing may be omitted in cases where cooling of the dome is not required. I

The system of the invention can be used not only in treating biological material, but also in industrial processes in general, as in the manufacture of plastics and otherproducts.

What I claim as new and desire to secure by Letters Patent is:

1. In a refrigerating system including a refrigerant compressor and a refrigerant condenser, a refrigerant-scrubbing fractionator column connected between the compressor and the condenser and having an upflow passage for contaminant-bearing gaseous refrigerant, and. reflux means for returningapart of the liquefied refrigerant downwardly through the column from the upper portion "thereof to clean the gaseous refrigerant. v

2. In a refrigerating system including a. re-

frigerant compressor and a refrigerant condenser with an inlet and an outlet, a refrigerantcleaning fractionator column connected between said compressor and said condenser inlet and having an upflow passage for contaminant-bearing gaseous refrigerant, and a refrigerant-reflux connection from said condenser outlet to said column for refluxing a part of the liquefied refrigerant.

3. In a refrigerating system including a refrigerant compressor and a condenser, a refrigerantscrubbing column connected between the compressor and the condenser, said column having a jacket about its lower portion, the lower end of said jacket being connected to the compressor discharge, and said column having feed ports at a higher portion of said jacket communicating with the interior of said column.

4. In a refrigerating system including a refrigerant compressor and a condenser, a refrigerantscrubbing column connected between the compressor and the condenser, said column having a jacket about its lower portion, the lower end of said jacket being connected to the compressor discharge, and said column having feed ports at a higher portion of said jacket communicating with the interior of said column, the lower end of said column having an outlet permitting discharge of separated contaminants during operation of the system.

5. In a refrigerating system including a refrigerant compressor and a refrigerant condenser and a, liquid-refrigerant receiver, an upflow refrigerant-cleaning fractionator column connected between the compressor and the condenser, a liquid discharge connection from said condenser having two branches, a gravity-flow reflux conduit from one of said branches to the upper portion of said column for returning a part of the condensed refrigerant downwardly in said column, and a stand pipe connecting the other branch and said receiver.

6. In a refrigerating system including a refrigerant compressor and a refrigerant condenser and a liquid-refrigerant receiver, an upflow refrigerant-cleaning fractionator column connected between the compressor and the condenser, a liquid discharge connection from said condenser having two branches, a gravity-flow reflux conduit from one of said branches to the upper portion of said column for returning a part of the condensed refrigerant downwardly in said column, a stand pipe connecting the other branch and said receiver, and an overflow conduit from said discharge connection to said stand pipe.

7. A refrigerating system including a refrigerant compressor and a refrigerant condenser and having a refrigerant-scrubbing packed column forming a fractionator and connected between said compressor and condenser, said column having an upflow passage for gaseous refrigerant, and refluxing means for returning a portion of the condensed refrigerant downwardly in the upper portion of said column.

8. A refrigerating system including a, refrigerant compressor and a refrigerant condenser and having an upflow scrubbing fractionator column connected between the compressor and the condenser for removing oil from the refrigerant, said column having a feed for compressed gaseous, oilbearing refrigerant above the lower end thereof and having a bottom oil outlet permitting discharge of separated oil, heating means for the lower portion of said column below said feed, an oil receiver connected to said outlet, and refluxing means for returning a portion of the condensed refrigerant downwardly in the upper portion of said column.

9. In a refrigerating system, a refrigerantscrubbing column having an upflow passage for contaminant-bearing gaseous refrigerant, a refrigerant compressor having a, discharge connection with the lower portion of said column, a condenser having condensing surfaces in the upper portion of said column for producing a reflux of condensed refrigerant downwardly in said column to remove the contaminant from the refrigerant, and a discharge conduit for the cleaned gaseous refrigerant extending from the upper portion of said column, the lower end of said column having a contaminant-discharging outlet.

FRANCIS MARION POTTENGER, JR.

REFERENCES CITED The following references are of record in the file of this :patent:

UNITED STATES PATENTS Number Name Date 320,307 Suckert June 16, 1885 1,280,765 Kramer Oct. 8, 1918 1,617,631 Gay Feb. 15, 1927 2,149,358 Miller Mar. 7, 1939 2,190,138 Smith et a1 Feb. 13, 1940 2,230,219 Carey Feb. 4, 1941

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