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Publication numberUS3837177 A
Publication typeGrant
Publication dateSep 24, 1974
Filing dateNov 1, 1973
Priority dateNov 1, 1973
Also published asCA1003233A1
Publication numberUS 3837177 A, US 3837177A, US-A-3837177, US3837177 A, US3837177A
InventorsE Bottum, F Rockwell
Original AssigneeRefrigeration Research
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Suction accumulator
US 3837177 A
Abstract
The suction accumulator of the invention is designed for use with the suction or compression side of a refrigeration system. The accumulator comprises a casing having an inlet and an outlet. An outlet tube structure is provided within the casing connected to an outlet from the casing. The outlet tube structure includes an outer tube and an inner tube of smaller diameter positioned therewithin. This structure extends from a point adjacent the bottom of the casing to the casing outlet and acts as a suction device to draw liquid from the casing and expel it into the casing outlet at a metered rate.
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United States Patent Rockwell et a1.

[ Sept. 24, 1974 1 SUCTION ACCUMULATOR Primary Examine'rMeyer Perlin [75] Inventors: Frank H. Rockwell; Edward W. g i Agent or Flrm*whlttemore Hulbert &

Bottum, both of Brighton, Mich. e nap [73] Assignee: Refrigeration Research, Inc.,

Brighton, Mich. [57] ABSTRACT The suction accumulator of the invention is designed [22] Flled 1973 for use with the suction or compression side of a re- [21] Appl. No.: 411,913 frigeration system. The accumulator comprises a casing having an inlet and an outlet. An outlet tube structure is provided within the casing connected to an out- C(11. let from the casing. The Outlet tube Structure includes [58] d 62/468 503 an outer tube and an inner tube of smaller diameter le 0 positioned therewithin. This structure extends from a point adjacent the bottom of the casing to the casing [56] References Clted outlet and acts as a suction device to draw liquid from UNITED STATES PATENTS the casing and expel it into the casing outlet at a me- 3,012,414 12/1961 La Porte 62/503 tered rate. 3,111,819 11/1963 Williams 62/503 4 Claims, 4 Drawing Figures I 36 I I l K I I Ix /5 I I 42 l a I I1- .I.L -gI R;

I I -36 I II I I II m I l I :1 I I |I 1 40 I 1 I II I I I I I i I II //0 l 1 I II I II //2 I :I I I I II I I I I I] I I I //4 I I H I I I I I Z6 I I I I I I I I I I i "22 I I I I I I *I :1 111i A? BACKGROUND OF THE INVENTION The suction accumulator to which the present invention pertains is particularly adapted for use in refrigeration systems such as air conditioning, heat pump, truck refrigeration and many other applications which require intermittent operation of the refrigeration compressor. The suction accumulator is provided between the evaporator and compressor of a refrigeration system. Vaporized refrigerant is received from the evaporator and passed on through the suction accumulator to the compressor.

During the off cycle of such systems, large quantities of liquid often return through the suction line and find their way into the compressor crankcase when a suction accumulator is not provided. This is especially true in remote applications where the suction line may trap or hold quantities of liquid which may suddenly be dumped into the compressor as the compressor starts up. This is frequently the cause of broken valves, pistons, broken or bent connecting rods, blown gaskets and bearing washout.

When a suction accumulator is used, liquids such as refrigerant and lubricating oil are collected in the accumulator and slowly metered to the compressor. The metering protects the compressor against undue shock resulting from large amounts of liquid being present in the compressor crankshaft being suddenly injected into the compressor from the suction line. The metering also prevents liquid refrigerant from forcing the oil out of the bearings causing bearing washout. Bearing washout results in the bearings and compressor motor burning out.

A number of patents have issued in the past directed to suction accumulators, for example, US. Pat. Nos.: 3,084,523, 3,212,289, 3,344,506, 3,420,071, 3,444,367, 3,563,053, 3,589,395, 3,609,990, 3,626,715, 3,643,465, 3,643,466, 3,012,414. Such prior constructions generally employ a U-tube which acts as a conduit for refrigerant gas to pass through the accumulator and on to the compressor. The U-tube is provided with a small metering opening which extends to the bottom of the accumulator casing. This opening acts as a metering opening to slowly draw liquid from the easing into the U-tube to thereby meter the amount of liquid which passes from the accumulator to the compressor. Other systems have been suggested wherein a single tube of small diameter is used as a metering device.

The present invention provides an improved version wherein a straight inner tube is provided within a straight outer tube. The outer tube is open at the top for the ingress of gaseous refrigerant thereinto. A small opening is provided in the bottom of the outer tube for metering of liquid thereinto. The gaseous refrigerant passes into the outer tube down to the bottom thereof and then up the inner tube which is connected to the compressor. Thus, essentially, a single elongated tubular device is provided within the accumulator casing.

The single tubular structure provides more space within the accumulator casing which permits use of other structure within the casing such, for example, as a heat exchange coil and also permits a single casing to be used with a wider range of tube sizes which is especially important in connection with the large tube size.

SUMMARY OF THE INVENTION A suction accumulator for a refrigeration system is provided. The accumulator includes a casing having a inlet and an outlet. An outlet tube structure is provided within that casing. This structure comprises an outer tube and an inner tube of smaller diameter positioned therewithin. The inner tube extends from the outlet towards the lower portion of the casing. The lower end of the inner tube is open. The outer tube has a closed lower end and extends over the inner tube towards the upper portion of the casing and terminates in an open end for the passage of gas through the outer tube and thence through the inner tube. The outer tube has an opening adjacent to the lower portion of the casing to draw liquid from the casing and expel it into the casing outlet at a metered rate.

IN THE DRAWINGS FIG. 1 is a side elevational view in section along line ll of FIG. 2 of one embodiment of the suction accumulator of the present invention;

FIG. 2 is a top plan view of the suction accumulator of FIG. 1;

FIG. 3 is a bottom view of an enlarged scale of the tubular structure provided within the casing of the suction accumulator of F IG. 1; and

FIG. 4 is a sectional view of the lower portion of the tubular structure taken substantially along the line 4--4 of FIG. 3.

DESCRIPTION OF A PREFERRED EMBODIMENT As illutrated in the Figures, the suction accumulator 10 includes a casing 12 which comprises an openended tube 14 having an upper end closure 16 and a lower end closure 18 secured thereto as by brazing. While the accumulator 10 is shown with the longitudinal axis vertically oriented, this axis may also be oriented horizontally with the inlets and outlets approximately re-arranged. Further, the inlets and outlets may enter the sides as well as through the top as shown in FIG. 1.

An outlet fitting 20 extends through the upper end closure 16 into the interior of the casing 12. An elongated inner tube 22 is attached at one end to the fitting 20. The tube 22 extends downwardly to a point adjacent the lower end closure 18. The lower end 24 of the tube 22 is open and is cut along a bias.

The inner tube 22 is received within an outer tube 26. The tube 22, 26 may be fabricated of, for example, steel. The diameter of the inner tube 22 is significantly less than the diameter of the outer tube 26. For example, in one embodiment, the inner tube 22 has a diameter of 1 V4 inches, while the outer tube 26 has a diameter of 2 inches. Thus there is considerable unoccupied space within the outer tube 26 permitting flow of gaseous material therethrough. The inner tube 22 is secured to and positioned against the inner surface of a wall portion of the outer tube 26 as by welding. The bias along which the lower end of the inner tube 22 is defined extends from the contacted wall surface of the outer tube 26 upwardly towards the oppositely disposed wall portion of the outer tube to increase the effective size of the opening into the inner tube 22.

A cap 28 is provided on the lower end of the outer tube 26. A recess 30 is formed centrally of the cap 28. A small metering opening 32, for example, an opening one-eighth inch in diameter, is formed centrally'of the recess 30. A screen 34 is spot welded over the recess 30 to act as a strainer for fluid passing through the opening 32 into the outer tube 26. The screen 34 may be, for example, 30 X 50 mesh and fabricated of monel metal. Another small opening 36 is provided adjacent the upper end of the inner tube 22 to equalize pressure within the tubes 22, 26.

An inlet tube 38 also extends through the upper end closure 16. The inlet tube 38 extends for a short distance into the casing. One wall portion 40 of the tube 38 is deformed inwardly into the tube 38 to form a scoop for directing the flow of incoming fluid into the casing.

In operation of the accumulator, cold refrigerant gas having a small amount of entrained liquid refrigerant therein enters the accumulator through the inlet tube 38. The incoming gases, which move at a relatively high velocity, are directed tangentially against the inner wall of the casing and generally follow a circular path around the casing interior. The gases are then free to expand, with resultant reduction of the velocity thereof. As a consequence, incoming gases are not directed as a high-speed jet against any liquid which may be retained in the lower portion of the casing. This prevents turbulence of the liquid which may result in objectionable foaming and also prevents splashing of liqaid.

The refrigerant gases which enter the casing are drawn into the upper open end 42 of the outer tube 26. Thesegases pass downwardly through the outer tube 26 and thence into the open lower end 24 of the inner tube 22. The gases are passed from the innter tube 22 through the outlet fitting 20 and thence to the compressor of the refrigeration system (not shown). The compressor, which creates a suction, draws the gaseous refrigerant through the accumulator at a relatively rapid rate.

Liquid refrigerant which enters the accumulator through the inlet tube 38 drops to the bottom of the accumulator and is subsequently drawn through the opening 32 and then through the inner tube 22 and out of the accumulator. It will be appreciated that the liquid which is metered into the inner tube 22 is entrained in the stream of gaseous refrigerant. It remains entrained in the gas as it passes from the accumulator and is drawn to the compressor of the system. The opening 32 acts as a restriction and causes liquid refrigerant to be metered into the compressor at a controlled rate. The accumulator thus acts to prevent large amounts of liquid refrigerant from suddenly entering the compressor. Such sudden surges ofliquid may result in seriously damaging the compressor.

During operation of the refrigeration system, there are times when an unusual amount of refrigerant will collect in the accumulator. For example, -when the system is shut off, such as in the case with an intermittently operated air conditioning system, the refrigerant tends to condense in the entire systemand collect in the accumulator. A similar situation may occur when the system is operated under low load conditions. The metering of the liquid refrigerant through the opening 32 results in liquid refrigerant being delivered to the compressor at a non-harmful rate.

What we claim as our invention is:

l. A suction accumulator for a refrigeration system comprising a casing, an inlet to the casing, an outlet from the casing, an outlet tube structure comprising an outer tube and an inner tube of smaller diameter positioned therewithin, said inner tube extending from the outlet towards the lower portion of the casing, the lower end of the inner tube being open, the outer tube having a closed lower end and extending over the'inner tube towards the upper portion of the casing and terminating in an open end for the passage of gas through the outer tube and thence through the inner tube and out of the outlet from the casing, said outer tube having an opening therein adjacent the lower portion of the casing to draw liquid from the casing and expel it into the casing outlet at a metered rate.

2. A suction accumulator as defined in claim 1, further characterized in that the lower open end of the inner tube is formed along a bias with respect to the longitudinal axis of the inner tube to thereby present a larger area for communication with the outer tube for free passage of gas from the outer tube through the inner tube.

3. A suction accumulator as defined in claim 2, further characterized in that the inner tube is positioned against the inner surface of a wall portion of the outer tube to thereby define a passageway in the outer tube around the inner tube, the bias along which the lower end of the inner tube is defined extending from the contacted wall surface of the outer tube upwardly towards the oppositely disposed wall portion of the outer tube.

4. A suction accumulator as defined in claim 1, further characterized in the formation of a recess in the lower end of the outer tube, said opening in the outer tube being formed in said recess, and a screen secured over the recess externally of the outer tube to strain foreign particles from liquid flowing-into the outer tube through said opening.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3012414 *May 9, 1960Dec 12, 1961Porte Francis L LaRefrigeration apparatus with liquid trapping means
US3111819 *Nov 3, 1961Nov 26, 1963Bell & Gossett CoEvaporator with oil return means
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4041728 *Jul 21, 1975Aug 16, 1977Tecumseh Products CompanySuction accumulator
US4182136 *Dec 22, 1977Jan 8, 1980Tecumseh Products CompanySuction accumulator
US4194370 *Feb 26, 1979Mar 25, 1980Tecumseh Products CompanyAccumulator for refrigeration system
US4199960 *Oct 26, 1978Apr 29, 1980Parker-Hannifin CorporationAccumulator for air conditioning systems
US4231230 *Apr 11, 1979Nov 4, 1980Carrier CorporationRefrigerant accumulator and method of manufacture thereof
US4236381 *Feb 23, 1979Dec 2, 1980Intertherm Inc.Suction-liquid heat exchanger having accumulator and receiver
US4458505 *Mar 25, 1983Jul 10, 1984Parker-Hannifin CorporationSuction line accumulator
US4488413 *Jan 17, 1983Dec 18, 1984Edward BottumSuction accumulator structure
US4528826 *Jun 28, 1984Jul 16, 1985Avery Jr Richard JRefrigerant accumulator and charging apparatus and method for vapor-compression refrigeration system
US4583377 *May 24, 1984Apr 22, 1986Thermo King CorporationRefrigerant suction accumulator, especially for transport refrigeration unit
US4627247 *Mar 21, 1986Dec 9, 1986Tecumseh Products CompanySuction accumulator
US4651540 *Mar 21, 1986Mar 24, 1987Tecumseh Products CompanySuction accumulator including an entrance baffle
US5075967 *Aug 3, 1990Dec 31, 1991Bottum Edward WMethod of assembing a suction accumulator
US5076066 *Oct 15, 1990Dec 31, 1991Bottum Edward WSuction accumulator and flood control system therefor
US5167128 *Oct 15, 1991Dec 1, 1992Bottum Edward WSuction accumulator and flood control system therefor
US5184479 *Dec 23, 1991Feb 9, 1993Ford Motor CompanyAccumulator for vehicle air conditioning system
US5184480 *Dec 23, 1991Feb 9, 1993Ford Motor CompanyAccumulator for vehicle air conditioning system
US5201792 *Dec 23, 1991Apr 13, 1993Ford Motor CompanyAccumulator for vehicle air conditioning system
US5570589 *Jan 27, 1995Nov 5, 1996Rheem Manufacturing CompanyRefrigerant circuit accumulator and associated fabrication methods
US5722146 *Apr 8, 1996Mar 3, 1998Refrigeration Research, Inc.Method of assembling a suction accumulator in a receiver for a heat exchanger
US5778697 *Mar 15, 1996Jul 14, 1998Parker-Hannifin CorporationAccumulator for refrigeration system
US6062039 *Dec 29, 1998May 16, 2000Parker-Hannifin CorporationUniversal accumulator for automobile air conditioning systems
EP0104750A2 *Aug 18, 1983Apr 4, 1984Richard John Avery, Jr.Refrigerant accumulator and charging apparatus and method for vapor-compression refrigeration system
EP0238742A1 *Jul 16, 1986Sep 30, 1987Tecumseh Products CompanySuction accumulator
EP0299947A1 *May 25, 1988Jan 18, 1989Karl SteinkellnerHeat pump
EP0349704A1 *Mar 7, 1989Jan 10, 1990Tecumseh Products CompanySuction accumulator with dirt trap
WO1989000666A1 *Jul 12, 1988Jan 26, 1989Karl SteinkellnerHeat pump
Classifications
U.S. Classification62/503
International ClassificationF25B43/00, F04B39/16
Cooperative ClassificationF25B2400/03, F25B2400/02, F25B43/006
European ClassificationF25B43/00C