US3195557A - Float actuated gas vent - Google Patents

Description

y 20, 1965 L. w. YOUNG ETAL 3,195,557

FLOAT AG'IUATED GAS VENT Filed April 25, 1963 ELECT. SUPPLY SOURCE INVENTORS Zawrewce W )wng' Passe V. Me/ocfie A T TORNE YS United States Patent Delaware Filed Apr. 25, 1963, Ser. No. 275,546 2 Claims. (Cl. 137-202) This invention relates to separators and more particularly to an apparatus for separating two phases of a cryogenic medium (i.e. liquid and gas).

The use of cryogenic liquids in industrial applications has become increasingly more prevalent. In this connection, cryogenic liquids are being employed in a number of diverse industrial applications, for example, as a refrigerating means in deflashing and trimming apparatus for molded parts. In such applications it is extremely important both from the standpoint of economy and efliciency that the cryogenic medium be utilized in aliquid state. Inasmuch as some vaporization of the cryogenic liquid occurs during passage through the system supplying same notwithstanding the type or degree of insulation employed therein, the need exists for an effective apparatus which can be utilized to separate cryogenic vapor from the cryogenic liquid being supplied. To be effective, such. a separator should provide a continuous supply of cryogenic liquid at the point of utilization while at the same time salvaging the cryogenic vapor for reliquification. Moreover, the separating apparatus should be capable of effecting separation of the two phases of the cryogenic liquid rapidly and without causing additional loss of cryogenic liquid as a result of the separation process.

Accordingly, it is the prime object of the present invention to provide an improved apparatus for effecting the separation of two phases of a cryogenic medium.

Still another object of the present invention resides in the provision of a separation apparatus for a cryogenic medium which carries out the separation of the vapor state from the liquid state in a rapid and efficient manner without causing additional loss of the cryogenic liquid.

A further object of the present invention is to provide a separation apparatus for a cryogenic medium which is relatively inexpensive both in construction and operation.

Other objects and advantages of the present invention will become apparent from the, following detailed description when considered in conjunction with the accompanying drawing wherein the single figure is a simplified elevational view of a preferred embodiment of the separation apparatus with portions of the apparatus confining enclosure broken away.

In general, a preferred embodiment of the separation apparatus of the present invention includes a suitably insulated separation chamber whereto the cryogenic medium is supplied and wherein the cryogenic liquid is separated from the cryogenic vapor. A suitable float, which is supportable by the cryogenic liquid but not so by the cryogenic vapor, is positioned within the separation chamber. The float has a piston rod or shaft secured thereto which extends from the separation chamber to a region which houses a responsive switch means. As the height of the float varies in response to variations in the level of the cryogenic liquid within the separation chamber, a switch actuating piston member secured to the piston rod is advanced relative to the responsive switch means. When a substantial amount of cryogenic vapor accumulates in the separation chamber as indicated by the position of the float, the responsive switch means is actuated, thereby causing the opening of a vent valve that is connected to a vapor outlet for the separation chamber.

When opened, the vent valve allows the cryogenic vapor to be discharged from the chamber. Thereafter, as a suitable volume of cryogenic liquid is again accumulated within the chamber, the float is raised resulting in the closure of the vent valve. The Vent valve is sized so that a relatively rapid discharge of the accumulated vapor is achieved and a continuous supply of pure cryogenic liquid is realized. Moreover, the vapor outlet is suitably shielded to preclude the discharge of cryogenic liquid therethrough as vapor is being vented from the chamber.

Referring specifically to the drawing, a preferred embodiment of a gas separator in accordance with the present invention includes a separation chamber 11 that is defined by a cylindrical housing 12, which is preferably formed of a material such as stainless steel. The cylindrical housing 12 is confined within a rectangular enclosure 13 formed of a material such as aluminum. More particularly, the cylindrical housing, which defines the separation chamber 11 is positioned in spaced relation to the inner walls of the enclosure 13 and a suitable layer 15 of thermal insulation is provided in the region therebetween. Preferably, this insulation is polyurethane which is foamed in the region between the housing 11 and the enclosure 13 subsequent to the mounting of the housing therein although other forms of insulation can also be employed.

The separation chamber defining housing 12 is provided with a liquid inlet port 14, a liquid outlet port 16 and a vapor outlet port 17. Each of these ports communicate with suitable coupling members exteriorly of the enclosure 13 through conduit members 18 that maintain the housing 12 in fixed relation within the enclosure. As shown, in the drawing, the liquid inlet port 14 is positioned in a plane above the liquid outlet port 16 and the vapor outlet port 17 is located near the uppermost region of the cylindrical housing.

In this connection, it is important that the liquid inlet port 14 be maintained above the liquid outlet port 16 so that any vapor entering the chamber throu h the port 14 does not pass directly to the outlet port. Moreover, it is important that the ports 14 and 17 be maintained in suitable spaced relation so that incoming liquid is precluded from being discharged from the vapor outlet port. To further preclude this discharge of liquid, the vapor outlet port 17 is shielded by a baflie member 19. In the illustrated embodiment of the invention, the bafiie member 19 is a closed end cylinder provided with a plurality of relatively small vapor discharge apertures 1% along the upper surface thereof and a single drain aperture 19b along the lower surface thereof, the function of which will be more fully hereinafter described.

A spherical float 21, which is preferably formed of stainless steel, is confined within the separation chamber 11. The float 21 is selected so that it is supported by cryogenic liquid which accumulates within the chamber .but not so by an accumulation of cryogenic vapor due to the relatively low density of the latter. A shaft or piston rod 22 is secured to the float 21 and extends vertically upwardly through a sealing and bearing member 23 that is confined within a conduit member 24. As shown, the lower end of the conduit member 24 is suitably secured to an apertured portion in the upper wall of the cylindrical housing 12 and extends outwardly through the thermal insulation 15, an aperture in the upper wall of the enclosure 13, and extends into a housing 26 for a selectively actuable switch 29.

More particularly, the conduit member 24 extends into and through the housing 26 and serves as a guide for a switch actuating piston member 27 that is secured to the upper extremity of the shaft or piston member 22. As shown, the piston member 27 is mounted within the conduit member 24 for limited movement therein and relative to the selectively actuable switch 29, which might be wardly and away from the switch in response to the low.

ering of the level of cryogenic-liquid within the separation chamber 11, the switch 29 is actuated thereby.

.In this connection, the switch 29, which is preferably adjustably-mounted on the conduit member 24, is. electrically connected to a solenoid'30 by conductors 31.

As shown,the conductors 31 extend from the housing 26 and are connected to'a suitable source 32 of electrical' lowering of the level of the cryogenic liquid, an energizing circuit for the solenoid is provided by the closure of the switch 29 resulting from this movementof the piston member relative thereto.

The actuated element of the solenoid 30 is mechanically connectedto a valve 34 that controls the passage of vapor from the separation chamber 11 through the vapor outlet 17 and the conduit 18 associated therewith. In this connection, the valve 34 is connected to the cone duit 18 so that a critically. sized orifice provided by the valve is either fully open or'completely closed in response to the action of the solenoid 30. i

Themanner in which the effective separation of cryo genic liquid and vapor is effected by the aforedescribed embodiment'will best be understood from a consideration of a typical operational period. In this connection, when utilized in an industrial application requiring pure cryogenic liquid, the separator is preferably. located at the highest point in the system employing same; The

liquid inlet port 14 is connected through the coupling member 20 to a suitably insulated inlet line that supplies cryogenic liquid from a suitable-storage'or containment vessel (not shown) through the separator to the point of utilization. Inasmuch as some vaporization accompanies this transferrence' of the cryogenic liquid, both liquid and vapor are introduced through the'inlet port 14;tothe chamber 11.

For purposes of the remaining portion of this description, it will be assumed that .a suitable amount of cryogenic liquid has accumulated Within the chamber 11 so that the float 21 is in the position shown in the drawings. When the floati's so positioned, the vent valve 34 is closed, and .a continuous supply of cryogenic liquid is discharged through the liquid outlet port 16 and supplied to the apparatus associated With'theseparator.

If, for example, aportion of the liquid being supplied vaporizes during passage'through the inlet line, the vapor. introduced to thecha'm-ber rises to the liquid-vapor intere When the magnetic piston 27, which is connected to the float by the piston rod 22, is ultimately advancedout of proximity with the switch 29, the normally open contacts of the switch are closed and energizing current is sup; plied to the solenoid 30. 'When energized, the solenoid 3%) effects the opening'of the valve 34. Upon, opening,

the valve provides a discharge path for the vapor ac cumulatingin the separation chamber 11.

More particularly, when the valve 34, is open, vapor in the chamber. 11 passes through the apertures in the shielding cylinder19, the vapor outlet port 17, the conduit 78, the coupling member'ZO, and through the criti- 4 e 'cally sized orifice provided by the valve 34 to a suitable compressor-(not shown) associated with the separator.

In a conventional manner, the cryogenic vapor discharged from'the chamber is recompressed and returned to the 5 supply or containmentvcssel connected to the inlet line for the separator.

As the accumulated vapor is discharged, and cryogenic liquid again accumulates within the chamber, the float 21 and the piston member 27 remotely securedjthereto are advanced upwardly. That is, the disc'haige of vapor from the chamber 11' and the pressurerelief" incident thereto allows liquid to flowinto the chamber at a faster rate than liquid is discharged therefrom and the liquid level V is reestablished.v f Theresulting return movement of the 15 'magnetic'piston member 27 causes the switch 29 to be actuated and again openthe energizing circuit for the solenoid 30 When the solenoid 30 is deenergized, the valve 34 (i.e. the critically sized vent'orifice) is again fully closed. This aforedescribed intermittent venting of accumulated vapor continues as a continuous supply of cryogenic liquid'is being supplied from the source through v,the separator to the point of utilization.'

In this connection, it is important that the accumulated cryogenic vapor be vented-from the chamber at a suitaj ble' rate tov insure a continuous supply of pure cryogenic liquid at the outlet port 16. However, the vapor should not be discharged so rapidly thatviolent splashing of the liquid within the chamber'results', since such splashing leads to' the discharge of cryogenic liquid through the vapor outlet 17 and inhibits the efliciency, of the delivery and separation operations.

One example of separator operation clearly illustrates the results that can be achieved by employing theffeatures of the present invention fln this instance, cryogenic liquid was continuously supplied'through the inlet port 14 at a pressure of 20 p.s.i .g., and satisfactory and efiicient separation'was effected" by an orifice in the valve 34 which accommodatedthe venting of accumulating'vapor delivery pressure or adjusting the length of' the float chamber to provide more vapor space. In such cases, "the orifice, size is adjusted to conform to these variations.

' To further insure that cryogenic liquid is not lost through the vapor outlet port 17 during the venting process, 'the shielding, cylinder 19 is employed. While the vapor discharge apertures 1% provided therein readily accommodate;thepassage of vapor from the chamber 11, this member serves as a battle and effectively precludes liquid from being-discharged from the vaporoutlet port 17. However, shouldsome liquid pass into the cylinder,

I the drain aperture 19b in the lower surface thereof accommodates the discharge of this liquid back into the separation'chamber.

It should be vunderstood'thatthetoregoing is merely illustrative of the invention, and various equivalent structures can be devised without departing from the invention as set' forth in the'accompanying claims.

What is claimed is: i a v 1. Apparatus for effecting the separation of two phases of a cryogenic medium being supplied from a source thereofto a point of utilization; which apparatus comprises an insulated housing which idefinesa chamber for receiving'the cryogenic medium. positioned in elevated relation with respect to'both'said sourceand said point of utilization; said housing including an inlet port where through the medium'is supplied to the chamber, a liquid outlet port positioned belowthe inlet port, and a vapor 'outplet port positioned substantially above said inlet port; selectively energiz able means connected to said vapor outlet port'so as to' normally block the vapor discharge path providedthereby; switch means mountedon said insulated housing and electrically connected to said last mentioned means for controlling the energization thereof; a float member-confined within said housing, said float member at a rate of standard cubic feetper minute. Obvious:

13/, other venting rates can be obtained by varying the being supportable by cryogenic liquid but not supportable by cryogenic vapor; switch actuating means connected to said float member for movement therewith and relative to said switch means; said switch actuating means causing the actuation of said switch means in direct response to the lowering of the level of the cryogenic liquid within said chamber and the corresponding downward movement of said float member below a preselected level, said actuated switch means effecting the energization of said blocking means and the opening of said vapor discharge path; and a chamber defining spill over shield secured to the housing in surrounding relation to said vapor outlet port to preclude the spilling over of cryogenic liquid through said port as vapor is discharged, said shield having a series of orifices to accommodate the flow of vapor therethrough each of which orifice is of a cross sectional area which is substantially smaller than the cross sectional area of said vapor outlet port.

2. Apparatus for effecting the separation of two phases of a cryogenic medium being supplied from a source thereof to a point of utilization; which apparatus comprises an insulated housing which defines a chamber for receiving the cryogenic medium positioned in elevated relation with respect to both said source and said point of utilization; said housing including an inlet port wherethrough the medium is supplied to the chamber, a liquid outlet port positioned below the inlet port, and a vapor outlet port positioned substantially above said inlet port; selectively energizable means connected to said vapor outlet port and defining at least a portion of the vapor discharge path from said chamber, said last mentioned means including means normally blocking said vapor discharge path; switch means mounted on said insulated housing and electrically connected to said selectively energizable means for controlling the energization thereof and the opening of said discharge path; a float member confined within said housing, said float member being supportable by cryogenic liquid but not supportable by cryogenic vapor; switch actuating means connected to said float member for movement therewith and relative to said switch means, said switch actuating means causing the actuation of said switch means in direct response to the lowering of the level of the cryogenic liquid Within said chamber and the corresponding downward movement of said fioat member below a preselected level, said actuated switch means effecting the opening of said vapor discharge and maintaining said discharge path in an open condition during the actuation thereof; and an elongated tubular horizontally disposed spill over shield having one end closed and the other end secured in surrounding relation to said vapor outlet port to preclude the spilling over of cryogenic liquid through said port as vapor is discharged, said shield having an inner diameter lsightly larger than said vapor outlet port and being positioned so that the lowermost surface of the interior of said shield is in spaced relation to the bottom edge of said outlet port, said shield being provided with at least one orifice at the uppermost surface thereof to accommodate the flow of vapor therethrough, and further being provided with a drain orifice at the lowermost surface thereof so as to allow the draining of such cryogenic liquid as may spill over into said shield to prevent said liquid from entering said vapor outlet port.

References Cited by the Examiner UNITED STATES PATENTS 2,120,048 6/38 Turner 137412 2,367,851 1/45 Eaton 137412 XR 2,500,320 3/50 Pefi 137202 XR 2,848,879 8/58 Hesson 137202 XR WILLIAM F. ODEA, Primary Examiner.

ISADOR WEIL, Examiner.

Claims (1)

1. APPARATUS FOR EFFECTING THE SEPARATION OF TWO PHASES OF A CRYOGENIC MEDIUM BEING SUPPLIED FROM A SOURCE THEREOF TO A POINT OF UTILIZATION; WHICH APPARATUS COMPRISES AN INSULATED HOUSING WHICH DEFINES A CHAMBER FOR RECEIVING THE CRYOGENIC MEDIUM POSITIONED IN ELEVATED RELATION WITH RESPECT TO BOTH SAID SOURCE AND SAID POINT OF UTILIZATION; SAID HOUSING INCLUDING AN INLET PORT WHERETHROUGH THE MEDIUM IS SUPPLIED TO THE CHAMBER, A LIQUID OUTLET PORT POSITIONED BELOW THE INLET PORT, AND A VAPOR OUTLET PORT POSITIONED SUBSTANTIALLY ABOVE SAID INLET PORT; SELECTIVELY ENERGIZABLE MEANS CONNECTED TO SAID VAPOE OUTLET PORT SO AS TO NORMALLY BLOCK THE VAPOR DISCHARGE PATH PROVIDED THEREBY; SWITCH MEANS MOUNTED ON SAID INSULATED HOUSING AND ELECTRICALLY CONNECTED TO SAID LAST MENTIONED MEANS FOR CONTROLLING THE ENERGIZATION THEREOF; A FLOAT MEMBER CONFINED WITHIN SAID HOUSING, SAID FLOAT MEMBER BEING SUPPORTABLE BY CRYOGENIC LIQUID BUT NOT SUPPORTABLE BY CRYOGENIC VAPOR; SWITCH ACTUATING MEANS CONNECTED TO SAID FLOAT MEMBER FOR MOVEMENT THEREWITH AND RELATIVE TO SAID SWITCH MEANS; SAID SWITCH ACTUATING MEANS CAUSING THE ACTUATION OF SAID SWITCH MEANS IN DIRECT RESPONSE TO THE LOWERING OF THE LEVEL OF THE CRYOGENIC LIQUID WITHIN SAID CHAMBER AND THE CORRESPONDING DOWNWARD MOVEMENT OF SAID FLOAT MEMBER BELOW A PRESELECTED LEVEL, SAID ACTUATED SWITCH MEANS EFFECTING THE ENERGIZATION OF SAID BLOCKING MEANS AND THE OPENING OF SAID VAPOR DISCHARGE PATH; AND A CHAMBER DEFINING SPILL OVER SHIELD SECURED TO THE HOUSING IN SURROUNDING RELATION TO SAID VAPOR OUTLET PORT TO PRECLUDE THE SPILLING OVER OF CRYOGENIC LIQUID THROUGH SAID PORT AS VAPOR IS DISCHARGED, SAID SHIELD HAVING A SERIES OF ORIFICES TO ACCOMMODATE THE FLOW OF VAPOR THERETHROUGH EACH OF WHICH ORIFICE IS OF A CROSS SECTIONAL AREA WHICH IS SUBSTANTIALLY SMALLER THAN THE CROSS SECTIONAL AREA OF SAID VAPOR OUTLET PORT.

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