US1938036A - Means for removing liquid mixtures from pressure vessels - Google Patents

Description

Dec. 5, 1933 Tic. MARTIN ET AL MEANS FOR REMOVING LIQUID MIXTURES FROM PRESSURE VESSELS Filed March 25, 1932 INVENTOR S2 BY ATTOR N EYS Patented Dec. 5, 1933 UNITED STATES PATENT OFFICE MEANS FOR REMOVING LIQUID MIXTURES FROM PRESSURE VESSELS New York 7 Application March 25, 1932. Serial No. 601,283

20 Claims.

The invention is a device for the removal of a substantially uniform proportion of a mixture of fluids having widely different vapor pressures and liquid and gas phases from a container in which the mixture is confined under pressure.

An example of such a mixture is one which contains carbon dioxide and ethylene oxide in the approximate proportion of nine parts of the former to one part of the latter. This material 10 is handled in conventional high pressure tanks or cylinders such as those used for the transportation of oxygen and, under normal conditions, the cylinders are approximately half full of the liquid phase of the mixture which is under about six hundred pounds pressure. Due to the widely different vapor pressures or tensions of the two components the vapor phase is largely carbon dioxide while the liquid phase is a mixture of the two having a higher ethylene oxide content than the average of the entire content of the cylinder.

The mixture under discussion is used as a fumigant and under some conditions one cylinder may be used for several fumigations. To be most effective, the proportion of the mixture used for 5 each fumigation should be substantially that of the entire content of the cylinder. Therefore, one of the objects of this invention is to provide a device that will remove this mixture from the cylinder in which it is contained in a substantially uniform proportion. Other aims, objects and novel features will be apparent from the following description and the accompanying illustration which is alongitudinal section through a cylinder having a valve and an eduction tube attached thereto. P

The objects of this invention are attained by attaching an eduction tube to the bottom of a valve employed to close a pressure vessel such as a cylinder adapted to contain the above mentioned fumigating mixture and providing this tube with suitable openings. These openings may be one or more in number according to the accuracy of the proportion of the mixture which is desired. In practice a suiliciently accurate proportion has been attained by providing this tube with three openings. The combined area of these.

openings should be less than the area of the cylinder outlet through the valve and best results have been obtained when the area of these openings is substantially 75% of that of the valve outlet, and the area of the opening or bore in the eduction tube is greater than that of the cylinder or valve outlet. The purpose of keeping the area of the inlet openings to the eduction tube below that of the outlet of the eduction tube or valve is to secure an appreciable pressure drop between the interior of cylinder and the interior of the eduction tube and thereby reduce to a negligible extent the undesirable eiiect of the static column of liquid in the eduction tube. I

With this device best results have been obtained when one inlet opening to the eductor tube is near the top of the tube in the gas phase of the mixture; when another opening is near the center of the lower half near the middle, of the liquid phase of the mixture, and the third opening is as near the bottom of the eduction tube or cylinder as is practical. This arrangement of openings tends to compensate for the increasing concentration of ethylene oxide in the liquid phase on account of evaporation of a portion of the carbon dioxide to supply the increasing proportion of the cylinder volume devoted to the gas phase. 7

At the beginning of Y the process of drawing this mixture from a cylinder the gas phase of the mixture is ejected through one opening in the educator tube and the liquid phaseof the mixture is ejected through two openings in this tube. Later when the surface of the liquid phase has dropped below the central orifice, a change in the proportion of the liquid and gas phases occurs and gas is ejected through two openings and liquid through one. This condition continues until the surface of the liquid phase has dropped below the lower opening. From then on gas phase only is ejected. By this arrangement it has been found that the proportion of carbon dioxide and ethylene oxide in the mixture drawn from a cylinder remains substantially uniform until the cylinder is practically exhausted and therefore regardless of whether the cylinder is entirely emptied or only a small portion iswithdrawn this proportion is maintained. In order to attain this result, however, the cylinder valve should always be fully open while the cylinder is being emptied.

The particular embodiment of the invention. shown in the drawing comprises a cylinder valve 10 of the type usually employed in a cylinder 19 adapted to contain oxygen. Extending down ward from the portion 11 of the valve 10, normally threaded into the top 20 of the cylinder, is a hollow copper eductor tube 12 extending substantially to the bottom 21 of the cylinder and having the lower end thereof closed by means of a plug 13 brazed or soldered therein. The

eductor tube 12.. is provided with anopening or orifice 14 about 2 inches below the bottom of the valve 10. A second opening 15 is provided .in the side of the eductor tube 12 from '5 to"8 inches above the bottom, and a third opening 16 is provided as near the bottom as practical.

The openings 14, 15 and 16 are each .078 inch in diameter and the combined areaof these three openings is substantially of the cross sectional area of either outlet opening 17 or 18 of the valve 10, which is less than the cross sectional area of the interior of the eduction tube.

The tube 12 is secured to the lower end of the valve 10 by means of brazing or soldering but other means may be used 3 as long as a tight joint is secured between the tube and the valve. Also one or more openings may be employed in the eductor tube and the distance between the openings and their position with respect to the cylinder may be varied without departing from the spirit of the invention or the scope of the claims.

We claim:

1. Means for the eduction of a uniform proportion of a mixture of fluids having liquid and gas phases and widely different vapor pressures from a cylinder in which the mixture is confined under pressure, comprising; an eduction tube attached to the outlet of said cylinder and extending substantially to the bottom thereof; said eduction tube having three openings in the wall thereof; one of said openings being near the top of said tube in the gas phase of said mixture; one of said openings being substantially at the center of the lower half of said tube in the liquid phase of'said mixture and the other of said openings being substantially at the bottom of said cylinder; the area of the inside of said eduction tube being greater than that of the outlet of said cylinder, and the combined area of the three openings in said eduction tube being substantially 75% of the area of the outlet .of said cylinder.

2. Means for the eduction of a uniform proportion of a mixture of fluids having liquid and gas phases and widely different vapor pressures from a cylinder in which the mixture is confined under pressure, comprising; an eduction tube attached to the outlet of said cylinder and having an interior area greater than said outlet; and a plurality of openings in the wall of said eduction tube; one of said openings being near the top of said tube in; the gas phase. of said mixture.

3. Means for-the eduction 'of a uniform-proportion of a mixture of fluids having liquid and gas phases and widely different vapor pressures from a cylinder in which the mixture is confined under pressure, comprising; an eduction tube attached to the outlet of said cylinderand extending substantially to the bottom thereof; a plu- 'rality of openings in the .wall of said eduction tube; the number of said openings in the liquid phase of said mixture being twice the number in the gas phase of said mixture when said cylinder is fully charged.

4. Means for the eductionof a uniformproportion of a mixture of fluids having liquid and gas phases and widely different vapor pressures from a cylinder in which the mixture is confined under pressure, comprising; an eduction tube attached to the outlet of said cylinder and extendingsubstantially to the bottom thereof; a plurality of openings in the wall of said eduction tube; the number ofsaid openings in the liquid phase of said mixture being greater than the number in the gas phase of said mixture when said cylinder is fully charged.

5. Means for the eduction of au'nifoim proportion of a mixture of fluids having liquid nd Gas phases and widely different vapor pressures from a cylinder in which the mixture is confined under pressure, comprising; an eduction tube attached to the outlet of said cylinder and extending substantially to the bottom thereof; a plurality of spaced openings in the wall of said eduction tube; the area of said openings being less than the area of the outlet of said cylinder.

6. Means for the eduction of a uniform proportion of a mixture of fluids having liquid and gas phases and widely different vapor pressures from a cylinder in which the mixture is confined under pressure, comprising; an eduction tube extend- .ing from the outlet of said cylinder substantially widely different vapor pressures and gas and liquid phases; a valve attached to the top of said cylinder and having an outlet opening therethrough; an eduction tube attached to said valve and extending substantially to the bottom of said cylinder; an opening in the wall of said eduction tube near the top to the gas phase of said mixture; an opening in the wall of said eduction tube substantially in the center of the lower half to the liquid phase of said mixture when said cylinder is fully charged; and an opening in the wall of said eduction tube at substantially the bottom thereof; the interior area of said eduction tube being greater than the outlet area of said valve; and a combined area of the openings in the wall of said eduction tube being substantially 75% that of the outlet opening in said valve.

8. In combination, a cylinder adapted to con tain" mixture of fluids having widely different vapo --,pressures and gas and liquid phases; a valve having an outlet therethrough for said cylinder; an eduction tube attached to said valve in said cylinder and extending substantially to the bottom thereof; a plurality of openings in the wall of said eduction tube; the number of said openings in the liquid phase of said mixture being twice that in thegas phase of said mixture when said cylinder is fully charged.

9. In combination, a cylinder adapted to contain a mixture of fluids having widely different vapor pressures and gas and liquid phases; a valve having an outlet therethrough for said cylinder;

an eduction tube attached to said valve in said j cylinder and extending substantially to'the bottom thereof; a plurality of openings in the wall of said eduction tube; the number of said openings'in the liquid phase of said mixture being greaterthan the number in the gas phase of said mixture when said cylinder is fully charged.

10. In combination, a cylinder adapted to contain a mixture of fluids having widely different vapor pressures and gas and liquid phases; a valve having an outlet therethrough for said cylinder; an eduction tube attached to said valve in'said cylinder and extending substantially to the bottom thereof; a plurality of openings in the wall of said eduction tube; the interior area of said eduction tube being greater than the area of the outlet opening in said valve; and the combined area of the openings in the wall of said eduction tube being less than the area of the outlet opening in said valve.

11. The combination with a container for a mixture of fluids having widely different vapor pressures and gas and liquid phases under pressure, of means whereby a mixture of substantially uniform proportions may be delivered from said container from the time it is substantially full until it is substantially empty.

12. In a cylinder adapted to contain a mixture of fluids having gas and liquid phases and widely different vapor tensions under pressure; means for removing said mixture in substantially uniform propostion comprising a valve in said cylinder having an outlet therefor; a tube having an interior area greater than said outlet extending therefrom substantially to the bottom of said cylinder, and a pluraliy of openings in the wall of said tube having a combined area less than the area of said outlet.

13. In a cylinder adapted to contain a mixture of fluids having gas and liquid phases and widely different vapor tensions under pressure; means for removing said mixture in substantially uniform proportion comprising a valve in the top of said cylinder having an outlet therefor; an eduction tube extending from said outlet substantially to the bottom of said cylinder, and three openings of uniform size in the wall of said tube, one near the top, one near the bottom, and one near the center of the lower half.

14. In a cylinder adapted to contain a mixture of fluids having gas and liquid phases and widely different vapor tensions under pressure; a combination of means for removing said mixture comprising a closable outlet and an eduction tube having a bore and a plurality of inlet openings; means for maintaining a substantially uniform proportion in the mixture removed comprising the position of said openings with respect to said cylinder, and the relative area of said outlet, said bore, and said openings; and means for reducing the effect of the static column of liquid in said tube comprising the relative area of said outlet and said inlet.

15. In a cylinder adapted to contain a mixture of fluids having gas and liquid phases of substantially equal volume and widely different vapor tensions under "pressure; means for removing said mixture in substantially uniform proportion comprising a closable outlet for said cylinder; an eduction tube connected with said outlet and extending substantially through both phases of said mixture; said eduction tube having an inlet opening in the gas phase of said mixture, an opening near the bottom of the liquid phase of said mixture, and an opening that is changed from the liquid phase to the gas phase of said mixture when substantially half of the liquid phase has been removed.

16. In a cylinder adapted to contain a mixture of fluids having gas and liquid phases under pressure; means for removing said mixture in substantially uniform proportion, comprising a closable outlet for said cylinder and an eduction tube having a bore larger than said outlet connected with the interior end thereof and extending downward into said mixture; the wall of said tube having a plurality of spaced inlet openings having a combined area substantially of the area of said outlet.

17. In a cylinder adapted to contain a mixture of fluids having gas and liquid phases and different vapor tensions under pressure; the combination of means for removing said fluids in substantially uniform proportion comprising a closable outlet for said cylinder above said mixture; an-eduction tube extending downward in said cylinder from said outlet substantially to the bottom. of said cylinder; and a plurality of vertically spaced openings in the wall of said tube; and means for producing a reduction in pressure between the interior of said cylinder and the interior of said tube during removal of said mixture'to reduce the effect of the static column of liquid in said tube.

18. In a cylinder adapted to contain a mixture of fluids having gas and liquid phases of substantially equal volume and widely different vapor tensions under pressure; a combination of means for removing said mixture comprising a closable outlet and an eduction tube; means for reducing the eifect of the static column of liquid in said tube during removal of said mixture comprising means for maintaining a pressure in said tube substantially lower than that in said cylinder; and means for maintaining a substantially uniform proportion in the mixture removed comprising means for increasing the proportion of the gas phase of said mixture during removal.

19. In a cylinder adapted to contain a mixture of fluids having gas and liquid phases under pressure; the combination of means comprising an eduction tube for removing said mixture; means for maintaining a substantially uniform proportion in the mixture removed comprising, means for maintaining a pressure in said tube substantially below that in said cylinder, and means for increasing the proportion of the gas phase of said mixture during removal.

20. In a cylinder adapted to contain a mixture of fluids having liquid and gas phases and widely different vapor tensions under pressure;

means for removing said mixture in substantialliquid phase when approximately half or more of said liquid phase has been removed.

THOMAS C. MARTIN. SIMON MEYER.

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