US1747308A - Liquid sealing means for containers - Google Patents

Description

Feb. 18, 1930. E. J. LE VY 1,747,308

LIQUID SEALING MEANS FOR CONTAINERS FileC1 1926 2 Sheets-Sheet 1 Fig.1.

Fig 6 I N VEN TOR.

Edward J. Levy Feb. l8, 1930. E. J. LEVY LIQUID SEALING MEANS FOR CONTAINERS Filed Jan. 28, 1926 2 Sheets-Sheet 2 Z ATTORN s.

INVENTOR. Edward. J. Levy ME.= J

Patented Feb. 18, 1930 .UNlTED STATES EDWARD J. LEVY, F CLEVELAND, OHIG,

ASSIGNOB TO THE BISHOP & BABCOCK MANU- FACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO LIQUID SEALING MEANS FOR CONTAINERS Application filed January 28, 1926.

The present invention relates to liquid sealing means for containers, and more particularly to apparatus for use in conjunction with M high voltage transmission lines. In the transmission of current of high voltage in cities a conductor in the form of a wire is disposed within, and spaced from, a suitable conduit, such as a lead sheath, and between the sheath and wire is an insulation, such as 5 an insulating paper impregnated and embedded in petrolatum. Not only does the insulating substance become heated by the heat produced in the conductor, but also it is of course heated by reason of external temperatures, with the result that there is a daily temperature change in the insulating substance of a few degrees, and an annual change (between winter and summer) of a number of degrees. The result of these temperature so changes isot course an expansion of the fluid and means must be provided for taking care of this expansion and allowing the expanded fluid to flow into some sort of a suitable reser voir. It is also highly desirable in some cases to maintain some constant pressure on the insulating substance.

In the past, where a fluid pressure'has been desired, large reservoirs, consisting generally oi' expansible and collapsible diaphragms aamounted in suitable containers, and arranged to exert a pressure by gravity head where ground contour permitted, or mounted in towers to create such pressure by gravity ,head, have been connected to the lead conduit 33 at suitable intervals to receive the fluid which is forced into them upon increases of temperature, but these are both extremely expensive and require altogether too much space for onvenience. A second form of apparatus which has been employed in the past where anything more than a nominal fluid pressure in the cable was not essential,consists in sealed containers having expansible and collapsible diaphragms or metallic bellows, this form of device being inserted at frequent intervals in the sheath. The present invention relates to an improved apparatus for providing for the expansion of the insulating compound in such conductor where either no pressure,

59 nominal or substantial pressures are required,

Serial No. 84,424.

and is particularly designed to be simple and inexpensive in its construction and convenient in size. To the accomplishment of the foregoing and related ends, said invention, then, consists or" the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings z- Fig. '1 is a side elevation, largely diagrammatic in character, illustrating the disposition of the present apparatus in connection with electrical conductors in a subterranean conduit; Fig. 2 is a side elevation of the conductors in such conduit; Fig. 3 is a transverse vertical section through my improved apparatus; Fig. l is a similar View of the apparatus in a difi'erent operative position; and Figs. 5 and 6 are similar views of modifications or" the invention.

It should be further noted that air must be rigidly excluded from the entire circuit of which the present apparatus is a part, and it is therefore essential that the container be both an expansible one, so that it may be always tilled' with the insulating fluid, and yet be hermetically sealed from the atmosphere.

In Fig. 1 I have shown a subterranean conduit 1 in which are disposed one or more conduits 2. These conduits, which are'hollow, are connected by conduits 3 to the expansible chamber 4, which is disposed in a manhole 5 to which access may be had from the street level. The connecting conduits8 are usually connected to cable conduits 2 at joints 6 in the latter, as shown in Fig. 2. V

In Fig. 8 I have shown a transmission conduit 2, within which is mounted an electrical conductor 7, while between the conduit and conductor is an insulating substance, such as paper and petrolatum 8. At suitable intervals the sheath 2 is connected with the conduits 3, which communicate with the container lmounted upon any suitable supports 11 and closed at its base, except for the opening 3. Disposed within the container is a second container 12 which is open at its bottom, but has an imperforate top 13. The container 4 has an inwardly extending flange 14 and a downwardly extending flange 15, which is parallel with the side walls of the container. The inner container 12 has an outwardly ex tending flange 16 and an upwardly extending flange 17 the latter being parallel with the side wall 12 of the container, and the flanges 15 and 17 interlocking as indicated in Fig. 3, to form a labyrinthian seal, in which may be disposed any sealing liquid, such as mercury 18. The method of assembly of the two containers in the arrangement shown may be any convenient method, such for example as the positioning of the container 12 within the container 4 and the subsequent joining of the flange 15, which is integral with the flange 14, to the upper edge of the side walls 4 of the first container, by welding or any other suitable method.

Extending outwardly from the upper edge 20 of the container 12 are arms 21, to which are connected tension springs 22 connected at their other end to the outer and lower container, these springs serving to maintain an approximately constant downward pressure on the upper container throughout the relative movement of the two containers. In this way a constant resistance to expansion is provided and the apparatus is always maintained at a minimum height, the upper container rising only upon a flowof the insulating compound into the space between the two containers when the change in temperature, creating further expansion, is suflicient to overcome, first, the Weight of the upper container, and, second, the spring pressure ex-' erted by the springs 15. Obviously, other means than springs, such as weights, for instance, may be used to create the pressure, or, under certain conditions, no additional resistance to movement may be needed.

\Vhen the apparatus is initially assembled and in communication with the cable conduit it is of course necessary to fill the space between the two telescoping containers with the insulating compound completely in order to exclude air, and this may be done in any suitable manner, which it is unnecessary to describe in detail. Nor is it thought necessary to describe methods for venting the trapped air in the containers, as suitable vents for this purpose mayof course be provided and subsequently sealed;

When the apparatus is thus assembled and is in operation the space between the two containers is filled with the insulating compound 8, vwhich also extends upward between wall 4 and flange l7 and then downwardly between the flange 15 and the flange 17 where it rests upon the top of the mercury column 18. The mercury will of course be forced downwardly in the outer chamber and upwardly in the inner chamber until there is a suificient head on the mercury to balance the pressure exerted by the insulating compound. Upon the flow of additional fluid into the space between the two containers the pressure in this space increases slightly and lifts the upper container, thus producing additional volume in the space between the two containers, while maintaining the seal between the insulating substance and the atmosphere through the mercury 18 and at the predetermined approximate pressure. Upon a lowering of the temperature of the insulating compound its volume is reduced and it will flow back into the sheath 2 through the communicating conduit 3. The springs 22 and the weight of the upper cylinder will assist in forcing the compound to return to the sheath, and it should be understood that the space between the containers is initially filled with the insulating compound so that there is no air at any point in contact with the compound.

Any suitable guide means may be provided for maintaining the two containers in parallelism during their movement and I have here illustrated a series of projecting studs 25 on the wall 17, these studs contacting with the inner surface of the wall. 4 and serving to maintain the desired relationship between the containers.

One of the advantages of the present sealing means is of course the mounting of the sealing chamber on the movable container, that is, the sealing chamber, consisting of the space between the walls 12 and 17, is carried with this container and the seal is thereby lifted as the container lifts instead of the container moving out of the seal, as is the case with containers which are merely set into liquid filled chambers where the liquid remains in the lower or fixed chamber during the movement of the upper chamber. The result of this construction is that the height of the sealing chamber, or rather of the column of sealing liquid, may be very much reduced for any given range of movement.

In Fig. 5 are shown two containers 40 and 41 each of which is provided with one open end while the containers are disposed telescopically as in the form previously described. The upper or movable container 40 extends into a sealing chamber 42 formed between the wall proper 41 of the lower container and a second wall 43. A sealing liquid is disposed within the chamber 42, the chamber being filled to a point which is sufficient to maintain the lower edge of the container 40.always below the surface of the sealing liquid even in the uppermost position of the movable container and with sufficient heat on the sealing liquid to balance the internal pressure exerted by the liquid which is confined between the two containers.

In this form of apparatus in which the sealing liquid'is not carried on a chamber formed as a part of a movable container with the result that there is a constantly varying head on the sealing liquid, the apparatus is practical only with certain few liquids which must have very definite characteristics as regards their specific gravity and the property of remaining liquid at temperatures which are far below the boiling point of the liquid confined between the two containers. Because of limitations upon the size of the apparatus in most commercial installations, both as regards to height and diameter, where used in subterranean conduits in connection with electrical conductors, it is necessary that the sealing liquid have a specific gravity of not less than several times the specific gravity of the confined liquid and the effectiveness and economy of the apparatus vary directly with any further increase of the specific gravity of the sealing liquid. Various liquids may be used, such, for example as mercury and certain low melting point alloys, principally combinations of lead, bismuth, tin and other metals which have melting points ranging from 150 to 300 F., and specific gravities which are a number of times the specific gravity of the confined liquid. It is also necessary, of course, that a sealing liquid be chemically inert to the confined liquid and this is true as regards petrolatum as a confined liquid and the sealing substance mentioned above. It will be readily understood that, if the normal temperature of a container be below the melting point of the sealing substance, then heat may be suppliedv in any suitable manner to maintain the temperature of the container, or at least of the sealing substance at a point which is suificient to keep the sealing substance in a liquid condition.

In Fig. 6 I have shown substantially the apparatus illustrated in Fig. 5 and consisting of two telescopically mounted containers and 52, the lower container 50 having an interior wall or flange 51 which forms a sealing chamber which dips the downwardly extending wall of the upper container 52. Under certain conditions it may be desirable to reduce either the overall height ofthe apparatus or the weight and quantity of sealing liquid, and in this case an artificial head may be created with sealed liquid 55 contained in the sealing chamber by means of an annular piston 53 provided with a weighted portion 54. This means of maintaining a head can be used to particular advantage with such liquids as mercury, which are easily confined and which do not flow readily through small openings or orifices, such for example as through the space between the piston 53 and the two spaced container walls 50 and 52. Resilient or other equivalent means may obviously be substituted for the weights to secure the pressure against the sealing column which is desired.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention 1. In apparatus of the character described, the combination of a vertically disposed container open at its top, a second container mounted within said first-named container and open at its bottom, a conduit containing a fluid communicating with the interior of said two containers, and said containers having interlocking flanges, the space between said flanges containing a liquid forming a sealing means for said containers.

2. In apparatus of the character described, the combination of a vertically disposed container open at its top, a second container open at its bottom, said containers being telescopically mounted, and a conduit containing a fluid communicating with the interior of said two containers, said containers having interlocking flanges and the space between said flanges containing a sealing liquid.

3. In apparatus of the character described, the combination of a vertically disposed container open at its top, a second container open at its bottom, said containers being telescopically mounted, a conduit containing a fluid communicating with the interior of said two containers, said containers having interlocking flanges and the space between said flanges containing a sealing liquid, and means exerting the constantly acting pressure tending to telescope said two containers.

4. In apparatus of the character described, the combination of a vertically disposed c011- tainer open at its top, a second container open at its bottom, said containers being tel scopically mounted, a conduit containing a fluid communicating with theinterior of said two containers, said containers having interlocking flanges and the space between said flanges containing a sealing liquid, and means for limiting the relative movement between said containers.

5. In apparatus of the character described, the combination of a vertically disposed container open at its top, a second container open at its bottom, said containers being telescopically mounted, a conduit containing a fluid communicating with the interior of said two containers, said containers having interlocking flanges and the space between said flanges containing a sealing liquid, and means on said flanges for limiting the relative movement between said containers. 1

6. In apparatus of the character described, the combination of two vertically disposed containers each having one open end, said containers being of very slightly difl'erentdiameter s and being disposed telescopically to enclose a predetermined space, liquid sealing means carried on said containers, said means including interlocking. flanges and one of said flanges forming with its associated container a chamber surrounding the upper of said two containers, and a sealing liquid carried in said chamber and supported by said upper container.

7. In apparatus of the character described, the combination of two vertically disposed containers each having one open end, said containers being of very slightly different diameters and being disposed telescopically to enclose a predetermined space, liquid sealing means carried on said containers, said means including an open chamber formed.

about one wall of the upper of said two containers, a liquid contained in said chamber,

and a flange extending from the other of said containers into such chamber below the level of the liquid therein.

8. In apparatus of the character described, the combination of two vertically disposed containers each having one open end, said containers being of very slightly different diameters and being disposed telescopically to enclose a predetermined space, liquid sealing means carried on said containers, said means including an open chamberformed about one wall ofthe upper of said two containers, a liquid contained in said chamber, and a flange extending from the other of said containers into such chamber below the level of the liquid therein, and said flange also serving to limit the relative movement between said containers.

9. Liquid sealing means comprising two adjacently disposed relatively movable walls, an angular chamber forming flange disposed on one of said walls, a second angular flange extending from the other of said two walls and into the chamber formed by said firstnamed flange, and a liquid contained in said chamber and extending above the edge of said second named flange.

10. Liquid sealing means comprising two vertically disposed relatively movable walls, one of said walls carrying therewith a fixed angular flange constituting an opensealing chamber and the other of said walls having an inverted flange extending into the chamber formed by said first-named flange.

11. Liquid sealing means comprising two pairs of adjacentlydisposed relatively movable walls, an angular chamber forming flange disposed on one or" said walls, the second of said two walls extending into such chamber formed by said flange and a liquid contained in said chamber and extending above the edge of said second wall.

12. In apparatus of the character described, the combination of two pairs of vertically disposed telescopically mounted containers, a conduit containing a fluid communicating with the interior of said two containers, an angular chamber forming flange disposed on one of said containers and the other of said two containers extending into such chamber formed by said flange, and a sealing liquid contained in said flange and extending above the edge of said second container.

13. In sealing apparatus, the combination of two relatively movable walls, one of said walls confining a liquid under pressure, sealing means interposed between said walls, and acting to balance the pressure of the confined liquid, said means including a substance having a specific gravity several times that of the confined liquid.

14. In sealing apparatus, the combination of two relatively movable walls, one of said walls confining a liquid under pressure, sealing means interposed between said walls, and acting to balance the pressure of the confined liquid, said means including a substance having a specific gravity several times that of the confined liquid, and being capable 01" remaining liquid at a temperature materially below the boiling point oi the confined liquid.

15. In sealing apparatus, the combination of two relatively movable walls, one of said walls confining a liquid under pressure. sealing means interposed between said walls, and acting to balance the pressure of the confined liquid, said means including a substance having a specific gravity several times that of the confined liquid, said substance being cheniically inert with respect to the confined liquid.

16. In sealing apparatus, the combination of two relatively movable walls, one of said walls confining a liquid under pressure, sealing means interposed between said walls, and acting to balance the pressure of the confined liquid, said means including a substance having a specific gravity several times that or the confined liquid, and being capable of re maining liquid at a temperature materially below the boiling point of the confined liquid,

. said substance being chemically inert to the confined liquid.

Signed by me this 21st day of January, 1926.

. EDIVARD J. LEVY.

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