US2534865A - Protective seal for vulcanizing apparatus - Google Patents

Description

Dec. 19, 1950 A. N. GRAY 2,534,865

PROTECTIVE SEAL FOR VULCANIZING APPARATUS Filed June 2Q, 1947 MERCURY INVENTOR A. N. GRAY A T TORNE V Patented Dec. 19, 1950 UNITED STATES rArENT oFFxcE PROTECTIVE SEAL FOR VULCANIZING APPARATUS Alvin N. Gray, Joppa, Md., assignor to Western Electric Company, Incorporated, New York, N. Y, a corporation of New York Application June 20, 1947, serial No. 755,987 a 11 Claims. o1.1s e) covering of vulcanizable compound including sul phur as an agent therein, and then the covered core is advanced through an elongated vulcanizing tube to vulcanize-the covering. In a vulcanizing tube having steam at a high temperature and under high pressure therein, the heat of the steam vaporizes latent moisture in the hygroscpic elements of the core; The steam in the vulcanizing tube picks up hydrogen sulphide derived from the sulphur used as a vulcanizing agent in the vulcanizable compound extruded upon the core.

A seal has sometimes been positioned at the endof such a vaulcanizing tube, and cold water has been introduced into the seal. The seal serves the dual purpose or preventing the escapeof steam from the vulcanizing tube into the atmosphere, and of cooling the covered core to condense the vaporized moisture originally contained in the hygroscopic elements of the core and thereby prevent bursting of the covering of vulcanized compound thereover. The pressure of the water has sometimes been controlled by apparatus such as that disclosed and claimed in copending application Serial No. 702,601, filed October 11, 1945 by A. Stiegler for Continuous Extruding and Vulcanizing Apparatus. Such a pressure controlling apparatus includes a U- tube including a float chamber containing mercury and a float resting on the mercury in the float chamber for actuating suitable waterpressure-changing elements. Steam pressure is transmitted directly by steam to the float chamber, and water pressure is transmitted to the other end of the U-tube. In the past, the steam or condensate carrying hydrogen sulphide therewith has come into direct contact with the mercury in the float chamber and mercuric sulphide,

and due to the reaction between the hydrogen sulphideand the mercury a solid is formed, which cakes up the float and the mercury chamber. This has a deleterious-action on the operation of the-pressure controlling-apparatus.

An object of the invention is to provide new and improved protective seals.

A further object of theinvention is to providenew and improved protective seals for preventing contact between hydrogen sulphide in steam lines connecting vulcanizing tubes of continuous extruding and vulcanizing apparatus and mercury in float chambers of pressure regulating systems associated with such apparatus.

A protective seal illustrative of certain features of the invention includes a precipitating chamber positioned between a float chamber con taining mercury'and a steam line having hydro- 'gen sulphide laden steam therein, and a precipitating agent positioned inthe precipitating chamber for precipitating the sulphide to pre vent'contact between the sulphide and the mercury.

A complete understanding of the invention' maybe'obtained from the following detailed description of a protective seal forming a specific embodiment thereof, when read in conjunction with the appended drawing, in which the only figure is an enlarged, fragmentary, partially sectional, side elevation of a portion of a continuous insulating and vulcanizing apparatus and a protective seal embodying the invention.

Referring now in detail to the drawing, there is shown therein a portion of a continuous extruding and vulcanizing apparatus for forming and vulcanizing a protective covering Ill (Fig. 1)

over a core I I to form a covered conductor. The core it also includes a textile covering (not shown), such as cotton, or the like, which is hygroscopic in the manner described in the above-mentioned copending application. The covering H7 is composed of a vulcanizable compound, such as a jacketing compound containing rubber or a synthetic rubber-like material and sulphur as a vulcanizing agent.' The covered core is advanced through an elongated steam-jacketed vulcanizing tube 22 into which steam under high pressure is supplied by suitable means (not shown).

T der a high but fluctuating pressure heats the covering Hi to a high temperature. I I .and pressure vulcanizezthe. covering 10, but the.

This heat The steam vulcanizes the vulcanizable compound, and, in so doing, be-

heat of the covering l heats any moisture contained in the textile covering to temperatures at which the moisture would be volatilized under atmospheric pressure. As long as a pressure substantially above that of atmosphere is kept 5 on the covering H], the moisture thereunder does not volatilize.- wBut-if the pressure thereon is reduced to that. of atmosphere before themoisture is cooled, the moisture under the covering l9 volatilizes and ruptures or blisters the cover- 10 ing l0. Cold water under a high pressure is supplied through a pipe 28 to theseal andcools, 55;: the moisture in the covered core H sufficiently' to prevent such damage.

The cold water is kept at a pressure:substan--; l5 tially the same as that of the steam by a differ- 2 Y ential pressure controlling device .29, which, ex-.. cept for a protective seal 30, is identical with that disclosed and claimed in the above-mentioned; copending application of A1 Stiegler. The differehtial: pressure. controlling device: includes a U-tube 3i and a float chambere32; ,-Mercury.po-; sitioned in the U-tube 3| serves to support-a fioatc33. in the .float chamberg32, and' the float serves-toactuate the-'controller.- -A pipe 41 filled with-.oil connects-the upper portion-of the float. chamber, the-- upper. portion of which: also is filled with oil, to a manually operable valve 43 leading to the interior of. a precipitating tank45. Theprecipitating.tank-isfilled with a-hydrogen sulphide: precipitating solution :such :as, for example 'a solutionrotl copperchloride, of greater density; thamwateu. and oil, andxhas acollecting portion 46, a;drainq41 and a refill spout 48. The, precipitatingsolutionds heavier than the-oil in the pipe 42 and ispositioned ata-lowerlevel than, the-floatcchamber32 so that-the; oil prevents contact between the mercury and the precipitae-v ting solution but :transmits pressure therebetween.

A pipes, having a: spout 50 and filledgwith 4e water.- connectstheiprecipitatingitank to-a check. valveeil, rwhichd's connected to asteam condenser 52'; iThejcheck-valve 5| does not normally: affect the rest of the apparatus, ,butwhen; a highs vacuum is: formed: in a.1.pipe-54 connecting'the condenser .-to theivulcanizing'tube-22, as when steam is initiallyzsupplied to :the vulcanizing tube andashootsxpast'rthe pipe 54 at a high, velocity, the checkwalve lets atmospheric air into the pipe 49 andsthepondensernto preventthecontentsof the protective seal; 311 from ,being drawngtherefromzm:

In the operation .of the protective-seal 13,0, the--.. pressure of the steam in the vulcanizing tube 22 is transmitted to, the float chamber 32 by steam 55 through thezpiper 54, by water .in the.condenser-,- 52 and the pipe 49, by the precipitating solutionin the (precipitating tank 45 and by oil in the valvef43 and the pipe"4 2.

The; water in the-condenseriZ and the pipe 49 isthe condensate-from steam entering --thecondenser, and hence is'ladenwith the-hydro-- gen sulphide ?carriedby the. steam: Any hydrogensulphide-which enters the spout;5il of they piped-9 is immediately; precipitated "by reaction with the m'etallicj-saltin the precipitatingsolution .in:.the-,sp'out; .and .the I precipitate; copper sul-. phide,.-:if a :copper chloride solution 1 is; used; settles into the collectingiportiony leof the precipi- Q i tating tank. The oil between: the "precipitating:.:: solutionand theamercury prevents contact there betweenfby. gravity? Thus,-'hydrogenzsulphide is kept;fronr;contacting--the1.merc.ury .so that the mercury is i kept rcleanr,

Whenever "the .precipitating:solutiombecomes}:v {[5 weak, the valve 43 m closed and the drain 4'! is opened whereby the solution flushes the collected precipitate out of the collecting portion 46 of the tank as it is drained from the tank. The drain 4"! then is reclosed, the refill spout 48 is opened, and a fresh quantity of the precipitating solutionzis pouredinto the 'tank 45 through the refill. spouteto: fill the tank-.45. Thereflll spout is closed again and the valve 43 is reopened. The above-described apparatus serves to keep mercury in the float chamber 32 from being contaminated'by hydrogen sulphide, so the pressure controller is kept in operative condition even though thesteamsin the vulcanizing tube 22 is laden-withhydrogemsulphide. Also, there is no solid LObStLllCtlOl'l between the vulcanizing tube and..the fioatchamber so that transmission of pressure from the steam in the tube to the mercury-.is:n'ot: prevented.

The precipitating tank :is made sufficiently largesto prevent-the necessity-of, draining and refilling it frequently. Jhe precipitatingsolution efiectively prevents contactnbetween the hydrogen sulphide and. the.oil, .sinc e the spout 50. ex-- tends so far into the .tankvthathydrogensulphide. doesnot filter. through :the-oil and-come. into C0119,

tactwith rthemercuryh What, isclaimed is:

1. In an .apparatus includinga- U-tube for holding mercury and .a conduit for .fluidJaden with a chemicalelementcapable of forming asalt.

with mercury,.the:improyement which comprises.

a chamber communicating with both the conduit and the .U etube; asolution positionedin-the cham-. ber for removing the-chemical elementinsuch: a fluidin theconduit and. for transmitting pressure from theefluid toward-mercury held in them U-tube; and a; pressure-transmitting fluidim-; miscible with ,the-solutioniandl the mercury: posi-;

tioned therebetween.

insoluble sulphide and for transmitting pressure from the fluid towardmercury held in the U-tube,

and,,. a, pressureetransmitting fluid immiscible with the solution and the mercurypositioned between thesolution andthe mercury.

3. In an apparatus including a-mercury filled. U-tube anda conduitfor fluid .laden with hydro-'1 gen sulphide the improvement-which comprises- I a chamberwpositionedgbetween and-communi' eating with both the conduit and one end'ofthe U-tube,-a copper chloride solution. positioned'in the chamberior reacting with thehydrogen sulphide in; the fluidin the conduit to form an insoluble sulphide. and. for transmitting pressure from .thefluid toward the mercury in the 'U-tube, ands-a. pressure-transmitting 3 fluid immiscible with the solutionand the-mercury positioned. be---, .1

tween the solutionand, the mercury.

the second fluid to prevent contact between it and the first-mentioned fluid'and for transmitting pressure from the second fluid toward the first-mentioned; fluid, and a pressure-transmitting sealing fluid positioned between the precipitating fluid and one of the other fluids and immiscible therewith.

5. In an-apparatusincluding a chamber for holding mercury and a second chamber for holding a fluid having hydrogen sulphide therein, the improvement which comprises means including a third chamber for connecting the firstmentioned chambers and being in communication therewith, a sulphide-precipitating fluid contained in the third chamber for reacting with the hydrogen sulphide of the second fluid to form an insoluble sulphide toprevent contact between it and mercury in the first chamber and for transmitting pressure from the second fluid to the mercury, and a pressure-transmitting sealing fluid immiscible with mercury and the sulphide-precipitating fluid and positioned therebetween.

6. In an apparatus including two containers filled with fluids including chemically reactive elements, a device for connecting the two containers together in communication with each other and for preventing contact between the two fluids, which comprises a chamber positioned between the two containers and connected thereto, a precipitating fluid for precipitating the reactive elements of one of the fluids in the containers to prevent contact between the reactive elements of the last-mentioned fluids, a pressure-transmitting, sealing fluid immiscible with the precipitating fluid and one of the other fluids positioned therebetween, means for draining the chamber to remove the precipitate therefrom, and means for refilling the chamber.

7. In an apparatus including a container, a container having mercury therein and a second container having therein a fluid laden with an element capable of forming a salt with the mercury when in contact therewith, a device for connecting the two containers in communication with each other and for preventing contact between the mercury and the fluid, which comprises a chamber positioned between the two containers and connected thereto, a precipitating fluid for precipitating the salt-formin|g element of the fluid in the second container to prevent contact between that element and the mercury, a pressure-transmitting, sealing fluid immiscible with the mercury and the precipitating fluid positioned between and in communication with the mercury and the precipitating fluid, means for draining the chamber to remove the precipitate therefrom, and means for refilling the chamber.

8. In an apparatus including a container having mercury therein and a second container having therein a fluid including hydrogen sulphide a device for connecting the two containers together in communication with each other and for preventing contact between the mercury and the hydrogen sulphide, which comprises a chamber positioned between the two containers and 9. In a continuous vulcanization apparatus in eluding an elongated vulcanizing tube, a cooling and sealing unit positioned at the exit of the vu1-" mined ratio between the pressures of the steam and the water, said controlling means including a mercury U-tube for retaining mercury therein, the improvement which comprises a device for protecting the mercury from contact with the steam and for transmitting pressure therebetween, which comprises a generally U-shaped precipitating passage, a hydrogen sulphide precipitating fluid in the precipitating passage, a conduit for connecting one arm of the precipitating passage to one arm of mercury U-tube, a sealing fluid non-reactive with and immiscible with the mercury and the precipitating fluid positioned in the conduit, said sealing fluid having a density lower than that of the precipitating solution, and a second conduit for connecting the other arm of the precipitating passage to one of the cooling and sealing unit, the water-supplying means and the vulcanizing tube.

10. In a continuous vulcanization apparatus includin an elongated vulcanizing tube, a cooling and sealing unit positioned at the exit of the vulcanizing tube, means for supplying steam under a high pressure to the vulcanizing tube, means for supplying water under high pressure to the cooling and sealing unit and means for controlling one of the steam-supplying means and water-supplying means to maintain a predetermined ratio between the pressures of the steam and the water, said controlling means including a mercury U-tube for retaining mercury therein, the improvement which comprises a device for protecting the mercury from contact wit one of the steam and the water and for transmitting pressure therebetween, which comprises a generally U-shaped precipitating passage, a hydrogen sulphide-precipitating fluid including copper chloride and having a predetermined density in the precipitating passage, a conduit for connecting one arm of the precipitating passage to one arm of the mercury U-tube, oil having a density less than that of the precipitating fluid and positioned in the conduit, and a second conduit for connecting the other arm of the precipitating passage to one of the cooling and sealing unit and the vulcanizing tube.

ll. In a continuous vulcanization apparatus including an elongated vulcanizing tube, a coolconnected to the second container, a copper ing and sealing unit positioned at the exit of the vulcanizing tube, means for supplying steam under a high pressure to the vulcanizin tube,

means for supplying water under high pressure to the cooling and sealing unit and means for" controlling one of the steam-supplying means and the water-supplying means to maintain a predetermined ratio between the pressures of the steam and the water, said controlling means including a mercury U-tube for retaining mercury therein, the improvement which comprises a device for protecting the mercury from contact with one of the steam and the water and for transmitting pressure therebetween, which comprises a vertically disposed U-shaped precipitating trap, a sulphur and hydrogen sulphide precipitatin fluid of a predetermined density positioned in the precipitating p 81 conduitlincludinsra manually: operabl valve for connecting: Qnearm of the precipitating trap to one armofthemercury u-tube, a sealingfluid non-reactivewith and immiscible with the mercury and the precipitating fluid positioned intheconduit, and having a density less than that-ofthe precipitating fluid, a second conduit for connecting the other arm of the precipitating trap to one of the cooling and sealing unit, the water-supplying means and thevulcanizing tube, means for draining the precipitating trap, and means for refilling the precipitating U-tube.

' I ALVIN N. GRAY.

8 REFERENCES ,CITED The following references are of recordinthe file of this patent:

UNITED V STATES "PATENTS Number Name Date 2,105,127 Petroe Jan, 11;1938 2,307,575 --Davis Jan. 5,;1943 2,418,166 Dinmore, Jr.,-et al. Apr. 1.- 1947 10 2,426,341 Canfield Aug. 26,- 1947

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