US1812282A - Vulcanizer and method of vulcanizing - Google Patents

Description

June 30,1931. E. BLAKER VULCANIZER AND METHOD OF VULCANIZING Filed July 19, 1923 zo'schedule of temperature and pressure;

, f tion in its preferred form', part"being* broken 1 I v f to admit compressedair jand steam to the in:

jector'19, wherein th'eyjare intimately mixedl I and sothat they pas's as a"compo'site'fluid the inletlnanifold'l lg from which they are I 'Patented c1931 ERNEST lBLAlKER,

o L A zEeIA -D DYOFQW NI i G- Application filed .l'u1y719, 1228' Serial No} "293,910. l

This invention relates to the vulcanization of rubber articles in mixture of gases such as 1 air andsteamias iirthe case oi employing" v steam at a suitable"partiahpressure to g1ve' 5 the desired vulcanizing temperature and air 7 i at a suitablepartial-pressure to provide a total pressure o-fair and steam adequate to compact the article. 1' V In vulcaniz'ing inner tubes upon, iriandrels; for eXample,-it is desirable tof'pro'vide'thor ough and uniform; admixture" of the air" and steam throughoutltheinteriorof the vulcanizerv from the beginning ofthe operation', while the pressure is being'built up, in order is to avoid unequal heat-softening and unequal vulcanization of; the articles, and my chief objects are to provide improved procedure and apparatus for that purpose and to provide a suitable ratio of the fluids'and an improved The single figure of i the accompanying drawing is a side elevation offapparatus embodying and a'dapted-to-carry out my invenfllaway'and insectio'nl- 1 a Referringto thedrawing, 10 is a horizontal vulcaiiizer'of theusualsingle-wall construe tion'and11is a hinged door'at one end there of. The work, here" shown as consisting'of 30 inner tubes '12; 12buil't'upon cylindrical mm 1 drelsj12, 12, is'mounted' upon a wheeled Utruck'13. "The tubes 12'have their respective ends tightly bound to the mandrel s' with moist tape,thefintermediate portion ofthe tube be.;

ing unconfined and exposed. a a

' Positioned inside the vulcanizer' 10-.a'l'ong the bottom thereof isaninlet manifoldlt comprising a horizontal-pipe having its up vper side formed with apertures 15, 15,ianda similar pipe 16 formed with apertures 17,17 on its under side ispo'sitionedalong the top ofthe vulcanizing chamber'and comprises an" outlet manifold therefor.

The inlet manifold 14c.v

's connected at its middle with-Va supply pipe 18which leads through the vulcanizer wall from the outlet port of an inject0r19. The outlet vmanifold 16 is connecteda t its middle with'a pipe 20 which extends through the vulcanizer wall- 5 to the suction-inlet port of the injector l9.

I A Vent pipe 21 providedwitha'shut oif valve 21 branches from th'e'pi-pe'20', and the latter, a between the-vent pipe 21'and the vulcanizer 1 is provided with a'shut-ofi' valve 22. "Beyon i the vent-plpe 21 the pipe-20 is providedwith' OE'AKRoN, 0mm ss-mma mome eoonnioii COMPANY; or NEW YYORK,)N.1-Y.,1A CORPORATIONOF NEW; YORK fluid through the pipe"2Oftowardthe-vul I canizer', and'between said check-valve; and-,

the-"injectorilQ thepip 20visconnect'ed to a high p'ressure' air line 245 the latterheir-1g; provided witha shut-ofi-va1ve '25." Thepres sure-inlet port of the injector 19 is connected to a'high-pressu're steamline 26 which? is pr'o' vided with a shut-off ival ve '27. The V1114 cania'erg 10 is provided with a drain-pipej28 'leadlng to a steam-trap 29=,'andalso'with temp'erature and pressure gauges 30 and 31 re spectively:

In the operation of the apparatus; after p the work" has b'een wheeled into*-the=-vul@10 canizer the door; ll is closed and sealed; the V valve 21 in the vent-pipe'21-iselosedgfand I V ,1 the valve 22 is opened or allowed; to iremain The valves 25;-and 27 are then opened opena distributed throughout thelengtlr of the v'ul'aj f flowingfromrsaid"injector; aThearr'angement' is such that the air'and steam are iiitimately;

mixed" before they enter the vulcanize'r; 'anl' by efiecting withdrawal of'air' fromthetop of thevulcanizer as the'compo'site fluidenters jw I the i bottom the'reoflvI- obtain a uniform dis tribution of .the "composite? fluid within the" i vulcanizer, and-"any oti said fluid-f which may be drawn off through the pipe 2O is returned j '7 1 to the-vulcanizer' by reason of the closed oir- 1 I v cu'it comprising the -ipipes' 1'8,-

and} injec tor19. 1 U

The valves 25:, '27-'xpreferably are opened 1 to such extent With relation to each other that the air-steam mixture Within the vulcanizer attains a temperature of 220 and a pressure of pounds in about 7 minutes. The airvalve 25 is then closed and steam alone is permitted to continue to flow into the vulcanizer until a temperature of 290 is obtained therein, at which time the pressure Will be 120125 pounds, and this condition is maintained for about 5 minutes. In the operation as thus far described the unvulcanized rubber of the tubes 12 softens under the eflect of the heat and concurrently is compressed by the composite fluid, With the result that all air entrapped Within the tube is greatly reduced in volume and the tubes are compacted against the mandrels.

The valve 21 in the vent-pipe 21 is then opened for a time to permit the escape of com posite fluid to reduce the pressure thereof in the vulcanizer, the valve 27 remaining open to maintain the vulcanizing temperature therein. When, after 5 or 6 minutes, the pressure has dropped to about 55 pounds, the vent-pipe is closed, and the drain pipe 28 is opened to permit the escape of any Water of condensation from the vulcanizer, through the steam trap 29, and approximately the then existing condition of temperature and pressure is maintained in the vulcanizer until the Work is completely vulcanized by con trol of the steam inlet, although some of the air remaining in the vulcanizer escapes the steam trap.

At the end of the vulcanization the valve 27 is completely closed and the valves 2]. and 22 are opened to vent the vulcanizer, after which the vulcanizer is opened and the Work removed, and the operation as described is repeated.

The concurrent injection of the air and steam from the beginning assures that the Work will be adequately compressed as it softens, before a surface skin has been vulcanized thereon, as is likely to occur When the steam in substantial quantity is admitted to the vulcanizer before the air. Removal of the air from the vulcanizer after vulcaniza tion starts avoids the possibility of oxidation of the rubber, and expedites vulcanization, since better heat transfer is obtained from steam alone than from an air-steam mixture.

The initial mixing of the steam and air by means of the injector, and also the Withdrawal of air from the vulcanizerand the circulation of the mixture through the vulcanizer by means of the injector, assures a uniform mixture, which is to say a uniform distribution of each of the fluids throughout the interior of the vulcanizer so that local cool spots or air pockets are avoided.

Modifications of my invention are possible within the scope of the appended claims.

I claim:

1. The method of vulcanizing rubber articles Which comprises enclosing the articles in a vulcanizer, mixing a heating fluid and a pressure fluid, conducting the mixture into the vulcanizer the rubber articles therein be ing exposed to the mixture, and concurrently Withdrawing fluid from the vulcanizer and adding it to the mixture'of fluids passing into the vulcanizer.

2. A method as defined in claim 1 in Which fluid is Withdrawn from the vulcanizer and added to the mixture of fluids passing into the vulcanizer, in part, at least, by the kinetic energy of the said mixture.

8. The method of vulcanizing externally unconfined rubber articles Which comprises applying to the articles a mixture of air and steam and thereafter lowering the pressure While maintaining a vulcanizing temperature by replacing a part of the mixture With steam.

4. In a vulcanizer the combination of a vulcanizing receptacle having an inlet and outlet, a piping circuit connecting said inlet and outlet, and means for admitting fluid pressure to said circuit, said means being so arranged that the admission of said fluid induces a circulation of fluid through the vulcanizing receptacle and piping circuit.

5. In a vulcanizer the combination of a vulcanizing receptacle, an inlet and an outlet manifold therefor, a piping circuit connecting said inlet and outlet manifolds, an injector in said circuit, and a fluid pressure line so connected With said injector as to induce a circulation of fluid Within the vulcanizing receptacle and piping circuit When pressure fluid is admitted to the injector.

6. In combination, a vulcanizing receptacle having an inlet and an outlet, a circuit of piping connecting said inlet and outlet, an injector in said piping circuit, and tWo pressure-fluid lines connected With said piping circuit in such relation to the injector as to cause fluids flowing therefrom to the injector to be intimately admixed in passing therethrough.

In Witness whereof I have hereunto set my hand this 5th day of July, 1928.

ERNEST BLAKER.

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