US2460746A

US2460746A - Joint construction

Info

Publication number: US2460746A
Application number: US609270A
Authority: US
Inventors: Guthrie Thomas; Gordon R Evans
Original assignee: Allied Chemical and Dye Corp
Current assignee: Allied Corp
Priority date: 1945-08-06
Filing date: 1945-08-06
Publication date: 1949-02-01
Anticipated expiration: 1966-02-01

Description

T. GUTHRIE ETAL JOINT coNsTRc'rIoN Filed Aug. 6, 1945 Feb. l, 1949.

INVENToRs Patented Feb. 1, 1949 JoIN'r CONSTRUCTION YThomas Guthrie, Albany, Calif., and Gordon R. Evans, Collingswood, N.J., assignors Iso-Allied Chemical & Dye Corporation, afcorporation of New York Application August 6, 1945, serial No. .609,270

s Claims. (o1. 285-10) 1 This invention relates to construction Iof fluid- Ltight joints particularlyadaptable forl use in connection with communicatingV gas conduits. f

,In the practice of chemical processes involving the manufacture of gases and the handling of the same in conduits usually of relatively large crosssection, it is often desirable to provide a gastight joint in a gas line one section of which is movable with respect to another. As one practical example, in the'production of hydrogen fluoride gas, fluorspar and sulfuric acid are reacted in a horizontal rotary furnace to form an HF gas which is'discharged from one end of the furnace thru an outlet opening or short pipe section the periphery of which is axially aligned with the horizontal axis of the furnace and which rotates with the furnace shell. This voutlet opening is connected by some kind Vof a joint to a stationary flue serving to conduct the 'gas `stream to the subsequent l gas purification and HF recovery stages of the'process. While the rotating furnace outlet, and the stationary gas main are designed so` as to be at least theoretically coaxial, it is Well known that in actual operation these elements are almost-.always out of. alignment to some 'greater or lesser extent. In the past, this circumstance has Acaused considerable difficulty in connection with the construction .of leakproof joints between the rotating furnace andthe fixed pipe.` The-usualpacked gland type of joint 1has proved inadequate, particularly after the apparatus hasbeen inuse` fongsorne period of time. Tendency for gasl leak-ageat the joint has been so pronounced that,`particu1arly in the manufacture of noxious gases, it has been thepractice almQSt universally to operate, at least the gas ,generating portionof the system under negative pressure in orderto prevent escape of harmful gases to the atmosphere andavoid injury to workmen. Since commercially available joint constructions of previous design have not been gasproof, the result-of negative pressure operation has beenfinltration of air thru the connecting joint to` such an extent as to dilute thev gas stream as much as50,% by volume. This difculty requires theV use of gas purification and recovery apparatus, substantially larger thanwould be needed if infiltration of air from the atmosphere could beavoded.,

. `-This invention `aims to provide a construction r which'affords a gasproof seal between two apparatus elements, `at leastone lof Vwhich is movable with respect tothe other, even if such elements are substantially out of alignment during operation.

the furnace and the pipe.

I The invention, itsobjects and advantages will appear from the following description takenin connection with the accompanying drawings in whichFig. 1 shows partly in. elevation and' partly in section a preferred embodiment, and Fig. 2 shows a section on line 2-2 of Figrl.

The improvements of the invention are particularly adapted for use in. situations in which oneconduit section rotates and the other isstationary; both sectionsfrotate but one rotates at a higher velocity than the other; and both sections rotate but in opposite directions.4 s A ToeXemp-lify utility fV o'neembodiment of the inventionpFig. f1\ illustrates application thereof in connection with manufacture of hydrogen fluoride gas. In Fig. 1, I Il indicates in section the gas outlet end of a horizontal cylindrical furnace rotatably mounted on roller supports, one of which appears at I I. A circular opening I2 in the vertical end wall of the furnace affordsan outlet thru which lgas is discharged fromv the furnace, it being apparent that the periphery I3 of the outlet is apart of and rotateswith the furnace. The main 'gas conduit' I4 is stationary and is held in position by a support I5. Fixed on the end of pipe Il is flange Il. The adjacent end of ashort pipe section I 9, constituting a portion of the seal assembly, has fixed theretol a similar f l-ange (20'. The two anges `are-held together by bolts not shown, and thus pipes I4 and I'9 form the stationary gas conduit. While pipe I4 and outlet opening IZ appear coaxial on the drawing, it will be understood that, because of irregularities arisingfrom wear and tearV and warping caused byvheat, the. axis of rotation of furnace I0 is variable, and'in operation vthe` axes of opening I2 and pipe I4 are almostjalways out of`r alignment which results ina substantially continuouseccentric rotation of periphery` I 3; `Further, wear and tearuon roller, I I1 and the` associatedtracl; causes the furnace to have a small but appreciable axial movement, relative to the fixed pipe It. Both of these movements contribute to gas leakage at the connection between L In accordance with this invention the foregoing diculties are Voverscome byprovision of a joint constructed so as to permit relative eccentric and/or axial movement between the furnace and the outlet pipe, and at the same time-prevent escape of gas if the furnace is operated under positive pressure or to prevent the ingress of air if the system is operated under negative pressure.

Fixed incastight ,relation on the end wall of the furnace, as byweldng, is a bearing ring braided copper and lead wool.`

place.

` seal-ing relation.v neededv to eect this action is transmitted thru 22, having a machined sealing f-ace`23 of substantial radial dimension, which rotates with the furnace. A wear ring 25 having a machined surface 26 provides a second sealing face which co- 'acts with face 23 of bearing ring 22 to form a sealbetween thexed and rotating parts of the apparatus.y While snugly fitted to the outside` of pipe section I9, the inner periphery of wear ring 25 is not fixed thereto but is mounted so as to permit axial movrnent relative to the fixed gas outlet conduit. Ring 25 is preferably provided with one or more ducts 29 by means of `which the contacting faces of rings 22 and 25 may be lubricated.`

` sure needed to hold ring 25 against ring `22 is not It will be noted from the drawing that the f inner peripheries of bearing ring 22 and of the opening I 2 in the Iend wall of the'furnace are substantially spaced apart radially from the adjacent outer periphery of pipe section I9 which projects into the furnace. This Vconstruction permits substantial eccentric and/or axial movement of thefurnace without causinga metal-tometal contact between'the furnace end wall and its attached bearing ring 22, and the fixed pipe I9. Thus, the annularspace between the. perphery I3 of furnace wall opening I2 and bearing ring 22 on the one hand', andthe outer surface of the i-nner end-of pipe I9 on the other, form an annular =portof substantial dimension thru which gas tends `to egress from; or ingress y to the furnace. Assuming operation of the fur- Y movably associated inner perpihery of ring 25 and the contiguous outer periphery of pipe section :|9. To prevent gas escape by the latter route, ring 25 .is recessed to receive'an annular ringof packing 30 which may be made of any suitable material such as graphited asbestos, The 'packing is held in place by any annular disk 32 shown in section in Fig. land in lelevation in Fig. 2, which rdisk may be connected to wearring 25 by means of bolts 34. Disk-32 may-be mounted on wear ring 25 so as to nesiliently hol-d packing 30 in l Flange 20 is provided with a series of threaded holes adapted to receive correspondingly threaded enlarged portions 36'of follower bolts 31.- As

shown in Fig. 1, the inner endof a1 bolt 31' projects into. a follower bolt seat hole 39 drilled into the outer face of wear ring 25. A Mounted on each bolt is a spring 4!, one Iend of which is seated against one face of enlargedthreaded portion 36, and the opposite'l end vbearing against the outer lface of wear ring25. The outer end of a bolt3'lv projects thru an lopening 42 in flangev I1 transmitted thru packing 30, the packing is not subjected to any unequal lateral pressures because stress caused by position variations of comlponent parts due tol axial or eccentric motion are relieved by the springs. Packing pressure, effected by ring 32, is independent of spring pressure and the packing is subjected only to normal wear incurre-d by Iaxial motion over the louter surface of -pipe section I9. The spring follower bolts 3'IV permit the wear ring 25 to be axially but not rotatably movable with respect to the fixed pipe I9, and the diameters .of follower bolt seatholes 39 are adequate to prevent binding during eccentric motion of thel furnace.

The invention i-s subject to several modifications. While in the apparatus as shown, bearing ring 22 is fixed directly to the furnace-Wall, it will be understoodthat the furnace might be j provided fwith a shortoutletzpipetwhich isfixed to and rotates with the furnace' in which case bearing ring 22 may be fixedly mounted 0n the lperiphery of the outer end ofsuoh outlet pipe. Further, in Fig. 1 the relationship of the operative parts may bereversed, that is,lthle apparatus represented by furnace Wall I9 and the attached bearing ring 22 vmay be fixed, while the conduit formedibyqpipe sections I4v and I9, the anges I'IaIidZ, wear ring 25 and the associated parts may be rotary. The conduit formed by pipe sections I4 and I9may be used to feed solid material into arotary'chamber-vinwhilcha gas-forming reaction is taking placa The invention may be adapted to prevent gas-'leakageat the connection between the'reaction chamber andan asnace I0 of the drawing may be a fixed reaction chamber and thejpipe sections I4 and I9 of Fig. 1

andis providedwith a squared head 45 by means of which the position of threaded enlarged portion 36k of bolt 31 maybe adjusted axially with respect to flange 2l); y v

In operation, follower bolts 31 are adjusted to move, thru the `compressive action of springs 4I, the. wear ring 25 far enough toward bearing ring 22 soas to form a fluid-tglit-seal between Vthe sealing faces 23 and29. It vwill be noted that ythesprings iactdirectly 'on wear ring 25 to hold the contiguous'faces of rings 22 and 25 in Nonev of the spring pressure may be replaced by a solid shaft as-the rotary shaft of an agitator. In this situation, flanges I'I and 20, lwear ring .25 and the associated parts rotate withI theshaf-t, the sealing off of any tendency for gas 'to escape from the inside of the fixed reaction chamber being as previously described. V f

We claim 1. A joint construCtiOll assembly compsing a pair of adjacent members associated Yand arranged inA substantially spaced-apart and in nonfluid-tight relationand to vprovide a port thru which fluid may egress or ingress, atleast one of said -members being rotatable with respect to the other; a bearing ring fixed to'and projecting from the outsidev of one of said 'members encircling but spaced substantially from said other member to constitute a portion of the wall of said port, and forming by its outwardly directed surface a rst sealing face;A a wear ring, snugly associated with, projecting.' outwardly from, carried v by but axially movable with vrespect to said other member andV forming by V'a'surface thereof a second sealing face directed toward and adapted to contact said rst sealing face in fluid-tight relation; packing movable with said Wear ring and mounted immediately between said wear ring and said other member for preventing passage of fluid `between said -wear ring; and said other member,

adjustable compression means carried by said other member and arranged externally of both of said members, said compression means acting directly on'said wear ring :to maintain said sealing -faces in fluid-tight relation, said faces being constructed and arranged to form a seal surrounding said port and to permit substantial eccentric movement of said members without breaking contact between said sealing faces; said members, said rings and said adjustable compression means being so constructed and arranged as to facilitate ready7 adjustment of said compression means from without said assembly in its entirety.

2. A joint construction assembly comprising a pair of adjacent members associated and arranged in substantially spaced-apart and in nonfluid-tight relation and to provide a port thru which fluid may egress or ingress, at least one of said members being rotatable with respect to the other; a bearing ring fixed to and projecting from the outside of one of said members, encircling but spaced substantially from said other member to constitute a portion of the wall of said port, and forming by its outwardly directed surface a first sealing face; a wear ring, snugly associated with, projecting outwardly from, carried by but axially movable with respect to said other member and forming by a surface thereof a second sealing face directed toward and adapted to contact said first sealing face in fluid-tight relation; packing mounted to prevent passage of fluid between said wear ring and said other member, adjustable thrust means carried by said other member and arranged externally of both of said members, said thrust means acting on the wear ring to maintain said sealing faces in fluid-tight relation, said faces being constructed and arranged to form a seal surrounding said port and to permit substantial eccentric movement of said members without breaking contact between said sealing faces; said members, said rings and said adjustable compression means being so constructed and arranged as to facilitate ready adjustment of said compression means from without said assembly in its entirety.

3. A joint construction assembly comprising a pair of adjacent members associated and arranged in substantially spaced-apart and in noniiuid-tght relation and to provide a port thru which fluid may egress or ingress, at least one of said members being rotatable with respect to the other; a bearing ring fixed to and projecting from the outside of one of said members, encircling but spaced substantially from said other member to constitute a portion of the wall of said port, and forming by its outwardly directed surface a first sealing face; a Wear ring, snugly associated with, projecting outwardly from, vcarried by but axially movable with respect to said other member and forming by a surface thereof a second sealing face directed toward and adapted to contact said first sealing face in fluid-tight relation, packing movable with said wear ring and mounted immediately between said wear ring and said other member for preventing passage of fluid between said wear ring and said other member, a ange fixed to and projecting outwardly from said other member, adjustable compression means carried by said flange, said compression means comprising a plurality of bolts each threadedly connected to said fiange, a spring carried by and movable by each bolt to compressively abut the wear ring, and means to adjust each of said bolts axially of said flange to Vary the compression of each of said springs; said compression means being arranged externally `of both of said members and acting directly on said wear ring to maintain said sealing faces in fluid-tight relation, said faces being constructed and arranged to form a seal surrounding said port and to permit substantial eccentric movement of said members without breaking contact between said sealing faces; said members, said rings, said ange and said adjustable compression means being so constructed and arranged as to facilitate ready adjustment of said compression means from without said assembly in its entirety.

THOMAS GUTHRIE. GORDON R. EVANS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,470,587 Somes Oct. 9, 1923 2,038,855 kRosenblad Apr. 28, 1936 2,220,965 Kohler Nov. 12, 1940 2,334,663 Whitney Nov. 16, 1943 FOREIGN PATENTS Number Country Date 400,379 Great Britain Oct. 26, 1933