US3477500A

US3477500A - Apparatus for high-speed treatment of continuously moving material

Info

Publication number: US3477500A
Application number: US678662A
Authority: US
Inventors: Stuart B Sear
Original assignee: STUART B SEAR
Current assignee: STUART B SEAR
Priority date: 1967-10-27
Filing date: 1967-10-27
Publication date: 1969-11-11
Anticipated expiration: 1986-11-11

Description

Nov. 11, 1969 S. B. SEAR 3,477,500

APPARATUS FOR HIGHSPEED TREATMENT 0F commuousLTMovmG MATERIAL Filed oct. 27, 1967 @TAM WQ Q A .\J Wr QJ E oww@ A A A A @mm Q. mm., Om B s||||1|r||||11|f1 .NW ww .MMMHHl/IIMIWIIMMMIHHNMHIWIU lfl .In PLQ. Amr/wm, I WA @A n. mm m, a. w wm l Nm S S m@ r D mm \\w\ hm A T i l .W/ QN -A @A A @A AT www .i m (0.

United States Patent U.S.-cl. 16s- 89 9 claims ABSTRACT oF THEDIsoL'osURE A rotatable hollow roll heatexchange device adapted for, high-speed continuous treatment of material passing about its peripheral surface and including a cylindrical outer shell having` an internal y,fluidheating chamber, means for circulating a. heating lluid through the chamber during rotation of the device, and sealing means disposed `between the rotatable and nonfrotatable portions of the heat exchange device for sealing the chamber against loss `of heatinguid therefrom and for facilitating the circulation of heating fluid therethrough; and wherein the sealing means includes rictionally-engaging relatively movable sealing surfaces positioned closely adjacent the axis of rotation of the device to minimize frictional wear on the surfaces.

iThis invention relates to an internally-heated, rotatable hollow roll heat exchange device adapted for high-speed continuous treatment of material passing abot its peripheral surface, and more particularly to a fluid heated rotatable roll having improved liuid circulating and sealing means to permit more eifective use of the roll during high-'speed operation.

"Rapidlyl rotating uid heated rolls are used extensively in eontinuous drying and heating operations. One typical application is' in the textile industry where such rolls are employed to heat textile yarns passing about their peripheral surfaces. Such rolls are particularly desirable for use in the drawing or texturizing of synthetic continnous filament yarns, wherein the temperature of running thermoplastic yarns is raised during their highspeed line'ar movement about the periphery of the'rolls to facilitate reorientation of the molecularstructure of the yarn duringstretching and other reshapingof the laments of'the yarn.

` Such rotatable roll heat exchangers generally comprise afcylindrical outer shell having an internal fluid heating chamber, which shell is moutned for high-speed rotation on'a suitable'support -shaftand is provided with means for kcirculating a heating fluid, such as steam, through the heating chamber of the'shell during rotation of the roll.

To prevent loss of the heating fluid from the roll during rotation, V'suitable sealing means are provided between the rotatable and non-rotatable elements of the roll. The frictionally-engaging, relatively-movable sealing surfaces of such sealing means are generally located a substantial distancefrom the axis of rotation of the roll and have large areas of contact which sometimes also serve as bearing surfaces during rotation of the roll.

In the use of such rotatable rolls, particularly in textile operations,it is often necessary to employ Very high rotational speedsin order to obtain maximum efciency" in production. At these high rotational speeds, forces of dynamic imbalance are often created in the roll, 'causing oscillationfvibration, or other undesirable movement between th'e rotating and non-rotating elements of the device, which movement results in increased wear on the widely-spaced sealing surfaces ofthe roll and necessitates frequent shut-downfOr replacement of the seals. Also, location of the sealing surfaces of the roll a substantial ice distance from the axis of rotation correspondlrigl u creases the linear distance the'frictionallyiengfaging.tsurfaces must move relative to each other duringleach revolui tion of the roll, which factor further'in'crease's'the' wear on the sealing surfaces. fr le l1* "i Itis therefore an object of the present inventionf 'to-p vide an internally liuid-he`ated rotatableroll whereinthe sealing elements of the' roll'are so'cnstructed-am posi-3 tioned as to decrease, to a greatfextent, the-frictional wear of such sealing elements whichhas heretofotebeema major problem in the prior art devices. l A It is a more specific object of the' inventionto provide an internally fluid-heated rotatable.vholldwfroll-heatex change device adapted for high-speedcontinuousftreat ment of `material passing about its :peripheral surface wherein the sealing surfaces between thelrotatable -and non-rotatable elements vof A'the lldevice are f positioned closely adjacent theaxisl of rotation of the 'device to minimize wear of the surfaces 'during highspeed -f rotation. v It is another object-to provide such `a rotatable hollow roll wherein the sealing surfaces of the roll are generated about a common center located on the axis of rotation of the roll to facilitate sealing engagement of the surfaces in the event of disalignment of the rotatable and nonrotatable elements of the device or oscillation of the elements during high-speed rotation. It is an additional object of the invention to provide a rotatable roll of the type described wherein the rotatable elements of the roll are positioned about the axis of rotation of the device so as to minimize dynamic imbalance of the device during high-speed rotationy and wherein the iluid circulating means of the device are constructed to facilitate optimum distribution of the heating uid through the internal heating chamber of the rotatable roll.

Some of the objects and advantages of the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which:

FIGURE 1 is a side elevational View of a rotatable hollow roll heat exchange device ofthe present invention; FIGURE 2 is an enlarged cross-sectionall view of the device, with a center longitudinal portion .thereofremoved, taken generally along line 2 2 of F-lGUREl and `looking in the direction of the arrowsyandf, .l FIGURE 3 is an enlarged sectional-view of the sealing elements of FIGURE 2 exploded for` purposes of clarity. Referring more specifically touthe drawings, FIGURE 1 shows a rotatable roll heat exchange. device `-`10h01? the present invention which generallyincludes a non-rotatable or fixed outer support casing 12 of builtupcohstruction and a rotatable hollow 'roll section 14 which'is rotatably supported thereimThe casingfvlz of `the'heatexchange' device may be suitably mounted yon a support frame' 16, a portion of which is shown, by Vmeans'ofa radiallyextending flange 18 attached to and surfrounding'fthe'outer periphery of the casing; d

The rotatableroll section 14 maylbest he described by reference to FIGURE Zand includes a cylndricalouter shell20 of heat-conductive material, such as stainless steel, having end Walls 22, 24 defining withfthe :shell fan' internal fluid heating chamber 26. `The outer shell20is` mounted on the end of'an elongated hollow supportshaft 28 with its longitudinal axis in alignment with'zthe longi;y tudinal axis of theshaft. A tapered-portion 28a :ofthe shaft sealably engages a correspondinglyftap'ered openinginthe end wall 24 of the shell and the vfshell 120 -is re `A4 movably secured to the shaft by means 'fonuts 3.0,32 which threadably engage thefendrof thev shafts-and about the inner face of end wall 24;'The `inner Aperipheral riniv 20a of the shell is flared outwardly and a protecting flange" 25 overlies the rim to prevent material passing around the smooth outer surface of the shell from being displaced onto the support shaft and possibly jamming the rotatable portions of the heat exchange device.

rlhe outer periphery of the'outwardly extending portion of the hollow shaft 28 is engaged by suitable rotatable support means, such as spaced ball bearing rings 34, 36 which are located in an annular bearing chamber 37 of the casing and serve to support the shaft and shell in ca'ntilevered position for high-speed axial rotation. The bearing chamber 37 is provided with suitable lubricating fluid for the bearings and end seals 38, 39 are Provided to prevent the escape of the lubricating fluid from the chamber 37 along the shaft 28 during rotation.

The shaft and shell are rotated by suitable drive means, such as an electric motor, not shown, which is drivingly connected to the end portion 28b of the shaft by an endless flexible element, such as a belt 40` (FIGURE l), which frictionally engages the peripheral surface of a drive coupling 41 keyed to the end portion of the shaft.

Means are provided for circulating a heating fluid, such as'steam, through the heating chamber 26 of the heat exchange device during its rotation and includes nonrotatable inner and outer axially'aligned fluid conduits 50,v 52 which extend through the hollow shaft 28 on the axis' of rotation A of the shaft 28 and outer shell 20. Erl'd portions 50a, 52a of the conduits 50, 52 extend beyond the adjacent end of the hollow shaft 28 and cornmunicate with the heating chamber 26, while the opposite ends 50b, 52b of the conduits extend into passages 53, 54 of a manifold block 55 mounted on the end of the fixed casing 12. The passages 53, 54 are provided with ring sealmembers 56, 57 which sealably engage the ends of the conduits to permit their`longitudinal movement in the passages, for a purpose which will be explained.

Steam is supplied to the heat exchange device by a fluid inlet line 58 which is connected to a steam supply source, not shown, and communicates with the manifold passage 53 and inner conduit 50. Condensed vapor is removed from the heat exchange device by a removal line 59 which communicates with manifold passage 54 and the outer conduit 52.

To facilitate circulation of the steam through the heating chamber 26 and provide for eflicient removal of conderised vapor `from the chamber, the heat exchange device 10.;i`s provided with a generally cylindrical closure cap 60` which is located in the heating chamber 26 and is removably attached to-the inner face of end wall 24 by bolts 61, one of which is shown, for rotation with the outer shell during operation of the device. The cylindrical outer wall 62 of the cap 60 is of stepped construction and the cap is positioned concentric with the axis of rotation A in surrounding, spaced relation to the end portions 5041,'52a of the inlet and outlet conduits 50, 52.

The closure cap 60 is provided with a condensate collec'tion pipe 63 which extends radially outwardly from the wall'62 and terminates closely adjacent the inner face of the outer shell 20. A first portion of the cap adjacent theend wall 24 defines a vapor condensate collection compartment 64 which connects the outer axially-aligned conduit 52 with the pipe 63 and a portion of the heating chamber 26 adjacent the end wall 25. Condensed vapor which accumulates on the inner face of the shell due to centrifugal force created during rotation of the shell is picked up bythe pipe 63 and passes into the collection compartment 64 where it is removed through radially disposed opening 65 in the outer conduit 52.

To permit the introduction of steam into the heating chamber 26 from the inner conduit 50, the outer end of the closure cap has an axially-aligned opening 60a, and a second, inwardly stepped portion of the cap adjacent the opening defines an incoming heating fluid passageway 66 connecting the open end of the inner, inlet conduit 50 with a portion of the heating chamber 26 remote from the end wall 24. AS can be seen, the relative positions oflthe heating fluid inlet opening 60a and the outer end of the condensate pipe 63 in the heating chamber facilitates the distribution and circulation of the heating fluid throughout the chamber prior to its removal from the chamber 'through thel outer outlet conduit 52.

The improved sealing means' of the present invention generally indicated at 70, is disposed between the end portions 50a, 52a ofthe non-rotatable conduits 50, 52 communicating with the heating chamber 26 and the adjacent rotatable portions of the heat exchange device 10 and serves to seal the heating chamber against loss of heating fluid and facilitate circulation of the heating fluid therethrough. The sealing means comprises a first non-rotatable sealing element 71 which is suitably secured to and surrounds the ends of the conduits 50, 52, and rotatable second-and third sealing elements72, 73 which-are positioned at opposite ends of the first sealing element along the axis of rotation A and in surrounding relation to the axis. Sealing element 72 is removably secured in a recess in the end of the hollow support shaft 28 for rotation `with the shaft and has a central opening through which the conduits 50, 52 pass. The third sealing element 73 is removably supported in a stepped portion of the closure cap 60 for rotation with the cap, and it also has a central opening therethrough to permit communication of the open end of the inner fluid conduit 50 with the fluid inlet passageway 66.

The sealing element 71 may be of suitable construction, such as chrome-plated steel, and it cooperates with the ywalls of the inner conduit 50 to effectively close off the extreme end of the outer conduit 52, while permitting unrestricted communication of conduit 52 with the condensate collection compartment 64 through a radially disposed opening 71a in the sidewall of the sealing element 70 which is aligned with the radial opening 65 in conduit 52.

As shown in FIGURE 3, the opposite end surfaces 81, 82 of the first sealing element 71 are convex and are disposed generally perpendicular to the axis of rotation A of the heat exchange device. The second and third sealing elements 72, 73, `which may be of graphite composition, have correspondingly concave sealing surfaces 83, 84 which frictionally engage the respective convex surfaces 81, 82 of the first sealing element and move relative thereto during rotation of the shaft and shell. All portions of the frictionally-engaging, relatively movable sealing surfaces 81484 are substantially equidistant from a common center C located on the axis of rotation to facilitate sealing engagement of the surfaces in the event that the non-rotatable conduits 50, 52 'become disaligned from the axis of rotation A, or in the event that the rotat able portions of the heat exchange device tend to oscillate during high-speed rotation. Additionally, by locating the sealing surfaces of the elements generally perpendicular to the axis of rotation, as shown, the frictional wear of the surfaces due to forces exerted in a direction generally perpendicular to the axis of rotation is minimized.

To provide for positive engagement of the relatively movably sealing surfaces 81-84 during rotation, means are provided for biasing the surfaces vinto engagement. As previously described, the ends S0b, 52b of the nonrotatable conduits are longitudinal movable in the passages of the manifold block and thus permit longitudinal movement of the conduits through the hollow shaft and shell. A resilient compression spring 85 in the fluid passageway 66 between the outer end of the closure cap and thel rear portion of the third sealing element 73 urges the third and first sealing elements 71, 73 along the axis of rotation A in the direction of the second sealing element 72 to ,maintainl the sealing surfaces in positive frictional engagement during rotation.

To prevent rotation of the first sealing element and conduits S0, 52 due to frictional engagement of the seal. ing surfaces of the sealing elements, the end portion of the outer conduit 52 is securely gripped by a ring member` 86 :which is keyed by a pin 87 to the end Wall of the fixed casing 12 to prevent rotation of the conduits 50, 52 'while permitting their biasing displacement along the axis 0f rotation A.

To facilitate insulation of the support bearings and Ilubricant from the heating fluid conduits 50, 52, the longitudinal opening of the hollow support -shaft 28 is enlarged in the outwardly extending portion of the shaft adjacent the bearings to provide an insulating air space 90 between the fluid conduits and the bearing chamber which effectively absorbs a large portion of the heat emitted by the steam in the fluid conduits.

To facilitate replacement of the removable sealing elements 72, 73 when they become suiciently worn, the end wall 22 of the outer shell may be removed from the shell by releasing bolts 91 to permit access to the interior of the heating chamber 26. The closure cap 60 may be removed frorn the end ywall 24, ring member 86 loosened from the end of the outer conduit, and the inner and outer conduits withdrawn from the lhollow support shaft, thereby freeing the sealing elements 72, 73 for replacement. The sealing elements may fbe replaced entirely fromthe front of the heat exchange device `without necessitating the removal of the device from its supporting frame or the removal of a portion of the fixed support casing 12 from the device.

VIn operation of the heat exchange device, heating fluid, such as steam, is introduced, under pressure, through the fluid inlet line 58 to the manifold block and inner conduit 50. The steam from4 the conduit 50 passes through `the inlet passageway 66 of the closure cap and is discharged into the heating chamber 26. During rotation of .the shell 20, material passing about its peripheral surface is effectively heated by heat transfer through the cylindrical wall of the shell. The condensed steam accumulating on the inner face of the cylindrical `wall of the shell is picked up by the rotating condensate pipe 63 and passes into the condensate collection compartment Where it is removed from the heating chamber of the roll by way of conduit 52 and condensate return line 59.

The frictionally-engaging, relatively-movable sealing surfaces 81, 84 of the respective non-rotatable first sealing element 71 and rotatable third sealing element 73 effectively seal the inlet conduit 50 and passageway 66 from `direct communication with the 4condensate collection compartment 64, while the frictionally-engaging, relatively-movable sealing surfaces 82, 83 of the first and second sealing elements 71, 72-effectively seal the heating chamber 64 from loss of heating fiuid along the nonrotata'ble axially-aligned conduits and hollow support shaft.

By positioning the relatively movable sealing surfaces closely adjacent the axis of rotation A, the size of the surfaces can be greatly diminished and the linear movement lbetween the same decreased to substantially reduce the lwear on the surface during rotation. Additionally, by maintaining all relatively movable sealing surfaces equidistant from a common center located on the axis of.rotation, the surfaces are maintained in sealing engagement at times when the non-rotatable conduits may become disaligned from the axis of rotation, or the rotatable elements of the heat exchange device tend to oscil- ,late or vibrate about the axis of rotation. By also locating the sealing surfaces generally perpendicular to the axis of rotation, the wear of the surface caused by forces acting onthe rotatable roll in a direction generally perpendicular to the axis of rotation is diminished.

In the drawings and specifications, there has been `set forth a preferred embodiment of the invention, and

adapted for high speed continuous treatment of material passing about its peripheral surface and comprising support means,

an elongate hollow shaft mounted by said support means for rotation relative thereto and having a cantilevered end portion extending outwardly from said support means,

a cylindrical outer shell having one end wall attached to said cantilevered end portion of said shaft for cantilever support and rotation of said shell therewith, said shell extending outwardly from said one end wall and having another end wall spaced outwardly from said cantilevered end portion for defining with said shell and said one end wall an internal fluid heating chamber,

stationary inner and outer axially-aligned fluid conlduits extending from adjacent the end of said hollow shaft remote from said cantilevered end portion `through said hollow shaft on the axis of rotation rthereof and outwardly beyond said support means and said one end wall for communicating with said heating chamber to permit the introduction and removal of heating fluid, and

sealing means disposed within said heating chamber between the outermost end portions of said conduits communicating with the heating chamber and the adjacent rotatable portions of said heat exchange device for sealing the heating chamber against loss of heating fiuid therefrom and for facilitating the circulation of heating fluid therethrough, said sealing means including frictionally-engaging, relativelymovable sealing surfaces positioned closely adjacent the axis of rotation of said heat exchange device to minimize frictional wear on said sealing surfaces during rotation.

2. Apparatus as defined in claim 1 wherein all portions of said sealing surfaces are substantially equidistant from a common center located on said axis of rotation to facilitate sealing engagement of said sealing surfaces in the event of disalignment of said non-rotatable conduits with said axis of rotation or oscillation of said rotatable portions of the heat exchange device during rotation.

3. Apparatus as defined in claim 2 wherein said sealing surfaces are disposed generally perpendicular to and surround said axis of rotation to minimize wear on the surfaces when forces are exerted on the rotating portions of the heat exchange device in a direction generally perpendicular to said axis of rotation.

4. Apparatus as defined in claim 2 wherein said end portions of said conduits extend into said chamber beyond the adjacent end of the support shaft; and wherein said sealing means includes a non-rotatable first sealing element surrounding said end portions of said conduits and a rotatable second sealing element removably secured to said adjacent end of the hollow support shaft, and said sealing elements having cooperating convex and concave surfaces disposed generally perpendicular to said axis of rotation and frictionally engaging each other to prevent loss of heating fluid from said heating chamber Vof the heat exchange device.

5.`V Apparatus as defined in claim 2 wherein said end portions of said conduits extend into said heating chamber beyond the adjacent end of the support shaft, and wherein said circulating means further includes a generally cylindrical closure cap removably attached to said one fend wall concentric with said axis of rotation and `in surrounding, spaced relation to said end portions of 6. Apparatus as defined in claim wherein said sealing means comprises a non-rotatable first sealing element surrounding the ends of said conduits, and rotatable second and third sealing elements positioned at opposite ends of said first sealing element along said axis of rotation and respectively removably secured to said end of the hollow support shaft and said closure cap between said first and second portions thereof, said first sealing element having convex opposite end surfaces disposed generally perpendicular to and closely surrounding said axis of rotation, and said second and third sealing elements having correspondingly concave surfaces frictionally engaging the convex surfaces of said rst sealing element, the frictionally-engaging surfaces of said first and second sealing elements preventing loss of heating fluid from said heating chamber, and frictionallyengaging surfaces of said first and third sealing elements preventing direct communication of said vapor condensate collection compartment with said inner conduit and said inlet fluid passageway to facilitate distribution of heating uid throughout said heating chamber of said heat exchanger device.

7. Apparatus as defined in claim 6 wherein said nonrotatable conduits are longitudinally movable in said heating chamber and hollow support shaft, and including means for biasing said frictionally-engaging sealing surfaces into engagement during rotation.

8. Apparatus as defined in claim 7 wherein said means for biasing said sealing surfaces into frictional engagement comprises a resilient spring positioned in said fluid 8 passageway between the outer end of said closure cap and said third sealing element and urging 'said third and first sealing elements along said axis of rotation in 'the direction of said second sealing element.

9. Apparatus as defined `in claim 1 wherein said means engaging the hollow shaft for rotatable support thereof comprises lubricated, spaced rotatable bearings' and wherein the longitudinalopening through Vsaid` hollow support shaft is enlarged `in the outwardly extending por; tion of the shaft adjacent said bearings to providean insulating air space between said axially-aligned ,fluid conduits and 4said bearings, thereby protectingthe bearings andklubricant from the high temperature heating fluid passing uthrough said uid conduits.

, References Citedy K UNITED STATES ILTENTSV 2,783,977 Seanor 285-134 Edwards 16S-89 ROBERT A. OLEARY, Primary Examiner T. W. STREULE, Assistant Examiner l U.s. c1. XR. 34-125