US2923227A

US2923227A - Fumes control system

Info

Publication number: US2923227A
Application number: US703727A
Authority: US
Inventors: Harry C Hawley
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-12-16
Filing date: 1957-12-16
Publication date: 1960-02-02
Anticipated expiration: 1977-02-02

Description

Feb. 2, 1960 Original Filed Oct. 1, 1952 H. C. HAWLEY FUMES CONTROL SYSTEM 3 Sheets-Sheet 1- IN V EN TOR.

Feb. 2, 1960 H. c. HAWLEY 2, 23,2

FUMES CONTROL SYSTEM Original Filed Oct. 1, 1952 3 Sheets-Sheet 2 5a i 5a IN VEN TOR. HARRY Cf 6642/5151;

ATY'OFNFK Feb. 2, 1960 H. c. HAWLEY FUMES CONTROL SYSTEM 3 Sheets-Sheet 3- Original Filed Oct. 1. 1952 .r 4 I, u

IN VEN TOR. HA1??? 6 Aka/m, BY.

May/.1

I A? T 01?? K United St t s at .9

F UMES CONTROL SYSTEM Harry C. Hawley, Wabash, Ind.

Continuation of application Serial No. 312,543, October 1,1952. This application December 16, 1957, Serial No. 703,727

12 Claims. (Cl. 98115) The present specification constitutes a continuation of my copending application, Serial Number 312,543, filed October 1, 1952 for a Fluid Handling Valving System which, in turn, is a continuation-in-part of my earlier-filed application Serial Number 240,729, filed August 7, 1951, for a Fluid Handling Valving System both now abandoned.

The present invention relates to a fumes control system which depends largely for its success upon a fluid handling valving means, and the invention is primarily concerned with the provision of means whereby communication will be effectively established and maintained between two relatively movable chambers, whlle communication with the atmosphere is prevented, regardless of the relative positions of the chambers. In addition to this primary object, it is a further object of the invention to provide means whereby communication may be always maintained between a source of vacuum and an element having a wide range of movement relative to said source. A further object of the invention is to provide novel means, associated with a movable chamber, for establishing and maintaining communication between the chamber and an elongated, stationary header, regardless of the position of said chamber in its path of movement longitudinally of said header.

A still further object of the invention is to provide a system whereby fumes arising from any source, as, for

instance, from a pool of molten metal in a pot or ladle which must, in ordinary usage, be transported from point to point, will be captured substantially at their point of origin and scavenged for discharge at a point Where their noxious character will be rendered innocuous.

Further objects of the invention will appear as the description proceeds.

To the accomplishment of the above and related objects, my invention may be embod ed in the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that change may be made in the specific constructions illustrated and described, so long as the scope of the appended claims is not violated.

Fig. 1 is a more or less diagrammatic view of an installation embodying my invention, the header and the movable chamber being shown in transverse section; 'Fig. 2 is a longitudinal section of the header and the chamber or carriage of Fig. 1, taken substantially on the Fig. 8 is a transverse section taken substantially on the line 8--8 of Fig. 6.

The valving means herein disclosed finds primary utility in the scavenging of fumes from a pouring ladle in a foundry, and it has been illustrated, and will be described, in that environment. It will be clear, however,

that such means will find substantial utility in other en-.

, in which the system is housed. Conventionally, fumes which rise from the ladle are allowed to emerge freely into the building, thus contaminating the atmosphere to an extent which is always disagreeable, and in some instances may actually be dangerous to the health of the workers concerned with the operations.

It is desirable, therefore, to provide a hood or canopy 16 over the ladle to receive such fumes, and to provide means for conducting those fumesto a point of discharge so arranged as to obviate those disadvantages. The canopy must, however, move with the ladle wherever the latter goes, if the system is to be effective, and the travel path of such ladle is conventionally so extensive as to malte the use of flexible conduit means, connecting the canopy with an exhaust fan or the like, entirely impractical.

According to my invention, therefore, I provide conduit means, which may be rigid, connecting an exhaust fan with the interior of an elongated header paralleling the trackway 14 throughout its length; and then 1 provide a movable, chamber-forming carriage, supported upon a second trackway following the first, connect that carriage chamber with the canopy through short conduit means which may' be rigid, though it is preferably flexible at least to a sliglit degree, and then provide means whereby the interior of the carnage chamber is maintained always in open communication with the interior of the header, while both the header and the chamber are always closed to the atmosphere except through the open mouth of the canopy.

As shown, then, the canopy 16 is supported from the carriage 12 through a conduit 17 from which conduit means 18 (shown as a flexible tube) leads to the chamber 19 formed in a carriage 20. Suitable supports 21 carry a stationary header 22 wh.ch parallels the course of the trackway 14 which, in the form of invention illustrated in Figs. 1 and 2, is substantially rectilinear. The header 22 is completely closed, except for one or more outlet conduits 24, leading to one or more. exhaust fans, and

except for the fact that its top wall 25 is formed with a slot 26 extending substantially from end to end of the header.

A web or strip 27, which may be formed of any flexible material substantially impervious to fluid flow therethrough, is arranged to span the slot 26 and tooverlap the lateral edges thereof on the outer surfaceof the wall 25. One end of said web is anchored as at 28 beyond the adjacent end of the slot 26, while the other end of said web extends beyond the opposite end of the slot, so that the web, when in contact with the wall 25, is capable of sealing the slot 26 completely. Preferably, a resilient, longitudinal tension is applied to said web to assist in maintaining proper sealing engagement between the web and the wall 25. In the illustrated embodiment of the invention, the anchor means 28 fixes the first-mentioned end of the web, while the opposite end 29 of the web runs past the opposite end of the slot 26, over a roller means 30, and, depending therefrom, supports a weight 31 which applies a resilient longitudinal tension to the entire length of the web. Alternatively, spring means might be attached to one orboth ends of the web; or the web might be formed of material such as rubber having a substantial inherent resiliency, in which case both ends of the web might be fixedly anchored.

The carriage is supported by wheels 32 arranged to run upon track elements which, in the illustrated form of the invention, are rails 33 carried by the header 22. The chamber 19 of the carriage 20 is closed except for its communication with the conduit 18, and except that its bottom is open to the wall of the header 22, and envelops a longitudinally short section of the web 27.

Thusjthe chamber 19 always registers with a short section of the slot 26, as the carriage 20 moves longitudinally of the header 22. Preferably, means such as one or more fingers 34 will provide a driving connection between the carriage 12 and the carriage 20 whereby the latter will follow themovements of the 'former.

Within the chamber 19, the carriage 20 supports a transverse member upon an axis removed a substantial distance from the plane of the wall 25; and the web 27 is led over and supported upon that surface of said transverse member remote from said wall 25, whereby the supported section of said web is held out of sealing relation withthe slot 26. Other transversemembers, spaced oppositely from said first-named member in the direction of length of the header, press upon the outer surface of the web ahead of, and behind, the first-named member to hold said web, at opposite ends of such supported section, in sealing relation with said slot. In the illustrated embodiment of the invention, and preferably, each of these three transverse members will be a roller.

Thus, a roller 35 is journal mounted inside the carriage upon trunnion means 36 suitably supported within the chamber 19, said roller spanning the width of the slot 26, and engaging the inner face of the web 27 to hold a section of said web, as shown in Fig. 2, out of sealing relation with the slot 26, the axis of rotation of said roller being substantially parallel with the header Wall 25 and transverse to the direction of length of the header 22. Ahead of the roller 35, a second roller 38, supported upon trunnion means 39, is mounted in the chamber 19 to span the width of the slot 26. As shown, the trunnion means 39 will be guided for vertical movement in retaining slots 40 suitably provided at opposite sides of the chamber 19, the axis of rotation of the roller 38 being substantially parallel with the axis of rotation of the roller 35. In the illustrated embodiment of the invention, gravity will cause the roller 38 to hold that portion of the web 27 engaged by said roller in close contact with the wall 25 and in sealing relation with the slot 26. A similar roller 41, having trunnion means 42 guided in similar slots 43 is arranged behind the roller 35 for a similar purpose.

It will be seen that the chamber 19 is closed to the atmosphere, but is always open to the interior of the header 22 through that section of the slot 26, within the confines of the chamber 19, which is held open by the engagement of the roller 35 with .the enveloped section of the web 27. Preferably, strips of felt or the like, 44 and 45, willbe carried at the lateral edges of the carriage 20 to bear on the wall 25, and

similar strips

46 and 47 may be carried at the forward and rearward edges of the carirage, whereby leakage of air'into the chamber 19 is minimized. These sealing strips may be secured in place in any suitable fashion as, for instance, by means of a ring 44 fastened within .the carriage by rivets and clamping the strips against the adjacent carriage walls. a

As the carriage 20 moves along the trackway 33 in unison with movement of thecarriage'12 along the trackv.4 way 14 that section of the web 27 currently within the chamber 19 will be lifted, by the roller 35, out of sealing relation with the slot 26; while the rollers 38 and 41 will act to limit the longitudinal extent of the lifted section of the web.

If desired, the gravitational effect upon the rollers 38 and 41 may be supplemented by springs acting downwardly on said rollers. It will be recognized, of course, that the pressure dilferential resulting from the evacuation of the header 22 will eifectively hold the web 27 in sealing relation with those portions of the slot 26 currently outside the confines of the chamber 19, and that the longitudinal tensile stress to which the web is subjected tends to prevent rumpling of said web as the carriage 20 moves therealong.

The structure thus far described is eminently satisfactory in use in a system in which the trackway 14, and hence the header 22, can be rectilinear. In some installations, however, the equivalent of the trackway 14 must be curved or sinuous, and in Figs. 3 and-4 I have illustrated a somewhat more complicated embodiment of my invention adapted for use in such installations.

Thus, where the header 50 must embody one or more curves, the slot 51 may be formed in that header wall 52 which is substantially parallel with the axis or axes of curvature of said header, and the trackway for the chamber-forming carriage will comprise two

rails

53 and 54 arranged in a common plane at opposite edges of said wall 52. 'In this form of the invention, means must be provided for retaining the slot-sealing web 57 against lateral movement relative to the slot, and I prefer to provide boundary flanges 55 and 56 on the

rails

53 and 54 to perform that function, as clearly shown in Fig. 3.

A carriage 58 is formed to provide a chamber 59 analogous to the chamber 19; and saidcarriage is supported from the trackway in a novel manner now to be described.

A hanger 60 rigid'with the carriage 58 provides a hearing 62 for the stem 63-of a bracket 64, whereby said bracket is oscillable, relative to the carriage, about the axis of said stem which lies in, or parallel to, the common plane of the track rails 53 and 54. An axle 65 traverses the bracket 64 upon an axis perpendicular to the stem axis, and mounts a grooved wheel 66 supported upon the rail 53. The bracket 64 further supports two

Wheels

67 and 68 upon axes parallel with the stern axis and equally and oppositely spaced from said common plane, said last-named wheels engaging opposite surfaces of said rail 53.

Registering with the hanger 60 but secured to the opposite side of the carriage is a second hanger 61 providing a bearing 69 for the stem 70 of a second bracket 71. Said bracket 71 may be identical with the bracket 64 but preferably will take the simplified form illustrated, having no equivalent of the wheel 66 and carrying

only wheels

72 and 73

equivalent to'the wheels

67 and 68 and cooperating with the rail 54 in a similar manner. Preferably, a rigid strap 74 will provide a mechanical connection between the bracket 64 and the bracket 71. Of course, a similar set of brackets and associated parts will be arranged at each end of the carriage 58.

Within the chamber 59 is arranged a roller 75 carried on trunnion means 76 supported in fixed bearings. Said roller is functionally equivalent in all respects to the roller 35 and acts upon the web 57 as the roller 35 acts on the web 27.

A roller 77 is carried on trunnion means 78 and is located ahead of the roller 75; while a similar roller 79 is carried on trunnion means 80 behind the roller 75. In this form of the invention, the trunnion means 78 is supported at the free end of a lever 81 swung from a pivot rod 82 traversing the chamber 59, and a coiled spring 83 is confined between a fixed abutment 84 in the carriage 58 anda seat 85 on the lever 81 to press the roller 77 resiliently toward the header wall 52. Similarly,

'the trunnion means 80 is supported at the free end'of a lever 86 swung from a pivot rod 87 traversing the chamber 59, and a coiled spring 88 acts on the lever 86 to press the roller 79 resiliently toward the header wall 52.

The action of this form of the invention is broadly equivalent to that of the form illustrated in Figs. 1 and 2, except that the carriage 58 is able readily to follow curves in the wall 52 and the

rails

53 and 54. The wheels 66, of course, support the carriage and tend to follow the curvature of the rail 53, while the wheel-supporting brackets turn about the axes of their stems 63 and 70 and the

wheels

67 and 68 and the

wheels

72 and 73 hold the carriage against lateral movement relative to said rails.

As said before, the last described embodiment of my invention is somewhat more complicated than the embodiment first described. While its use fulfills a need not satisfiable by the first embodiment, it, too, is somewhat limited in its application. For these reasons, I have illustrated and shall now describe, a further modification of my invention somewhat simplified and more universal in its application.

Referring now to Figs. 5 to 8 inclusive, the header 90, having a number of curved portions 91 therein, has the slot 92 formed in the upper wall 93 thereof. The slotsealing web 94 is shaped to conform to the contour of header 90 and is held against lateral displacement by the provision of longitudinally-extending guide flanges 95 and 96 upstanding from wall 93 and skirting the opposite rims of slot 92 as most clearly shown in Figs. 5 and 8. Flanges 95 and 96 are supported on the inner edges of horizontal plates 97 and 98 securely fixed to the upper wall 93 and extending laterally beyond the sides of the header 90, for a purpose later to become apparent.

The carriage 99 is formed to provide a chamber 100 analogous to the

chambers

19 and 59; and said carriage is supported on the header in a manner now to be described.

Within chamber 100, cross-headers 101 and 102 are supported on carriage 99 near the opposite ends of said chamber. Each cross-header supports a depending spud 103 having a bore 104 therein along an axis substantially perpendicular to wall 93 and lying substantially in the median plane of said carriage.

Journalled in each bore 104 is a king-pin 105 supporting a hub 106 having an axial bore 107 therethrough substantially normal to bore 104. A trunnion 103 is mounted in each bore 107 and has journalled on the ends thereof a pair of rollers 109 and .110. The spacing between the opposite ends of said rollers is substantially the distance between the inner surfaces of guide-flanges 95 and 96. The rollers at each end of the carriage are each disposed between the flanges 95 and 96 and as such act as wheels whereby carriage 99 is supported on header 90. Additionally, since the rollers 109 and 110 run on the outer surface of the web 94, they act to hold said web in sealing contact with header Wall 93.

For the purpose of holding that portion 111 of web 94 currently in registry with chamber 100, out of sealing engagement with slot 92, I provide a shaft 112 supported within chamber 100 upon suitable brackets carried by carriage 99, said shaft being spaced substantially from to the longitudinal length of header 90. Rollers 117 are so positioned on dolly 114 as to be laterally engaged by the inwardly facing surfaces of guide flanges 95 and 96.

carriage 99 enters a curved portiQn 91 of the header 90, 'the'mid-portion of the carriage will be shifted laterally relative to the header, its slot 92 and the web 94. Due to the coaction between wheels 117 and flange 96, the dolly 114, however, is compensatingly laterally shifted on shaft 112 to retain roller 113 axially in proper cooperative association with the web portion 111. Upon movement of carriage 99 from curved portion 91 to a straight portion of header 90, flange engages rollers 117 and again shifts roller 113 relative to the carriage so as to maintain it always in proper position relative to web portion 111.

Suitable gasket means 118 provides a substantially tight seal between the carriage skirt and the horizontal plates 97 and 98.

It will, of course, be apparent that a series of apertures, longitudinally spaced apart a distance less than the length of

chambers

19, 59 and might be formed in the

headers

22, 40 or 90, in place of

continuous slots

26, 51 or 92, and it is intended that such an arrangement shall be included in the expression a longitudinally-extending slot, or the like.

I claim as my invention:

1. In a fume-controlling system, a hood adapted to be mounted in overlying relation to the open mouth of a container for a fuming liquid, an elongated header having one wall thereof formed to provide a longitudinally-extending slot, fluid-evacuating means connected to the interior of said header, a flexible, substantially fluid-impervious strip disposed exteriorly of said one header wall and overlying and normally closing said slot, a carriage, trackway means supporting said carriage for longitudinal movement relative to said header, said carriage having walls extending away from said strip, said walls being joined by a common outer wall, the edges ofsaid first-named carriage walls adjacent said strip being provided with sealing means extending along said wall edges and engaging said one wall of said header to define a chamber closed to the atmosphere, said chamber registering with a longitudinally-short section of said slot and enveloping therein a corresponding section of said strip, strip-supporting means, means carried by said carriage and mounting said strip-supporting means within said chamber upon an axis substantially spaced from said one header wall and extending transversely relative to the length of said header, said strip-supporting means engaging that surface of said corresponding section of said strip which faces said one header wall to support the engaged section of said strip in spaced relation to said slot, strip-engaging means, means carried by said carriage and mounting said strip-engaging means within said chamber upon axes ahead of and behind said stripsupporting means and extending transversely relative to the length of said header, said strip-engaging means bearing against the opposite surface of said strip to press the same into intimate contact, within said chamber, with said one header wall in sealing relation with said slot, conduit means connecting the interior of said chamber with the interior of said hood, and means enforcing movement of said carriage longitudinally of said header to follow movement of said hood with said container.

2. A fume controlling system for a brass foundry or the like including a mobile ladle for transporting fuming moltenmetal from a furnace to a plurality of spaced molds, a hood, means for connecting said hood in overlying relation to the open mouth of such a ladle, an elongated header having one wall thereof formed to provide a longitudinally-extending slot, fluid-evacuating means connected to the interior of said header, a flexible,

substantially fluid-impervious strip disposed exteriorly of said one header wall and overlying and normally closing said slot, a carriage, trackway means supporting said carriage for longitudinal movement relative to said header, said carriage having walls extending away from said strip, said walls being joined by a common outer wall, the edges of said first-named carriage walls adjaenemas? cent said strip :beingprovided with-.sealingineans extending along said wall edges and engaging said one wall of said header to definea chamber. closed to the atmos phere, said chamber registering with a longitudinallyshort section of said slot and enveloping therein a corresponding section of said strip, strip-supporting means, means carried by said carriage and mounting said stripsupporting means within said chamber upon an axis substantially spaced from said .one header wall and extending transversely relative to the length of said header,

said strip-supporting means engaging that surface of said corresponding section of said strip which faces said one header wall to support the engaged section of said strip in spaced relation to said slot, strip-engaging means, means carried by said carriage and supporting said strip-engaging means within said chamber upon axes ahead of and behind said strip-supporting means and extending transversely relative to the length of said header, said strip-engaging means bearing against the opposite surface of said strip to press the same into intimate contact, within said chamber, with said one header wall in sealing relation with said slot, said strip engaging means being located immediately adjacent two of said carriage walls, conduit means connecting the interior of said'chamber with the interior of said hood, and means "enforcing movement of said carriage longitudinally 'of said header to follow movement of saidhood with said ladle.

3.1n a system of the class described, an elongated header provided with longitudinally-extending slot means opening through one wall thereof, means for continuously evacuating said header, trackway means supported from and following the length of said header, a carriage supported and guided upon said trackway means for longitudinal travel relative to said header, said carriage having'walls extending away from said header, said walls being joined by a common outer wall and defining an open side opposite said common wall presented to said one header wall, said carriage thus being formed to define, with said header wall, a chamber closed to the atmosphere, gasket means carried by said carriage walls and engaging said header wall to provide a fluid seal for said chamber, a flexible, substantially fluid-impervious strip exteriorly arranged upon said one header wall to span said slot means, having a longitudinally-short sec- 7 tion enveloped Within said chamber and having a fluidsealing relation with said slot means from end to end thereof except within said chamber, strip-supporting means, means carried by said carriage and mounting said strip-supporting means wholly within said chamber upon an axis transverse with respect to the length of said header and significantly spaced from said header wall, said strip-supporting means engaging that surface of the strip section currently enveloped within said chamber which surface-faces said header wall to hold a portion of such enveloped section out of sealing relation with said slot means, two strip-engaging means, means carried by said carriage and mounting said respective strip-engaging means wholly within said chamber upon axes substantially parallel with, and oppositely spaced in the direction of header length from, the axis of said strip-supporting means, each of said strip-engaging means bearing upon the opposite surface of said strip section within said chamber, to press said strip into engagement means supporting said carriage on said upper wall for longitudinal mo'vement relative to saidheader, said carriage having walls with sealing means extending along the lower edges of said walls engaging said upper wall of said header to define a chamber registering with a longitudinally-short section of said slot and receiving therein the corresponding section of said web, duct means connecting said chamber with a source of fluid, a Web-supporting roller, means supporting said web-supporting roller on said carriage within said chamber upon an axis substantially spaced from said one header wall and extending transversely relative to the length of said header, said web-supporting roller engaging a lower surface of said corresponding section of said web to support the engaged section of said Web in spaced relation to said slot, web-engaging rollers, means supporting said web-engaging rollers on said carriage within said chamber, said web-engaging'rollers being located respectively behind and ahead of said web-supporting roller and engaging the upper surface of said web to press the same into intimate contact with said one header wall in sealing relation with said slot, said web-engaging rollers being located immediately adjacent two of said carriage walls, said carriage being internally formed to providea plurality of slots elongated in a direction substantially normal to said one header wall, and each of said means supporting said web-engaging rollers comprising a trunnion having its ends mounted in a mating pair ofsaid slots.

5. In a device of the class described, an elongated header having one wall thereof formed to provide a longitudinally-extending slot, duct means connecting said header with fluid-evacuating means, web means, means supporting said web means on the exterior of said one header wall with said web means overlying and normally closing said slot, a carriage, means supporting said carriage for longitudinal movement relative to said header, said carriage being formed to define a chamber registering with a longitudinally-short section of said slot and receiving therein the corresponding section of said web means, duct means connecting said chamber with a source of fluid, web-supporting means, means supporting said web-supporting means on said carriage within said chamber upon an axis substantially spaced from said one header wall and extending transversely relative to the length of said header, said web-supporting means engaging that surface of said corresponding section of said web means adjacent said one header wall to support the engaged section of said web means in spaced relation to 'said slot, web-engaging means, means supporting said web-engaging means on said carriage within said chamber, said web-engaging means being located respectively behind and ahead of said web-supporting means and engaging the opposite surface of said web means to press the same into intimate contact with said one header wall in sealing relation with said slot, each of said means supporting said web-engaging means being a trunnion, said device further including a lever supporting each trunnion, and pivot means for each lever supported on said carriage, each pivot means supporting its lever adjacent one end to swing in a plane substantially perpendicular'to said one header wall.

6. The device of claim 5 including spring means:acting on said levers and resiliently urging the free ends of said levers toward said one header'wall.

7. In a device of the class described, an elongated header having one wall thereof formed to provide a longitudinally-extending slot, duct means connecting said header with fluid-evacuating means, web means, means supporting said web means on the exterior of said one header wall with said web means overlying and normally closing said slot, a carriage, means supporting said carriage for longitudinal movement relative to said header, said carriage being formed to define a chamber registering with a longitudinally-short section of said slot and receiving therein the corresponding section of said web means, d'uct means connecting said chamber with a source of fluid, web-supporting means, means supporting said web-supporting means on said carriage within said chamber upon an axis substantially spaced from said one header wall and extending transversely relative to the length of said header, said web-supporting means engaging that surface of said corresponding section of said web means adjacent said one header wall to support the engaged section of said web means in spaced relation to said slot, web-engaging means, means supporting said web-engaging means on said carriage within said chamber, said web-engaging means being located respectively behind and ahead of said web-supporting means and engaging the opposite surface of said web means to press the same into intimate contact with said one header wall in sealing relation with said slot, said web-engaging means being rollers supported upon axes spaced longitudinally relative to said header wall, and extending transversely relative to the length of said header, and spring means resiliently urging said rollers toward said one header wall.

' 8. In a system of the class described, a trackway, a

- ladle for fuming molten metal supported from said trackway for transportation therealong, a hood, means for connecting said hood in overlying relation to the open mouth of said ladle for travel with said ladle, an elongated header paralleling said trackway, said header beingprovided with longitudinally-extending slot means in one Wall thereof, a carriage trackway means supporting said carriage for longitudinal movement along said header, said carriage having walls extending away from said one header wall, said walls being joined by a common outer wall to define, with said one header wall, a chamber enveloping a longitudinally-short section of said slot means, gasket means extending along the edges of said carriage walls adjacent said one header wall and cooperating with said header to seal said chamber against fluid flow thereinto from the circumambient atmosphere, a flexible, substantially fluid-impervious strip exteriorly disposed against said one header wall and spanning said slot means in sealing relation thereto except within said chamber, strip-supporting means, means in said carriage and mounting said strip-supporting means wholly within said chamber, said strip-supporting means supporting a portion of the chamber-enveloped section of said strip out of sealing association with the chamber-enveloped section of said slot means, strip-engaging means, means in said carriage and supporting said strip-engaging means wholly within said chamber, said strip-engaging means bearing upon the chamber-enveloped section of said strip, at separate points oppositely longitudinally spaced from said strip-supporting means to press said strip into slotsealing engagement with said one header wall, conduit means connecting said hood with the interior of said chamber, and means for continuously evacuating said header, said chamber being constrained to follow the travel of said ladle along said trackway.

9. In a device of the class described, an elongated header having one wall thereof formed to provide a longitudinally-extending slot, a pair of guide flanges upstanding from said one header wall substantially parallel with the lips of said slot and spaced oppositely outward therefrom, duct means connecting said header with fluidevacuating means, web means, means supporting said web means on the exterior of said one header wall with said web means overlying and normally closing said slot, a carriage, means supporting said carriage for longitudinal movement relative to said header, said carriage being formed to define a chamber registering with a longitudinally-short section of said slot and receiving therein the corresponding section of said web means, duct means connecting said chamber with a source of fluid, websupporting means, a shaft supporting said web-supporting means on said carriage within said chamber upon an substantially spaced from said one header wall and p "extending transversely relative to the length cf said head- 'er, said web-supporting means engaging that surface of said corresponding section of said web means adjacent said one header wall to support the engaged section of said web means in spaced relation to said slot, web-engaging means, and means supporting said web-engaging means on said carriage within said chamber, said webengaging means being located respectively behind and ahead of said web-supporting means and engaging the opposite surface of said web means to press the same into intimate contact with said one header wall in sealing relation with said slot, and said web means and said web-engaging means having transverse dimensions substantially equal to the spacing between said guide flanges and engaging said one header wall between said guide flanges, said web-supporting means comprising an axially shiftable roller journalled upon said shaft for rotation about the axis thereof, said'device further comprising a dolly including frame means supported from said shaft at opposite ends of said roller and shiftable axially upon said shaft, and guide means supported from said frame means and engaging the inner surface of said guide flanges, said dolly having cooperative engagement with said roller and being axially shiftable by said guide means to so shift said roller in conformity with. lateral deviations of said guide flanges.

10. In a device of the class described, an elongated header having one wall thereof formed to provide a longitudinally-extending slot, a pair of guide flanges upstanding from said one header wall substantially parallel with the lips of said slot and spaced oppositely outward therefrom, duct means connecting said header with fluidevacuating means, web means, means supporting said web means on the exterior of said one header wall with said web means overlying and normally closing said slot, a carriage, means supporting said carriage for longitudinal movement relative to said header, said carriage being formed to define a chamber registering with a longitudinally-short section of said slot and receiving therein the corresponding section of said web means, duct means connecting said chamber with a source of fluid, web-supporting means, means supporting said Web-sup porting means on said carriage within said chamber upon and axis substantially spaced from said header wall and extending transversely relative to the length of said header, said web-supporting means engaging that surface of said corresponding section of said web means adjacent said one header wall to support the engaged section of said web means in spaced relation to said slot, web-engaging means, and means supporting said web-engaging means on said carriage within said chamber, said webengaging means being located respectively behind and ahead of said web-supporting means and engaging the opposite surface of said web means to press the same into intimate contact with said one header wall in sealing relation with said slot, and said web means and said webengaging means having transverse dimensions substantially equal to the spacing between said guide flanges and engaging said one header wall between said guide flanges, each of said means supporting said web-engaging means comprising a trunnion, king-pin means oscillably supported on said carriage upon spaced axes substantially normal to said one header wall and each supporting one of said trunnions in a plane substantially parallel to said one header wall, said web-engaging means each comprising rollers journalled upon said trunnions and axially confined between said guide flanges.

11. In combination, an elongated header, means for contiuously evacuating said header, said header being provided with an elongated slot opening through a wall thereof, a flexible web overlying said slot externally of said header and normally sealing said slot against fluid movement therethrough, a carriage, track means extending longitudinally of, and supported from, said header and supporting said carriage for longitudinal movement spasm? ill .relative :to said header, said carriage having walls I extending-away from said web, said walls being joined by a common outer wall, the edges 'of said :first-named carriage walls adjacentsaid -web being provided with sealing means extending along said wall edges and-engaging saidone wall of'said header to define a chamber enveloping -a longitudinally-short section of saidWeb, web-supporting means within said chamber engaging the envelope'dweb section to holdthesame spaced from said header Wall,- means 'insaid carriage mounting said websupportingmeans, web-engaging means-within said chamber engaging the enveloped web 'section at separate points longitudinally oppositely spaced ,from said websupporting means toipress said web firmlyagainst said header wall, means in said carriage mounting said webengaging means,- a hood, conduitmeans connecting said hood with the interior of said chamber, -a mobile vessel .for'fuming-liquid, and means for connecting said hood against fluid movement therethrough, a carriage, track means extending longitudinally .of said header and sup- ,porting said carriage for longitudinal movement relative to said header, said track means including opposite rails lying substantially in a'common plane at opposite edges of said slotted wall, a bracket on said carriage mounted for oscillation relative to said carriage about an axis lying substantially in said common plane, a wheel journalled in said bracket on an axis substantially perpendicular to said axis of oscillation, said wheel running on one of said rails to support said carriage therefrom, a pair of wheels journalled in said bracket on axes substantially parallel with said common plane to engage opposed surfaces of said one rail, said carriage defining a chamber enveloping a short section of said web, means within said chamber engaging the enveloped web section to hold the same spaced from said header wall, and means for continuously evacuatingsaid header.

References Cited in the file of this patent UNITED STATES PATENTS 2,495,376 Lusk Jan. 24, 1950 2,496,209 Homing Jan. 31, 1950 2,693,749 Houdek Nov. 9, 1954 2,810,336 Sheifer Oct. 22, 1957 FOREIGN PATENTS 19,838 Great Britain Oct. 2, 1905 462,135 Germany July 5, 1928 UNITED STATES PATENT IEFICE CERTIFICATE OF CORRICTION Patent No. 2923,22? February 2, 1960 Herry C. Hawley It is hereby certifiefl that error ippears in the printed Specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1O line 44, claim l0 for "and axis" read an axis same line, after "said" insert one -g line 69 claim 11, for "contiuous 13'! read continuously Signed and sealed this 5th day of Tuly 1960.

I'YCS'EAL) KARL H, AXLINE ROBERT C. WATSON Attesting Officer Comissioner of Patents