US2901132A - Blast furnace seal - Google Patents

Description

Aug. 25, 1959 RUTH 2,901,132

BLAST FURNACE SEAL.

Filed March 14, 1958 5 Sheets-Sheet 1 2o ,7 I6 0 D' ii I I y i 9 as 22 s I: 1: 2! t! as 4 55 E IN V EN TOR. HELMER 4 RUTH ATTORNEYS Aug. 25, 1959 H. A. RUTH 2,901,132

BLAST FURNACE SEAL Filed March 14, 1958 s Sheets-Sheet 2 INVENTOR. HELMER A. Rum

A TTORIYEYS Aug. 25, 1959 H. A. RUTH BLAST FURNACE SEAL 5 Sheets-Sheet 3 Filed March 14, 1958 ATTORNEYS H. A. RUTH BLAST FURNACE SEAL Aug. 25, 1959 5 Sheets-Sheet 4 Filed March 14, 1958 Hsmsn A, Earn x 3 mm ATTORNEYS Aug. 25, 1959 H. A. RUTH BLAST FURNACE SEAL 5 Sheets-Sheet 5 Filed March 14, 1958 INVENTOR. i .ll] l-lsuwm A. H E v flax: x/ /Z ATTORNEYS United States Patent BLAST FURNACE SEAL.

Hehner Adolph. Ruth, Duluth, Minn, assignpr to Inter,-

lake Iron Corporation, Cleveland, Ohio, a corporation of New York Application March 14,1958, Serial. N0, 721,37

Claims. (Cl. 214-37.)

This invention relates tov blast. furnaces-and more particularly to. sealing means for rotating distributors located at the top of such. furnaces.

Blast furnaces have been provided; with a rotatable upper hopper or distributorwhich. projectsv at its. lower end downwardly into a lower hopper of. the. furnace. Since the lower hopper does not rotate, anrannular space will occur between the outside wall: of the. distributor and the upper end of the furnace shaft wall through which. the. rotating distributor projects. During operation of the furnace, there isa pressure differential between the lower hopper andthe outside atmosphere, which causes the. toxic, dust laden furnace gases to leak or flow. through the annular space between the distributor and the furnace shaft walls (and thence to the outside atmosphere) in the absence of sealing means therebetween. Such gas leakage constitutes a loss in efficiency of operation and serious hazard to personnel atthetop ofthe furnace.-

In many types. of furnace construction, the gasescape path. between. the. distributorand the top of the furnace shaft follows a. structurally formed labyrinth or sinuous path, the inner end of which is exposed to the interiorof the. furnace, with theouter end thereof being sealed by some type; of sealing. means.

Although many types ofi gas sealingmeans have been used: toprevent the escapeof furnace gases, they have not been. entirely. satisfactory, particularly when the furnaceis operatingunder ahightop pressure. Here-tofore, because of the. relativemovementbetween the distributor and the furnace. shaft, the. packing or sealing means. therebetween. has been subjected to excessive wear, which reduced its elfectiyeness. A- contributingfactor to such excessiuewearis thefact that the distributor often rotates otf center from. its verticalaxis. Additionally; such olfi center rotation, in many instances, caused thesealing' means to fracture.

An. object. of the invention is to provide an effective seal between. the. distributorand the blast furnace shaft which: is relatively. free-of friction andis subject to a minimum of wear and maintenance.

A further object of the invention is to provide a seal between. the distributor and the blastfurnace shaft which is; particularly. effective when the distributor rotates off center from its vertical axis.

A. further object of the invention isv to provide a seal which may be adjusted to -maintain packing-pressure when the distributor. rotates off center from its vertical axis, thereby reducing maintenance requirements and grease leakage toa minimum.

Briefly, the foregoing objects are accomplished by the provision of; a resilient seal ringdisposed near the outer end: of thesinuous gasescape path between the distributor hopper and. the topof'thezfurnace.shaft. The seal may be in the formiof a flat, annular shaped member, the-outer periphery of; which; may be clamped; in. a substantially ha izqnta1 pl ne a spa edt intervals. to the furnace shaft ro t s We-1L iunss quir s-port on; if- 119 seal may be resiliently retained, against a suitable horizontally disposedflange member securedto and forming apart of the outer, vertically extending, wall portion of the dis tributor hopper wall. Such inner portion of the seal may be resiliently retained against the flange member by any suitable means. as, for example, conventional coil springs having means for adjusting the bias thereof. With this construction, an adjustable seal is provided Which-main tains a tight engagement with the flange on the/distributor wall: even when the distributor rotates off center with respect to its vertical axis.

Other objects and advantages of the invention will be apparent from the following description taken in con!- junctionwith the drawings in which:

Fig. l is a. vertical sectional viewof the charging poi=- tionand the distributor at thetop of a. blast furnace and showinga seal between. the distributor and the furnace shaftwall constructed in accordance with the invention;

Fig. 2 is a fragmentary enlarged sectional view of a portion of the seal structure shown in Fig. 1-;

Fig. 3 is anenlargedhorizontal sectional view taken along the line 3-3 of Fig. 1 and showing, in exploded View, the relative position of aportion of the metal wall segments, the spring holdingouter flange member and the-flexible seal member of the seal assembly;

Figs. 4 and 5- are enlarged fragmentary perspective views showing the respective separated mated extremities of the metab wall segments shown in the exploded View portion of- Fig; 3;

Fig. 6 is an enlarged; fragment-aryper-spect-ive view' of the outer spring holding flange membershown in the exploded view portion of Fig. 3-;

Fig. 7 is a reduced. topplan view of-onesegment of the seal: base member shown in Fig. 2;

Fig. Sis a sectional view taken alongthe line 8 -Sof Fig. 7;

Fig. 9 is a view taken along the line 9-9-o f Fig 7;

Fig. 10 is. a fragmentary enlargedsectional view of the spring portion of the seal structure shown in Fig. 2.

Referring to Fig. 1, there is shown the annulartop portion of a blast furnace B- in the formof a lower bell hopper 10; which is. open at the top to receive an upper cylindrical distributor or small bell hopper 12* into which a skip car orother loadingdevice may dump its charge in a manner well known in the art: The hopper 12i's in the form of a vertically disposed cylindrical chute open at the top and bottom with the bottom being closed; by a vertically reciprocable small bell 14; In practice, the small bell 14 is carriedat the lower end of a tube 15 through-whicha suitable bell rod 16 may pass for support.- ing a large bell- (not shown) in the hopper 10 i To providefor uniform distribution of the charge when it is dropped into the furnace, the hopper i2 is rotatably supported in the open top end of the hopper 10' by providing it with an annular flange 17, which carries the upper and. lower annular tracks 1-8 and-1'9 respectively. These tracks are guided respectively by the upper holddown rollers 2th and the lower supporting rollers 21', each of which is journaled in bearings mounted on spaced outwardly extending supporting brackets 22, which. are

carriedby the wallportion; 23. The flange 1'7" carries a ring gear 25-on itsper-ipherv which meshes with a pinion gear 26 that is keyed to the shaft of a suitable driving means 28. The driving means 28 may be secured to the bracket 29-,- Which extends outwardly from the Wall portion- 23.

The upper portionofthe hopper Iii-supports an annular wall member 32, which is spaced radially inwardly from the. vertically extending wall portion 23- ofthe hopper 10 to. form an. annular gap ortrough 3-3 'therebetween. In. order to prpvidefor. a labyrinth or sinuousescape path forthe dust; laden. furnaces. gases flowingfrorir the interior of the hopper 10, a downwardly extending annular sleeve member 35 is suitably secured to the annular hopper flange 17 and is positioned between the member 32 and the wall 23. The sleeve 35 depends downwardly and extends into the annular trough 33 formed at the top of the hopper 10. Accordingly, the furnace gas is required to flow in a sinuous path by passing upwardly from the interior of the hopper 10, then between the hopper 12 and the vertically extending hopper wall mem- 'ber 32, around the top of the wall member 32, then downwardly between the wall member 32 and the sleeve member 35, around the lower end of the sleeve member 35 and upwardly along the outer side of the sleeve 35 to the gas sealing means indicated in general at S.

Referring to Fig. 2, the seal S is shown as being disposed within the connecting flanges or ears 39 of the annular support ring or seal base member M. The member M may be formed of a plurality of segments of the type shown in Fig. 7. Each segment comprises a body portion 41 (substantially rectangular in cross section as shown in Fig. 8) having the ears 39 on each end thereof by means of which the segments may be bolted or otherwise connected together in end-to-end relation to form the base member M. The upper end of each ear 39 carries a pad or shoulder 42 (Figs. 2 and 9) which operates to support the outer cylindrical wall 23 (Fig. 2) together with the mechanism carried thereby. The base body portion 41 may be bolted or otherwise con nected as at 36, to the flange 46 formed on the lower end of the wall member 32. Thus the seal base member M forms a rigid connection between the wall portion 23 and the top of the large hopper 10. Additionally, this construction provides open spaces between the ears 39 to enable replacement of the seal S or any part thereof when necessary. Said spaces enable also the intro duction of lubricant through the grease fitting 63 and the grease inlet 68. Disposed on the base member body portion 41 is a partially U-shaped annular channel member 48 on which the seal S is mounted.

The seal S includes a resilient ring or seal 50, the outer portion of which is clamped between the upper and lower circular segments or members 52 and 56, respectively, by means of the bolts 47, with this entire assembly being mounted on the channel member 48 by the bolts 49 as shown in Fig. 2. The seal 50 may be formed in two semi-circular halves which are placed in position around the furnace, after which the two joints of the halves may be vulcanized to form a one-piece circular seal. Disposed on the inner portion of the seal 50 is a spring plate 62, which may be formed of a plurality of individual segments as shown, for example, in Fig. 3 wherein the plate 62 comprises ten segments cemented to the seal 50. Initially, the segments may be cemented to each of the above-mentioned semi-circular halves of the seal 50, after which the halves are placed in position around the furnace and the joints vulcanized together. The seal 50 may be made of any suitable rubber-like, resilient material, such as Goodyear Chemigum packing. The inner bottom portion of the seal 50 sealingly engages the face plate or member 58 (Fig. 2), which is secured to the revolving distributor sleeve member 35. The plate 58 may be secured to the sleeve 35 by any suitable means as, for example, the set screws 59.

To enable adjustment of the engagement pressure between the seal 50 and the plate 58, the seal is provided with a pressure adjusting means including a coil spring 60 (Fig. and a plate 62, which bear downwardly against the upper side of the inner portion of the seal 50. Each member 52 may be provided with inwardly extending projections 64 spaced circumferentially at predetermined intervals as shown in Fig. 3. Each projection 64 contains a threaded aperture 65 for receiving a threaded bolt 66 (Fig. 10) therethrough. The bolt 66 is threaded through the aperture 65 and engages the dishshaped spring seat or disk 67, which is biased upwardly 4 by the coil spring 60 which is always under compression between the disk 67 and the plate 62. The disk 67 may be secured to the upper end of the spring 60, but it is not fastened to the projection 64 or the bolt 66. Thus by turning the bolt 66, the bias of the spring 60 is changed which, in turn, effects an adjustment of the engagement pressure between the seal 50 and the plate 58 accordingly.

As shown in Fig. 2, a suitable fluid lubricant may be introduced through the grease inlet 68 (-via the grease fitting 63 which may be of any conventional type) to fill the outer end of the sinuous gas escape path. An overflow outlet 69 is provided in the wall member 32 for channeling olf any excess fluid. The fluid forms a column against which the gas may act, thereby aiding in preventing direct contact of the gas with the seal ring 50.

The segmental annular wall sections or members 56 and 58 may be connected together in end-to-end relationship, and are best shown in Figs. 4 and 5, wherein each joint may include a dowel 70 and a coacting aperture 71, plus the aligned apertures 72-73 and 74-75 for receiving bolts therethrough. Additionally, the opposite ends of each section of the joint may be notched as shown at 77 (Fig. 5) to provide an interfitting lapped joint between the mating ends.

I claim:

1. Sealing means for a rotatable hopper of a blast furnace to prevent the escape of gases from the furnace around the hopper comprising, an annular member surrounding and connected to the hopper for rotation therewith, an annular plate element carried by said member in generally radially extending, fluid-tight relation therewith, said plate element providing a substantially horizontally disposed surface on one face thereof, a stationary substantially rigid structure of open inner side configuration surrounding said plate element and receiving the free outer portion of said plate element therein, said rigid structure comprising upper and lower sections detachably connected together and providing said structure with an outer side portion spaced from the outer extremity of said free outer portion of said plate element and vertically spaced inwardly extending top and bottom portions disposed in vertically spaced overlapping relation with said free outer portion of said plate element, said rigid structure in combination with said plate element providing a clearance for rotation of said hopper with respect to said furnace, a flexible generally annular sealing strip of polymeric material mounted on said stationary structure and projecting inwardly from said outer side portion thereof into overlapping engaged relation with said horizontal surface of said plate element to seal the space between said outer extremity of said free outer portion of said plate element and said outer side portion of said rigid structure, and spaced, independently actuatable spring means disposed between said rigid structure and said sealing strip and yieldably urging said sealing strip into healing engagement with said surface of said plate member.

2. Sealing means in accordance with claim 1 wherein said sealing strip comprises rigid arcuate shaped segments cemented to one of the horizontal surfaces of the said sealing strip adjacent the inner periphery thereof, said spring means engaging said rigid segments to urge the opposite surface of said sealing strip into sealing relation with said surface of said plate member.

3. Sealing means in accordance with claim 1 wherein the lower portion of said first mentioned annular member extends below said plate element and forms with said lower section of said stationary structure a grease chamber beneath said sealing strip, said grease chamber being in direct communication with the path of movement of the gases from the furnace to said sealing means.

4. Sealing means according to claim 1 wherein each of said upper and lower sections of said stationary structure and said annular plate element comprises a plurality of arcuate segments forming the respective complete part, means detachably connecting together in end-to-end relation the respective segments of each part, and means on the terminal ends of said segments of at least said lower section and said plate element parts for aligning the respective segments in end-to-end relation prior to their being connected together into integral form, said last mentioned means comprising at least one dowel element on one end of each of the segments and a complementary aperture in the opposing end of the next adjacent segment.

5. Sealing means for a rotatable hopper of a blast furnace to prevent the escape of gases from the furnace about the hopper comprising, an annular member surrounding and connected to said hopper for rotation therewith, an annular flat plate element carried by said member in generally radially extending, fluid-tight relation therewith and providing an upwardly facing generally horizontal bearing surface thereon, a stationary substantially rigid structure of open inner side construction surrounding said plate element and receiving the free outer portion of said plate element therein, said rigid structure comprising upper and lower sections detachably connected together and providing said structure with an outer side portion spaced from the outer extremity of said free outer portion of said plate element and vertically spaced inwardly extending top and bottom portions disposed in vertically spaced overlapping relation with said free outer portion of said plate element, said rigid structure in combination with said plate element providing a clearance for rotation of said hopper with respect to said furnace, a flexible generally annular sealing strip of polymeric material mounted on said stationary structure and projecting generally horizontally inwardly from said side portion thereof into overlapping engaged relation with said horizontal surface of said plate member, to seal the space between said free outer portion of said plate element and said side portion of said stationary structure, a plurality of spaced, independent coil springs supported on the upper side of said sealing strip about the annular extent thereof and directly above said free outer portion of said plate element, each of said springs having a spring cap supported on the top thereof, and a manually actuatable threaded stud member disposed above each of said caps and being threadedly mounted in vertically adjustable relation on said top section of said rigid structure, the bottom end of each of said threaded stud members being engageable with the respective cap to adjust the compression of the associated spring thereby adjusting the engagement pressure between the underlying sealing strip and plate element.

References Cited in the file of this patent UNITED STATES PATENTS 2,718,971 Yuengling Sept. 27, 1955

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