US2920017A - Lock for coke-oven filling holes - Google Patents

Description

Jan. 5, 1960 J. LlMBERG 2,920,017

LOCK FOR COKE-OVEN FILLING HOLES Filed June 27, 1957 2 Sheets-Sheet 1 Fly. 75

nan/r ed es Pat 0.

LOCK FOR COKE-OVEN FILLING HOLES Josef Limberg, Gahlen, Rhineland, Germany Application June '27, 1957, Serial No. 668,412

Claims priority, application Germany April 17, 1957 1 Claim. (Cl. 202-250) My present invention relates to locks for coke ovens and similar installations of the type having a heating chamber with a filling hole at the top.

Known locks of this character consist of two spacedapart, superposed covers whose vertical separation reduces the heat losses from the chamber. Each of these covers is usually formed with a beveled peripheral flange mating with the frusto-conical wall of the filling hole, the flange and the wall making area contact with each other over an annular surface having a width of about one to two centimeters. In order to insure uniform contact throughout this surface, it has been the practice to provide each cover with a low center of gravity by curving it downwardly at its center.

It has been found, however, that unavoidable deposits of tar and other combustion products along the fillinghole wall frequently prevent a proper seating of the cover so that the desired tight seal of the oven chamber is not achieved. Moreover, the proximity of the depending central portion of the lower cover to the smoldering coal/ coke pile within the oven quite often scorches the underside of this cover over a circular area; this area thus becomes weakened and is eventually penetrated by gases and fumes which then gather in the space between the two covers so as further to increase the leakiness of the lock.

My present invention has for its object the provision of an improved lock, of the general character set forth, by means of which a tight seal is afforded even after prolonged operation of the oven and which avoids the disadvantages outlined above.

A lock in accordance with this invention comprises a lid assembly including at least one cover whose seating surface is in the shape of a thin annular ridge formed on a peripheral flange of greater width, this ridge in effect constituting a cutting edge which will easily penetrate any layer of tar or other residue that may have formed on its seat, especially if a slight rotary motion is imparted to the cover during its positioning in the filling hole. This thin ridge will readily position itself at the proper level on the machine, frustoconical seating surface of the oven frame even after its initially sharp edge has become somewhat dulled by prolonged use. A tight seal is thus afforded without the necessity of curving the cover downwardly to provide a low center of gravity, hence the underside of the lid assembly facing the interior of the oven chamber can be made substantially flat so as to be subjected to a more uniform heating action which greatly retards its deterioration.

According to another feature of my invention, the peripheral flange bearing the ridge is beveled below the ridge at an angle greater than that of the frustoconical seating surface so as to form therewith an annular space of wedge-shaped cross-section within which tars may deposit without interfering with the seating of the cover, these tars effectively acting as an additional seal. A similar annular space may be formed above the ridge 2 and may, if desired, be filled with a liquid sealing agent, such as argillaceous water.

In accordance with a further feature of my invention, the lock comprises a single lid formed by combining the two vertically spaced covers into a unit, this lid having an internal cavity which may be filled with a suitable thermal 'insulant in order to reduce heat losses in essentially the same manner as does the two-cover structure.

Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description, reference being had to the accompanying drawing in which:

Figs. 1A and 1B show, in axial section and in top plan View, respectively, a lock according to the invention comprising separate upper and lower covers;

Figs. 2A and 2B show, in views analogous to those of Figs. 1A and 13, a modified lock according to the invention having a single lid; and

Fig. 3 is an enlarged fragmentary view of the left-hand portion'of the unit of Fig. 2A.

In Figs. :IA and 13 I have shown a frame 1, forming part ofa coke oven not further illustrated, which defines a frustoconical, downwardly converging filling hole 2. The walls 'of this hole are in part machined to form two annular, beveled zones 2a and 2b each between about 10 and 20 millimeters in width. The horizontal filling hole 2 is adapted to be closed by a lid assembly comprising a lower cover 3a and an upper cover 3b. Cover 3a, which is generally disk-shaped, has aperipheral flangefie forming a beveled seating surface complementary to zone 2a and making area contact therewith in the conventional manner, the width of this surface being approximately equal to that of zone 2a. Cover 3b, also disk-shaped, is formed with a thin, edge-like peripheral ridge 30 whose width is a fraction of that of zone 2b with which it is in all-around contact. Further details of the construction of the flange portion bearing the ridge 3c will be described in connection with Fig. 3 showing the relationship of the parts on a larger scale. The covers are readily removable from hole 2 by means of countersunk handles 6a and 6b, respectively.

The underside 3d of cover 3a is flattened so as to be exposed substantially uniformly to the heating effect of the carbonaceous pile (not shown) in the underlying chamber. While this construction results in a center of gravity for cover 3a which is somewhat higher than it would be if its underside were curved as illustrated in dot-dash lines, that fact is not objectionable since the novel construction of upper cover 312 provides an effective seal irrespective of the degree of closeness of the fit between flange 3e and its seating surface 2a. It is to be understood, however, that flange 3e might also be provided with a supporting surface of the knife-edge type, similar to ridge 3c of cover 3b, if fuller utilization of the principles of my present invention is desired.

In Figs. 2A, 2B and 3 I have shown a modified lock according to the invention in which a frame 1' is provided with a single machined seating surface 2a. A lower cover member 3a and an upper cover member 3b are integrally cast to form a single lid 3 whose internal cavity, separating the two cover members, is filled with a thermally insulating substance 4. Holes 5 in upper cover member 3b serve for the removal of the sand core from the cavity after molding as well as for the escape of accumulated gases and for the introduction of the insulating mass 4; they may subsequently be closed by threaded plugs 5a as illustrated in dot-dash lines in Fig. 3. For easier manipulation of lid 3 I have shown the latter provided, in lieu of the handles 6a and 6b of Figs. 1A and 1B, with a wrought-iron plate 7 secured by screws 11 to a cylindrical neck 12 rising integrally from cover member 312'; this plate 7 is adapted to serve as an armature for an electromagnet (not shown) used in lifting the lid 3 into and out of the filling hole. A flat iron bar 8 with downturned ends is lodged in recesses of the neck and held in place by the plate 7 to enable lifting of the lid 3 by hand or with the aid of a mechanical crane in the event of failure or unavailability of the electromagnetic hoist.

Reference will now be made to Fig. 3 for a detailed description of my novel seating arrangement. The machined surface 2b may be assumed to have a width of about to millimeters. Lid 3 is peripherally encircled, at the junction of its upper and lower members 3a and 3b, by a narrow ridge 3c extending only over a fraction of the width of zone 2b, this ridge being sharp enough to cut into the layer of coal tar and other residue usually deposited on the Walls of filing holes of coke ovens and the like. The restricted zone of contact between ridge 3c' and seating surface 2b has been indicated at A. To facilitate penetration of this layer and to insure a perfect fit, the lid 3 may be rotated by means of the handle 8 after having been lowered into its seat. The flange carrying the ridge 30' has a beveled surface 3e underneath the ridge which together with seating surface 2b' defines an annular channel 9 of wedge-shaped cross-section; tar deposits quickly form in this channel and act as a packing which supplements the sealing action of the lid. Another beveled flange surface above ridge 3c forms a similar but inverted channel 10 which, if desired, may be filled with a sealing fluid poured into it from above. Thus, the two beveled surfaces above and below ridge 30' may be described as chamfers adjoining this ridge at obtuse angles.

It will be understood that the ridge 3c in Fig. 1A is substantially identical with ridge 3c and, as shown, is bounded below and above by annular spaces similar to channels 9 and 10.

My invention is, of course, not limited to the specific embodiments described and illustrated but may be realized in various modifications and adaptations without departing from the spirit and scope of the appended claims. Thus it will be understood, for example, that the two machined zones 2a, 2b of Fig. 1A might be merged into a single seating surface.

I claim:

A filling-hole lock for coke ovens and the like, comprising a generally disk-shaped cover member provided with a peripheral flange, said flange having an upper and a lower chamfer forming a ridge at their junction, said chamfers being in the form of frustoconical surfaces diverging toward said ridge and having their generatrices enclose an obtuse angle with each other, said ridge being substantially narrower than said chamfers and forming a cutting edge adapted to penetrate a layer of combustion residue on a seating surface for said cover member.

References Cited in the file of this patent UNITED STATES PATENTS 137,704 Mcllhenney Apr. 8, 1873 142,253 McIlhenney Aug. 26, 1873 FOREIGN PATENTS 319,872 Great Britain Oct. 3, 1929 165,144 Germany Jan. 31, 1904 681,741 Germany Sept. 30, 1939 750,980 Germany June 1, 1944

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