August 20, 1915.

THE COLLIERY GUARDIAN.

383

SELF-TIGHTENING DOORS FOR COKE
OVENS/

Within the last few years experiments have been
carried on in German cokeries with self-tightening coke
oven doors, which do not require packing or luting with
loam, sand, ground firebrick, coke breeze, etc. The
chief types of these doors are the Bareuter, Limberg and
Koppers. The first-named is made in several patterns,
the most recent being the one illustrated in figs. 1 to 3.
Here the door is built up of separate castings a, which
are riveted on to a flexible plate b, so as to leave narrow
gaps c, which are packed with asbestos. The plates a

Fig. 2.—Vertical
section.

Fig. 1.—Front view,

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Fig. 3.—Horizontal section.

Figs. 1-3.—Bareuter Coke Oven Door.

Fig. 4.—Front view.

Fig. 5.—Vertical
section.

Fig. 8 — Vertical section.

Fig. 7.—Front view.

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Figs. 4-6.—Limberg Coke Oven Door.

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Fig. 9.—Horizontal section.

Figs. 7-9.—Koppers Coke Oven Door.

are also fastened together by means of bolts d, and each
of them is provided with a groove e to hold the flange /,
by means of which a tight joint is formed at the edges
of the door when the latter is pressed home by the screws
g, working in the crossbars h, one of which is provided
for each section of the door. The flexible plate enables
the door to adapt itself to irregularities in the face of the
coking chamber; whilst the gaps allow the separate

* A. Naderhoff, Gliickauf.

castings to expand, and prevent the distortion which
would occur if all the castings were in one piece. Doors
of this kind have been in constant use for over 12 months
without showing any signs of warping.

In the Limberg door (figs. 4 to 6), the door frame a
is an iron casting with bevel cheeks, the flanges resting
against the inside of the oven. The door b is of cast
iron, or else consists of a cast body and a plate facing c,
and wrought iron bands d are cast in with the door and
frame, to prevent tearing or breaking. An asbestos
ring e, with iron core, makes the joint tight all round the
door, by fitting between the projecting ridges g and Zi, on
the door and frame respectively. This arrangement is
better than simply jamming the ring between the plane
faces of the frame and a ridge on the door, as was the

case in the older patterns, since it prevents any unequal
slipping and lessens wear. The door is pressed home
by screws, i, f, guided in bars, k, kr, fitting behind
hooks I, bolted through the door frame. Two eyes m
are provided in front of the door for the handles used to
place the latter in position; and a horizontal rod in a
vertical slot n, near the top, enables the door to be lifted.
A number of these doors have been in use for two years,
and at four Westphalian cokeries whole batteries of
ovens are now provided with them, each door having a

number plate o, which ensures each one being employed
only for the oven to which it belongs.

The Koppers door (figs. 7 to 9) fits into a cast iron
frame a, the outer face b of which is machined. The
door itself is made in two parts; an outer sheet iron
box c, filled with kieselguhr, and an inner, cast iron
fire plate d, faced, on the oven side, with fireclay. The
sheet iron box is secured to the outer, wrought iron door
plate c, whilst the fireplate is hinged on the box, so that
it protects the door plate and at the same time does not
warp the latter when expanding and contracting. To
the plate e is secured an angle-iron frame /, the face of
which, on the oven side, is machined so as to fit snugly
against the machined face b. The door is held in
position by crossbars g, which slip into catches h,
attached to the door frame. On the pusher side of the
oven the doors have two such crossbars, whilst on the
discharge side, being higher, they have three. Set
screws i, in the crossbars, force the machined faces of
the door and the door frame into close contact, and make
a tight joint.

Both the Limberg and Koppers doors being recessed
into the face of the oven, a compound movement is
required in taking them out and replacing them, the first
part of this movement (in the former case) being largely
horizontal. These movements are effected, for example,
by the Koppers swing crane (fig. 8), mounted on the coke
pusher. When the crane is opposite the oven, a recess
in the bracket, k, engages under a lug Z, on the oven
door. By turning the hand wheel m, the door is first
raised out of contact with the sill, then drawn forward

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Fig. 10.—Wilhelm Electric
Winch for Self-tightening
Coke Oven Doors.

by running the carriage n back along the girder o, and
turned out of the way by swinging the crane to one- side.
The buffer p prevents the door from tilting.

At one cokery the doors on the discharge side of the
ovens are handled by a Wilhelm electric winch (fig. 10)
mounted on the top of the ovens. The winch chain
engages the crown of a bell-crank lever a, the one limb
of which rests in a channel b in the oven wall, whilst the
other limb grips the door. On starting the winch the
lever rotates about the fulcrum of the upper limb until
the crown is exactly over the point of engagement of the
hook with the door, by which means the latter is swung
out of contact with the frame, whereupon the further
pull of the chain draws the door straight up, the upper
limb of the lever slipping out of the channel. To replace
the door the operations are reversed.

All these types of door are perfectly tight, there being
no sign of combustion of the coke by admitted air. In
the Koppers door no packing material is required, and in
the other two the need for renewal is infrequent, that
of the Limberg door lasting about six weeks, whilst
Bareuter doors have been used for a year without needing
fresh packing rings. Even assuming the life of the rings
to average only three months, the cost, per battery of
60 ovens, would not exceed T240 per annum, or very
little more than the loam luting of ordinary coke oven
doors. On the other hand, with such a battery, the
saving in labour is about d£600 per annum; and as the