THE COLLIERY GUARDIAN

AND

JOURNAL OF THE COAL AND IRON TRADES.

Vol. CVIII.

FRIDAY JULY 10, 1914.

No. 2793.

Mechanical Charging Cars for Coke Ovens.

By A. THAU, Coke Oven Manager, Llwynypia, Glam.

With the introduction of the modern retort coke oven
the charging arrangements as applied to the old beehive
ovens were adopted in precisely the same manner, and
thus represented a very costly means of charging, not
only as regards labour, but also owing to loss of time
and gas.

On the beehive ovens the charging was somewhat
easier than on the retort ovens, as there is only one
charging hole in the crown of the oven, from which the
coal is levelled equally all round, which, of course, is

Fig. 1.

under the bunker, brought to the oven to be charged,
and over the open charge hole the slide was removed,
and the coal transferred in the oven either by poking it
down with rods or by knocking against the sides of the
tubs. To prevent the coal from sticking to the sides of
the tubs different shaped tubs were employed—round,
oval, square with rounded corners, etc. They were
pushed to and from the ovens either by men, or pulled
by horses. In a few cases endless rope haulages were
employed to drive the tubs. Rope haulages are very

the coking coal was compressed into a box of the same
shape as the oven, with movable bottom, and, after the
coke was pushed out, the coal cake is carried on the
movable bottom, or peel, and transferred into the oven;
the oven door is then lowered, and the peel withdrawn.
While this arrangement was introduced originally with
the intention of coking coal which, under ordinary cir-
cumstances, would not make a good coke, it soon was
universally adopted as a means of mechanically charging
the ovens, and at one time was met with great enthu-
siasm. In practice, however, it was soon found that a
coal containing under 26 per cent, of volatile matter is
not suitable for compressing, inasmuch as the expan-
sion of the coal by the heat while coking is greater than
the shrinkage, owing to the loss of volatile matter, and it
is thus impossible, or very difficult, to push the coke out
of the ovens. In cases of very lean coal the expansion
of the compressed charge was even so great as to bend
the side walls of the ovens, while the coke rose into the
charging holes. In addition, the compressing of the
coal requires a proper condition of the coal, as regards
fineness and its contents of moisture, as, with too much
or too little moisture, the coal cake will not bind suffi-
ciently and break while charging, and fall between the
rails of the pushing and charging machine, from where
it is rather awkward to remove. In addition, the
upkeep of a compressing plant is rather expensive, so
that the savings as compared with hand charging are
not so very great.

These facts were soon recognised, and the compress-
ing plant has, as a mechanical charging arrangement,
been completely abandoned. It is, however, still in
extensive use on such plants where the quality of the
coal requires a compression in order to obtain a satis-
factory coke.

For quite a long time the old method, as described
before, of using coal tubs moved by hand, were used for
charging the ovens from the top, but in recent years this
rather costly arrangement is, on new plants, rapidly
being abandoned in favour of electrically-driven
charging cars.

The electric charging lorry is not a new invention, and
was even employed on beehive ovens. One of the first
firms making electrically-driven cars in this country was
Messrs. Coulson and Company Limited, of Spennymoor.
Their first electrically-driven charging lorry for beehive

Fig. 2.



much easier than to distribute the coal in only two
directions, as is the case in the retort ovens. Further,
the ovens are so cold that the coal does not ignite or give
off a lot of gas while charging, as is the case with the
retort ovens, and thus makes the work less strenuous
for the men working on top of beehive ovens. The top
of the beehive ovens is also much cooler compared with
retort ovens, so that horses can easily be used for bring-
ing the coal tubs to and from the ovens, but the use of
horses on the top of retort ovens, although done in some
cases, is a cruelty, and ruins their hoofs in a very short
time.

The old way of charging is so well known that it
hardly needs to be fully described. Funnel-shaped tubs
are used, the bottom of which reaches down between the
axles, and is closed here by a slide. The tubs are filled

hindering on the top of the ovens, however, and such
arrangements have only met with success on those
plants where the coal bunker is fairly distant from the
oven batteries, and the tubs are hauled to and from the
bunker up to the end of the battery, where they are dis-
connected and pushed to the particular oven by men.

With the introduction of the by-product coke oven
the collieries soon recognised that there was no better
way of dealing with their, at one time, very cheap quan-
tities of small coal than to convert them into coke, and
special efforts were made to try and coke coals which,
under ordinary circumstances, would not bind to a coke
large enough in size for metallurgical purposes, or
yielded a coke with too porous a structure. The
endeavours of the coke oven engineers to overcome these
difficulties resulted in coal compressing plants. In these

ovens is shown in fig. 1. It consists of a double hopper
carried by a frame, which rests on two axles with travel-
ling wheels. On one end of the hoppers a driver cabin
is arranged, which contains motor, driving gear, switch,
controller, and two levers to operate the slides under-
neath the hoppers. There is ample room for one man
in the cabin, and the end plate is provided with two
circular windows to enable the driver to see in front of
him whilst travelling. On top of the cabin an arm,
with trolley pulley on its end, is arranged so that it is
continually in contact with an overhead wire, and sup-
plies the current to the motor. The motor drives a gear
wheel, the shaft of which carries a sprocket wheel which,
by means of a Reynolds chain, works one of the axles
on which the car rests. The motor is reversible, and
its speed can be regulated by a controller. The driving