1022

THE COLLIERY GUARDIAN.

May 8, 1914.

bustion then rises through the hot regenerator /,
and absorbs the accumulated heat. The gases of
combustion then descend through the pipes k, and
pass through i and g into the regenerator /, where
they part with heat and then pass through e, d and
c to the chimney. When the coking chamber m is
filled with coal, all the doors, charging mouths,
etc., are made airtight. The gases generated in m
ascend through the pipe o and valve p into the
receiver q, whence it is removed to the by-product
recovery plant through the suction pipe r. For
the production of gas for lighting purposes, the

mliff

Fig. 18.—General View of Coke Oven Battery.

be

Fig. 20.—Cross-Sections
on the Lines AB, CD,
and E F (Fig 19).

Fig. 19.—Longitudinal Section Through Oven.

during the charging of the ovens are drawn off by
the chimney draught, through branches t of the
upcast pipes and through a flue s above the ovens.

The quenched coke is mostly tipped direct into
railway wagons, but about 25 per cent, is crushed
and sized on the premises. The cokery employs
36 men per shift; and this figure will be reduced
when the other batteries are ready.

The coking coal used contains 11-12 per cent, of
moisture; and the coke produced contains about
3.5 per cent., together with an average of 8 per
cent, of ash. One half of the gas recovered is

the gases. The arrangement of the supporting
pillars in the path of the entering air produces a
better distribution of the latter to the gas nozzles.

By-Products Recovery.

The plant for this purpose is divided into tar,
ammonia and benzol recovery plant. The ammonia
is recovered by the semi-direct process, the chief
difficulty of which is the removal of the mist of
suspended tar from the hot gases. In the present
case this is effected very completely by cooling the
gases and spraying them with water, so that only
the hydrocarbons which are gaseous at the tempera-
ture prevailing in the apparatus pass, with the
gases, through the saturator and condensers, for
the recovery of benzol. The products retained by
the condenser, which consist of tar and ammonia
liquor, are run into a separating tank, where they
separate out according to gravity, the tar being
pumped into a loading tank whilst the water is
returned to the sprayers. The purified gas is
forced by a turbo-blower, through a saturator
charged with sulphuric acid; and the precipitated
sulphate of ammonia is removed by steam or
pneumatic ejectors, drained in the hydro-extractor
and sent into store. The gas liquor condensed in
the condensers (about 15,500 gals, per diem from
60 ovens) is distilled along with milk of lime, the
ammonia vapours being passed through the
saturator, whilst the condensed water is run off to
settling tanks and freed from accompanying lime.
In this system there are only two sources of loss:
the still effluent and the final gas, the former con-
taining about 6.002 per cent, of ammonia, and the
latter about 2 grammes of ammonia in 100 cubic
metres.

The tar yield is 3.4 per cent, and that of sulphate
of ammonia 1.2 per cent, of the (dry) coal. The
120 ovens now running furnish 330-340 tons of sul-
phate of ammonia per month. The product is in
large crystals, containing 25 per cent, of ammonia,
and is perfectly white. A crusher is provided for
the preparation of crushed and dried sulphate,
containing 25j per cent, of ammonia. The plant is
shown in fig 21.

Benzol.—The sulphuric acid in the saturator has
no effect on the benzol hydrocarbons in the gas. In
the benzol plant the gas is cooled in an atmospheric
condenser, light tar oils and naphthalene being
condensed with the water, but separating from the
latter by gravity. It is intended to replace this
condenser by a naphthalene washer. The next
stage is to pass the gas through a series of four
benzol washers, 81 ft. in diameter and 74 ft. high,
containing a number of wooden gratings. The
washing oil meets the gases in its descent through
the washer, and collects in a pit, for removal.to
the benzol plant (fig. 22). This is equipped with
two Kubierschky column stills- and the requisite
accessories and purifying appliances. The crude
distillate is pale in colour, and of such constitu-
tion that 50-55 per cent, passes over when distilled
at 120 degs. Cent. The crude benzol, toluol, and
solvent naphtha 1 and 2 are stored in separate
tanks, and refined with commercial sulphuric acid
and redistilled. The still residues are transferred
to naphthalene pans, in which the naphthalene
crystallises out. The yield of refined benzols is
0.65 per cent., referred to dry coal, the monthly out-
put being 180 tons. About 85-90 per cent, of the
benzol is extracted from the gases.

Additional Plant.

The colliery is connected with the State Rail-
way at Repelen by a branch line five miles in length

w

Fig. 21.—Sulphate of Ammonia Plant.







T

L

JI

•	-'a

sI

-’swis i

Fig. 22.—Benzol Plant.

receiver of one battery is divided into two unequal
parts, the smaller being connected up to the ovens
during the period at which the coal gives off the
gas .with the greatest heating capacity.

.Since the charging truck takes up nearly the full
width of the ovens, the removal of the gases through
the upcast pipes had to be effected from the one end,
that nearest the pusher. It is found, however, that
the longer passage of the gases under the hot top
of the ovens does not lessen the yield of tar, benzol
and ammonia, as was feared. The gases produced

required for heating the ovens, the rest being
utilised for steam raising. The gas has the com-
position: CO2 2.1 per cent.; heavy hydrocarbons
2.0; O 0.4; CO 6.0; H 52.8; CH4 26.1 ; N 10.6 per
cent. The coal being well adapted for coking and
the heating arrangements of the ovens well
designed, a coke of excellent quality is obtained,
the yield being also large. The main advantage
of this type of coke oven is that the low situation
of the upper horizontal flue keeps the oven cool at
the top and prevents excessive decomposition of

with a four-track siding at that station. To
supply sand for the hydraulic gob stowing two
sandstone quarries have been acquired nearly a
mile away from the pit, and the sandstone is
carried by an aerial ropeway to No. 2 shaft, where
it is broken in a crusher. A ring-kiln brickworks
on the premises has a capacity of five to six million
bricks per annum, most of which will be consumed
for buildings connected with the colliery, it being
intended to provide housing accommodation to the
extent of about double the number of houses (1,400)