IMPROVEMENTS IN APPARATUS USED IN THE DISTILLATION OF COAL FOR THE PRODUCTION OF COKE, TAR, AND AMMONIACAL LIQUOR, AND THE UTILIZATION OF THE RESULTING GASES
Year: 1877

page_text: LETTERS PATENT to James Forbes and John Abbott, both of Old Ford, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN APPARATUS
USED IN THE DISTILLATION OF COAL FOR THE PRODUCTION OF COKE, TAR, AND
AMMONIACAL LIQUOR, AND THE UTILIZATION OF THE RESULTING GASES."
Sealed the 14th May 1878, and dated the 19th November 1877.
PROVISIONAL SPECIFICATION left by the said James Forbes and John
Abbott at the Office of the Commissioners of Patents on the 19th November
1877.
JAMES FORBES and JOHN ABBOTT, both of Old Ford, in the County of Middlesex.
"IMPROVEMENTS IN APPARATUS USED IN THE DISTILLATION OF COAL FOR THE
PRODUCTION OF COKE, TAR, AND AMMONIACAL LIQUOR, AND THE UTILIZATION OF
THE RESULTING GASES."
The objects of this Invention are to extract from the coal the maximum quantity
of tar and ammoniacal liquor, and to produce more economically a better quality of
coke than when coal is distilled in the ordinary way, the resulting gas arising
during this process being utilized for heating the retorts or ovens, which form the
subject of the present Invention.
The retorts or ovens, which are made of fire-brick, are of a semicircular or D shaped
form, about three feet in breadth, about twelve or fifteen inches high, and about
ten feet long. (The dimensions are only approximate, as they may be varied
to suit particular circumstances.) They may be set singly in brickwork, or a
number of them may be set in a bench or row. Beneath each retort are fixed
horizontally, parallel to the bottom of the retort, and about six inches therefrom,
slabs of fire-clay. Between these slabs and the bottom of the retort are fixed two,
three, or more partitions, made also of fire-brick. The partitions extend to nearly
the whole length of the retort, and divide the space beneath it into so many longi-
tudinal chambers or continuous flues, each partition having an opening at one end,
so as to admit of communication with the adjoining chambers. Beneath the slabs

page_text: ones.
just spoken of, another set of slabs are placed, also about six inches below the upper
The space between these slabs is divided in exactly the same manner as
before described, with the exception that in this case the chambers or continuous
flues are transverse, or at right angles to those immediately above them.
The retorts or ovens are furnished with mouth-pieces and lids at one or both ends
similar to those employed for the production of gas, and there are attached either to
one or both mouth-pieces of each retort an ascension pipe leading to an hydraulic
main. In connection with the main there is an exhauster for drawing off the gas from
the retorts, and forcing it through a condenser to extract the tar and ammoniacal
liquor, and through a washer or scrubber to arrest the remaining ammonia. The
gas is then passed on to a gas holder without further purification.
The mode of using the apparatus is as follows:-The retorts or ovens being
charged with coals, gas is allowed to flow from the gas holder through suitable pipes
to one end of the lowest series of chambers before described. When it reaches the
other extremity of these chambers or flues, and is about entering the upper series,
it is caused to combine with atmospheric air admitted through suitable orifices, and
is lighted. The heat generated by the burning gas is soon sufficient to disengage
from the coal in the retorts its gas, which rising to the hydraulic main is pumped
away through the condenser and scrubber, and from thence into the gas holder to
be conveyed beneath the retorts for distilling fresh coals. Thus a constant supply
gas is kept up, any excess being used for heating the vessels employed in manu-
facturing the tar and liquour into marketable commodities.
of
When a fresh charge of coals is put in the retort, it is desirable that the tem-
perature to which the coal is subjected should be kept low until the whole of the
tar is extracted, when the heat may be raised with advantage to the resulting
coke.
In practice it may be found desirable under some circumstances to have but one
series of chambers beneath the retorts instead of two, the air being admitted at
suitable openings placed at intervals.
Arrangement is also made for the admission of air into the retorts when
necessary.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Forbes and John Abbott in the Great Seal Patent Office
on the 16th May 1878.
JAMES FORBES and JOHN ABBOTT, both of Old Ford, in the County of Middlesex.
"IMPROVEMENTS IN APPARATUS USED IN THE DISTILLATION OF COAL FOR THE
PRODUCTION OF COKE, TAR, AND AMMONIACAL LIQUOR, AND THE UTILIZATION OF
THE RESULTING GASES."
The objects of this Invention are to extract from the coal the maximum quantity:
of tar and ammonical liquor, and to produce more economically a better quality of
coke than when coal is distilled in the ordinary way, the resulting gas arising
during this process being utilized for heating the retorts or ovens, which form the
subject of the present Invention.
The retorts or ovens, which are made of fire-brick, are of a semicircular or
D shaped form, about three feet in breadth, about twelve or fifteen inches high, and.
about ten feet long. (The dimensions are only approximate, as they may be varied.
to suit particular circumstances.) They may be set single in brickwork, or a number
of them may be set in a bench or row. Beneath each retort are fixed horizontally,
parallel to the bottom of the retort, and about six inches therefrom, slabs of fire-
clay. Between these slabs and the bottom of the retort are fixed two, three, or
more partitions, made also of fire-brick. The partitions extend to nearly the whole
length of the retort, and divide the space beneath it into so many longitudinal
chambers or continuous flues, each partition having an opening at one end, so as to'
admit of communication with the adjoining chambers. Beneath the slabs just
spoken of another set of slabs are placed, also about six inches below the upper ones.
The space between these slabs is divided in exactly the same manner as before
described, with the exception that in this case the chambers or continuous flues are.
transverse, or at right angles to those immediately above them.
The retorts or ovens are furnished with mouth-pieces and lids at one or both
ends, similar to those employed for the production of gas, and there are attached
either to one or both mouth-pieces of each retort an ascension pipe leading to an
hydraulic main. In connection with the main there is an exhauster for drawing
off the gas from the retorts, and forcing it through a condenser to extract the tar
and ammonical liquor, and through a washer or scrubber to arrest the remaining
ammonia. The gas is then passed on to a gas holder without further purification.
In order that the foregoing may be more easily understood, Drawings are.
attached hereto, of which the following is a description:-
Fig. 1 is a front elevation of a single bench containing one retort only.
Fig. 2 is a front sectional elevation through Y, Z, Fig. 4.
Fig. 3 is a section through A, B, Fig. 2; and Fig. 4 is a section through C, D,
Fig. 2.
In Fig 1 E is the retort bench; F, the lid of the retort; and G, the ascension
pipe leading from the mouth-piece to the hydraulic main; H is a pipe furnished
with a valve for the admission of gas to heat the retort; and I is a pipe, also
provided with a valve for the introduction of atmospheric air, which is mixed
with the gas at a proper point; J, J, J, are sight plugs.
In Fig. 2 K is the retort supported by the brick partitions L, L, which in their
turn are supported by the slabs M, M. These slabs rest upon brick partitions N, N,
which are upheld by the slabs O, O, and the ordinary brickwork beneath;
P is an
opening through which the mixed gas and air may be lighted, and has a plug for
closing it.
In the sectional plan, Fig. 3, N, N, are the brick partitions, as in Fig. 2; and
in the sectional plan, Fig. 4, L, L, are the partitions similarly marked in Fig. 2.
Although, for the sake of illustration, only one bench and one retort are shown,
they may be multiplied and set in continuous benches, care being taken to increase
the size of the flues in proportion to the quantity of gas necessary to heat the retorts,

page_text: In practice too the valves H and I would be removed farther away from the retort
stack than shown, in order to prevent their being destroyed by the heat.
In each of the Figures similar letters refer to the same parts.
The mode of using the apparatus is as follows:-The retort or oven K being
charged with coals, gas is allowed to flow from a gas holder through the pipe H to
one end of the lowest series of chambers or flues Q, Q, before described. When it
reaches near the other extremity of these chambers or flues, and is about entering
the upper series, it is caused to combine with atmospheric air, which is admitted
through the pipe I, and upon its entry into the upper series the combined gas and
air, represented by double arrows, is lighted at the point R through the opening P.
The burning gas traverses the flues or chambers S, S, heats the retort, and is
subsequently led off through an outlet T to the chimney shaft.
Instead of the gas passing away to the shaft at once, it may be led over the top
of the retort by a series of flues, but no claim is made to this arrangement. The
heat generated by the burning gas is soon sufficient to disengage from the coal in
the retorts its gas, which, rising to the hydraulic main, is pumped away through
the condenser and scrubber, and from thence into the gas holder to be conveyed
beneath the retorts for distilling fresh coals. Thus a constant supply of gas is kept
up, any excess being used for heating the vessels employed in manufacturing the
tar and liquor into marketable commodities.
When a fresh charge of coals is put in the retort, it is desirable that the tem-
perature to which the coal is subjected should be kept low until the whole of the
tar is extracted, when the heat may be raised with advantage to the resulting
coke.
In practice it may be found desirable under some circumstances to have but one
series of chambers beneath the retorts instead of two, the air being admitted at
suitable openings placed at intervals.
If it is thought desirable that after the gas is worked off, the coke should be
hardened by the introduction of atmospheric air, the lids may be slacked, and remain
so until a sufficiently dense coke is produced.
If also it should be found necessary, gas manufactured by ordinary apparatus
may be used in addition to heat the retorts already described.
Having now described and particularly set forth the nature of this Invention,
and the manner in which the same is or may be used or carried into effect, we would
observe in conclusion that we do not confine or restrict ourselves to the precise details
or arrangements which we have described or referred to, as variations may be made
therefrom without deviating from the principles or main features of this Invention,
but what we consider to be novel and original, and therefore claim as the Invention
secured to us by the herein-before in part recited Letters Patent is, the construction
of apparatus for the distillation of coal, whereby the gas arising from the said
distillation may be utilized for heating the retorts, as herein described, and shown
on the Drawings.
In witness whereof, we, the said James Forbes and John Abbott, have here-
unto set our hands and seals, this Ninth day of May, in the year of our Lord
One thousand eight hundred and seventy-eight.