Improvements in the Production of Coke for Foundry and other Purposes.
Year: 1890

page_text: Date of Application, 29th Nov., 1890
Complete Specification Left, 26th Sept., 1891-Accepted, 21st Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Production of Coke for Foundry and other
Purposes.
I, FREDERICK JOSIAH JONES of 61, Goldington Road, Bedford, in the
County of Bedford, Engineer, do hereby declare the nature of this invention to
be as follows :-
My invention relates to improvements in the process of making coke which
formed the subject of a previous application for Letters Patent dated July 26th
1889 No. 11920.
In the said process the coking of the coal is effected by the passage transversely
through a thin vertical stratum of coal of the hot gases of combustion of fuel in
a separate gas producer furnace.
When the operation is so conducted it is found that the coke produced is liable
under certain circumstances to be contaminated by the impurities particularly the
sulphur-contained in the fuel consumed in the gas-producer furnace; and the
object of my present improvement is to avoid this objection and to utilize the gases
given off in the coking operation (or in the preliminary stage thereof) in a
purified condition for the purpose either of completely coking another charge or
for completing the coking of the same charge and at same time sweeping out the
impurities which may have become absorbed or deposited therein during the initial
stages of the operation.
It will be apparent that, if the gases given off in the operation of coking a
charge are sufficient to repeat the operation on another charge, the gases from the
producer would only be used once, namely at starting the operation for coking the
charge in the first oven or first pair of ovens of a series, the coking of the charges
in the succeeding ovens of the series being effected by the gases (purified and
reheated) coming off from the other ovens, the timing of the heats and of the
intermediate operations being so arranged as to make the cycle of operations cou-
tinuous through the whole series of ovens.
By so using the purified gases a purer kind of coke will be produced than when
crude gases are used as in my previous process, and the process differs from all
others in that there is practically no loss of heat and the gases used are practically
everlasting, simply alternating in composition from a rich gas, consisting largely
of carbonic oxide, to carbonic dioxide and back again from carbonic dioxide to the
rich gas, etc., as in each complete cycle the CO, made in the combustion chamber
in passing through the body of the hot coking mass becomes changed and highly
charged with tarry vapors, ammonia, and other gaseous constituents.
The improvement comprises also a method of purifying the gases and recovering
the sulphur and other valuable bye-products therefrom.
The ovens, as before, are situated between and communicate by orifices in the
division walls with a combustion chamber on the one side and a gas collecting
chamber on the other side, as described in my said former Specification. The
gases pass off from the gas-collecting chambers through a flue common to all
and provided with suitable valves to a horizontal condenser which may be of the
ordinary construction as used in gas-works. From this the uncondensed gases are
extracted by an exhauster and forced through a scrubber also of the ordinary
kind used in gas-works, the condensed products from both the condenser and
scrubber flowing into a tar-settling tank whence the ammonia separated therein
overflows into a tank. From the scrubber the washed gases pass to purifiers and

page_text: thence to a reheater where they are raised to the requisite temperature before
being passed through the charge to be coked as above described.
Dated this 29th day of November 1890.
F. J. JONES.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in the Production of Coke for Foundry and other
Purposes.
I FREDERICK JOSIAH JONES, of 61 Goldington Road, Bedford in the County
of Bedford, Engineer do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
My invention relates to improvements in the process of making coke for which
I obtained former Letters Patent dated July 26th 1889 No. 11920. In the
process therein described the coking of the coal is effected by the passage trans-
versely through a thin vertical stratum of coal, of the hot gases resulting from
the combustion of producer gas generated in a separate gas producer furnace.
In this process as heretofore conducted the coke produced is liable to be con-
taminated by the volatilizable impurities-particularly the sulphur-contained in
the fuel consumed in the gas producer furnace whilst the gases resulting from the
coking operation are virtually wasted.
The object of my present improvement is both to avoid this contamination with
sulphur and to utilise to greater advantage the gases resulting from the coking
operation. With this object the gases given off in the coking operation are first
purified and then reheated, and in that condition are used for the purpose of con-
tinuing the coking operation, either on the same or a different charge, and at same
time sweeping out the impurities contained in the charge. By purifying the gases
and using them as above described, a much purer kind of coke will be produced
than when crude gases from the producer furnace are used and the ammonia,
sulphur and other valuable bye-products may be recovered.
As the gases given off in the operation of coking a charge are more than
sufficient to enable the operation to be repeated on another. charge, the producer
gases need only to be used for coking purposes at starting, that is to say for the
purpose of coking the charge in the first oven (or first pair of ovens) of a series,
the coking of the charges in the succeeding ovens of the series being effected by
the gases (purified and reheated) coming from the ovens already at work, and so
on, the timing of the heats and of the intermediate operations being so arranged
as to make the cycle of operations continuous through the whole series of ovens.
The principal use of the producer in all the coking operations after the first, is
therefore to reheat the gases after purification and prior to their re-use for
repeating the coking operation, the gases used being theoretically everlasting and
simply alternating in composition from carbon dioxide to a rich gas consisting
largely of carbonic oxide and back again to a gas consisting of carbon dioxide,
and so on, as in each complete cycle the carbon dioxide made in the combustion
chamber becomes changed in passing through the hot coking mass, the gases
becoming highly charged with tarry vapors, ammonia, and other gaseous con-
stituents. The reheating of the gases might therefore be effected without admix-
ture with the producer gases which would in that case only be passed through the
first charge of coal but in practice it is preferred that the gases after purification
should be reheated by being mixed with the gases from the gas-producer and to
avoid contamination of the gases with impurities contained in the fuel, the pro-
ducer is fed with the "breeze" or small coke resulting from a previous charge,
which having been coked by this process will be pure.

page_text: The invention will be more fully described with reference to the accompanying
drawings, forming part of this Specification, which illustrates in Figure 1 a general
plan of the ovens, the apparatus for purifying the coke oven gases, extracting the
bye-products therefrom and returning the purified gases to the ovens.
Figure 2 is a side elevation, partly in section on line 1-1 Figure 3, of a set of
six pairs of ovens and the producer-furnace in connection therewith.
Figure 3 is a cross-sectional elevation through a pair of ovens, one being open
and the charge being represented as in the act of being drawn.
Figure 4 is a section through one of the gas-collecting chambers.
Figure 5 is a vertical section, and Figure 6 a horizontal section, of one of
the purifiers.
The same letters of reference indicate the same parts in all the figures.
A A', A A', are pairs of ovens, each pair being situated between a combustion
chamber B on the one side and a gas-collecting chamber C on the other side,
these chambers being common to the two ovens of a pair which communicate with
said chambers respectively by orifices be in the division walls. Each combustion
chamber B is preferably placed between two pairs of ovens A A¹ and is common
to both pairs.
Each oven A is a long narrow upright chamber of approximately equal length
and height but of a breadth of only about one-tenth the height, the roof and
floor being inclined at a pitch of, say, about 35°. The most important dimension
is the breadth which is governed by the permeability of the mass by the gases of
combustion, this being in turn dependent on the kind of coal and size of the
pieces. I find that fourteen inches is a good working dimension for the average
breadth of the oven for coking what is known as "smudge" or "duff" or
eighteen inches for coking rough slack. The sides of the oven should not, how-
ever, be quite parallel but should be slightly wider apart at the front of the oven
to facilitate drawing the charge. The orifices be in said walls are of such size
that they will not be filled and choked by the coal and may be made either by
using perforated fireclay lumps or by leaving open (to the extent of about a
quarter of an inch) all the vertical joints of the brickwork of the side walls from
the floor a up to the shoulder a' above which the brickwork is solid, these per-
forated walls being prevented from bulging by headers or cross-ties of firebrick
crossing the chambers B C and binding their opposite walls together, as shewn in
Figure 2. The opposite side walls of the ovens being thus perforated over
practically the whole area of the charge, the products of combustion in passing
from chamber B to the gas-collecting chamber C will pass across the ovens and be
uniformly distributed through and be caused to traverse in the direction of its least
thickness, the whole mass of coal contained therein.
The ovens of each pair A A¹ are set back to back or with their higher and
narrower ends together and each pair has a charging mouth A² closed by a cover
and common to the two ovens A A', the cross-division wall between the inner ends
of the ovens being only high enough to separate the masses of coke without inter-
fering with the free charging of both ovens from the one mouth A. In order to
enable the coke to be discharged "en bloc" and with little waste or labor, each
oven floor a is inclined downwards towards the front end where is situated the dis-
charging aperture extending the full width and height of the oven and closed by
sand luted doors D D', the downward inclination of the floor being continued
outside the oven to enable the mass of coke to be slid out with little or no
breakage. The perforated side walls of the ovens (especially when a shrinking
coal is intended to be used) have each a ledge or shoulder a' (before referred to)
about two inches in width inclined at a slightly greater pitch than the floor a and
situated at such a height that a sufficiency of the charge (which fills the oven nearly
to the roof) will rest on the shoulders a¹ and seal the passage left by the con-
traction in bulk of the coal in coking, in order to prevent the gases of combustion
passing round instead of through the charge towards the end of the coking

page_text: operation. In order to ensure the sufficient heating of the lower part of the charge,
the space E beneath the floor a (which is of firebrick) may communicate with the
lower part of the combustion chamber B by orifices e..
F is a gas-producer furnace communicating with the several combustion chambers
by a flue G provided with valves g of firebrick for controlling the passage of the
furnace gases to the combustion chambers. The furnace has air heating flues H
through which the air supplied to the combustion chambers passes.
At starting the cycle of operations, the combustion chambers B receive the
gases resulting from imperfect combustion in the gas-producer furnace F which
should be charged for this time only, with wood or charcoal to ensure the pro-
duction of a pure coke in the ovens from the very commencement of the operation.
The combustion of these gases is completed in the chambers B by the admission
of just sufficient hot air (through the air heating flues H and apertures h) to the
chambers B to produce as nearly perfect combustion as possible and the resulting
gases traverse the charge of coal in the ovens and are collected in chambers C.
In practice the supply of air should be so limited that there will be a slight
deficiency of oxygen so that the combustion of the producer gases in chambers B
will be nearly, but not quite, perfect which is denoted by their presenting a slightly
smoky appearance.
In the subsequent repetitions of the coking operation, the gases supplied to the
combustion chambers B are mainly those derived from the coking of other charges
(after purification and reheating as hereafter described) the producer gases being
only used alone in first starting the operation.
The gases after traversing the ovens are received in the gas-collecting chambers C,
whence they pass off through a single or double set of ascension pipes i and a hydraulic
main or mains II (which may be common to all the chambers C) to a condenser K
which may be of the ordinary construction as used in gas works. When coking
coal poor in bitumen the hydraulic mains might be dispensed with and the
chambers C connect directly with the condenser by flues 1' at bottom, as shewn in
dotted lines. From the condenser the uncondensed gases are extracted by an
exhauster (situated at L for example) and forced through a scrubber M also of
the ordinary kind used in gas works, the condensed products from both the
condenser and scrubber flowing into a tar settling tank N whence the ammonia
separated therein overflows into a tank O. From the scrubber M the washed
gases pass to one or more purifiers P P charged with lime or preferably with
oxide of iron, as in gas making. From the purifier the gases, now freed from
sulphur, return to the furnace F where they are raised to the requisite temperature
before being returned to the combustion chambers B for the purpose of being
passed through the charges contained in the ovens. For the purpose of reheating
the gases, the ordinary gas-producer furnace is provided with an inlet flue f
leading up through the furnace bridge through which the gases coming from the
purifier P or P₁ pass and are mixed above the bridge with the gases resulting
from imperfect combustion in said producer of pure fuel such as small pure coke
or "breeze" resulting from a previous coking operation by this process.
mixed gases are then conveyed to the several combustion chambers B and there
burnt in admixture with hot air admitted through flues H in sufficient quantity to
ensure almost, but not quite, perfect combustion the resulting gases passing
thence through the charges in the ovens.
The
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is―
1st. The herein described improved process of making coke for foundry and
other purposes, which consists in effecting the coking operation in ovens, con-
structed substantially as herein described, by the passage, transversely through a
thin vertical stratum of coal, of the hot gases resulting from the combustion of

page_text: the mixed gases produced at an earlier stage or by another coking operation after
said gases have been purified and reheated, substantially as and for the purpose
specified.
2nd. In the making of coke by the process and in ovens such as herein described,
the improvement which consists in eliminating from the mixed gases resulting from
the coking operation, the condensable constituents purifying and desulphurizing
the gases, then mixing them with fresh gas-producer gases (generated from pure fuel)
effecting their combustion with air, and finally passing the gases resulting from
such combustion through the same or other charges, as specified.
Dated September 25th 100
By A. M. & Wm. Clark,
F. J. JONES.
53, Chancery Lane, London, Chartered Patent Agents.