Improvements in the Production of Coke for Foundry and other Purposes
Year: 1889

page_text: Date of Application, 26th July, 1889
Complete Specification Left, 28th Apr., 1890-Accepted 11th Oct. 1890
PROVISIONAL SPECIFICATION.
Improvements in the Production of Coke for Foundry and other
Purposes
I, FREDERICK JOSIAH JONES, of Godmersham House, Fish Pool Street, St. Albans
in the County of Herts, Engineer do hereby declare the nature of this invention to be
as follows:-
My invention relates to an improved method of manufacturing foundry coke of a
merchantable quality from coal not heretofore available for the purpose, or coke of a
superior quality from the same class of coal as is at present used.
According to this improved process the coking of the coal is effected by the
passage through the charge of the gases produced by combustion in a furnace, the
operation being so conducted that the volatilizable impurities are carried off and
consumed as they are generated instead of being retained in the coke oven.
The operation is performed in a vertical coking chamber situated between the
furnace on the one hand and a second combustion chamber on the other and com-
municating therewith by orifices in the opposite walls, a proper state of combustion
being maintained in the furnace by the aid of a suitable blast and the gaseous
products therefrom being caused to traverse the mass of coal in the coking chamber
the resulting mixture of gases passing thence to the second combustion chamber and
being there consumed.
The coking chamber has a double inclined floor, to facilitate the withdrawal of the
coke at opposite sides, means being provided for charging at a point above the highest
part of the flor and of separating the coke into two distinct masses.
The coking chamber being situated between the furnace and the second combustion
chamber is heated on both sides and may also be heated from below by the passage of
a portion of the products of combustion from the second combustion chamber beneath
the floor to the flue by which the products are finally carried off.
Dated this 26th day of July 1889
COMPLETE SPECIFICATION.
Improvements in the Production of Coke for Foundry and other
Purposes.
I, FREDERICK JOSIAH JONES of Godmersham House, Fish Pool Street, St. Albans,
in the County of Herts, Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates to an improyed process whereby foundry coke of a merchant-
able quality may be manufactured from coal so poor in bitumen as not to have been
heretofore available for the purpose; or whereby coke of superior quality may be
produced from the same class of coal as at present used.
In the ordinary method of making foundry coke it is usual to effect the expulsion
of the volatile constituents from the coal by their own combustion in the oven itself,
or in flues running beneath and around the ovens, the primary object being to obtain
a coke, of great density and hardness, free from sulphur. The process of coking
converts the coal into a porous mass during the melting of the coal by the collection
of the gases in the form of minute bubbles previous to their escape from the coal, and
it will, therefore, be obvious that the higher the superincumbent column of coal
[Price SAT

page_text: the greater will be the density of the resulting coke, but, in the ordinary form of
beehive oven, the greater also will be the obstruction to the liberation of gases and
the greater the liability of overburning the charge. Hence, in this form of oven,
the depth of the charge is limited, both for the above reasons and also because of the
difficulty of getting rid of the gaseous constituents of the coal without, at the saine
time, losing a comparatively large proportion of the solid carbon also.
In coke ovens of the gas-retort type, where no combustion takes place within the
oven, (the gases being burnt in flues surrounding the ovens) the waste of carbon is
reduced and the time required for the coking operation is shortened, but the purity of
the coke is impaired owing to the retention of sulphur consequent on the difficulty
with which the gases escape from the charge. The coke also loses in hardness
through absence of contact with flame within the oven, which it is well known
produces a sort of case-hardening effect on the lumps which is entirely absent from
the coke produced in the gas retort type of oven, notwithstanding that in some forins
of the latter the height of the column is sufficient to give the coke considerable
density. Consequently, experience has shewn that the quality of the coke obtained
in the ordinary oven without flues is so far superior to that produced in the gas
retort type of oyen as to compensate for the loss of carbon and the greater time
required for the coking.
Another
The object of iny invention is to combine the good qualities of both systems and to
produce a larger percentage of hard coke capable of bearing the burden in a blast
furnace than it is possible to obtain in the ordinary bee-hive oven. It has also for its
object to still further reduce the time required for the coking operation.
incidental advantage of my process is that valuable bye-products may be obtained.
The process of my invention consists essentially in effecting the coking operation by
the passage, through the charge of coal, of hot gaseous products of combustion which
are thus brought into direct contact with the charge, thereby forming a hard skin on the
coke, and which also serve to expel and carry off the sulphur and other volatilizable
products inmediately they are generated instead of permitting them to remain in
contact with, and become reabsorbed by, the coke.
The operation is performed in a coking chamber, of comparatively little breadth,
situated between a combustion chamber on the one hand and a gas-collecting chamber
on the other hand, the coking chamber communicating with the combustion and gas-
collecting chambers by numerous orifices in the walls separating it from these chambers,
so that the gaseous products of combustion traverse the charge of coal to be coked
transversely in the direction of the least width of the coking chamber, on their way
from the combustion, to the collecting, chamber. The combustion chamber is
connected with a gas producer of the ordinary construction, and heated air is supplied
to the combustion chamber to effect nearly perfect combustion therein of the gases
coming from the producer furnace and to assist in forcing the gases of combustion
through the charge of coal, as above described.
The mixed gases resulting from the coking of the coal by the passage of the hot
gaseous products of combustion through it, as above described, are received in the
collecting chamber at the opposite side of the coking chamber and may be burnt
therein with an admixture of air and so assist the coking process by the heat thereby
produced. Or the said gases may be carried off and treated as in gas-works for the
extraction of chemical products therefrom and for use as heating gases.
The coking chamber preferably has an inclined floor leading down to a door in
the front end of the chamber, at which the coke may be withdrawn in the form of a
solid block.
•
I find that by my process the coking operation may be conducted at a lower
temperature than in the beehive form of oven with a consequent economy of working
and increase of durability of the apparatus.
The preferred form of apparatus wherein this process is carried into practical effect,
is represented in the accompanying drawings, forming part of this specification, in
which Figure 1 is a longitudinal sectional elevation of the coke oven (on line 1-1
Figure 3) and Figure 2 is a cross-sectional elevation of the same (on line 2-2

page_text: Figure 1) Figure 3 is an end elevation. Figure 4 is a horizontal section (on
line 3-3 Figure 1) of the doors of the coking chambers. Figures 5 and 6 are
respectively a part-sectional elevation and a longitudinal section of the preferred form
of furnace or gas producer for use in connection with the improved coke oven.
Similar letters of reference indicate like parts in all the figures.
A is a gas producer, communicating, by a flue A', with a combustion chamber B.
DD, DD, are coking chambers and CC gas collecting chambers, the combustion
chamber B being preferably placed between two coking chambers or sets of coking
chambers. The gas producer A is of the ordinary construction and fitted with the
<
"
usual appliances for generating what is known as producer' gas which is
conveyed to the lower part of the combustion chamber B by the flue Al where it
meets a current of hot air introduced through the flues A2 for the purpose of effecting
almost complete combustion of the "producer" gas in the chamber B.
Each coking chamber D is in the form of a flat parallelopiped, the roof and floor
being inclined at a pitch of about 30°. It is of approximately equal length and height
but of relatively small breadth, the latter being only about one-tenth of the height.
These are the preferred dimensions, but I do not limit myself to any particular
proportions the most important dimension being the breadth. This obviously
depends on the permeability of the stratum of coal by the gases of combustion, which
may vary according to the kind of coal to be coked and the size of the pieces, it being
apparent that the interstices between small coal will be much sinaller than between
large lumps and therefore that a stratum of the former might be less permeable than
one of the latter, other conditions being the same. I find that a good working
dimension for the breadth of the coking chamber for coking what is known as
smudge" or "duff" to be about one foot, although this might be increased up to
eighteen inches when coking rough slack.
66
Two coking chambers D D are preferably set back to back separated by a division
wall E, each pair of coking chambers D D being situated between the combustion
chamber B and gas-collecting chambers C. The combustion chamber B is common
to the coking chambers or pairs of coking chambers at either side, with which
it communicates by orifices b in the intermediate walls Each set of coking
chambers D D¹ cominunicates with the adjacent collecting chamber C by orfices c in
the intermediate walls, so that the products of combustion in passing from chamber B
to chambers C will pass across chambers D D and traverse the stratum of coal
therein contained. The orifices bc are of such size that pieces of coal will not be
liable to enter and choke them, and they may be conveniently formed either by using
perforated lumps or by leaving all the vertical joints between the bricks from the
sole to the sboulder open to the extent of about half an inch in breadth, the
brickwork above the shoulder d' being solid.
The coking chamber, or, in the example illustrated, each set of coking chambers D D1,
is surmounted by a charging mouth or hopper F common to the two chambers D Di
being situated immediately over the division wall E which extends only high enough
to separate the mass of coke in the two chambers D D into two blocks without inter-
fering with the free charging of both chambers from the one mouth F. This mouth
is closed by a cover, to prevent the escape of gas.
In order to enable the coke to be removed en bloc" and therefore with little
waste and labor in discharging when the operation is terminated, the floor d of the
coking chamber D is inclined at an angle as above mentioned so that it will 'slope
downwards from the point immediately beneath the charging mouth F to the front
end at which is situated a discharging aperture extending the full width and height
of the coking chamber. This inclination of the floor favors the withdrawal of the
coke which may be easily made to slide out in the form of a coherent mass and with
little, or no, breakage.
When using a contracting coal the side walls of each coking chamber are formed
with a ledge or shoulder at at a slightly greater pitch than the inclined floor d, and
upon these ledges the upper part of the charge, which fills the coking chamber
nearly up to the roof, rests, and so seals the passage left by the contraction in bulk of

page_text: the coal in the operation of coking and prevents the gases of combustion passing
round, instead of through, the charge.
For
The discharge apertures of the coking chambers are closed during the coking
operation by doors G G hinged at one side, the lower door G closing the aperture up
to the level of the ledges . The upper door is independent of the lower door and
serves to give access to the oven (when the lower door is closed) for levelling the
charge, besides facilitating the sealing of the lower door as hereafter described
the purpose of sealing the doors the brickwork is rebated at the sides of the aperture,
as shewn at d² Figure 4, to a depth rather less than the thickness of the lining of the
door so ns to leave a vacant space between the door and the brickwork. Into these
spaces a packing of dry sand, lime, or other suitable pulverulent material, is easily
run after the lower door G is closed. This pulverulent packing absorbs tar from the
gas and quickly makes a gas-tight joint, thereby avoiding the troublesome operation
of luting in the ordinary way. The upper door (+¹ is received in a similar rebate and
is made gas-tight in the same way, a space g¹ being left between the top flange of the
door and the brickwork, into which sand etc., is run, as well as into the side spaces.
The joint between the doors is made gas-tight by the same means (sand, etc.) poured
in a hopper g carried by the upper door and resting on a plate 93 on the top of the
lower door and so filling the joint. The bottom edge of the lower door G is seated in
a similar manner.
The perforated walls of the coking chambers are preferably strengthened by leaders
or cross-ties H of firebrick crossing the combustion and gas-collecting chambers B, C,
and connecting the walls together in pairs, as shewn in Figure 1.
ور
In order to ensure the efficient heating of the charge from below, the "producer
gas has access to the space beneath the floor d (which is of firebrick) by orifices in
C
the lower part of the walls of the combustion chamber B, as shewn in Figure 1, hot
air being also admitted to the same space to effect nearly perfect combustion.
The mixed gases collected in chambers C having absorbed fresh carbon, by
traversing the charge, may be burnt therein with an admixture of more air and so
assist the coking process; or they may be conveyed away and treated as in gas-works
for the extraction of chemical products therefrom and for use as heating gases.
Sight holes fare provided to enable the state of combustion in chamber B to be
inspected during the operation, it being necessary to so regulate the admission of bot
air that there shall be no excess of oxygen which would cause the combustion of the
coke. To avoid this the supply of air should be so limited that there will be a slight
deficiency of oxygen and the combustion of the "producer" gases will be nearly,
but not quite, perfect which is denoted by their presenting a slightly smoky
appearance.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manuer the same is to be performed, I declare that what
I claim is:
The herein-described process of making foundry coke by the passage, transversely
through the charge of coal to be coked, of hot gaseous products of combustion whereby
the hot gases are brought into direct contact with the charge and the volatilizable
products distilled off are carried away as they are generated, as specified.
Dated this 28th day of April 1890.
F. J. JONES.
By A. M. & Wm. Clark,
53, Chancery Lane, London. Patent Agents.