CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF GAS, COKE, AND OTHER PRODUCTS FROM COAL, AND IN APPARATUS FOR THAT PURPOSE
Year: 1854

page_text: LETTERS PATENT to Aristide Balthazard Bérard, of Paris, in the French
Empire, Engineer, and Chevalier of the Legion of Honour, for the
Invention of CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF GAS, COKE,
AND OTHER PRODUCTS FROM COAL, AND IN APPARATUS FOR THAT PURPOSE,"
Sealed the 9th February 1855, and dated the 23rd August 1854.
PROVISIONAL SPECIFICATION left by the said Aristide Balthazard Bérard
at the Office of the Commissioners of Patents, with his Petition, on the
23rd August 1854.
I. ARISTIDE BALTHAZARD BERARD, do hereby declare the nature of the said
Invention for "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF GAS, COKE, AND
OTHER PRODUCTS FROM COAL, AND IN APPARATUS FOR THAT PURPOSE," to be as
follows
I construct a retort of fire bricks, having its axis inclined at an angle of
forty-five degrees to the horizon, or at a greater or lesser angle if preferred.
The retort is of the form of a truncated cone, being not truly cylindrical, but
somewhat larger in diameter at the lower end, for the purpose of facilitating
the discharge of the coke, as herein-after mentioned. This retort is made of
'sufficient size to contain four or five tous of coal (more or less), and it is closed
at the top and bottom by sliding doors. A pipe of sheet iron perforated with
holes is placed in the axis of the retort. This pipe is closed at the lower end
and open at its upper end, which enters the open end of a bent pipe which

page_text: passes through the side of the retort just below the upper sliding door. This
pipe serves for conveying the gas from the retort to a vessel or hydraulic main
in connection with an aspirator or exhausting apparatus, by which the gras
is
drawn from the retort and forced through purifiers, &c. into a gasometer.
Another passage serves to convey the gas into the furnace which heats the
retort by means of flues carried round it. The gas passages are provided with
valves, so that the gas may be directed to the furnace or to the gasometer at
pleasure. A cylindrical vessel of plate iron, of somewhat greater capacity
than the retort, is mounted on a carriage in an inclined position, correspond-
ing to the inclination of the retort. This vessel can be brought upon its
carriage under the lower door of the retort, on opening which the coke in the
retort will drop into this vessel, which I call the extinguisher. The extin-
guisher is then wheeled away and closed by a lid. Its sides are made double,
and the space is filled with water, a portion of which is converted into steam
by the hot coke, and this steam is conducted into the interior of the extin-
guisher, and speedily extinguishes the coke. The coke may then be conveyed
in the extinguisher to any convenient place, or delivered into wagons. A piston
may be fitted into the extinguisher, for the purpose of gradually lowering the
mass of coke into it in lieu of allowing it to fall in; the retort is charged by
tipping the charge of coal into it from a wagon, after having placed the per-
ferated sheet-iron pipe in its centre. The distillation is then carried on, and
the gas and volatile products are drawn away by the aspirator, which is pro-
vided with a regulating float or apparatus to regulate its action, so that there
may be as little tendency as possible for gas to escape or air to enter the
retort at any leak or part not perfectly cloved or luted. The gas being taken
from the centre of the mass of coal by means of the perferated tube, is
removed from the action of the heat as it is formed, and at the same time, if
any air should be drawn in, the oxygen of this air is consumed before it can
penetrate through the mass of coal to mix with the gas, and thus the danger
of obtaining a mixture of air and gas is avoided; when all the rich gas and
volatile products have passed off, they are succeeded by a poorer gas of less
illuminating power. The valves are then moved so as to direct this gas into
the furnace, where it assists in heating the retort. After this gas has passed
off, the perforated pipe is withdrawn through au aperture in the lower door,
which is afterwards closed, and the coke is kept for some time in the hot retort;
it is then discharged into the extinguisher, as above mentioned. Two or more
of these retorts may be built together, and the furnaces may all communicate
with one common flue leading to a chimney. A second flue may be placed
parallel to the first, with communications between them, and a separate damper

page_text: to each flue. In the second flue I place a steam boiler, and the generation of
steam may be regulated by means of the two dampers. The otherwise
waste heat of the furnaces thus serves for generating steam, which may be
employed to drive a steam engine for working the aspirator, or for other
purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Aristide Balthazard Berard in the Great Seal Patent Office
on the 22nd February 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARISTIDE
BALTHAZARD BERARD, of Paris, in the French Empire, Engineer, and
Chevalier of the Legion of Honour, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of August, in the year of our:
Lord One thousand eight hundred and fifty-four, in the eighteenth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Aristide Balthazard Bérard Her special licence that
1, the said Aristide Balthazard Bérard, my executors, administrators, and
assigns, or such others as I, the said Aristide Balthazard Bérard, my
executors, administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term therein.
expressed, should and lawfully might make, use, exercise, and vend, within
the United Kingdoin of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "CERTAIN IMPROVEMENTS IN THE MANUFACTURE
OF GAS, COKE, AND OTHER PRODUCTS FROM COAL, AND IN APPARATUS FOR THAT
PURPOSE," upon the condition (amongst others) that I, the said Aristide
Balthazard Bérard, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Aristide Balthazard Bérard, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Drawings, and to the figures and letters marked thereon, that is to say:-

page_text: In the ordinary modes of distilling or carbonizing coal for the purpose of
obtaining coal gas as the principal product, or for obtaining coke adapted for
metallurgic operations, or for use in locomotive engines, some of the products
are either lost or obtained of inferior quality, or at considerable cost. The object
of the present Invention is to obtain all or nearly all the products which the
coal is capable of yielding of superior quality and in an economical manner.
For this purpose it is requisite that the coal should undergo distillation in a
close vessel with little or no admixture of air, and consequently the heat must
be applied to the exterior of the vessel. Moreover, for the sake of economy,
and to obtain a good quality of coke, it is desirable to operate upon large
masses of coal, and to be enabled to charge and discharge the vessel or oven
as quickly as possible, so as to avoid loss of heat, and also to perform the
operations as simply and with as little labour as possible.
In order to realise the most important condition of operating upon large
masses with little or no access of air, new means are required, as it is not
practically possible to construct large ovens so as to continue impermeable
to infiltrations of air at the junctions of the doors or at the joints of the
brickwork.
gases
When a mass of coal is exposed to heat it may be observed that the volatile
and gascous products are driven away from the surface to which the heat is
will
applied, so that if the coal be surrounded on all sides by the heat, the
be driven towards the centre of the mass. In accordance with this principle,
I have succeeded in advantageously collecting the volatile and gaseous products
from a considerable mass of coal, by establishing the outlet for the gas in the
centre of the mass. The apparatus herein-after described is constructed in
accordance with the requirements herein-before mentioned.
Figure 1, Sheet I. of the accompanying Drawings, is a vertical section of the
apparatus and Figure 2 is a sectional plan of the same at the level of the
furnace; Figure 3 is an elevation of the back of the apparatus; Figure 4 is a
view of the lower door of the retort; and Figure 5 is a transverse section of
the retort, as herein-after described. The same letters indicate similar parts in
all the figures. A is a cylindro-conical oven or retort constructed of fire clay,
and having its axis inclined at an angle of forty-five degrees to the horizon.
The angle of inclination may be varied, but should never be less than forty
degrees, nor more than sixty degrees. The upper and lower ends of this
retort are closed by sliding doors a and b, which serve for charging and dis-
charging it. A sheet-iron pipe B, made slightly conical, is placed in the axis
of the retort, and passes through the lower door b. The upper extremity of

page_text: this pipe enters a fixed cast-iron pipe C, which serves as a support and pro-
longation of the pipe B; the lower extremity of the pipe B is closed by a
plate. The pipe B is perforated at its sides from the top to within about
eighteen inches of the lower door. The perforations are sufficiently large to
give a free passage to the gas without allowing the fragments of coal to pass
through.
The lower door bis closed, and the pipe B is inserted in its place, and the
upper door is opened. The whole charge of coal is brought in a wagon e
running on a railway, and capable of being tipped up. The charge of coal is
thus shot into the retort at one operation, and almost instantaneously. The
upper surface of the coal is rammed or levelled so as to fit as close as
possible to the upper door, which is then closed. The operation of charging is
then completed. The retort is of sufficient capacity to contain at least a
ton of coal, and I prefer to make it large enough to contain four or five tons
of coal.
The retort A is heated by a fire made on the fire bars d, and at certain
periods by the poor gas or gas of small illuminating power, as herein-after
described. The products of combustion ascend in the flue D, and pass through
several small openings into the flues E, E, E, EU, through which they
descend to the lower end of the retort, where they again pass through several
small passages into the flues F, F, F, which conduct them again to the upper
end of the retort, whence they pass through the flues G and G' into the general
flue 1, which serves for several of these retorts, and communicates with a
chimney. This general flue H is in two stages or compartments separated by
an arch e, in which are a number of openings. A steam boiler or generator I
may be placed in the lower stage or compartment of the flue. At the place
where the two compartments communicate with the chimney are two dampers
or slides, by means of which either compartment may be wholly or partially
closed. The generation of steam is thus easily regulated, for, by closing the
damper of the upper compartment and opening that of the lower one, the
products of combustion are directed through the lower compartment so as to
heat the boiler. If it be desired to check the generation of steam, the damper
of the upper compartment is opened, and that of the lower one is closed.
The products of combustion then pass along the upper compartment of the flue
without descending into the lower compartment. The admission of air under
the grate is regulated by a slide or register in a door, which is fitted to
and closes the ash-pit under the grate.
By these arrangements, the heat produced by the fuel consumed is turned
to good account, as the products of combustion, after heating the retort, com-

page_text: municate a further portion of their heat to the steam boiler. All sides of the
retort are heated by the flues to a proper temperature for the production of gas.
The doors may also be heated by conducting a small portion of the products of
combustion through passages formed in the doors.
The gases are collected in the following manner-The retort and the sur-
rounding brickwork being already heated by previous operations, and the
pipe B being in its place, and the charge of coal having been introduced,
the coal will immediately commence giving off its gas, which passing towards
the centre of the mass of coal, enters the pipe B through its numerous per-
forations. However, the thickness of the mass of coal which the gas has to
traverse will offer a certain resistance, which tends to cause the gas to escape
at any of the joints of the brickwork, or of the doors which may be defective.
To obviate this defect, an exhausting machine (herein-after described) is used
to draw the gas out through the pipe B. If the exhauster is regulated to
withdraw the gas at the same rate as it is formed, the whole of the gas will
be collected. If the action of the exhauster is less than the gas produced,
the gas will be found to escape at any leaky joints, showing that the action of
the exhauster requires to be increased. If, on the contrary, the action of the
exhauster is too great, a portion of air will be drawn in; but as this air has to
traverse a mass of coal or coke at a high temperature, its oxygen is converted
into carbonic oxide before reaching the pipe B. Thus, in place of the oxygen
of the air becoming mixed with the gas, a small quantity of carbonic oxide
may be introduced, which has scarcely any injurious effect. This results from
the mode of taking the gas from the centre of the mass of coal. However,
the action of the exhauster may be so regulated, as herein-after described,
as to prevent any appreciable loss of gas or any sensible admixture of
foreign gases.
meter.
The gases distilled from the coal pass from the perforated pipe B, through
the pipe C, into a box K. L. is a pipe which serves to put the box K in
communication with the exhauster, by which the gas is driven into a gaso-
M is another pipe, which serves to convey the poor gas which is pro-
duced during the latter part of the operation to the furnace, where it is
burned, and assists in heating the retort. The end of each of the pipes L
and M, where it enters the box K, is covered with an iron bell or cap, which
dips in a portion of water or tar contained in the box, and thus forms a simple
hydraulic valve, by raising or lowering which the gas may be directed to the
furnace or to the exhauster, and the amount of the exhaustion may also be
regulated. The valve of the pipe M being lowered, and that of L raised, the
communication is established with the exhauster. The gases pass down the

page_text: pipe L, which dips in water contained in a second box or washing vessel N,
and thence through a pipe O into the main pipe P, which conducts it to the
exhauster, by which it is driven into the gasometer.
The carburetted hydrogen gases are not the only volatile products of the
distillation, which also comprise a considerable quantity of ammoniacal water
and volatile essential oils, tar, &c. All these products pass with the gases into
the box K, in which a considerable portion of them condense, forming ammo-
niacal liqour and tar. These liquid products collect in the bottom of the
box K, but as their quantity increases, the excess overflows by the syphon K¹.
A similar overflow syphon N is provided for the washing vessel N. The
liquids which escape at N' and are conveyed by a trough Q to one
common reservoir.
The gases may be cooled by a current of cold water, either introduced
into the boxes K and N, or conducted round the exterior of the pipes.
The gases rich in carbon, and of great illuminating power, are liberated
during the first part of the operation, and conducted to the gasometer. The
poorer gases, which then succeed, are directed into the furnace, and serve to
heat the retort. When the production of gas ceases, the two hydraulic valves
are closed, and the pipe B is drawn out of the retort through the opening in
the centre of the lower door b; this opening is inmediately closed by an iron
plug, luted with fire clay. The coke produced in the retort is then left for
some hours in this state, so that it may absorb or decompose the last portions
of tar which may remain in it.
The retort is then discharged in the following manner:-
A cylindrical extinguishing vessel R, of somewhat larger capacity than the
retort, is constructed of two concentric cylinders of sheet iron, placed an inch
or two apart, and connected by stays. The double casing thus formed is filled
with water through a tube, with a funnel and stop-cock fixed on the top. A
pipe S serves to convey the steam which is generated in the double casing
into the lower part of the extinguisher. The lower end of the extinguisher is
closed by a plate, having a central hole, through which passes the rod of a
piston The upper end may be closed by a moveable door. The extin-
guisher is supported on trunnions, placed a little below its centre of gravity;
and it is kept in its position by means of a chain g attached to its lower end,
and wound on a roller or windlass . The whole is mounted on a carriage i,
which runs upon a railway.
When it is required to discharge the coke from the retort, the extinguisher
is advanced under it, so as to form a continuation or prolongation of the retort.
The upper door of the extinguisher being open, and the piston raised to its

page_text: highest position, the lower door b of the retort is opened by means of a moveable
erane or windlass or similar means. The mass of coke in the retort then slides
down into the extinguisher, and the rapidity of its descent is regulated by
lowering the piston f, so as to avoid the breaking of the coke. As soon as all
the charge is in the extinguisher the door is closed, and the extinguisher is
drawn away, and its upper door is closed. The heat of the coke converts a
portion of the water in the double casing into steam, which passes through the
pipe S into the lower part of the extinguisher, and rises through the coke,
driving out the air, and rapidly extinguishing the coke, and at the same time
expelling the sulphur from it. The extinguisher also serves as a vehicle for
the transport of the coke, which may be shot out from it into wagons and
carried away. The loss produced by the breaking of the coke into dust, which
takes place in the ordinary means of discharging, is thus reduced. One of
these extinguishers is sufficient for several retorts.
! The coke thus obtained is of excellent quality and large in quantity; being
produced sufficiently slowly, and in a considerable mass in a closed space,
where it cannot dilate, it is hard and solid, and more dense than coke obtained
in the ordinary manners. As soon as the coke is withdrawn from the retort,
and the lower door is closed, the upper door is opened, and the pipe B is
inserted in its place, and a fresh charge of coal is introduced, and the opera-
tion proceeds as before, The discharging and recharging is thus effected with
great rapidity.
I will now proceed to describe the means of exhausting the gases and driving
them into the gasometer. Various arrangements of apparatus may be employed
so as to fulfil the two essential conditions of regularity of motion, and a constant
degree of exhaustion, whatever may be the resistance to the exhauster, or the
quantity of gas to be passed through it. The following arrangements are
adapted for the purpose:-
Figure 6, Sheet II., is a vertical section, and Figure 7 is a plan, of the
exhausting apparatus. Two bells or gasometers A and A' are arranged so as
to be capable of moving up and down in two vessels or tanks K, K', which are
partially filled with water. The two bells A and A' are moved by a beam L
which is driven by a connecting rod M, jointed to a crank or pin on the wheel
N. The wheel N is driven by a pinion O on the crank shaft of a steam engine,
the cylinder of which is shewn at Q. In each of the tank's K, K, are two
pipes marked respectively B, B, and B, B, of which the pipes B and B
serve as suction pipes, and the pipes B and B serve as force pipes. The
upper end of each of the pipes is provided with a series of valves placed verti
cally, and capable of opening and closing with very slight variations of pressure.

page_text: Figure S is a transverse vertical section of the bell A', and tank K', showing
the pipes B and B111, with their valves. The valves of the pipes B and B11
are made to open towards the bells, while those of the pipes B and B open
inwards to the pipes. The two suction pipes B and B unite in one pipe at
the point C, and this pipe is the prolongation of that marked P, in Figures
1, 2, and 3, Sheet I., and which serves for several retorts. In a similar
manner the two force pipes B and B unite in one pipe at D, which conducts
the gas to the gasometer. The gas may be passed through one or more purifiers
in its course from the exhauster to the gasometer, or in its course from the
retorts to the exhauster. The pressure on the gasometer may be increased
with no other inconvenience than that of requiring more power to work the
exhauster.
The action of the two bells is alternate, so that when the bell A. ascends, and
the bell A¹ descends, the valves of the suction pipe B open, and the gas.is
At the
drawn into the bell A, while the valves of the force pipe B¹ are closed.
same time the bell A¹ is descending, and drives the gas which it contains
through the valves of the force pipe B1, while the valves of the suction pipe
B remain closed. The motion being now reversed, the gas in the bell A is
driven into the force pipe B¹, while the gas from the retorts is drawn into the
bell A1, through the pipe B. Thus one bell is always exhausting the from
the retorts while the other is forcing it-into the gasometer, and vice versa, and
a continuous action is thus maintained.
gas:
But it will
The constancy of the degree of exhaustion is obtained in the following
manner If the exhauster were always driven at the same velocity, the
quantity of gas pumped through it would be always the same, supposing the
retorts to be regulated so as to produce a constant supply of gas.
often happen that the exhaustion will require to be increased or diminished in
some of the retorts, or entirely suspended at certain times, as, for instance,
during the operation of charging the retorts. In this case, if the exhauster
works always at the same speed, the exhaustion will increase in those retorts
with which the communication remains open. This is an effect to be avoided.
It is not then the speed of the exhausting machine which requires to be uniform,
but it is the degree of exhaustion which should be uniform, and therefore the
speed of the machine should be regulated by the exhaustion. For this purpose
the suction pipe is connected by a pipe E to a regulator, which is shewn in
the plan, Figure 7, and in Figure 9, which is a transverse section of the
regulator. This regulator consists of a box or vessel of sheet iron, divided
into two compartiments F and F by a partition reaching from the top of the
vessel to within a short distance of the bottom. The compartment F is closed
B

page_text: at the top, while the compartment F¹ is open at top. The vessel is partially
filled with water. An increase of pressure in the compartment F will thus
cause the level of the water to descend in F and rise in F¹, and vice versa.
In the compartment F¹ is a float R, connected by a rod to a lever G, G', the
motion of which opens and closes a valve or cock H, which regulates the
admission of steam to the cylinder Q of the steam engine. Thus, when
the float R descends, owing to an increase in the degree or amount of the
exhaustion in the compartment F, the valve H is partially closed, so as to
check the admission of steam to the engine, and thus reduce its speed. If,
on the contrary, the exhaustion diminishes, the float R ascends, and opens
the valve H, thus admitting more steam to the engine, and increasing the
exhaustion. Thus, the degree of exhaustion is kept nearly uniform, while the
speed of the engine is variable. Various other arrangements of self-regulating
exhausters may be employed in lieu of that herein-before described.
If desired, the gases may be separated and collected in two, three, or more
distinct portions, according to the purposes for which they are required. For
this purpose it suffices to apply two, three, or more exhausters with separate
pipes and valves and gasometers. The first portion of gas which is liberated
from the coal may thus be directed into one gasometer, and the succeeding
portions into other gasometers. If desired, the whole of the gas may be
collected, instead of burning a portion to heat the retort, as herein-before
described.
Having now described the nature of my Invention, and in what manner the
same is to be performed, I wish it to be understood that what I claim is.-
Firstly, the manufacture of gas, coke, and other products from coal. by
distilling the coal in masses of not less than one ton in a cylindro-conical fire-
clay retort, having its axis inclined to the horizon at an angle of not less than
forty degrees, nor more than sixty degrees, and having in its axis a detached
or moveable perforated pipe, by which the gas is withdrawn from the centre
of the mass of coal by means of an exhauster, and which perforated pipe is
capable of being removed during the operation, as herein-before described.
Secondly, the constructing apparatus for the manufacture of gas, coke, and
other products from coal, by the combination of a self-regulating exhauster with
a cylindro-conical fire-clay retort, having its axis inclined to the horizon at an
angle of not less than forty degrees nor more than sixty degrees, and capable
of being charged and discharged as herein-before described, and furnished
with a moveable central perforated pipe for the exit of the gas, so arranged as
to be capable of being removed during the operation, and before discharging the
coke, as herein-before described. Also, the combination with such apparatus

page_text: of a cylindrical extinguisher for extinguishing the coke, with a double casing
for containing water, and supported on trunnions on a carriage, and so arranged
as to be capable of being applied to the lower end of the inclined retort, and
of being moved away when filled with coke, which may be discharged by
inclining the extinguisher, as herein-before described.
In witness whereof, I, the said Aristide Balthazard Bérard, have hereunto
set my hand and seal, this Thirteenth day of February, in the year of
our Lord One thousand eight hundred and fifty-five.
ARISTIDE BALTHAZARD BERARD. (L.S.)