IMPROVEMENTS IN THE DESTRUCTIVE DISTILLATION OF BITUMINOUS SUB- STANCES, AND IN THE APPARATUS OR MEANS EMPLOyed therefoR
Year: 1876

page_text: LETTERS PATENT to William Young, Alexander Neilson, and Alexander Young,
all of Clippens, in the County of Renfrew, North Britain, for the Invention
of "IMPROVEMENTS IN THE DESTRUCTIVE DISTILLATION OF BITUMINOUS SUB-
STANCES, AND IN THE APPARATUS OR MEANS EMPLOyed therefoR."
Sealed the 19th December 1876, and dated the 9th October 1876.
PROVISIONAL SPECIFICATION left by the said William Young, Alexander
Neilson, and Alexander Young at the Office of the Commissioners of Patents
on the 9th October 1876.
"
WILLIAM YOUNG, ALEXANDER NEILSON, and ALEXANDER YOUNG, all of Clippens,
in the County of Renfrew, North Britain. IMPROVEMENTS IN THE DESTRUCTIVE
DISTILLATION OF BITUMINOUS SUBSTANCES AND IN THE APPARATUS OR MEANS
EMPLOYED THEREFOR."
This Invention relates to improvements in the destructive distillation of shale,
coal, and similar bituminous substances.
The first part consists essentially of improvements on the process for employing
the residue of coke for the purpose of producing, by the combustion of the fixed
carbon it may contain, sufficient heat or a portion of the heat necessary for the
destructive distillation of the bituminous substance, and for which Letters Patent
were granted to William Young, Peter Brash, and Andrew Scott, dated the 21st
day of August, 1872, and numbered 2487.
In that process is described a method of sealing or excluding the atmospheric air
from the retort or distilling vessel by employing a steam jet or other exhausting
device to draw off the products of distillation as they are formed, condensing out
the oil vapours, and returning the permanent gases back into the open end of the
retort.
It has been found, in carrying this process out in practice that the gases, under
certain unfavourable circumstances, do not perfectly exclude the atmospheric air,
nor yet prevent oil vapours from finding their way into the combustion chamber
for instance, in gusty or windy weather the current of gases is liable to be
deranged, the oil vapour being puffed out at the bottom into the combustion
;

page_text: chamber, and again, when the shale refuse in the lower half of the retort happens
not to be properly arranged, there is a tendency in the gases to be blown down one
side of the open end of the retort, and a portion of the products of combustion
drawn up the other side of the retort in their stead, thus injuring the oils.
Another source of considerable loss experienced in conducting that process results
from the difficulty in regulating the quantity of ash to be drawn from the com-
bustion chamber, because if it be too small the proper charge cannot be got into the
retort, and on the other hand, if too much ash be taken from the combustion
chamber the shale or other bituminous substance sinks out of the retort before the
volatile matter is distilled out.
The first part of this Invention has for its object the remedying of these defects,
and this we accomplish by the following arrangement:-The lower end of the
retort is considerably contracted, and on it there is fixed a box or chest having a
hole through it corresponding to the opening in the retort. Into this chest is
placed a plate made of iron, fire-brick, or other suitable material. This plate is
connected to a rod passing through the cover on this chest, and can be pushed in
to close the opening in the recess corresponding to the bottom of the retort.
Underneath this box or chest, and immediately over the combustion chamber there
are placed fire-clay blocks also having a hole pierced through them corresponding
to the bottom of the retort, and there is also provided in them a recess, in which is
placed another sliding plate of fire-brick or other fire-resisting substance.
The gas used to exclude the atmospheric air is introduced between those plates,
and as it has at all times a free space between the plates it spreads itself equally
over the whole surface of the bottom of the upper plate and totally excludes atmo-
spheric air or products of combustion. Those plates also equalize the gas current
and prevent back puffing of the hydrocarbon vapours by the wind or other causes.
In order perfectly to seal the bottom of the retort with gas it is necessary that a
very considerable portion of the saturated gas be passed or drawn up into the
retort, which, mixing with the oil vapour, is apt to carry forward mechanically
suspended a portion of the oil in a finely divided state, and which is returned into
the bottom of the retort and partly lost.
To prevent this inconvenience we, under the second part of our Invention, employ
steam, either as a substitute for the gas or mixed with it in large proportions
which can be conveniently and economically effected by fixing the steam jet for
causing the circulation of the gas on to the pipe just before it enters the valve chest
or bottom of the retort. The steam thus introduced condenses with the condensing
oils, and prevents them floating forward.
As the retort is completely filled at each charge with the substance to be distilled
and the refuse coke is also emptied completely from the retort into the combustion
chamber no skill is required in regulating the charge, and therefore the retort is
always doing its full complement of work, and consequently the cost of plant is
diminished per ton of shale or other substance distilled.
As the shale refuse, or coke in many cases contains a very small quantity of
fixed carbon, it will keep up combustion only for a limited time, after which it
becomes essential to use coal or other fuel.
The third portion of our Invention relates then to the hastening of the distilla-
tion, and more especially downward distillation which we accomplish by making
the retorts with a much narrower or thinner space between the sides, consequently
containing a thinner layer of shale or bituminous substance which is much more
quickly acted upon, and which allows of it being more quickly exhausted of its
volatile matter, and the coke dropped into combustion chamber to keep up the
heat. For a very poor shale or coal having little carbon in its coke we find a space
of 6 inches to answer very well, and in no case do we care about exceeding 12
inches. The retort may have a considerable breadth and height to make up for
the extra thinness.
The fourth part of this Invention relates to a method of facilitating the emptying
of the refuse or ash from the combustion chamber. This we accomplish by employ-

page_text: ing a false bottom or set of sliding bars or a plate which can be withdrawn; the
combustion chamber or a portion of it being either hung on beams or supported on
columns so that wagons may be run underneath to receive the ash on the plate
being withdrawn. On the other hand, when the bituminous substance contains
so little carbon that it cannot be used as fuel, or again, if it contains more than
sufficient to produce the distillation we employ a modification of the arrangement
herein-before described. The retorts are the same in form and dimensions, but
instead of having a chest fixed on their lower end the retort is provided with a
door similar to that in ordinary use. It is also provided with a furnace so arranged
that it can either be fired wholly with coal or other fuel, or a portion of the charge
of coke from the bituminous substance when rich in carbon may be drawn down
into the furnace, the remainder being discharged direct from the retort and
quenched, or when the coke is valueless the whole may be drawn directly from the
retort for removal.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Young, Alexander Neilson, and Alexander Young in the
Great Seal Patent Office on the 7th April 1877.
WILLIAM YOUNG, ALEXANDER NEILSON, and ALEXANDER YOUNG, all of Clippens,
in the County of Renfrew, North Britain, "IMPROVEMENTS IN THE DESTRUCTIVE
DISTILLATION OF BITUMINOUS SUBSTANCES, AND IN THE APPARATUS OR MEANS
EMPLOYED THEREFOR."
Our said Invention which relates to improvements in the destructive distillation
of shale, coal, and similar bituminous substances consists,―
Firstly, In improvements on the process for employing the residue of coke to
produce, by the combustion of the fixed carbon it may contain, sufficient heat or a
portion of the heat necessary for the destructive distillation of the bituminous
substance, and for which Letters Patent were granted to William Young, Peter
Brash, and Andrew Scott, dated the 21st day of August 1872, and numbered 2487.
In the Specification filed in pursuance of the said Letters Patent is described a
method of sealing or excluding atmospheric air from the retort or distilling vessel
by employing a steam jet or other exhausting device to draw off the products of
distillation as they are formed, condensing out the oil vapours, and returning the
permanent gases back into the open end of the retort.
It has been found, in carrying this process out in practice, that the gases, under
certain unfavourable circumstances, do not perfectly exclude the atmospheric air,
nor yet do they prevent the oil vapours from finding their way into the combustion
chamber; for instance, in gusty or windy weather the current of gases is liable to
be deranged, the oil vapours being puffed out at the bottom into the combustion
chamber; and again, when the shale refuse in the lower half of the retort happens not
to be properly arranged there is a tendency in the gases to be blown down one side
of the open end of the retort, and a portion of the products of combustion drawn up
the other side of the retort in their stead, thus injuring the oils.
Another source of considerable loss experienced in conducting the said process
results from the difficulty in regulating the quantity of ash to be drawn from the
combustion chamber, because if the quantity drawn is too small the proper charge
cannot be got into the retort, and on the other hand, if too much ash be taken from
the combustion chamber the shale or the bituminous substance sinks out of the
retort before the volatile matter is distilled.
The first part of our said Invention then has for its object to remedy these
defects, and this we accomplish by the following arrangements:-The lower end of
the retort is considerably contracted, and on it there is fixed a box or chest, having
a hole through it corresponding to the opening in the retort. Into this chest is
placed a plate made of iron, fire-brick, or other suitable material, which plate is

page_text: connected to a rod passing through the cover on the chest, and is capable of being
pushed in to close the opening in the recess at the bottom of the retort. Under-
neath this box or chest, and immediately over the combustion chamber, there are
placed fire-clay blocks, also having a hole pierced through them corresponding to
the bottom of the retort, and there is also provided in them a recess, in which is
placed another sliding plate of fire-brick or other fire-resisting substance.
The gas used to exclude the atmospheric air is introduced between those plates,
and as it has at all times a free space between the plates it spreads itself equally
over the whole surface of the bottom of the upper plate, and totally excludes
atmospheric air or products of combustion. These plates also equalise the gas current
and prevent the back puffing of the hydrocarbon vapours by the wind or other causes.
In order perfectly to seal the bottom of the retort with gas it is necessary that
a very considerable portion of permanent gas be passed or drawn up into the
retort, which mixing with the oil vapours is apt to carry forward, mechanically
suspended, a portion of the oils in a finely divided state, which portion is returned
into the bottom of the retort and partly lost.
To prevent this inconvenience we, under the second part of our Invention,
employ steam, either as a substitute for the gas or mixed with it in large propor-
tions. When the steam is to be mixed with the gas this can be conveniently and
ecconomically effected by fixing the steam jet for causing the circulation of the gas
to the gas pipe before it enters the valve chest or bottom of the retort. The steam
introduced under either mode condenses with the condensing oils and prevents them
floating forward.
As the retort is completely filled at each charge with the substance to be distilled,
and the refuse coke is also emptied completely from the retort into the combustion
chamber, no skill is required in regulating the charge, and therefore the retort is
always doing its full capacity of work.
As the shale refuse, or coke in may cases contains a very small quantity of fixed
carbon, it will keep up combustion only for a limited time, after which, with the
retorts as at present constructed, it becomes essential to use coal or other fuel.
The third portion of our Invention relates then to the hastening of the distilla-
tion, and more especially downward distillation, by making the retorts with a
much narrower or thinner space between the sides, consequently containing a
thinner layer of shale or bituminous substance. The shale or bituminous
substance is thus much more quickly acted upon and exhausted of its volatile
matter, and the coke is dropped into the combustion chamber at shorter intervals
of time to keep up the heat. In this case when the shale is rich enough in car-
bonaceous matter the resulting coke may be sufficient to produce all the beat
necessary for the distillation, and in cases where the shale is poor in carbon then a
less amount of auxilliary fuel is required. For a very poor shale or coal having
little carbon in its coke we find a space of six inches to answer very well; and in
no case do we find it advantageous to exceed about twelve inches. The retort
may have a considerable breadth and height to provide sufficient capacity which
would be otherwise reduced by the thinness.
Over and above the advantage of a more perfect application of the carbon in the
residual coke this thinning of the retorts producing a rapid distillation is a great
economy of plant as it enables a retort of a given capacity to do much more work.
And in order that our said Invention may be properly understood we now
proceed more particularly to set forth the system, mode, or manner in or under
which the same is or may be used or practically carried into effect, reference being
had to the annexed Sheets of Drawings and to the letters and figures marked
thereon, that is to say,-
On the Sheet of Drawings hereunto appended Figure 1 is a vertical section of a
retort constructed in accordance with our said Invention for the destructive distil-
lation of shale and other bituminous substances; Figure 2 is in part a front
elevation and in part a transverse section of a bench of such retorts; and Figure 3
is a sectional plan of the same.

page_text: The retort is first heated by firing with coal placed in the combustion chamber A,
the sliding plates B and C being kept closed. The products of combustion pass by
the flue or port D into the space E, around the retort F, and afterwards pass away
by the flue G, Figure 2, to the main flue H, leading to the chimney, the draught
being regulated by the dampers I so soon as the proper temperature is attained.
The shale or other bituminous substance is charged into the retorts F by the
hopper doors J, and the doors are then replaced and luted. So soon as volatile
hydrocarbonacious matter appears at the low opening or aperture P in the fire-clay
block K an exhaust is produced from the retorts by the outlet (N) to the main O by
means of a steam jet or other mechanical exhausting or pumping arrangement. The
amount of this exhaust must be considerably more than sufficient to draw off all
the volatile products resulting from the bituminous substance undergoing distilla-
tion, this being necessary to ensure that none of the products of distillation shall at
any time find their way into the furnace.
It will be evident that, as the sliding plates B, C, in the chest L, are not air or
gas tight, a portion of whatever gas is externally surrounding those plates will be
drawn up into the lower end of the retorts F. If the products of combustion were
thus allowed to be drawn up they would injure the products of distillation. To
prevent this the permanent gases which are always produced when shale or other
similar substances are distilled are returned from the terminal of the condensers
back by the pipe M into the chest L, where they are distributed over the bottoms of
the retorts in the space between the tar plates B, C. Those gases being principally
hydrocarbons or other gases, containing no free oxygen, in being drawn up through
any open spaces around the plates B into the retorts F do not injure the oily
products of distillation.
Instead of the permanent gases from the terminal condensers being employed a
grating may be placed at the back of the combustion chamber A, and part of the
carbonic oxide or other gases containing no free oxygen drawn off through the said
grating and conducted to the pipe M, or suitable gases from any independant
source of gas supply may be so used.
To ensure a perfect seal, and to prevent air or products of combustion from the
combustion chamber A, entering the retorts, it is necessary to introduce a con-
siderable excess of gas over what is drawn up into the bottom of the retorts, and
that a portion, however small, should be always passing down through the spaces
around the lower plates C into the apertures P in the fire-clay blocks K.
So soon as the bituminous substance has become exhausted of its volatile matter
the sliding plates B and C are withdrawn by the attendant by means of a bar
provided for the purpose, and seen in enlarged detail at Figure 4, one end of which is
formed with a book which is placed in one of the recesses of the rack x and acts
as a fulcrum. The lower part of the bar bears against cross heads on the ends of
the rods attached to the sliding platos, so that when the bar is moved outwards on
the rack a leverage sufficient to withdraw the sliding plates or to return them to
position is obtained. When withdrawn the residue or coke is dropped into the
combustion chamber, the carbon thereof produces the heat, or a portion of the heat
necessary for the distillation of a fresh charge of bituminous substance, which
immediately the sliding plates B, C, have been replaced is introduced into the
retort.
As the carbon in the residue or coke resulting from the shale and similar
substances (which it is intended by this Invention to utilise) keeps up the heat or
will burn only for a limited time, it is evident that the rate of distillation must (if
possible) be such that the distilling and consumption of carbon in the coker be
completed nearly simultaneously, for if the distillation be not completed when the
carbon in the coke is consumed, then coal or other fuel must be employed to keep
up the heat on the retorts and complete the distillation.
One of the main features of this Invention consists in so constructing the retorts
that the bituminous substance is presented to the heat in thin layers, so that the
heat may act rapidly upon it and produce complete distillation by the time, or

page_text: slightly before the time, that the carbon in the residue or coke from the previous
charge is consumed. Of course there are some shales containing so small a per-
centage of fixed carbon that however thin the layers of sbale may be made
sufficient heat will not be produced to complete the distillation, but the thinning of
the layers of shale and hastening the distillation will enable the complete distilla-
tion of the bituminous substance to be effected with a much smaller quantity of
auxiliary fuel.
It is to be understood that when the retort is in operation the upper sliding door
may be drawn out, as the contents of the retorts becoming wedged together in the
narrow space by the compression due to the height of the column of materials,
support themselves, thus leaving a larger free space for the gases to spread them-
selves in at the bottom of the retort than when the door is not withdrawn, at the
same time the door is not so quickly destroyed by heat.
Having now described and particularly ascertained the nature of our said
Invention, and the system, mode, or manner in or under which the same is or may
be used or practically carried into effect, we would observe in conclusion that we
are aware that narrow or thin retorts have been previously proposed, but that as
hitherto proposed to be used, economy of fuel thereby has not been effected as under
the present Invention, what then 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,-
First. Constructing and arranging retorts for the destructive distillation of shale,
coal, and other bituminous substances with their lower ends considerably contracted
and provided with a fixed box or chest L, having a hole through it corresponding to
the opening in the retort, and containing a sliding plate B, made of iron, fire-brick,
or other suitable material, for closing the bottom of the retort, another sliding
plate or block C being also provided to close the opening from the retort into the
combustion chamber A, atmospheric air and the products of combustion from the
chamber A being excluded from the retort whilst in operation by a jet of steam or
by a current of permanent gas induced into the box or chest L, and through the
retort by steam either mixed with the permanent gas (for the purposes set forth)
or separately conducted into the apparatus or by a mechanical exhausting or
pumping arrangement, substantially, as herein-before described.
Second. The retorts for the destructive distillation of shale, coal, and other
bituminous substances, with a narrow or thin space, preferably of from six to
twelve inches, the width of the space being dependent upon the amount of fixed
carbon in the coke residue resulting from the distillation of bituminous substance,
and whereby the distillation, and especially downward distillation, is hastened and
fuel economised, substantially, as and for the purposes herein-before described.
In witness wherof, I, the said William Young, on behalf of myself and
the said Alexander Neilson and Alexander Young, have hereunto set my
hand and seal this Fourth day of April, One thousand eight hundred and
seventy-seven.
W. YOUNG. (L.S.)