IMPROVEMENTS IN THE MANUFACTURE OF ILLUMINATING GAS, AND IN THE APPARATUS EMPLOYED THEREFOR."
Year: 1875

page_text: LETTERS PATENT to Henry Aitken, of Falkuk, in the County of
Stirling, North Britain, Coalmaster, and William Young, of
Clippens, in the County of Renfrew, North Britain, Oil Works
Manager, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
ILLUMINATING GAS, AND IN THE APPARATUS EMPLOYED THEREFOR."
PROVISIONAL SPECIFICATION left by the said Henry Aitken and
William Young at the Office of the Commissioners of Patents,
with their Petition, on the 3rd August 1875.
We, HENRY AITKEN, of Falkirk, in the County of Stirling, North
Britain, Coalmaster, and WILLIAM YOUNG, of Clippens, in the County
of Renfrew, North Butai, Oil Works Manager, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF
ILLUMINATING GAS, AND IN THE APPARATUS EMPLOYED THEREFOR,"
" to be as
follows, that is to say ·
This Invention which relates to improvements in the manufacture of

page_text: First. The more perfect and complete application for the manufacture
of illuminating gas of the liquid volatile hydrocarbons produced, and
ordinarily left in the tars when coal, shale, hydrocarbon oils, resin, or
other similar bituminous substances are destructively distilled for thic
production of illuminating gas
And, Second. The economical use of the fixed carbon contained in
the coke resulting from the destructive distillation of bituminous
substances contaming a large quantity of mineral matter, and also the
removal and use of graphite deposited in and on the surface of gas
retorts.
In the Specification of Letters Patent granted to Henry Aitken, of
Falkirk, in the County of Stuling, North Britam, dated 24th July 1874,
No 2587, there are described various means and apparatus for enhancing
the illuminating power of gases produced by the destructive distillation
of coal and other substances, by cuabling the crude gases as they are
formed to retain or become saturated with the volatile hydrocarbon
vapours ordinarly removed by the tars. Although that process suc-
cessfully accomplishes the objects aimed at and enables the gas to
become saturated with the vapours of the hydrocarbons produced
simultaneously with them, yet however perfectly the gases may bc
saturated with the vapours of the hydrocarbons present there are almost
invariably left combined with and which are removed by the tars a
quantity of hydrocarbons sufficiently volatile and suitable for combining
with poorer gases and adding to their illuminating power.
The first part of this Invention consists in a more perfect application
of the apparatus and means, or others similar in action to those described
in the aforesaid Specification, whereby those remaining hydrocarbons
left in the tars resulting from the destructive distillation of the
bituminous substance for the manufacture of illuminating gas are made
to combine with gases having little or no illuminating power, but
which by so doing are capable of becoming good illuminating gas.
Many of the bituminous coals and shales used for the production of
illuminating gases contain so large a quantity of mineral matter or ash
as to render the resulting cokes practically valueless and unsuitable for
use in the furnaces of gas retoris.
The second part of this Invention then consists in the utilization of
a portion of the carbon contained in such cokes by the decomposition of

page_text: steam, and the production of the non-luminous gases hydrogen and
carbonic oxide (to be afterwards used in the manner herein-after
described to combine with the hydrocarbons contained in crude tars);
also for the utilization of the carbon or graphite deposited in and on the
inner sides of gas retorts, and of the carbon deposited on the surface of
highly heated substances when used in the retorts to decompose
bituminous vapours for the production of gas; both of which are at
present a source of considerable annoyance and loss; the one by
gradually diminishing the carbonizing arca of the retort, and the other
by closing up the pores or spaces in the incandescent material through
which the bituminous vapours pass in order to be decomposed.
The general rationale and the simplest means of carrying this Inven-
tion into effect consists in subjecting the bituminous substance to
destructive distillation in the form of ictort usually employed for that
purpose, the resulting crude gases being treated in an analysing and
condensing arrangement similar to that set forth in the aforesaid
Specification of the said Henry Aitken, whereby the crude gases and
tars are subjected to a fractional separation or condensation, the former
passing away to purifiers perfectly saturated with as much of the hydro-
carbon vapours as they can permanently retain, and the latter containing
the surplus hydrocarbons falling back into trays or vessels set to receive
thicm So soon
as the bituminous substance has been completely
exhausted of its volatile matter or nearly so, steam or water is led into
the end of the retort furthest from the outlet or stand pipe, this water (as
is well known) will immediately upon coming into contact with the
residual carbon become decomposed and converted into hydrogen and
carbonic oxide Those gases are in tuin passed into the analysing and
condensing apparatus, and are there brought into contact with the
licated volatile hydrocarbons contained in the residual tars which were
more than sufficient to saturate the original crude gases The bydrogen
and carbonic oxide are thereby enabled to become saturated or combined
with the vapours of these hydrocarbons, and are converted into
illuminating gas, which is then passed on and combined with the
previously manufactured bituminous gases
The above arrangement may be advantageously adopted in small
works, but in large works where a considerable number of retorts are
employed, and where it would be almost impossible so to arrange the
charging and discharging of retorts as to have the bituminous and non-

page_text: luminous gases alternately succeeding each other, it is necessary to
employ other modified arrangements and means suited to the conditions
surrounding the different forms of apparatus and materials employed in
existing works, as herein-after set forth.
Although considerable advantages may be derived from simultaneously
subjecting the mixed bituminous and non-luminous gases to the action
of a single analysing and condensing apparatus, yet in order to obtain
the full benefit of this Invention it is advisable that the different gases
should be kept separate in order that the non-luminous gases may be
brought into contact with the tars after they have been separated from
the bituminous gases, as the non-luminous gases are thereby enabled
to more perfectly take up all the volatile hydrocarbons icmaining in
the tars.
In works where through retorts are employed, and which are provided
with an outlet or stand pipe at each end, the gases can be readily kept
separate by using the one stand pipe and hydraulic main exclusively
for the bituminous gases, and the other for the non-luminous hydrogen
and carbonic oxide, or where single retorts are used the separation may
be conveniently effected by fitting to the top of cach stand pipe a double
branch piece, and connecting each branch with a soparate hydraulic
main, and causing the gases to pass into either, as desired, by providing
cach branch pipe with a hydraulic or other valve hung upon a beam or
its equivalent in such a manner that the closing of the onc opens the
other, except when drawing and charging the retorts, when both would
require to be closed. On the other hand, where the carbon in the coke
resulting from the distillation of any bituminous substance is not
sufficient to decompose the quantity of water into the hydrogen and
carbonic oxide necessary to take up all the vapours of the surplus
hydiocarbons, or where it is desirable to preserve the coke resulting
from the distillation of the bituminous substance distilled for gas, then
any of the well-known methods for producing hydrogen and carbonic
oxide may be resorted to, or if it is not convenient or advisable to
employ hydrogen and carbonic oxide as the medium for taking up and
conveying the vapours of the surplus hydrocarbons contained in the
tais then such gases may be employed as those resulting from the
destructive distillation of such substances as peat, spent bark, and those
coals which give a gas having a low illuminating power, but by
whatever means the gases are produced in order to enable them to take

page_text: up and retain the whole of the volatile hydrocarbons resulting from the
bituminous substance they are sufficient to treatment in various forms
of the apparatus as now to be described.
By one method the bituminous and non-luminous gases as they are
produced may be combined or mixed in the retort in which the
bituminous substance is being distilled, and the whole gases passed into
an analysing and condensing arrangement similar to that described in
the Specification previously referred to
Second. The illuminating gases or those derived from the destructive
distillation of the bituminous substance are condensed in the ordinary
condensers employed for that purpose, and the tars resulting from such
treatment transferred to an analysing and condensing arrangement,
through which they fall and mect the poor or non-illuminating gases,
which are made to pass and take up all the volatile hydrocarbons from
said tars.
By a third method both kinds of gases are simultaneously and
separately treated in a combined analysing and condensing arrangement,
the bituminous gases being introduced a considerable way up the side,
and the non-luminous gases on the other hand being introduced into the
very bottom of the analyser Both gases are made to pass upwards
from where they are admitted, and therefore the bituminous gases are
treated or analysed in the upper half of the analyser, and the resulting
tars made to fall back to the lower half, where they come into contact
with the ascending current of non-luminous gases, which combine with
and carry up with them all the vapours of the hydrocarbon sufficiently
volatile to remain in diffusion Both gases are also blended or mixed
in the upper half of the analyser before they are finally condensed or
cooled down to a temperature approaching that of the surrounding
air.

page_text: and WILLIAM YOUNG, of Clippens, in the County of Renfrew, North
Britain, Oil Works Manager, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of August, in the year
of our Lord One thousand eight hundred and seventy-five, in the
39th year of Her reign, did for Herself, Her heirs and successors,
give and grant unto us, the said Henry Aitken and William Young, Her
special license that we, the said Henry Aitken and William Young,
our executors, administrators, and assigns, or such others as we, the
said Henry Aitken and William Young, our executors, administrators,
or 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, excrcise, and vend, within the
United Kingdom of Great Britain and Ircland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANUFACTURE
of Illuminating Gas, and in the APPARATUS EMPLOYED THEREFOR,” upon the
condition (amongst others) that we, the said Henry Aitken and William
Young, by an instrument in writing under our hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
samo to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters

page_text: And, Secondly. To effect the economical use of the fixed carbon con-
tained in the coke resulting from the destructive distillation of bituminous
substances, having combined or mixed with them a large quantity of
mineral matter, and also to remove and utilize the graphite deposited in
and on the surface of gas retorts.
The accomplishment of the aforesaid objects constitutes essentially the
practical working of what is well known to gas engineers as the "hydro-
carbon process." The difficulty hitherto experienced in the practical or
commercial working of the "hydrocarbon process" has principally been
the production of a gas having an uniform illuminating power, this
difficulty arising from the want of efficient means for regulating the
supply of hydrogen or other gas necessary to take up the hydrocarbons
produced from the bituminous substance as it undergoes distillation
With any of the forms or arrangements of apparatus hitherto employed
it has been essential that the water gas should be passed into the bitu-
minous retort whilst the bituminous substance is undergoing distillation,
or mingled with the warm crude bituminous gases as they are produced,
and in as near as possible the proportion necessary to combine at once
with the hydrocarbon vapours as they are produced from the bituminous
substance, for, in the event of the water gas being in too large a quantity,
the resulting mixed gases have been deteriorated in their illuminating
power by diluting the bituminous gascs too much. On the other hand,
in the event of the water gas being deficient in quantity, the hydro-
carbons have not all been taken up and diffused through the mixed
gases, and have therefore been condensed and removed by the tars. As
during the distillation of a charge of coal the hydrocarbons produced
suitable for being so taken up by water gas are constantly altering in
quantity, being most abundant at the early stages of the distillation, and
gradually diminishing until in the latter stages they are almost entirely
wanting, it is easily perceived that considerable difficulty occurs in
regulating the supply of water gas.
By this Invention those defects are obviated or in a great measure
modified, and the "hydrocarbon process" made a valuable one by
utilizing the means herein-after described.
In the Specification filed under Letters Patent granted to Henry
14

page_text: apparatus for enhancing the illuminating power of gases produced by
the destructive distillation of coal and other substances by enabling the
crude gases as they are formed to retain or become saturated with the
volatile hydrocarbon vapours ordinarily removed by the tar's. Although
that process successfully accomplishes the objects aimed at, and enables
the gas to become highly charged with the vapours of the hydrocarbons
produced simultaneously with them, yet however perfectly the gases
may be charged with the vapours of the hydrocarbons present there are
almost invariably left combined with (and which are removed by the
tars) a quantity of hydrocarbons sufficiently volatile and suitable for
diffusing amongst or combining with poorer gases, and adding to their
illuminating power
The first part of this Invention then consists in a more perfect appli-
cation of the apparatus and nicans, or others similar in action to those
described in the aforesaid Specification of the said Henry Aitkin, whereby
those remaining hydrocarbons left in the tars resulting from the destructivo
distillation of the bituminous substance for the manufacture of illumi-
nating gas are caused to combine with gases having little or no
illuminating power, but which by so doing are capable of becoming
good illuminating gas.
Many of the bituminous coals and shales used for the production of
illuminating gases contain so large a quantity of mineral matter or ash
as to render the resulting cokes practically valueless and unsuitable for
use in the furnaces of gas retorts.
The second part of this Invention then, as aforesaid, consists in the
utilization of a portion of the carbon contained in such cokes by the
decomposition of steam and the production of the non-luminous gases,
hydrogen, and carbonic oxide (to be afterward used in the manner berein-
after described to combine with the hydrocarbons contained in ciude
tars), also for the utilization of the carbon or graphite deposited in and
on the inner sides of gas retorts, and of that carbon which is deposited
on the surfaces of highly heated substances when such are used in
retorts for decomposing bituminous vapours for the production of gas,
both of which depositions of carbon are at present a source of con-
siderable annoyance and loss, the graphite by gradually diminishing the
carbonizing area of the retort, and the carbon deposited on the substances
being distilled by closing up the pores or spaces in the highly heated

page_text: decomposed.
The general rationale and the simplest means of carrying this Inven-
tion into effect consists in subjecting the bituminous substance to
destructive distillation in the form of retort usually employed in gas
works for that purpose, the resulting crude gases being treated in an
analysing and condensing apparatus similar or analogous to that set
forth in the aforesaid Specification of the said Henry Aitken, whereby
the crude gases and tars are subjected to a fractional separation or
condensation, the former passing away to purifiers charged with as
much of the hydrocarbon vapours as they can take up, and the latter
containing the surplus hydrocarbons falling back into trays or vessels
set to receive them So soon as the bituminous substance has been
completely exhausted of its volatile matter, or nearly so, steam or water
is led into the end of the retort furthest from the outlet or stand pipe.
This water or steam (as is well known) will immediately upon coming
into contact with the hot residual carbon. become decomposed and con-
verted into hydrogen and carbonic oxide. Those gases are in turn
passed into the analysing and condensing apparatus, and are there
brought into contact with the heated volatile hydrocarbons contained in
the residual tars which were more than sufficient to fully charge the
original crude gases The hydrogen and carbonic oxide are thereby
enabled to become highly charged or combined with the vapours of
these hydrocarbons, and are converted into illuminating gas which is
then passed on and combined with the previously manufactured bitu-
minous gases
The above arrangement may be advantageously adopted in small
works, but in large works where a considerable number of retorts aic
employed, and where it would be almost impossible so to arrange the
changing and discharging of retorts as to have the bituminous and non-
luminous gases alternately succeeding each other, it is necessary to
employ other modified arrangements and means suited to the conditions
surrounding the different forms of apparatus and materials employed in
existing works, as herein-after set forth.
In works where through retorts are employed and which are provided
with an outlet or stand pipe at each end, the gases can be readily kept
separate by using the one stand pipe and hydraulic main exclusively for

page_text: the bituminous gases, and the other for the non-luminous hydrogen and
carbonic oxide, or where single retorts are used the separation may be
conveniently effected by fitting to the top of each stand pipe a double
branch piece, and connecting cach branch with a separate hydraulic
main, and causing the gases to pass into cither, as desired, by providing
each branch pipe with a hydraulic or other valve hung upon' a beam or
its equivalent in such a manner that the closing of the one opens the
other, except when drawing and charging the retorts, when both would
require to be closed. On the other hand where the carbon in the coke
1esulting from the distillation of any bituminous substance is not
sufficient to decompose the quantity of water into the hydrogen and
carbonic oxide necessary to take up all the vapours of the surplus
bydrocarbons; or where it is desirable to preserve the coke resulting
from the distillation of the bituminous substance distilled for gas, then
any of the well known methods for producing hydrogen and carbonic
oxide may be resorted to, or if it is not convenient or advisable to
employ hydrogen and carbonic oxide as the medium for taking up and
conveying the vapours of the surplus hydrocarbons contained in the tars,
then such gases may be employed as those resulting from the destructive
distillation of such substances as peat, spent bark, sawdust, and those
coals which give a gas having a low illuminating power, but by what-
ever means the gases are produced in order to enable them to take up
and retain the whole of the volatile hydrocarbons resulting from the
bituminous substance they are subjected to ticatment in various
arrangements of apparatus herem-after described.
By one method the bituminous and non-luminous gases as they are
produced may be combined or mixed in the retort in which the bitu-
minous substance is being distilled, and the whole of the gases passed
into an analysing and condensing arrangement similar to that described
in the Specification previously referred to.
By a second method the illuminating gases or those derived from the
destructive distillation of the bituminous substance are condensed in the
ordinary condensers employed for that purpose, and the tars resulting
from such treatment transferred to an analysing and condensing arrange-
ment, through which they fall and meet the poor or non-illuminating
gases, which are made to pass and take up all the volatile hydrocarbons
from tlic tars.

page_text: By a third method both kinds of gases are simultaneously and
separately treated in a combined analysing and condensing arrangement,
the bituminous gases being introduced a considerable way up the side,
and the non-luminous gases on the other hand being introduced into tho
very bottom of the analyser. Both gases are caused to pass upwards
from where they are admitted, and therefore the bituminous gases are
treated or analysed in the upper half of the analyser, and the resulting
tars made to fall back into the lower half, where they come into contact
with the ascending current of non-luminous gases, which combine with
and carry up with them all the vapours of the hydrocarbon sufficiently
volatile to remain in diffusion Both gases are also blended or mixed
in the upper half of the analyser before they are finally condensed
or cooled down to a temperature approaching that of the surrounding
air.
By a fourth method, which is used in cases where it is desired to
exhaust the tars to such an extent as to reduce them to a condition of a
hard pitch, it is essential to raise the temperature of the analyser to a
higher extent, which may be effected by the ducet application of a fire
or by superheated steam, and for this purpose it is preferied to employ
the horizontal analyser herein-after described
And in order that our said Invention may be propeily 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.-
--
Figure 1, Sheet 1, is a section partly in elevation of an arrangement
of apparatus for the manufacture of water gas (hydrogen and carbonic
oxide) or other gas having a low illuminating power in one set of retorts,
which is afterwards passed through a second set of retorts, in which
bituminous coal or other similar substance is being distilled, and the
combined gases subjected to the action of the analyser or fractional
condensing arrangement.
The retorts 1 and 2 for the production of the water gas or other poor
gas are set in a vertical position, and heated by a furnace placed at one
side, but which is not shown in the Diawing. The carbon necessary for
the decomposition of the water is introduced by the hopper and valve
arrangement 3 by filling the hopper 4, and then opening the valve 5

page_text: by depressing the lever G, when the coke or other carbonaceous matter
falls into the retort. The retort 1 is kept at a very lugh temperature,
and steam is admitted thereinto in a regulated stream by the valve 7
communicating with the inain steam pipe 8 led from the steam boiler 9.
On this main steam pipe S there is placed a regulating valve 10 actuated
by the lever 11 connected to, a small governing gas holder 12, which
being raised or lowered by the pressure of the gas passed by the pipe 18
regulates the quantity of steam to be admitted for the production of the
necessary quantity of hydrogen.
The horizontal portion of the retort 2 may be either filled with coke
or fire-brick, the purpose of introducing which is more especially to
prepare the steam by heating it for after decomposition rather than to
decompose it. The water trough 14 at the bottom, and into which the
retort 1 dips, scals it, and at the same time allows the ashes resulting
from the carbonaceous matter introduced into the retort to be removed.
The steam, after being heated in the horizontal portion of the retort 2,
passes up through the coke or carbonaceous matter into the body of the
retort 1, when it is decomposed into water gas, and is then drawn off by
the outlet pipe 15, and passed to the hydraulic main 10 and' condensers 17,
wherein any water which may have escaped decomposition is condensed
and removed by the pipe 18 Should the carbon employed for decom-
posing the water contain sulphur the gas may be also purified to remove
sulphur compounds present, and after being so purified it is then passed
through the meter 19 to be measured, and thence to the main pipe 20
for supplying the bituminous gas retorts 27.
The bituminous gas retorts 27 may be of the ordinary horizontal
description The water gas or other poor gas is admitted to the bitu-
minous retorts by the pipes 21 and 26 leading from the main gas pipe 20
through the screw valve 22 To admit the water gas automatically the
apparatus shown on an enlarged scale at Figure 2 is employed, this
being so constructed that the pressure of the gas on the retort being
charged lifts the small gas holder 23, which actuates the valve 24
covering the pipe 21, and thereby allows the water gas which is kept or
made under a considerably greater pressure to pass by the pipe 20 to
the bituminous retort On the pressure being removed from the retort
the small holder 23 at once falls and shuts off the supply of water
ras.

page_text: The mixed bituminous and water gases pass off by the standpipe 28
to the hydraulic main 29, and thence by the pipe 30 to the analyser or
fractional condenser A, which may partake of a variety of forms, as
illustrated and described in the aforesaid Specification of the said Henry
Aitken. The analyser or fractional condenser A, shown at Figure 1, is
considered by us to be amongst the best forms of this apparatus, and it
is very similar to the ordinary "Coffey" still analyser. This analysing
arrangement consists, as will be seen on referring to the Drawings, of
a vertical tower or chamber having tray diaphragms 31 placed at
intervals and so arranged that the gases in their passage between these
trays are caused to travel in a tortuous course alternately from the sides
to the centre, the apertures through which the gas has to pass being
alternately at the sides and the centre of the trays; hanging from the
edges of the central part of the trays, and dipping into the tars in the
tays underneath, aro tubes of wire gauze 32, perforated metal, or an
equivalent porous arrangement may be adopted. Two of the lower
trays 31' and bottom 31 of the tower are shown cased or doubled (but
more of the trays may also be so constructed), and into this space
steam is admitted by the pipe 33 connected to the steam boiler 9,
and the condensed water is drawn off by the pipe 34 and valve 35
The combined bituminous gases and water gases or other non-
luminous gases with the suspended crudo tars on entering the fractional
analyser or condenser by the pipe 30, pass under the lowest tray 31" and
over the surface of the heated tars in the bottom of the analyser, and
so that they are bathed in a large volume of the comparatively volatile
vapours of the hydrocarbons given off from the heated tars, which
causes the heavy tarry particles suspended in the crude gases to be
partially deposited The gases then travel over the first tray 31* and
through the wie gauze tube 32 hanging from the edges of the aperture
in the second tray 31, which effects a further separation of the
mechanically suspended tars, and at the same time the gases receive lighter
hydiocarbon vapours from the tars flowing over the wire gauze 32 from
the second tray Tbis process is repeated by the passing of the gases
through the second wire gauze and over the surface of the heated tars
contained in the third tray, and so on, on ascending from tray to tray.
The tars contained in the succeeding trays are successively heated to a
less degree. The ascending gases becoming gradually cooled, deposit
heavy hydrocarbon vapours and receive lighter ones, until by the time

page_text: they reach the outlet pipe 36 leading to the scrubbers, they have parted
with all, or nearly all, their tarry particles and only contain those
vapours of hydrocarbons diffused through them, most of which remain
permanently suspended, a small portion only being removed by the
scrubbers, which is again returned by the pipe 37 to be used in car-
buretting a fresh quantity of gas At the same time that the gases
are being deprived of tarry particles and receiving volatile vapours, the
deposited tars and condensed heavy hydrocarbon vapours descend from
tray to tray, and, as already described, re-part with any absorbed
vapours sufficiently volatile to the ascending current of gas, until by the
time the tars reach the bottom they are almost or practically denuded
of volatilo hydrocarbons and 'pass away by the pipo 38 to the tar
tanks.
Figure 3, Slicet 1, is a section partly in clevation showing how the
process may be conducted by the alternate production of bituminous
gas and water gas in the same ordinary horizontal retort. When the
illuminating or bituminous gas is made from coal or similar solid
material, the retort 27, Figure 3, is first charged with the substance
and the destructive distillation completed, or nearly so, the gas passing
away by the stand pipe 28, hydraulic main 20, and pipe 30, to the
analyser A, heated by the steam pipe 33, connected to the steam boiler 9,
and there subjected to treatment as herein-before described, only in thus
case the bituminous gas leaves behind it in the condensed tars, hydro-
carbons which can be taken up by a poor gas The poor or water gas
is made by opening the valve 7 on the pipe S, connected to the steam
boiler 9, heated by partially spent heat in the main fluc 39. The steam
entering the retort 27 comes into contact with the carbon (graphite)
deposited on the surface of the retort and that contained in the residual
cokc, and is thereby decomposed into hydrogen and carbonic oxide,
which in turn is passed by the outlet pipe 28, hydraulic main 29, and
pipe 30, to the analyser A, and therein coming into contact with the
heated tars contained in the trays takes up the volatile hydrocarbons
left in the tars by the bituminous gases. The deposited carbon (graphite)
is thus removed from the retort and utilized, and the retort itself is thus
kept clean and effective.
When the bituminous substance employed for the production of thic
illuminating gas is a liquid, such as mineral oil, or a solid which may
be melted and kept liquid at conveniently low temperatures, such as

page_text: resin, the process is slightly modified, the retort being charged with
coke, broken brick, scrap iron, or other substance presenting a large
surface, and the mineral oil or other bituminous liquid is led into the
retort 27 by opening the valve 40 on the pipe 41, connected to the
tank 42 The oil, as is well known, on entering the retort is immc-
diately volatilized, and in its passage through or among the highly
heated solid matter in the retort is decomposed and converted into crude
illuminating gas, solid carbon being at the same time deposited on the
surface of the hot solid substance and on the surface of the retort. The
oil gas passes away to the analyser, where the condensible portion is
removed. At intervals the admission of oil is stopped and steam
admitted as before from the boiler 9. This steam is decomposed by the
carbon deposited from the oil, and the resulting gases passed through
the analyser to take up the surplus hydrocarbons condensed from the
rich oil gas
Both gases are afterwards blended or mingled in the gas
holder, and instead of introducing steam ready formed into the retort,
water may be run in directly and converted into steam inside the retort
but it is preferable to pass in the steam ready formed.
Figure 4, Sheet 1, is a section partly in clevation of an arrangement
where the process is conducted by the simultaneous production of
bituminous and water gas in one retort, but which may also be modified
so as to produce these gases intermittently This arrangement is more
particularly designed for the distillation of coal, shale, and similar
substances containing a large percentage of ash but which give a gas of
considerable illuminating power. The retort is similar to that already
referred to in Figure 1 for the production of water gas, having a vertical
limb or portion 1 and a horizontal limb or portion 2 The latter is quito
filled with coke, and the former to the extent of two-thirds or there-
abouts The bituminous shale, coal, or other substance is charged by
the hopper 3, and valve 5, into the remaining or upper third part of the
vertical portion of the retort, and is there distilled into crude illumi-
nating gas. At the same time steam is admitted into the horizontal
limb or portion of the retort 2 by opening the valve 7 ou the pipe 8,
leading from the steam boiler 9. This steam in its passage through the
highly heated coke is decomposed, producing water gas, which combines
and mingles with the rich bituminous gases as they are produced from
the shale, coal, or analogous substance contained in the upper third part
of the retort. The combined gases pass by the outlet pipe 15 to the

page_text: hydraulic main 16, and thence by the pipe 30 to the analyser and are
thercin subjected to the treatment herein-before described. As soon as
the first charge of shale or other bituminous substance is nearly worked
off, some of the ash is drawn from the bottom of the retort in the water
trough 14, and a fresh charge of shalo introduced. The coke of the
exhausted shale or other bituminous substance now supplies the carbon
for the decomposition of the water into hydrogen and carbonic oxide,
and thus the coke of shales and other bituminous substances which is
otherwise almost valueless is economically utilized
This last arrangement of apparatus may be also advantageously
employed for the manufacture of illuminating gas from resin, mineral
oil, and similar liquid hydrocarbons by leading into the retort the oil
in a stream above, and passing water gas up and commingling it with
the oil gases as they are produced, using the deposited carbon from the
oils for the production, or to assist in the production of this water gas,
or by making the process intermittent by shutting off the steam by the
valve 7 from the horizontal portion of the retort, and admitting oil by
opening the valve 40 on the pipe 41 connected with the oil tank 42.
The oil on entering the horizontal portion of the retort is volatilized
and decomposed in passing up through the heated solid matter charged
into the vertical limb or portion 1 for the purpose So soon as the
interstices between the highly heated solid substances become so far
closed as to impede the flow and production of the oil gas, the oil is
shut off and the steam again admitted, which is decomposed and removes
the carbon deposited by the decomposition of the oil. In both cases
the gases are subjected to treatment in the analysing arrangement A
in the manner described. In practical working this process is repeated,
alternately admitting oil and steam.
On Sheet 2 of the appended Drawings, Figure 1 is a section with part
in elevation showing an arrangement for the production in separato
retorts of the bituminous and non-luminous gases, and for the simul-
taneous and separate treatment of both gases in a combined analysing
arrangement. The water gas and bituminous gas retorts and the
analyser are similar in construction to those hercin-before described in
reference to Figure 1, Sheet 1, and similar numbers refer to similar
parts of the apparatus. The gases are also produced in a similar
manner, but instead of combining the different gases in the bituminous
retorts they are kept separate and carried into the analyser in two

page_text: separate currents, the crude bituminous gases and tars being introduced
as shown by the pipe 30 between the fourth and fifth tray from the
bottom of the analyser A, at the same time the water gas or other poor
gas is introduced by the pipe 20 at or near the bottom of the analyser ;
both gases pass upwards from where they are admitted. The bituminous
gases as they enter from the hydraulic main 29 by the pipe 30 aro warm,
and are further raised in temperature by the heat of the water gas
rising up from below
The mingled gases are thus subjected to the
analysing action herein-before described in their tortuous passage through
the higher trays and wire gauze tubes in the analyser At the same
time the tars and condensible heavy vapours deposited from the gas in
the upper portion of the analyser fall back from tray to tray until they
drop through into the trays 31 in the lower part of the analyser,
wherein they are heated by the steam as before described. At this place
the heated tars are acted upon by the incoming current of water gases
or other poor gases, and any traces of hydrocarbons which may remain
in the tars and which are sufficiently volatile are taken up by the gas,
and the tars pass away denuded as far as practicable by the pipo 36
leading to the tar tank.
Figure 2, Sheet 2, shows an arrangement of double ended or through
ictoris, by which the process of making illuminating gas according to
this Invention may be conducted in varied ways By one more the
retorts 27 and 27" are charged to the extent of one half with the
bituminous substance, the other half being filled with coke. The
hydraulic valve 29' in the stand pipe 28 leading from the end of the
retort filled with coke is lifted and closed, and the hydraulic valve 16'
on the pipe leading from the opposite end of the retort is lowered and
opened At the same time the lowering of the valve 16" actuates the
10d 43 connected to the valve 44, which admits steam from the steam
boiler 9 by the pipe 45 and stand pipe 28 into the end of the retort 27*
filled with coke The steam in passing over the coke is decomposed
into hydrogen and carbonic oxide This gas then passes over and through
thic bituminous substance distilling in the other end of the retort 27,
and the mixed bituminous and water gas pass away by the stand pipe 28ª
to the hydraulic main 16, and thence by the pipe 20 to the analyser to
be there subjected to treatment in the manner herein-before described.
So soon as the first charge of bituminous substance is exhausted, the
valve 16 is closed and the coke removed from the end previously
B

page_text: employed to make the water gas, and replaced by a charge of the
bituminous substance The valve 29' being now lowered opens the
valve 46, and admits steam from the boiler 9 to the opposite end of
the rotoit 27, which contains the coke from the previous charge of
bituminous substance, and by which the steam is at once decomposed
into water gas
This water gas in turn passes over the fresh charge of
bituminous substance in the end of the retort 27', and by the stand
pipe 28 to the hydraulic main 29, and thence by the pipe 20 to the
analyser This process is repeated, alternately charging the reverse
ends of the retort with the bituminous substance, and using the coke in
the opposite end derived from the provious charge of bituminous
substance to decompose the water for supplying the water gas to take
up the surplus hydrocarbons that would be left in the analyser by the
bituminous gases
Instead of making the water gas in one end of the retort, any
substance, such as speut bark, sawdust, peal, or others giving a large
proportion of poor gas, may be employed to produce the gas to take up
and utilize the volatile hydrocarbons, the bituminous substance being
charged at the same time, and the poor gas from the other substance
caused to pass over and out by the same stand pipe together with the
bituminous gases.
Another mode of working the process is similar to that alıcady
described with reference to Figuic 4, Sheet 1, and it is conducted as
follows The rod 47 connecting the lever 48 of the hydraulic valve 29ª
on the stand pipe 28 and steam valvo 46 on the pipe 49 leading from
the steam boiler 9 is disconnected. The entire length of the retort is
now charged with the bituminous substance, and the crude bituminous
gases are passed away by the stand pipe 28 to the hydraulic main 29,
and thence to the analyser by the pipe 30, shown in dotted lines So
soon as the bituminous substance is exhausted the hydraulic valve 29*
is raised and closed, and the hydraulic valve 16* is lowered and opened.
At the same time the steam valve 44 is also opened by means of the
connecting rod 43 attached to the lever 50 of the hydraulic valve 10ª.
Steam is thereby admitted into the retort by the pipe 45 and stand
pipe 28", which coming into contact with the highly heated coke is
decomposed into water gas, and drawn off by the stand pipe 28* into the
hydraulic main 10*, and thence passed by the pipe 20 into the bottom of
the analyser. The retorts are so worked that about one-half of them arc

page_text: producing water gas during the time the other half are producing
bituminous gas, and the two gases are collected in the manner described
in the separato hydraulic mains, being afterwards separately and simul-
taneously treated as licrein-before described in reference to Figure 4,
|Sheet 1, into the combined analysing apparatus A.
By a third mode of making gas according to this Invention with the
apparatus shown at Figure 2, Sheet 2, the bituminous gas may be passed
into ordinary condensers, as shown by the dotted pipe 30° and at 51,
Figure 2 The condensed tars are run off by the scaled pipe 52 to the
tar well 53, and the tar is pumped from thence by the pipes 54 and
pump 55 to the top of the analysing apparatus A At the samo timo
the water gas is passed by the pipe 20 through the analyser, and takes
up the surplus hydrocarbons contained in the pumped tars from the
bituminous gases.
The resulting gases may be either kept separate and used separately,
or, as shown in the Drawing, combined by the connecting pipe 56 and
passed on to scrubbers and purifiers together by the pipe 36.
The Diawing on Sheet 3 exhibits an arrangement of gas apparatus,
which may be in many cases advantageously employed to carry out the
process, more especially where it is desired to reduce the tars to a scini or
wholly pitched or solid condition, and when the gases are not required to
have a very high illuminating power.
The retort shown is specially adapted for the production of gases
suitable to be treated by this process from shales, coals, and similar sub-
stances, giving by the ordinary process of gas making a gas of very high
illuminating power
The retort consists of three connected limbs or
parts 1, 2, and 3 The bottom limb 1 is kept charged with the coke
from shale or other substance distilled, the limb 2 is charged with
similar coke or anthracite coal, bricks, or scrap iron, or any material
capable of resisting a high heat and presenting a largo surface; the
higher limb 3 is charged by the hopper and valve 4 with bituminous
substance, the crude illuminating gases from which pass downwards into
the limb 2 At the same time steam is admitted into the bottom limb 1
by opening the valve 5 on the pipe 6 connected to the steam boiler 7.
This steam in passing upwards to the limb 2 undergoes decomposition by
coming into contact with the carbon contained in the shale or other
coke The two gases (bituminous and water gas) mingle and blend on
'

page_text: entering the limb 2, and the undecomposed liquid hydrocarbons con-
tained in the bituminous gas undergo a further decomposition in the
presence of the water gas by coming into contact with the surface of
the heated solid material through which they have to pass. As soon as
the first charge is exhausted spent ash is drawn from the bottom of the
retort resting in the water trough 8. This empties or partially emptics
the upper limb of the retort, which is again filled with a fresh charge of
bituminous shale or other gas producing material, this process is con-
tinuously repeated. The combined gases pass off by the stand pipe 9 to
the hydraulic main 10, and thence by the pipe 11 to the analysing
apparatus 12, which consists of a horizontal still or chamber divided by
a series of partitions 13, in such a manner as to cause the gases and tars
to pass in a tortuous manner from one end of the chamber to the other,
the tars and gases passing in opposito directions, as shown by the
arrow's Underneath this chamber or analyser is placed a furnace 14 by
which the tars and gases may be heated to the required temperature,
according to the quality of pitch desired, the harder the pitch required
the higher is the temperature necessary. The gases enter this analysing
apparatus by the pipe 11, and undeigo very similar ticatment to that
described in reference to the working of the analysing apparatus shown
on the two preceding Sheets of Drawings. The gases as they pass from
division to division of the apparatus 12, deposit heavy vapours and tar
particles, and take up lighter hydrocarbon vapours until on leaving the
analyser by the pipe 14, they are almost freed of tars proper and contain
only vapours of the more volatile hydrocarbons derived from the tar.
To enable the gases to hold those comparatively heavy hydrocarbon
vapours they pass from the analyser more or less heated, and thence
through the coolers or condensers 15, or where the temperature is very
lugh a second vertical analysing apparatus may be employed to reduce
the temperature of the gases The condensed matters, ammoniacal
liquor, and liquid hydrocarbons arc run off, the former into the liquor
tank to supply the scrubbers by the stop cock 10, the latter can either
be returned by the cock and funnel pipe 17 to the horizontal analyser,
or disposed of as heavy tar naptha direct. The analysed tars or pitch
arc from time to time run off from the analyser 12 by the cock 18 into
a sand bed or other form of mould to be cooled. The tar is led from the
hydraulic main 10 into the chamber 12 by the pipe 19
In working this Invention by any of the herein-before described or
analogous arrangements of apparatus the quantity of hydrogen and

page_text: carbonic oxide, or other gases having a low illuminating power, necessary
to take up the hydrocarbons from the crude gases produced from any
given bituminous substance, and to produce a gas of the desired illumi-
nating power, must first be ascertamed by trial through distilling a
given weight of the bituminous substance and adding the water or other
gas until the desired illuminating power is attained.
Although in carrying out thus Invention it is not essential that the
water gases and bituminous gases be made at the same time, because the
action of the analyser upon the gases is such that considerable variations
may be made between the proportion of the bituminous and non-
luminous gases at the instant of their production, for should the
quantity of hydrogen or other non-luminous gas be insufficient to take
up the whole of the hydrocarbons produced, together with the bitu-
minous gas at the time, the surplus falls back into the trays of the
analyser, and on the other hand when the hydrogen or other non-
luminous gas is more than sufficient to take up the hydrocarbons fiom
the bituminous gases simultaneously produced then the previously con-
densed surplus hydrocarbon vapours contained in the trays serve to
supply thus deficiency The variations in the proportions of the gases
are in this manner practically balanced by the action of the analyser.
Yet where it can conveniently be done it is better that the water gas
should be passed into the bottom of the combined analyser in as iegular
a proportion as possible to the bituminous gases, so as to meet the
stream of crude tais contained in the surplus hydrocarbons as they drop
from the portion of the analyser in which the bituminous gases are
analysed and condensed, or where it is desuable to analyse the mixed
gases the water gas should be passed into the retort containing the
bituminous matter and there mingled with the crude bituminous gases
as they are climinated, as it appears the poor gases serve to shield from
over decomposition the hydrocarbons present in the clude bituminous
gases suitable for carburetting the poor gases Therefore in adding the
poor or water gases ascertained to be necessary to take up the hydro-
carbons from the bituminous substance and form the quality of gas
desired, the valves for admitting the water gas or the steam for its pro-
duction or other poor gas should be regulated to pass as near as possible
the average necessary quantity during the distillation of the weighed
bituminous substance A very short time will suffice to do this,
checking the quantity added by the meter, measuring the water, or other

page_text: poor gas alone, or by taking the gross quantity of mixed gases passed
through the ordinary station meter.
If desired the improvements in the manufacture of gas constituting
this Invention may be worked with a lower temperature of the analyser
by reducing the pressure of the gas or vapours therein to any desired
point below that of the atmosphere. This may be effected by the use of
an exhauster, steam jets, or the mechanical equivalent thereof placed
between the analyser and the scrubbers, regulating valves being placed
between the analyser and the retorts to prevent too much reduction of
thic pressure in the retorts Or a considerable portion of the force or
energy required to relieve the gases of the atmospheric pressure may be
utilized by passing the hot vapours and gases as they leave the hydraulic
main through a supplementary cylinder or cylinders actuating a piston
or pistons attached to the driving gear of the exhauster, the said gases
being worked more or less expansively according to the pressure desired
in the retorts. Under this method of working the attenuated hydrogen
or other gas of low illuminating power that may be used is rendered
capable of absorbing a large volume of the hydrocarbons
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 carried into practical effect, under various
modifications, we wish it to be understood that we do not confine or
restrict ourselves to the precise details or arrangements we have had
occasion to describe and delineate as many variations may be made
therefrom without departing from the main or essential features of our
said Invention, neither on the other hand do we claim as new or as our
Invention the decomposition of water into carbonic oxide and hydrogen
gases by highly heated carbon contained in gas retorts, nor do we claim
the combining the carbonic oxide and hydrogen so obtained with the
crude gases as they are produced from bituminous substances under-
going distillation either in the bituminous retort or out of it whilst
nor do we claim the carburetting of hydrogen and carbonic oxide
obtained from the decomposition of water by heated carbon or other gas
having a low illuminating power with the diffused vapours of hydro-
carbons in an isolated form, as we are aware that this has been previously
done to some extent for the like purpose to this Invention, as we have
already stated by means of what is known as the "hydrocarbon process,'
and by other means,
neither do we claim all the details of mechanical
walm,
"

page_text: 1
construction separately which we have had occasion to describe and
refer to (as many of these aro already in use) except in combination with
and as forming parts of the essential features and for the objects or
purposes of our said 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, -
First. The general combination or arrangement of apparatus and the
modes of using or applying the same for the treatment or distillation of
shalc, coal, mineral oil, resin, and other similar bituminous substances,
for the production of illuminating gas in conjunction with the pro-
duction or manufacture of hydrogen, and carbonic oxide by the
decomposition of water by heated carbon, and for the production of
other gases having a low illuminating power from spont bark, sawdust,
peat, and similar substances, and for the carburetting of the said water
gases or other poor gases by diffusing the vapours of hydrocarbons
produced with the illuminating gases from said bituminous substances,
and thereby making good illuminating gas therefrom, substantially in
the new or improved manner herein described and shown on the
accompanying Drawings or any mere modification thereof.
Second The application for the manufacture of illuminating gas of
thic volatile hydrocarbons produced, and ordinarily left in the tars, wlien
coal, shale, hydrocarbon oils, resin, and other similar bituminous
substances are destructively distilled for the production of illuminating
gas, by diffusing or suspending them in hydrogen, carbonic oxide, or
other gas or gases having a low illuminating power, through bringing
the said gases into contact with the tars (condensed from crude
bituminous gases) whilst in a heated state and spread over large surfaces,
or by mingling the hydrogen, carbonic oxide, or other poor gas with the
bituminous gases, either in the bituminous retort as they are produced,
or afterwards, and subjecting the mingled gases to fractional con-
densation or cooling, the condensed tars being kept in a heated state,
substantially in the new or improved manner herein described and
shown on the accompanying Drawings or any mere modification
thereof.
Third. The use or application of the fixed carbon contained in the
cokes resulting from the destructive distillation of bituminous sub-

page_text: matter or ash, and which are in consequence unsuited for fuel, and also
the use of the graphite or carbon deposited from bituminous substances
in and on the surface of the retort, and its contents for the decomposition
of water, and the production therefrom of hydrogen and carbonic oxide,
and converting the same into good illuminating gas by diffusing through
them the vapours of hydrocarbons derived from the destructive dis-
tillation of bituminous substances for illuminating gas, substantially in
the manner herein described and shown on the accompanying Drawings
or any mere modification thereof.
In witness whereof, we, the said Henry Aitken and William Young,
have hereunto set our hands and seals, this Twenty-fifth day of
January, One thousand eight hundred and seventy-six.
HENRY AITKEN.
(L.S.).
WILLIAM YOUNG.
(LS)