An Improved Process for the Manufacture of Illuminating Gas, and Apparatus therefor.
Year: 1890

page_text: Date of Application. 9th May, 1890
Complete Specification Left, 9th Mar., 1891-Accepted, 25th Apr., 1891
PROVISIONAL SPECIFICATION,
An Improved Process for the Manufacture of Illuminating Gas, and
Apparatus therefor.
ROBERT CATHCART LINDSAY, of 4, Oakhill Park, Hampstead, in the County
of Middlesex, M.A. Edin., do hereby declare the nature of this invention to be
as follows
In this process any kind of gas coal or cannel coal or other gas making material
may be used the coal or material being first carbonised in a retort. I prefer using
an inclined retort which can be charged and discharged with a minimum of labor.
The gas in the first instance is led away through an ordinary hydraulic main to a
condenser and washer where the tar and aqueous vapors are completely removed
and thence into an exhauster for further manipulation. Before withdrawing the
hot coke from the gas making retort steam is admitted to the same which is
decomposed in the first instance while the retort is very hot forming carbonic oxide
and hydrogen while later as the retort cools carbonic acid and hydrogen are formed.
This keeps the retorts free from deposited carbon at the same time increasing the
quantity of sulphur as well as ammonia in the gas. The increase of sulphur
would be very objectionable in ordinary gas making but is no objection in this pro-
cess as the total sulphur less what is contained in the gas used in firing the furnace
has to be removed from the gas before storing in the holder.
The coke resulting from this carbonisation is withdrawn from the retort hot
and placed in a second series of retorts where it is brought in contact with super-
heated steam. These second series of retorts are in batteries of two in the first of
which the steam is decomposed forming principally carbonic acid and hydrogen.
This imperfect water gas is further superheated before being passed through the
second water gas retort where the carbonic acid is converted into carbonic oxide.
This gas is subject to further manipulation. The retorts are placed four in a bench
for carbonising with four water gas retorts worked in pairs. The water gas retorts
have each two smaller fireclay pipes for the purpose of superheating first the steam
used in the first retort, second the imperfect water gas produced therein previous to
its passage into the second retort where it is converted into a perfect water-gas.
The reason I make water-gas in two stages is because the superheated steam is
decomposed at a much lower temperature than carbonic acid the carbonic acid being
subsequently superheated to facilitate its conversion into carbonic oxide.
For the purposes of this process hydrogen is required and is produced in special
upright retorts one in each end of the furnace which are fitted with iron trays filled
with spongy iron for making hydrogen while the gas produced as ultimately
carburetted to any desired degree of luminosity in three or more retorts or chambers
which are placed horizontally in the furnace.
All these retorts superheating pipes carburetting chambers and hydrogen pro-
ducing retorts are arranged in an oblong furnace of suitable dimensions.
One end of the inclined retorts and superheater pipe comes through the side of
the roof of the furnace the lower ends of the retorts come out through the front of
the furnace while the lower end of the superheater pipes communicate with the
lower end of the water gas retorts. Both ends of the retorts are provided with
suitable doors for charging and discharging.
Suitable arrangements are provided to allow the furnaces and retorts to expand
and contract without interfering the one with the other.
This furnace is by preference a gas fired furnace fitted with regenerators and
reversing valve for air only the gas being a waste gas hot from the hydrogen pro-
ducers. The superheating pipes are fitted with fireclay or porcelain battling plates

page_text: to increase its efficiency as a superheater. The furnace has also 3 or more
carburetting retorts which are also fitted with baflling plates to increase their
efficiency.
Within each end of the furnace is an upright fireclay retort fitted with iron trays
to contain spongy iron which is used to produce hydrogen by decomposition with
superheated steam. By this means I keep down the percentage of carbonic oxide
in the gas.
The iron within the retort being alternately oxidised by steam producing hydrogen
and then reduced to a metallic state by water gas. The partially exhausted water
gas being then used to maintain the heat in the furnace burning with the hot air
from the regenerator. The gas produced in the first carbonisation of the coal or
other material is delivered under pressure by an exhauster back to the retort bench
where it is divided into six or more parts and used in six or more jets one in each end
of the carburetters to draw the water-gas from the water-gas retorts. The water-gas
is carbonic oxide and hydrogen mixed with the hydrogen produced by decomposition
of superheated steam with the spongy iron and is forced through pipes in the centre
of the carburetter from each end to near the middle of the same. It then finds its
way to the outside ends of the carburetter coming in contact with the battling
plates with which it is fitted.
In carburetting I prefer doing it in three or more stages.
The total water gas and hydrogen with 3rd more or less of the ordinary gas produced
in the first carbonization of the coal or other material will be carburetted up to a
certain point in the first carburetter a sufficient quantity of hydrocarbon oil or tar
being added for that purpose.
A second 3rd more or less of the ordinary gas acting as a jet under a slight pressure
from the exhauster forces the gas through the second carburetter additional hydro-
carbon oil or tar being here added. The last portion of the gas acting as a jet
forces the gas again through the third carburetter.
By dividing the carburetting into 3 or more parts and adding the carburetting
material in 3 or more stages gas of any desired luminosity can be made with the
smallest amount of carburetting material.
The gus after passing through the last carburetter will be led away to coolers
scrubbers and purifiers and thence to the holders in the ordinary way.
It may be advantageous whenever the carburetting material is free from sulphur
to thoroughly purify both the gases before mixing and carburetting the same.
Dated this 9th day of May 1890.
R. CATIICART LINDSAY.
COMPLETE SPECIFICATION.
An Improved Process for the Manufacture of Illuminating Gas, and
Apparatus therefor.
I, ROBERT CATHCART LINDSAY, M.A., of 4, Oakhill Park, Hampstead, in the
County of Middlesex, do hereby declare the nature of this invention, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement. :—
My invention relates to an improved process for the manufacture of illuminating
gas and to apparatus therefor.
In carrying out the process any kind of gas coal or cannel coal or other gas
making material may be used the coal or material being first carbonised in a retort.
I prefer using an inclined retort which can be charged and discharged with a
minimun of labour. The gas in the first instance is led away through an ordinary
hydraulic main to a condenser and washer where the tar and aqueous vapors are
completely removed and thence into an exhauster for further manipulation. Before
withdrawing the hot coke from the gas making retort steam is admitted to the same
which is decomposed in the first instance while the retort is very hot forming car-

page_text: bonic oxide and hydrogen while later as the retort cools carbonic acid and hydrogen
are formed. The object of introducing this steam is to prevent the coke from
bursting into flame when it is removed from the retort before being divided among
the water gas retorts as hereafter described it being a preferable course to damping
the coke with water. This steam further keeps the retorts free from deposited
carbon but at the same time increases the quantity of sulphur as well as ammonia
in the gas. The increase of sulphur would be very objectionable in ordinary gas
making but it is no objection in this process as the total sulphur (less what is cou-
tained in the gas used in firing the furnace) has to be removed from the gas before
storing in the holder.
The coke resulting from this carbonisation is withdrawn from the retort hot and
placed in a second series of retorts where it is brought in contact with superheated
steain. Those second series of retorts are in batteries of two, in the first of which
the steam is decomposed forming principally carbonic acid and hydrogen. This
imperfect water gas is then superheated before being passed through the second
water gas retort where the carbonic acid is converted into carbonic oxide. This
gas is subsequently subject to further manipulation as will be hereinafter described.
The retorts are placed in a "bench" there being four for carbonising and four for
producing the water gas the latter however being worked in pairs. The water gas
retorts are each provided with two small fireclay pipes for the purpose of super-
heating first the steam drawn from any convenient source before it is passed into
the first retort and second the imperfect water gas produced in the first retort
previous to its passage into the second retort where it is converted into a perfect or
fixed water gas. The reason I make the water gas in two stages is because the
superheated steam is decomposed at a much lower temperature than carbonic acid
the carbonic acid and hydrogen being subsequently superheated to facilitate its
conversion into carbonic oxide.
For the purposes of this process hydrogen is required and is produced as will be
hereinafter described in upright retorts one being placed at each end of the furnace
said retorts being fitted with iron trays filled with spongy irons through which
superheated steam is passed for the purpose of making hydrogen while the com-
bined gas produced is ultimately carburetted to any desired degree of luminosity in
three or more retorts or chambers placed horizontally in the furnace. The object
of combining hydrogen with the water gas is to keep down the percentage of
carbonic oxide in the illuminating gas subsequently produced.
All these retorts, superheating pipes carburetting chambers and hydrogen
producing retorts are arranged in an oblong furnace of suitable dimensions."
One end of the inclined retorts and superheater pipes come through the side of
the roof of the furnace the lower ends of the retorts coming out through the front
of the furnace while the lower end of the superheater pipes communicate with the
lower end of the water gas retorts. Both ends of the retorts are provided with
suitable doors for charging and discharging.
Suitable arrangements are provided to allow the furnaces and retorts to expand
and contract without interfering the one with the other.
The furnace is by preference a gas fired one and is fitted with regenerators and a
reversing valve for air only, the gas employed being a waste gas which is taken hot
from the hydrogen producers, the production of hydrogen being for this purpose
stopped in one of the retorts to allow of a current of the fixed water gas passing
down same and out into the furnace the water gas re-converting at the time of its
passage the oxide of iron left, into metallic iron. During this period the production
of hydrogen is taking place in the other producer the operations being alternate as
hereafter described. The superheating pipes are fitted with fireclay or porcelain baffling
plates to increase their efficiency. The furnace has also 3 or more carburetting retorts
which are also fitted with somewhat similar baffling plates for the like purpose.
The gas produced in the first carbonisation of the coal or other material which has
been drawn away to the exhauster having previously had its tar and aqueous
vapours removed by washing and condensing is then forced back to the retort

page_text: bench where it is divided into six or more parts and used in six or more jets one in
each end of the carburetters of which there are three at each end of the furnace to
draw the water gas from the water gas retorts. It is important that this coal gas
should be cleansed as described as a great waste of hydro-carbon would sub-
sequently take place in the carburetting process caused by the decomposition of the
aqueous vapour the effect of which is to destroy the hydro-carbon used. The water
gas is carbonie oxide and hydrogen mixed with the hydrogen produced by decom-
position of superheated steam with the spongy iron as described and is forced by
these jets through pipes in the centre of the carburetting retorts from each end to
near the middle of the same where it then returns and finds its way to the outside
ends of the carburetter coming in contact with the butlling plates with which said
retorts are fitted. The jets of water gas serve to draw a supply of heavy petroleum
oil or the like into the carburetters where it is carried along in spray or vapour
with the gas in its passage through same.
In carlimretting I prefer doing it in three or more stages. In the first place the
total water gas and hydrogen with 3nd more or less) of the ordinary gas produced
in the first carbonization of the coal or other material will be carlmiretted up to a
certain point in the first carburetter a sufficient quantity of hydrocarbon oil or tar
being added for that purpose.
A second 3rd more or less) of the ordinary gas acting as a jet as described
under a slight pressure from the exhauster forces the gas from the first carburettor
through the second carburetter additional hydro-carbou oil or tar being here drawn
in as described. The last portion of the onlinary gas acting as a jet forces the gas
from the second carburetter again through the third carburetter into which also
the hydro-carbon oil is drawn.
By dividing the carburetting into three or more parts and adding the
carburetting material in three or more stages gas of any desired luminosity can be
made with the smallest amount of carburetting material.
The gas after passing through the last carburetter will be led away to coulers
scrubbers and purifiers and thence to the holder in the ordinary way.
It may be advantageous whenever the carburetting material is free from sulphur to
thoroughly purify both the gases before mixing and carburetting the same instead
of purifying subsequently,
To clearly explain my invention I will describe it with reference to the accom-
panying drawings which illustrate an apparatus I have found convenient for
carrying out my process where
Figure 1. (which is divided over Sheets 1. aud 2.) is a front view of the apparatus
partly in elevation and partly in section on the lines A. B. of Figure 2. and C. D.
of Figure 3.
Figure 2. (which is divided over Sheets 3. and 4.) is a plan one half however
being in section on the line E. F. of Figure 3.
Figure 3. is a section taken on the line G. 1. of Figure 1. and,
Figure 4. is an end elevation.
The letter A. indicates the interior of the furnace A' being the air regenerator
portion. B. are the four retorts used for carbonizing the coal in the first instance
said retorts being fitted with doors B' at the bottom and 13 at the top. A steam
pipe B is connected with the lower ends of these retorts for the purpose of
admitting steam into same for cooling the coke. The gas from these retorts is
drawn off through the pipes 13 into the hydraulic main B the end dipping into
the liquid to form a seal. C. C. are the two water gas retorts in which a portion
of the coke from the retorts B. is placed said retorts being provided with doors C
at the bottom and at the top. Steam is admitted into these retorts C. from the
steam pipes C (which are fitted in the heads C C of the superheating pipes C
through which it passes and enters the retorts C. by the pipes C C at the bottom
as shown in Figure 1. The superheating pipes C³ are fitted with baffling plates C'
(Figure 7) arranged round a central rod so that the steam is caused to take a
tortuous course in passing through same. The water gas from the retort C. passes

page_text: out through the pipes C' C' in the head of same and into the superheaters D³ D³
in the heads D D of which the pipes C' C' are fitted. These superheaters have
similar baffle plates to the pipes C. The gas now passes through the pipes D' D'
Figure 1. into the retorts D. which are charged with a portion of the coke from
the retorts B. and where it is formed into a fixed gas. The retorts D. are provided
with doors D' at bottom and doors D' at the top. From these the gas passes into
the pipe D and from thence into the horizontal carburetting retorts E. being
joined by a current of gas from the vertical hydrogen retort F. which is hereafter
described though it may also pass down into said retort F. when the generation of
hydrogen is not taking place. The carburetters E. are fitted with doors E' which
receive the various pipe connections.
The pipe D' which carries the gas passes into the first retort as shown in
Figure 4. at which point a pipe E enters same said pipe carrying the washed
illuminating gas which has been made in the retort B. and which is delivered under
pressure from the exhauster and passes into the carburetter through the nozzle E+
(Figure 1.) drawing with it the gas from the pipe D' and also a proportion of a
heavy carburetting oil from a branch pipe E of a main pipe E which oil is
delivered in the form of spray or vapour along with the gases. The carburetter
is fitted with a porcelain or metal tube E' (Figures 1. and 3.) having battle plates
arranged around same. The gas and carburetting material pass through the tube E.
and out at the end of same as shown by the arrows in Figure 1. returning past the
baffle plates by which it is enabled to take up a proportion of the oil. It then
passes out through the pipe Es into the second retort E. into which it is forced by
another jet of illuminating gas from a further pipe E which draws in at the same
time a proportion of oil from another branch pipe E passes through the retort and
out by the pipe E' into the third retort where it is also met by a further jet of gas
which forces it in together with more oil and after passing through the retort the
finished gas passes out through the pipe E to the usual coolers scrubber and
purifiers. The same operation takes place with the carburetters at the other end
of the furnace.
The hydrogen required is produced in the vertical retort F. which is fitted with
perforated iron trays F' holding spongy iron scrap or the like. A pipe F' leads to
this retort in which pipe a steam pipe F³ enters through which steam passes during
the time that hydrogen is being manufactured said hydrogen passing out through
the pipe D at the top of the retort as described. As soon as the steam from the
pipe is shut off (which is done by a valve not shown) the fixed water gas from
the retort D. enters the retort F. through the pipe D reconverting the iron oxide
formed by the hydrogen making process into metallic iron and passes out through a
valve (which is opened for the purpose) into a pipe F³ from whence it passes
through passages Fe into the furnace A. meeting at the same time the stream of
air from the regenerators A¹. It will be understood that the operation of making
the hydrogen and reconverting the oxide of iron and firing the furnace is alternated
at either end one of the valves Ds in the pipes D' being closed when hydrogen is
not being produced. I prefer to carry one end of all the inclined vertical and
horizontal retorts in the manner shown in Figures 1. and 3. in which it will be seen
that one end is formed of a casting G. having a sleeve portion and a flange with
which bolts H. engage said bolts having springs interposed between their nuts and
the flange to enable the retort to expand and contract. The other ends of the
bolts are held by the furnace casing in which at a point around the sleeves I place
pipes 1. in which water is caused to circulate to keep the ends of the retorts cool
and prevent them expanding.
By the process above described gas of any candle power can be made with the
smallest amount of hydrocarbon owing to the fact that gas making coal is used
instead of coke or anthracite coal all the hydrocarbons of same being utilized.
The carbonic oxide is kept down to a safe point by the addition of the hydrogen
produced as described.
It will be understood that I do not confine myself to the arrangement of the

page_text: retorts described or of the apparatus generally and I am also aware that it is not
new to introduce steam into the coal gas retort before withdrawing the coke and I
am also aware that it has been proposed to produce hydrogen by passing steam
through spongy irou and afterwards reconverting the oxide formed into imetallic
iron by passing carbonic oxide through same and I do not claim such as my
invention but
Having now particularly described and ascertained the nature of my inven
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. The process for the manufacture of illuminating gas which consists in making in
a retort ordinary coal gas cleansing saine and passing it into an exhauster, making
in a further retort a water gas by means of steam previously superheated passing
said gas through superheaters into a second retort for fixing, making hydrogen gas
in a further retort and passing the water gas and hydrogen into carburetting rotoris
by means of a jet or together with, a proportion of the coal gas substantially as
described.
2. In carrying out the above process carburetting the mixture of water gas,
hydrogen, and cleansed coal gas by passing same through a series of carburetting
retorts substantially as described.
3. In carrying out the process described in Claim 1. producing hydrogen by
alternately oxidizing iron by superheated steam and reducing the same to a metallic
state by the passage of a stream of a fixed water gas and utilizing the resulting
water gas to fire the furnace substantially as described.
4. In the manufacture of an illuminating gas a preliminary manufacture of water
gns in two stages substantially as described.
5. In the manufacture of illuminating gas from coal gas, water gas and hydrogen,
treating the coal gas in the first instance to completely remove the tar and aqueous
vapours substantially as described.
6. Apparatus for carrying out the process described in Claim 1. consisting of
coal gas retorts, water gas retorts, superheating pipes for the steam and water gas,
hydrogen retorts and carburetting retorts arranged in a furnace having air
regenerators said furnace being fired from either end alternately by the waste water
gus which is passed through the bydrogen retorts into same substantially as
described.
Dated this 9th day of March 1801
PHILIP M. JUSTICE,
55 & 50, Chancery Lane, London, Applicant's Agent.