IMPROVEMENTS IN THE MANUFACTURE OF GAS AND IN THE PURIFICATION OF 'GAS LIQUOR,' AND IN UTILIZING GAS TAR AND CRUDE HYDROCARBON OILS, AND IN FURNACES FOR EFFECTING THE COMBUSTION OF THE SAID GAS TAR OR HYDROCARBON CILS
Year: 1868

page_text: LETTERS PATENT to Frank Clarke Hills, of the Chemical Works,
Deptford, in the County of Kent, Manufacturing Chemist, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF GAS AND IN THE
PURIFICATION OF 'GAS LIQUOR,' AND IN UTILIZING GAS TAR AND CRUDE
HYDROCARBON OILS, AND IN FURNACES FOR EFFECTING THE COMBUSTION OF
THE SAID GAS TAR OR HYDROCARBON CILS."
Sealed the 23rd June 1868, and dated the 25th April 1868.
PROVISIONAL SPECIFICATION left by the said Frank Clarke Hills
at the Office of the Commissioners of Patents, with his Petition,
on the 25th April 1868.
I, FRANK CLARKE HILLS, of the Chemical Works, Deptford, in the
County of Kent, Manufacturing Chemist, do hereby declare the naturė
of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF GAS AND
IN THE PURIFICATION OF 'GAS LIQUOR,' AND IN UTILIZING GAS TAR AND CRUDE
HYDROCARBON OILS, AND IN FURNACES FOR EFFECTING THE COMBUSTION OF THE SAID
GAS TAR OR HYDROCARBON OILS," to be as follows:-
My Invention relates, firstly, to the purification of gas from
sulphuretted hydrogen, carbonic acid, and the bi-sulphide of carbon

page_text: I effect the said purification by passing the gas through "gas liquor,"
which I purify and use in the following manner:-I take the said gas
liquor as it is produced and pass it through two or three or more boilers
or stills placed one at a higher level than another, so that the liquor
will run through suitable connecting pipes from one still to another.
The said stills should be kept about half or two-thirds full. Heat is
applied to the lower boiler or still and the liquor is made to boil. By
this boiling sulphuretted hydrogen and carbonic acid are driven off and
also some ammonia. These products are conveyed by a suitable pipe
from the first or lowest still into the second boiler or still which is
placed at a higher level, and the pipe conveying the said products dips
into the liquor in the second still so that the gases may come in contact.
with the said liquor as much as possible. A spreading diaphragm is
or may be placed at the bottom of the pipe so as to bring the gases
more in contact with the liquor in the still, which liquor must be kept
pretty hot by steam pipes or otherwise. I have found about 180°
Fahrenheit. to answer very well for my purpose. A good part of the
ammoniacal vapour which passes off from the first still with the gases
is taken up by the liquor, but most of the sulphuretted hydrogen and
carbonic acid gases pass through the liquor and escape into the third
still if three stills are employed. The pipe which conveys the gaseous
products from the second to the third still also dips into the liquor
contained in the latter, in the same manner as the pipe which conveys
the products from the first to the second still. Scrubbers filled with
coke may be used instead of the second and third stills, and the gas
liquor may be run as in the ordinary way through the said scrubbers
to meet the ascending products or gases, but I prefer the stills to the
scrubbers. The sulphuretted hydrogen, carbonic acid,, and other
products from the third still are conveyed to a furnace to be burnt
as far as practicable, and the waste products are passed to the chimney.
Any ammonia passing away with the escaping gases may be retained
by passing the said gases through a condenser or water scrubber on
their way to the chimney. The gas liquor when purified from the
sulphuretted hydrogen, carbonic acid, and other waste products (which
liquor when so purified is nearly caustic ammonia) is run hot from the
first still through pipes into tanks for use. The pipes conveying the
hot gas liquor from the lowest still are enclosed in other pipes through
which the cold gas liquor to be purified is caused to flow up to the
third still. The cold gas liquor will thus become hotter and hotter as

page_text: it passes between the outer pipes and the pipes conveying the hot
purified gas liquor from the first still to the tank, and will at the same
time cool the said hot gas liquor as it runs through the inner pipes, so
that by the time the liquors arrive at the ends of their respective pipes
the cold gas liquor has become hot and the hot gas liquor from the
first still has become cool. The gas liquor thus purified is to be used
for purifying the gas and may be applicable to other purposes. The
gas to be purified is passed through an ordinary scrubber filled with
coke or other suitable material in the usual way, and the. purified gas
liquor is run down through the scrubber also in the usual way to meet
the gas which passes upwards, and which will be thus to a considerable
extent deprived of its impurities. The purification of the said gas may
be finished in the usual way. If desired the gas liquor which has
become foul by use in the purification of gas as aforesaid may be repurified.
in the manner described and used again.
My Invention relates, secondly, to the utilization of gas tar or such
crude hydrocarbon oils as are applicable for burning in furnaces by
burning it or them in retort or other furnaces (constructed for or
adapted to the purpose, as herein-after described) in order to effect a
partial saving in the solid fuel used. When tar is used I distil from
it the most volatile oil or coal naptha; I effect this by filling a still
with tar to the required height, at which an outlet pipe is fixed, and
then running into the still at the bottom a regulated stream of crude
tar, and regulating the heat so as to distil off the required amount of
volatile oil or naptha. The tar deprived of this spirit will run out at
the outlet pipe so as to keep up a continuous process. I prefer to use
steam heat instead of fire heat as the former is safer.
The furnace in which the tar or crude oil is to be burnt is constructed
as follows:-That part of the furnace containing the solid fuel used may
be of the ordinary form. The front of the ash-pit is provided with
a tightly fitting door, and the floor of the said ash-pit slopes downwards
from the said door to the centre of the said ash-pit. Atmospheric air
instead of being admitted in front is admitted at the back or middle
of the ash-pit by means of a pipe or flue running through the side of
the said ash-pit. A transverse opening or slot communicating with the.
ash-pit is formed in the dead plate of the furnace. The tar or oil is
run in a regulated stream through a channel or pipe into the front
part of the ash-pit and will run down the sloping bottom thereof towards

page_text: the centre. The heat of the fire above distils the said tar or oil; the
greater portion of the vapour evolved passes up through and is burnt
by the said fire, and the portion of the said vapour which does not so
pass through the said fire passes through the opening in the dead plate
and is burnt as it passes over the said fire, atmospheric air being
admitted above the fuel (preferably through holes in the furnace door)
in order to effect the combustion of the said vapour. A portion of the
said vapour may be burnt in the ash-pit by allowing a sufficient quantity
of atmospheric air to pass into the said ash-pit by the side pipe or flue
herein-before referred to. I prefer to make gas furnaces (for the purpose
herein-before described) of the shape known as "V-shaped furnaces
without fire-bars, as any amount of heat may then be allowed in the
ash-pit. When bars are used they should be made hollow, and the cold
atmospheric air to supply the furnace and ash-pit should be passed
through the interior of the hollow bars to keep them as. cool as possible.
When the furnace is too wide to form a single V-shaped receptacle
for the fuel the said furnace may be composed of two or more V-shaped
receptacles.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frank Clarke Hills in the Great Seal Patent
Office on the 24th October 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANK
CLARKE HILLS, of the Chemical Works, Deptford, in the County of
Kent, Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of April, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Horself, Her heirs and successors, give
and grant unto me, the said Frank Clarke Hills, Her special licence
that I, the said Frank Clarke Hills, my executors, administrators, and
assigns, or such others as I, the said Frank Clarke Hills, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the

page_text: Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF GAS, AND IN THE PURIFICATION OF GAS LIQUOR, AND IN
UTILIZING GAS TAR AND CRUDE HYDROCARBON OILS, AND IN FURNACES FOR
EFFECTING THE COMBUSTION OF THE SAID GAB TAR OR HYDROCARBON OILS,"
upon the condition (amongst others) that I, the said Frank Clarke
Hills, my executors or administrators, by an instrument in writing
under my, or their, or one of their 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 same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Frank Clarke Hills, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say:-
My Invention relates, firstly, to the purification of gas (more or less
perfectly) from sulphuretted hydrogen, carbonic acid, and the bi-sulphide
of carbon. I effect the said purification by passing the gas through gas
liquor, which I purify and use in the following manner:-I take the
said gas liquor as it is produced and pass it through two, three, or
more boilers or stills or condensers placed one at a higher level
than another, so that the liquor will run through suitable connecting
pipes from one still to another. The said stills should be kept about
half or two-thirds full. Heat is applied to the lower boiler or still,
and the liquor is made to boil. By this boiling sulphuretted hydrogen
and carbonic acid are driven off and also some ammonia. These
products are conveyed by a suitable pipe from the first or lowest still
into the second boiler or still which is placed at a higher level, and the
pipe conveying the said products dips into the liquor in the second still,
so that the gases may come in contact with the said liquor as much as
possible. A spreading diaphragm is or may be placed at the bottom of
the pipe so as to bring the gases more in contact with the liquor in the
still, which liquor must be kept pretty hot by steam pipes or otherwise..
I have found about 180° Fahrenheit to answer very well for my purpose.
A considerable portion of the ammoniacal vapour which passes off from
the first still with the gases is taken up by the liquor, but the greater
portion of the sulphurretted hydrogen and carbonic acid gases passes
through the liquor and escapes into the third still if three stills are

page_text: employed. The pipe which conveys the gaseous products from the
second to the third still also dips into the liquor contained in the latter,
in the same manner as the pipe which conveys the gascous products from
the first to the second still. Scrubbers filled with coke may be used
instead of the second and third stills, and the gas liquor may be run as in
the ordinary way through the said scrubbers to meet the ascending products
or gases, but I prefer the stills to the scrubbers. The sulphuretted
hydrogen, carbonic acid, and other gaseous products from the third still
are conveyed to a furnace in connexion with a chimney be got rid of.
Any ammonia passing away with the escaping gases may be retained
by passing the said gases through a condenser or water or acid scrubber
on their way to the chimney. The gas liquor when purified from the
sulphuretted hydrogen, carbonic acid, and other waste products (which
liquor when so purified is nearly caustic ammonia) is run hot from the
first still through pipes into tanks for use. The pipes conveying the
hot gas liquor from the lowest still are enclosed in other pipes, through
which the cold gas liquor to be purified is caused to flow up to the
third still. The cold gas liquor will thus become hotter and hotter as it
passes between the outer pipes and the pipes conveying the hot purified
gas liquor from the first still to the tank, and will at the same time
cool the said hot gas liquor as it runs through the inner pipes, so that
by the time the liquors arrive at the ends of their respective pipes
the cold gas liquor has become hot and the hot gas liquor from the
first still has become cool. Instead of passing the gas liquor through
outer and inner pipes, as above described, the said gas liquor may be
passed through a vessel or heater containing a number of pipes, the
hot gas liquor being caused to pass outside the said pipes, and the
cold gas liquor being caused to pass through the said pipes, or vice
versa.
The accompanying Drawing represents in sectional elevation apparatus
for the purification of gas liquor according to my Invention.
A is a reservoir containing the gas liquor to be purified, which said
gas liquor passes through the pipe a' furnished with a stop-cock a² into
a heater B. The said heater consists of a vessel closed at both ends and
furnished with diaphragms b', 6', in which are fixed pipes 63, 62, through
which the cold gas liquor passes, the said pipes being surrounded by the
hot gas liquor passing through the heater to the tank, as herein-after
described. From the heater B the gas liquor passes through a pipe b³

page_text: to a still or condenser C, thence through a pipe c¹ into another still or
condenser D (where the said gas liquor is further heated by a bent
steam pipe d³), and thence through a pipe d' into a boiler E, which is
furnished with diaphragms e, e', for the purpose of better effecting the
distillation of the gas liquor, holes e³, e, being pierced in the said
diaphragms in order that the gas liquor and vapour may pass from one
compartment to another. The boiler E is kept at a boiling heat by a
bent steam pipe e³. e' is a pipe through which the purified gas liquor
passes to the heater B, and 6 is a pipe through which the said liquor
passes from the said heater to the reservoir or tank in which it is kept
for use; e, es, are pipes, the latter of which is furnished with a spreading
diaphragm e, through which pipes the ammonia and the sulphuretted
hydrogen and carbonic acid gases which are driven off by the boiling
pass to the still D. Here a considerable portion of the ammonia is taken
up by the liquor, but most of the sulphuretted hydrogen and carbonic
acid gases pass through the liquor and then through pipes d³, d³, the
latter of which is furnished with a spreading diaphragm d' into the
still or condenser C, whence the said gases after passing through the
liquor are conveyed by a pipe c³ to the furnace in connexion with
the chimney to be got rid of. The course of the gas liquor is indicated
by red arrows, and the course of the gases is indicated by black arrows.
Instead of passing the gas liquor through the heater B the said heater
may be dispensed with, and the cold gas liquor may be passed through
a pipe affixed upon and surrounding the pipe e', in which case the said
cold gas liquor will be conveyed from the reservoir A to the said outer
pipe by a branch pipe, a similar branch pipe being affixed to the other
end of the said outer pipe for the purpose of conveying the said gas liquor
to the still C. The gas to be purified is passed through an ordinary.
scrubber filled with coke or other suitable material in the usual way,
and the purified gas liquor is run down through the scrubber also in the
usual way to meet the gas which passes upwards, and which will be thus
to a considerable extent deprived of its impurities. The purification of
the said gas may be finished in the usual way. If desired the gas liquor
which has become foul by use in the purification of gas as aforesaid may
be repurified in the manner described and used again.
My Invention relates, secondly, to the utilization of gas tar or such
crude hydrocarbon oils as are applicable for burning in furnaces by
burning it or them in retort or other furnaces constructed for or adapted

page_text: to the purpose as herein-after described, in order thereby to effect a
partial saving in the solid fuel used. When tar is used I distil from it
the most volatile oil or coal naphtha which is too valuable to be burnt;
I effect this by filling a still with tar to the required height, at which
an outlet pipe is fixed, and then running into the still at the bottom
thereof a regulated stream of crude tar, and regulating the heat so
as to distil off the required amount of volatile oil or naphtha. The tar
deprived of this spirit will run out at the outlet pipe so as to keep up
a continuous process. I prefer to use steam heat instead of fire heat as
the former is safer.
The furnace in which the tar or crude oil is to be burnt is constructed
as follows:-That part of the furnace containing the solid fuel used
may be of the ordinary form. The front of the ash-pit is provided with
a tightly fitting door, and the floor of the said ash-pit slopes downwards
from the said door to the centre of-the ash-pit. Atmospheric air instead
of being admitted in front is admitted at the back or middle of the
ash-pit by means of a pipe or flue running through the side of the said
ash-pit. A transverse opening or slot communicating with the ash-pit
is formed in the dead plate of the furnace. The tar or oil is run in a
regulated stream through a channel or pipe into the front part of the ash-
pit and will run down the sloping bottom thereof towards the centre. The
heat of the fire above distils the said tar or oil; the greater portion of the
vapour evolved passes up through and is burnt by the said fire, and
the portion of the said vapour which does not so pass through the said
fire passes through the opening in the dead plate and is burnt as it
passes over the said fire, atmospheric air being admitted above the fuel
through holes in the furnace door or through side flues in order to
⚫effect the combustion of the said vapour. A portion of the said vapour
may be burnt in the ash-pit by allowing a sufficient quantity of atmo-
spheric air to pass into the said ash-pit by the side pipe or flue
herein-before referred to. I prefer to make gas furnaces (for the
purpose herein-before described) of the shape known as "V-shaped
furnaces" without fire-bars, as any amount of heat may then be allowed
in the ash-pit. When fire-bars are used they should be made hollow,
and the cold atmospheric air to supply the furnace and ash-pit should
be passed through the interior of the said hollow bars to keep them
as cool as possible. If preferred in the furnaces of gas retorts the tar
may be run on to the dead plate of the furnace, or on to fuel spread

page_text: on short bars used in lieu of a dead plate, and from thence any portion
that is not burnt will run through the furnace into the ash-pit, but in
this case an arch having its sides springing from the sides of the furnace
should be built over the dead plate to prevent the unburnt vapour of the
tar passing up the front flues of the said furnace, and no slot will be
required in the dead plate. When the furnace is too wide to form a
single V-shaped receptacle for the fuel the said furnace may be composed
of two or more V-shaped receptacles.
Having described the application of this part of my Invention to gas
retort furnaces, I do not think it necessary to describe its application to
other furnaces, as it will be sufficiently understood from the description
herein-before given.
Having now described the nature of my Invention, and the manner in
which the same is to be performed, I wish it to be understood that I do
not limit myself to the precise details herein-before described, as the
same may be varied without departing from the nature of my said
Invention, but I claim as my Invention,―
Firstly. Purifying gas liquor (more or less perfectly) from sulphuretted
hydrogen and carbonic acid gases by the process herein-before described
and illustrated in the accompanying Drawing.
Secondly. Purifying gas by passing it through gas liquor which has
been purified by the aforesaid process.
Thirdly. Utilizing gas tar and crude hydrocarbon oils by burning it or
them in the furnaces of gas retorts and in other furnaces in the manner
herein-before described.
In witness whereof, I, the said Frank Clarke Hills, have here-
unto set my hand and seal, this Twentieth day of October,
in the year of our Lord One thousand eight hundred and
sixty-eight.
Witness,
B. WILLCOX,
Clerk to H. H. Murdoch.
F. C. HILLS. (L.S.)