IMPROVEMENTS IN THE MANUFACTURE AND PURIFICATION OF GAS AND IN CERTAIN PARTS OF THE APPARATUS EMPLOYED THEREIN.
Year: 1871

page_text: LETTERS PATENT to George Eveleigh, of 16, Asylum Road, Peckham,
in the County of Surrey, Consulting Chemist, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE AND PURIFICATION OF GAS AND
IN CERTAIN PARTS OF THE APPARATUS EMPLOYED THEREIN.'
"
Sealed the 25th April 1871, and dated the 21st February 1871.
PROVISIONAL SPECIFICATION left by the said George Eveleigh at
the Office of the Commissioners of Patents, with his Petition, on
the 21st February 1871.
I, GEORGE EVELEIGH, of 16, Asylum Road, Peckham, in the County
of Surrey, Consulting Chemist, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE AND PURIFICATION
OF GAS AND IN CERTAIN PARTS OF THE APPARATUS EMPLOYED THEREIN," to be as
follows:-
My Invention relates to the manufacture and purification of gas
generated from coal, shale, bitumen, petroleum, turba, peat, wood, and in
some cases water, or other analogous substances, and refers in part to

page_text: certain improvements in the means and apparatus for which Letters
Patent were granted to me dated the 7th day of January 1869, No. 45.
My present improvements consist in distilling from one or more of
the substances, placed in a suitable retort, at the comparatively low
temperature of about 600° to 1000° Fahrenheit the best and richest
portions of the gas contained in such substances, together with the
oleagenous, tarry, and other vapourizable matters, the residue remaining
in the retort being coke of a superior quality suitable for foundry and
other purposes. The rich gas together with the said vapourizable
matters are conducted from the said retort by suitable pipes in a manner
somewhat similar to that ordinarily practised, but instead of the usual
hydraulic main I employ a large cooling tank wherein the chief portions
of the oily and other vapourizable matters which come over with the
gas are condensed as quickly as possible, allowing the rich gas to pass
on into a peculiar cooler and condenser of the following character :-
A large covered tank about half filled, more or less, with water receives
the gas upon the surface of the said water from the pipe leading from
the first-named cooling lank, which pipe may or may not dip slightly
into the water therein, the gas coming in contact with the oxtended
surface of water is still further freed from depositable substances, and
when thus freed becomes lighter, rises to the top of the tank, and
passes off at the opposite end by a pipe, the mouth of which rises nearly
to the top of the tank; this gas may then be further cooled if needful
by passing through pipes immersed in the water of the same or another
tank and from thence led to the lime or other purifiers. The larger
proportion of the olcagenous and other vapours which is, as above
stated, deposited or condensed in the first mentioned cooling tank,
and the remainder which is deposited or condensed in the second cooling
tank and condenser are then collected and conveyed into another tank,
from which they are caused to flow gradually into a heated pan where
they are revapourized at a suitablo temperature, and from whence the
vapours so reproduced are passed through one or more of the re-
distillation retorts charged with the chemical purifiers in the manner
described in the Specification of my said Patent of the 7th day of
January 1869. In the redistillation retort or retorts the said vapours
are converted into gas, which is more or less purified therein as may
be desired. From tlic redistillation retort or retorts, I pass the gas
through a cooling tank similar to that first above mentioned, containing
water, wherein any of the oil vapours which have not been converted

page_text: into gas by their passage through the redistillation retorts are again con-
densed and may be returned to the revapourizing pan and redistillation
retorts for further treatment, and so on again and again, until the wholo
is decomposed or only pitch remains in the revapourizing pan. From
the cooling tank this gas passes on to the condenser above described,
mixing on its way, if desired, with the rich gases coming over direct
from the first named distilling retort, and passing on with them to the
lime or other purifiers, and thence to the gas holder for use, or it may
bo kept distinct from the gases coming, direct from the retort, and
treated in a separate series of coolers, condensers, and purifiers if needful,
and passed direct to the gas holder. By this process I am enabled
to employ a low temperature in order to obtain the best and richest
portions of the gas from the coal, and by the treatment of the oily, tarry,
and other gas producing vapours in the manner described I fully
utilize them, and obtain the remainder of the gas which they contain,
and in most cases I by these means not only produce a larger total
quantity of gas from a given quantity of coal, but the illuminating
power and purity of the gas so produced are much greater than can
be obtained by the process heretofore practised, in which a great heat
is employed; the value of the residual products, such as the coke and
pitch, is also greatly increased.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Eveleigh in the Great Seal Patent Office
on the 19th August 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
EVELEIGH, of 16, Asylum Road, Peckham, in the County of Surrey,
Consulting Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of February, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George Eveleigh, Her special licence
that I, the said George Eveleigl, my executors, administrators, and
assigns, or such others as I, the said George Eveleigh, my executors,
administrators, and assigns, should at any time agree with and no

page_text: 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
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE AND PURIFICATION OF GAS, AND IN CERTAIN PARTS OF THE
APPARATUS EMPLOYED THEREIN," upon the condition (amongst others) that
1, the said George Eveleigh, 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 George Eveleigh, do hereby declare
the nature of my said Invention, and in what manner the saine is to be 1
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings
hereunto annexed.
My Invention relates to the manufacture and purification of gas
generated from coal, shale, bitumen, petroleum, turba, pent, wood, and
in some cases water or other analogous substances, and refers in part
10 certain improvements in the means and apparatus for which Letters
Patent were granted to me, dated the 7th day of January 1869, No. 45.
My present improvements consist in distilling from one or more of
the said substances in a suitable retort, at a comparatively low tem- 2
perature of about 600° to 1000° Fahrenheit, the best and richest portions
of the gas contained in such substances, together with the oleagenous,
tarry, and other vapourizable matters, the residue remaining in the
retort being coke of a superior quality. The rich gases, together with
the said vapourizable matters, are conducted from the said retort by 3
suitable pipes in a manner somewhat similar to that ordinarily practised,
but instead of the usual hydraulic main I employ by preference a largo
cooling tank, wherein the chief portions of the oily and other vapourizable
matters which come over with the gas are condensed as quickly as
possible, allowing the rich gas to pass on into a peculiar cooler and 3
condenser of the following character:-A large covered tank about
half filled, more or less, with water receives the gas upon the surface
of the said water from the pipe leading from the first-named cooling

page_text: tank, which pipe may or may not dip slightly into the water therein;
the gas coming in contact with the extended surface of water is still
further freed from depositable substances, and when thus freed becomes
lighter, rises to the top of the tank, and passes off at the opposite end by
a pipe, the mouth of which rises nearly to the top of the tank; this gas
may then be further cooled if needful by passing through pipes immersed
in the water of the same or another tank, and from thence led to the
usual lime or other purifiers. The larger proportion of the oleagenous
and other vapours which is, as above stated, deposited or condensed in
thic first-mentioned cooling tank, and the remainder, which is deposited
or condensed in the second cooling tank and condenser, are then col-
lected and conveyed into another tank, from which they are caused to
flow gradually into a heated pan, where they are revapourized at a
suitable temperature, and from whence the vapours so reproduced are
passed through one or more of the redistillation retorts charged with
the chemical purifiers in the manner described in the Specification of
my said Patent of the 7th day of January 1869. In the redistillation'
retort or retorts the said vapours are converted into gas, which is more
or less purified thercin as may be desired. From the redistillation
retort or retorts I pass the gas through a cooling tank similar to that
first above mentioned containing water, wherein any of the oily or other
vapours which have not been converted into gas by their passage
through the redistillation retorts are again condensed and may be
returned to the revapourizing pan and redistillation retorts for further
treatment, and so on again and again, until the whole is decomposed,
or only pitch remains. From the cooling tank this gas passes on to
the condenser above described, mixing on its way, if desired, with the
rich gases coming over direct from the first distilling retort, and passing
on with them to the lime or other purifiers, and thence to the gas holder
for use, or it may be kept distinct from the gases coming direct from
the retort and treated in a separate series of coolers, condensers, and
purifiers, if needful, and passed direct to the gas holder. By this
process I am enabled to employ a low temperature in order to obtain
the best and richest portions of the gas from the coal, and by the
treatment of the oily, tarry, and other gas producing vapours in the
manner described, I fully utilize them and obtain the remainder of the
gas which they contain, and in most cases I by these means not only
produce a larger total quantity of gas from a given quantity of coal, but
the illuminating power and purity of the gas so produced are much

page_text: greater than can be obtained by the ordinary process in which a great
heat is employed. The value of the residual products, such as the coke
and pitch, is also greatly increased.
Figuro 1 represents a sectional elevation on line a, a, of Fig. 2, of an
apparatus which I find suitable for carrying out the said process of
distilling rich gas at a low temperature from the coal or other sub-
stances, and the conversion into permanent gas of the oily, tarry, and
other gas producing vapours given off from the coal or other substances
with the gas; Figure 2 represents a plan of the same partly in section.
Figure 3 a half elevation and half vertical section of a bench of three
retorts.
Figure a vertical section on line b, b, of Fig. 1, through the
redistillation retort.
And Figure 5 a vertical section on line c, c, of Fig. 1, through the
revapourizing pan and its connections.
A, A, are the retorts in which the coal or other substance is placed for
distillation, these retorts I prefer to be of cast iron, they may be made
about 8 ft. long, 2 feet broad, and one foot four inches high of a D form
as shown; such a size is adapted to receive a charge of about 4 cwts. of
coal, if that be the substance employed. They may be set singly or in
benches of any convenient number, and in the ordinary manner. The
retorts are to be maintained at an equalized and uniform temperature
of from about 600° to 1000° Fahrenheit, or it may be in some cases
increased to 1300° according to the kind of coal employed. The charge
should be subjected to this heat for about 12 hours. A neck or pipe B,
which I prefer to be of a conical form as shown extends backwards from
the end of the retort, and is the outlet for the gas and vapours; it is
encased in brickwork so as to be shielded from the heat of the furnace
flues. This is necessary in order to prevent the said conical pipe from
becoming red hot, as if the rich gas given off in the retort is made to
pass through a red hot pipe, decomposition takes place more or less, and
a portion of the carbon contained in it is thrown down, and the illu-
minating power thereby reduced. The conical form of neck allows the
gas to pass away from the retort with less friction than a narrow straight
pipe. The outlet pipes B, C, D, convey the gas and vapours downwards
direct into the first cooling tank E in order to prevent the oil vapours
generated at the low temperature of the retort from becoming condensed
in them, and running back into the retort, which they are found to do

page_text: if made to rise therefrom in the manner usually practised with high
temperatures. The said first cooling tank E, which I prefer to employ
instead of the ordinary hydraulic main, receives the dip pipes from
the retorts below the water level F, and the outlet pipe G is placed
at the opposite side of the tank so that the gas issuing from the dip
pipes D, D, D, has to traverse over a large surface of water before
arriving at the outlet G, by this means it is quickly cooled, and the
larger portion of the oily and tarry substances are condensed more
quickly and certainly than they would be in the ordinary hydraulic
main, and fall to the bottom of the tank from whence they may be
drawn off by the dip pipe H and conveyed to the tar well by the pipe I,
to be treated as hercafter explained. The outlet pipe G conducts the
gas into the second cooler or condenser which may be of the ordinary
kind, or composed by preference of a large tank J with an inverted
bell or cover K which dips into the water of the tank so as to seal the
apparatus. The gas admitted by the inlet pipe L (which may or may
not dip into the water of the condenser) has to traverso over an extended
surface of water before arriving at the pipe M leading to the coil N, N,
by which the condensation is completed, and the gas is then passed on
to the purifiers by the pipe O in the ordinary manner. The oily and
tarry substances which fall to the bottom of the condenser are conveyed
therefrom to the tar well by the pipe P, similarly to those from the first
cooling tank. From the tar well they are conveyed by pumping or
otherwise into an elevated tank not shown, from which they are caused
to flow in a regulated quantity through a syphon R into a revapourizing
pan S, kept at a temperature of about 500° to 700° Fahrenheit. In
this pan the volatile constituents of the oils and tars are revapourized,
and they may be passed direct into the redistillation retort T which
is similar to those described in the Specification of my Patent A.D.
1869, No. 45, before referred to. But in this case I find the said
redistillation retort should not be more than 3 or 4 fect long, or of
only sufficient length to decompose the oil and other vapours, so that
the rich gas may be conveyed away as soon as possible after being
formed. I prefer, however, to pass the said vapours by the pipe U
into the intermediate chamber V, before allowing them to pass into
the redistillation retort. The intermediate chamber V is heated to a
temperature of about 700° to 900° Fahrenheit, it forms a trap in
which any pitchy or mucilagenous substance may be deposited which
might (in consequence of the application of too great a heat to the

page_text: revapourizing pan) have been carried over with the vapours. Any such
substances are conveyed back into the revapourizing pan S by means of
the pipe W, arranged as shown, or in any other convenient manner.
From the intermediate chamber the vapours are conveyed by pipe Vi
into the redistillation retort, which with its contents is heated by the
furnace X to a temperature of about 900° to 1300° Fahrenheit, according
to the speed with which the oil is admitted into the revapourizing pan,
which together with the intermediate chamber may be heated by the
waste heat from the furnace X somewhat in the manner shown, that is
to say, the heated gases generated in the furnace X after acting on the
charcoal cylinder T pass by the flues 1, 1, around and under the inter-
inediate chamber V, heating it to the required temperature, thence they
pass by flue 2 beneath the arch 3, 3, heating the cover of the revapour-
izing pan S. The heat reverberated downwards therefrom on to the
surface of the oil evaporates it from the upper surface thereof, the air
flues 4,4,4, keeping the pan cool below, so as to prevent ebulition,
which would cause the oil or tar to be carried over to the redistillation
retort in a fluid state. If preferred the revapourizing pan and inter-
mediate chamber may be heated by a separate furnace. The volatile
vapours which pass from the revapourizing pan through the intermediate
chamber pass on into the upper part of the redistillation retort and down
through the heated charcoal, etcetera, being thereby decomposed and
couverted into permanent gas, which passes through the false bottom
into the space beneath, and thence by the pipe Y to the cooling tank E',
which is similar in structure to that described in reference to the gas
resulting from the distillation of the coal. Any oil or tar vapours which
may have passed along with the gas through the redistillation retort
undecomposed are recondensed in this tank or the subsequent condenser,
are carried off to the far well by the pipes H', I', and may be passed
again and again through the revapourizing pan, intermediate chamber,
and redistillation retort, so long as any gas yielding substance remains
in them; or they may be used as drying oils for paints, varnishes,
etcetera. From the cooling tank E' the oil gas may be conveyed by the
pipe into the same condenser through which the coal gas is passed,
and being mixed therewith passes on to the purifiers along with it, or if
it is desired to keep the gas resulting from the oily and other matters
distinct from that resulting direct from the coal or other substances, a
separate condenser and purifiers are employed. Any suitable number of
redistillation retorts may receive the vapours produced in the revapourizing

page_text: pan, or each redistillation retort may be arranged with a revapourizing
pan and intermediate chamber, and each set so formed disposed side by
side, as shown in dotted lines in Fig. 2. By the use of the revapourizing
pan the pitch, or the greater portion thereof is deposited therein, and
does not enter the redistillation retort, consequently the charcoal does
not become blocked up with that substance, as sometimes happens when
the oil is admitted directly into the redistillation retort. The pitch may
be drawn off from the revapourizing pan from time to time by tho
pipe S' and deposited in the receptacle S. The revapourizing pan may
also with advantage be used in connexion with the redistillation retort
when producing gas therein from any fluid material, such as the
vegetable or mineral oils, or from liquifiable gas yielding solids, in order
to prevent any pitchy, resinous, or mucilagenous matters present in
them from entering the charcoal retort, and which matters are not
required in or are prejudicial to the formation of good illuminating gas,
and it is desirable to maintain its temperature, as before described,
somewhat lower than that of the redistillation retort.
I am aware that a low temperature has before been employed in order
to obtain a gas of high illuminating power and purity, but the methods
heretofore adopted have not been commercially successful, chiefly in
consequence of the small quantity of gas that could be produced by such
means.
By the means herein-before described I am enabled to produce an
aggregate quantity of gas equal to and in some cases greater than can
be obtained by the process now in use, in which high temperatures are
employed, while the illuminating power and purity are considerably
greater.
I am also aware that attempts have been made to produce gas from
hydrocarbon oils and tar, but heretofore they have been subjected to
destructive distillation after their formation at a high temperature,
wherchy very much of their valuable gas yielding qualities have been
sacrificed.
By the process herein described the hydrocarbon oils and tar are.
subjected to destructive distillation after they have been produced at a
low temperature and condensed so as to retain as much as possible of
the valuable qualities heretofore lost.

page_text: Having now described the nature of my said Invention and the
manner in which the same is to be performed, I would have it under-
stood that what I claim as my Invention is,―
First. The production of rich gas together with the oily, tarry, and
other gas producing vapours by the primary distillation, the treatment of 5
the said rich gas, and the oily, tarry, and other gas producing vapours
resulting from such primary distillation; and also the secondary dis-
tillation and treatment or conversion into permanent gas of the volatilo
constituents of such vapours, substantially as herein described.
Second. The general arrangement and adaptation of the retort, cooling 1
tank, and condenser composing the apparatus for effecting the primary
distillation and treatment of the rich gas and oily and other vapours,
substantially as herein described and shown.
Third. The revapourizing pan in connection with the redistillation
retort or retorts, substantially as and for the purposes described and 1
shown.
Fourth. The combination of the apparatus for effecting the primary
distillation and treatment of the rich gas and oily and other vapours
with that for effecting the secondary distillation and treatment or con-
version into permanent gas of the volatile constituents of the oily and 2
other vapours, substantially as described and shown.
In witness whereof, I, the said George Eveleigh, have hereunto
set my hand and seal, this Nineteenth day of August, in the
vear of our Lord 1871.
GEORGE EVELEIGH. (L.S.)
Witness,
W. H. BECK,
Consulting Engineer,
139, Cannon Street, London.