IMPROVEMENTS IN MAKING ILLUMINATING GAS, AND IN APPARATUS THEREFOR.
Year: 1871

page_text: LETTERS PATENT to John Fleming Allan, of Glasgow, in the County
of Lanark, North Britain, for the Invention of "IMPROVEMENTS IN
MAKING ILLUMINATING GAS, AND IN APPARATUS THEREFOR.'
"
Sealed the 14th July 1871, and dated the 16th January 1871.
PROVISIONAL SPECIFICATION left by the said John Fleming Allan
at the Office of the Commissioners of Patents, with his Petition,
on the 16th January 1871.
I, JOHN FLEMING ALLAN, of Glasgow, in the County of Lanark;
North Britain, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MAKING ILLUMINATING GAS, AND IN APPARATUS THEREFOR,"
to be as follows:-
د,
. This Invention has for its object the making of illuminating gas in
larger quantity, of better quality, and by simpler and more easily
managed apparatus than heretofore. And it consists, in the first place,
in dispensing with the ordinary hydraulic main, and so removing
pressure from the retorts without the aid of gas exhausters ordinarily
used for that purpose.

page_text: The Invention also comprises a peculiar conjoint and compact
arrangement of retort furnace, tar separator, and purifier in one self-
contained cast-iron casing, capable of being made of various sizes,
and suitable either for country or other single houses, or for larger
establishments.
.
The retort furnace consists of a rectangular cast-iron casing lined with
fire-brick, and fitted with a gas retort, by preference of cast iron, which
retort does not quite reach the inner end of the casing, so that the fire
gases pass up at the inner end, and being led forward along a flue over
the top of the retort enter a chimney or uptake near the front end. The
gas passes off from the front end of the retort by a short vertical pipe,
the top of which enters a box containing a nicely balanced flap valve,
which closes on the retort being opened for charging, and prevents the
return of gas. From the valve box the gas is led by a pipe so as to
enter in a downward direction a cast-iron casing constructed at the side
of the furnace casing, and acting as a separator of and reservoir for the
tarry liquids condensed from the gas. A purifier or vessel for containing
any suitable known purifying agent or agents is fitted upon the tar
reservoir, and the gas passing up through it is finally led to the gas-
holder. The apparatus is for making gas from coal or other suitable
carbonaceous material.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Fleming Allan in the Great Seal Patent
Office on the 14th July 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN 2
FLEMING ALLAN, of Glasgow, in the County of Lanark, North Britain,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of January, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty- 3
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Fleming Allan, Her special
licence that I, the said John Fleming Allan, my executors, adminis-
trators, and assigns, or such others as I, the said John Fleming Allan,
my executors, administrators, and assigns, should at any time agree a

page_text: "}
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 Channel Islands,. and Isle of Man, an Invention for
"IMPROVEMENTS IN MAKING ILLUMINATING GAS, AND IN APPARATUS THEREFOR,"
upon the condition (amongst others) that I, the said John Fleming
Allan, 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 John Fleming Allan, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement in writing, reference being had to the
accompanying Drawings, that is to say:-
My said Invention has for its object the making of illuminating gas
in larger quantity, of better quality, and by simpler and more easily
managed apparatus than heretofore. And it consists, in the first place,
in dispensing with the ordinary hydraulic main, and so removing
pressure from the retort without the aid of gas exhausters ordinarily
used for that purpose.
My Invention also comprises a peculiar conjoint and compact
arrangement of retort furnace, tar separator, and purifier in one self-
contained cast-iron casing or structure, capable of being made of various
sizes, and suitable either for country or other single houses, or for larger
establishments.
And in order that my said Invention and the manner of performing
the same may be properly understood I hereunto append a Sheet of
explanatory Drawings to be herein-after referred to, and representing a
modification of my improved apparatus suitable for a country house.
Figure 1 is a plan, Figure 2 a vertical section, and Figure 3 a sectional
front elevation.
The retort furnace consists of a rectangular cast-iron casing 1 lined
with fire-brick, and fitted with a gas retort 2, by preference of cast iron,
which retort does not quite reach the inner end of the casing 1. The

page_text: fire gases from the grate. 3 pass along the space 4 under the retort 2.
towards the back, and rising up at the back end 5 are led forward along
a flue 6 over the top of the retort to a chimney or uptake. 7 near the
front end. The gas passes off from the front end of the retort 2 by a :
pipe 8, which dips down through the cover of a cast-iron casing.9 con-
structed at the side of the furnace casing 1, and acting as a separator of.
and reservoir for the tarry liquids condensed from the gas.
I intended to have employed a self-acting valve in connection with
the gas exit pipe 8, but finding by practical trial that such valve was
liable to derangement from the accumulation of tar on it I have modified
the arrangement so as to overcome the difficulty. The valve which I¸
find most suitable is one to be operated by hand, and carries out more
completely than my proposed self-acting valve the object I had in view
of avoiding all pressure or resistance to the exit of the gas from the
retort. The valve is in the form of a cup 10 suspended below the bottom.
of the pipe 8 by a pair of rods 11 passing out through stuffing boxes to
a hand lever 12. This cup is partly filled with liquid, and when in the;
position in which it is shown closes the pipe 8, but on being lowered by
means of the handle 12 provides a perfectly free passage for the gas.
The tar separating casing 9 is fitted with vertical partitions 13 arranged.
as indicated by dotted lines in Figure 1, so as to cause the gas to traverse
over an elongated course. An overflow siphon 14 is provided for the
tarry liquids to pass off by as they accumulate, this siphon being fitted
to the front compartment of the casing, which compartment is separated
from the rest of the casing by a partition 13 going completely across,
but open at the top at the side furthest from the inlet pipe 8. This
front compartment is not supplied with water, but water is put into the
other part of the casing where the partition plates do not extend down
to the bottom, but only dip a short distance below the water level. At
the back end of the tar separating vessel 9 a purifier 15 is placed, and
is provided with a number of perforated trays 16 on which to put any
suitable known purifying agent or agents, and the gas permeating
upwards through this purifier finally passes off by a pipe 17 to the gas
holder. The apparatus is for making gas from coal or other suitable
carbonaceous materials.
Having thus particularly described my said Invention, and the manner
in which the same is to be performed, I have to state that I do not
restrict myself to the precise details herein. described or delineated; but

page_text: that what I believe to be novel and original, and claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,―
-
1. The arranging or combining together of the parts of apparatus for
making illuminating gas substantially in the improved manner herein
described and delineated.
2. The making of illuminating gas by means of apparatus arranged
without hydraulic mains or exhausters, but so as to oppose no resistance
or pressure to the exit of the gas from the retorts, as herein-before
described.
In witness whereof, I, the said John Fleming Allan, have hereunto
set my hand and seal, this Thirteenth day of July, in the year of
our Lord One thousand eight hundred and seventy-one.
JOHN F. ALLAN. (L.S.)