IM- PROVEMENTS IN THE MANUFACTURE OF ILLUMINATING GAS, AND IN APPARatus THEREFOR
Year: 1872

page_text: LETTERS PATENT to Abraham Malam, of Dumfries, in the County of
Dumfries, North Britain, Gas Engineer, for the Invention of "IM-
PROVEMENTS IN THE MANUFACTURE OF ILLUMINATING GAS, AND IN APPARatus
THEREFOR."
Sealed the 4th March 1873, and dated the 26th October 1872.
PROVISIONAL SPECIFICATION left by the said Abraham Malam at the
Office of the Commissioners of Patents, with his Petition, on the
26th October 1872.
I, ABRAHAM MALAM, of Dumfries, in the County of Dumfries, North
Britain, Gas Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF ILLUMINATING GAS, AND IN APPARATUS
THEREFOR," to be as follows, that is to say :-
This Invention has for its object to increase the quantity of illumi-
nating gas obtained from coal. It has been well understood that the
object referred to could be attained by applying to the retorts a greater
heat than that ordinarily employed were it not that with ordinary

page_text: apparatus the exit pipes are very liable to become choked when attempt
is made to increase the heat.
By one improvement comprised in the present Invention the difficulty
met with in using increased heat is overcome by cooling the exit pipe
and the part of the mouth piece of the retort to which the exit pipe is
attached. The exit pipe and mouth piece are formed by preference of
malleable cast iron, and a trough is formed on the mouth piece and
round the exit pipe. The trough is kept constantly supplied with water,
which keeps the top of the mouth piece and the exit pipe comparatively
cool, and thereby prevents the adherence of matters to the interior of the
exit pipe.
.A second improvement consists in taking the gas, more particularly
when obtained from cannel or similar rich coal after it has passed through
the condensers, and has consequently parted with its watery and heavy
tarry matters, and leading it through a second retort or set of retorts in
order that the light hydrocarbons which it contains in a state of vapor
or in suspension may be decomposed and completely gassified, thus
considerably increasing the bulk of permanent gas.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Abraham Malam in the Great Seal Patent Office,
on the 25th April 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ABRAHAM
MALAM, of Dumfries, in the County of Dumfries, North Britain, Gas
Engineer, 'send' greeting.
J
"WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of October, in the year.
of our Lord One thousand eight hundred and seventy-two, -in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said -Abraham - Malam,..Her
special licence that I, the said Abraham Malam, my executors,
administrators, and assigns, or such others as I, the said Abraham
Malam, my executors, administrators, and assigns, should at any time
with, and no others, from time to time and at all-times
agree
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an In-
vention for "IMPROVEMENTS IN THE MANUFACTURE OF ILLUMINATING Gas, and in
APPARATUS THEREFOR," upon the condition (amongst others) that I, the
said Abraham Malam, 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.
ALL
NOW KNOW YE, that I, the said Abraham Malam, 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 accom-
panying Drawings, that is to say :-
My said Invention has for its object to overcome some of the greatest
difficulties that have hitherto attended attempts to obtain increased
quantities of gas from coal by employing higher heats than those in
prevalent use. It has been well understood that a better yield of gas
would be satisfactorily obtainable by raising the heats were it not that
with ordinary apparatus increased heats lead to so much deposition of
earthy and adherent matter in the ascension or exit pipes leading from
the retorts às to frequently choke those pipes and necessitate inter-
ruptions in the working, thereby incurring serious inconvenience and
loss. By my present Invention I overcome the difficulties referred to
by providing apparatus or means whereby the exit pipe and the mouth
piece of the retort are kept in a comparatively cool state, and this has
the effect of preventing the inconvenient adherence of matters to the
inside of the exit pipe and mouth piece.
And in order that my said Invention and the manner of performing
the same may be properly understood, I hereunto append an explanatory
Drawing to be herein-after referred to, and representing the practical
application of my improvements in the case of "through" retorts,
which kind of retorts I prefer to use.
In the Drawing the retort or the main body 1 of it is shown as of
fire-clay, but it may be of cast iron if preferred. At one end an ordinary
mouth piece 2 is fitted, and the retort is charged and drawn at this end,
whilst at the other end there is fitted to it a mouth piece 3, which is by

page_text: preference of malleable cast iron, and which has the exit or ascension
pipe 4 attached to it. The ascension pipe 4 leads in the usual way by
branches 5, 6, into the hydraulic main 7. A trough or casing 8 is
formed on the mouth piece 3 and round the lower part of the exit pipe 4,
and is kept filled or partly filled with water. An annular gutter 9 is
formed round the upper part of the pipe 4, and a regulated stream of
water being led into it from a supply pipe finds its way through perfora-
tions in the bottom of the gutter, and streaming down the outside of
the pipe assists in keeping it cool. The cooling action is increased and
deposition further prevented by introducing a small regulated quantity
of water into the interior of the exit pipe 4, this water being admitted
by a pipe 10, and being spread by first falling on a disc 11, so as to wash
down the sides of the pipe. In order that the mouth piece 3 may not be
filled up by deposited matters washed down from or prevented from
entering the the exit pipe 4 an outlet with a basin-shaped funnel 12 is
fitted in the bottom of the mouth piece, and communicates by a pipe 13
with a receiving trough 14, which is always kept sufficiently filled with
water to seal the end of the pipe 13.
The improvements herein-before described can easily be applied to
various forms or kinds of retorts; and when the retort is single or such
as to
open at one end only the funnel 12 may be removed during drawing
and charging, or the top of it may be made flush with the bottom of
the mouth piece 3, and be covered by a plate during drawing and
charging.
In my Provisional Specification deposited with my application for the
herein-before in part recited Letters Patent I referred to the leading
of the gas through a second retort or set of retorts after having
passed through the condensers in order that any condensable hydro-
carbons might be decomposed and completely gasified. I do not however
now desire to retain any claim for such process, but prefer to attain the
same ends to a great extent by a simpler, more convenient, and more
economical arrangement. I have the retort formed with an internal
shoulder or contraction 15, and when charging the retort I first rake
against the shoulder a portion of the incandescent coke of the previous
charge, and the newly formed gas is compelled to pass over and through
this incandescent coke on its way to the exit pipe, in consequence of
which only very small quantities of condensable hydrocarbons can pass
off without being decomposed and thoroughly gasified.

page_text: Having thus particularly described my said Invention and the manner
of performing the same, I have to state that I do not restrict myself to
the precise details herein described or delineated, but 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, the keeping of the
exit or ascension pipes and mouth pieces of retorts used in making
illuminating gas in a comparatively cool state for the purpose and by
means substantially such as those herein-before described.
In witness whereof, I, the said Abraham Malam, have hereunto set
my hand and seal, this Twenty-third day of April, in the year
of our Lord One thousand eight hundred and seventy-three.