IMPROVEMENTS IN THE MANUpacture of Gas FOR ILLUMINATING AND HEATING, AND IN APPARATUS EMPLOYED IN THE SAID MANUFACTURE
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Samuel Cornforth, Fredrick
Ratcliff, and William Henry Ratcliff at the Office of the Com-
missioners of Patents, with their Petition, on the 3rd November
1875.
We, SAMUEL CORNFORTH, of Birmingham, in the County of Warwick,
Manufacturer, and FREDRICK RATCLIFF, of Birmingham, aforesaid,
Engineer, and WILLIAM HENRY RATCLIPF, of Birmingham, aforesaid,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUpacture of Gas FOR ILLUMINATING AND HEATING,
AND IN APPARATUS EMPLOYED IN THE SAID MANUFACTURE," to be as follows :-
Our Invention consists in manufacturing the said gas by the com-
bustion or partial combustion of coal or other solid, from which the said
gas can be obtained by the action of heat, by conducting the said
combustion in a close retort or furnace, and effecting the combustion
by introducing a jet of steam and air or hot air, as herein-after
explained.

page_text: The retort in which the decomposition of the coal is effected may be
constructed of brick or any other convenient material, the walls of the
retort, if made of brick or earthenware, being sufficiently thick to
prevent risk of leakage. As the heat by which the decomposition of
the coal is effected is generated within the retort, the thickness of the
walls is of little consequence so far as economy of heat is concerned.
The said retort has at one side an opening capable of being closed air-
tight by a door or cover; at this opening the coal is charged into the
retort and the coke removed. The said retort has a false perforated
bottom, on which the coal is supported. The said false bottom is
sufficiently raised above the real bottom of the retort to permit of the
ready passage of the mixture of air and steam by which the combustion
and decomposition of the coal is effected. At the side opposite to that
at which the opening described is situated, and between the true and
false bottoms, a pipe opens into the space between the true and false
bottoms. The end of this pipe external to the retort terminates in a
short cross pipe, the ends of which are open to the atmosphere. A
conical jet fitted with a stop-cock capable of nice adjustment is fixed in
the top of the pipe described, and the said jet is connected with a steam
boiler generating steam of high pressure. The steam jet delivered into
the top of the pipe described passes to the space between the false and
true bottoms of the retort, carrying with it a current of air drawn in at
the cross pipe. The coal in the retort having been ignited before the
retort is closed, the combined jet of steam and air passes through the
false bottom of the retort into the fuel, and thereby maintains sufficient
combustion in the lower part of the coal to effect the complete decom-
position of the other portion of the coal, and thereby to produce
combustible gas. The gas produced passes off by a pipe at the summit
of the retort.
In order to promote the escape of the gas, and to overcome the
resistance of its passage through the hydraulic main and other parts of
the apparatus and the pressure of the gas holder, a steam jet may be
placed in an oblique position in the delivery pipe. This steam jet may
be regulated so as to withdraw the gas from the retort at the required
rate.

page_text: bottom a smaller jet of steam and air may be delivered on the upper
surface of the coal.
In place of a mixed current of steam and air a blast of hot air may
be substituted, the said hot air being delivered by a blowing engine. In
this case the upper jet of steam for driving off the gas is retained.