IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF GAS FOR HEATING OR OTHER PURPOSES,
Year: 1875

page_text: LETTERS PATENT to Joshua Kidd, of 12, Dartmouth Street, in the
City of Westminster, Engineer, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OR PRODUCTION OF GAS FOR HEATING OR OTHER PURPOSES,
PROVISIONAL SPECIFICATION left by the said Joshua Kidd at the
Office of the Commissioners of Patents, with his Petition, on the
13th February 1875.
I, JOSHUA KIDD, of 12, Dartmouth Street, in the City of Westminster,
Engineer, do hereby declare the nature of the said Invention for "Iм-
PROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF GAS FOR HEATING OR OTHER
PURPOSES, AND IN THE MATERIALS AND APPARATUS OR MEANS EMPLOYED THEREIN,”
to be as follows:-
This Invention relates to an improved mode of and apparatus for
manufacturing or producing gas in a simple and economical manner, to
be used for heating or other purposes, and consists essentially in the

page_text: generation of a mixture of carbonic oxide, hydrogen, and carburetted
hydrogen gases from peat or wood charcoal or mixtures of the same, or
from high dried or charred peat, either alone or mixed with other solid
fuel. When using high dried or charred peat I prefer to employ that
which has been produced by the method described in the Specification
of Letters Patent granted to Arthur Barff on my behalf, and bearing
date the 12th of February, 1873, No. 520. The charred peat is placed
in a furnace or chamber which is closed at the bottom and top so as to
exclude the external atmosphere. Into a closed ash-pit formed under
the grate bars of the said furnace or chamber I inject a mixture of air
and steam, using by preference dry or slightly superheated steam.
The gases generated by the decomposition of the air and steam on
coming in contact with the incandescent charred peat fuel are conveyed
away from the top of the furnace or closed chamber by a pipe which
may either lead direct to a gas holder or to any locality where the gas is
required to be burned. It has been found in practice that this method
of producing gas is also applicable to coal or coke when used alone or
mixed together, but I have discovered that as charred wood or peat has
a greater affinity for oxygen it is the only kind of fuel which will give
satisfactory results.
The fuel is supplied continuously to the interior of the chamber or
furnace from a vertical hopper fitted with a lid or cover. The shell of
the said chamber or furnace may be of any convenient shape, and made
either fixed or portable, and may be constructed either of sheet or cast
iron, and lined with fire-brick.
In starting the apparatus a small quantity of the fuel is to be heated
to incandescence in a separate fire and then deposited on the grate bars
of the closed chamber or furnace, and the jet of steam immediately
turned on. This steam may be generated by the heat contained in the
gases collected in the upper part of the closed chamber or furnace, or
may be supplied from a separate steam generator.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joshua Kidd in the Great Seal Patent Office
on the 13th August 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSHUA
KIDD, of 12, Dartmouth Street, in the City of Westminster, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of February, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Joshua Kidd, Her special
license, that I, the said Joshua Kidd, my executors, administrators, and
assigns, or such others as I, the said Joshua Kidd, 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
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN THE MANUFACTURE OR PRODUCTION OF GAS FOR HEATING OR OTHER PURPOSES,
AND IN THE MATERIALS AND APPARATUS OR MEANS EMPLOYED THEREIN," upon the
condition (amongst others) that I, the said Joshua Kidd, 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 Joshua Kidd, 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, reference being had to the accom-
panying Drawing hereunto annexed, and to the letters and figure
marked thereon, that is to say :—
My said Invention consists in combining a gas producing furnace
with a steam generator and in changing solid into gaseous fuel by
forcing a current of dry steam and air through a thick mass of incan-

page_text: descent fuel placed in a closed or partially closed furnace; and, further,
in so arranging the apparatus that it can be changed at once either into
a quick or slow combustion furnace, or into a gas producer, as may
be
required.
My apparatus consists essentially of a furnace having a closed fire-box
and ash-pit combined with a steam generator situate inside the said
furnace or ash-pit, and composed of a series of vertical tubes connected
together at the top and bottom or consisting of a coil of iron pipe.
Water is supplied to the lower part of the generator from a tank
sufficiently elevated to maintain a steam pressure of from 10 to 20 lbs.
I have found as the pressure of steam is increased that the working of
my furnace is improved. The heat from the imperfect combustion of
the fuel acts upon the upper parts of the tubes and heats the water
principally at the top of its vertical column or in the upper coils of the
pipe and generates steam, which thus becomes slightly superheated, and
as the pressure increases it drives the water from the hottest part of the
generator back to the supply tank, and vice versa. The steam from the
generator is made to escape from a jet placed opposite a tube fixed in
the ash-pit.
The gas generated in this furnace consists chiefly of carbonic oxide
and hydrogen gases mixed with a large proportion of nitrogen. The
fuel used may be coal, coke, breeze, wood, or peat charcoal, or high
dried or partially charred peat. Carbonic acid gas is first formed from
the combustion in the lower layer of incandescent fuel, which becomes
changed into carbonic oxide during its passage through the upper layers
of the fuel; the steam also becomes decomposed into carbonic oxide and
hydrogen. The gases thus generated from the decomposition of the
solid fuel and steam escape with considerable force from a contracted
orifice placed at or near the top of the closed furnace, and may be
conveyed direct to a gas holder or to any locality where the gas is
required.
In applying my improvements to present gas producing furnaces I
simply close the ash-pit and inject air into the same under the fuel by
the escaping force of a jet of dry steam.
And in order that my said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the Figure on the annexed Sheet of Drawings, which

page_text: represents a sectional elevation of my improved gas producing furnace
and steam generator combined.
a shows a closed or partially closed cylindrical furnace or fire-box, and
6 the closed ash-pit; c, c, the steam generator. This generator may be
5 formed of vertical tubes joined at the top and bottom, or may consist of
a coil of iron pipe, as shown in the Drawing. d, the water inlet from
an elevated tank to the generator; e, the steam jet pipe, the escaping
force of the steam from which forces or induces air into the ash-pit
through the short pipe f; g is the plug for closing the gas outlet g¹ when
the apparatus is not used as a gas generator; h is a moveable door to the
ash-pit, supported by the adjustable rack i and a detachable hinge so
that if necessary it can be removed; j, j, are the grate bars; k, the
opening into the furnace for facilitating the operating and lighting of
the fire; this opening is closed with a gas-tight cover l; m is a moveable
gas-tight lid for admitting fuel into the furnace; n is the fuel box ; o, the
inlet for fuel; p, the cover fitted with a projecting shield q for preventing
զ
the fuel from falling on to the gas-tight lid m; r is the outlet to the
chimney; 8 is a damper; t, a sheet-iron cylinder or frustum of a hollow
cone made fast to the top of the furnace a and open at the bottom
) where it projects into the centre of the furnace for preventing the fuel
coming in contact with the steam generating tubes; v, a fire-clay or
any other non-conducting material surrounding the lower part of the
steam generating coil.
In starting this furnace the lid m and ash-pit door ŉ should be open
and the fire lighted, when it will burn as in an ordinary stove. When
using this apparatus as a slow combustion furnace only the lid m should
be opened and the ash-pit door h nearly closed. When it is required to
make the furnace a gas producer then I close the lids m and h and turn
on the steam jet, taking care there is a sufficient thickness or depth of
) fuel in the furnace before starting. Should it be desired to increase the
heating power of the gas I place a coil made like the coil o (but some-
what smaller) in the ash-pit or at the gas outlet, where the said coil can
be heated by the radiated or waste heat of the furnace. In this coil I
vaporise petroleum or naptha, and allow the vapor to mix with the gas
escaping at g. This coil for generating hydrocarbon vapour is supplied
with the liquid hydrocarbon and operated exactly the same as the coil c.
To feed the furnace fuel is placed in the box n, the lid m is raised to the
top, and the projecting piece or shield q with the cover p is turned partly

page_text: round so as to uncover the outlet of n when the fuel will drop into the
furnace. During the operation of feeding the damper 8 should be
closed.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider to
be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,―
First. The combination of the steam generator c for supplying a jet of
steam with the said closed or partially closed gas producing furnace
when the said generator and furnace are constructed and arranged to
operate together, substantially as and for the purpose herein-before
described.
Secondly. The combining with the said closed or partially closed gas
producing furnace all or any one or more of the parts marked c, e, f, t,
h, m, v, n, and g, or their equivalents, substantially as herein-before
described, when used for the purposes set forth.
Thirdly. The peculiar method herein set forth of generating a gas
suitable for heating purposes by the aid of apparatus substantially such
as is herein-before described and illustrated by the Drawing.
Fourthly. The application and use of charred or high dried peat to
and in the manufacture of gas for heating purposes, 'substantially in the
manner herein-before described.
In witness whereof, I, the said Joshua Kidd, have hereunto set
my hand and seal, this Ninth day of August, in the year of our
Lord One thousand eight hundred and seventy-five.
Witness,
JOSHUA KIDD. (L.S.)
EDWIN P. ALEXANDER,
Consulting Engineer and Patent Agent,
14, Southampton Buildings,
Chancery Lane, W.C.