Year: 1887

page_text: Date of Application, 17th May, 1887
Complete Left, 15th Feb., 1888
Complete Accepted, 23rd Mar., 1888
I, JAMES KEITH of 57 Holborn Viaduct, in the City of London, Gas, Hydraulic,
Heating and Ventilating Engineer, do hereby declare the nature of this invention to
be as follows:-
My invention relates to gas making apparatus of the kind described in the
Specifications of Letters Patent granted to me Nos. 1066 of 1874 and 2091 of 1881,
the present improvements having reference to the construction and arrangement of
the retorts and retort chambers or furnaces of such apparatus and being specially
designed for use in the manufacture of gas on a small scale from mineral or other
oils.
The retort under the invention consists of a pipe of cast iron or other material
composed of two branches laid horizontally at a slight inclination the one to the other
and united at one end so that they constitute two sides of a triangle. The end
towards which the branches converge is open and formed with a flange whereto a
cleaning door is fitted and at the opposite end one branch is provided with means for
admitting the oil to be distilled and the other with a suitable connection to the usual
ascension pipe, the gas which is generated by distillation of the oil entering at one
end of the retort being by this arrangement carried from front to rear of the retort
and thence returning to the ascension pipe in front and being by the continued
application of heat freed from oil or condensible fumes. The pipe of which the
duplex retort is composed is preferably of D-shape in cross section and it is rested on
its flat side upon a slab of fire clay or similar refractory material carried longitudinally
through the combustion chamber of a furnace, the slab being made of U-section or of
tubular form and having at the upper side near the front and between the branches
of the retort an opening through which the products of combustion enter and at its
rear end an opening through which said products are discharged into a smoke stack
connected to it, a cleaning door being provided in front. The furnace and combustion
chamber form a box, near the lower end of which is situated the fire grate to which
access is had through a doorway in front; and the flame and fire gases rising from
the fire grate pass upward between the side walls of the combustion chamber and the

page_text: hollow fire clay slab, over the top of the retort, between the retort branches and
through the hollow slab to the outlet, the retort being protected from the direct heat
of the fire, whilst its ends, in which are the openings to give access for cleaning,
extend beyond the furnace walls. The furnace and retort walls, the ceiling of the
oven, and the hollow rest for the retort, are by preference made each of single slabs
of fire clay but they may be built up of fire bricks or similar refractory material and
the whole may be enclosed in a cast iron casing provided with orifices for the several
doorways of the retort and furnace. Two or more of the duplex form of retorts may
be combined, or additional branches may be formed on it to provide a longer course
for the gas subjected to the heat of the furnace.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Manufacturing Oil Gas.
I, JAMES KEITH of 57 Holborn Viaduct in the City of London, Gas, Hydraulic,
Heating and Ventilating Engineer do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My invention relates to gas making apparatus of the kind described in the
Specifications of Letters Patent granted to me Nos. 1066. of 1874 and 2091 of 1881
the present improvements having reference to the construction and arrangement of
the retorts and retort chambers or furnaces of such apparatus and being specially
designed for use in the manufacture of gas on a small scale from mineral or other
oils.
The retort as constructed under the invention and as represented in the accompanying
drawings in longitudinal and transverse vertical sections at figures 1 and 2 and in
horizontal sections at figures 3 and 4 consists of a pipe of cast iron or other material
composed of two branches A, A', laid horizontally at a slight inclination the one to
the other and united at one end so that they constitute two sides of a triangle. The
rear end towards which the branches converge is open and formed with a flange a
whereto a cleaning door is fitted and at the opposite or front end one branch A is
provided with means such as the usual drip pipe for admitting the oil to be distilled
and the other A' with a suitable connection to the usual ascension pipe B the gas
which is generated by distillation of the oil entering at one end of the retort being by
this arrangement carried from front to rear of the retort and thence returning to the
ascension pipe in front and being by the continued application of heat freed from oil
or condensible fumes. The pipe A, A¹ of which the duplex retort is composed is
preferably of D shape in cross section and it is rested on its flat side upon a slab C of
fire clay or similar refractory material carried longitudinally through the combustion
chamber D of a furnace the slab being made of U section or of tubular form and
having at the upper side near the front and between the branches of the retort an
opening E through which the products of combustion enter and at its rear end an
opening F through which said products are discharged into a smoke stack G
connected to it, a cleaning door H being provided in front. The furnace and
combustion chamber D form a box near the lower end of which is situated the fire
grate I to which access is had through a doorway J in front; and the flame and fire
gases rising from the fire grate pass upward between the side walls D¹ of the
combustion chamber and the hollow fire clay slab Cover the top of the retort,
between the retort branches A, A³, and by the opening E through the hollow slab (
to the outlet G, the retort being protected from the direct heat of the fire whilst its
ends, in which are the openings giving access for cleaning, extend beyond the furnace
walls.
The furnace and retort walls, the ceiling of the oven and the hollow rest for the
retort are by preference made each of single slabs of fire clay but they may be built

page_text: up of fire bricks or similar refractory material and the whole is or may be enclosed in
a cast iron casing K provided with orifices for the several doorways of the rotort and
furnace. Two or more of the duplex form of retorts may be combined or additional
branches may be formed on the retort to provide a longer course for the gas subjected
to the heat of the furnace.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. The combination of parts constituting the improved apparatus heroinbefore
described for manufacturing oil gas.
2. In apparatus for manufacturing oil gas a duplex retort constructed substantially
as hereinbefore described.
3. In apparatus for manufacturing oil gas a hollow retort rest or slab constructed
and arranged to constitute an outlot for the heating furnace gases substantially as
hereinbefore described.
Dated this Eleventh day of February 1888
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.