Year: 1887

page_text: Date of Application, 24th Jan., 1887.
Specification Accepted, 12th July, 1887.
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
M.I.M.E., 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 :-
The properties which hydrogen possesses of developing by its combustion an
excessive and intense heat its great affinity for oxygen and its capacity when heated
for reducing metallic oxydes and sulphurets suggest a utilization of this gas in contact
with the substances to be treated.
Hydrogen gas may be practically produced from olefiant gas and steam which
become decomposed when in contact with highly incandescent coke. The olefiant gas
is obtained by the distillation of coal the decomposition of the gas being effected by
causing it to traverse the highly incandescent coke of the same furnace which effected
the distillation (see Ebelmans experiments). The olefiant gas in contact with slightly
incandescent coke becomes decomposed into carbon and marsh gas; the latter requires
for its combustion a very elevated temperature and does not possess to any degree the
heating and reducing power of bydrogen which requires for its combustion eight
kilogrammes of oxygen for one kilogramme of hydrogen whilst a kilogramme of marsh
gas only requires four kilogrammes of oxygen the latter developing 13063 units of
heat (calories) only whilst the hydrogen produces 31462. It follows therefore that the
olefiant gas must be decomposed into carbon and hydrogen that is to say by causing it
to pass through highly incandescent coke.
It is known that in a cupola the products of combustion are not entirely decomposed
until at a distance of about one metre from the blast. It therefore follows that the
olefiant gas when the draw off is established at this distance above the blast can only
come in contact with a mass of coke slightly incandescent found above this distance in
the shaft and be decomposed into carbon and marsh gas.

page_text: In consideration of the facts stated I dispose the draw off in the furnace serving as
a generator below the blast tuyeres. In this manner the gas of the shaft passes
through a mass of highly incandescent coke in the zone of combustion thus assuring
the complete decomposition of the carburets into carbon and hydrogen and the
production of a highly superheated gas.
In order to vary the temperature and the composition of the gases several series of
tuyeres may be arranged one above the other to send the blast in at different heights
at will either successively or simultaneously so as to vary the height of the high
temperature zone.
For this purpose each tuyere is furnished at its orifice with a sliding iron door
which is controlled through a corresponding opening in the outer wall of the air
chamber which is also provided with a similar door glazed with blue glass.
The current of gas in traversing the zone of combustion can come into contact with
the oxygen and can give rise to a production of carbonic acid and steam but in the
principle cited the reduction of these gases into carbonic oxyde and hydrogen
commences afresh in contact with the highly incandescent coke found below.
In order to separate the gaseous currents the jets of air are set strongly inclined and
tangential to a cylinder having the same axis as the furnace; the gases produced at
the buyeres are thus propelled towards the hearth of the furnace and the gases of the
shaft descend along its axis forming a central cylindrical current. If the generator
be designed to produce gas under pressure and in consequence has to be fed with air
under high pressure a sensible increase of temperature will follow which may be
profitably utilized to effect the decomposition of a jet of steam; the percentage of
hydrogen in the gas being thus increased at the expense of the intensity of heat at the
zone of combustion.
In the accompanying drawings are represented two different constructions of
generators i.e. a generator with the draw off upon the bottom. Figure 1 is a vertical
section and Figure 2 a horizontal section on the line a band Figure 4 a horizontal
section on the line ed or a generator with the draw off in the bottom. Figure 3 is
a vertical section and Figure 5 a horizontal section on the line e.f. Figure 6
represents a modification.
The furnace A formed of firebricks or equivalent is surrounded by an envelope of
sheet metal B. The top thereof is provided with a feed hopper C, closed by a bell and
a slide J and a series of openings all round it to afford means of ascertaining the
descent of the charges. The interior of the shaft is cylindrical in its lower part as far
as the blast pipes and tapers towards the top in different degress of conicality. The
opening T allows the raking of the charge and the door D the cleaning of the
bottom.
Each series of the tuyeres d d d' d' and dd strongly inclined upwards open into a
common box or casing K and carry at their orifices sliding iron doors ¹ which are
controlled through corresponding openings in the air chamber or casing K which are
closed by similar doors glazed with blue glass. The casing K communicates with
the blast by the passage W into which steam is injected through the pipe R provided.
with a stop valve h.
The axes of the tuyeres d d d" are tangential to a cylinder y having the same axis
as the furnace. The outlet ports S through which the gas escapes are formed in the
walls of a channel L constructed of fire brick or the like upon the bottom of the
furnace ; this channel communicates with the channel 1 of sheet metal furnished with
a refractory lining see Figures 1, 2 and 4.
In certain cases the generator is placed on a receptacle such as either a furnace for
the reduction of ores or a steel iron or glass smelting furnace a welding or a puddling
furnace in order to form a hydrogen furnace. In such cases the outlet ports S for
the draw off are formed in the fire brick lining of the hearth and bottom of the
furnace the latter forming the top of the receptacle V of the hydrogen furnace. Each
of the outlet ports S corresponds with an opening in the fire brick lining provided
with a glass which permits the attendant to examine the state of the outlet port

page_text: Figures 3 and 5. In Figure 6 the outlet ports S are represented covered by a double
door D. The conduit L may also open into this receptacle V and be provided with a
valve P and a damper P¹ to regulate the current of the gas produced.
The cinders are liquified by the addition of flux and are withdrawn through the
opening O of the channel or are carried away by the gas currents produced in the
receptacle V.
Having now particularly described and ascertained the nature of the said invention
as communicated to me by my foreign correspondent and in what manner the same is
to be performed I declare that what I claim is :-
1. In a cupola serving as a superheated hydrogen gas generator the construction of
the draw off below the blast this draw off consisting of a series of openings in the
walls of a channel constructed upon the bottom or in the lining and bottom of the
generator substantially as specified.
2. The arrangement of several series of tuyeres one above the other for the
purpose of introducing the blast at different heights at will either successively or
simultaneously.
3. The arrangement of the generator or the receptacle such as V to supply the said
receptacle with gas the bottom of the generator forming both the outlet for the gas
and the top of the receptacle of the hydrogen furnace substantially as specified.