Improved Method of Manufacturing Producer and Water Gas.
Year: 1891

page_text: Date of Application, 28th Nov., 1891
Complete Specification Left, 27th Aug., 1892-Accepted, 1st Oct., 1892
PROVISIONAL SPECIFICATION.
Improved Method of Manufacturing Producer and Water Gas.
I, ASMUS JABS of Wyhlen, Baden, Germany, Manager of Works do hereby
declare the nature of this invention to be as follows:
-
When fuel is converted into carbonic oxide, that is to say, in manufacturing
producer and water gas, it is well known that the carbon of the fuel, when first
brought in contact with the air supply does not combine with the oxygen to form
carbonic oxide, but carbonic acid, and that the latter is reduced to carbonic oxide
by subsequent contact with the upper incandescent layers of fuel. In every gas
producer therefore there are to be found three different zones, namely a lower
oxidizing or combustion zone, in which carbonic acid gas containing air, nitrogen
and a small percentage of carbonic oxide, is formed, a middle reduction zone above
this in which the carbonic acid is reduced, and an upper preliminary heating zone,
in which the fuel introduced from above is heated and deprived of its volatile
constituents by the escaping gases rising up from below.
With such an arrangement of the working of the gas producer, practice has
shewn that it is unavoidable that a portion of the carbonic acid gas first formed
passes away without being reduced, and passes off together with the carbonic oxide,
which fact greatly diminishes the heating powers of the producer and water gas.
The cause of this imperfect reduction of the carbonic acid formed in the lowest
zone is that the extent of the reducing zone is comparatively small, and consequently
a certain proportion of the carbonic acid has not sufficient time to come in contact
with the carbonaceous material that should effect its reduction.
It has however not been possible to give to the reducing zone the required
extension, because the reduction of the carbonic acid involves a very considerable
absorption of heat (about 69000 calories), so that only those layers of fuel can be
maintained at a sufficiently high temperature for effecting reduction, which are
immediately above the oxidizing zone, and which are maintained at incandescence
temperature by conduction and radiation of heat from the freshly produced highly
heated carbonic acid. With increasing distance from the ozidizing zone the
temperature sinks very rapidly in the reducing zone, owing to the rapidly
decreasing action of the heat radiation and conduction, and the heat absorption
caused by the reduction, so that with most constructions of producers the reducing
action ceases at a height of a few decimeters above the combustion zone, and the
preliminary heating zone there commences.
The present invention has for its object to diminish this defect, and consists in
mixing with the fucl that is supplied to the producer, incombustible materials such
as fire clay, lumps of porcelain, burnt clay &c. The fuel will then become
consumed by degrees as it descends, so that in the lower part of the producer only
the added refractory material will exist, which will have been highly heated in the
combustion zone above, and will transfer this heat to the incoming air supply.
By this means a moving store of heat is as it were created, consisting of lumps
of fireclay porcelain or other refractory material which is fed together with the
fuel into the top of the furnace, and sinks down according as the fuel burns away
or is gasified, and is withdrawn at the bottom together with the ashes, in order to
be again introduced at the top, where it takes up the heat from the escaping gases,
and again gives off heat to the incoming air or gases as it sinks to the bottom.
Thus an excellent utilisation of the heat is brought about.
The proportion of fuel in the charge consequently gradually decreases in the
direction from top to bottom, and in consequence of the large proportion of
refractory material will be a considerable extension of the oxidizing and, in

page_text: particular, of the reducing zone, so that the carbonic acid formed in the lower part
of the producer has ample time to become reduced to carbonic oxide, by coming
into intimate contact with the upper layers of highly heated fuel.
Of great importance is the fact that in the mixing of the fuel with the refractory
material in the above described manner, the working of the apparatus is altered
from that of the producers working in the ordinary manner, in so far that, in the
new arrangement the action in the reducing zone does not solely consist of the
reduction of the carbonic acid produced below, out also simultaneously of an
oxidation of fuel by means of the air contained in the gases, which has not entered
into combustion in the lower zone.
As the fuel becomes gradually consumed as it descends, as above stated, so that
finally only the refractory material remains, the entering air or gas supply first only
meets with layers which contain no fuel, and then passes into the combustion zone,
the lower part of which contains only very little fuel, so that only a portion of the
oxygen contained in the air supply can be used for producing carbonic acid while
the other portion rises up into the upper layers. Thus there will be in the upper part
of the combustion zone and in the lower and middle portion of the reducing zone a
gaseous mixture which does not mostly consist of carbonic oxide and nitrogen, as is
ordinarily the case, but which also still contains a large proportion of free oxygen.
This gaseous mixture consequently operates upon the fuel in the reducing zone in
two different ways; firstly, the carbonic acid is reduced to carbonic oxide by
combining with the fuel under considerable absorption of heat, and secondly a
proportion of the fuel which is considerable relatively to the quantity of carbonic
acid reduced, enters into combination with the oxygen of the air supply under
production of considerable heat, so that the heat absorbed by the reduction process
is made good again by the simultaneous heat production of the oxidising process.
In proportion as the gases containing carbonic acid and oxygen rising from the
combustion zone ascend higher and higher through the upper layers of the
producer, and are rendered gradually richer in carbonic oxide by the simultaneous
reaction of the carbon upon the carbonic acid and the oxygen, the temperature of
such upper layers will gradually decrease, as in consequence of the decrease of
oxygen, the combustion process will cease, and consequently there will occur in the
upper zone only a preliminary heating of the freshly introduced charges fuel and
refractory material, and the consequent disengagement of the volatile constituents
of the former.
t
By the above described means the first mentioned disadvantage of the imperfect
reduction of the carbonic acid, owing to the limited extent of the reducing zone,
will be avoided as by the mixing with the fuel of refractory materials in the
described manner and by the oxidizing which takes place as above described
in the reducing zone, the latter will become considerably extended, so that the
carbonic acid rising up out of the combustion zone, as also the uncombined oxygen of
the air or gas supply, will have ample time to be converted entirely into carbonic
oxide by reaction with the fuel.
The distilling off of the volatile constituents in the upper zone may of course be
facilitated by the introduction of a greater or less quantity of steam, according to
the nature of the fuel employed.
On the accompanying drawings is shewn by way of example a vertical section of
a construction of gas producer suitable for carrying out the above described process.
A Fig. is the shaft of the producer, of ordinary construction, supported by
suitable bearers, which shaft is charged at top with the mixture of fuel and fireclay,
while the air supply and steam are admitted in regulated quantities through the
supply pipes a and b.
The cooled ashes and fireclay, porcelain, &c., are removed at bottom through the
opening while the gaseous mixture produced is led off through a pipe d into a gas
holder or directly to the place of consumption.
In Figs. 2 and 2 are shewn diagrammatically the old method of working and
the above described improved method side by side in order to shew the difference

page_text: by comparison. Fig. 2 shews the charge of fuel and the extent of the oxidizing,
reducing, and preliminary heating zone of the old method, while Fig. 24 shews the
extent of the similar zones of the new method of working and the proportion of
fuel and refractory material existing in each of the zones. As shewn in Fig. 2, the
preliminary heating and gasifying zone of the old method occupies the greatest
space, while with the new method at Fig. 2, the oxidizing and reducing zones
occupy the greatest space.
Dated this 28th day of November 1891.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Method of Manufacturing Producer and Water Gas.
1, ASMUS JABS, of Wyhlen, Baden, Germany, Manager of Works, 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 :-
When fuel is converted into carbonic oxide, that is to say, in manufacturing
producer and water gas, it is well known that the carbon of the fuel, when first
brought in contact with the air supply does not combine with the oxygen to form
carbonic oxide, but carbonic acid, and that the latter is reduced to carbonic oxide
by subsequent contact with the upper incandescent layers of fuel.
In every gas
producer therefore there are to be found three different zones, namely a lower
oxidizing or combustion zone, in which carbonic acid gas containing air, nitrogen
and a small percentage of carbonic oxide is formed, a middle reduction zone above
this in which the carbonic acid is reduced, and an upper preliminary heating zone,
in which the fuel introduced from above is heated and deprived of its volatile
constituents by the escaping gases rising up from below.
With such an arrangement of the working of the gas producer, practice has
shewn that it is unavoidable that a portion of the carbonic acid gas first formed
passes away without being reduced, and passes off together with the carbonic oxide,
which fact greatly diminishes the heating powers of the producer gas.
The cause of this imperfect reduction of the carbonic acid forined in the lowest
zone is that the extent of the reducing zone is comparatively small, and consequently
a certain proportion of the carbonic acid has not sufficient time to come in contact
with the carbonaceous material that should effect its reduction.
It has however not been possible to give to the reducing zone the required
extension, because the reduction of the carbonic acid involves a very considerable
absorption of heat (about 69000 calories) so that only those layers of fuel can be
maintained at a sufficiently high temperature for effecting reduction, which are
immediately above the oxidizing zone, and which are maintained at incandescence
temperature by conduction and radiation of heat from the freshly produced highly
heated carbonic acid. With increasing distance from the oxidizing zone the
temperature sinks very rapidly in the reducing zone, owing to the rapidly decreasing
action of the heat radiation and conduction, and the heat absorption caused by the
reduction, so that with most constructions of producers the reducing action ceases
at a height of a few decimeters above the combustion zone, and the preliminary
heating zone there commences.
The present invention has for its object to diminish this defect, and consists in
mixing with the fuel that is supplied to the producer, incombustible materials such
as fireclay, lumps of porcelain, burnt clay &c. The fuel will then become consumed
by degrees as it descends, so that in the lower part of the producer only the added
refractory material will exist, which will have been highly heated in the combustion
zone above, and will transfer this heat to the incoming air supply..
By this means a moving store of heat is as it were created, cousisting of lumps of

page_text: fireclay porcelain or other refractory material which is fed together with the fuel
into the top of the furnace, and sinks down according as the fuel burns away or is
gasified, and is withdrawn at the bottom together with the ashes, in order to be
again introduced at the top, where it takes up the heat from the escaping gases,
and again gives off heat to the incoming air or gases as it sinks to the bottom.
Thus an excellent utilisation of the heat is brought about.
The proportion of fuel in the charge consequently gradually decreases in the
direction from top to bottom, and in consequence of the large proportion of
refractory material will be a considerable extension of the oxidizing and, in
particular, of the reducing zone, so that the carbonic acid formed in the lower part
of the producer has ample time to become reduced to carbonic oxide, by coming
into intimate contact with the upper layers of highly heated fuel.
Of great importance is the fact that in the mixing of the fuel with the refractory
material in the above described manner, the working of the apparatus is altered
from that of the producers working in the ordinary manner, in so far that, in the new
arrangement the action in the reducing zone does not solely consist of the reduction
of the carbonic acid produced below, but also simultaneously of an oxidation of fuel
by means of the air contained in the gases, which has not entered into combustion
in the lower zone.
As the fuel becomes gradually consumed as it descends, as above stated, so that
finally only the refractory material remains, the entering air supply first only meets
with layers which contain no fuel, and then passes into the combustion zone, the
lower part of which contains only very little fuel, so that only a portion of the
oxygen contained in the air supply can be used for producing carbonic acid while
the other portion rises up into the upper layers.
Thus there will be in the upper part of the combustion zone and in the lower and
middle portion of the reducing zone a gaseous mixture which does not mostly consist
of carbonic oxide and nitrogen, as is ordinarily the case, but which also still contains
a large proportion of free oxygen..
This gaseous mixture consequently operates upon the fuel in the. reducing zone in
two different ways; firstly, the carbonic acid is reduced to carbonic oxide by
combining with the fuel under considerable absorption of heat, and secondly a
proportion of the fuel which is considerable relatively to the quantity of carbonic
acid reduced, enters into combination with the oxygen of the air supply under
production of considerable heat, so that the heat absorbed by the reduction
process is made good again by the simultaneous heat production of the oxidising
process.
•
In proportion as the gases containing carbonic acid and oxygen rising from the
combustion zone ascend higher and higher through the upper layers of the producer
and are rendered gradually richer in carbonic oxide by the simultaneous reaction
of the carbon upon the carbonic acid and the oxygen, the temperature of such
upper layers will gradually decrease, as in consequence of the decrease of oxygen,
the combustion process will cease, and consequently there will occur in the upper
zone only a preliminary heating of the freshly introduced charges fuel and
refractory material, and the consequent disengagement of the volatile constituents
of the former.
By the above described means the first mentioned disadvantage of the imperfect
reduction of the carbonic acid, owing to the limited extent of the reducing zone,
will be avoided as by the mixing with the fuel of refractory materials in the
described manner and by the oxidizing process which takes place as above described
in the reducing zone, the latter will become considerably extended, so that the
carbonic acid rising up out of the combustion zone, as also the uncombined oxygen
of the air supply, will have ample time to be converted entirely into carbonic oxide
by reaction with the fuel.
The distilling off of the volatile constituents in the upper zone may of course be
facilitated by the introduction of a greater or less quantity of steam, according to
the nature of the fuel employed.

page_text: On the drawings accompanying my Provisional Specification is shewn by way of
example a vertical section of a construction of gas producer suitable for carrying
out the above described process.
A Fig. is the shaft of the producer, of ordinary construction, supported by
suitable bearers, which shaft is charged at top with the mixture of fuel and fire
clay, while the air supply and steam are admitted in regulated quantities through
the supply pipes a and .
The cooled ashes and fire clay porcelain &c. are removed at bottom through the
opening c while the gaseous mixture produced is led off through a pipe d into a gas
holder or directly to the place of consumption.
In Figs. 2 and 24 are shewn diagrammatically the old method of working and
the above described improved method side by side in order to shew the difference
by comparison. Fig. 2 shews the charge of fuel and the extent of the oxidizing,
reducing, and preliminary heating zone of the old method, while Fig. 2 shews the
extent of the similar zones of the new method of working and the proportion of
fuel and refractory material existing in each of the zones. As shewn in Fig. 2
the preliminary heating and gasifying zone of the old method occupies the greatest
space, while with the new method at Fig. 24, the oxidizing and reducing zones
occupy the greatest space.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
A method of generating producer gas wherein the solid fuel which is to be
converted into gas is mixed with incombustible or refractory material so that on
feeding such mixture into the upper end of a gas producer, the incombustible
material has the effect of producing such an extension of the reducing zone as to
secure the complete reduction of the carbonic acid generated in the combustion
zone, substantially as described.
Dated this 27th day of August 1892.
ABEL & IMRAY,
Agents for the Applicant.