IMPROVEMENTS IN THE PRODUCTION OF COMBUSTIBLE GAS, AND IN APPARATUS THErefor, which LATTER ARE ALSO APPLICABLE FOR CALCINING AND CARBONIZING OPERATIONS."
Year: 1881

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton
Buildings, Chancery Lane, in the County of Middlesex, for an Invention
of IMPROVEMENTS IN THE PRODUCTION OF COMBUSTIBLE GAS, AND IN
APPARATUS THErefor, which LATTER ARE ALSO APPLICABLE FOR CALCINING
AND CARBONIZING OPERATIONS." A communication from abroad by Eugen
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 2nd May 1881.
20
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. IMPROVEMENTS IN THE PRODUCTION OF COMBUSTIBLE
CAS, AND IN APPARATUS THEREFOR, WHICH LATTER ARE ALSO APPLICABLE FOR
CALCINING AND CARBONIZING OPERATIONS." [A communication from abroad by
Eugen Langen, of Cologne, in the German Empire.]
This Invention has reference to the production of combustible gas in that
description of gas producers in which the coal or carbonaceous material is caused
to descend continuously in a vertical or inclined shaft or retort, at the lower end of
which imperfect combustion of the material with air is caused to take place,
producing carbonic oxide and nitrogen, while the heat evolved is caused to distill
off the volatile constituents of the carbonaceous material in the upper part of the
shaft, the different kinds of gases so generated being led off either separately from
or together with each other.
The presence of the large proportion of nitrogen in the said gases produced by
imperfect combustion of the fuel, is in many cases a source of great inconvenience
in the application of these gases for industrial purposes, and one part of the present
Invention has for its object to effect the production of combustible gases in gas
producers of the kind above referred to in such a manner that from a given
quantity of carbonaceous material there shall be generated the maximum quantity
of combustible gas, more or less entirely free from nitrogen. For this purpose the
before mentioned carbonic oxide and nitrogen gases produced at the lower part of
Diss 11

page_text: the shaft or retort are entirely or in great part conducted out of the same into a
separate chamber or flue, where the carbonic oxide is caused to enter into com-
bustion with heated air, the heat so produced being employed to assist in the
conversion of steam or other suitable fluid into combustible gases that take the
place of the carbonic oxide withdrawn from the producer.
By preference the combustion of the said gas is caused to take place in an
annular chamber surrounding the shaft or retort in which the carbonaceous matter
descends, into which annular chamber air previously heated to a high degree by
the gaseous products of such combustion is conducted, so as by the combustion to
heat the carbonaceous contents of the retort to a very high degree, and con-
sequently to distil from the same a maximum quantity of volatile constituents at
a point some distance above that where the carbonic oxide and nitrogen are
withdrawn, the steam or other fluid being introduced into such highly heated
portion of the carbonaceous matter, in contact with which it becomes decomposed
producing in the case of steam pure carbonic oxide and hydrogen and compounds
of the latter with carbon, which in ascending mix together with the other car-
bonaceous gases distilled off from the fuel in the upper part of the retort, and pass
away with them to wherevor required. If these gases are to be employed for
heating purposes only, then steam alone may be employed, as described, but if they
are to be used for illuminating purposes, then some hydrocarbon fluid, such as
petroleum, may be introduced together with the steam to add to the illuminating
power of the gases produced.
Various arrangements of gas producers may be employed for carrying out the
above described method of operating, the arrangement employed by preference is
as follows-A vertical or it may be somewhat inclined shaft has in its lowest part
a fire chamber, the lower end of which may either be entirely closed by a grate, or
it may be partly open, so as to allow a portion of the coke to descend past the
grate into a water tank placed to receive the coke and cinders, which are from time
to time removed from the tank. In the middle of the fire chamber is an air pipe
with lateral openings protected by a conical hood. Above the fire chamber is a
retort chamber having around it an annular combustion space supplied with the
gases produced in the fire chamber below and with air heated by a regenerator,
the said gas and air being introduced through passages opening at some height
above the bottom of the combustion chamber. Above the retort chamber is a
feeding chamber which is also surrounded by an annular space communicating by
openings at its bottom with the retort chamber, and communicating at its top with
a pipe leading to an exhauster. The three chambers, the feeding chamber, the
retort chamber, and the fire chamber, communicate freely with one another. From
the lowest part of the combustion space surrounding the retort chamber a lateral
passage leads to a chimney, and this passage forming the regenerator is divided by
a sloping partition made of plates corrugated or ribbed so as to present extended
surface, so that while hot products of combustion pass from the combustion
chamber to the chimney through a passage below the plates, air passes in the
opposite direction through a passage above the plates, and becomes highly heated
on its way to the combustion space surrounding the retort. The latter passage is
made comparatively narrow, so as to bring the air into intimate contact with the
plates, but the part of the passage into which the products of combustion first
enter is formed comparatively large, so as not to bring too great a heat to bear
upon the metal plates in the first instance. The producer is worked in the
following manner-The fire and retort chambers being charged with coke kindled
at the bottom of the former, the wall of the retort chamber becomes heated to
redness, and thereupon the feeding chamber is supplied with coal. As the coke
consumes or as coke or cinder is withdrawn from below the fire chamber, the
contents of the producer descend and fresh coal is supplied at the top. The coal
in descending through the retort chamber gives off its gas, which is withdrawn
through the annular space surrounding the feeding chamber by the exhauster. If
the gas is to be used for heating, a portion of the gas produced in the fire chamber

page_text: may be permitted to mingle with it; but if, as before stated, the presence of the
nitrogen would be objectionable, or if illuminating gas is desired to be produced.
the draught of the exhauster and that of the chimney are so balanced that only the
rich gas is withdrawn by the exhauster, the whole of the lower gases being drawn
off into the annular combustion chamber.
For introducing steam into the retort chamber, a water tank is fixed outside the
apparatus with a sloping pipe leading upwards from its bottom into the retort
chamber. By adjusting the overflow of the tank to various levels, the height of
the water in the sloping pipe, which passes through the hot wall of the apparatus,
may be varied so as to regulate the supply of steam to the exact amount required.
In like manner a regulated supply of hydrocarbon vapour may also be introduced
into the retort when a richer gas is required.
It will readily be understood that the above described apparatus can also be
employed for calcining ore and other minerals or for carbonizing substances, for
which purpose it would be merely necessary to mix the necessary proportion of
carbonaceous matter with the substances to be operated upon when charging them
into the upper end of the retort.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the
2nd November 1881.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN THE PRODUCTION OF COMBUSTIBLE
GAS, AND IN APPARATUS THEREFOR, WHICH LATTER ARE ALSO APPLICABLE FOR
CALCINING AND CARBONIZING OPERATIONS." A communication from abroad by
Eugen Langen, of Cologne, in the German Empire.
This Invention has reference to the production of combustible gas in that
description of gas producers, in which the coal or carbonaceous material is caused
to descend continuously in a vertical or inclined shaft or retort, at the lower end
of which imperfect combustion of the material with air is caused to take place,
producing carbonic oxide and nitrogen, while the heat evolved is caused to distil
off the volatile constituents of the carbonaceous material in the upper part of the
shaft, the different kind of gases so generated being led off either separately from
or together with each other.
The presence of the large proportion of nitrogen in the said gases produced by
the imperfect combustion of the fuel is in many cases a source of great inconvenience
in the application of these gases for industrial purposes, and one part of the
present Invention has for its object to effect the production of combustible gases
in gas producers of the kind above referred to in such a manner that from a given,
quantity of carbonaceous material there shall be generated the maximum quantity
of combustible gas more or less free from nitrogen. For this purpose the before
mentioned carbonic oxide and nitrogen gases produced at the lower part of the
shaft or retort are entirely or in great part conducted out of the same into a
separate chamber or flue where the carbonic oxide is caused to enter into com-
bustion with heated air, the heat so produced being employed to assist in the
, conversion of steam or other suitable fluid into combustible gases that take the
place of the carbonic oxide withdrawn from the producer.
By preference the combustion of the said gas is caused to take place in an annular
chamber surrounding the shaft or retort in which the carbonaceous matter descends,
into which annular chamber air previously heated to a high degree by the gaseous
products of such combustion is conducted, so as by the combustion to heat the
carbonaceous contents of the retorts to a very high degree, and consequently to distil
from the same a maximum quantity of volatile constituents at a point some distance
above that where the carbonic oxide and nitrogen are withdrawn, the steam or other
fluid being introduced into such highly heated portion of the carbonaceous matter
in contact with which it becomes decomposed, producing in the case of steam pure
carbonic oxide and hydrogen, and compounds of the latter with carbon, which in
ascending mix together with the other carbonaceous gases distilled off from the
fuel in the upper part of the retort and pass away with them to wherever required.
If these gases are to be employed for heating purposes only, then steam alone may
be employed as described; but if they are to be used for illuminating purposes,
then some-hydrocarbon fluid such as petroleum may be introduced together with
the steam to add to the illuminating power of the gases produced.
Various arrangements of gas producers may be employed for carrying out the
above described method of operating. Fig. 1 of the accompanying Drawing shews
a vertical section, and Fig. 2 shews a sectional plan on line X, X, of one arrange-
ment. The upper part of the apparatus consists of the space A into which the
carbonaceous material is charged surrounded by an annular space B, into which
the gases produced by distillation escapes through holes O in the lower part of A,

page_text: the parts A and B being conveniently made of metal in one casting. From the
space B the gases are conducted away to wherever required by the pipe B¹. Below
the space A is the shaft or retort C, which is heated externally to a high degree
and in which the distillation of the volatile constituents from the carbonaceous
material is consequently carried on as this gradually descends towards the lower
chamber where the conversion of the non-volatile constituents into combustible gas
is effected by their imperfect combustion with air admitted below. This generating
chamber consists of a cast iron casing lined with refractory material, its lower end
dipping into water contained in a tank E, and having at its middle a firegrate F
supplied with air by the pipe F¹. This grate may either be so constructed as to
prevent the descent of any carbonaceous matter past it, so that the whole of the
fuel is converted into combustible gas, in which case the water tank E would be
dispensed with or when it is not desired to convert the whole of the material
into gas the grate may be formed as shewn on the Drawing, so as to allow a certain
portion of the carbonaceous material to descend past it into the tank E¹, whence
it is withdrawn from time to time.
From the top of the chamber D the combustible gases generated therein, being
carbonic acid and nitrogen are led by flues G into an annular combustion
chamber H surrounding the retort C, while at the same time highly heated air
passes into the said chamber by flues I. The flues G and I are led up some height
in the chamber H, as shewn, so as by the combustion of the gas and air to produce
an intense heat in the upper part of the retort C and its contents, thereby distilling
off from the carbonaceous material the maximum quantity of volatile constituents
as it descends and before it reaches the upper end of the chamber D.
The lower part of the annular combustion chamber H is formed narrower, and
from its lowest and coolest point the hot gaseous products of combustion arc led
by flues K into the regenerator L, where they are caused before escaping to the
chimney M to impart a greater part of their heat to the incoming air on its way
to the combustion chamber. The regenerator consists of a chamber divided by a
sloping partition N formed of metal plates into two passages of which L¹, through
which the air passes, is formed of small depth so as to bring the air into intimate
contact with the partition N, while the passage L2 into which the hot products of
combustion pass is formed of considerable capacity where the products enter, and
gradually narrows towards the exit end. By this arrangement the gaseous
products are prevented on entering from heating the metal plates N to too high a
degree, such as would rapidly destroy them, as is frequently the case with the
ordinary construction of regenerators with metallic partitions, while as the products
pass towards the narrower end of the passage, after having given off a large portion
of their heat and become contracted in volume, they are brought into more
intimate contact with the partition. The plates forming this partition are con-
structed with ribs on both sides, as shewn more clearly in the enlarged cross-
section thereof at Fig. 3, so as to offer very extended surfaces for taking up the
heat from the products and imparting them to the air. Any accumulation of solid
deposits in the passage L² may be readily removed from time to time through the
door L³, as shewn.
Above the chamber D of the producer, steam or other suitable fluid is led into
the retort C through one or more pipes Q, in order as before stated by its decom-
position in contact with the highly heated carbonaceous matter, to form pure
carbonic oxide and hydrogen, which mix and pass off with the gases distilled off
above. This steam or other fluid is supplied in regulated quantity by the following
arrangement. Outside the producer is a tank P supplied with the water or other
liquid employed, and having several overflow cocks Pi at different levels, so that by
opening any one of these cocks, the water can be maintained at a corresponding
level in the tank. The pipe Q leads from the bottom of the tank in a slanting
direction upwards through the heated walls of the producer to a level somewhat
above the highest level at which water can stand in the tank. Thus, according to
the level at which the water is maintained in the tank, a greater or less volume

page_text: thereof will be subjected inside the pipe to the heat of the producer, wherebyla
greater or less quantity of steam will be generated and introduced into the retort:
The waste water from the overflow of the tank maybe led byla pipe Peither into
a water space in the bottom of the chamber D as shewn, or into the tank E, or
elsewhere. As before stated, if it be desired to. produce a gas of high illuminating
power, then some hydrocarbon vapour may be introduced into the retort in a
similar manner to that above described.
The operation of the producer is as follows:-Assuming the chamber D to have
been filled with burning fuel, and that the walls of the retort C have become heated
sufficiently by the combustion in the chamber H, the retort is filled up to the
apertures O leading into the annular channel B with coke, and above that with
coal. As the fuel becomes consumed in the chamber D, the contents of the retort
sink (their descent may be accelerated by the removal of coke from the tank E if
desired) the coal in the upper part of the retort descends into the highly heated
compartment C, and the gas production begins, the distilled gases passing through
the apertures O into the annular space B, whence they are withdrawn by an
exhauster through the pipe B together with the other gases produced by the
decomposition of the steam below. Meanwhile fresh coal is fed at the top. The
exhauster action and the chimney draught are so adjusted to balance each other
that none of the distilled gas finds its way to the chimney, and none or only a
limited quantity of the products of imperfect combustion in the chamber D mingle
with the gas distilled above. For producing gas for heating purposes, the whole of
the carbonaceous matter should be utilised, and in that case such portions of the gas
produced in the chamber D as are not required for heating the distillation space
may be drawn off by the exhauster along with the gas distilled off if the presence
of a certain proportion of nitrogen is not objectionable for the purpose to which the
gases are applied. But when the gases are used for illuminating purposes, the whole
of the said products should be drawn off either to be wholly burnt in the chamber H
or to be partly led away to be used for other purposes.
It will be evident that the above described construction of gas producer may
also be applied to the calcining of ores and other minerals, or for carbonising
substances, for which purposes it would only be necessary to mix the necessary
proportion of carbonaceous matter with the substances to be operated upon when
charging them into the upper end of the retort. In this case the whole of the
carbonaceous gases evolved may be caused to pass through the flues G into the
chamber H to be there burnt, instead of being partly led off through the openings O
above.
Having thus described the nature of this Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondent, I
wish it to be understood that I do not limit myself to the precise construction of
apparatus herein described with reference to the accompanying Drawings, as this
may be variously modified for carrying out the before described Invention, nor do
I claim generally the drawing off of a portion of the gases from a gas producer into
a chamber surrounding the same where it is made to enter into combustion with
heated air, as I am aware that this has already been proposed, but I claim,---
First. In gas producers, the method of producing combustible gas more or less
free from nitrogen, by causing a portion or the whole of the carbonic oxide with
nitrogen generated by imperfect combustion of the fuel with air above the firegrate
-to pass into a separate combustion chamber, whereby its combustion with a further
supply of highly heated air, heat is produced for effecting the decomposition of
steam or other suitable fluids into combustible gases that are added to the other
gases in the producer to take the place of those withdrawn, substantially as herein
described.
Second. The construction of apparatus for the manufacture of gas with vertical
or inclined shaft or retort, in which a maximum quantity of combustible gas as free
as possible from nitrogen is produced by withdrawing through side channels in the
lower part of the retort, the carbonic oxide and nitrogen resulting from the com-

page_text: bustion at such lower part, and causing the same to enter into combustion with
highly heated air in a combustion chamber surrounding the upper part of the retort,
in order by the heat generated to distil off a maximum quantity of the volatile
constituents of the fuel, and to produce combustible gases by decomposing steam or
other suitable fluid introduced into the retort at a point above the said exit passages,
for the carbonic oxide, substantially as herein described.
Third. Causing the hot gases from the lower part of the retort and the atmospheric
air to enter the annular chamber surrounding the retort at some height from the
lower end thereof, so as by their combustion to apply the more intense heat to the
upper part of the retort, while the gaseous products of such combustion are conducted
away from the lower cooler part of the combustion chamber through a regenerator
where they are made to impart heat to the incoming air for supporting the said
combustion, substantially as herein described.
Fourth. In regenerators consisting of a passage or chamber in which the hot gaseous
products of combustion from the furnace are made to give up their heat by contact
with one side of a cast iron partition, with the other side of which the air for com-
bustion of the furnace is brought into contact, the method of constructing the said
chamber for the gaseous products of such large capacity, and of making the cast
iron partition of such extended surface, that the highly heated gases owing to their
expansion on entering, and to the large surface of metal with which they are brought
into contact, will not heat the latter beyond a red heat.
Fifth. The construction of regenerators for imparting the heat from the products
of combustion to the incoming air; consisting of the chamber divided by a metallic
partition N into a narrow compartment L' through which the air passes, and a com-
paratively large compartment L2 through which the products of combustion pass,
the said metallic partition consisting of plates having ribs or projections on both
sides, offering very extended surfaces both for taking up heat from the products of
combustion, and for imparting such heat to the air, substantially as described.
Sixth. The method of regulating the supply of steam or other fluid to the fuel in
the retort by varying the level of water or other liquid in an external vessel,
communicating at bottom with a pipe leading into the retort at a height above that
of the said vessel, in which pipe the water or other liquid is evaporated by the heat
of the retort, substantially as described.
Seventh. The combination of the feeding chamber A with annular space B for
leading off the products of distillation shaft, or retort C heated by gaseous com-
bustion in the annular chamber H, chamber D, flues G, I, K, regenerator L, and
pipe or pipes Q, for the introduction of steam or other fluid, all arranged and
operating as herein set forth.
Eighth. The use of apparatus for introducing the regulated supply of steam or
other fluid into a gas producer, the said apparatus consisting of tank P with over-
flow cocks P¹ at different levels, in combination with one or more pipes Q, leading
from the bottom of the tank upwards, through the producers to a height at or
above the highest water level of the tank, substantially as described.
Ninth. The use of apparatus constructed and operating as herein described, for
carbonizing, regenerating, reducing, and calcining substances, substantially as set
forth.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
CHAS. D. ABEL. (L.S.)