Improvements in Obtaining Combustible Gases, Ammonia, and Tar from Fuel, and in Apparatus therefor.
Year: 1893

page_text: Date of Application, 24th June, 1893
Complete Specification Left, 24th Mar., 1894-Accepted, 9th June, 1894
Improvements in Obtaining Combustible Gases, Ammonia, and Tar
from Fuel, and in Apparatus therefor.
I, LUDWIG MOND of 20 Avenue Road, Regent's Park, London, in the County
of Middlesex, Chemist, do hereby declare the nature of this invention to be as
follows:
:-
In a previous Patent numbered and dated 3923 of 1883 I have described a
process for obtaining combustible gases, ammonia and tar from coal, etc., by burning
the coal in a gas producer, by means of a mixture of air and steam, and condensing
the ammonia and tar from the resulting gases; and in a subsequent Patent
numbered and dated 8973 of 1885 I have set forth how a suitable mixture of air
and steam for this purpose can be obtained economically by the utilization of the
heat stored up in the gases issuing from the producer. I have now found that the
yield of ammonia can be considerably increased by raising this mixture of air and
steam to a temperature of not less than 150° C. before it enters the producer.
In order to effect this rise of temperature without the expense of extra fuel I
surround the producer in which the fuel is burnt, with a box or mantle, thus
forming a hollow space around it. I also take the hot gases made in the producer
through long pipes, preferably arranged in zig-zag, which I surround by wider
pipes, thus forming an annular space or spaces, and I pass the mixture of air and
steam on its way to the producer through this annular space or spaces in a
direction contrary to the current of the gas, and subsequently I pass it through
the hollow space formed round the gas producer, and take it from thence into the
bottom of the producer.
The gases leaving the producer are cooled in their passage through the long
pipes, but they still retain heat enough to serve for the purpose of the production
of such a mixture of air and steam, as set forth in my before-mentioned
Specification numbered and dated 8973 of 1885.
I prefer to make the gas producer of circular section and to construct it of a
wrought iron casing lined inside with a thin lining of fire-bricks, and of a second
wrought iron casing surrounding the first one, the outside of which is covered by
a non-conducting material. An annular space is thus formed between the two
wrought iron casings all round the producers, through which the mixture of air
and steam passes downward on its way to the grate at the bottom of the producer,
and becomes heated to the desired temperature. I insert a cast-iron cylinder or a
truncated cone into the top of this gas producer, which reaches some distance down
inside the inner casing and into which I charge the fresh fuel from time to time,
and I keep this cylinder or truncated cone at all times partially filled with coal,
whereby avoid coal-dust getting into the long gas-pipes, and also gasify the
volatile products of the fuel more perfectly.
In order to facilitate the removal of the cinders from the bottom of the gas
producer, I provide it with a circular grate constructed of wedge-shaped bars,
much wider at one end than the other, and fixed with the wider end on the top,
and with an open space between each bar, so as to form a grate in the form of an
inverted truncated cone with a circular opening in the middle, through which the
מ.

page_text: cinders can freely fall into the space below this grate. The outer wrought iron
casing I draw together towards the lower end of the producer, so as to form an
inverted truncated cone nearly parallel to the grate, and the base of this cone I lute
by a water lute, through which the ashes and cinders can be removed without opening
the bottom of the producer.
Dated this 23rd day of June 1893.
W. P. THOMPSON & BOULT,
Of London, Nottingham, Liverpool, and Manchester,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Obtaining Combustible Gases, Ammonia, and Tar
from Fuel, and in Apparatus therefor.
I, LUDWIG MOND of 20 Avenue Road, Regent's Park, London in the County of
Middlesex, Chemist do hereby declare the nature of this invention and in what
manner the same 19 to be performed, to be particularly described and ascertained
in and by the following statement:-
The invention is best described by the aid of the annexed drawings-
Figure 1 is a ground plan;
Figure 2 a vertical section through the line TX ;
Figure 3 a vertical section through the line U V, showing also the front view of
the gas producer;
Figure 4, enlarged ground plan, and
Figure 5, enlarged front view of the circular grate of the gas producer.
Like letters relate to like parts in all these figures.
A, is the body or chamber of the gas producer, surrounded by bb brick lining,
cc inner iron casing, d d outer iron casing, ee is a hollow iron platform to which
both these casings are rivetted and which allows unequal expansion of the two
casings to take place without damaging the structure.
fis the top of the gas producer consisting of a single iron cover fastened and
made tight to the inside shell and lined with brick-work.
99 is a bell-shaped casting which is always kept partly filled with fuel and
which is charged by means of a feed hopper into which the fuel is delivered from
the reservoir k.
j is a conical grate; is the water-lute and m m the feet carrying the whole
structure.
ppp are the pipes or conduits for the producer gas, surrounded by 99, pipes of
larger diameter, thus forming an annular space s s through which the mixture of
air and steam is forced into the apparatus by a suitable fan or blower, entering
through the pipe and passing round the pipes »pp and subsequently through
the annular space between the two iron shells c and d in the direction of the arrows
until it arrives at the grate j, taking up heat all the way and thus arriving at the
desired temperature.
The gas issuing from the producer carries with it some dust which is apt to
settle in the pipes ppp and requires removing from time to time.
These
pipes ppp are therefore arranged vertically in zig-zag form with short horizontal
branches between them, and are provided with blank flanches y y at their bottom
to make them accessible for cleaning and with a small opening (closed by a plug
or cock) in these flanches through which the dust can from time to time be blown
out without interfering with the work of the producer.
=
To avoid loss of heat, the pipes 9 q, as well as the outer shell d d of the producer
are covered with a non-conducting composition.

page_text: The inner shell of the producer ends in the casting n which carries the wedge
shaped fire-bars (iii) of the conical grate ; which are supported by a ring o o.
This apparatus is especially well adapted for burning very poor qualities of fine
fuel, even those of coking character. The clinkers have no tendency to stick to
the sides of the producer and even a coking fuel descends very regularly and easily,
requiring no assistance by poking with bars from the top. The conical grate
leads to a very regular admission of the mixture of air and stean through all
the sections of the fuel in the producer, thus avoiding partial overheating and
the consequent destruction of ammonia, which it is the object of the invention to
recover. The removal of the clinkers which fall through the opening in the
centre of the grate into the water-lute is easily effected without in any way
interrupting the continuous work of the producer, although the mixture of air and
steam is generally forced into the producer under a pressure of six to nine inches
of water in order to overcome the resistance of the fine fuel and to burn a quantity
of fuel in the apparatus adequate to its size and cost.
The interstices between the bars of the grate are subject to be blocked from
time to time by agglutinated fine dust, which is easily removed by knocking about
the bars which are made movable for this purpose, and which are readily accessible
through doors to provided in the lower part of the outer shell a short distance
above where it dips into the water-lute.
I do not confine myself to the minor details of the apparatus and the specific
materials mentioned as used in its construction.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I wish it to be understood
that I am aware that circular gas producers with an annular space round them for
the purpose of heating the air entering the producer have been described long ago,
and also that several devices have been described for heating this air by means of
the waste heat of the gas producers; but none of these are sufficient to attain the
rise of temperature required for my purpose.
I am also aware that it has been proposed to use a mixture of superheated steam
with cold air for obtaining ammonia from fuel burnt in gas producers, but this
becomes impracticable if the mixture of air and steam is to be obtained economically,
as, for instance, by the method I have described in my Patent No. 8973 of 1885,
while, if the steam required has all to be raised in steam boilers and to be
superheated sufficiently to attain the object of this present invention, a greater
expenditure would have to be incurred for extra fuel than would be compensated
for by the increase in the ammonia obtained.
I believe that I have been the first to discover that, by burning fuel with a
mixture of air and steam in proper proportions raised to a temperature of not less
than 150° C., the quantity of ammonia obtained from the fuel is largely increased,
and that I have been the first to design apparatus by which such a mixture of air
and steam can be economically raised to this temperature by the waste heat of the
gas producer without the expenditure of extra fuel, and I therefore declare that
what I claim is-
1. The improvement in obtaining combustible gases, ammonia and tar from fuel,.
which consists in burning the fuel in a gas producer by means of a mixture of air
and steam heated to a temperature of not less than 150° C., whereby the amount of
ammonia is considerably increased.
2. The improvement in apparatus for obtaining combustible gases, ammonia and
tar from fuel, which consists in a superheater constructed of a series of pipes
arranged vertically in zig-zag form, through which the hot gases from the producer
pass and which are surrounded by wider pipes, thus forming an annular space
through which the mixture of air and steam is driven in a direction opposite to the
producer gas and the combination of this superheater with a gas producer, substan-
tially as described.

page_text: 3. The manufacture and use of the various improvements in apparatus for
obtaining combustible gases, ammonia and tar from fuel, substantially as herein-
before set forth and dscribed.
Dated this 22nd day of March 1894.
W. P. THOMPSON & BOULT,
Of London, Liverpool, Manchester, and Nottingham,
Agents for the Applicant.