Improved Process of and Apparatus for the Generation of Water Gas from Coke, Coal, or other Fuel
Year: 1895

page_text: Date of Application, 18th Feb., 1895
Complete Specification Left, 13th Nov., 1895-Accepted 15th Feb., 1896
PROVISIONAL SPECIFICATION.
Improved Process of and Apparatus for the Generation of Water
Gas from Coke, Coal, or other Fuel
I, DR. HUGO STRACHE, Heuberggasse 9, Vienna in the Empire of Austria,
Tutor, do hereby declare the nature of my said invention to be as follows:-
The processes hitherto employed for generating water gas may be resorted to
only when coke is selected as fuel. With such processes generator gas forms
during the passing of the hot blast into the coke and takes up part of the heat of
the fuel, while only a small proportion of such generator gas is converted into
water gas. In order to utilize the heat stored up in the generator-gas, regenerators
have been employed, in which refractory stone is heated by the generator-gas
burnt by means of a secondary current of air, the steam, during the gasifying thus
being heated, before reaching the coke, by the refractory stone. No very favorable
results, however, have been attained by such procedure, chiefly owing to the
imperfect construction of the regenerators.
The object of this invention is to remove all these defects, to render it possible
to use, besides coke, also coal or other fuel and to fully utilize the heat of
combustion.
I render it possible to employ other fuels besides coke (for instance, coal) by
coking the fuel by means of super-heated steam and allowing the resulting gas (in
most cases illuminating gas) as well as the tar-vapors to pass through a highly
heated column of coke, the hydrocarbon being thereby decomposed into carbon
and hydrogen (sometimes a little carburetted hydrogen or marsh-gas).
The resulting and separated carbon is deposited partly on the coke while part
remains as soot in suspension in the gas; this may be subsequently removed by
washing the gas with water. The super-heated steam which has already served
for coking the fuel, passes simultaneously with the illuminating gas and the tar-
vapor through the glowing coke and thus generates water gas which passes out of
the apparatus together with the hydrogen resulting from the decomposition of the
hydro-carbon. The cokes thus obtained then pass directly into the room destined
for effecting the decomposition of the illuminating gas tar and steam by means of
glowing coke.
The great utilization of the heat of combustion is effected:
1) by the improved construction of regenerators employed and
2) by combining such regenerators with recuperators i.e. the apparatus for
continuously heating the air of combustion during the passing in of the
warm blast.
The
My apparatus for carrying out this improved process consists essentially of a
generator, to which the fuel is fed through a gas-tight funnel.
The generator
comprises an upper and lower part and a slag-chamber. The fresh fuel passing
through said upper part of the generator reaches the lower part in the form of
coke. A hot-blast now passes into the slag chamber, heats the coke.
generator-gas thereby resulting escapes through an opening before reaching said
upper part of the generator, a valve being provided by means of which the
regenerator may be made to communicate either with the upper or lower part of
the generator. The generator-gas thus first reaches the flame chamber of the
regenerator, where it is burnt by an upper hot-blast issuing from a canal in the

page_text: regenerator. The products of combustion then pass through the charge of
the regenerator, whose superficial area is made as large as possible by means
of ribs. The product of combustion, whilst still hot, pass from the lower end of
the regenerator into the recuperator, which latter preferably surrounds the
generator in order to avoid loss of heat by radiation. The canal in the recuperator
preferably ascends in spiral form round the regenerator and the escaping gases,
very much cooled, pass through a suitable outlet or valve. The wind entering at
the top of the recuperator canal goes in the opposite direction of the products of
combustion and is thus highly heated and fed to the generator from below as
bottom wind and from above as top wind to the regenerator, suitable valves or
slides being provided to regulate the wind. When the generator and regenerator
have reached the required temperature, gas-tight slides are regulated in such
manner that the wind supply of the apparatus is cut off as well as the outlet of the
spent gases, whereas the water gas to be generated may escape through one of the
slides or valves. At the same time the generator and regenerator are brought into
communication with each other.
Steam is now passed through an ejector which draws in the gases present in the
generator and the mixture of steam and gas is thus passed into the regenerator
where it is heated to a high degree. It now finds its way to the apper part of the
generator containing the fresh fuel. This fuel is coked by the superheated gas and
at the same time water gas is generated from the resulting illuminating gas and tar
and from the coke by means of the steam in the lower part of the generator; this
water gas then passes out of the apparatus.
It will be evident that steam alone may be blown into the regenerator i.e. without
being intermixed with gas, the ejector being thus dispensed with; the transmission
of heat from the regenerator to the fresh fuel in that case, however, is not so
perfect.
The advantages of my improved apparatus for generating water gas as compared
with those hitherto employed are:
1) The applicability of large coal or other coking fuel ;
2) Considerably increased output of gas seeing that the heat of the spent gases
is utilized in the generator again.
3) Considerably higher efficiency of the apparatus of the same size on account
of its being heated by the hot blast quicker than when a cold blast is used.
4) More complete decomposition of the steam on account of the higher
temperature in the generator.
Dated this 18th day of February 1895
Improved Process of and Apparatus for the Generation of Water
Gas from Coke, Coal, or other Fuel.
I, DR. HUGO STRACHE, of Heubergasse 2, Vienna, in the Empire of Austria,
Tutor, do hereby declare the nature of my said invention and in what manner the
game is to be performed, to be particularly described and ascertained in and by
the following statement :-
The processes hitherto employed for generating water-gas are only practicable
when coke is used as the fuel. With such processes generator-gas forms during
the admitting of the hot-blast into the coke and absorbs part of the heat of the
fuel, while but a small proportion (35%) of such generator gas is converted into
In order to utilize the heat thus stored up in the generator-gas,
water-gas.

page_text: regenerators have been employed, in which refractory stone is heated by the
generator-gas burnt by means of a secondary current of air, on which heated
stone the admitted steam impinges during the gasifying and is thus superheated
before reaching the coke. No very favorable results, however, have been
attained by such procedure, chiefly owing to the imperfect construction of said
regenerators.
The object of this invention is to remove all these defects, to render it possible
to use not only coke, but also coal or other fuel and to fully utilize the heat of
combustion.
I render it possible to employ fuels, other than coke, (for instance, coal) by
coking the fuel by means of a super-heated steam and allowing the resulting gas
(illuminating gas) as well as the tar-vapors to pass through a highly-heated column
of coke, the hydrocarbon being thereby decomposed into carbon and hydrogen
(sometimes a little carburetted hydrogen or marsh-gas is present).
The resulting separated carbon deposits itself partly on the coke, while part
remains as soot in suspension in the gas; the latter may be subsequently removed
by washing the gas with water. The super-heated steam which has already served
for coking the fuel, passes simultaneously with the illuminating-gas, and the tar-
vapors through the glowing coke, and thus generates water-gas which escapes from
the apparatus together with the hydrogen resulting from the decomposition of the
hydro-carbon. Such coke then passes directly into the chamber destined for
effecting the decomposition of the illuminating-gas, tar and steam.
The great utilization of the heat of combustion is effected :-
1) by the improved construction of regenerator employed, and
2) by combining such regenerator with a recuperator, i.e., the apparatus for
continuously heating the air of combustion during the admission of the
warm-blast.
These improvements in the regenerator have resulted from careful observation,
which showed that during the short period of gasifying-about five minutes-
necessary for generating the water gas, the ordinary brick or stone linings of the
regenerator cannot by any means give off in so short time all the heat stored up in
same. This was proved by the fact that the surfaces of the bricks cooled until
quite dark by the steam passed over same, recommenced to glow in a short time
owing to the heat stored up in same gradually making its way to the surface.
Seeing that the heat given off is not dependent upon the amount of stonework but
rather upon the superficial area of same, the efficiency of the regenerator may thus
be considerably increased by enlarging the superficial area of such stones, i.e., by
providing same with ribs or the like.
Regenerators in themselves, however, can only be used to advantage when great
differences of temperature are to be contended with. If, for instance, it were
desired to cool the gases of combustion but a few hundred degrees by means of
regenerators, the latter would necessarily have to be of exceedingly large and
cumbrous dimensions. Recuperators having metallic heating surfaces, on the
contrary, are very well adapted for low temperatures, whereas they are not at all
suitable for high temperatures owing to their low resisting power. For this
reason the recuperator in the present instance is arranged outside of or around
the regenerator to allow of the fuel being fully utilized in case the gases of
combustion be very much cooled (i.e. when the air of combustion is highly
heated) and this without having any evil effect on the apparatus. The functions
of the two apparatus are thus divided in such manner that the regenerator
effects the super-heating of the steam, while the recuperator heats the air of
combustion.
A simple calculation of the transmission of heat shows that the recuperators
previously employed must be of abnormally-large dimensions to produce corre-
spondingly-good results. As regards the attaining of better results with smaller
apparatus, there remains to be considered that the efficiency of a recuperator is
dependent firstly upon the counter-current principle being exactly carried out, and

page_text: secondly upon the superficial area of the material employed for absorbing and giving
off heat.
The counter-current principle can be properly carried out by passing the gases
of combustion through a passage built of bricks or other bad-conducting material,
in the centre of which passage the air moves in the reverse direction in an iron
pipe the passage may be straight, angular, spiral or zig-zag in form. Seeing
that the efficiency of said smaller apparatuses is substantially dependent upon the
superficial area of the materials through which the heat must penetrate, such
superficial area should be increased to the greatest extent possible; this is
best effected by providing the material with both inwardly and outwardly-
directed ribs.
I will now describe my invention by way of example with reference to the
accompanying drawing, in which Fig. 1 represents the apparatus in section, and
Fig. 2 is an enlarged section of valve hereinafter referred to.
G1, G2, G3 is the generator, the fuel (for instance coal) being fed to same
through the tightly-closing funnel T. As will be hereinafter described, the fuel
is coked in the upper part G 3 and reaches the part G 2 in the form of coke. The
hot-blast is admitted into the slag-chamber G¹ and heats the coke. The generator-
gas (Siemens' gas) resulting therefrom escapes through the opening o¹ before
reaching the upper part G 3 of the generator, a regulator valve v being
also provided by means of which the regenerator R, R, R may be brought
into communication either with the lower part of the generator through the
opening o¹, or with the upper part G 3 through the opening o 2. The generator-
gas thus first reaches the flame chamber of the regenerator where it is burnt by a
hot blast ascending through the passage K, K. The gases of combustion then
impinge against the lining of the regenerator, the superficial area of which lining,
as already mentioned, is made as large as possible by means of ribs. The products
of combustion while still hot (about 1000° C.) pass from the lower part of the
regenerator into the recuperator which latter preferably surrounds the regenerator,
in order to avoid loss of heat by radiation. As shown in the drawing, the recuperator
passage ascends in spiral form round the regenerator and the gases thus escape
through the valve S 3 very much cooled.
The air admitted enters at the top of the recuperator-passage into the inner
chamber J formed by ribbed, cast-steel bodies and thus takes the opposite course
to that of the gases of combustion, and after being highly heated, enters at the
lower part of the generator, as bottom air, and at the upper part through the
passage K, K into the regenerator as top air; suitable slides or valves L³, L2
are provided for regulating the strength of the blast. On the generator and
regenerator attaining the required temperature, the gas-tight valves S¹, S2, S3
are regulated in such manner that the blast is cut off and the spent-gases
prevented from escaping at $ 3, whereas the water-gas to be generated may escape
through the valve S¹. At the same time, the valve V is put into such a position,
that the generator and regenerator communicate with each other through o².
T
5
Steam is now injected at D into the ejector E arranged outside the generator,
such steam thus drawing in with it a small portion of the gases present in the
generator. This mixture of steam and gas thus passes into the regenerator at B,
from whence it issues very much heated and passes over the open valve V
through o² to the fresh fuel in the upper part G³ of the generator. This fuel is
coked by the superheated gases, while water-gas is at the same time generated
from the illuminating gas and tar formed, and from the coke, by means of the
steam in the lower part of the generator; the greater part of such water-gas then
escapes from the apparatus through valves S₁, while a small portion circulates
together with the steam through the regenerator and generator. During this
period the passage leading to the latter is in communication with the outlet whereas
when the hot blast is being admitted into the apparatus such passage is brought 5
into communication with the air passage leading to the recuperator by means of
a valve or slide such as is shown at S¹, Fig. 2. It will be evident that steam alone

page_text: may be blown into the regenerator, i.e., without being intermixed with gas, the
ejector being thus dispensed with; the transmission of heat from the regenerator to
the fresh fuel in that case however is not so perfect.
The advantages of my improved apparatus for generating water-gas as compared
with those hitherto employed are:-
1. That fat coal or other coking-fuel may be used.
2. That the yield of gas is considerably higher, seeing that the heat of the
spent-gases is returned to the generator.
3. That the efficiency of the apparatus is considerably higher than other
apparatuses of the same dimensions, on account of the hot-blast heating more
quickly than a cold blast.
4. That the steam is more completely decomposed by reason of the higher
temperature in the generator.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1) A process of generating water gas from coke, coal or other fuel consisting in
heating the air of combustion during the period of admitting the hot-blast by means
of the hot combustible gases rising from the regenerator (R) and with the aid of
the recuperator (J) and in super-heating the steam in the regenerator (R) during
the gasifying period, such stean thus effecting the coking of the fuel, while the
resulting illuminating-gases and tar mixed with the steam are converted into
water-gas in a highly heated coking chamber, substantially as described and shown
in the drawing.
2) In an apparatus for carrying out the process of generating water-gas as set
forth in Claim 1) the arrangement of a recuperator (J) the surfaces of which on
both sides of the walls are enlarged or increased by ribs or the like for more
speedily absorbing and giving off the heat, substantially as described and shown in
the drawing.
3) In an apparatus for carrying out the process of generating water gas as set
forth in Claim 1) the arrangement of lining bricks inside the regenerator (R)
the superficial area of which bricks is increased by ribs, substantially as and for the
purpose described.
Dated this 12th day of November 1905
J. C. CHAPMAN, C.P.A.,
70 Chancery Lane, London, W.C., Patent Agent.