IMPROVEMENTS IN FURNACES FOR THE MANUFACTURE OF ILLUMINATING GAS, PARTLY AP- PLICABLE TO FURNACES FOR HEATING PURPOSES GENERALLY
Year: 1877

page_text: LETTERS PATENT to Gerard Wenzeslaus von Nawrocki, of the Firm of J. Brandt
and G. W. von Nawrocki, Civil Engineers and Patent Agents, of No. 2, Koch
Strasse, Berlin, in the German Empire, for the Invention of "IMPROVEMENTS
IN FURNACES FOR THE MANUFACTURE OF ILLUMINATING GAS, PARTLY AP-
PLICABLE TO FURNACES FOR HEATING PURPOSES GENERALLY." A communication
by Georg August Friedrich Liegel, of Stralsund, in the German Empire.
Sealed the 11th December 1877, and dated the 19th June 1877.
PROVISIONAL SPECIFICATION left by the said Gerard Wenzeslaus von
Nawrocki at the Office of the Commissioners of Patents on the 19th June
1877.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W. von
Nawrocki, Civil Engineers and Patent Agents, of No. 2, Koch Strasse, Berlin, in
the German Empire. "IMPROVEMENTS IN FURNACES FOR THE MANUFACTURE OF
ILLUMINATING ĜAS, PARTLY APPLICABLE TO FURNACES FOR HEATING PURPOSES
GENERALLY." [A communication by Georg August Friedrich Liegel, of Stralsund,
in the German Empire.]
According to the present Invention furnaces for the manufacture of illuminating
gas are constructed as follows:-Centrally beneath the chamber retort is a com-
bustion chamber, which widens out laterally from a comparatively narrow longi-
tudinal opening in the floor of the retort chamber to near the bottom of the
combustion chamber, from which point the sides rapidly approach each other to the
bottom of the chamber, in which is a very narrow longitudinal slit. The back or
inner end of the combustion chamber slopes forward from the top to the bottom, so
that the combustion chamber is of considerably less length at the bottom than at
the top. The said sloping sides and back end of the chamber are formed stepped
instead of with plane surfaces, in order to prevent the air and gases from creeping
up between the mass of fuel in the chamber and the said sides, instead of per-
meating through the fuel. The front end of the combustion chamber is provided
just outside the retort chamber with a feeding hole, through which the fuel is
introduced, and which is closed hermetically by a cover with hydraulic joint.

page_text: Through the narrow slit at the bottom of the combustion chamber is admitted a
comparatively small quantity of air, sufficient for producing carbonic oxide gas by
imperfect combustion of the fuel. The requisite air for the perfect combustion of
the carbonic oxide is introduced into the space in the chamber above the mass of
fuel through side flues, which communicate with the outer air through openings at
the front end provided with regulating valves, and after being led backwards and
forwards in the brickwork of the chainber so as to take up a portion of the radiated
heat, enter the combustion chamber through openings at the front end. A short
distance below the narrow slit at the bottom of the combustion chamber is placed a
grate, on each side of which narrow longitudinal passages are formed in the brick-
work, rising from points level with the grate and converging towards the said
narrow slit in the chamber, so that the air entering the latter is first caused to pass
up through the said inclined passages. By this arrangement the small coal, ashes,
and slag that fall through the slit in the chamber are received-upon the grate below,
on which by this means a small secondary fire is maintained, the heat of which is
usefully employed, firstly, to heat the air passing in through the side passages; and,
secondly, to maintain the slag in a liquid state as it passes through the slit of the
chamber, in which it would otherwise solidify, so as to choke the air passage. The
lateral air currents being conducted directly against the edges of the slit, cool these
sufficiently to prevent them from melting. The buruing gases pass froin the
combustion chamber through the longitudinal opening at top into the retort
chamber.
In order to protect the retort or retorts that are situated immediately over this
longitudinal opening from the more direct contact with. the flames, they are
carried on inassive cast-iron bearers supported at intervals on transverse brick
arches, and so formed on the under side as to cause the flames to diverge to either
side of the retort.
Instead of constructing the gas retorts of such a length is to enter the brickwork
of the chamber only to the extent required for supporting them, I make them long
enough to extend to within the thickness of one brick of the outer face of the brick
work, by which means a considerable increase in the heating surface of the retort is
obtained.
The before-described construction of combustion chamber with air flues. and
passages and lower grate, is also applicable for other heating purposes, such as for
heating steam boilers, tar stills, and the like.
1

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gerard Wenzeslaus von Nawrocki in the Great Seal Patent Office on
the 11th December 1877.
.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W. von
Nawrocki, Civil Engineers and Patent - Agents, of No. 2, Koch Strasse, Berlin, in
the German Empire. "IMPROVEMENTS IN FURNACES FOR THE MANUFACTURE OF
ILLUMINATING ĜAS, PARTLY. APPLICABLE TO FURNACES FOR HEATING PURPOSES
GENERALLY." A communication by Georg August Friedrich Liegel, of Stralsund
in the German Empire.
According to the present Invention furnaces for the manufacture of illuminating
gas are constructed as follows:-Centrally, beneath the retort chamber is a com-
bustion chamber, which widens out laterally from a comparatively narrow longi:
tudinal opening, in the floor of the retort chamber to near the bottom of the
combustion chamber, from which point the sides rapidly approach each other to the
bottom of the chamber, in which is a very narrow longitudinal slit. The back or
inner end of the combustion chamber slopes forward from the top to the bottom, so
that the combustion chamber is of considerable less length at the bottom than at
the top. The said sloping sides and back end of the chamber are formed stepped
instead of with plane surfaces, in order to prevent the air and gases from creeping.
up between the mass fuel in the chamber and the said sides, instead of per-
meating through the fuel. The front end of the combustion chamber is provided
just outside the retort chamber with a feeding hole, through which the fuel is
introduced, and which is closed hermetically by a cover with a hydraulic joint.
Through the narrow slit at the bottom of the combustion chamber is admitted a
comparatively small quantity of air, sufficient for producing carbonic oxide gas by.
imperfect combustion of the fuel. The requisite air for the perfect combustion of
the carbonic oxide is introduced into the space in the chamber above the mass of
fuel through side flues, which communicate with the outer air through openings at
the front end provided with regulating valves, and after being led backwards and
forwards in the brickwork of the chamber, so as to take up a portion of the radiated
heat, enter the combustion chamber through openings at the front end. A short
distance below the narrow slit at the bottom of the combustion chamber is placed a
grate, on each side of which narrow longitudinal passages are formed in the brick-
work, rising from points level with the grate and converging towards the said
narrow slit in the chamber, so that the air entering the latter is first caused to pass
up through the said inclined passages. By this arrangement the small coal, ushes,
and slag that fall through the slit in the chamber are received upon the grate below,
on which by this means a small secondary fire is maintained, the heat of which is
usefully employed, firstly, to heat the air passing in through the side passages;
and, secondly, to maintain the slag in a liquid state as it passes through the slit of
the chamber, in which it would otherwise solidify so as to choke the air passage.
The lateral air currents being conducted directly against the edges of the slit cool
these sufficiently to prevent them from melting. The burning gases pass from
the combustion chamber through the longitudinal opening at top into the retort
chamber.
In order to protect the retort or retorts that are situated immediately over this
longitudinal opening from the inore direct contact with the flames they are carried
on massive cast-iron bearers supported at intervals on transverse brick arches, and
so formed on the under side as to cause the flames to diverge to either side of the
retort.
Instead of constructing the gas retorts of such a length as to enter the brickwork
of the chamber only to the extent required for supporting them, I make them long.
enough to extend to within the thickness of one brick of the outer face of the
brickwork, by which means a considerable increase in the heating surface of the
retort is obtained.

page_text: passages and lower grate, is also applicable for other heating purposes, such as for
heating steam boilers, tar stills, and the like.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents a longitudinal section through the middle of a furnace according
to this Invention for the manufacture of gas; Fig. 3 is a transverse section on the
line A, B, of Fig. 1; and Fig. 4, a sectional plan on the line C, D. The two latter
Figures are drawn to an enlarged scale.
The furnace shewn in these Figures is arranged to take eight retorts, but it is to
be understood that a similar construction is applicable to different numbers of retorts,
as, for example, to nine, ten, or eleven, as shewn by the sections Figs. 5, 6, and 7,
respectively.
In the furnace shewn in Figs. 1 to 4 the 8 retorts are arranged in three tiers, the
lowest of the middle tier being omitted, and each of them extends the whole
length of the furnace, through the front thereof, and backwards within a brick
length of the facing of the back wall. Under the retorts is situated the com-
bustion chamber a, b, the lower part of which a receives the supply of coke, and
may be termed the generator, and in the upper part b, which may be called the
regenerator, the carbonic oxide produced below is by the farther combustion con-
verted into carbonic anhydride. The sides of the combustion chamber are stepped
gradually outwards to an increasing width for about three-fourths of the depth, and
for the remaining fourth they narrow in to a long narrow slit c along the bottom,
through which enters sufficient air for the partial combustion of the coke producing
carbonic oxide. The completion of the combustion is effected by the admission of
a farther supply of air, which enters by the apertures d governed by doors g, passes
along the channels e, and issues into the front part of the combustion chamber by
the mouths. The products of combustion leave the furnace at the back part, and
are carried off by the flue h. The fuel is fed by the opening i, which is covered by
a water jointed cap. The fragments of coke or the slag or ashes that fall through
the slit creach the fire-grate k, where the fortner are consumed, and whence the
latter drop into the ash-pit l. On each side of the grate is a cheek m separated
from the rest of the building by a narrow passage n, admitting a sinall quantity of
air to pass through the slit c. The lowest of the middle retorts rets on a bed o
supported on the arches p.
When tar is employed for heating the arrangement is modified, as shewn in
Fig. 8, which represents a longitudinal section of the furnace; Fig. 9, which is a
section on A, B, of Fig. 8; Fig. 10, a sectional plan on C, D; and Fig. 11, a section
on F, F.
A tank a of wood or metal (shewn in plan at Fig. 9a), supported on a framing b,
contains the tar, which is warmed by a steam pipe c: In one corner, separated by a
screen d, is a small steam coil e, having numerous convolutions for more highly
heating the tar. A siphon pipe f, provided with a cock g, lets the tar flow into a
funnel h, from which a pipe i conducts it to the furnace. The pipe i has a cap k
lipped down to prevent entrance of any foreign matter, such as might obstruct the
pipe. The tar flows from the pipe i through a hole e into the combustion chamber m
and strikes the floor n, on which is formed a mass of tar coke, which is from time
to time raked forward on to the floor o. The air for combustion enters by a long
narrow slit in the door p, and passing over the tar coke on o partly consumes it,
and in a highly heated condition enters the combustion chamber m, where it meets
the descending tar partly vaporised by the heat radiated from the walls, and mixing t
with the vapour effects its complete combustion, so that no smoke is produced. The
supply of air is regulated by a scrow sluice valve q.
Fig. 12 represents a longitudinal section; Fig. 13, a transverse section; and
Fig. 14, a sectional plan of a modified form of a furnace applied to heat a boiler,
which in this case is of the double tube kind. The combustion chamber is made 5

page_text: without any outward swell, and the fuel is fed from the front. In other respects
in construction and action it resembles the coke furnace first described.
Having thus described the nature of this Invention and in what manner the
same is to be performed, as communicated to me by my correspondent, I claim,—
First. Constructing a furnace with a deep fuel chamber tapered at the bottom to
a narrow slit for the supply of air to generate combustible gas from the fuel, and
with flues arranged for heating air supplied above the fuel for the complete com-
bustion of the said gas, substantially as herein described.
Second. In a furnace of the kind above referred to, stepping the interior faces of
the walls, so that the air being impeded in its passage along these walls has to pass
through the body of the fuel, substantially as herein described.
Third. In a furnace of the kind above referred to, providing a small fire-grate
under the slit and small channels directing air towards the edges of the slit, sub-
stantially as and for the purposes herein set forth.
Fourth. In a furnace of the kind above referred to, when applied in the manu-
facture of gas, supporting and shielding the retort or retorts next the combustion
chamber by means of a bed resting on arches, and shaped so as to direct the
products of combustion towards the other retorts, substantially as herein described.
In witness whereof, I, the said Gerard Wenzeslaus von Nawrocki, have here-
unto set my hand and seal, this Seventh day of December, in the year of
our Lord One thousand eight hundred and seventy-seven.
GERARD WENZESLAUS V NAWROCKI
(7.01