Improvements in Furnaces.
Year: 1895

page_text: PROVISIONAL DIUINICATION.
Improvements in Furnaces.
1. JOHN GJERS, of Ayresome Iron Works, Middlesboro' on Tees, in the County
of York, Ironmaster, do hereby declare the nature of this invention to be as
follows:-
In the Specification of a former Patent, No. 2720 of 1894, I have described
furnaces in which the fuel is contained in a close combustion chamber having a
solid bottom, and is supplied with hot air, for surface combustion, through an air
inlet or passage that is in communication with an air heater and is so arranged
that the hot air is caused to impinge on the surface of the fuel, the resulting flame
and hot gases then passing into a melting or heating chamber, and I have also
described the construction of such furnaces in conjunction with regenerators, and in
another application for Patent, bearing even date herewith, No. 10823 I am
describing improvements in and appertaining to apparatus for generating steam.
Now my present invention has reference to the construction, for various purposes,
of a furnace in which the fuel is contained in a close combustion chamber having
a fire grate, below which is a closed ash pit provided with a water bottom, or with
a steam supply, or it may be with both, in suchwise that water vapor ascending
within the closed ash pit will not only serve to prevent excessive heating of the
fire bars, but, passing between them and through the mass of ignited fuel on the
fire grate, will be decomposed, thus affording additional combustible gases.
The close combustion chamber is supplied with hot air for surface combustion
through an air inlet or passage that is in communication with an air heater, and is
so arranged that the hot air is caused to impinge upon the surface of the fuel, the
resulting flame and hot gases then passing into a heating chamber or into a flue or
flues or otherwise according to the class of furnace to which my invention is
applied. The construction and arrangement of the furnace will obviously be
subject to modification according to the purpose for which it is to be adapted.
My invention may readily be applied in connection with furnaces constructed in
other respects as described in the Specification of my said former Patent of 1894,
or to other furnaces, variously arranged, and provided with heaters or recuperators
or regenerators of any suitable construction, or it may be used in accordance
with the invention forming the subject of my other application of even date
already referred to.
In some cases I combine with my improved fire place a continuous recuperator
constructed with a number of narrow zig-zag flues separated from a number of
zig-zag air passages by thin firebrick walls that serve to absorb heat from the hot
gases flowing through the flues and transmit it to the air flowing through the
passages, the whole being walled round so as to form a tower the lower portion of
which contains the combustion chamber, above it being a smoke chamber, and then
the recuperator with chimney.
I however, sometimes combine other forms of recuperators with my improved
fireplace as above set forth.
When using a water bottom I may provide for automatic supply of water so as
to maintain a practically constant level.
When using regenerators in carrying out my invention I prefer not to

page_text: employ a water bottom but to provide for admission of steam from an independent
source to the ash pit and for cutting off the supply of such steam when reversing.
Dated this 31st day of May 1895.
W. LLOYD WISE,
Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
Improvements in Furnaces.
I, JOHN GJERS, of Ayresome Iron Works, Middlesboro-on-Tees, in the County
of York, Ironmaster, 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 :--
In the Specification of a former Patent, No. 2720 of 1894, I have described
furnaces in which the fuel is contained in a close combustion chamber having a
solid bottom, and is supplied with hot air, for surface combustion, through an
air inlet or passage that is in communication with an air heater and is so
arranged that the hot air is caused to impinge on the surface of the fuel, the
sulting flame and hot gases then passing into a melting or heating chamber, and
ve also described the construction of such furnaces in conjunction with
regene tors, and in another application for Patent, bearing even date herewith,
No. 10823 I am describing improvements in and appertaining to apparatus for
generating steam.
Now my present invention has reference to the construction, for various
purposes, of a furnace in which the fuel is contained in a close combustion
chamber having a fire grate, below which is a closed ash pit provided with a
water bottom, or with a steam supply, or it may be with both, in such wise
that water vapor ascending within the closed ash pit will not only serve to
prevent excessive heating of the fire bars, but, passing between them and through
the mass of ignited fuel on the fire grate, will be decomposed, thus affording
additional combustible gases. The close combustion chamber is supplied with
hot air for surface combustion through an air inlet or passage that is in
communication with an air heater, and is so arranged that the hot air is caused to
impinge upon the surface of the fuel, the resulting flame and hot gases then
passing into a heating chamber or into a flue or flues or otherwise according to the
class of furnace to which my invention is applied. The construction and arrange-
ment of the furnace will obviously be subject to modification according to the
purpose for which it is to be adapted.?
My invention may readily be applied in connection with furnaces constructed
in other respects as described in the Specification of my said former Patent of 1894,
or to other furnaces, variously arranged, and provided with heaters or recuperators
or regenerators of any suitable construction, or it may be used in accordance with
the invention forming the subject of my other application of even date already.
referred to.
.
In some cases I combine with my improved fire place a continuous recuperator
constructed with a number of narrow zig-zag flues separated from a number of
zig-zag air passages by thin fire brick walls that serve to absorb heat from the
hot gases flowing through the flues and transmit it to the air flowing through the
passages, the whole being walled round so as to form a tower the lower portion of
which contains the combustion chamber, above it being a smoke chamber, and then
the recuperator with chimney.
1, however, sometimes combine other forms of recuperators with my improved
fireplace as above set forth.

page_text: When using a water bottom I may provide for automatic supply of water so as
to maintain a practically constant level.
When using regenerators in carrying out my invention I prefer not to employ
a water bottom but to provide for admission of steam from an independent source
to the ash pit and for cutting off the supply of such steam when reversing.
Fig. 1 of the accompanying illustrative drawings shews the application of my
present invention to a furnace of the kind represented in Figs. 1 to 3 inclusive of
the drawings annexed to the Specification of my Patent No. 2720 of 1894, 1 being
the combustion chamber, 2 the fire door, 3 the ash pit, 4 its air tight door, 5 a pipe
for carrying live_steam_into_the_closed_ash_pit below the firegrate 6, 7 a poking
hole, 8 the port leading from the combustion chamber to the melting or heating
chamber, and 9 the fire brick flue leading to the central flue of the regenerator 10.
Fig. 2 is a vertical section on the line A B of Fig. 3; Fig. 3 is a sectional
plan, and Fig. 4 is a vertical section on the line C D of Fig. 2 illustrating my
present invention as applied in a steam generating apparatus according to
Figs. 4, 5 and 6 of the drawings annexed to the Complete Specification of my
application for Patent No. 10823 of 1895. The combustion chamber 1 is arranged
opposite the front end of the lower boiler shell 1ª and is provided with ordinary
firebars 6 below which is an ash pit 3. This ash pit has a water-bottom 4° and is
normally closed against access of air by a hinged flap valve 4d the lower end of
which dips into the water constituting the water-bottom and is thus sealed. The
water is gradually converted into steam which serves to prevent overheating of
the fire-grate, and, by decomposition, as it passes through the bed of ignited fuel,
to produce an additional quantity of combustible gases, as in the arrangement
herein before described with reference to and shown in Fig. 1, fresh water being
supplied from time to time (it may be by an automatic feed) to compensate for
that evaporated. The flame and hot gases pass through the fire tubes 1 in the
lower shell 1ª into flue 11 thence through the fire tubes of the upper shell 1' into
the smoke box or chamber 11* from which the hot gases pass into the various
gas flues 11 in the recuperator, through which they flow in a zig-zag course and
finally pass off at the top of the chimney 12. In their course through the
flues 11 the hot gases give up part of their heat to the thin brick walls 11*
which conduct it to the air flowing through the adjoining narrow air passages 11°
on either side, the air thus heated after following the zig-zag course of the air
passages finally emerging into the combustion chamber 1 in thin streams that
impinge upon the fuel and thus cause efficient combustion thereof.
Fig. 5 illustrates partly in side elevation and partly in vertical section the
application of my present invention to a reheating furnace such as is used in steel
and iron works, the waste heat, after passing through the furnace, being returned
through a boiler, placed over the furnace, to a recuperator built over the fire-
grate, where part of the remaining heat of the waste gases is used for heating the
air for combustion ;
Fig. 6 shows a vertical section in a plane at right angles to Fig. 5 ;
Fig. 7 is a view showing the apparatus in horizontal section, partly in the
plane of the axes of the boiler flues and partly in a parallel plane higher up;
Fig. 8 shows a transverse section.
In this case, as in the other examples illustrated, the firegrate is arranged
for the surface combustion of solid fuel with heated air according to the
Specification of my Patent No. 2720 of 1894, the necessary air being introduced
from above the top of the fuel bed at a point most suitable for combustion,
and the fuel resting in accordance with my present invention upon fire bars 6
some little distance below the bottoms of which there is a water trough 4.
4d is a hinged flap valve which hangs down from the girder that carries the
front ends of the fire bars, and dips into the water, forming a water seal and
thus preventing the entrance of air below the fire bars, the other sides of the
ash pit being closed in by the brick walls.

page_text: One or more firing doors 2 is or are provided for introducing fuel on to the
fire bars in suitable positions, such door or doors being made to fit closely so as
to prevent access of air.
The air for combustion having been previously heated enters the combustion
chamber 1 from the top through the roof at the front end of the fuel bed,
impinging upon the fuel and bringing about combustion, giving off intensely
heated gases which pass through the passage 8 into the heating furnace 13 rising
through the flue 11 at the back, returning through the flues of the boiler 1" from
the front end of which they enter the firebrick recuperator and thence pass off to
the chimney.
The recuperator may be of any suitable form-The one shown comprises a
series of vertical passages 11" 11° arranged in rows, the waste gases passing up the
passages 11 while the air for combustion is drawn down the adjoining passages 11º.
The air is admitted into the passages 11 at the top through openings 11' on the
front side controlled by regulating dampers 118 from the ground and after passing
down, the passages 11° and abstracting heat from their side walls, is allowed to
enter the combustion chamber 1 above and in front of the fuel bed, where
combustion takes place.
As already described the water in the trough under the fire bars is gradually
evaporated by the heat from the fuel above and the steam thus generated keeps
the fire bars comparatively cool by passing between them and prevents their
being burned away, while at the same time the steam in passing through the
incandescent fuel becomes decomposed with the result that the gases from
the fuel are very much enriched by those from the steam and a
heat is produced.
more intense
The loss of water in the trough from evaporation is made up by a simple ball
tap valve arrangement 14 (Fig. 6) in connection with the service water main so
that the water level shall remain constant.
Fig. 9 shows in vertical longitudinal section my invention applied in conjunction
with a
steam generator and a horizontal recuperator arranged below such
generator.
Fig. 10 is a plan, partly in horizontal section on line J K of Fig. 12.
Fig. 11 is a cross section on liue G H of Fig. 9.
Fig. 12 is a cross section partly on line C D and partly on line E F of Fig. 9.
As respects the construction and arrangement of the combustion chamber with
its fire grate water bottom and valve this modification resembles others already
described. Air entering at 11' travels along the passages 11° where it is heated,
then enters and rises within the vertical passages 11h into the chamber 11' in the
crown of the combustion chamber 1 whence it descends into the combustion
chamber by the ports 11' at the front thereof and passes over the bed of fuel on
the fire grate whose combustion the air thus supports; the flame and hot gases
pass from the combustion chamber 1 by the fire tubes 13 of the steam generator 1°
thence down into the flue 11 along it and descending thence into and passing
along the passages 11ª and away to the chimney, imparting during their travel
through the said flue and passages heat to the air that is on its way to the
combustion chamber.
In the several arrangements, wherein there is a water bottom, the ashes and
clinker falling between the fire bars into the water trough may be raked out from
time to time on pushing back the hinged flap valve forming the water seal which
valve will close by its own weight when released. Also the said several arrange-
ments may respectively be modified by dispensing with the water bottom and in
lieu thereof providing as already described for the introduction of live steam
into the ash pit below the fire bars by means of a pipe provided with a regulating
cock the ashpit below the grate being closed by a tight fitting door to prevent
access of air.
As will be readily understood it might be found convenient in some cases to use

page_text: both a water bottom and a steam supply below the fire grate; and my invention
hereinabove described may be applied in connection with evaporating pans and in
other cases where high temperatures are required.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1. A furnace constructed with a close combustion chamber a fire grate therein,
means for supplying heated air for surface combustion of fuel on said grate, and
a closed ash pit below the grate provided with a water bottom or with means for
supplying steam or with both in-suchwise that water vapor ascending within
the closed ash pit will serve to prevent excessive heating of the fire bars and
passing between them and through the mass of iguited fuel will be decomposed,
thereby affording additional combustible gases and aiding to produce intense
heat.
2. The method substantially as described with reference to the examples
illustrated, of employing in a furnace having a close combustion chamber and fire.
grate, heated air supplied above the fuel on the grate in conjunction with water
vapor caused to ascend through the grate and the burning fuel.
Dated this 28th day of February 1896.
W. Lloyd Wise,
JOHN GJERS.
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.