Improvements in the Construction and Working of Melting and Heating Furnaces.
Year: 1894

page_text: Date of Application, 7th Feb., 1894
Complete Specification Left, 5th Nov., 1894-Accepted, 12th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Construction and Working of Melting and
Heating Furnaces.
I, JOHN GJERS, of Ayresome Iron Works, Middlesbrough-on-Tees, in the
County of York, Ironmaster, do hereby declare the nature of this invention to be
as follows:-
This invention has reference to the construction and method of working of
melting and heating furnaces.
A furnace intended to be worked with solid fuel is according to my invention
constructed with combustion chambers having solid hearths and there is a clear
passage of considerable cross-sectional area between each combustion chamber and
the melting or heating chamber of the furnace so as to permit of ready access and
escape of the hot flame and products of combustion respectively before and after
they have done duty in the said melting or heating chamber of the furnace. Each
combustion chamber is in communication with a regenerator (or regenerators) that
is advantageously of more than the usual capacity for a given size of furnace
and the arrangement is such that heated air from one regenerator or set of
regenerators will be caused to impinge upon the surface of the fuel in that com-
bustion chamber which is for the time being in use, and wherein combustion will
occur, and the resulting flame and products of combustion will pass thence into the
melting or heating chamber of the furnace, and after doing duty therein, will escape
through the opposite combustion chamber and regenerator or regenerators, and
vice versa, the action being reversed from time to time, as well understood by the
improved methods hereinafter described.
One arrangement of such a furnace for burning solid fuel is as follows:-At each
end of a furnace body of suitable form with melting or heating chamber, there is
provided a combustion chamber of ample size, having a solid bottom adapted for
coal or other solid fuel. Each combustion chamber has one or more fire-doors for
stoking; poking holes at suitable parts of the sides and ends; and a slag hole with
spout at each side leading from the lowest point of the bottom, for running off the
slag resulting from the combustion of the fuel. Between each combustion chamber
and the melting or heating chamber of the furnace communication is established by
one large port or opening, which may be the full width of the furnace, so that
products of combustion passing from either combustion chamber into the body of
the furnace, and also the waste gases passing from the body of the furnace to the
regenerators, will not be interrupted by any division or other walls, such as those
in furnaces of ordinary type, the burning away of which walls causes so much
trouble and expense. The large port in my construction is so arranged as to direct
the flame down on the charge, though it may be otherwise arranged as for example
horizontal, as may be desired. The regenerators may be of any convenient con-
struction vertical or horizontal. Preferably each regenerator comprises a vertical
cylindrical iron casing and bottom, and a conical or domed top terminating in a
chimney of suitable size and height to afford sufficient draught, the inside and
bottom of the casing as also the chimney being lined with firebrick next to the
shell.
Each regenerator is by preference placed directly over the corresponding
combustion chainber, and there rises over the crown or arch above the combustion

page_text: chamber a firebrick flue of sufficient size to take the whole of the products of
combustion that leave the furnace on their way to the central flue of the
regenerator.
The filling of the regenerators may be cellular or parallel or circular walls, or
chequer work, or any appropriate system may be adopted for taking up waste
heat.
Each regenerator is carried on suitable girders and columns or walls, so that
none of its weight shall be on the roof of the combustion chamber.
On the top of each regenerator there is provided a damper or valve which can
be opened for admitting air or closed from the ground by a chain or other
contrivance. The top of each chimney is provided with a damper or valve which
can be opened or closed from the ground.
With such a furnace adapted for melting or heating steel or other refractory
material the mode of working is as follows viz. :-After a good fire has been
prepared in each combustion chamber, the chimney damper of both regenerators
being open the air inlet valve of one regenerator is closed; the chimney damper of
the other regenerator is then closed and its air inlet valve opened. Air then
passes in at this valve, through the one regenerator, and having by this time
become highly heated, the air impinges upon the fuel in the combustion chamber
below, whereby combustion takes place. The intense resulting heated flame and
gases pass through the large port or opening into the melting or heating chamber
of the furnace containing the charge to be melted or heated, and the waste gases
or products of combustion pass off by the large port or opening at the opposite end
of the furnace, thence up through the opposite combustion chamber and up and
through the regenerator at that end, where the greater portion of the heat is given
up to and stored in the walls of the cells, or chequer work, or other filling, the
remainder passing off by the chimney.
After this action has gone on for a sufficient length of time to considerably
reduce the temperature of one regenerator and increase that of the other, the
direction of flow of the flame and products of combustion is reversed. To this end
the air inlet valve that was open is closed, the other one opened, the chimney valve
that was closed is opened, the other one closed, and thus the combustion of the solid
fuel in the other combustion chamber is effected and the heat caused to travel in
the opposite direction, so heating up the regenerator through which air was
previously entering. Fresh fuel is introduced from time to time to the combustion
chamber that is being supplied with heated air from its regenerator or regenerators,
but the fire being allowed to burn down before reversing so that after reversing the
escaping products will pass over the fuel without impinging to any considerable
extent upon it on their way to the regenerator.
My invention can be applied in the construction of furnaces for treating ingots
preparatory to rolling, the ingots being introduced and placed (preferably)
vertically in the body of the furnace as in soaking pits, each opening for intro-
ducing ingots being provided with a cover; also to glass melting furnaces and
heating furnaces of all kinds requiring high temperatures.
In a furnace according to my invention for burning solid fuel practically the
whole of the heat due to the complete combustion of the fuel (excepting the small
proportion that may be lost by radiation from the sides of the combustion chamber)
will pass into the melting or heating chamber of the furnace; loss of initial heat
such as occurs with furnaces fired by gas (where the producer is often some distance
away from the furnace) may be obviated; the openings from the combustion
chambers to the melting or heating chamber of the furnace being each one wide
port there will as already indicated be no division walls to burn away and give
trouble as is in the usual type of gas fired regenerative furnaces, where both the
gas and air ports are utilized as passages for waste heat to regenerators and the
walls dividing one from another are continually burned away, necessitating costly
repairs. Where my furnace is constructed with regenerators above ground, whilst
they will take up practically no floor space that would otherwise be useful there

page_text: will be no danger of the regenerators being injured by the metal burning through
the bottom of the furnace as is frequently the case where regenerators are placed
under melting furnaces.
In some cases the large port or opening between each combustion chamber and
the heating chamber of the furnace, may be divided longitudinally by one or more
walls or divisions so that the flame from each combustion chamber will be divided
into two or more parts and directed into two or more separate heating chambers.
This arrangement is more particularly applicable to furnaces for heating ingots as
the wall between each pair of ports or passages serves to divide the flame and hot
gases escaping from the combustion chamber into two parts and tends to prevent
direct impact of said flame and hot gases upon the end surfaces of the ingots next
the combustion chambers.
My improved furnaces may be variously constructed, the body of the furnace
being of ordinary or other convenient form according to the purpose for which it is
to be used. Also various means may be provided for causing air to flow through
each regenerator in turn.
Thus instead of providing each regenerator with a chimney producing draught
as in the arrangement hereinbefore described, one chimney only may be used that
is adapted to be placed alternately in connection with each regenerator by a pipe
or passage the communication being controlled by a reversing valve arranged it
may be within a casing having an air inlet, the arrangement being such that when
the said valve is turned into a position to place one regenerator in communication
with the chimney, it will place the other in communication with the said air
inlet.
Again air may be forced alternately into each regenerator by a fan, or it may be
drawn through the regenerators, combustion chambers and melting or heating
chamber alternately in opposite directions by suction produced by a fan; or the air
may be both forced and drawn alternately in opposite directions by such means.
Also other suitable means such as steam jets may be used for forcing or drawing,
or both forcing and drawing, air alternately in opposite directions through the
regenerators, combustion chambers and melting or heating chamber. In the latter
case the steam nozzles may be so mounted at the upper ends of the regenerators
that they can be partly rotated so that each of them can be used alternately as
cjectors and injectors, so that when one is acting as an injector, the other is acting
as an ejector, and vice versa. In each of these cases the chimney or chimneys can
be dispensed with.
Improvements in the Construction and Working of Melting and
Heating Furnaces.
I, JOHN GJERS, of Ayresome Iron Works, Middlesbrough-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 :-
.
This invention has reference to the construction and method of working of
melting and heating furnaces.
A furnace intended to be worked with solid fuel is according to my invention
constructed with combustion chambers having solid hearths, and there is a clear

page_text: passage of considerable cross-sectional area between each combustion chamber and´
the melting or heating chamber of the furnace so as to permit of ready access and
escape of the hot flame and products of combustion, respectively before and after
they have done duty in the said melting or heating chamber. Each combustion
chamber is in communication with a regenerator (or regenerators) that is
advantageously of more than the usual capacity for a given size of furnace, and the
arrangement is such that heated air from one regenerator, or set of regenerators,
will be caused to impinge upon the surface of the fuel in that combustion chamber
which is for the time being in use, and wherein combustion will occur, and 'the
resulting flame and products of combustion will pass thence into the melting or
heating chamber of the furnace and after doing duty therein, will escape through
the opposite combustion chamber and regenerator or regenerators, and vice versa,
the action being reversed from time to time by the improved method hereinafter
described.
In the accompanying drawings,
Fig. 1 shows partly in longitudinal vertical section and partly in side
elevation, an arrangement of furnace for burning solid fuel according to this
invention.
Fig. 2 is a horizontal section thereof, on the line
of Fig. 1; and
Fig. 3 is a side elevation of the furnace to a smaller scale.
The remaining figures are hereinafter referred to.
I is the furnace body of suitable form with melting or heating chamber 2, at
each end of which is a combustion chamber 3 of ample size. Each combustion
chamber has a solid bottom 4 for holding coal or other solid fuel; also one or
more firedoors 5 for stoking, poking holes 6 at suitable parts of the sides and
ends, and a slag hole 7 with spout 7 at each side, leading from the lowest point of
the bottom, for running off the slag resulting from the combustion of the fuel.
Communication is established between the melting or heating chamber 2 and
each combustion chamber 3 by one large port or opening 8, which may advan-
tageously be the full width of the furnace as shown, so that products of
combustion passing from either combustion chamber into the melting or heating
chamber 2, and also the waste gases passing from the said chamber 2 to the
regenerators 9, will not be interrupted by any division or other walls, such as
those in furnaces of ordinary type, the burning away of which walls causes so
much trouble and expense. The large port 8, is, in the example shown,
inclined downwardly towards the bed of the chamber 2 so as to direct the flame
down on the charge, though it may be otherwise arranged, as for example
horizontal, as may be desired.
The regenerators 9 may be of any convenient construction, vertical or
horizontal. Preferably each regenerator comprises, as shown, a vertical cylin-
drical iron casing 10 with bottom 10", and a conical or domed top 11 terminating
in a chimney 12 of suitable size and height to afford sufficient draught, the inside
and bottom of the casing, as also the chimney, being lined with firebrick.
Each regenerator 9 is by preference placed directly over the corresponding
combustion chamber 3 as shown, and there rises over the crown or arch above the
combustion chamber, a firebrick flue 13 of sufficient size to take the whole of the
products of combustion that leave the furnace on their way to the central flue 14
o the regenerator.
The filling 14" of the regenerators may be cellular (Fig. 2); or it may
consist of parallel or circular walls, or chequer work; or any other appropriate
system may be adopted for taking up waste heat. 14 are cleaning holes through
which ashes and other dirt may be withdrawn from the regenerators from time
to time. These holes are normally closed by suitable means, such as a segmental
metal ring 14.
Each regenerator is carried on suitable girders 15 and columns 16 (or walls), 50
that none of its weight shall be on the roof of the combustion chamber 3.
On the top of each regenerator there is provided a damper or valve 17 which

page_text: can be opened for admitting air, or closed, from the ground, by a chain 18 or
other contrivance. The top of each chimney is provided with a damper or
valve 19 which can be opened or closed from the ground, by a chain 20 or other
contrivance.
With such a furnace adapted for melting or heating steel or other refractory
material, the mode of working is as follows viz. :-After a good fire has been
prepared in each combustion chamber 3,-the chimney damper 19 of both
regenerators and the fire doors 5 of both combustion chambers being open to
allow of this being done-the said fire doors are closed; and the fires supplied
with air from the body of the furnace until the regenerators have become
sufficiently heated, whereupon the air inlet valve 17 of one regenerator 9 is
closed; and the chimney damper 19 of the other regenerator is closed and its
air inlet valve 17 opened. Air then passes in at this valve through the one
regenerator, and having by this time become heated, the air impinges upon the
solid fuel 3 in the combustion chamber 3 below, whereby surface combustion
takes place. The intensely heated flame and gases resulting from the surface
combustion, passes through the large port or opening 8 into the melting or heating
chamber 2 containing the charge to be melted or heated, and the waste gases or
products of combustion pass off by the large port or opening 8 at the opposite
end of the furnace, thence up through the opposite combustion chamber 3, and up
and through the regenerator 9 at that end, where the greater portion of the heat
is given up to and stored in the walls of the cells, or chequer work, or other
filling 14", the remainder passing off by the chimney 12.
After this action has gone on for a sufficient length of time to considerably
reduce the temperature of one regenerator and increase that of the other, the
direction of flow of the flame and products of combustion is reversed. To this
end the air inlet valve 17 that was open is closed, the other one opened, the chimney
valve 19 that was closed is opened, the other one closed, and thus the combustion
of the solid fuel in the other combustion chamber is effected and the heat
caused to travel in the opposite direction, so heating up the regenerator 9
through which air was previously entering. Fresh fuel is introduced from time
to time or fed continuously by suitable means, to the combustion chamber that is
being supplied with heated air from its regenerator or regenerators, but the fire
is allowed to burn down, as shown at the right hand side of Fig. 1, before
reversing, so that after reversing, the escaping products will pass over the fuel 3ª,
without impinging to any considerable extent upon it, on their way to the
regenerator above.
Figs. 4 and 5 are similar views to Figs. 1 and 2 respectively, showing my
invention applied in the construction of underground furnaces for heating ingots,
slabs or blooms preparatory to rolling. When ingots 21 are to be heated, as in
the particular example shown, these are preferably placed vertically in the body I
of the underground furnace, being introduced through openings 22 provided with
removable covers 23.
In a furnace for burning solid fuel according to my invention, practically the
whole of the heat due to the complete combustion of the fuel (excepting the
small proportion that may be lost by radiation from the sides of the combustion
chambers), will pass into the melting or heating chamber of the furnace; loss of
in tial heat such as occurs with furnaces fired by gas (where the producer is often
some distance away from the furnace) can be obviated; and the openings 8 from the
combustion chambers to the melting or heating chamber of the furnace being each
cue wide port, there will, as already indicated, be no division walls to burn away
and give trouble as in the usual type of gas fired regenerative furnaces where both
the gas and air ports are utilised as passages for waste heat to regenerators, and
the walls dividing one from another are continually burned away, necessitating
costly repairs.
In some cases the large port or opening 8 between each combustion chamber and
the heating chamber of the furnace, may be divided longitudinally by one or more

page_text: wans or divisions 8", as snown for example, in norizontal section in Fig.
the flame from each combustion chamber 3 in turn is directed into each of two
separate heating chambers 2 through a pair of inclined ports or openings 8b. This
arrangement is more particularly applicable to furnaces for heating ingots, as the
wall 8 between each pair of ports or passages 8b serves to divide the flame and
hot gases escaping from the combustion chamber into two parts, and tends to
prevent direct impact of the said flame and hot gases upon the end surfaces of the
ingots next the combustion chambers.
My invention can also be applied to glass melting furnaces and heating furnaces
of all kinds requiring high temperatures.
My improved furnaces may be variously constructed, the body of the furnace
being of ordinary or other convenient form according to the purpose for which it
is to be used. Also various means may be provided for causing air to flow through
each regenerator in turn.
Thus instead of providing each regenerator with a chimney 12 as shown in
Fig. 3 for producing draught, one chimney 12 only may be used as shown in
Fig. 34, that can be placed alternately in connection with each regenerator by a
pipe or passage 26, the communication being controlled by a reversing valve 27
arranged it may be within a casing having an air inlet 28. As will be seen, the
arrangement is such that when the said valve is turned into a position to place
either regenerator in communication with the chimney, it will place the other in
communication with the said air inlet 28
Again air may be forced alternately into each regenerator by a fan, or it may be
drawn through the regenerators, combustion chambers, and melting or heating
chamber alternately in opposite directions by suction produced by a fan; or the
air may be both forced and drawn alternately in opposite directions by such means.
Also other suitable means such as a steam jet or jets may be used for forcing or
drawing, or for both forcing and drawing, air alternately in opposite directions
through the regenerators, combustion chambers and melting or heating chamber.
Fig. 3 shows an arrangement for this purpose wherein 29, 29ª are steam nozzles
mounted within the upper open ends of the regenerators 9 in such a manner that
they can be partly rotated so that each of them can be used alternately as an
injector and as an ejector so that when one of them, say 29, is acting as an injector,
the other 29ª can act as an ejector as shown, and vice versa alternately. In each of
these cases in which fans or steam jets are used, the chimney or chimneys can be
dispensed with. It will be obvious that a steam jet or jets might be used with the
arrangement shown in Fig. 34, but without the chimney 12, for forcing or drawing
air, or both drawing and forcing air through the furnace.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed 1 declare that what
I claim is
-:
1. A furnace 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 upon the surface of the fuel, the
resulting flame and hot gases then passing into a melting or heating chamber,
substantially as herein described
2. A regenerative melting or heating furnace in which there is provided between
each end of the melting or heating chamber and the corresponding regenerator,
or set of regenerators, a close combustion chamber having a solid hearth and
adapted to burn solid fuel, the arrangement being such that when the furnace
is in operation, highly heated air from one regenerator (or set of regenerators)
will be caused to impinge upon the surface of the solid fuel in the combustion
chamber for the time being in use and cause surface combustion of such fuel, and
the resulting flame and products of combustion will then pass into the melting
or heating chamber and after doing duty therein, will escape through the opposite

page_text: combustion chamber and regenerator, the action being reversed from time to time
as set forth.
3. The improved regenerative furnaces constructed arranged and operating
substantially as herein before described with reference respectively to and shown in
Figs. 1, 2 and 3; and in Figs. 4 and 5 of the drawings annexed, whether a single
wide port or opening 8 be provided between each combustion chamber and the
melting or heating chamber, as in Figs. 1 and 2; or two or more large openings 8ª
be used, as in Figs. 4 and 5, and whether a single chimney (Fig. 34) or two chimneys
(Fig. 3), or other means such as a fan or fans, or steam jet or jets be employed for
producing the necessary draught for working the furnaces.
Dated this 5th day of November 1894.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.