Improvements in Regenerative Furnaces, and in the Method of Operating the same.
Year: 1896

page_text: Date of Application, 16th Apr., 1896-Accepted, 30th May, 1896
COMPLETE SPECIFICATION.
Improvements in Regenerative Furnaces, and in the Method of
Operating the same.
1, SYDNEY PITT of Sutton in the County of Surrey Gentleman do hereby
declare the nature of this invention (which has been communicated to me from
abroad by Henry Lawrence Gantt, of Norristown, in the County of Montgomery,
and State of Pennsylvania, U.S.A., Mechanical and Metallurgical Engineer) and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates to the production of high temperatures, and high
temperatures that will produce reducing effects on the material treated.
The invention involves a new method of operation, as well as an improved
furnace of the regenerative class by which very high temperatures may be obtained
from the use of solid fuel.
The method consists in first causing a solid carbon fuel to be burnt to produce
carbonic oxide (CO), then causing the. carbonic oxide to be burnt to carbonic
acid (CO), and by means of the high temperature produced thereby heating the
air supplied to the fuel to burn it to carbonic oxide (CO), and the air supplied to
the carbonic oxide (CO) to burn it to carbonic acid (CO2) by the regenerative
action of the heat due to the complete conversion of carbon to carbonic acid (CO);
the carbonic oxide (CO) from the primary burning of the fuel being caused to act
directly on the material to be treated where reducing effects are desired.
The heat being produced by this method by reverse cycles of regenerative
operations is accumulated and is consequently very intense.
The furnace devised by me, to carry out this method of producing high tempera-
ture, has two regenerator chambers, connected by flues or passages to the solid fuel
chamber or chambers, which communicate with or constitute the hearth or hearths
where the material is treated, the adjacent ends of the regenerator chambers
nearest to the combustion and treating chambers being connected together by flues
or openings, by means of which the air which is highly heated as it passes
alternately through each regenerator chamber is allowed partly to flow into the
other regenerator chamber, and there in its highly heated condition combines with
the gas from the fuel to complete the combustion of the same. In the preferred
form of furnace, and that shown in the drawings, which I will now refer to, the
treating hearth is located between two solid fuel chambers, and said hearth and fuel
chambers are located on the tops of the regenerator chambers. Heating chambers
as auxiliary to the regenerator chambers, and means for forcing and reversing the
air through the furnace, are also:shown.
Figure 1 is a vertical section of my improved furnace on the line 1, 1,
Figure 2;
Figure 2 is a vertical section on the line 2, 2, Figure 4;
Figure 3 is a vertical section on the line 3, 3, Figure 2;
Figure 4 is a horizontal section on the line 4, 4, Figures 1 and 2; and
Figure 5 is a sectional view similar to the upper part of Figure 1, showing a
slight modification in construction.
The hearth A or chamber to contain the material to be treated, is located in the
central upper part of the furnace, its roof is provided with openings A' A', covered
by the slides B B', which are perforated to afford access to the hearth for the
admission of the material thereto, when the slides are pulled out, said perforations
being over solid parts of the roof when the slides are closed, as shown. The

page_text: material is passed down the chamber C to the hearth, and this chamber is covered
by the cap C, and the material is removed from the hearth through the
opening A³.
At the sides of the hearth A are located the solid fuel chambers D and D', and
these have communication with the hearth through the flues D', D', and with the
two regenerator chambers E and E, through the flues E and E. These
regenerator chambers are located beneath the fuel chambers D and D', and are
filled,, with the exception of space at their upper ends, with checker work or
bricks E, arranged in the usual manner of heat regenerative devices to absorb and
give up the heat of the products of combustion.
The upper ends of the two chambers E E' have communication with each other
through the flues or openings F F, and their lower ends are open to the lower
ends of the chambers G'G', respectively, through the holes G, G³ in the dividing
wall.
These chambers G and G are filled to within a short distance of their upper
ends with checker work or bricks G and in their outer walls oppositely arranged
are the flues or openings H H', and between them is formed the recess H2.
A shaft I extends across the upper ends of the chambers G G¹, through the
recess H2, and into the flues H H, and on the ends of this shaft in flues H H' are
secured the fans or blowers J J', which are so made as to cause currents to flow in
the same direction when the shaft is rotated. The central part of the shaft I is
supported in hanger bearings K K, and between these bearings are the pulleys L,
L, L, the outer ones L, L, being loose on the shaft and the central one Li
keyed or otherwise secured thereto. These pulleys are adapted to carry driving
belts, one straight and the other crossed, arranged and controlled by shifters in such
manner that the shaft may be rotated in the two directions as desired, in the
ordinary and well-known way.
The operation of the furnace, is as follows:-A fire of coke, anthracite coal or
other solid carbon fuel is started in one of the fuel chambers, say D', the fans are
rotated so as to force the air through chamber G', regenerator chamber E', to
chamber D', exhausting from the chamber D1, through hearth A, fuel chamber D,
regenerator chamber E and chamber G. The fuel in D' is thus burned to
carbonic oxide which passes through hearth A, fuel chamber D to chamber E
where said carbonic oxide is burnt to carbonic acid by the air which passes from
the chamber E through the flues F, the products of combustion being now at a
high temperature imparts most of the heat to the checker bricks in E, the checker
bricks in G being also heated as the gases pass through the said chamber to be
discharged at its upper end. After running the furnace in this manner for some
time, the direction of rotation of the fans is reversed, the air being now forced
down through the chamber G, where it is heated, up through the chamber E, where
it becomes highly heated by passing over the checker bricks in this chamber, which
are very hot, into the fuel chamber D, which is also supplied with fuel and which
fuel is burned to carbonic oxide at a very high temperature, and passes through the
bearth, acting on the material therein, from whence it passes through D¹ to
chamber E, said carbonic oxide here meeting with the highly heated air coming
from the chamber E, through the flues F F is burnt at a very high temperature to
carbonic acid, which gives up most of its heat to the checker brick in E, and the
greater part of the remainder of its hent to the bricks in chamber G, before
finally escaping therefrom. After running in this way for some time, the currents
of air and gases are again reversed, passing through the furnace as first described,
and these reversals are caused to occur at suitable intervals, the resulting effect
being a very high temperature; and it will be observed that as nothing but highly
heated carbonie oxide passes into the hearth, a powerful reducing action is had on
the material there being treated.
Of course the temperature of the furnace and the amount of combustion in the
regenerator chambers will be governed and determined by the amount of air
admitted from one regeneration to another through the passage or passages F F.

page_text: In Figure 5 I have shown a slight modification of the construction already
described, that is to say, in this figure there is but a single chamber, to the opposite.
sides of which the flues E E respectively lead. This chamber is provided with a
suitable cover. The material to be treated may be mixed with the fuel in this.
chamber or as shown the material may be placed in a crucible surrounded by the
fuel in the chamber.
All the parts of the furnace submitted to the highly heated gases and air will be
preferably formed or lined with magnesite bricks or fire-clay.
In my improved organization and method of operation, the regenerator chambers.
are respectively what are known as single surface regenerators, that is to say, the
highly heated gases or products of combustion pass out directly through the same
regenerator chamber through which the incoming air to be preheated passes.
Having now particularly described and ascertained the nature of my said:
invention, and in what manner the same is to be performed, I declare that what.
I claim is-
1. The improved method of operating regenerative furnaces, which consists in
supplying heated air to a solid carbon fuel to burn it to carbonic oxide, (CO),.
causing the carbonic oxide to act directly on the material to be reduced, then
supplying air to the carbonic oxide to burn it to carbonic acid (CO,), thereby
developing a high heat, extracting and storing such heat, and then causing the air
which is supplied to the fuel to burn it to carbonic oxide and the air which is
supplied to the carbonic oxide to burn it to carbonic acid to take up such stored
heat, such operation being continned or repeated, substantially as and for the
purpose set forth.
2. In a regenerative furnace, the combination of a chamber adapted to hold a
solid fuel, two single surface regenerator, chambers connected at their inner ends.
by a passage of which the fuel chamber forms a part, through each of which
regenerator chambers the products of combustion alternately pass out and the
incoming air to be heated alternately passes into the fuel chamber, means for
reversing the operation of the furnace, a passage connecting said two regenerator
chambers at a point between the fuel chamber and their outer ends, whereby a part
of the incoming heated air passing in through one of said regenerator chambers on
the way to the fuel chamber is diverted into the other regenerator chamber
(through the passage connecting them) to complete therein the combustion of
the gases from the fuel chamber passing out therethrough, substantially as set
forth.
3. In a high temperature furnace, the combination of two chambers adapted to
hold solid fuel, a hearth located between these chambers and connected therewith
by flues, two regenerator chambers, each connected by passages or flues to one of
the fuel chambers, a passage or flue connecting the regenerator chambers together,
and means for reversing the direction of air through the regenerator chambers, the
fuel chambers and the hearth.
4. In a high temperature furnace, the combination of two chambers adapted to
hold solid fuel, a hearth located between these chambers and connected therewith
by flues, two regenerator chambers, each connected by passages or flues to one of
the fuel chambers, a passage or flue connecting the regenerator chambers together,
two heating chambers containing checker bricks connected at their lower ends to
the lower ends of the regenerator chambers, and fans or blowers located at the
upper parts of these heating chambers, operated as described to alternately force
air through and exhaust from these chambers and the other parts of the
furnace.
5. A regenerative furnace, comprising the combination of a chamber for the
combustion of fuel, two single surface regenerator chambers connected at their
inner ends by a passage of which such combustion chamber forms a part, and also
connected by a passage, for the admissiou of air from one to the other, at a point
between the combustion chamber and their outer ends, and means for reversing the

page_text: operation of the furnace, whereby a part of the heated air passing in through one
of said regenerator chambers on the way to the combustion chamber is diverted
into the other regenerator chamber to complete therein the combustion of the gases
passing therethrough from the combustion chamber.
Dated this 16th day of Anail 1000