IMPROVEMENTS IN FURNACES FOR HEATING AND MELTING METALS, AND FOR OTHER PURPOSES
Year: 1878

page_text: LETTERS PATENT to James Thomas Sheldon, of Wolverhampton, in the County
of Stafford, Furnace Builder, for the Invention of "IMPROVEMENTS IN
FURNACES FOR HEATING AND MELTING METALS, AND FOR OTHER PURPOSES."
Sealed the 30th August 1878 and dated the 2nd March 1878
PROVISIONAL SPECIFICATION left by the said James Thomas Sheldon at
the Office of the Commissioners of Patents on the 2nd March 1878.
JAMES THOMAS SHELDON, of Wolverhampton, in the County of Stafford, Furnace
Builder. "IMPROVEMENTS IN FURNACES FOR HEATING AND MELTING METALS, AND
FOR OTHER PURPOSES."
The fuel is charged into one or more retorts, having their back ends, which are
open, connected to the ordinary furnace grate. Air flues are arranged along parts
of the furnace and main flue therefrom. Cold air passes through the said air flues
(in which it is heated) to flues formed around the retorts. The air on reaching the
retorts is at a high temperature, and thus heats the fuel in the retorts from which
gas is consequently discharged into the furnace grate. Openings are formed from
the flues around the retorts into the furnace grate, and the hot air thus meets the
gas as it is discharged from the retorts and a thorough combustion is obtained.
When as much gas as is practicable is expelled from the fuel in a retort, the fuel is
pushed from the retort into the furnaco grate, and fresh fuel is charged into the
retort.
The furnace is "got up" by lighting a fire in the furnace grate, and also in the
retorts, air being allowed to pass into the retorts until the heat is got up.
As an instance of the application of this Invention, I will describe the method I
prefer to adopt for a puddling furnace. In this case, the retorts are placed at the
end of the furnace grate, and in a position inclining downwards thereto. The main
flue from the furnace is formed as a culvert underneath the furnace, the chimney
being carried over the retorts. The products of combustion pass from the under-
ground flue up a vertical flue at each side of the retorts, and thence through cross

page_text: flues over the arch of the retort bed into the chimney. The air flues are arranged
in the bottom of the main flue underneath the furnace, and pass from thence
In the case of
through the back of the furnace to the flues around the retorts.
puddling furnaces having the chimney in the usual position, the air flues may
surround the lower part of the chimney and pass from thence through the back of
the furnace to the flues around the retorts.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Thomas Sheldon in the Great Seal Patent Office on the
31st August 1878.
$6
JAMES THOMAS SHELDON, of Wolverhampton, in the County of Stafford, Furnace
Builder. IMPROVEMENTS IN FURNACES FOR HEATING AND MELTING METALS, AND
FOR OTHER PURPOSES."
According to one modification of this Invention, the fuel is charged into one or
more inclined retorts or into a producer, having its back end, which is open, con-
nected to the ordinary furnace grate. Air flues are arranged along the main flue
from the furnace, which is preferably carried in a culvert under ground. Cold air
passes through the said air flues (in which it is heated) to flues formed around the
retorts or producer. The air on reaching the retorts or producer is at a high
temperature, and thus heats the fuel in the retorts or producer, from which gas is
consequently discharged into the furnace grate. Openings are formed from the
Blues around the retorts or producer into the furnace grate, and the hot air thus
meets the gas as it is discharged from the retorts or producer, and a thorough
combustion is obtained. When as much gas as is practicable is expelled from the
fuel in a retort or producer, the fuel is pushed from the retort or producer into the
furnace grate, and fresh fuel is charged into the retort or producer.
The furnace is "got up" by lighting a fire in the furnace grate and also in the
retorts or producer, air being allowed to pass into the retorts or producer until the
heat is got up.
It will be seen that according to this Invention the air is heated, and the gas
therefore expelled from the fuel by means of the waste heat from the furnace.
According to another modification of this Invention, and the one which I prefer
to employ, the escaping products of combustion act directly on the retorts or
producer. The air for admixture with the gases is in this case heated by passing
along flues heated by the escaping products of combustion, and then enters the
furnace grate directly in front of the retorts or producer, without first passing
around the said retorts or producer.
Having thus stated the nature of the said Invention, I will now proceed to
particularly describe the manner of carrying out the same with reference to the
accompanying Drawings and the letters of reference marked thereon.
The Drawings are to a scale of 2 feet to an inch.

page_text: Figure I represents a longitudinal section through a puddling furnace constructed
according to my second modification.
Figure 2, a cross section through the underground flues taken on line b, b, of
Figure 1.
Figure 3, a vertical section through the chimney stack and retorts taken on line
c, c, of Figure 1.
And Figure 4, a sectional plan of the underground flues taken on line d, d, of
Figure 2.
The same letters of reference occurring upon any of the views 1, 2, 3, and 4,
indicate corresponding parts.
A is the furnace grate; B, B, etc., the flue by which the products of combustion
escape to the chimney; C, C, etc., the air flues; and D, D, the retorts.
The direction of the escaping products of combustion is indicated by full line
arrows, and the direction of the air by dotted line arrows. The products of com-
bustion descend after leaving the neck of the furnace, and at the bottom of the
vertical flue pass into a horizontal arched flue between the inner and outer air flues.
The said products pass along this horizontal flue direct into the base of the
chimney stack, which is shewn somewhat wider at the base than is usual to admit
of the flues. The said products pass thence around the retorts, and afterwards
away up the chimney. The air is drawn in (by means of the draught of the
furnace) at the opening E at the back of the furnace, from whence it passes down
to the outer air flue, when it traverses along the two sides and arched top thereof,
and then descends through the opening F (see Figure 1, and shewn by dotted lines
Figure 4) into the inner air flue, and passing along this flue rises at the chimney
end, up the narrow flue in the chimney wall. When this last-mentioned flue
reaches the retort bed it divides, passing up each side of the retort bed and spread-
ing out on each side of the chimney stack (to maintain the proper area of flue), and
then rises and delivers itself at each side into the flue over the furnace grate, and
thence down through a number of vertical holes a, a, etc., into the furnace, and just
in front of the retorts.
The retorts may be of earthenware or of any suitable material, according to the
temperature of the escaping products, and are supported by narrow arches G, G.
It will be seen (Figure 2) that the exterior air flue surrounds the main flue, and
that the interior air flue is surrounded by the main flue. By this means a very
high temperature of air may be obtained.
Figures 5 and 6 are respectively a longitudinal section and a cross section through
a producer as applied to my improved furnace.
The illustration will be sufficiently clear without need for further description, as
the arrangement is precisely the same as for the furnace, illustrated by Figures
1, 2, 3, and 4, except that a brick producer is substituted for retorts. The escaping
products of combustion pass around the producer in the same manner as around the
retorts.
Referring to Figures 2 and 6, e, e, are bricks carried across the flues at different
points along the line of the flues to support the arches.
The brickwork of the furnace is supported by iron plates, bars, and rods, in
manner well known to furnace builders, and I have therefore not illustrated all
such plates, etc.
My first modification will now be readily understood without need for special
illustration. The construction of the furnace in this case is the same as illustrated
for my second modification, except that the heated air passes directly around the
retorts or producer, and from thence through openings in the wall H into the
furnace. The products of combustion are carried in a separate flue passing up each
side of the retort or producer bed into the chimney stack, but are divided off from
the bed by brick work so as not to be in contact with the retorts or producer. The
fuel in the retorts or producer is thus heated by the hot air. This modification is
suitable only with furnaces having a very high temperature of escaping products,
and in any case I prefer to use my second inodification.

page_text: One or both modifications of the Invention are of course applicable to all furnaces
in which the escaping products of combustion are sufficiently high to expel a con-
siderable portion of the more volatile gases from the fuel.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that I do not limit
myself to the exact details as described and shewn, as such may be varied without
departing from the nature of my Invention, but what I claim as my Invention and
desire to secure by Letters Patent is,-
1st. The application of horizontal or inclined retorts or producers to the furnace
grates of heating and melting furnaces, and to other furnaces from which the
products of combustion pass away at a very high temperature as aforesaid, such
retorts or producers being heated by the hot air, substantially as and for the purpose
herein-before described.
2nd. The application of the retorts or producers mentioned in my first claim to
the furnace grates of heating and melting furnaces, and to other furnaces from
which the products of combustion pass away at a sufficiently high temperature to
expel a considerable portion of the more volatile gases from the fuel, such retorts or
producers being heated directly by means of the escaping products of combustion,
substantially as and for the purpose herein-before described, and illustrated by the
Drawings.
3rd. Heating air by means of air flues constructed in connection with the furnaces
mentioned in my First and Second claims, substantially in the manner illustrated
and described, and admitting the air so heated, either first into the retort or producer
bed (in the case only of furnaces having a very high temperature of escaping gas)
to heat the said retorts or producer, and thence into the furnace, substantially as
and for the purpose herein described, or admitting the said heated air direct into
the furnace, substantially as and for the purpose herein described, and illustrated by
the Drawings.
4th. The combination of the retorts or producer with the method of heating the
air, substantially as and for the purpose herein described, and illustrated by the
Drawings.
In witness whereof, I, the said James Thomas Sheldon, have hereunto set my
hand and seal, this Twenty-sixth day of August, in the year of our Lord
One thousand eight hundred and seventy-eight.
Witness,
STEPHEN WATKINS,
Assoc. Inst. C.E.,
Patent Office,
Wolverhampton.
J. T. SHELDON. (L.S.)