An improvement in the Construction or Open Hearth or Tank Furnaces for Melting Iron and Steel and other Purposes.
Year: 1885

page_text: An improvement in the Construction or Open Hearth or Tank
Furnaces for Melting Iron and Steel and other Purposes.
I, FREDERICK SIEMENS, of N° 12 Queen Anne's Gate, Westminster in the
County of Middlesex, Engineer, do hereby declare the nature of my invention
for "AN IMPROVEMENT IN THE CONSTRUCTION OF OPEN HEARTH OR TANK
FURNACES FOR MELTING IRON AND STEEL AND OTHER PURPOSES" and in what
manner the saine is to be performed to be particularly described and ascertained
in and by the following statement :-
In the working of open hearth iron and steel melting furnaces and tank furnaces
for other purposes it is often necessary to repair the bed or basin of the furnace,
especially the upper parts of the sides of the bed which are often acted on by slag
or other substances and are frequently exposed to the full furnace heat without
being protected like the lower parts by the metal or molten material covering
them. My invention relates to a construction of furnace in such a manner as to
give access for repairing and renewing the bed and especially the most vulnerable
parts of it without disturbing the roof or other parts of the structure.
The accompanying drawings shew a regenerative gas furnace of circular form as an
illustration of how my invention can be carried out practically. Fig. 1 is a section
on the line X X of fig. 2 which is a plan taken on the line Y Y of fig. 1.
A transverse central section is shewn at Fig. 3; figs. 4 and 5 are part transverse
sections to an enlarged scale at W W and Z Z of fig. 2 respectively, and fig. 6 is a
part external elevation of the bed and roof supports, which are shewn in a some-
what modified form in the part elevation fig. 7 and part section fig. 8. The
furnace bed A, which I make considerably deeper than usual, is enclosed in a metal
casing B, at the periphery of which at intervals apart a number of struts C and
columns c or brackets C extend upwards to carry a ring D on which is built the
furnace roof E. As the roof rests on the ring D it is supported independently of
the brickwork and lining of the bed A, which can therefore be repaired and
renewed without interfering with the stability of the superstructure. The bed A
is made deep in order to retain in it a great quantity of molten metal on which
the fused slag and other matters float. As these matters act on the zone of
bricks F forming the upper layer of the bed, I make these bricks removeable,
having free access to them from without through the spaces between the struts

page_text: or brackets C¹. The bricks F are inserted between the wall of the bed and the
ring D and may be kept in position, as shewn in fig. 8, by keys G driven between
them and the brackets C. A tap-hole H is provided at the bottom of the bed, but
another tap-hole K at a higher level may be employed to run off a charge, which
is a small quantity as compared with the total contents of the bed. By the tap-
hole K only the upper portion of the metal and slag can be run off. When it is
desired to run off metal with little or no slag, I form the tap-hole as shewn at L
opening from a basin separated from the rest of the bed by a partition M. On
opening the tap-hole L, metal overflowing the partition M can be run out until the
floating slag is reached when the tap hole can be closed and the slag run out by
the tap hole K; or K may be higher than the partition M, and the slag may be
tapped out by it before the withdrawal of a charge or from time to time inde-
pendently of the withdrawal of any portion of the metal. N and O are the flues
for air and gas coming from the one set of regenerator chambers and forming a
flame which sweeps round the furnace chamber, the products of combustion passing
by the flues N¹ and O¹ to the other set of regenerators, and conversely. Although
I have in the drawings shewn a furnace chamber of circular form, it might
obviously be made of elliptical, semi-circular or horse-shoe form, in which the flame
can sweep round as described. Or it might be of rectangular, oval or other form
with the flame entering by flues at one end or side to pass right across the furnace,
the products of combustion passing away by flues at the opposite end or side. In
all cases it is of advantage to make the bed of the furnace as shewn in the
drawings, accessible on all sides as well as below.
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. Constructing an open hearth or tank furnace with its roof supported inde-
pendently of the bed so as to give free access for removing and replacing the
lining of the upper layer of the bed, substantially as herein described.
Da thin 1st day of June 1885