Improvements in or connected with Reverberatory Furnaces for Puddling or Smelting Iron and for other purposes.
Year: 1890

page_text: Date of Application, 30th Oct., 1890
Complete Specification Left, 30th July, 1891-Accepied, 24th Oct., 1891
.
PROVISIONAL SPECIFICATION.
Improvements in or connected with Reverberatory Furnaces for
Puddling or Smelting Iron and for other purposes.
We, JOSEPH VON LANGER, Engineer, and LEONARD COOPER, Iron Merchant,
both of 32, Park Row, Leeds, Yorkshire, do hereby declare the nature of this
invention to be as follows:-
This invention relates chiefly. to reversible reverberatory furnaces of the type
known as the Pietzka furnace, which contains two hearths adapted to turn on a
vertical axis, so as to reverse their position in relation to the flues, and is provided
with means for lifting the said hearths before they are turned.
The improvements relate firstly to the means for lifting and turning the furnace,
secondly to the means for heating the air previous to combustion, and thirdly, to
the shape of the contact surfaces between the movable furnace and the stationary
part of the flue or gas inlet.
Hitherto the reversible body of the furnace has been mounted on the platform
of a ram or piston which could be raised by hydraulic pressure in a cylinder
placed vertically under the centre of the furnace in a recess of the foundation,
the said piston serving also as a pivot in reversing the furnace.
In order to obtain a more accurate motion of the furnace, and gain better
access to the lifting apparatus, I place the cylinder and and other lifting mechanism
vertically above the centre of the furnace, and support it by a bridge or other
suitable means, while the bottom of the movable furnace body is guided by a
pivot which may be supported by a step-bearing. The furnace body is therefore
guided both at the top and at the bottom.
In the case of puddling furnaces, this arrangement has the advantage, that the
same bridge or stand which supports the lifting apparatus, may also serve as
support for a puddling machine, to be used for both hearths.
In order to cool the hearth plate or sole of the furnace and at the same time to
heat the air necessary for combustion in the furnace, I apply underneath the
hearth-plates a specially constructed air heating apparatus, through which the air
is conducted on its way to the furnace, either by suction or by pressure. The said
air heating apparatus is a rectangular chamber of sheet metal provided with
transverse partitions arranged. in such a manner, that the air entering at one end
(through a tube at the bottom of the chamber) is obliged to follow a zig-zag course
A double
in passing through the chamber to the outlet at the opposite end.
zig-zag course may be formed by dividing the chamber longitudinally into two
halves, and providing a series of transverse partitions in each half. One or more of
the partitions may be perforated.
In the Pietzka furnace, as usually made, a vertical section through the contact
surface between the ends of the movable furnace body and its seat is a straight
line, and the surface itself is part of a straight cone.
The said surface may however, form parts of two parallel and coaxial cones and
joined together by a narrow annular strip; and a vertical section through the
contact surface may be broken or a curved line, the broken line being composed of
two parallel inclined lines joined together by a short horizontal line.
These furnaces may be used for puddling, heating or smelting, and may be heated
with solid fuel or with gas. Although the furnace is reversible, the flame passes
through the same always in the same direction. In case of gas-heated furnaces, we
place the gas generator preferably close to the furnace, and combine the latter with
la recunerator

page_text: The recuperator may be heated directly by the generators, in case the movable
furnace body has been turned out at a right angle for repairs.
We prefer to heat the air first by blowing it through the air heating chamber
situated underneath the hearth plates, as described above, and subsequently con-
ducting it through the recuperator.
Dated this 30th day of October 1890.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in or connected with Reverberatory Furnaces for
Puddling or Smelting Iron and for other purposes.
We, JOSEPH VON LANGER, Engineer, and LEONARD COOPER, Iron Merchant,
both of 32, Park Row, Leeds, Yorkshire, 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 relates chiefly to reversible reverberatory furnaces of the type
known as the Pietzka furnace, which contains two hearths adapted to turn on a
vertical axis, so as to reverse their position in relation to the flues, and which is
provided with means for lifting the said hearths before they are turned.
Hitherto the reversible body of the furnace has been mounted on the platform of
a ram or piston which could be raised by hydraulic pressure in a cylinder placed
vertically under the centre of the furnace in a recess of the foundation, the said
piston serving also as a pivot in reversing the furnace.
In order to obtain a more accurate motion of the furnace, and gain better access
to the lifting apparatus, we place the cylinder and other lifting mechanism vertically
above the centre of the furnace, and support it by a bridge or other suitable means,
while the bottom of the moveable furnace body is guided by a pivot which may be
supported by a step-bearing. The furnace-body is therefore guided both at the top
and at the bottom.
In the case of puddling furnaces, this arrangement has the advantage, that the
same bridge or stand which supports the lifting apparatus may also serve as support
for a movable puddling machine, to be used for both hearths.
In the following description reference will be made to the accompanying drawing,
of which
Fig. 1 is a longitudinal vertical section of a duplex furnace and gas generators
embodying our improvements,
Fig. 2 is a cross section of the furnace and recuperator, and Fig. 3 a horizontal
section of the whole plant, comprising gas generators, furnace and recuperator.
In the drawings, A, A, represent a pair of gas generators, B, B, the two hearths
of the duplex furnace, C, C Hues for the waste furnace gases, D, D, the recuperator.
As shown by Fig. 1 the moveable part of the furnace is supported in the centre
by a frame work TT, and the latter is suspended from a vertical piston rod t by
means of a joint, which allows the furnace to turn on the axis of the piston rod.
The latter carries at the top a piston situated in a hydraulic cylinder H. This
cylinder is mounted on a stage or bridge S, which is supported by four columns s, s,
placed so as not to interfere with the motion of the furnace body.
The bottom plate of the frame or housing T has a pivot which is guided in a
bearing U situated in a recess of the floor."
For reversing the furnace, pressure water is admitted under the piston in the
cylinder H, whereby the frame T is lifted and with it the moveable furnace. The
latter, after having been lifted sufficiently, is turned horizontally on the axis of
the piston rod and pivot, until the two hearths B and B have exchanged their
position; and then the furnace is dropped on its seat by allowing pressure water to
escape from the bottom of the cylinder H.

page_text: R represents a puddling machine mounted on the bridge S, S.
Where several puddling furnaces are employed, the bridge or stage may extend
over a series of furnaces and carry the rails for a travelling crane constructed in
such a manner, that the same crane may be used for lifting any of the reversible
furnaces, and for lowering it again, after the furnace has been turned.
In such a
case the hydraulic cylinder H, with piston and piston rod, would be replaced by
the lifting apparatus of the travelling crane.
In the Pietzka furnace, as usually made, a vertical section through the contact
surface between the ends of the moveable furnace body and its seat is a straight
line, and the surface itself is part of a straight cone.
The said surface may, however, form parts of two parallel and coaxial cones
joined together by a narrow annular strip, and a vertical section through the
contact surface may be a broken or a curved line, the broken line being composed
of two parallel inclined lines joined together by a short horizontal line, as shown
in Fig. 1, where K' K² represent the contact surfaces.
Our improved furnaces may be used for puddling, heating or smelting, and may
be heated with solid fuel or with gas. In the case of gas-heated furnaces, we place
the gas generator preferably close to the furnace, and combine the latter with a
recuperator which is preferably placed underground along the furnace, as shown,
but which may also be arranged vertically.
The recuperator may be heated directly by the generators, in case the moveable
furnace body has been turned out at a right angle.
We prefer, to heat the air, by first blowing it through the air heating chamber
situated underneath the hearth plates, and subsequently conducting it through the
recuperator.
An air heating chamber M is formed underneath the hearth plates by means of
I irons and metal plates, as shown by the drawings. The said air chamber M has
in the bottom two diametrically opposite openings, provided with short tubes,
one serving for the admission of a cold air blast, and one 1 serving for the outlet
of heated air, and the said chamber contains vertical partitions or deflecting plates
which force the air to take a zig-zag course, while travelling from 1 to 12, and which
may be perforated.
The waste furnace gases travel partly through the flue C into the chimney D',
which may be utilized for raising the steam necessary to produce water gas, and
partly through the flue C, into the recuperator D, from which they escape through
a flue G.
The air which has already been heated in the chamber M passes through the
underground passage R to the flue E leading to the recuperator, and after having
been further heated by the same, the air flows through the flue F leading to the
generators, A., A. A part of the hot air ascends through the vertical passage O
situated between the two gas outlets of the generators, and then mixes with the
heating gases supplied by the same to the mouth J¹ of the furnace. Another part
of the hot air is drawn through an injector apparatus P (preferably one of Körting's)
which blows the same into the air nozzles that supply the generators A, A. A
Körting injector or other blast apparatus may also be placed in the flue F.
The recuperator may be of any approved construction, but preferably like that
described in the Specification of Patent No. 6400 1890.
In the drawings J, J₂ represent the inlet and outlet of the moveable furnace
body, b is the partition between the two hearths, and are the end walls,
3, the furnace doors.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we wish it to be under-
stood, that the following clauses are not intented to include any improvements covered
by the Letters Patent No. 6399 of 1890. With this reservation we claim ;
1. In a reversible duplex furnace, the combination of a reversible furnace body,
with means for suspending the same and for guiding it along a vertical axis, and a

page_text: stage or bridge carrying apparatus for lifting the furnace from the top, substantially
as described.
2. In a reversible duplex puddling furnace, the combination of the reversible
furnace body, with a pivotal frame adapted to support and guide the said furnace
body in the centre, and a stage or bridge built over the furnace and carrying a
puddling machine as well as apparatus for lifting the said pivotal frame, substantially
as described.
3. A reversible duplex furnace, having stepped conical contact surfaces between
the moveable furnace body and the stationary seats, substantially as described.
4. The combination of a reversible duplex furnace having an air heating chamber
situated underneath the furnace floor, with a pair of gas generators placed close to
the head or mouth of the furnace, and a recuperator placed underground alongside
the furnace, the whole being arranged as shown by the drawings and adapted to
operate substantially as described.
5. In reversible duplex furnaces, an air heating chamber situated underneath the
hearth plate, and having transverse partitions or deflecting plates with or without
perforations, substantially as described.
6. The combination of a reversible duplex furnace having an air heating chamber
underneath the hearth plate, with a pair of gas generators and a recuperator, the
waste gas flues, air passages, blast producers and valves being arranged in such a
manner, that the air required by the generators and furnace is first heated under
the hearth plate and then in the recuperator, substantially as described.
7. A furnace plant comprising a reversible duplex furnace provided with an air
heating chamber underneath the hearth plate, a direct chimney flue provided with
a steam generator, and a recuperator heated by a portion of the waste furnace gases
through a side flue, substantially as described.
Dated this 29th day of July 1891
FAIRFAX & WETTER,
433, Strand, London, Agents.