Improvements in Melting Furnaces.
Year: 1892

page_text: Date of Application, 15th Mar., 1892-Accepted, 4th Mar., 1893
COMPLETE SPECIFICATION.
Improvements in Melting Furnaces.
I THOMAS HENRY MALLABAND formerly of 57 Fox Road Daniel Hill Walkley
Sheffield in the County of York now of 34 Nairn Street, Pathhead, Kirkcaldy, 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 to melting furnaces and it has for its object to improve
their construction. The invention is mainly designed for melting steel and iron.
One of the features of this invention is that there are two melting chambers, one
placed beside the other, and that the heat from the one is passed into the other, so
that it is used twice over before finally escaping by the chimney.
Another feature of my invention is that the melting can as desired be carried on
by either the coke and blast process or by gas.
And in order that my said invention may be properly understood, I have
hereunto appended two explanatory sheets of drawings, whereon:-
Fig. 1 is a part sectional plan view of the furnace, on the line a*-a*, Fig. 2 and
also showing the regenerators in section.
Fig. 2 is a vertical section on the line y.-z, Fig. 1.
Fig. 2 is a small detail view.
Fig. 3 shows in section a method of actuating the damper doors.
Fig. 4 is a cross section through a chamber I, Fig. 1.
Fig. 5 is a part longitudinal section on the line ** Fig. 1.
Referring to the drawings, whereon the same reference letters, wherever repeated,
indicate similar or like parts:-
The furnace consists of two melting chambers A, B, arranged one beside the
other as shown. These chambers are built up of suitable refractory material a and
are or may be enclosed in metal casings M. The furnace is built up in any
suitable and well known manner. The chambers have large removable covers M'
at top with central openings M³ in them as shown at Fig. 2. These covers when
removed allow of access being had to the interior of the chambers for repairing or
other purposes. Fitted on top of the covers M' and so as to cover the openings M*
are small covers N. When the covers N are removed, the chambers can be charged
with scrap, coke, etc., through the openings M. Round about the refractory
material is a space H, which is filled with sharp quick sand and which allows the
refractory material a, constituting the body of the chambers, to expand under
great heats.
The chamber A is made with a bridge or roof G in it, and through this bridge
there are a number of passages or channels G¹. The space F below the bridge G
forms a receiver for the molten metal, which can be drawn off through a passage F'
and delivery spout Q. A number of passages D which are made in the upper part
of the receiver lead to a re-heating flue E made under the bottom of the receiver F
and of the chamber B. C is a blast pipe or box, which is arranged around the
chamber A. Passages or twyeres C¹ lead from the blast pipe into the interior of
the chamber. P¹ is a sampling port or passage which leads into the receiver F.
A swivelling pipe or nozzle P, fitted to the underside of the blast pipe or box C,
may be arranged, so as to, if desired, deliver a blast down the sampling port into
the receiver. The pipe P can be closed at top by means of a sliding plate C². The
dotted lines, show the pipe P turned away from the furnace, so as to allow samples
to be taken out or the metal to be rabbled, through the passage P¹. The full lines
show the pipe as in position to deliver a blast down the passage Pl, into the
receiver. O is a crucible or melting pot which, when the furnace is heated by coke

page_text: and blast, is fitted in the roof or bridge G of the receiver F as shown. S is a
passage way which leads from the top of the chamber A into the chamber B. R is
another passage way from the bottom of the chamber B to the top of the receiver F.
D' are ports which communicate with the hot air flue E. The ports D and D'
allow any slag, which may rise, on the surface of the molten metal in the chamber B
and receiver F, to the level of the ports, to flow over into the hot air flue E, and,
as the flue E is on an incline, as shown, to run out of the furnace underneath the
spout Q. JJ, J, J, J, J', are passage ways, used when heating the chambers
with gas and air. I are regenerators which are built in the passage ways J', J',
J, Jas shown at Figs. 1, 4 and 5. The loose plates T underneath the furnace
are used for giving access to the bottom of the chambers A and B, so as to repair
them. U is a flue, which leads from the upper part of the chamber B to the main
chimney and it is provided with a regulating damper V. Fig. 24 shows a part
cross section through the flue U. K is the main flue to the chimney, and is shown
closed by a damper door L (see Fig. 1). K', K' are passage ways leading to the
main flue K.
Figs. 3 & 5 show the reversing valves or dampers b, c, g, f, used when the furnace
is being worked with gas, which are suspended by means of chains d¹ from
cross beams y suspended by means of a chain d from a pulley y whose axle y³ is
carried in brackets y. The chain d has, preferably, compensating or adjusting
links e on it. The valves of which there are two suspended from each beam, are,
as shown, so arranged that, when the chain is pulled down on one side, it opens
two of the valves and closes the other two and vice versa. i, j, k, l, are the valve
seats.
X is the gas inlet and X' is a screw down valve for controlling the gas supply.
As will be seen the sectioning below the chamber B, Fig. 2, is carried backwards
so as to show the passages J, J; and regenerators I. In reality these parts
should not appear in this fig. as they are at the back of the furnace (see Figs. 1
and 5).
The operation of the furnace is as follows:-
1. If the furnace is to be heated by coke and blast-The metal is placed in the
crucible or pot O, placed on the bridge or roof (t, and the fuel is heaped round
about it. The blast into the box C is then turned on and the crucible heated in
the same way as an ordinary cupola. The molten metal passes from the crucible
through the hole O' in its bottom down into the receiver I and can from thence be
drawn off for casting purposes. The products of combustion pass off from the
chamber A, by the passage way S into the chamber B and from thence by the
flue U to the chimney.
Scrap etc., may be heated or melted, if desired, in the chamber B, by the heat of
the waste gases from the chamber A. Any molten metal from the chamber B
passes by the passage R into the receiver F.
If desired a blow can be turned on to the metal in the receiver by means of the
pipe P.
When the furnace is being worked by coke and blast the passage ways J, J' are
closed.
2. If the furnace is to be heated on the regenerative gas principle-In this
case the blast to the box C is turned off, the passage ways J, Jare opened and
the flue U closed by the valve V. The crucible is removed and the bridge or
roof G is built up in its centre so that the scrap or pig iron can be charged upon it.
Any heavy metal to be melted is first charged into the chamber B and then
recharged into the chamber A. as the metal in said chamber runs away into the
receiver.
The gas valve X' is now opened and the valves b, c, g, f, are so operated as to
allow gas to pass from the pipe X (see Fig. 3) along the passage J'and regenerator
and then through the opening J into the chamber A. From the chamber A the
hot gasses pass, through the passage S, into the chamber B and heat up said
chamber finally passing back by the passages J and J' to the passage K' and main ·|

page_text: flue K. The air passes from the inlet at g along the passage J' and through the
regenerator to the chamber A and then, along with the gas, through the passage S
to the chamber B finally escaping through the passage Js to the passage K¹ and
main flue K. By turning the wheel y, the valves b, c, 9, f, can at any time be
reversed so as to allow gas to pass through the now open valve c, along and through
passage J* and its regenerator I to the passage J and chamber B and from this
chamber by the passage S, to the chamber A, finally escaping by the passages J, J³
and K to the main flue K. The air is reversed at the same time and passes through
valve, passages J, & J', chamber B, passage S, and escaping by passages J, J¹,
and K to the main flue K.
When heating the furnace with gas the molten metal, in the chamber A, runs
down through the openings G¹ into the receiver F into which also runs molten
metal, by the passage R, from the chamber B.
Air passing up the passage E is heated underneath the receiver F and under-
neath the bottom of the chamber B, also any hot gases escaping from the receiver F
by the ports D pass by said passage E to the second chamber B and their heat is
there again utilized.
The ports D, D¹ communicate with spaces E' made round the supporting
pillars E.
As will be seen, with my improved furnace, the melting process can, at the
option of the manufacturers, be carried on by either the coke and blast process or
by the regenerative gas process. Of course when the gas process is being used
the coke and blast process is not employed and likewise when the coke and blast
process is used the gas arrangement is shut off.
The running off of slag by the passage way E keeps the furnace and flues clean
throughout.
Instead of using one pulley y for suspending the valves, two pulleys can be used.
In this case no beams y, would be employed.
The brick roof or bridge G is made of very refractory material and when worn
out can be replaced by a duplicate one fitted up in segments.
This furnace is well adapted for general steel founders as they can melt at light
heats in quick succession.
The furnace, owing to its cylindrical form, is much cheaper to construct and
permits a more equal distribution of the expansion than furnaces as generally
constructed.
My improved furnace can be as easily repaired as an ordinary cupola.
When the furnace is heated by gas, Siemen's, Shiel's, or Wilson's gas producer
may be used.
The furnace can be altered in its details of construction without departing from
the principle of the invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what mauner the same is to be performed, I declare that what I
claim is :-
1. The general construction or combination of parts of the improved melting
furnace, substantially as hereinbefore described and shown on the drawings
annexed.
2. A melting furnace constructed so as to be heated either by coke and blast
or on the regenerative gas principle, substantially as hereinbefore set forth.
3. In melting furnaces a chain and pulley device for operating the reversing
valves b, c, g,f, substantially as herein before described and shown on the drawings
annexed.
Deted this 16th day of Tenu
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.