IMPROVEMENTS IN AND RELATING TO FURNACES KNOWN AS CRUCIBLE FURNACES
Year: 1879

page_text: LETTERS PATENT to William Phillips Thompson, of the Firm of W. P.
Thompson and Co., Solicitors of Patents, of 6, Lord Street, Liverpool, in the
County of Lancaster, and 323, High Holborn, in the County of Middlesex,
Consulting Engineer, for the Invention of "IMPROVEMENTS IN AND RELATING
TO FURNACES KNOWN AS CRUCIBLE FURNACES." A communication from abroad
by Georg Fischer, of Hainfeld, in the Empire of Austria, Cast-Steel-Maker.
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 4th June 1879.
WILLIAM PHILLIPS THOMPSON, of the Firm of W. P. Thompson and Co., Solicitors
of Patents, of 6, Lord Street, Liverpool, in the County of Lancaster, and 323, High
"IMPROVEMENTS IN
Holborn, in the County of Middlesex, Consulting Engineer.
A communication
AND RELATING TO FURNACES KNOWN AS 'CRUCIBLE FURNACES."
from abroad by Georg Fischer, of Hainfeld, in the Empire of Austria, Cast-Steel-
Maker.
2 39
My new crucible furnace is made of three parts separable from each other,
namely:-The upper part or top cap, the middle part or melting room, and the
lower part or the air chamber with the melting plate.
The upper part consists of a dome shaped cap of sheet metal and of the top
funnel for feeding fuel. The middle part or melting room is provided with two
hollow axles turning freely in bearings arranged on pillow blocks supported by the
upper floor of the smelting house. It consists of a strong sheet cylinder lined
inside with any suitable refractory material. The said hollow axles allow of the
melting process to be observed and watched; they lie in a line of the centre of
Gutter-
gravity of the middle part, so as to facilitate the tilting of the same.
shaped tuyeres are arranged on the inside of the refractory lining in such a way
that they occupy the whole height of the same; each tuyere is divided by a small
diaphragm into two equal lengths, the lower one of which serves as a blast pipe to
lead the blast of air through holes into the interior of the melting room, whilst the
upper length is reserved for the time when the lower half of the melting room is
worn out and the middle part becomes necessary to be tilted or turned.

page_text: The lower part of my crucible furnace carries the crucibles and the fuel. It is
made to be raised by means of an elevator of any convenient construction, so as to
be united with the middle part of the furnace, or it may be let down upon a track
arranged on the floor of the smelting house, and moved on to the foundry or where
it may be required.
It consists of an air chamber which is divided by a wind sieve or air distributor
consisting of two, three, or more sector plates, in an upper and a lower part, which
latter communicates with the blast conduit pipes of a revolving fan or other
blowing machine. The air chamber is covered by a melting plate composed of two,
three, or more sectors of a circle and perforated with holes of requisite number, so
as to ensure as far as possible thorough and complete combustion of the fuel
without excess of air beyond that chemically requisite to furnish the necessary
equivalent of oxygen, and according to the number of crucibles to be placed in the
furnace. Upon the outer edge of the melting plate is fixed a jacket of strong
sheet metal which surrounds the lower half of the middle part of the furnace when
the air chamber is raised and connected with the melting chamber, thereby
preventing radiation of the heat. This jacket is also useful to catch and collect
the fuel rolling down on lowering the air chamber with the crucibles and fuel
thereupon, and to prevent the crucibles from falling during their transport on the
track. The air chamber is supported by two, three, or four track wheels or rollers
so spaced as to correspond with the gauge of the track rails. The outer diameter
of the air chamber is somewhat sinaller than that of the melting chamber, so that
an annular space is formed on the downward side of the melting plate from which
heat is free to radiate during the melting process, whereby the temperature of the
melting plate is maintained at a relatively low degree.
To regulate the pressure of the wind in the air chamber I employ a wind-
regulator which consists of a prismatic tube, preferably made of glass, which is
divided diagonally into two parts by a hinged blade loaded with an adjustable
weight. The blast having the desired force does not lift this loaded blade but
takes its way into the air chamber, but as soon as the blast current becomes too
powerful the loaded blade is lifted and air escapes under the same until the force of
the blast corresponds to the position of the said adjustable weight.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Phillips Thompson in the Great Seal Patent Office on the
4th December 1879.
WILLIAM PHILLIPS THOMPSON, of the Firm of W. P. Thompson and Co., Solicitors
of Patents, of 6, Lord Street, Liverpool, in the County of Lancaster, and 323, High
Holborn, in the County of Middlesex, Consulting Engineer. "IMPROVEMENTS IN
AND RELATING TO FURNACES KNOWN AS CRUCIBLE FURNACES.' A communication
from abroad by Georg Fischer, of Hainfeld, in the Empire of Austria, Cast Steel
Maker.
33
My new crucible furnace, if compared with other furnaces of this description
affords, in the first instance, the chief advantage of an easy and economic continuous
working, as its peculiar arrangement allows the lower part of the furnace containing
the crucibles and fuel to be raised by means of an elevator of any convenient
construction, so as to be put in connection with the middle part of the furnace, or
it may be let down upon a track arranged on the floor of the melting house and
moved on to the foundry or elsewhere, and may be replaced by another lower
part previously heated and charged with crucibles, which is then raised by the said
elevator and connected with the middle part as long as the latter is still in a highly
heated state. Another advantage of great importance is afforded by the arrange-
ment of the middle part or melting chamber of my furnaco, which is made to be
tilted on its horizontal axle. This may be done during the furnace, being in a
highly heated state, the tuyores being so arranged that the blast passes only through
their lower halves, their upper halves being reserved for the time when the tilting
becomes necessary. The accompanying Drawings are intended to form part of this
Specification and to illustrate the practical mode of carrying the Invention into
effect; but I do not limit myself to the precise forms and details shown as they
may be varied without departing from the nature of my Invention.
Fig. 1 is a side view of my crucible furnace with its lower part let down on the
track; Fig. 2 is a sectional elevation of the same through the line u, u, in Fig. 1;
Fig. 3 shows the same sectional elevation, but with the lower part being raised and
connected with the middle part of the furnace; Fig. 4 is a horizontal sectional
view through the line x, x, in Fig. 2, exhibiting the arrangement of the tuyeres;
Fig. 5 is a plan view of the melting plate on a larger scale; Fig. 6 is the wind
sieve; Fig. 7 represents a tuyere on a larger scale; Figs. 8 and 9 show the blast
conduit-pipes and the blast controlling apparatus. A is the middle part or melting
chamber of the furnace; it is suspended by two hollow axles a, a¹, turning freely
in bearings on two pillow blocks 6, 61, arranged upon the floor of the upper story
of the melting room; B is the upper part or cap with its top funnel c; C is the
lower part of the furnace consisting of the air chainber d, the melting plate m, the
wind sieve 8, and the jacket e; D, D', are two posts of iron or steel suitably
connected by cross-rails; they rise from the bottom of the melting room, passing
through the ceiling up to the requisite height, and form, together with the shaft E,
the pinions F, F, the handwheel G, the toothed racks H, H¹, the table or platform I,
the pulleys J, J, and the counter weight K, the elevator.
The melting chamber A is made of a strong sheet iron cylinder lined inside with
any refractory material ƒ which is clasped by angle iron rings g, gl. The hollow
axles a, a, lie in opposite directions to each other, and in a horizontal line of
gravity of the middle part A to facilitate the tilting of the latter. The tuyeres h, h, h,
are gutter-shaped and arranged inside the lining of the melting chamber A in such
a manner that the spaces between them are as large as the outer diameter of the
same or nearly so. They occupy the whole length of the melting chamber A.
Each tuyere is divided by a small partition, wall, or diaphragm i into two equal
lengths or halves, the lower one of which serving at each time as a tuyere or blast
pipe, whilst the upper half is kept in reserve. The tuyeres are perforated with

page_text: conveniently shaped holes k, k, through which the air passes into the melting
chamber. The axles a, a, are made hollow to allow the melting process to be
observed and watched through them.
The upper part B consists of a dome shaped cap of sheet metal and of the top
funnel c; on the tilting of the melting chamber the cap must previously be taken
off, and after, the tilting put on again.
The lower part C of the furnace is made to be raised by means of the elevator,
and is thereby connected with the melting chamber; or it may be lowered or let
down upon the track M, M¹, arranged on the bottom. The crucibles are placed on
stands upon the melting plate m covering the air chamber d. The said melting
plate is composed of two, three, or more sectors of a circle, and is perforated with
as many holes as are necessary to ensure, as far as possible, thorough and complete
combustion of the fuel without excess of air beyond that chemically requisite to
furnish the necessary equivalent of oxygen, and according to the number of
crucibles to be placed into the furnace. The arrangement shown in Fig. 5 will do
for a number of 22 crucibles. Through the melting plate m passes the central
tuyere n, also provided with side holes, and serving as a stand to the central
crucible, which may be placed somewhat higher than the others, which are arranged
in concentric series upon small stands and spaced so as to provide room enough for
the requisite fuel. The said jacket e fixed at the outer edge of the melting plate m
surrounds the lower part of the melting chamber (Fig. 3), protecting the same
against loss of heat, catching and collecting the fuel gliding down on lowering the
air chamber with the crucibles and fuel thereupon, and preventing the crucibles from
falling or upsetting during their transport on the track. Besides the jacket serves
as a fulcrum to the lever used to discharge the crucibles.
The jacket e, the melting plate m, with the whole charge are supported by the
air chamber d. This consists of a sheet cylinder closed at the bottom and provided
preferably with four small rollers or wheels q, q, and lined inside with refractory
material. The outer diameter of the air chamber is a little smaller than that of
the melting chamber, so that an annular space of the melting plate romains free,
from which heat may radiate to keep the melting plate at as low a temperature as
possible.
The air chamber is divided by a wind sieve s into a lower and an upper chamber.
This wind sieve is composed of two or more sectors perforated with holes to
regulate the distribution of the wind. The air enters the air chamber through two
short air feeding pipes t, t, cut obliquely and provided with flanges to facilitate the
connection with the blast conduit pipes. The air passes through the perforations
of the wind sieve and melting plate, and through the tuyeres h, h, and n, into the
interior of the melting chamber.
To regulate the wind pressure I employ an automatic wind controlling device of
a very simple construction, which is shown in Fig. 8 in a plan or top view, and in
Fig. 9 in a side view. It is made of a prismatic tube L open at the ends, preferably
made of glass, the interior of which is divided diagonally by a hinged plate v into
two parts, so that the blast entering at wis prevented by the said hinged plate v
from escaping at x if it is too weak to raise the latter together with the adjustable
load y. The hinged plate is provided with a graduation so as to allow the weight y
.to be shifted or adjusted according to the requisite wind pressure. The wind
pressure augmenting from whatever a cause the hinged plate will soon be raised so
that the blast becomes free to escape at x, and thereby the pressure in the conduit
pipe is kept as equable as possible.
The elevator for raising and lowering the crucibles is composed of two vertical
posts D, D¹, of iron or steel, serving as guides to the moveable platform I. On
turning the hand wheel G the said platform I carrying the lower part of the furnace
with the crucibles is raised or lowered by means of the pinions F, FL, and the
toothed racks H, H. K is a counterweight to facilitate and secure the motion; it
is fixed on one end of a chain or rope which passes over a pulley J; the other end
of this rope or chain is fastened to a rod connected at Q to the platform I. To

page_text: stop the up or downwards movement of the platform a brake or locking mechanism
of suitable construction or a ratchet wheel and pawl may be arranged on the
circumference of the hand wheel or on the shaft E.
It is evident that the just described elevator may even as well be replaced by a
hydraulic or any other elevator worked by any suitable prime mover without
departing from the substance of my Invention. N is a device to fix the air chamber
in its upper position, so that the platform may be lowered and let down upon the
track, whilst the air chamber is held firmly connected with the melting room of the
furnace. A track M, M', is arranged upon the bottom of the foundry, and passes
through between the posts D, D¹, of the elevator; from one end of this track the
loaded air-chambers are carried to the furnace, and the molten material is then
conveyed from the furnace to the other end of the track.
Having now described this Invention in the exact words as communicated to me
by my foreign correspondent, the same being the best mode known to him of
carrying the said Invention into effect, I wish it to be understood that what I
believe to be new and desire to claim under the hereinbefore in part recited Letters
Patent is,
1. A crucible furnace consisting of three parts, the upper one of which being
made to be taken off, the middle one being suspended and turning freely on hollow
axles, and the lower one being made so as to be raised or lowered, and also moved
on horizontally upon the floor of the melting house, all constructed substantially as
described and shown.
2. In a crucible furnace the arrangement of the tuyeres, the lower halves of
which only serve as blast-pipes, whilst there upper halves are reserved for the time
when the melting chamber becomes necessary to be tilted.
3. In a crucible furnace a melting or grate plate with an outer annular edge from
which the beat is free to radiate, whereby the melting plate is kept at comparatively
a low temperature, substantially as shown.
4. The automatic wind regulator consisting of a prismatic tube and a hinged and
loader plate, substantially as described and shown.
In witness whereof, I, the said William Phillips Thompson, have hereunto set
my hand and seal, this Third day of December, in the year of our Lord
1879.
W. P. THOMPSON. (L.S.)