OR IMPROVED FURNACE AND APPARATUS FOR ANNEALING CASTINGS AND FOR DRYING AND HEATING CASTING MOULDS.
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Benjamin Joseph Barnard Mills
at the Office of the Commissioners of Patents on the 21st July 1883.
Communicated to him from abroad by Georg Fischer, of Hainfeld in the
Empire of Austria
BENJAMIN JOSEPH BARNARD MILLS of the firm of Harris and Mills of
23 Southampton Buildings in the County of Middlesex, Patent Agent A. NEW OR
IMPROVED FURNACE AND APPARATUS FOR ANNEALING CASTINGS AND FOR DRYING
AND HEATING CASTING MOULDS. A communication to me from abroad by Georg
Fischer, of Hainfeld in the Empire of Austria
The object of the present invention is a new furnace for annealing cast-steel
goods as well as for drying, heating and reheating the casting-moulds; this furnace
consists of several furnace chambers disposed one above the other in a slanting
position in the form of inclined galleries; into these furnace-chambers are introduced
vessels mounted upon wheels and having a cylindrical or some other form suitable
to the form of the chambers. These vessels contain the cast-steel goods that are
to be annealed.
Beneath the lowest furnace-chamber in about the middle of its length is placed
the main fire-place for heating the furnace and the said vessels. The furnace-
chambers communicate with each other by means of heat-distributing flues but in
order to obtain a still more uniform distribution of the heat in the upper furnace-
chambers, smaller fire-places are arranged beneath the bottom of each chamber.
The charging of the furnace is effected from its upper end, for which purpose the
said vessels are raised by means of a hoist of any desired forin. The discharging
of the annealed cast steel goods is effected at the lower end of the furnace chamber,
where for this purpose is arranged some device serving to discharge the vessels
regularly one after the other. Instead of each discharged vessel a new one can
be introduced at the charging mouth and thus a continuous uninterrupted working
of the furnace can be obtained. Each vessel having from the moment of its
entering the furnace till the moment of its discharge a rolling movement along the
bottom of the chamber, a prejudicial crystallization of the cast-steel goods in the

page_text: vessels, which occurs when the goods are annealed in horizontal furnaces, is entirely
avoided.
the
The Invention may be carried-into effect in the following manner.―
The furnace consists of three chambers arranged one above the other
bottoms of these chambers which are placed in an inclined plane; bear the rail-
track for the vessels and their upper part consists of hollow cylinders made of some
refractory material. Beneath the middle part of the lower furnace-chamber
forming the annealing chamber, is placed a fire-place by means of which both the
vessels and the furnace itself are heated; the smoke and the gases, produced by the
combustion of the fuel, are drawn out by a flue. The space in front of the
aforesaid fire-place can be employed as a storing place for the fuel. The
vessels containing the cast-steel goods are raised by means of
hoist of any
desired form, to the charging mouth, which can be shut by a plate made of some
refractory material. The smoke and gases emanating from the top of the chamber
at the moment when the plate is withdrawn for charging the chamber, are let out
from the space occupied by the hoist through a flue communicating therewith.
.
The vessels are then hoisted up to the mouth of the chamber and either simply
rolled down or let down by means of the hoist. The front part of the chamber
near the discharging mouth having a lower temperature than the rest of the
chamber, it is evidently preferable to charge the chamber firstly with vessels
containing smaller and finer cast-steel goods and to leave the heavier and larger
goods for a subsequent charging.
The vessels containing the annealed goods are discharged by a door at the lower
end of said annealing chamber. In order to effect the regular discharge a
contrivance is arranged near the outlet end of the chamber, by means of which only
one vessel at a time is let out by the door, whilst the rest of them are retained in
the chamber. As soon as one vessel is discharged a new one can be hoisted up
and introduced into the chamber by the inlet door.
..
In order to enable the flames and heat to circulate freely all around the vessels,
the chambers one above the other are so constructed as to leave a sufficient space
between the vessels and the walls of the chamber; for this purpose the bottoms of
the chambers between the rails are hollowed out.
For utilizing as much as possible the heat developed, the two upper chambers
serving for heating and drying the casting-moulds, are arranged immediately above
the annealing-chamber.
The chamber next above the annealing chamber is provided with a separate fire-
place by means of which it can be heated, in case the annealing chamber is not
heated at all or does not give sufficient heat; the top part of said chamber is
perforated with conduits by means of which the flames and heat are conducted
into the uppermost chamber. The smoke and gases are drawn out through a-flue
at or near the upper end thereof.
The two upper chambers are charged from a pit at the upper ends thereof
through inlet-mouths, which can be shut by doors. The discharging is effected
at the lower-outlet ends of the chambers which are also provided. with doors.
The vessels destined for annealing small cast-steel goods consist of hollow
cylinders made of metal or some refractory material and provided with covers the
projecting rim of which covers serve at the same time as flanges for the rails.
The cylindrical vessels can have either a smooth surface, or an undulated one, in
order to augment the heated surface.
The cast-steel objects, which on account of their larger size cannot be introduced
into the cylindrical vessels, are placed in trucks made of the best refractory material
and provided with a lid. or cover. The bearings of the trucks rest upon axles,
which are made in single piece with the wheels. In order to diminish the friction
of the axles, bearings can be provided with a lubricating-chamber, into which,
instead of grease, graphite, soap-stone or some other suitable lubricating substance
is introduced.

page_text: The moulds that are to be dried or reheated are introduced in the upper furnace-
chambers upon trucks bearing a platform and provided in front with wheels and
behind with sledge-runners. The objects that are to be introduced in the upper
chambers are placed in layers upon these platforms and if necessary, made fast by
means of cramps; the rapidity of the rolling down of these combined trucks is
regulated by placing the main weight of the charge oither in the front part over
the wheels, or behind over the runners.