IMPROVEMENTS IN FURNACES
Year: 1883

page_text: 4
PROVISIONAL SPECIFICATION left by William Edward Gedge at the Office
of the Commissioners of Patents on the 23rd February 1883. A Communi-
cation to him from abroad by Laurent, Auguste, Perrin, Builder, and Jean,
Eugène Alfred Servel, Doctor of Medicine, both chez Mr Delorme, St Etienne,
Loire, France,
WILLIAM EDWARD GEDGE, of N° 11 Wellington Street, Strand, London, in the
County of Middlesex, Patent Agent, "IMPROVEMENTS IN FURNACES" A Commu-
nication to me from abroad by Laurent, Auguste, Perrin, Builder, and Jean,
Eugène Alfred Servel, Doctor of Medicine, both chez Mr Delorme, St Etienne, Loire,
France;
This invention relates to an economical furnace for elevated temperatures.
The furnace of this invention is applicable in every case where an elevated
temperature must be economically produced, for all apparatus whether large or
small, gas retorts, boilers etc.
Its perfection results essentially from three principal objects or apparatus, which
may be used separately, but which give more complete results by their simultaneous
action.
These three objects are:-
1°. A loader or Feeder to feed the fire place with coal and nascent gasses.
2°. A hot air chamber utilizing the lost heat, without prejudice to the useful heat,
to the profit of the air intended for combustion.
3°. A system of hermetical and indestructable closers or fastenings which complete
the insulation already produced by the masonry and particularly by the dry
sand which we preferably use.
I will now summarily describe each of these apparatus, premising that the
general arrangement of the furnace is naturally and as usual a mass of brickwork
or masonry in the middle of which is the receiver to be heated.
The Loader or Feeder-This apparatus is composed of a cavity in the form of a
truncated cone, with vertical axis, the sides of which are of a refractory substance.
This cavity is open at its two ends, one the upper being smaller, the other the
2. 3.

page_text: lower being larger. The upper opening opens and closes at pleasure, exteriorly, by
means of a hermetical lid or cover; the lower opening remains wide open above the
fire place, at a sufficient distance from the grate. One or several orifices are formed
in the upper part of the feeder for introduction of air, coming either from the hot
air chamber or from the exterior.
Assuming the fire-place incandescent and filled from the grate to the base of the
feeder one
or more mandrels or stoke-bars are introduced into the apparatus
according to its dimensions, and they are sent down to the fire-bars of the grate,
then damp coal is poured in until it reaches the top of the feeder; in a few
moments the stoke-bars are withdrawn leaving at the desired spot an empty space
right through the mass of fuel.
This empty space opens the way for the penetration of air through the coal, in
the selected spot, for better combustion in the fire place; it permits the combustion
and the distillation of the coal throughout the course traveled by the air; so that
nascent gases arrive abundantly in the fire place to burn there, without smoke, and
with all possible intensity; further by the aid of this vacant space, the coal leaves
the sides of the feeder more readily, and thus obeys, without restraint the laws of
gravity.
This feeder thus arranged and filled has the further advantage of avoiding,
during an average of six hours, the ordinary work of the firemen.
Hot air Chamber-This part of the furnace should be included in the spot most
favorable to the utilization of the waste heat-In gas furnaces, having one or
several retorts, for example, we utilize the whole of the lower part of the furnace,
which constitutes a vast chamber traversed longitudinally by the chimney divided
into branches or flues; these branches afterwards re-uniting to rejoin the terminal
shaft.
To strengthen the furnace, this hot air chamber may be divided, by partitions,
into compartments communicating with each other
Air enters from the exterior by the part of the chamber which is lowest and
furthest from the fire place; it issues on the contrary by the part which is highest
and nearest to the fire place. The inlet, or outer, orifices are small, the exit orifices
are very large.
The air which passes through this chamber therefore takes a great part of the
heat which would be lost and acquires an elevated temperature; but another
advantage is added to this under the combined influence of the feeder and the
hermetical closings, the volume and the tension of the air increase in proportion to
its temperature, and the result is an effect of ventilation the cause of which is as
follows:-1° The air cannot easily pass through the thickness of coal contained in
the fire place when the feeder is charged-2° It is also impossible for the air to
escape by the doors, either of the fire place, the ash pit, or of the feeder, as they
close hermetically-3° Finally the air cannot easily flow back towards the inlet
orifice of the chamber, of which this orifice occupies the lowest part. By these
arrangements the hot air therefore acquires a tension or ventilation force which
increases with its temperature, and the measure of which is given by the distance
to which it is possible to attain, for example a lighted candle placed above the open
feeder.
Hermetic closings-These parts of the furnace are constituted essentially by
amianthus or asbestos joints upon rough cast iron ("foute Crute") on the one side
fif a door and its frame are in question) a large fluting receives the amianthus; on
the other a small fluting is incrusted or let into the joint and determines or effects
a complete occlusion. To increase the duration of these fastenings we add to the
doors wedge shaped latches and screw hinges.
These amianthus joints on rough cast iron are applicable in every case where the
joints are exposed to heat, such as the closing of retorts etc
Such are the three objects or apparatus which constitute the combined elements
of improvement in the construction and working of furnaces; elements which

page_text: permit them to work regularly during a relatively considerable lapse of time
without firemen, nor mechanical motor; to realise savings of fuel and to be enabled
to produce the most elevated temperatures.
It will be understood that to these special objects or apparatus are added all the
apparatuses indispensable to ordinary furnaces that is to say a grating, a water
trough, a fire bridge, a good draught, dampers etc, then the other accessary parts
corresponding to the particular adaptation of the furnace.