Year: 1894

page_text: Date of Application, 6th Nov., 1894-Accepted, 8th Dec., 1894 -
Empire of Austria.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E. of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street
Manchester, both in the County of Lancaster and High Holborn in the County
of Middlesex, Civil Engineer, 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 has for its object an improved muffle furnace which admits of a
convenient and economical working and which has also the particular advantage
that the goods to be burnt, whether large or small, may be exposed to the action of
the fire with equal security without fear of any cracking or breaking of the said
goods.
In the accompanying drawings-
Figure 1 is an isometrical view partly in section of the improved muffle
furnace;
Figures 2 to 4 are cross sections of the same on the lines x x, y y, zz of
Figure 1;
Figure 5 shows a pan or tray.
The muffle furnace A in plan is of a U-shaped form, and contains the muffle B.
This latter in its central parts, that is to say where it is exposed to the greatest
heat, consists of fireclay plates, whilst the two rectangular branches B₁ B" are
made of iron plates to allow of an easy or rapid heating or cooling owing to their
being good conductors of heat. a b c are partitions for the firing introduced into
the chamber G, the partitions a c extending up to the roof of the furnace and the
partition 6 to the upper edge of the muffle passage. The heated gases rise between
the walls a and b, pass at d over the muffle, flow round this latter at e, reunite in
the passage (Figure 3) rise at g (Fig. 1) again upwards, and finally after again
flowing over the muffle passage at h escape through the flues i into the smoke
chamber which is provided with a regulating damper or slide (Figure 4).
Whilst in the continuous working muffle furnaces hitherto employed the so-called
"drawing muffle" of the main heated chainber was shut off from the warming and
cooling muffles, and consequently by reason of the sudden alteration of temperature,
breakages of the goods, more particularly in the case of large articles, took place,
in this improved muffle furnace the heating passage E F is interrupted by no
partitions. The pans or trays, Figure 5, which are inserted at C and pushed
forward on the rails m gradually reach the hottest part of the muffle over the firing
chamber G and become constantly hotter. The cooling down also takes place
equally gradually up to the exit D so that even in the case of large articles no
breakage or cracking need be feared. The pans or trays (Figure 5) consist of a
frame R of sheet metal, the bottom of which is formed of three iron bars n rivetted
to this frame, and coated with fireclay or earthenware plates n'. These iron bars n
are arranged at such distances apart that when the pans are pushed forward, they
slide on the rails m. By this mode of construction, the pans are both lighter in
weight and also of greater durability than those hitherto employed, which were
constructed entirely of iron or of fireclay and were either very heavy or very easily.
broken.
.
If after a long period of working of the furnace the cooling chamber should

page_text: become too hot, or if it be desirable to accelerate the cooling process, air may be
allowed to enter the passages op, which air flows round the muffle, cooling the
latter and warming itself, and it may then be conducted to the furnace in order to
utilise the heat absorbed.
The fire place of this furnace is constructed in the following manner-At 1,
Figure 2, the fuel is inserted, at 2 the grate is attended to, and the slag and ashes
removed. This arrangement has for its object to enable the fuel to be brought
already warmed to the grate for combustion.
3, 4, and 5 are air passages which convey underneath the grate heated air from
the cooling chamber B". The air nozzles or openings 6, 7, 8, 9, are also connected
with the cooling chamber Bч, and convey very heated air to the flames developed,
so that the last remnants of unconsumed carbon are entirely consumed, so that a
smokeless combustion takes place and the fuel is. utilised to its fullest extent.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is--
1. An improved muffle furnace having its warming and cooling chambers B¹ B"
formed of iron plates and directly connected (without intermediate partitions) at
right angles to the main heating chamber B formed of fireclay plates and an
arrangement by means of partitions a bc, whereby the heated gases are caused to
rise between a and b, flow at d over the muffle B, pass round the latter at e, re-unite
in the passage f and again rise at g in order once more to flow over the muffle
passage ath and finally be carried off through the orifices i into the smoke
chamber k substantially as described and illustrated.
2. In the improved muffle furnace described in Claim 1, the arrangement of air
passages 3, 4 and 5 which convey under the grate heated air from the cooling
chamber B and the arrangement of air nozzles or passages 6, 7, 8, 9 which also
convey heated air from the cooling chamber B into the furnace gases and
so produce a complete combustion of the fuel substantially as described and
illustrated.
3. In the improved muffle furnace described in Claim 1, the arrangement of pans
(Figure 5) consisting of a frame R of sheet metal, the bottom of which is formed of
three bars of iron n with fireclay or earthenware plates n' and attached by rivets to
the sheet metal plate and adapted to slide on rails m substantially as described and
illustrated.
Dated this 5th day of November 1894.
WM. P. THOMPSON & Co.,
Agents.