An Improved Muffle Furnace for General Heating and Annealing Purposes.
Year: 1898

page_text: Date of Application, 8th Dec., 1898-Accepted, 4th Feb., 1899
COMPLETE SPECIFICATION.
An Improved Muffle Furnace for General Heating and Annealing
Purposes.
I, WILLIAM GEORGE MOORE, of Old Buildings, Lower Temple Street, in the
City of Birmingham, 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 relates to furnaces or muffle-furnaces for heating and annealing
purposes generally, and consists in an improved construction of furnace which has
for its principal object to obtain a more uniform and constant heat in the annealing
chamber with economy of fuel.
The furnace according to this invention is characterised by a heating or anneal-
ing chamber or oven, into which the substances under treatment are placed, open
only at one end, and which is surrounded on its sides by longitudinal fire or com-
bustion flues, at its top by a crown flue leading from the tops of the said fire or
combustion flues, at its ends by down flues which lead from the crown flues, and
at its bottom by longitudinal under-flues into which the said down-flues lead and
discharge; the said under-flues being connected with an outlet passage in com-
munication with a chimney or stack. The annealing or heating chamber is
therefore wholly surrounded by, or nestled within, a combination of flues through
which the whole of the heat products from the fire or combustion flues pass and
give up their heat, so that when they leave the under-flues their useful heating
properties have been practically exhausted.
in
In the accompanying sheet of drawings a furnace or muffle-furnace according
to this invention is shown in transverse vertical section in Fig. 1, in longitudinal
vertical section in Fig. 2, and in horizontal section in Figs. and 4 the last
named figs. being respectively taken upon the dotted lines A and B Fig. 2. In
these figs. c is the oven or muffle which is situate in the centre of the body of the
furnace and which extends for nearly the whole of the length of the furnace, the
said oven or muffle constituting the heating or annealing chamber into which the
substances to be treated are placed. This oven or muffle is closed at its back c²,
bottom 3, and crown by suitably built walls, and is open at its front end
the ordinary manner; the crown taking the form of the usual arch. The said
oven is so disposed in the body brickwork a² of the furnace a as to be completely
surrounded by a number of flues or passages through which heated gases pass on
their way to the chimney or stack, the said oven at its sides being bounded by
longitudinal fire or combustion flues a, a, (extending the whole of the sides of
the oven) at its crown by an arched flue, a³, leading from said fire flues, at its ends
by vertical flues, d, d, and at its bottom by longitudinal under-flues g g², the said
vertical flues d, 2, being in communication with the arched flue, , through
passages,, and leading to the under flues g, and the said flues being con-
nected with the flues g by passages g' which lead to a chimney or stack.
In the drawings the combustion flues a³, at, are shown fitted with fire bars h
which extend the full length of the flue and from end to end of the furnace, so that

page_text: the fire covers or abounds the full length of the heating or annealing chamber;
this being clearly shown by Figs. 3 and 4.
The products from the combustion chamber play freely upwardly the full length
and depth of the said chamber and over the arch or crown of the heating or
annealing chamber on both sides, and then pass forwardly and rearwardly over
the surface of the said arch and through the passages d³, d, in the end walls to
the vertical flues d, d, at the extreme back and front of the annealing chamber,
from whence they pass to each of the under-flues y situate under the bottom i of the
oven; the products from the flue d taking a direct vertical course to the said
flues g, and the products from the flue taking an arched or circuitous course
to the said flue g, in order to clear and pass round the oven's open end.
If necessary the passage g³ between the underflues g, g², may be fitted with a
damper as also may be the passages d³, d, in order to concentrate the heat more
to the front or back end of the oven as may be desired.
The arch of the oven c is preferably built up of segmental arches, m², formed
of 4 fire bricks, which are separated by thin slabs m³ of refractory material,
so that the heat can better obtain access to the oven from its crown covering than
would be the case if the arch was formed of 4" brickwork.
The arch of the heating or annealing chamber may, if desired, have openings
formed within it, through which the heated gases from the combustion chamber
may pass into the interior of the said annealing chamber, and from thence to the
end passages through the vertical flues. This form of arch would be desirable
in the case of treating substances of a high fusing point or which require intense
heat.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
First. A muffle furnace, characterised by combustion flues a³, a', disposed each
side the heating or annealing chamber c, so as to extend its full length and lead
upwardly, an arched flue a leading from the tops of the said combustion flues to
the centre of the oven's arch, and vertical end flues d, d2, in communication with
said arch flue, substantially as described and set forth.
Second. A muffle furnace whose heating or annealing chamber c is surrounded
on its sides by combustion flues or chambers a³, a, at its crown by an arched
flue a³, at its ends by vertical end flues d, d, at its bottom by underflues g, g2 ;
all in communication with each other substantially as described and set forth.
Third. The particular construction and arrangement of muffle furnace, sub-
stantially as set forth in Figs. 1 to 4.
Dated this 7th ow of Dasom han 1000
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also of Liverpool, London and Manchester,
Patent Agents for the Applicant.