A CLOSED STOVE FURNACE
Year: 1884

page_text: I ANDERS BORCH RECK, 3 Turesensgade, Copenhagen, Denmark, Civil Engineer
do hereby declare the nature of said invention for A CLOSED STOVE FURNACE
to be as follows:-
This improvement has for its object to produce a close stove furnace, burning
all sorts of fuel, especially bituminous coal, with. the least possible loss. in its
heating effect.
This object is attained 1) by making the furnace of the stove large enough to
contain sufficient coal for five or more hours combustion without replenishing,
2) by making the height of the coal on the grate so large, that it can be divided
in several horizontal layers, each layer from 3 to 9 inches thick and 3) by pro-
viding a separate canal of air, surrounding each of these layers, the said canal
going all round in the wall of the furnace and giving the air admission from the
canal to the furnace through a continuos siit or through a larger number of holes
or slits, well protected against being choked up by the ashes. Each canal has
its own air valve, that regulates the flow of the air into the canal from outside
of stove.
The coal is lighted from above and burns down one horizontal layer after the
other, each layer being burnt by the air. from the canal surrounding it. When
a layer of coal is burnt, the air valve of the canal surrounding it can be closed,
so that no air goes through the furnace without having passed a layer of burning
coal.
As the fire is always on the surface of the coal, where the air is admitted,
no coal gas from the coal beneath the burning layer can escape without going up
through the burning coal, where it is mixed with air and burued..

page_text: COMPLETE SPECIFICATION.
I ANDERS BORCH RECK, Gothersgade 155, Copenhagen do hereby declare the
nature of said invention for A CLOSED STOVE FURNACE and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement :-
This improvement has for its object-to produce a close stove furnace, burning
all sorts of fuel, especially bituminous coal, with the least possible loss in its
heating effect.
This object is attained, 1) by making the furnace of the stove large enough to
contain sufficient coal for five or more hours combustion without replenishing,
2) by making the height of the coal on the grate so large, that it can be divided
in several horizontal layers, cach layer from 3 to 9 inch thick, and 3) by providing
a separate canal of air surrounding each of these layers, the said canal going all
round in the wall of the furnace, and giving the air admission from the canal to
the furnace, through a continuous slit or through a large number of holes or
slits, well protected against being choked up by the ashes. Each canal has
its own air valve, which regulates the flow of the air into the canal from outside
of stove.
The essential character of the apparatus is, that, after the coal has been lighted
from above, it burns down one horizontal layer after the other, each layer being
burnt by the air from the canal surrounding it. When a layer of coal is burnt,
the air-valve of the canal surrounding it can be closed, so that no air goes through
the furnace, without having passed a layer of burning coal.
As the fire is always on the surface of the coal, where the air is admitted, no
coalgas from the coal beneath the burning layer can escape, without going up
through the burning coal, where it is mixed with air, and burned.
This new furnace can be employed for closed stoves, intended for general heating
purposes, for hot air warming apparatus, for hot water boilers and all other similar
apparatus.
And in order that the said invention may be more clearly understood and readily
carried into effect, I will proceed, aided by the accompanying drawing, more fully
The drawing represents the application of this improvement to a cast iron
furnace, which may be employed in a stove, destined to heat a single or several
rooms at a time in a building.
Fig. 1 is a horizontal section through a-b-c in fig. 2.
Fig. 2 and fig. 3 are vertical sections through the lines d-e and f―g in fig. 1,
and fig. 4 is a front view of the furnace.
The interior space B of the furnace is filled with coal through the door n (fig. 3),
till the coal lies from the grate 1 (fig. 3) to the height of door n.
Through valves p¹, p2 and p³ on the front of the furnace (fig.. 3) can air,
necessary for maintaining the combustion of the coal, be admitted to the three

page_text: air canals p, which go all round the furnace. Each canal.lies between the outside
wall, t, of the furnace and a cylinder, r, resting on a rib, q, cast on the inside of
the wall t.
From the canals, p, the air goes into the interior of the furnace through the
slits, 8, along the upper edge of the cylinders, r. The slits, 8, are protected against
being choked up, on account of the upper edge of the cylinders, 7, being inclined
backwards.
The coal is lighted from above, by igniting a few pieces of wood laid on the
coal through the door, n, while air is admitted through the valve p¹.
When the uppermost layer of the coal is burnt, the valve pi is closed and
p opened. When the next layer is burned p is closed and p³ is opened, and to
complete the combustion of the last rest of the .coal, air is at last admitted under
the grate, l, through the valve pt. The grate is cleaned, and the ashes taken out
through the door m.
C is the outlet for the smoke, the heat of which can be utilized in different
manners.
The material for the furnace may be any other fire-proof material than cast iron,
the number of horizontal air-canals, p, may be any other then three, and the air
may be introduced from each canal into the fuel chamber through a number of
slits, one beside the other, instead of through a single continuous slit, as represented
in the drawing.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I would state, that
I do not confine myself to the precise details herein described or delineated, as
the same may be varied, without altering the characteristic nature of my invention,
but what I claim is
The construction of a furnace, in which the coal burns down one horizontal
layer after the other, each layer being burnt by the air from an air canal
surrounding it, and only the undermost layer being burnt by air, admitted
through a common grate, all in the manner substantially as described and as
illustrated.