Improvements in Heating Stoves.
Year: 1898

page_text: COMPLETE SPECIFICATION.
Improvements in Heating Stoves.
I, FRANZ CHRISTOPH BORMANN, of 19, Steintwiete, Hamburg, in the German Empire,
Stove Manufacturer, 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 :—
Fire-stoves in which solid fuel is employed work most economically, as is well
known, when, for the purpose of increasing or reducing the production of heat,
the effective grate surface is correspondingly increased or decreased. In ordinary
furnaces the heating effect can be varied by sliding a plate in or out over the grate
bars so as to leave free only so much of the grate surface as is necessary to produce
the desired effect. The employment of such a plate is, however, attended with
practical difficulties and in ordinary'stoves, especially in slow combustion stoves,
is almost impossible. In ordinary stoves the production of heat is usually varied
by adjusting the air inlet slide, that is to say by increasing or reducing the area of
the air inlet openings. The great disadvantage of this arrangement is a
disproportionate consumption of fuel unless the abovementioned sliding plate on
the grate is employed. The improvements forming the subject of the present
invention obviate the disadvantages of the ordinary stoves. According to my
invention the entire surface of the stove grate is divided into several sections or
parts each of which has its own special air supply channel. When it is required to
increase or reduce the fire it is only necessary to open or close one or more of these
air supply channels, and the corresponding division or divisions of the grate surface
is or are brought into or put out of action. The effect of this opening or closing
of the air channels is exactly the same as if the corresponding parts of the grate
surface were covered or uncovered by a plate. The amount of opening of each
separate channel must naturally be left to the judgement of the person using the
stove.
The accompanying sheet of drawings illustrates, by way of example, a stove
constructed in accordance with the invention.
Figure 1 is a vertical section of the stove.
Figure 2 a plan of the slide for regulating the air inlet, and Figure 3 a section
taken on the line 3-3 of Figure 1..
a is an ordinary flat fire grate, which can be turned on its seat by means of the
lever b, and can be thereby shaken also for the removal of ashes. d, c are two
further fire grates which are produced by the formation of holes in the fuel chamber e.
In the stove shown the flame passes through the slot f into an annular channel g,
from which the gases pass into the gas drawing-off channel h. A conical
valve i, which can be raised and lowered by means of a crank handle, k serves to
open or close at pleasure the channel h. This conical valve i may be provided
with small holes for the escape of any carbonic oxide which may be formed in
the stove when the latter is closed up. This valve i does not form a feature of the
invention.
The air finds its way to the three divisions or sections of fire grate a, c, d,
downwards through the three channels m, n, o. The channel o is separated from
an annular channels by means of two vertical angle irons ? extending from the inner

page_text: fire-door p to the fixed slide face q, as shown in Figure 3. The annular channel 8
conducts air through small openings to the flame passing through the slot f into
the channel 9, as shown in Figure 1. On the plate lies a rotatable slide t
(Figures 1 and 2), which is provided with air inlet openings u for each
channel m, n, o. The plate q is provided with air inlet openings vu and x for
each channel n, m, o, 8. Some of the openings v admit air to the channels and
others to the channel o. The innermost holes z of the plate q serve to admit a
small quantity of air which passes downwards through the fuel in the fuel chamber.
A hand wheel a¹ serves for turning the slide t. The air can be admitted into the
cap 6, which covers the slide t, through a channel c¹, or through a suitable
opening.
In Figure 2 the slide t is shown turned back so far that it only puts the openings v
into communication with the outer circle of holes u. The openings vw, x and z are
covered on the left hand side of Figure 2 by the slide and are shown dotted
beneath it. In this position of the slide the air can pass through the flat grate a
and the channels o and 8. The grate surfaces c d and the openings z, which latter
form to a certain extent, a grate, are closed. When it is desired to increase the fire,
the slide t is turned further in the direction of the arrow e¹ (Figure 2) until the
second circle of holes u stands over the openings w.
The air can now pass to the fuel through v and w and consequently through both
grates a and c; by turning the slide t still further the two grates d and z can be
brought successively into action.
In order to extinguish the fire, or to reduce the heating effect, it is only necessary
to turn the slide in the direction opposite to that indicated by the arrow e¹.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what I
claim is:-
A slow combustion stove the fuel chamber of which is provided with one or more
fire-grates, such as c, d, besides the ordinary movable fire grate a, and in which
the said fire-grates a, c, d receive their supply of air through separate
channels m, n, o, provided with a regulating slide so arranged and constructed that
the said channels can be opened and closed thereby in succession substantially as
described.
11
2 T
1000