Improvements in Slow-combustion Stoves.
Year: 1899

page_text: Date of Application, 22nd Dec., 1899-Accepted, 8th Dec., 1900
COMPLETE SPECIFICATION.
Improvements in Slow-combustion Stoves.
I, FRANZ CHRISTOPH BORMANN, Steintwiete 19, Hamburg, Germany, 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:-
This invention relates to a continuous combustion stove in which the area of
heating surface is regulated by alteration of the draught.
The object of the invention is to provide a stove in which the heat radiating
surface may be increased or diminished as desired, in a quick and efficient manner.
In the accompanying drawings, the same reference letters indicate correspond-
ing parts in all the figures,
Fig. 1 being a longitudinal section and
Fig. 2 a cross section taken on the line X-X of Fig. 1 showing one method
of carrying out my invention.
Fig. 3 is a section of a modified form of the upper part of the stove and
Fig. 4 a plan of same.
Fig. 5 is a plan view representing the regulator plate K on the right hand
partly in section and the disc b on the left hand.
In ne form of stove illustrated in the accompanying drawings a base plate
provided with an upwardly extending flange supports a cylindrical casing g.
This casing g is closed at its top by a cover.
A short cylinder of small diameter is suspended in the lower part of the
cylinder g and is closed at its upper end by a flanged plate which extends from
the back of the cylinder across the casing g to the front thereof and forms
the bottom of the ash box. A cylinder g³ of smaller diameter than the cylinder g*
is disposed therein and is supported at its upper end from the flanged plate at
the top of the cylinder g. This cylinder g³ constitutes a flue and is connected with
a pipe leading to a chimney, not shown. A damper i, preferably cone-shaped, is
adapted to close the mouth of the cylinder g³. This damper has perforations
therein which permit the passage of the gases of combustion therethrough with-
out creating a draft. As shown, this damper is connected at its apex to a vertical
rod. This rod connects with a horizontal rod which extends through the walls
of the cylinders g g and g and is provided on its outer end with a crank handle k
by means of which the damper i is operated.
A fire box is supported in the casing g above the ash box. This fire box is
provided with a grate a and a door a'.
The ash box is provided at the front thereof with a door which may be provided
with a damper for regulating the entrance of the air to the fire box. In the
drawing a removable pan shown disposed in the ash box below the grate for
receiving the ashes and which may be inserted and withdrawn through the
door.
A dome e is disposed above the fire-box and extends to the top of the casing g.
This dome is preferably reduced at its upper end and a flanged cover fits over
said reduced end and closes it tightly. The dome e is provided throughout its

page_text: length with a series of groups of perforations c, d, and 2, to admit air. For
each of these groups of perforations flue openings g¹ are provided. The various
groups of perforations and their respective flue openings divide the dome e into
a number of zones each of which can be thrown into and out of action quite inde-
pendently of the others.
Channels are formed between the cylinder g and the dome e, into which the
Hlues glopen. These channels h¹ extend the full length of the stove and serve
to convey the gases of combustion to the pipe h which leads to the chimney.
The outer surface of the cylinder 9 constitutes the heating surface of the stove
and the amount of heat radiated therefrom may be regulated by throwing into or out
of action one or more of the groups of perforations c, d, d¹, 2. For each of these
group of perforations c, d, d, z there is a vertical channel c, d, d³, z¹ each of
which opens out under the regulator plate k. This regulator plate k has open-
ings m, m', m², m³, of various sizes (see right hand side of Figure 5) and over
the same a second rotatable disc b with perforations n, n¹, n², n³ is so arranged
that by rotating the latter the entrance of air through the perforations n, n', n³, n³
into the vertical channels c¹ d³ ³ 2 can be regulated or cut off for one group,
several or all.
When all of the groups of air-inlet holes are open the flames and exhausted
gases of combustion are drawn up the full height of the dome and pass out
through the flues g' into the channels h¹ and pass in a downward direction, as
indicated by the arrows, around the cylinder into the cylinder g³ and out
through the pipe h. To decrease the heating surface one or more of the
groups c, d, d, z may be closed by rotating the disc b in the. direction of the
arrow (Fig. 5) by means of a handle o, whereby the draught causes the flames to
pass out through the flue next adjacent thereto in a downward direction into the
channels and that part of the cylinder above the open group is rendered in-
active and is only slightly heated. The heating effect may be further decreased
by shutting off all of the groups c, d d', z as shown in Fig. 5. In this case the
flames and products of combustion pass directly from the fire box in the direction
of the arrows in a downward direction out through the pipe h, whereby only the
lower part of the stove is strongly heated and the amount of heat radiated there-
from is consequently very much decreased.
The closing of the damper also serves to reduce the heating effect by shutting
off the draught and permitting the smoke to pass out through the perforations
therein.
P
In the construction shown in Figs. 3 and 4, besides the usual rotatable air-
regulator the air entering from the room through the holes q and in the top
of the stove can be further throttled, before passing through into the
channels c¹.
This is effected by covering the holes of the disc b with a movable disc y,
having pointed openings and slots p.
By means of the handle o the pointed openings r can be suddenly opened, and
the slots are simultaneously caused to correspond with the slots q, and a full
entrance of air is permitted. On further rotating the disc. y, the pointed ends
of rover the openings reduce the passage of the air according to the decrease in
their size.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what
claim is
1. In a stove, the combination of a fire box, a heating shaft disposed thereover,
and having perforations therein, a casing surrounding said shaft and forming a
channel between them, and means for closing a portion of said perforations
whereby the heat radiating surface is diminished.
2. The combination of a fire-box, a shaft disposed thereover and provided with
a series of groups of perforations, independent flue openings for each of said

page_text: groups, and means for opening and closing the groups of perforations whereby
the heat radiated therefrom can be regulated.
3. The combination of a fire-box, a dome-shaped shaft disposed thereover, said .
shaft having groups of perforations therein, flue openings for each of said groups,
through which the fire heats downwardly, and a damper for closing said openings.
4. The combination of a fire-box, a dome having groups of perforations therein,
means for admitting air to said openings, flue openings for each of said groups,
means for closing the perforations of one group independently of the other, and
channels connected with said flues for conveying the products of combustion to a
place of exit.
5. In a stove, the combination of a fire-box, a.. shaft disposed thereover and
provided with groups of air admission holes, flues connected with said opening?
for carrying off exhausted gases; means for closing said air admission holes and
means for regulating the entrance of air into the top of the stove.
Dated this 3rd day of August 1900.
JOHNSONS,
Applicants Agents, 115, St. Vincent Street, Glasgow.