Improvements in Slow Combustion Grates, Furnaces, or Stoves.
Year: 1897

page_text: Date of Application, 5th Apr., 1897-Accepted, 22nd May,
1897
COMPLETE SPECIFICATION.
Improvements in Slow Combustion Grates, Furnaces, or Stoves.
I, AUGUST PAMPUS, of Nos. 13-17 Fleethörnstrasse, Kiel, in the German
Empire, 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 slow combustion grates or furnaces, in which the supply
of air is mainly introduced from one or more sides. In such combustion apparatus
as usually constructed, the air can escape without passing through the glowing
fuel on the grate. In consequence the air is not mixed thoroughly with the gases
of combustion and the resulting considerable excess of air causes incomplete
combustion.
This invention has for its object the provision of means whereby the air,
introduced at the side of the fuel is forced to pass under all circumstances through
the glowing fuel on the grate, before such air can escape into the exit flue of the
gases of combustion.
In order that my invention may be the better understood, I now proceed to
describe the same with reference to the accompanying drawings and to the letters
and figures marked thereon.
The drawings illustrate the invention as applied to a boiler furnace, but it may
be used for stoves and heating apparatus of any kind.
Figure 1 shows a vertical section through a furnace constructed according to my
invention, and
Figure 2 shows a vertical section through a modification thereof.
The fuel is fed through the orifice a on to the grate c and forms there two
layers b d. The first layer b which lies direct on the grate c is always glowing and
forms the support of the newly fed fuel d. The lower layer b which, by the
evolution of gases, is converted into coke, causes the evolution of gases from the
upper layer of fuel d. The fuel receives a supply of air through the side channels f
of a wall f. In the construction shown in Figure 1, an obliquely rising wall w is
provided opposite to the wall f. The wall w has steps w¹ whereby, a passage is
formed between the fuel and the wall for the air entering below the grate, which
therefore finds admission to the fuel also at the side opposite to the wall f.
Below the wall fis provided a fire proof projecting corner g which extends into
the fuel, and which is preferably formed by a metallic tube cooled by water. This
projecting corner g forces the air admitted at the side of the layer of fuel to pass
through the fuel d under all circumstances. In this manner the air is thoroughly
mixed with the evolved gases of combustion and this mixture of gas and air is also
compelled to pass through the layer of glowing fuel b lieing on the lower grate c,
before the air passes into the exit flue h; in consequence combustion is as complete
as possible. If the projecting edge is formed by metallic tube cooled by water,
the tube may be used as feed water heater or connected direct to the boiler.
The action is as follows:-
The air enters from below to the grate c and simultaneously between the steps w
of the brick or stone wall w and the fuel, in order to pass into the layers b and d.
Besides, air is admitted from the closable opening o in order to pass into the fuel
from the other side. The air admitted between the steps wand the fuel is
compelled by the draft of the chimney to pass through the fuel to the exit h,

page_text: whereby it is intimately mixed with the gases evolved, and the air entering through
the channels is compelled by the corner g projecting into the fuel to pass through
the glowing fuel on the grate and to mix thoroughly with the gases evolved from
the upper layer of fuel, before it can escape into the exit flue.
By the position of the projecting edge the object to prevent the air entering
through the channels f¹ from passing direct to the exit place h, and to force it to
enter and pass through both the layers of the fuel d and b first, is attained with great
certainty. In consequence the utilization of the fuel is complete.
1
In the modification shown in Figure 2 the air entering through the channels f¹
at the side of the fuel is forced by the projecting fire proof corner in a similar
manner to pass through the glowing fuel before it can escape into the exit
flue h.
This modification differs from the construction described with reference to
Figure 1 inasmuch as the side of the oblique brick or stone wall w which is turned
towards the fuel is smooth without steps. In this case the fuel will lie close to the
wall so that little or no air can enter from below.
Any suitable grate may be used but it is preferably constructed so that it can
be easily cleaned, and that the fuel can be easily extinguished in case of
danger.
For this purpose the grate, as shown in Figures 1 and 2 is guided vertically
in two side walls, so that it may be raised and lowered through parallel planes.
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 I
claim is:-
1st. A furnace for slow combustion apparatus in which air is introduced to the
fuel by surrounding channels at its sides, having a fireproof corner g, projecting
into the fuel and adapted to force the air to pass through the glowing fuel b nearest
to the grate under any circumstances in order to mix thoroughly with the gases of
combustion and thus to obtain complete combustion.
2nd. A construction of the furnace claimed in Claim 1, in which the fire proof
corner g, projecting into the fuel is formed by a water tube.
3rd. A furnace as claimed in Claim 1 having an obliquely rising wall w,
provided with steps w', against which the fuel may rest, so that a passage is made
between the fuel and the wall w.
4th. A construction of the furnace claimed in Claim 3 in which one side is
superseded by a smooth obliquely rising wall w, so that the air can enter only
through the channels f¹ of the wall fat the side of the fuel.
Dated this 5th day of April 1897.
FELL & JAMES,
Agents for the Applicant.