Improvements in Furnaces.
Year: 1899

page_text: Date of Application, 31st Jan., 1899--Accepted, 11th Mar., 1899
COMPLETE SPECIFICATION.
Improvements in Furnaces.
I, DAVID TOWNSEND, of No. 1723, Wallace Street, in the City and County of
Philadelphia, State of Pennsylvania, United States of America, Mechanical
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:-
My invention relates to improvements in furnaces in which producer gas, or
products of combustion from an ordinary fire chamber may be used. The object
of my invention is to so construct the furnace that the gases after passing from the
producer or fire chamber will be mixed with hot air, and combustion will imme-
diately take place in a chamber especially provided for the purpose, adjacent to
and communicating with or forming part of the heating chamber of the furnace.
I will describe my invention with reference to the accompanying drawings of
which Figure 1 is a longitudinal vertical section of a furnace constructed according
to my invention the furnace shewn being what is known as a metallurgical heating
furnace.
Figure 2, is a horizontal section on the line 2-2, Figure 1;
Figure 3, is a vertical section on the line 3-3, Figure 1;
Figure 4, is a perspective view of one of the air ducts detached;
Figure 5, is a perspective view of one of the bricks forming inclined passages
over the air ducts.
Figure 6 is an enlarged view of part of Figure 1.
Figure 7 shews the invention as applied to an ordinary steel melting furnace.
Figure 8 is a longitudinal vertical section of a boiler furnace shewing my inven-
tion applied thereto and Figure 9 is a transverse sectional view showing my
invention applied to a retort furnace.
Referring to Figures 1 and 2, A is the gas producer chamber having a grate a
for supporting the fuel and under which is the ash pit A¹ with which communi-
cates an air blast pipe a', having a steam pipe a provided with a regulating
valve is the feed opening for the coal in the crown of the chamber A the
said opening being provided with a hopper A², the details of which will be herein-
after described.
B is the metal heating chamber having the usual bed & supported on a suitable
framework B beneath which is a space or chamber C, in which the air used in
producing the proper combustion can be pre-heated. D is the combustion chamber
hetween which and the chamber B is a bridge wall d of any suitable height. The
gas from the producing chamber A passes by a passage D and through other
passages to the combustion chamber D the transverse passages being formed
by air ducts E which rest on suitable arches e.
The air ducts E communicate with passages c in the side walls of the furnace
and these passages connect in turn with the pre-heating chamber C, under the
bed of the furnace. This space or chamber C receives air through two passages c¹
from two heating chambers C on each side of the flue B2 at the rear of the furnace

page_text: and air is supplied to these chambers C¹ through the pipes C³, having a suitable
regulating valve ct. The chambers C protect the brickwork of the chimney
stack from the intense heat of the furnace.
The air that passes through the pipes C2, heating chambers C and passages c
leading to the ducts E is heated so that it will readily mingle with the gases as
they pass through the passages .
Forming a partition between the combustion chamber 1) and the air and gas passages
is a series of notched or perforated bricks I, clearly shewn in Figure 5, which when
assembled form passages i and these passages which are arranged in pairs are
inclined at such an angle to a vertical line between them that one passage of the
pair will communicate with the air ducts E and the other with the gas passages d',
and as the air and gas passes through these openings each in a thin sheet, they will
cross each other and become thoroughly mixed and the combustion will take place
at once in the chamber D. The combustion will be completed in the chamber D
and the heated products will pass into the heating chamber B in the best possible
condition for heating or melting the metals contained therein.
In some instances when it is desired to use the ordinary grate fire I may either
build the furnace especially for this purpose, or may keep a fire on the grate,
raking it in the same manner as an ordinary furnace fire, and the products of
combustion from the coal will pass up through the passage D' and passages d' and
mix with the air in the combustion chamber D, so that thorough combustion will
take place in the chamber D.
The partition I instead of being formed of a series of small sectional bricks may
be made by uniting a series of long sections or may be made from a single slab,
but I prefer the construction shown in the drawings.
It will be understood that the main features of my invention may be embodied
in the ordinary metal melting furnace, as shown in Figure 7, by forming narrow
elongated slots arranged at an angle, one or more slots being connected with the
gas chamber and the other slot or slots connected with the air chamber, so that
the gas and air as they pass from their chambers into a combustion chamber will
cross each other in thin films and be thoroughly mixed and ignited in the combus-
tion chamber before entering the melting chamber.
The hopper A2 Figure 1 is provided with a valve 9 connected to a weighted
lever g by a link g, and the lever g' is pivoted at h to a projection on the casing
of the hopper against which fits a sliding cover plate n having a socket adapted
to receive the projection of the casing, and in order to confine this socket to the
casing, a spring is provided which tends to keep the socket tightly against
the projection on the casing and prevent leakage of gas at the joint. A weight g³
on the lever g' can be adjusted so that the valve will dump automatically as soon
as a certain amount of coal is placed within the hopper and as soon as the coal is
dumped the valve will return to its seat.
The hopper is provided with a suitable cover which is sealed to prevent
leakage of gas.
Opposite the grate a is an opening as provided with a suitable door a so that
a slicer bar can be inserted above the grate to either cut the ash when the cham-
ber A is used as a gas producer, or to prepare the bed of coal when the chamber
is used as a fire chamber.
By adjusting the air valve and the steam valve the flame in the furnace
can be so regulated as to give the best possible result. On checking the steam
an excess of air is obtained and the product is an oxidizing flame, whereas a
reducing flame is obtained by checking the air.
It will therefore be seen that I can use either the gas from a producer, or the
partly consumed products of combustion from an ordinary furnace, and thoroughly
mix the same with a given quantity of hot air, and burn the mixture in a chamber
before it enters the heating chamber of the 'metallurgical furnace.
In Figure 8 I have shown my invention in connection with an ordinary

page_text: Doller B. The ducts E are mounted on arches e and spaced so as to form pas-
sages, and the bricks I, having the inclined notches ii are mounted upon the
ducts in the manner herein before described. Gas is produced in the chamber A³
and the combustion thereof is completed in the chamber D³, directly under the
boiler. Care hot air tubes communicating with the air supply pipe C³ and
through the passages C¹ with the 'ducts E. Other well known forms of boilers
may be substituted for the boiler 133 shown.
In Figure 9, I have shown a small retort furnace in which the ducts E are not
supported by arches across the chamber A3; B are transverse retorts and Cris
the hot air supply pipe/situated in the flue of the furnace.
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:-
1. In a furnace, the combination of a series of air ducts situated adjacent to the
combustion chamber, and bricks adapted by notches and projections or the like to
engage with the air ducts, the said bricks being arranged in series alternately
across the ducts, and across the spaces between the ducts, so as to form air and
gas passages, respectively, substantially as described.
2. The combination in a metallurgical furnace, of the gas producing chamber A
having the grate a, a space beneath the grate, a blast pipe communicating with
the space, a hopper in the upper portion of the gas producing chamber, a passage D¹
for the gases generated in the chamber A, transverse air ducts spaced to form
passages communicating with the passage D¹ perforated partition above the
air ducts and the gas passages, some of the perforations in the partition com-
municating with the air ducts while others communicate with the gas passages, a
combustion chamber D above the perforated partition, a heating chamber B beyond
the combustion chamber and with which the said combustion chamber com-
municates, a chimney stack, air passages in the stack and under the bed of the
heating chamber, the said air passages communicating with the air ducts, substan-
tially as described.
3. The combination with the gas producer or furnace A, of a hopper, a valve
therein, a weighted lever connected to the valve and pivotted to the hopper, a
projection on the hopper, a lever having a cap resting against the projection and
longitudinally movable on the lever, and a spring tending to keep the cap on the
projection, substantially as described.
4. In a furnace, the combination of a gas producing chamber, a grate therefor,
a space under the grate, an air blast pipe communicating with the space under
the grate, a combustion chamber, a series of air ducts having spaces between them
and situated between the gas producing chamber and the combustion. chamber,
perforated bricks above the air ducts and spaces, some of the perforations com-
municating with the air ducts and some with the spaces, so that a mixture of air
and gas is introduced into the combustion chamber, and means for heating the air
prior to its entering the air ducts, substantially as hereinbefore described.
5. In a furnace, the combination of a gas producing chamber, a combustion
chamber, a series of arches having spaces between them and arranged between the
gas producing chamber and the combustion chamber, an air duct in each arch,
an air passage at the side of the furnace communicating with the air duets, and a
perforated partition carried by the air ducts, some of the perforations communi-
cating with the air ducts and others with the gas chamber, substantially as herein-
before described.
6. In a furnace, the combination of a gas producing chamber, a combustion
chamber, a heating chamber communicating with the combustion chamber and
with the chimney stack, an air pre-heating chamber under the bed of the heating
chamber, air passages in the side walls of the furnace communicating with the
pre-heating chamber, a series of arches having spaces between them and arranged.
between the gas producing chamber and the combustion chamber, and air ducts

page_text: on the arches suitably spaced for the passage of gas to the combustion chamber
and communicating with the air passages in the side walls of the furnace, sub-
stantially as described.
7. The improvements in furnaces as herein described and illustrated in the
on the arches suitably spaced for the passage of gas to the combustion chamber
and communicating with the air passages in the side walls of the furnace, sub-
stantially as described.
7. The improvements in furnaces as herein described and illustrated in the
accompanying drawings.
Dotal 1 07th day of Tonuo 1800
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C.,
Agents.