Improvements in Furnaces for Heating and Melting.
Year: 1895

page_text: Date of Application, 13th Nov., 1895
Complete Specification Left, 13th Aug., 1896-Accepted, 28th Sept., 1896
PROVISIONAL SPECIFICATION.
-Improvements in Furnaces for Heating and Melting.
I, FRANCIS RADCLIFFE, of 233 Burrage Road, Plumstead, in the County of
Kent, Chief Foreman of Forges, do hereby declare the nature of this invention
to be as follows:-
In the Specifications of my previous Patents No. 15880 of the year 1884 and
No. 14416 of the year 1889 are described constructions of furnaces that may be
used for various purposes aud in which the hot gases and products of combustion
passing away from the melting chamber are utilized in a continuous manner to heat
air that is passing also in a practically continuous way to the melting chamber and
to the gas producers.
Now my present invention has reference to furnaces constructed on the principle
just alluded to. I now cause the hot gases after they have done duty in heating
air on its way to the melting chamber to pass along flues or passages entirely
surrounding the inner walls of the producers thereby aiding to maintain the
requisite temperature in the producers, and from the surrounding flue or passage
of each producer there is an independent exit leading to the common flue that
communicates with the chimney, and each exit is furnished with a suitable
damper whereby flow of spent gases around the producers may be completely
controlled.
The opening for the removal, insertion and cleaning of the fire bars formed in
each producer wall is arched over, and at a suitable distance below the arch there
is or are a bar or bars to support the outer ends of the fire-bars. If when the
apparatus is at work air be allowed to pass between the fire bars near their front
ends thus causing combustion beneath the arch and beyond the proper zone within
the producer, injury to its walls results: not only so, but ignition may be caused
of the gases within the producer. To obviate these evils I provide a plate adapted
to slide (in grooves in the walls of the producer) over the fire-bars, the arrangement
being such as to prevent air from entering the producer at the opening or between
the fire bars near their front ends, and preparatory to starting the producers I
olose up the openings between the said plates and the arches. A construction of
sliding plate for the purpose is made with a flange at its front end standing
upright, which closes the inner space from top to bottom. The plate covers the
fire bars as aforesaid and any opening not protected is to be filled with loam.
In order to as far as practicable protect those engaged in attending to the furnace
from inconvenience arising from the heat, I provide in a frame secured in the
brickwork of the producer two separate doors adapted to be opened and closed
independently of each other, the arrangement being such that the opening of the
upper door will give access to the fire bars, and the opening of the lower door will
afford access to the ash pit for the removal of the ashes ete.
A furnace according to my present invention suitable for glass melting has two
gas producers each constructed of firebrick with fuel feeding arrangement, closed
ash-pit, air-supply thereto, and the several improvements hereinabove referred to,
the arrangement being, of course, such that the producer gas and air, as also the
gases escaping from the melting chamber constantly pass in their respective initial
directions thus (as in furnaces according to my before mentioned earlier patents)
obviating the necessity of arrangements for reversing.

page_text: The apparatus for heating the air to be used in the producers and in the melting
chamber can be placed either above, below, at the sides, or at the end of the
melting chamber; usually preferring, however, to place the apparatus above the
melting chamber. The hot gases from the melting chamber pass through
the working chamber, thence to the air heating apparatus, which is a chamber (or
chambers) containing tubes made of refractory material and baving their ends
inserted into two walls which separate the air chamber (or chambers) from a couple
of boxes or spaces, one at either end or either side of the air heating chamber (or
cbambers). One of these boxes or spaces is supplied with air from a blower fan
or other means of producing a blast, which air is caused to pass through the tubes
to the other box or space. Each box or space is divided internally by a partition,
so that each gas producer as well as the melting chamber will have a supply of
heated air without the use of an additional regenerator such as shown in the
drawings accompanying the specifications of my former patents already mentioned.
Each compartment of one of the boxes or spaces is supplied with air from a blast
producer, between which and said compartments there are valves or other means
of regulating the air supply. Between the melting chamber aud the working
chamber, in lieu of the ordinary bridge 1 provide a partition wall that extends
from the bottom to the crown of the melting chamber and has through it one or
more of the usual passages or "dogholes on a level with the bottom of the
melting chamber. To conduct the hot gases from the melting chamber to the
working chamber the partition wall has formed in it a hole or holes or passage or
passages at a height or beights that will be sufficiently above the level of the
melted material. In that portion of the crown above the working chamber outlets
are provided whereby the products of combustion pass by a suitable fluc or flues to
the air heating apparatus, the said outlets being so arranged as to be as nearly as
practicable equally distant from the corresponding working holes, in order that the
distribution of heat around each working hole may be as nearly uniform as possible.
Although I have described the nature of my improved furnace as it may be
constructed with two gas producers it is to be noted that I do not limit myself to
that number.
1
27
For steel melting and other metallurgical processes, heating of retorts for the
production of gas for illuminating purposes, cement manufacture, enamelling,
cremation, refuse destruction, etc., the furunce may be modified by dispensing with
the working or second chamber, and providing for the flow of the spent gases
directly by a flue or flues to the air heating apparatus; or other modifications may
be made, to suit special applications.
Dated this 13th day of November 1895
..
Improvements in Furnaces for Heating and Melting.
1, FRANCIS RADCLIFFE, of 233 Burrage Road, Plumstead, in the County of
Kent, Chief Foreman of Forges, 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:
In the Specifications of my previous Patents No. 15880 of the year 1884 and
No. 14416 of the year 1889 are described constructions of furnaces that may be used
for various purposes and in which the hot gases and products of combustion passing
away from the melting chamber are utilised in a continuous manner to heat air

page_text: the gas producers.
Now my present invention has reference to furnaces constructed on the principle
just alluded to, as I shall now describe with reference to the accompanying
drawings wherein
Fig. 1 is a front elevation and Fig. 2 a longitudinal vertical section of a furnace
of the kind referred to embodying my present improvements.
Figs. 3 and 4 are horizontal sections on the lines A A and B B respectively
of Fig. 2, Fig. 4 showing only one half of the furnace.
Fig. 5 is a cross section on the lines C C of Fig. 2.
Fig. 6 is a rear end elevation of the furnace.
Figs. 7, 8 and 9 are detail views.
The furnace shown has two gas producers 1, 1" each constructed of firebrick with
fuel feeding arrangement,.closed ash-pit 1b and air-supply passages 3 thereto, the
arrangement being, of course, such that the producer gas and air, entering the
melting chamber 2 by the ports 4 and 5 respectively as also the gases escaping
from the melting chamber, constantly pass in their respective initial directions,
thus (as in furnaces according to my before mentioned earlier patents).obviating
the necessity of arrangements for reversing. The arrows a and b in Fig. 2 indicate
the course of the air and products of combustion respectively.
In order to aid in maintaining the requisite temperature in the gas producers 1, 1ª,
1 cause the hot gases after they have done duty in heating air on its way to
the melting chamber 2, as hereinafter described, to pass from a flue 6 into
which they are delivered, along flues or passages 7 that surround the inner
walls of the gas producers 1, 1 and from each of which there is an independent
exit 7 leading to the common flue 7 that communicates with the chimney, each
exit being furnished with a suitable damper 7° whereby flow of spent gases around
the producers can be completely controlled.
The opening 8 for the removal, insertion, and cleaning of the fire-bars 9, formed
in each producer wall is arched over as shown moro clearly in Figs. 7 and 8,
which are vertical sections at right angles to each other of part of one of the
producers. If when the apparatus is at work, air be allowed to pass between
the fire bars 9 near their front ends, thus causing combustion beneath the arch
and beyond the proper zope within the producer, injury to its walls results i not
only so, but ignition may be caused of the gases within the producer. To obviate
these evils I provide over the outer ends of the fire-bars as far as the inside of the
arch of each producer, a plate 10 adapted to slide in grooves 1 in the walls of the
producer, and preparatory to starting the producer I close up the space between
the plate and the arch, the arrangement being such as to prevent air from entering
the producer at the opening 8 or between the fire bars 9 near their front ends.
Each opening 8 may conveniently be closed by an upwardly extending flanged
part 10 of the sliding plate 10, which is protected from burning by a fire-
brick 10° fitted thereto, any opening not protected being filled with loam.
In order to as far as practicable protect those engaged in attending to the
furnace from inconvenience arising from the heat, I provide in a frame 11 (Figs. 1
and 9) secured in the brickwork of each producer, two separate doors 12, 12"
adapted to be opened and closed independently of each other, the arrangement
being such that the opening of the upper door 12 will give access to the fire bars 9,
and the opening of the lower door 12 will afford access to the ash pit 1° for the
removal of the ashes etc.
The furnace shewn in Figs. 1 to 6 inclusive is suitable for use in the manufacture
of glass for which purpose it has in addition to the melting chamber 2 a working
chamber 2°.
The apparatus for heating the air to be used in the producers and in the melting
chamber, can be placed either above, below, at the sides, or at the end of the
melting chamber, I usually prefor, however, to place the apparatus above the
melting chamber 2, as in the example shewn. The hot gases from the melting

page_text: chamber 2 pass into the working chamber 2" and thence to the air heating apparatus,
whence they pass to the flue 6 leading to the flucs or passages 7 hereinbefore referred
to. The air heating apparatus comprises a chamber 13 divided, in the example
shewn, by a mid-partition 13 into two compartments containing tubes made of
refractory material. These tubes have their ends inserted into two walls 15, 15º
which separate the air heating chamber 13 (or chambers) from a couple of boxes
or spaces 16, 17, one at each end (or it may be at each side) of the air heating
chamber 13 (or chambers). The box 16 is divided internally by partitions 18 so as
to form two central compartments 16 and two. side compartments 16ª to each of
which air is supplied from a blower, fan or other means of producing a blast.
Between such air supply blower and each compartment there is or may be a valve
or other means of regulating the air supply. The compartments 16 are connected
with the box 17 by two inner groups of tubes 14 and the two outer compart-
ments 16 are connected to two similar outer compartments 17 by two outer groups
of tubes 14, so that each gas producer 1, 1ª, as well as the melting chamber 2, will
have a supply of heated air without the use of an additional regenerator such as
shown in the drawings accompanying the specifications of my former patents already
mentioned, the heated air passing from the box 17 to the air ports 5 and from the
boxes 17 to the two vertical air passages 3 (Fig. 2) leading to the ash pits of the
two producers.
"
Between the melting chamber 2 and the working chamber 2, in lieu of the
ordinary bridge I provide a partition wall 19 that extends from the bottom to the
crown of the melting chamber and has through it one or more (two are shown) of
the usual passages or "dogholes 20 on a level with the bottom of the melting
chamber 2. To conduct the hot gases from the melting chamber 2 to the working
chamber 2 the partition wall 19 has formed in it holes or passages 20ª (or there
may be only one such passage) at a height or heights sufficiently above the level of
the melted material. In that portion of the crown 2 that is above the working
chamber 2, there are provided outlets 20, (three are shown) whereby the products
of combustion pass by suitable flues 20%, or it may be by a single flue, to the top of
the chamber 13 of the air heating apparatus, the said outlets 20° being so arranged
as to be as nearly as practicable, equally distant from the corresponding working
holes 21, in order that the distribution of heat around each working hole may be as
nearly uniform as possible.
Although I have described the nature of my improved furnace as it may be
constructed with two gas producers, it is to be noted that do not limit myself to
that number.
For steel melting and other metallurgical processes; heating of retorts for the
production of gas for illuminating purposes, cement manufacture, enamelling,
cremation, refuse destruction, etc., the furnace may, as shown in longitudinal and
cross section in Figs. 10 and 11, be modified by dispensing with the working or
second chamber 2 (Figs. 1 to 6 inclusive), and providing for the flow of the spent
gases, directly from the chamber 1 by passages 20 and flue 20 to the right hand
end of the air beating apparatus. Other modifications may be made in the furnace
to suit special applications.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
hot
1. A beating and melting furnace of the kind herein referred to in which the
guses after they have done duty in heating air on its way to the heating or
melting chamber is caused to pass along flues or passages surrounding the inner
walls of the gas producers and from each of which flues or passages there is an
independent exit with damper leading to the common flue that communicates
with the chimney, substantially as herein described for the purposes specified.
2. A heating and melting furnace of the kind herein referred to in which each
gas producer is provided with a plate 10 adapted to slide over the fire-bars'in

page_text: grooves in the wall of the producer and below an arched over opening that is formed'
in the wall of the producer and which between the arch and the said plate is,.
preparatory to starting the producer, closed up air tight, the arrangement being
such as to prevent air entering the producer at the opening, or between the fire-
bars near their front ends, substantially as herein described for the purpose
specified.
3. A heating and melting furnace of the kind herein referred to constructed with.
an air heater comprising a chamber (or chambers) containing refractory tubes having
their ends fixed in two walls which separate the chamber (or chambers) from a
couple of boxes or spaces each of which is divided internally by partitions into main
and supplementary boxes or spaces, the main and supplementary boxes or spaces.
at one end being connected with a blower or other means of producing a blast, and
the main and supplementary boxes at the other end being connected respectively
with the melting chamber and with the closed ash pits of the gas producers used
for supplying combustible gas to the melting chamber, the arrangement being such
that a supply of heated air can be supplied to the said ash pits without the use of
an additional regenerator, substantially as horein described.
4. A heating and melting furnace of the kind herein referred to constructed with
melting and working chambers having between them a partition wall that extends.
from the bottom to the crown of the melting chamber and has through it one or
more passages or dogholes on a level with the bottom of the melting chamber for
passage of molten metal, and one or more gas and flame exit passages situate above
the level of the molten metal, the crown of the working chamber having outlets
arranged as nearly as practicable equally distant from the corresponding working
holes of the working chamber and in communication with the air heating apparatus,
substantially as described for the purpose specified.
5. My improved furnace for beating and melting, constructed, arranged and.
operating, substantially as herein before described with reference to and shown in
Figs. 1 to 9 inclusive, or modified according to Figs. 10 and 11, of the accompanying
drawings.