IMPROVEMENTS IN GAS HEATED FURNACES SUCH AS ARE USED IN THE MANUFACTURE OF ZINC (SPELTER).
Year: 1882

page_text: LETTERS PATENT to Charles Madge of Swansea in the County of Glamorgan
for an Invention of "IMPROVEMENTS IN GAS HEATED FURNACES SUCH AS
ARE USED IN THE MANUFACTURE OF ZINC (SPELTER)."
PROVISIONAL SPECIFICATION left by the said Charles Madge at the
Office of the Commissioners of Patents on the 19th October 1882.
CHARLES MADGE of Swansea in the County of Glamorgan "IMPROVEMENTS
IN GAS HEATED FURNACES SUCH AS ARE USED IN THE MANUFACTURE OF ZINC
(SPELTER)"
This invention relates to gas heated furnaces such as are used in the manufacture
of zinc (Spelter).
The improvements have for their object to produce a more uniform heat in the
furnace and to increase the length of the smelting campaign thereby effecting great
economy in the cost of repairs.
The furnace whether on the Belgian or Silesian system may be constructed in
the usual manner except in the parts to which the improvements are applied.
These are arranged and constructed in the following manner.
In the gas heated regenerative furnace the air and gas are as heretofore supplied
to the bottom of the regenerator chambers by means of channels or culverts
running below the whole length or breadth of same numerous slits or openings
being formed through the floor of the regenerators for the passage of air and gas
from the regenerators the gas and air pass into the furnace through flues in their
roof and across the furnace and down through corresponding flues regenerators
and slits to the culverts and thence to the stack. The action being reversed at
intervals in the usual manner by means of valves.
It is found that the air and gas instead of passing uniformly to all parts of the
furnace have a tendency to take the shortest way to the stack and so the furnace
becomes unevenly heated.
To remedy this tendency I divide the culverts or channels which are below the
regenerators into two parts by means of a horizontal brick partition running the
whole or part only of their length-if for the whole length then suitable openings
(one or more) have to be provided in same for passage of air and gases.

page_text: The supply of air and gases entering through the culvert becomes divided-
that passing into or out through the upper half supplying or taking, from the end
of the regenerator and furnace nearest to entrance and exit end of the furnace
the lower division supplying or taking from the opposite ends and centre of
regenerators and furnace.
The volume of air and gases passing into or out of the upper or lower half of
the Culverts can be easily regulated by partially closing the openings in the
partitions or of the entrances into the upper or lower divisions of the culverts
and so become uniformly distributed over the whole length or breadth of the
furnace.
At the present time the duration of a campaign or one continuous working of n
Spelter gas furnace is limited by the formation of slag in the furnace and by the
slag blocking up the inlets for gas and air from the regenerators into the furnace.
This I remedy in the following manner.
The air and gases are as heretofore supplied to and taken from the furnace in
the usual manner by means of vertical flues or channels leading from the roof of
the regenerators and opening horizontally into two parallel horizontal culverts or
flues which pass side by side under the bed of the furnace from one end of it to
the other These culverts are covered by bricks or brick arches on which the
retorts or muffles rest or by the retorts or muffles. themselves so arranged as to
leave openings between each brick or brick arch or retort through which the air
and gas enter or the gases pass out of the furnace.
One of the horizontal parallel flues hins gas supplied to it from one regenerator
chamber and the other has air supplied to it from another regenerator chamber.
The partition between the two parallel flues prevents the premature mixing and
combustion of gas and air.
The slag formed by the action of heat on the furnace and retorts and their
contents passes into these flues or culverts and as the heat in these flues or culverts
is not sufficient to enable it to be flowed or skimmed out therefrom it accumulates.
until the flues become choked and the furnace campaign terminated-the furnace
must then be let out cleaned and repaired--To remedy this I make provision for
increasing the heat in the two horizontal parallel culverts so as to liquify the
collection of slag whenever it becomes necessary until the slag flows into suitable
beds prepared for it and so the campaign is prolonged and costs of repairs greatly
reduced.
For this purpose I arrange or construct in the partitions which separate the one
culvert from the other one or more (preferably 5 or 6) openings and also
corresponding openings in the outside walls of the furnace-Ordinarily whilst the
furnace is at work all these openings are temporally closed with bricks and luted
with clay.
When the slag has accumulated sufficiently in the horizontally parallel culverts
these bricks are taken out and only those in outside wall of the furnace
replaced.
The gas and air entering from the regenerators mixing and combustion taking
place. at a lower level in the culverts-Sufficient heat is then produced to render
the slag fluid and it flows into sand beds prepared in the spaces between the
culverts and outside walls of the furnace-the brick filling in the latter being
removed at intervals to enable the slag to be withdrawn-this is continued
until the culverts are cleared of the slag when the brick fillings can be
replaced.
In the same way the slag which sometimes lodges in the slits or openings
between the bricks or brick arches covering the culverts will also be cleared
away.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Madge in the Great Seal Patent Office on the 19th April
1883.
CHARLES MADGE of Swansea in the County of Glamorgan
"IMPROVEMENTS
IN GAS HEATED FURNACES SUCH AS ARE USED IN THE MANUFACTURE OF ZINC
(SPELTER)"
This Invention relates to gas heated furnaces such as are used in the manufacture
of zinc (spelter).
The improvements have for their object to produce a more uniform heat in the
furnace and to increase the length of the smelting campaign thereby effecting great
economy in the cost of repairs.
The furnace whether on the Bélgian or Silesian system. may be constructed in
the usual manner except in the parts to which the improvements are applied.
The improvements are shewn in the drawing hereunto annexed.
Figure 1 is a transverse vertical section of the furnace one half taken on the
line A B the other on the line C. D. Figure 2 is a longitudinal vertical section
one portion on the line E. F. G. H the other on the line E. F. J. K. H.-Figure 3-is
a horizontal section one part on the line O. P. the other on the line M. N.
In these Figures A. A. are the regenerator chambers each filled with brickwork
piled in the ordinary way so as to leave passages between the bricks.
Air and gas are as heretofore supplied to the bottom of the regenerator chambers
by means of channels or culverts a running below the whole length or breadth of
same numerous slits or openings b being formed through the floor of the
regenerators for the passage of air and gas. Gas is supplied through one of the
culverts and air through the other culvert at one side of the furnace. From the
regenerators the gas and air pass' into the furnace through flues c in their roof and
across the furnace and down through corresponding flues regenerators and slits to
the other pair of culverts and thence to the stack. The action being reversed at
intervals in the usual manner by means of valves.
It is found that the air and gas instead of passing uniformly to all parts of the
furnace have a tendency to take the shortest way to the stack and so the furnace
becomes unevenly heated.
To remedy this tendency. I divide each of the culverts or channels which are
below the regenerators into two parts by means of a horizontal brick partition d
running the whole or part only of their length.-if for the whole length then
suitable openings (one or more) have to be provided in same for passage of air and
gases.
The stream of air or gas passing through each culvert being so divided, that
portion which passes into or out through the upper half will supply or take from
the end of the regenerator and furnace nearest to the entrance and exit end of the
furnace and the lower division will supply or take from the opposite ends and centre
of the regenerators and furnace.
The volume of air and gases passing into or out of the upper or lower half of
the culverts can be easily regulated by partially closing the openings in the
partitions or of the entrances into the upper or lower divisions of the culverts
and so become uniformly distributed over the whole length or breadth of the
furnace.
The next part of my invention relates to increasing the length of the smelting
campaign.
At the present time the duration of a campaign or one continuous working of a
spelter gas furnace is limited by the formation of slag in the furnace and by the
slag blocking up the inlets for gas and air from the regenerators into the furnace
This I remedy in the following manner and as is shewn in the drawing hereunto
annexed.

page_text: The air and gases are as heretofore supplied to and taken from the furnace in
the usual manner by means of vertical flues or channels c leading from the roof of
the regenerators and opening horizontally by passages g into two parallel horizontal
culverts or flues h which pass side by side under the bed of the furnace from one
end of it to the other.-These culverts are covered by bricks or brick arches on
which the retorts or muffles rest or by the retorts or muffles themselves so
arranged as to leave openings k between each brick or brick arch or retort
through which the mixed air and gas enter or the gases pass out of the furnace.
One of the horizontal parallel flues has gas supplied to it from one regenerator
chamber and the other has air supplied to it from another regenerator chamber.
The partition between the two parallel flues prevents the premature mixing and
combustion of gas and air.
The slag formed by the action of heat on the furnace and retorts and their
contents passes into these flues or culverts anil as the heat in these flues or culverts
is not sufficient to enable it to be flowed or skimmed out therefrom it accumulates.
until the flues become choked and with furnaces of the old construction the
furnace campaign would then be terminated-the furnace must be let out cleaned
and repaired. To remedy this I make provision for increasing the heat in the two
horizontal parallel culverts so as to liquify the collection of slag whenever it
becomes necessary until the slag flows into suitable beds prepared for it and so the
campaign is prolonged and costs of repairs greatly reduced.
i
For this purpose 1 arrange or construct in the partitions m which separate the
one culvert from the other one or more (preferably 5 or 6) openings n and also
corresponding openings n in the outside walls of the furnace. Ordinarily whilst
the furnace is at work all those openings are temporarily closed with bricks and
luted with clay.
When the slag has accumulated sufficiently in the horizontally parallel culverts
these bricks are taken out and only those in outside wall of the furnace
replaced.
The gas and air entering from the regenerators mixing and combustion taking
place at a lower level in the culverts.-Sufficient heat is then produced to render
the slag fluid and it flows into sand beds, prepared in the spaces o between the
culverts and outside walls of the furnace the brick filling in the latter being
removed at intervals to enable the slag to be withdrawn this is continued until
the culverts are cleared of the slag when the brick fillings can be replaced.
In the same way the slag which sometimes lodges in the slits or,openings
between the bricks or brick arches-covering the culverts will also be cleared away.
Having thus described the nature of my invention and the manner of
performing the same I would have it understood that I claim as my improvements
in gas heated furnaces such as are used in the manufacture of zinc (spelter).
First. The means for obtaining a more uniform distribution of air and gas to
all parts of the furnace substantially as herein before described.
Second. The means for enabling the heat to be at times increased in the
culverts to liquify slag necumulated therein and for running off the slag when so
liquified substantially as herein before described.
In witness whereof I the said Charles Madge have hereunto set my hand and
seal this fourteenth day of April in the year of our Lord One thousand
sialit hundred and eighty three.
CHAS. MADGE (L.S.)