IMPROVEMENTS IN KILNS FOR BURNING LINE
Year: 1872

page_text: LETTERS PATENT to Robert Young, Manager of the Lime Works,
Straiton, and William Walker Stephens, of Leith, both in the
County of Mid Lothian, Executor of Peter Brash, late of Leith,
Soap, Candle, and Oil Manufacturer, deceased, for the Invention of
"IMPROVEMENTS IN KILNS FOR BURNING LINE.”
Sealed the 31st January 1878, and dated the 24th September 1872.
PROVISIONAL SPECIFICATION left by the said Robert Young and
Peter Brash at the Office of the Commissioners of Patents, with
their Petition, on the 24th September 1872.
We, ROBERT YOUNG, Manager of the Lime Works, Straiton, and
PETER BRASH, of Leith, Soap, Candle, and Oil Manufacturer, both in
the County of Mid Lothian, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN KILNS FOR BURNING LINE," to be as
follows:-
In burning limestone for lime in what is known as the continuous or
draw kiln, the limestone and coal or other fuel are charged in alternate
layers and fired at the bottom, and allowed to burn upwards through the
different layers, the limestone as soon as converted into lime being with-
drawn at the eye or bottom of the kiln, and fresh layers of limestone and
coal or other fuel are put on the top or mouth. The consequence of this

page_text: mode of working is that a large quantity of carbonaceous or heating
matter is carried away in the form of dense smoke, and is lost as each
successive layer of coal is submitted to a distilling process before being
fired.
This Invention has for its object an arrangement of kiln or kilns by
which this carbonaceous matter is to a large extent consumed, and the
heat resulting therefrom made to act upon the limestone in converting
it into lime.
This arrangement consists in constructing the kiln of an oblong form,
say, 10 feet wide, and 40 feet long, having divisions, say, 10 feet each,
carried up to within a few feet of the top of the kiln. Each division is
provided with a proper opening or door for withdrawing the lime at the
bottom. The whole kiln is covered with an arch of brickwork or any
other suitable material, having doors or openings for charging the lime-
stone and fuel. A flue is carried from both ends and middle into a
chimney placed in a convenient position for carrying off the products of
combustion and carbonic acid given off by the limestone. The flue from
each division is also provided with a damper for regulating the draught.
In working the kiln each division is filled with alternate layers of
limestone and fuel in a similar way to that employed in what is known
as the continuous or draw kilns. The two end divisions are then kindled
at the bottom and allowed to burn upwards. As soon as volatile matter
is given off so abundantly that it will burn on the surface, it should be
kindled by throwing in a quantity of red-hot coal, or any other flaming
substance, or it may be allowed to kindle of itself by burning through.
As soon as this takes place, the two middle divisions are fired at the
bottom, the volatile vapours from which, in passing over the end
divisions, are fired and consumed, and consequently the whole of the
arched cover gets highly heated, and reverberates the heat back on to the
fresh stones thrown in, and also kindles the fuel as soon as charged into
the kiln, which now requires a much smaller quantity of fuel, in con-
sequence of the extra heat reverberated from the cover.
The process is
now continued by throwing in stone and coal, or other fuel, alter-
nately; but should the outside division not be so far burned through as
the mid division, the current should be reversed by opening the damper
in the flue leading from the mid division, and closing the one at the end.
A modification of the above may be adapted to the ordinary continuous
or draw kilu as at present extensively used in burning lime, by covering

page_text: the mouth or top of the kiln with a dome of brickwork, or any other
suitable material, and connected by means of flues to a chimney
placed in a suitable position, or a cone may be adopted, placed in
proximity to the dome. In each case a damper is provided for regulating
the draught, the dome being supplied with openings or doors for
admitting the limestone and fuel into the kiln. In this case the dome
becoming highly heated, reverberates the beat back on the limestone,
and also induces the combustion of the volatile carbonaceous matter,
and the heat resulting therefrom acting upon the limestone causes a
large saving of fuel.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Young and William Walker Stephens
in the Great Seal Patent Office on the 24th March 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
YOUNG, Manager of the Lime Works, Straiton, in the County of Mid
Lothian, and WILLIAM WALKER STEPHENS, of Leith, in the said County
of Mid Lothian, Executor of Peter Brash, late of Leith, Soap, Candle,
and Oil Manufacturer, deceased, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of September, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto the said Robert Young and William Walker
Stephens, Her special liceuse that we, the said Robert Young and
William Walker Stephens, our executors, administrators, and assigns,
or such others as we, the said Robert Young and William Walker
Stephens, our executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channc) Islands, and Isle of Man
an Invention for "IMPROVEMENTS IN KILNS FOR BURNING LINE," upon
the condition (amongst others) that we, the said Robert Young and
William Walker Stephens, our executors or administrators, by an
instrument in writing under our or their hands and seals, or under
the hand and scal of one of us them should particularly describe

page_text: and ascertain the nature of the said Invention, and in what manner the
same was to be performed; and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Young, on behalf of myself
and the said William Walker Stephens, do hereby declare the nature
of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
In burning limestone for lime in what is known as the continuous or
draw kiln, the limestone and coal or other fuel are charged in alternato
layers and fired at the bottom and allowed to burn upwards through the
different layers, the limestone as soon as converted into lime being with-
drawn at the eye or bottom of the kiln, and fresh layers of limestone
and coal or other fuel are put on the top or mouth. The consequence of
this mode of working is that a large quantity of carbonaceous or heating
matter is carried away in the form of dense smoke, and is lost as each
successive layer of coal is submitted to a distilling process before being
fired.
This Invention has for its object an arrangement of kiln or kilns by!
which this carbonaceous matter is to a large extent consumed and the
heat resulting therefrom made to act upon the limestone in converting
it into lime.
This arrangement consists in constructing the kiln of an oblong form,
say 10 feet wide and 40 feet long, having divisions say 10 feet each,
carried up to within a few feet of top of kiln; each division is provided
with a proper opening or door for withdrawing the lime at the bottom;
the whole kiln is covered with an arch of brickwork or any other suitable
material, having doors or openings for charging the limestone and fuel;
a flue is carried from both ends and middle into a chimney placed in a
convenient position for carrying off the products of combustion and
carbonic acid given off by the limestone. The flue from each division
is also provided with a damper for regulating the draught.
In working the kiln each division is filled with alternate layers of
limestone and fuel in a similar way to that employed in what is known
as the continuous or draw kilns. The two end divisions are then kindled
at the bottom and allowed to burn upwards. As soon as volatile matter

page_text: is given off so abundantly that it will burn on the surface, it should be
kindled by throwing in a quantity of red hot coal or any other flaming
substance, or it may be allowed to kindle of itself by burning through.
As soon
as this takes place the two middle divisions are fired at
bottom, the volatile vapours from which in passing over the end divisions
are fired and consumed, and consequently the whole of the arched cover
gets highly heated and reverberates the heat back on the fresh stones
thrown in, and also kindles the fuel as soon as charged into the kiln,
and which now requires a much smaller quantity of fuel in consequence
of the extra heat reverberated from the cover. The process is now con-
tinued by throwing in stone and coal or any other fuel alternately, but
should the outside division not be so far burned through as the mid
division the current should be reversed by opening the damper in fluo
leading from mid division and closing the one at the end.
A modification of the above may be adapted to the ordinary continuous
or draw kiln as at present extensively used in burning lime by covering
the mouth or top of kiln with a dome of brickwork or any other suitablo
material, and connected by means of flucs to a chimney placed in a
suitable position, or a conc may be adopted placed in proximity to the
dome. In cach case a damper is provided for regulating the draught,
the dome being supplied with openings or doors for admitting the lime>
stone and fuel into the kiln. In this case the dome becoming highly
heated reverbrates the heat back on the limestone, and also induces the
combustion of the volatilo carbonaceous matter, and the heat resulting
therefrom acting upon the limestone causes a large saving of fuel.
In order that our Invention may be more fully understood and carried
into effect we have in the Drawing hereunto annexed shewn a kiln
constructed according to our Invention.
Figure 1 is a sido elevation partly in section of the kiln; Figure 2 is
a plan of the same also partly in section. The same letters denote the
same parts in both Drawings.
The kiln is divided into vertical compartments, by preference into four
compartments, as shewn. The four compartments A, A, A, A, are first
charged by the openings B, B, B, B, with alternate layers of limestone
and coal or other fuel, a quantity of brushwood or other easily in-
flammable material being placed in the bottom of each compartment;
the covers are then placed on the openings B, B, B, B, at top, and fire

page_text: applied to the two central divisions, and allowed to burn upwards till the
combustible gases fire at the top under the arched cover C, C, C, C, the
products of combustion being caused to pass through and over the layers
of limestone and coal in the two end divisions by opening the dampers
D, D, D, D, at opposite sides in end divisions; the end divisions are now
kindled at the bottom; as soon as the volatile carbonaceous matter from
the end divisions is given off in abundance the current is reversed under
the arched cover C, C, C, by closing the dampers D, D, D, D, and
opening the dampers E, E, E, E; from the mid divisions, the volatile
vapours are thereby caused to pass over the highly heated limestone in
the mid divisions, whereby they are consumed; lime is now drawn from
the mid divisions by the openings F, F, at bottom, and fresh limestone
and coal charged by the openings B, B, at top; as the two outside
divisions have now become highly heated, the current is reversed by
closing the dampers E, E, and opening the dampers D, D. The volatile
carbonaceous vapours from the fresh fuel placed in the mid division
being consumed in passing through and over the limestone in end
divisions. Lime is next drawn from the end divisions by the open-
ings F, F, and fresh layers of limestone and fuel charged by the
openings B, B, at top, and the current again reversed as before; this
process is just repeated continuously. The gases, carbonic acid, &c., are
carried off by the fluc G, G, into the chimney H. To facilitate the
charging of the kilns the rails K, K, are placed on top of arched cover
C, C, C, so that the loads of limestone, &c., are conveyed to the
openings B, B, in arched cover.
From the above description it will be readily seen that by alternately
reversing the current of volatile carbonaceous gases and causing them
to pass through and over the highly heated limestone that they are
consumed, and the resulting heat made to assist in burning the limestone
into lime.
A modification of the above as applied to the ordinary continuous
draw kiln is shewn in Figure 3 and Figure 4; Figure 3 is a longitudinal
section of ordinary draw kiln provided with flues and covered with a
dome-shaped cover; Figure 4 is a plan of the same kiln, partly in
section. A is the body of the kiln; B, the cover or dome; C, C, C, are
openings for charging the limestone and fuel; D, D, are openings into
circular flues E, E, leading to a steam boiler F and the main flue to
chimney; G is a damper by which the heated gases may be caused

page_text: to pass by the flue H leading to chimney, without coming in contact
with the boiler; L is a damper by which the heated gases are passed
through and around boiler; K, K, K, are the openings for withdrawing
the burnt lime.
The kiln is charged and drawn in the same way as the ordinary draw
kiln, but as the heat resulting from the combustion of the volatile
carbonaceous gases cannot be fully taken advantage of in burning the
limestone into lime it may be used for a variety of purposes, such as
drying bricks, &c., or, as shewn in Drawing, to raise steam by causing
the heated products of combustion to circulate round steam boiler before
entering chimney.
In working with the kiln of our Invention, and its application to the
ordinary draw kiln, care should be taken that the current of air passed
through kiln is just sufficient for the complete combustion of the fuel
employed, for if the current of air is too great it tends to cause an over
rapid combustion of the fuel, and carries away the heated products of
combustion before they have had time to act upon the limestone.
Having now described the nature of our Invention, and the manner
in which the same may be carried into effect, we wish it to be understood
that what we claim is,―
1st. The construction of kilns for burning lime, substantially in the
manner herein described and shewn at Figures 1 and 2.
2nd. The construction of kilns for burning lime, substantially in the
manner herein described and shewn at Figures 3 and 4.
In witness whereof, I, the said Robert Young, have hereunto set
my hand and seal, this 21st day of March, in the year of our Lord
One thousand eight hundred and seventy-three.
DADEDT VANNA