IMPROVEMENTS IN KILNS
Year: 1877

page_text: LETTERS PATENT to James Cramphorn, of Merstham, in the County of Surrey,
for the Invention of "IMPROVEMENTS IN KILNS."
PROVISIONAL SPECIFICATION left by the said James Cramphorn at the
Office of the Commissioners of Patents on the 22nd February 1877.
JAMES CRAMPHORN, of Merstham, in the County of Surrey
KILNS."
This Invention has for its object improvements in kilns.
"IMPROVEMENTS IN
At the present time lime is commonly burnt in kilns of a dome-like form. At
the bottom of the kiln are fire-bars on which the fuel is burnt. The chalk to be
burnt into lime is arched over these fire-bars, and fills the interior of the kiln body
nearly to the top, where there is an outlet for the gaseous products. On one side of
the kiln near the bottom there is an opening, called the throat, formed through the
wall of the kiln (which at this part is several feet in thickness), and fire-doors are
fitted at the outer end of the opening or throat. The fire-bars extend up to the
fire-doors underneath the arch turned in the kiln wall to form the throat. From
this construction it results that the throat of the kiln becomes rapidly impaired by
the heat of the fire extending beneath the wall of the kiln, and constant repairs are
necessary.
To avoid this evil, and also the waste of fuel which likewise results from the
present construction, I place the fire-doors within a few inches of the inner face of
the kiln wall, thus leaving the space beneath the wall which heretofore has formed
the throat on the outer side of the fire-doors, and freely open to the air. I also
enlarge this arched opening as it approaches the outer face of the kiln wall to give
readier access to the fire-doors and to the kiln mouth.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Cramphorn in the Great Seal Patent Office on the 8th August
1877
JAMES CRAMPHORN, of Merstham, in the County of Surrey.
"IMPROVEMENTS IN

page_text: At the present time flare lime is commonly burnt in kilns of a dome-like form.
At the bottom of the kiln are fire-bars on which the fuel is burnt. The chalk to be
burnt into lime is arched over these fire-bars, and fills the interior of the kiln body
nearly to the dome, where there is an outlet for the smoke and gaseous products.
On one side of the kiln near the bottom there are openings, called the throats,
formed through the wall of the kiln (which at this part is several feet in thickness),
and fire-doors are fitted at the outer end of these openings or throats. The fire-bars
extend up to the fire-doors underneath the arches turned in the kiln. wall to form
the throats. From this construction it results that the throats of the kilns become
rapidly injured by the heat of the fire extending beneath the wall of the kiln, and
constant repairs are necessary.
To avoid this evil, and also the waste of fuel which likewise results from the
present construction, I place the fire-doors within a few inches of the inner face of
the kiln wall, thus leaving the space beneath the wall (which heretofore has formed
the throat) on the outer side of the fire-doors, and freely open to the air. I also
enlarge this arched opening as it approaches the outer face of the kiln wall to give
readier access to the fire-doors and to the kiln mouth.
In order that my said Invention may be most fully understood and readily carried
into effect I will proceed to describe the Drawings hereunto annexed.
Figure 1 is an elevation of that portion of the wall of a lime kiln in which the
opening for the fire is formed; Figure 2 is a section taken on the line A, B, in
Figure 3; Figure 3 is a sectional plan; the section is taken immediately above the
level of the fire-bars.
The kiln, of which these Figures represent a portion, is about fourteen feet long
and twelve feet wide in the interior, and two sets of fire-bars are provided; they
are equidistant from the centre line of the kiln. The arrangement is that which I
prefer in carrying my Invention into effect.
a, a, are the massive side walls of the kiln; b is an arch turned in this wall of a
span sufficient to embrace the two fire openings; c is a thinner wall built beneath
the arch b. The openings increase in width as they approach the front to afford
ready access to the fire-doors d, which are placed close to the inner face of the
wall a in place of flush with its outer face, as is now usual. The throats of the kiln
are thus done away with. e, e, are the fire-bars, which as heretofore extend nearly
to the further wall of the kiln, but at the front they stop short, as the Drawings
show, so as to extend but a very short distance beneath the arch b, turned in the
wall a.
In other respects the kiln is constructed and worked in the usual manner.
Having thus described the nature of my said Invention and the manner of per-
forming the same, I would have it understood that I claim, the construction of kilns
with the fire-openings and parts in immediate connection therewith, substantially as
described.
In witness whereof, I, the said James Cramphorn, have hereunto set my
hand and seal, this Eighth day of August, in the year of our Lord One
thousand eight hundred and seventy-seven.
J. CRAMPHORN. (L.S.)