IMPROVEMENTS IN LIME KILNS
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the
Office of the Commissioners of Patents, with his Petition, on the
12th June 1871.-A communication from abroad by Alexis Jean
Joseph Robin, junior, of Bel Air de St. Germain le Princay
(Vendée), France, Manufacturer.
I, WILLIAM EDWARD GEDGE, of No. 11, Wellington Street, Strand,
in the County of Middlesex, Patent Agent, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN LIME KILNS," a communi-
cation to me from abroad by Alexis Jean Joseph Robin, junior, of Bel
Air de St. Germain lc_Princay (Vendée), France, Manufacturer, to be as
follows:-
This Invention relates to a system of coupled kilns with inverted
flame and continuous fire by which it is proposed to realise the four
points essential to a cheap manufacture of lime, namely,―
1º. Relatively cheap construction of the works with solidity and
facility of repair.
2º. Economy of manual labour in the manufacture and salubrity for
the labourers.

page_text: .
3°. Economy of fuel and facility of burning fuel of any quality.
4°. Facility of stopping or of simply slackening the working of the
establishment during intervals of rest without putting out the fires.
These kilns with inverted flame have very nearly the shape of ordinary
kilps, with the exception of an inner swelling or protuberance descending
perpendicularly to the sides of the mouth for about two-thirds of the
height of the kiln. The object of these swellings is to bring the coal
shoots further within the kiln, and to loosen the calcareous material or
limestone upon which the coal or other fuel falls; in fact, the limestone
being shot in the middle of the kiln it is only the very large blocks
which in tumbling down touch the sides of the kiln below the swellings.
This arrangement permits the fuel to spread itself readily, and to fall
between the stones to a sufficient depth to thoroughly calcine the entire
charge. At about two-thirds the height of the kiln there come beneath
the swellings six coal shoots at equal distances apart; two other shoots
are placed in the luting of bricks and clay made over the mouth after
the charging of each kiln, and permit the introduction of coal also on.
to the top of the charge of rough limestone on the part the least piled
up. These eight shoots or fuel conduits are stopped exteriorly by small
cast-iron doors closing by falling to. The height of the kilns may reach
between 13 and 17 feet (4 and 5 meters) from above the draft holes to
beneath the mouth; their greatest breadth or belly should be from about
8 feet 4 inches to 10 feet (2 to 3 meters); between the swellings they
should have a breadth of from about 4 feet 4 inches to 5 feet (1m.
30 cents. to 1 m. 50 cents.); and finally in the vertical parts at the axis
of the upper communication flues their breadth will vary between 6 feet
2 inches and 7 feet 4 inches (1m. 85 cents. and 2 m. 20 cents.)
Two communication flues closing with registers or dampers of sheet
iron or of fire-bricks are established between all the kilns of a same
group at the bottom and at the top of the kilns. A flue leading to
the chimney is also provided within the upper communication flues.
To withdraw the burnt lime two draft holes or channels of from 20 to
24 inches (50 to 60 centimeters) from side to side, closing hermetically
by sheet or cast-iron doors, are placed on each side the axis of the kiln
and beneath the lower communication flues; they permit the lime to
fall on to cast-iron gratings, which give passage to the small quantity
of cinders contained in the lime, the lime falling in front of the grating

page_text: and the cinders into small measuring waggons by which they are at
once conveyed to the vehicles intended to carry them away.
The chimney should, for the sake of economy, be placed in the middle
of the brickwork, its height varying between 40 and 70 feet (12 and 20
meters) according to the number of kilns grouped around it and the
altitude of the locality of the works; its inner section should be from
27 to 32 inches (66 to 80 centimeters) for groups of from six to eight
kilns, and of from 3 feet 4 inches to 4 fect (1 meter to 1 m. 20 cents.)
for groups of from twelve to sixteen kilns. .
A steam engine of one-horse power per kiln will amply suffice for
lifting the limestone and the coal to the mouth; it may easily be placed.
upon the brickwork for groups of from 10 to 12 kilns, and above and at
the foot of the kilns for groups of a lesser number.
.
DESCRIPTION OF THE ACCOMPANYING DRAWINGS.
Fig. 1 is a sectional elevation of a kiln embodying this Invention, and
Fig. 2 is a sectional plan and elevation of same.
A, B, C, D, E, F, Figure 2, indicate sections at A, B, C, D, E¹, F¹,
Fig. 1; G (Fig. 2), horizontal plan; H, Fig. 1, vertical section at H',
Fig. 2; I, Fig. 1, vertical section at I, Fig. 2; J (Fig. 1), elevation ;
|K (Fig. 1), chimney. Similar letters of reference denote similar parts
in each of the Figures respectively.
"
a, mouth of kiln and luting of bricks; b, coal shoots or fuel conduits;
c, upper communication flues and dampers; d, lower communication
flues and dampers; f, draft holes or channels; g, cast-iron gratings;
h, lower railway and turntables; i, upper railway and turntables; w,
measuring waggons. The steam engine and its adjuncts and the lift
and stairs are not figured on the Drawing.
Kindling and Working of the Kilns.-The kindling is very easy. One
or two kilns are charged by the usual method for kindling ordinary
kilns, that is to say, by alternate layers of limestone, coal, and wood
(the fuel above the layer for No. 1 kiln and beneath it for No. 2). The
mouth of No. 1 kiln is not closed; the top dampers, the back bottom
one, and that of the flue communicating with the chimney, are closed
all the other kilns, up to that which is in process of charging, have their
dampers regulated so as to cause the current of flame to travel zig-zǝg,
that is to say, so that the flame communicating by the bottom with kila

page_text: No. 2 will escape by the top to penetrate into No. 3 kiln, from which it
Communication
will issue by the bottom to arrive at No. 4, and so on.
with the chimney will only be open through the last-charged kiln,
which it will be understood does not communicate with that which is
in process of being charged. The current of the flame being thus
regulated fire is put to the month of No. 1 kiln, and the kindling takes
place immediately (the kindling might equally well be effected at the
bottom of the kiln).
The working of the apparatus will be readily understood:-No. 1 kiln
having been heated during 12 hours of the day the calcination of its
charge is complete (it being understood that the kiln is in regular work),
and it has already prepared for calcination the kiln No. 2, which will
be heated in the 12 following night hours; thus the entire time for
calcination in a couple is 24 hours. During the next 24 hours the
charge in Nos. 3 and 4 will be calcined, and kilns Nos. 1 and 2 will be
cooled by the passage of the cold air which will pass into Nos. 3 and 4.
On the third day the emptying and refilling of kilns Nos. 1 and 2 will
be effected simultaneously, while Nos. 5 and 6 are being kindled, and
so on. With a group of from 10 to 12 kilns at the least it will be found
preferable to kindle.two alternate couples of kilns, the Nos. 1 and 3
during the first 12 hours, and the Nos. 2 and 4 during the succeeding
12 hours, thus obtaining in 24 hours (one day and one night) the com-
plete calcination of the contents of these four kilns with a greater
economy of fuel than if one couple only were kindled. With from 14 to
16 kilns 3 alternate couples of kilns may be kindled simultaneously, and
so on.
It will be evident from the accompanying Drawing and the above
description that the construction of the kilns may be modified while
retaining this Invention, which consists essentially in the coupling and
grouping of the kilns in more or less number, and in the inversion of
the flame. Thus, instead of giving to the kiln a height of from 13
to 17 feet (4 or 5 meters), they may equally well be raised to double or
treble that height; that is to say, two or three groups may be super-
posed the one above the other, and the communication flues be placed
only at the top and the bottom of the brickwork. They may also be
constructed of greater breadth, but at the expense of their interior
strength; and it is equally easy to construct them with their axis

page_text: inclined, and the coal shoots on one side only. When a very large
number of kilns is needed they may be grouped in two concentric
circles, and be coupled in zig-zag, one of the outer circle with one of
the inner circle, and so on.
It should also be observed that it is very easy to make use of the
brickwork or masonry of certain existing kilns for the creation of
establishments of this kind, and at a relatively small cost.