IMPROVEMENTS IN THE CONSTRUCTION OF KILNS FOR THE MANU- FACTURE OF LIME AND CEMENT OR FOR THE CALCINING OF ORES OR OTHER MANAT OF A Abent in
Year: 1869

page_text: LETTERS PATENT to Robert Elsdon, of Brockham, in the Parish
of Betchworth, in the County of Surrey, Engineer, for the Inven
tion for "IMPROVEMENTS IN THE CONSTRUCTION OF KILNS FOR THE MANU-
FACTURE OF LIME AND CEMENT OR FOR THE CALCINING OF ORES OR OTHER
MANAT OF A
Abent in "
Sealed the 19th October 1869, and dated the 30th April 1869.
PROVISIONAL SPECIFICATION left by the said Robert Elsdon at the
Office of the Commissioners of Patents, with his Petition, on the
30th April 1869.
I, ROBERT ELSDON, of Brockham, in the Parish of Betchworth, in
the County of Surrey, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF KILNS FOR THE
MANUFACTURE OF LIME AND CEMENT OR FOR THE CALCINING OF ORES OR OTHER
MATERIAL OF A LIKE NATURE REQUIRING TO BE CALCINED," to be as follows:-
A furnace built at one end or at foot of kiln is divided into chambers
or compartments, the first of which is designed for the combustion of
coal or other fuel, beyond which is a second chamber or compartment

page_text: in which coke or other suitable fuel is burnt. The gases from the first
pass over and are brought into immediate contact with the heated fuel
in the second chamber or compartment, and are there mixed with a
larger quantity of atmospheric air than is necessary for perfect com-
bustion of the fuel, the total products of combustion and distillation from
the second chamber or compartment, and then passes through a brick
chamber, where a still further supply of air is introduced sufficient to
reduce the temparature of the gases to the degree of heat required.
From this chamber the results of combustion plus the atmospheric
air pass into the body of the kiln through the stop arch of fire-brick
perforated for that purpose, the kiln may be either vertical or hori
zontal or at an angle between these, preferably I place the kiln at an
angle inclined to the horizon at a somewhat greater angle than the
natural slope of the material to be calcined. The kiln is filled with
the material to be calcined mixed with a small proportion of carbona-
ceous fuel, the combustion of which completes the calcination. The
upper part of the kiln is fitted with a hopper or other arrangement for
the purpose of charging the kiln, and a chimney for carrying off the
waste gases. Apertures are placed at convenient places in the body
of the kiln for the purpose of watching, & if necessary firing and
mechanically assisting the descent of the material calcining.
opening is placed beneath the foot of the kiln for the purpose of drawing
it, by which the lime, cement, or other calcined materials are continuously
delivered.
An
SPECIFICATION. in pursuance of the conditions of the Letters Patent,
filed by the said Robert Elsdon in the Great Seal Patent Office
on the 26th October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
ELSDON, of Brockham, in the Parish of Betchworth, in the County of
Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of April, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,

page_text: give and grant unto me, the said Robert Elsdon, Her special
licence that I, the said Robert Elsdon, my executors, administrators,
and assigns, or such others as I, the said Robert Elsdon, my
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 Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF KILNS FOR THE MANUFACTURE OF LIME AND
CEMENT OR FOR THE CAICINING OF ORES OR OTHER MATERIAL OF A LIKE NATURE
REQUIRING TO BE CALCINED," upon the condition (amongst others) that
I, the said Robert Elsdon, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
should particularly describe 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 Elsdon, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement :-
A furnace built at one end or foot of kiln for combustion of coal or
other fuel; beyond this is a second furnace in which coke or other
suitable fuel is burnt; the gases from the first pass over and are
brought into immediate contact with the heated fuel in the second
furnace, and are there mixed with a larger quantity of atmospheric air
than is necessary for perfect combustion of the fuel. The total product
of combustion and distillation from the coke furnace passes through a
brick chamber, where a still further supply of air is introduced sufficient
to reduce the temperature to the degree required. From this chamber
the results of combustion plus the atmospheric air passes in the body of
the kiln through the stop arch of fire-brick perforated for that purpose;
the kiln may be either vertical or horizontal or at an angle between
these, preferably I place the kiln at an angle inclined to the horizon
at a somewhat greater angle than the natural slope of the material to be
calcined. The kiln is filled with the material to be calcined mixed with

page_text: a small proportion of carbonaceous fuel, the combustion of which
eompletes the calcination. The upper part of the kiln is fitted with a
hopper or other arrangements for the purpose of charging the kiln, and
a chimney for carrying off the waste gases. Apertures are placed at
convenient places in the body of the kiln for the purpose of watching
and if necessary firing and mechanically assisting the descent of the
material calcining. An opening is placed beneath the foot of the kiln
for the purpose of drawing the kiln from which the lime or other
calcined materials are delivered continuously.
I now proceed to describe the Drawings.
Fig. 1 shews a kiln constructed on my plan, or rather a pair of kilns
combined, ane-half of which or one kiln is in section. The other half
shews a kiln in elevation; Fig. 2 is part plan and part sectional plan of
one of the pair of kilns shewn above; one-half is, a full plan, the other
is a sectional plan on the line A, B, Fig. 1. The same letters of
reference apply to the same parts on each Figure.
a is the furnace at the end of the kiln in which coal or other fuel is
burnt; b, furnace next beyond for combustion of coke or other smokeless
fuel; c, air chamber in which a supply of atmospheric air is admitted
and regulated by damper c. to reduce and regulate temperature of gases
af combustion and distillation that pass from the furnaces a and b; d is
a stop arch of fire-brick slabs, through which the gases pass into the
body of kiln e in which the chalk or other material to be calcined is
placed. The body of the kiln is by preference constructed in form as
shewn in the Drawings so as to facilitate the free passage of the chalk
or other material from the trap or hopper f through which the kiln is
fed to the lower aperture g, from where it issues as lime or other calcined
material. For this purpose I give an inclination to the side of the kiln
greater than the limiting angle of resistance or than the natural angle
at which the material being calcined would stand, and by doing this I
expect that the material will naturally descend by reason of gravity and
deliver itself, and when the lower part is drawn from the lower door or
aperture g the superincumbent mass will slide down to fill the place left
vacant by the lime or other calcined material removed, At the same
level as the feeding aperture f is a smaller hopper or door h, through
which I propose to put from time to time a small proportion of coke,
breeze, or other smokeless fuel in proper proportions and in such a way

page_text: that it shall take up its proper position in the body of the kiln, and
which by combustion combines with the gases passing up through the
kiln and assists the calcining of the material in the kiln. The apertures
i, i, i, on the kiln are made for the purpose of getting access to the body
of the kiln to assist descent should there be any sticking or lodging of
the material calcining, or for introduction of fuel to assist calcination.
The kilns here shewn and above described are constructed in pairs back
to back with archway N between them, in which is laid a tramway k,
upon which if required waggons or trucks may pass beneath the kilns
and take up and load the lime or other calcined material from off the
bench on which the kiln is discharged from the door g, and which is
marked in the Drawing. The fuel and material is supplied to the
kiln by the tram m leading from the ground to level of hopper, on which
level a platform o for labourers would be constructed.
The action of the kiln is as follows:-The fire is lighted in the furnace
a, and the gases arising from this pass over the incandescent fuel in the
furnace b and there mix with the atmospheric air admitted into chamber
c, and thus mixed pass through the stop arch d into the kiln, passing
through the material to be calcined till they escape from the chimney n
at a temperature I expect not exceeding 600° or thereabouts. A damper
is fitted to the top of the chimney.
Another arrangement of my Invention is shewn in Figs. 3 and 4,
which is that of a single kiln built against the side of a hill or a support
erected for the purpose, and in which the letters of reference are the
same as in the preceeding description.
Having thus described the nature of my Invention, and manner in
which I prefer executing same, I desire it to be understood that. I
claim,
1. I claim the arrangement as above described of a double furnace
combined with an air chamber as applied to the construction of kilns
for the manufacture of lime and cement, or for the calcining of ores or
other material requiring to be calcined.
And, 2. I claim the arrangement above described whereby the material
is calcined partly by a furnace or furnaces outside the kiln and partly by
fuel mixed with the material requiring to be calcined, or entirely by the

page_text: one or the other as the state of the kiln or the nature of material under
calcination demands.
In witness whereof, I, the said Robert Elsdon, have hereunto
set my hand and scal, this Twenty-sixth day of October, in
the year of our Lord One thousand eight hundred and sixty- i
nine.
ROBERT ELSDON. (L.S.)