IMPROVEMENTS IN BURNING OR CALCINING LIMESTONE AND CEMENT AND IN OVENS OR APPARATUS EMPLOYED FOR THAT PURPOSE
Year: 1867

page_text: LETTERS PATENT to Henry Wadkin and Charles Shepherd, both of
Chester, in the County of Chester, for the Invention of "IMPROVEMENTS
IN BURNING OR CALCINING LIMESTONE AND CEMENT AND IN OVENS OR
APPARATUS EMPLOYED FOR THAT PURPOSE."
Sealed the 16th August 1867, and dated the 21st February 1867.
PROVISIONAL SPECIFICATION left by the said Henry Wadkin and
Charles Shepherd at the Office of the Commissioners of Patents, with
their Petition, on the 21st February 1867.
We, HENRY WADKIN' and CHARLES SHEPHERD, both of Chester, in the
County of Chester, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN BURNING OR CALCINING LIMESTONE AND CEMENT AND IN OVENS
OR APPARATUS EMPLOYED FOR THAT PURPOSE," to be as follows:-
Our Invention consists in burning or calcining limestone and cement in
closed chambers or receptacles so arranged that while the flames and hot
gases from the fuel pass through or in contact with the limestone or cement
the fuel itself is kept entirely separate from the same, and thus the dete--
rioration of a great proportion of the product, such as takes place under the
present system of burning, is prevented. For this purpose we construct a.
closed chamber, by preference of some length in proportion to its width and..
height, provided at top with one or more apertures having covers, through.
which the chamber is charged with the material to be burnt, and having one or..
more doors at the front end level with the floor of the chamber, through which,
the material is drawn when burnt. One, two, or more furnaces, arranged
either beneath the said chamber or ou each side thereof, have flues which

page_text: communicate with the chamber through openings formed in each side close
to the front end of the same, through which openings the whole of the flames
and hot products of combustion from the furnaces pass into the chamber. At
the back end the chamber communicates by means of a flue with a chimney
shaft, through which the products of combustion escape after having traversed
the entire length of the chamber. A perforated partition is built a short dis-
tance from the back end of the chamber, which while permitting the free
passage of the draught prevents any of the material with which the chamber
is charged from entering the said flue. The space between this partition and
the end of the chamber is rendered accessible through one or more openings
provided with covers or doors for the purpose of removing any particles of
limestone or cement that may have fallen through the partition. The furnaces
are by preference arranged one on each side of the chamber, running parallel
with the same, and the flues are brought forward from the back ends of the
furnaces to the before-mentioned openings in the sides near the front end of
the chamber. A number of these apparatus may be arranged side by side so
as to admit of the one being charged while the other or others is or are being
drawn or fired, in which case the flues at the back ends of the chambers may
all communicate with one main flue, through which the products of combus-
tion are conducted to one large chimney shaft. All the flues are provided
with suitable dampers or valves for cutting off or regulating the draught.
The chambers are in the first instance charged through the top openings,
which are then closed with the covers, and the contents of the chamber are
then fired. When the process of burning or calcining has been completed,
the front door or doors, as also the top apertures of the chamber, are opened
in order to cool the charge as rapidly as possible, after which the charge is
drawn through the front door or doors. The chambers are by preference
provided with any suitable known arrangement of pyrometer for indicating
the heat in the chamber for the purpose of regulation, and in order to
determine when the charge has been sufficiently calcined. The floor of the
chamber may either be made horizontal, or at any incline to facilitate the
drawing, in which case the charge may be prevented from choking up the
apertures communicating with the furnaces by means of a series of removeable
bars placed across the chamber so as to keep the charge some distance cleat
of the front or lower end of the chamber. The above-described apparatus
may be made either stationary and entirely of brickwork, or it may be made
portable and be provided with an iron casing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed:
by the said Henry Wadkin and Charles Shepherd in the Great Seal
Patent Office on the 20th August 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ПENRY
WADKIN and CHARLES SHEPHERD, both of Chester, in the County of Chester,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of February, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirtieth year of
Her reign, did, for Herself, Her heirs and successors, give. and grant unto
us, the said Henry Wadkin and Charles Shepherd, Her special licence
that we, the said Henry Wadkin and Charles Shepherd, our exccutors,
administrators, and assigns, or such others as we, the said Henry Wadkin
and Charles Shepherd, our executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 "IMPROVEMENTS IN
BURNING OR CALCINING LIMESTONE AND CEMENT AND IN OVENS OR APPARATUS
EMPLOYED FOR THAT PURPOSE," upon the condition (amongst others) that we,
the said Henry Wadkin and Charles Shepherd, our executors or adminis-
trators, by an instrument in writing under our or their hands and seals, or
under the hand and seal of one of us or them, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same was
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 we, the said Henry Wadkin and Charles
Shepherd, do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, reference being had to the
accompanying Sheet of Drawings, and to the figures and letters marked
thereon, that is to say. :-
Our Invention consists in burning or calcining limestone and cement in
closed chambers or receptacles so arranged that while the flames and hot
gases from the fuel pass through or in contact with the limestone or cement
the fuel itself is kept entirely separate from the same, and thus the deterioration
of a great proportion of the product, such as takes place under the present

page_text: system of burning, is prevented. For this purpose we construct a closed
chamber, by preference of some length in proportion to its width and height,
provided at top with one or more apertures having covers, through which the
chamber is charged with the material to be burnt, and having one or more
doors at the front end level with the floor of the chamber, through which the
material is drawn when burnt. One, two, or more of the furnaces, arranged
either beneath the said chamber or on each side thereof, have flues which com-
municate with the chamber through openings formed on each side close to
the front end of the same, through which openings the whole of the flames
and hot products of combustion from the furnaces pass into the chamber.
At the back end the chamber communicates by means of a flue with a
chimney shaft, through which the products of combustion escape after having
traversed the entire length of the chamber. A perforated partition is built
a short distance from the back end of the chamber, which while permitting
the free passage of the draught prevents any of the material with which the
chamber is charged from entering the said flue. The space between this
partition and the end of the chamber is rendered accessible through one or more
openings provided with covers or doors for the purpose of removing any
particles of limestone or cement that may have fallen through the partition.
The furnaces are by preference arranged one on each side of the chamber
running parallel with the same, and the flues are brought forward from the
back ends of the furnaces to the before-mentioned openings in the sides near
the front end of the chamber. A number of theso apparatus may be arranged
side by side so as to admit of the one being charged while the other or others
is or are being drawn or fired, in which case the flues at the back end of the
chambers may all communicate with one main flue through which the products
of combustion are conducted to one large chimney shaft; all the flues are
provided with suitable dampers or valves for cutting-off or regulating the
draught. The chambers are in the first instance charged through the top
openings, which are then closed with the covers, and the contents of the chamber
are then fired. When the process of burning or calcining has been completed
the front door or doors, as also the top apertures of the chambers, are opened
in order to cool the charge as rapidly as possible, after which the charge is
drawn through the front door or doors. The chambers are by preference
provided with any suitable known arrangement of pyrometer for indicating
the heat in the chamber for the purpose of regulation, and in order to determine
when the charge has been sufficiently calcined. The floor of the chamber
may either be made horizontal or at any incline to facilitate the drawing,
in which case the charge may be prevented from choking up the apertures

page_text: communicating with the furnaces by means of a series of removeable bars
placed across the chamber so as to keep the charge some distance clear of the
front or lower end of the chamber.
The above described apparatus may be made either stationary and entirely
of brickwork, or it may be made portable and be provided with an iron
casing..
On the accompanying Sheet of Drawings is shown the construction of ovens
we prefer to employ in carrying our Invention into practice.
Figure 1 shows a part front elevation and part transverse section of a
number of these ovens arranged side by side; Figure 2 shows a part plan and
part sectional plan of the same; Figure 3 shows a longitudinal section through
the chamber containing the charge to be burnt; and Figure 4 shows a longi-
tudinal section through one of the furnaces. Similar letters of reference indicate
similar parts in each of the Figures..
A, A, are long closed chambers of fire-brick provided at the top with openings
B, through which the charge of limestone or cement to be burnt is introduced,
which openings during the process of burning are closed with covers C, C;
at the front end of the chambers are large doors D, D, through which the
material is removed after the process of burning or calcining is completed.
The floors of the chambers are formed so as to slope towards these doors to
facilitate the removal of the charge. Near the back wall of the chamber is
formed a perforated fire-brick partition E, which retains the material with
which the chamber is charged, while it allows the free passage of the draught
through the space F and aperture G into the common flue H running along
the back of and communicating with all the ovens, and serving to conduct the
draught to a chimney shaft not shown on the Drawing. The space F is
rendered accessible through an opening I at top provided with a cover for
clearing out any particles of lime or cement that may from time to time fall
through the partition E. Dampers K are provided for regulating the draught
of each oven, and for cutting-off the communication with the flue H when the
chambers are charging or discharging. The firing of each chamber is effected
by means of two furnaces L, L, one on each side of the chamber A, the flames
and hot gases being conducted from the back end of the furnace through the
flues M to the openings N formed in the front end of the side walls of the
chamber, so that the flames and hot gases entering such chamber through
these openings are caused to traverse the entire length thereof in a very
equally distributed manner on their way to the flue H, thereby effecting the
burning or calcining of the limestone or cement very perfectly, and without

page_text: that deterioration of the product which takes place in kilns or ovens where
the fuel is contained in the same chamber as the material to be burnt.
Having thus described the nature of our Invention, and in what manner the
same is to be performed, what we claim is,-
First, burning or calcining limestone and cement in such manner that while
the flames and hot gases from the fuel employed pass among and act upon the
material the fuel itself is kept separate therefrom; substantially as herein-before
set forth.
Second, constructing ovens or apparatus for burning limestone and cement
separate from the fuel employed for that purpose arranged and operating
substantially as herein-before described with reference to the accompanying
Sheet of Drawings.
In witness whereof, we, the said Henry Wadkin and Charles Shepherd,
have hereunto set our hands and seals, this Sixteenth day of August,
in the year of our Lord One thousand eight hundred and sixty-
seven.