IMPROVEMENTS IN CALCINING MATERIALS FOR THE MANUFACTURE OF PORTLAND CEMENT AND SUBSTANCES, AND IN THE KILNS OR OVENS EMPLOYED THEREIN." OTHER
Year: 1879

page_text: LETTERS PATENT to Edward James Atkinson, of Fenchurch Street, in the City
of London, Merchant, for the Invention of. "IMPROVEMENTS IN CALCINING
MATERIALS FOR THE MANUFACTURE OF PORTLAND CEMENT AND
SUBSTANCES, AND IN THE KILNS OR OVENS EMPLOYED THEREIN."
OTHER
PROVISIONAL SPECIFICATION left by the said Edward James Atkinson at
the Office of the Commissioners of Patents on the 21st February 1879.
EDWARD JAMES ATKINSON, of Fenchurch Street, in the City of London,
Merchant. "IMPROVEMENTS IN CALCINING MATERIALS FOR THE MANUFACTURE
OF PORTLAND CEMENT AND OTHER SUBSTANCES, AND IN THE KILNS OR OVENS
EMPLOYED THEREIN.' "
My Invention relates to the method of calcining, and the kilns or ovens therefor,
described in the Provisional Specification filed by me, with a former application for
Letters Patent, the 5 December 1878, No. 4982, and it consists of improvements
having for their object rendering the said kilns or ovens especially adapted for use
in the manufacture of Portland cement, whilst the said kilns or ovens thus improved
are also applicable to the calcining of gypsum, lime, and other materials.
In carrying out my present Invention I employ as the calcining agent a current
of heated air, as described in my said former Provisional Specification, and I
introduce the same into a chamber whence it is conducted in the manner hereinafter
described into a calcining chamber or chambers arranged at one or both sides of the
first mentioned or air supply chamber. The calcining chamber (or each of the
calcining chambers when more than one are employed) is divided by transverse
chambers extending across the calcining chamber and communicating with the air
supply chamber. These transverse chambers are provided in their walls or sides
with small perforations through which the heated air conducted from the air supply
chamber into the transverse chambers escapes into or among the materials (mud or
clay and chalk for example) to be operated upon contained in the calcining chamber
or chambers. The perforations are shielded by inclined projections arranged above
them which prevent all liability of their becoming obstructed by the material under
treatment, and at the same time serve as guides to change the direction of the

page_text: material in its descent, for which purpose, and also with the view of better
distributing the heat, the perforations with their inclined shields may be arranged
quincuncially, or so as to "break joint."
The transverse chambers, and also the calcining chamber or chambers, are
composed of or lined with fire brick or other suitable refractory material, which
whilst enabling the apparatus to sustain the elevated temperature to which it has
to be subjected will also contribute to the maintenance of such elevated temperature
by the absorption and retention of the heat.
The mass of material under operation is thus maintained at an elevated
temperature between the walls of the transverse chambers which divide the
calciuing chamber or chambers, whilst the portion of the material above undergoes
a preliminary heating by the ascending current of heated air; and as the lower or
calcined portion is drawn the upper portion taking its place is in its turn raised to
an elevated temperature between the transverse chambers, whilst a fresh portion
introduced above takes the place of the portion which has descended, the kiln being
maintained constantly full by the introduction of fresh material above as the calcined
material is drawn below without any intermission or interruption during the
working of the kiln.
The heat after passing through the kiln, or the hot air direct from the stoves,
may be utilized for drying by means of floors or otherwise the "slurry," or mixture,
or other material before it is subjected to the operation of the kiln itself.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward James Atkinson in the Great Seal Patent Office on the
20th August 1879.
EDWARD JAMES ATKINSON, of Fenchurch Street, in the City of London,
Merchant. "IMPROVEMENTS IN CALCINING MATERIALS FOR THE MANUFACTURE
OF PORTLAND CEMENT AND OTHER SUBSTANCES, AND IN THE KILNS OR OVENS
EMPLOYED THEREIN."
My said Invention relates to the method of calcining, and the kilns or ovens
therefor, in respect of which former Letters Patent were granted to me dated the
5th December, One thousand eight hundred and seventy-eight, No. 4982, and it
consists of improvements having for their object rendering the said kilns or ovens
especially adapted for use in the manufacture of Portland cement, whilst the said
kilns or ovens thus improved are also applicable to the calcining of gypsum, lime,
and other materials.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of my Drawings represents a transverse vertical section taken along the
line 1-2 (Figure 3) of a kiln or oven constructed for the purpose of carrying out
my said Invention; Figure 2 is a longitudinal section of the same taken along the
line 3-4 (Figure 1), and Figure 3 is a horizontal section taken along the line 5-6
(Figure 1).
In carrying out my present Invention I employ as the calcining agent a current
of heated air, as described in my said former Specification, and I introduce the same
through a fire brick tube a into a chamber A whence it is conducted in the manner
hereinafter described into calcining chambers B, B, arranged one at each side of the
air supply chamber A. The calcining chambers B, B, are divided by transverse
chambers C, C, extending across the same and communicating with the air supply
chamber A. These transverse chambers are provided in their walls or sides with
small apertures b, b, through which the heated air conducted from the air supply
chamber A into the transverse chambers C, C, escapes into and among the materials
(mud, or clay and chalk for example) to be operated upon contained in the calcining
chamber or chambers B, B. The apertures b, b, are shielded by inclined projections c, c,
arranged above them which prevent all liability of their becoming obstructed by
the material under treatment, and at the same time serve as guides to change the
direction of the material in its descent, for which purpose and also with the view
of better distributing the heat the apertures with their inclined shields may be
arranged quincuncially or so as to "break joint," as shown.
The transverse chambers C, C, and also the calcining chamber or chambers B, B,
are composed of or lined with fire brick or other suitable refractory material, which
whilst enabling the apparatus to sustain the elevated temperature to which it has
to be subjected will also contribute to the maintenance of such elevated temperature
by the absorption and retention of the heat.
The mass of material under operation is thus maintained at an elevated
temperature between the walls of the transverse chambers C, C, which divide the
calcining chambers B, B, whilst the portion of the material above undergoes &
preliminary heating by the ascending current of heated air; and as the lower or
calcined portion is drawn the upper portion taking its place is in its turn raised to
an elevated temperature between the transverse chambers C, C, whilst a fresh
portion introduced above (by the feed openings d, d,) takes the place of the portion
which has descended, the kiln being maintained constantly full by the introduction
of fresh material above as the calcined material is drawn below without any
intermission or interruption during the working of the kiln.

page_text: The calcined material may be discharged from the kiln in any convenient manner
through shoots or inclined passages D, Ď, provided with external sliding doors (the
latter not shown in the Drawing).
In lieu of making the kiln double, as herein before described, single acting kilns
may be constructed, that is to say, one calcining chamber may be employed on one
side only of the chamber A in place of on both sides, as in the example described
and illustrated; or either the single or double calcining chambers and the air
supply chamber may be divided by partitions so as to form compartments capable
of being worked-separately or in any combination as required.
The heat after passing through the kiln, or the hot air direct from the stoves may
be utilized for drying by means of floors or otherwise the "slurry," or mixture, or
other material before it is subjected to the operation of the kiln itself.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,―
The combination in a kiln or oven of a calcining chamber or chambers and
transverse chambers with apertures, the said parts being constructed, arranged, and
combined as herein set forth for effecting the calcination, by the employment of a
current of heated air, of materials for the manufacture of Portland cement and
other substances, all substantially as hereinbefore described.
·
In witness whereof, I, the said Edward James Atkinson, have to this my
Specification set my hand and seal, the Ninth day of August, One thousand
eight hundred and seventy nine.