IMPROVEMENTS IN CALCINING GYPSUM, LIME, AND OTHER LIKE MATERIALS, AND IN THE KILNS OR OVENS EMPLOYED THEREIN
Year: 1878

page_text: LETTERS PATENT to Edward James Atkinson, of Fenchurch Street, in the
City of London, Merchant, for the Invention of "IMPROVEMENTS IN CALCINING
GYPSUM, LIME, AND OTHER LIKE MATERIALS, AND IN THE KILNS OR OVENS
EMPLOYED THEREIN.”
Sealed the 13th June 1879, in pursuance of an Order of the Lord Chancellor, and
1
T
1070
Sealed the 13th June 1879, in pursuance of an Order of the Lord Chancellor, and
dated the 5th December 1878.
PROVISIONAL SPECIFICATION left by the said Edward James Atkinson at
the Office of the Commissioners of Patents on the 5th December 1878.
EDWARD JAMES ATKINSON, of Fenchurch Street, in the City of London, Merchant.
"IMPROVEMENTS IN CALCINING GYPSUM, LIME, AND OTHER LIKE MATERIALS, AND IN
THE KILNS OR OVENS EMPLOYED THEREIN.'
"
My Invention relates to improvements in calcining gypsum, lime, and other like.
materials, whereby greater economy in the consumption of fuel is effected and a
more regular and certain calcination is obtained, whilst at the same time the
resulting products is maintained uncontaminated with the products of combustion.
In carrying out my Invention I dispense with the use of an internal fire or
furnace, and employ as the calcining agent a blast of air heated separately or inde-
pendently of the kiln by means of any suitable stove or apparatus.. In utilizing or
applying this calcining agent I construct the kiln with a central chamber at or
towards the base, by preference of an elongated rectangular section, into which
chamber the heated air is forced in any convenient manner. On each side of this
central chamber I provide an elevated side chamber, the two side chambers thus
formed constituting the calcining chambers, into which the gypsum, lime, or other
like material to be operated upon is introduced from the upper part, and into
which the heated air is conducted from the central chamber in the following
manner: From the central chamber at each side thereof extend tubes, which pass
through the partition walls between the central chamber and the calcining cham-
bers into the external walls of the latter, so as whilst forming conduits for the

page_text: heated air to act as stays and afford support to the said walls. The tubes, which
are open at their inner ends to the central chamber and closed at their outer end by
or in the external walls of the calcining chambers, are perforated at their lower side
in such a manner that the heated air which passes from the central chamber along
the tubes escapes through the said perforations, and is thus diffused or distributed
among the material which has been introduced into the calcining chambers. The
material is thus calcined at the lower part of the kiln, without being brought into
contact with the products of combustion, and is drawn or discharged through
shoots or inclined passages below in any convenient manner, and the heated air
ascending at the same time partially dries the material at the upper part pre-
paratorily to its descent to take the place of the lower portion as it is calcined and
drawn, fresh material being then supplied from above, so that the chamber is always
full, the whole of the heat is utilized under the most advantageous conditions, and
the operation proceeds continuously without any intermission or interruption in the
working of the kiln.

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 2nd
July 1879.
EDWARD JAMES ATKINSON, of Fenchurch Street, in the City of London, Merchant.
"IMPROVEMENTS IN CALCINING GYPSUM, LIME, AND OTHER LIKE MATERIALS, AND IN
THE KILNS OR OVENS EMPLOYED THEREIN."
My said Invention relates to improvements in calcining gypsum, lime, and other
like materials, such for example as ores, and consists in the employment of a blast
of heated air as the calcining agent in a kiln or oven of the construction hereinafter
described, whereby greater economy in the consumption of fuel is effected, and a
more regular and certain calcination is obtained, whilst at the same time the
resulting product is maintained uncontaminated with the products of combustion.
In carrying out my said Invention I dispense with the use of an internal fire or
furnace, and heat the air employed as the calcining agent as before mentioned,
separately or independently of the kiln by means of any suitable stove or apparatus.
I also construct the kiln in such a manner that the heated air supplied to it shall
be caused to pass in finely divided streams into and among the material, which is
introduced into the calcining chamber or chambers, and to be thus diffused and
distributed through the mass of such material so as to be utilized in the calcination
and heating of the same under the most advantageous conditions.
And in order that my said Inventon 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 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 1-2 (Figure 1); and Figure 3
is a horizontal section taken along the line 3-4 (Figures 1 and 2).
On
The kiln is constructed at or towards its base with a central chamber A, into
which air heated to the required regulated temperature by any suitable means,
separately or independently of the kiln, is forced in any convenient manner.
each side of this central chamber is an elevated side chamber B, the two side cham-
bers B, B, constituting the calcining chambers, and into these chambers is intro-
duced through openings a, a, at their upper part the gypsum, lime, or other like
material to be operated upon. The calcination of the material thus introduced into
the calcining chambers B, B, is effected by means of the heated air supplied to the
central chamber A by the pipe B', and which heated air is conducted into and
among the material contained into the said chambers B, B, in the following
manner :-
From the central chamber A at each side thereof extend tubes C, C, which pass
through the partition walls b, b, between the central chamber A and the calcining
chambers B, B, into the external walls c, c, of the latter, so as whilst forming
conduits for the beated air to act as stays and afford support to the said walls.
The tubes C, C, which are open at their inner end d to the central chamber A
and closed at their outer end e by or in the external walls c, c, of the calcining
chambers B, B, are perforated at their lower side with holes f in such a manner
that the heated air which passes from the central chamber A along the tubes C, C,
escapes through the said holes f, and is thus diffused or distributed among the
material, which has been introduced into the calcining chambers B, B.
The material is thus calcined at the lower part of the kiln without being brought
into contact with the products of combustion, and is drawn or discharged in any
convenient manner through shoots or inclined passages D below, provided with
external sliding doors, not shewn in the Drawings, the heated air ascending at the
same time partially dries the material at the upper part preparatorily to the descent

page_text: of such material to take the place of the lower portion as it is calcined and drawn,
fresh material being then supplied from above, so that the chamber is always full,
the whole of the heat is utilized under the most advantageous conditions, and the
operation proceeds continuously without any intermission or interruption in the
working of the kiln.
It is obvious that in lieu of making the kiln double, as hereinbefore 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 chamber may be divided by partitions so as to form compartments
capable of being worked separately or in any combination as required.
Having now described and particularly ascertained the nature of my said Inven-
tion, 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,―
Calcining gypsum, lime, and other like materials by the employment of a blast
of heated air in a kiln constructed with a calcining chamber or chambers, having
perforated tubes extending across the said chamber or chambers, and arranged in
such a manner that the material to be calcined introduced into the calcining cham-
ber or chambers from above surrounds the said perforated tubes which convey the
heated air into and diffuse and distribute it among such material, the calcined
portion of the material being drawn from below, and its place supplied by the
upper portion which has become heated and partially dried, and which in its turn
is replaced by fresh material introduced from above, all substantially as herein before
described.
In witness whereof, I, the said Edward Jaines Atkinson, have to this my
Specification set my hand and seal, the First day of July, One thousand eight
hundred and seventy ninc.
EDWARD JA8. ATKINSON. (L.S.)