Improvements in or relating to the Manufacture of Cement and the Means employed therefor.
Year: 1890

page_text: Date of Application, 18th Nov., 1890
Complete Specification Left, 18th Sept., 1891-Accepted, 24th Oct., 1891
Improvements in or relating to the Manufacture of Cement and the
Means employed therefor.
I, THOMAS ARNOLD of 1. Stanley Terrace, West Hartlepool, in the County of
Durham, Cement Maker, do hereby declare the nature of this invention to be as
follows:
My invention relates to the manufacture of cement and has for its object
improvements in the arrangement and construction of the kilns and drying chambers.
and drying flats with a view to economise or more fully utilize the heat generated
in burning the cement, which I employ not only for burning the cement but also in
the previous stages of drying the slurry and drying the bricks or moulds into which
it is made.
A further object of my invention is to provide special arrangements for admitting
air to the calcining kilns to facilitate the process of reducing the cement clinkers
to powder.
In my improved arrangements and construction of kilns, I employ coal in the
calcining kilns the products of combustion from which pass through another set of
kilns or chambers in which cement bricks are dried, leaving behind soot or uncon-
sumed carbon which lodges in the interstices between the bricks to be regenerated
into combustion by additional heat from the calcining kilns the products of combus-
tion ultimately passing under the drying flats or floors to dry the slurry sufficiently
to be formed into bricks.
The application of the heat to the different stages which make up the above
described process is so adjusted or balanced that, when the slurry (which is exposed
and can be examined at any time) is sufficiently dried the cement in the calcining
kilns (which is enclosed therein and cannot be inspected), is also sufficiently burnt,
or in other words, the state of the slurry affords a reliable indication of the state of
the cement which is undergoing the final process of burning.
A further feature in my improved kilns relates to the means employed for regu-
lating the admission of air to the calcining kilns in such a manner that the combus-
tion can be either intensified or the cement clinkers be crumbled to powder by the
sudden admission of a large body of cold air upon them when in a state of incipient
fusion.
In carrying out my invention I will first describe how I apply my improvements
so that the unconsumed heat from the calcining kilns passes through the drying
chamber then under the flat or floor, on its way to the chimney. I provide as
much accomodation in the drying chambers as in the calcining kilns and arrange
them preferably side by side in two rows so that a communication exists between
cach calcining kiln and a corresponding drying chamber the drying flats or floors
are placed immediately beyond the drying chambers, the flues from which are led
under the drying flat to the chimney by this arrangement the products of combus-
tion from the calcining kilns are drawn through the drying chambers in which the
bricks are so lodged that all soot or unconsumed carbon is trapped in the interstices
thereof; the said products of combustion are then drawn underneath the drying
flat and into the chimney.
;
It will be understood that the relative positions of the calcining kilns drying.
chambers and drying flats or floors may be varied in many ways more or less
favourable for effecting the objects of my invention, and that the principles involved
in leading hot gases or products of combustion through a chamber. charged with

page_text: bricks or brickwork to the best advantage is, well understood as for instance by
placing the drying kilns or chambers at a higher level than than the calcining
kilns on the one hand and the drying flat on the other hand the currents of hot
gases will be siphoned and will.consequently have a greater tendency to impinge
upon all intercepting surfaces on their passage to the chimney. In order to bring
the escaping hot gases more effectually into contact with the cement clinkers at the
back part of the calcining kilns these kilns are constructed with sloping back walls.
The usual charging holes are provided in the upper part of each kiln.
My improvements for controlling the temperature of the calcining kilns consist
as follows:--Fire-holes are provided at the lower part of the front of each calcining
kiln controlled by cast iron sliding doors above which are provided a series of air
holes also under control for regulating the combustion. When sufficient heat is
carried over from the calcining kilns to the drying chambers, the soot or unconsumed
carbon previously lodged there between the interstices of the bricks is ignited and
the process of drying the cement bricks accelerated in consequence. An opening
controlled by a cast iron door is provided in the front of the calcining kilns of
sufficient area to suddenly admit a large body of cold air upon the cement clinkers
when in a state of incipient fusion with the result that the rapid contraction to
which they are subjected causes them to crumble to dust from which state the
cement can be more readily reduced to a marketable condition.
The drying flats or floors are divided by steel division plates into a series of
longitudinal trough shaped partitions which are charged with slurry which slurry
when sufficiently dried is divided into suitable lengths and placed in the drying
chambers and afterwards burnt, or the partly dried slurry can be made into
convenient sizes by any mechanical means as for instance an ordinary brick mill.
Dated this 17th day of November 1890.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the said Thomas Arnold.
COMPLETE SPECIFICATION.
Improvements in or relating to the Manufacture of Cement and the
Means employed therefor.
I, THOMAS ARNOLD, of 1, Stanley Terrace, West Hartlepool, in the County of
Durham, Cement Maker, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates to the manufacture of cement and to apparatus to be used
in connection therewith.
One improvement constituting a part of my invention consists in the arrangement
of the kilns, drying chambers, and drying flats with a view to economise or more fully
utilize the heat generated in burning the cement by which the heat which would be
wasted after burning the cement is used in the previous stages of drying the slurry
to be formed into the bricks or moulds for the drying chamber and of drying the
said bricks or moulds in the drying chamber to be afterwards calcined in the kiln.
A further improvement consists in reducing the cement clinkers to powder by
the sudden admission of cold air into the kiln when the clinkers are in a state of
incipient fusion for which purpose one or more sliding doors of large dimensions are
provided at the front of the kiln.
My improvements also relate to the means employed for regulating the tempera-
ture to which the cement clinkers are exposed in the process of calcination, which
temperature can be ascertained from the state of the slurry on the drying floor
which is dried by the waste heat from the drying chamber as it passes through flues
under the drying floor; or if the state of the slurry on the drying floor cannot be

page_text: taken as a sufficiently reliable indicator of the temperature of the calcining kiln, a
pyrometer may be used in the ordinary way. Kilns for calcining cement clinkers
as hitherto constructed when once charged must be left to themselves, and the
temperature to which the clinkers have been subjected during calcination can only
be discovered from the state of the clinkers themselves after they are discharged
from the kiln, and the temperature of the kiln cannot be regulated whilst the
process of calcination is in progress.
I effect my improvements in this respect by charging the fuel, which is preferably
coal, into the lower part of the furnace with air holes provided at a higher level
and controlled by sliding doors to admit the required quantity of air to support the
combustion which will produce the requisite temperature.
The invention is not limited to any precise form of apparatus so long as the above
described purposes of my invention arc effected, but convenient modes of construct
ing my improved apparatus are shown in the drawings in which Figure 1 is a part
sectional view of an apparatus constructed to manufacture cement in accordance
with my invention, and Figure 2 is a corresponding end view of the calcining kiln.
Figures 3, 4, 5 and 6 illustrate a modified form of the apparatus in which Figure 3
is a vertical section of the apparatus from the calcining kiln to the chimney and
taken on line X, X of Figure 4, which is a corresponding plan view with part of
the drying floor removed.
Figure
is a sectional view taken on line Z Z of
Figure 3. Figure 6 is the end view of the calcining kiln showing the position of
the door for charging the fuel and for admitting the air to support combustion and
to chill the clinkers.
Like letters of reference indicate the same parts in all the figures, a, is the calcin-
ing kiln, b, the drying chamber, c, the flues under drying floor d, and e, the chimney
which is illustrated in Figure 3, but omitted in Figure 1; for controlling the
temperature of the calcining kiln, fire holes fffare provided at the lower part of
the calcining kiln for charging in the coal upon the gratings and are furnished
with sliding doors for controlling the admission of air to support combustion; kis
a large opening through the end wall of the kila with a cast iron slide door lined
with fire brick to close up the kiln whilst the cement clinkers are being calcined;
when the clinkers are sufficiently calcined and in a state of incipient fusion, this
iron door is removed so that the cement clinkers are subjected to a chill by the
sudden admission of cold air into the kiln and are so constructed in consequence
as to readily crumble into powder. The brickwork m, below the sliding door 1,
is built up afresh each time the kiln is charged. The usual top charging holes n,
may be provided as shown in Figure 1 if required. I provide as much accommo-
dation in the drying chambers, as in the calcining kilns a, and arrange them
preferably side by side in two rows so that a communication exists between each
calcining kiln, and a corresponding drying chamber the drying flats or
floors d are placed immediately beyond the drying chamber b so that the flucs c are
led therefrom under the drying flat to the chimney. By this improved construction
of the apparatus the products of combustion from the calcining kilns are drawn
through the drying chambers in which the bricks are so lodged that all soot or
unconsumed carbon is trapped in the interstices thereof to become ignited as the
temperature increases, and so to accelerate the process of drying the bricks
preparatory to lodging them in the calcining chamber; the products of combustion
on leaving the drying chamber are drawn under the drying floor & through the
flues c and into the chimney.
:
It will be understood that the relative positions of the calcining kilns, drying
chambers and drying flats or floors may be varied in many ways more or less favour-
able for effecting the purposes of my invention, and that the principles involved in
leading hot gases or products of combustion through a chamber charged with bricks
or brickwork to the best advantage is well understood and requires no description
otherwise than as to its special application to the manufacture of cement in accord-
ance with my invention, as for instance referring to Figures 1 and 2 the drying

page_text: chamber b is placed at a higher level than the calcining kiln a on the one hand and
the drying floor d on the other hand, by which the currents of hot gases are siphoned
and consequently have a greater tendency to impinge upon all intercepting surfaces
on their passage to the chimney. When the apparatus is constructed in the form
shown in Figure 1, the back wall p is sloped in the manner shown, in order to bring
the hot gases into proper contact with clinkers lodged at the back of the kiln.
This form of the apparatus will be found convenient where the configuration of
the ground is suitable, but would be expensive in construction in cases where the
floor of the drying chamber would have to be raised to the higher level shown by
an artificial formation of the ground or by brickwork.
This objection will be overcome by the construction of the apparatus as illustrated
more particularly in Figure 3 by which a difference of level between the calcining
kiln, and the drying shed is obviated, the currents of hot gases being siphoned and
suitably distributed by the bridge o.
A further advantage in the modified construction of the apparatus is that the
calcining kiln a, and drying chamber b, are reversible, that is to say, can be used
as the calcining kiln and a as the drying chamber. In order to do this both
chambers are constructed alike as to fire holes and air holes and outlets plp lead
into the same channel 3. The fire holes and air holes are closed in the chamber
used as the drying chamber and the outlet to the chimney is closed in the chamber
used as the kiln. The construction of the apparatus has the advantage of saving the
removal of the bricks or moulds from the drying chamber to the kili, as the bricks
can be dried and subsequently calcined in the same chamber.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that
what I claim is :-
:
Firstly An apparatus for the manufacture of cement in which are combined
these several improvements, namely intercepting the waste heat and unconsumed
products of combustion which escape from the calcining kiln by passing them
through the drying chamber and under the drying floor; generating the combustion
in the calcining kiln so that the temperature to which the clinkers are subjected
may be regulated as required; the sudden admission of cold air into the kiln when
the cement clinkers are in a state of incipient fusion to make them easily reducible
to powder, all substantially as described with reference to the accompanying
drawings.
-
Secondly The arrangement and combination of parts constituting the improved
apparatus for the manufacture of cement by which the products of combustion
which escape from the calcining kiln are utilized by being passed through the drying
chamber and under the drying floor, substantially as and for the purposes as
herein before described and illustrated by way of example in the accompanying
drawings.
Thirdly The arrangement and combination of parts constituting the improved
apparatus for the manufacture of cement by which the products of combustion which
escape from the calcining kiln are so passed through the drying chamber, that any
soot or unconsumed carbon carried over is lodged in the interstices of the bricks or
moulds which are being dried, substantially as and for the purpose as hereinbefore
described.
Fourthly In apparatus for the manufacture of cement, the use and construction
of a calcining kiln in which the fuel is charged into the kiln and air so admitted for
supporting the combustion of the said fuel that the temperature of the kiln may be
regulated as required, substantially as hereinbefore described.
-
Fifthly In the manufacture of cement, the reduction of the clinkers to powder
by subjecting the said clinkers to a sudden chill when in a state of incipient fusion,
substantially as and for the purpose as hereinbefore described.
:-
Sixthly The particular arrangement and construction of parts, constituting an

page_text: apparatus for the manufacture of cement as hereinbefore described and illustrated
in Figures 1 and 2.
:-
Seventhly The particular arrangement and construction of parts constituting
an apparatus for the manufacture of cement as hereinbefore described and illustrated
5 in Figures 3 to 6 inclusive of the accompanying drawings.
Dated this 17th day of September 1891.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.