Improvements in or relating to Apparatus for the Manufacture of Cement.
Year: 1899

page_text: Date of Application, 11th Nov., 1899
Complete Specification Left, 11th Sept., 1900-Accepted, 11th Dec., 1900
PROVIDIUNAL DITUITIVATION,
Improvements in or relating to Apparatus for the Manufacture of
Cement.
We, JOHN CUBITT GOSTLING, College Hill Chambers, Cannon Street, in the
City of London, Cement Manufacturer, JoHN HAZELL FRASER, of the Firm of
John Fraser & Son, Millwall, in the County of London, Engineers, and ROBERT
BOOTH, of 110, Cannon Street, aforesaid, Engineer, do hereby declare the nature
of this invention to be as follows:
-
are
This invention has reference to improvements in or relating to that kind of
apparatus for manufacturing cement according to which the slurry from which
cement is to be made is dried and burnt whilst passing through a rotating
slightly inclined cylindrical kiln through which flame and hot gases
caused to pass in an opposite direction, the slurry entering the kiln at the upper
and cooler end and the dried and burnt cement material escaping from the
lower and hottest end. When the kiln is heated by the burning therein of a
mixture of combustible gas or vapour and air delivered into the lower end of
the kiln direct from a gas or vapour producer and the external atmosphere
respectively, as heretofore usual, it has been found in practice that the tempera-
ture of combustion of the gas or vapour is not sufficiently high to effect the
diving and burning of the cement material in an advantageous manner when
using the long kilus, now commonly adopted, and this invention has for object
to obviate this disadvantago and enable a very high temperature of combustion
to be obtained in a convenient and economical manner.
For this purpose there is provided in proximity to the lower discharging end
of the kiln, an air heating device so constructed and arranged that the hot burnt
cement material will be brought into contact therewith immediately upon its
leaving the kiln and before it has been materially reduced in temperature, so
that air forced through the said air heating device on its way to the kiln to
effect the combustion of producer or other gas or vapour therein will be raised
to a high temperature and so enable a very high temperature of combustion to
be attained which ensures that the issuing burnt cement material brought into
contact with the air heating device shall have been efficiently burnt.
According to one arrangement, the lower end of the cylindrical kiln is
mounted to rotate in a normally stationary hood or combustion chamber pro-
vided at its lower side with a discharge opening for hot burnt cement material,
and at its rear end with a nozzle, which may be of double conical shape, through
which hot combustible gas or vapour and heated air are caused to pass. Below
the discharge opening in the hood is a chamber wherein is arranged an air
heating device comprising two or more boxes or conduits each formed for
example of a pair of corrugated metal plates arranged at a short distance apart
and preferably more or less vertical, or of horizontal or vertical pipes or cylin-
ders, the boxes, pipes or equivalent devices being each connected at its ends to
junction pipes one
BONIO of which is 01' are connected to an
01

page_text: air supply pipe into which air is forced by a fan or other suitablo
means, and the other or others of which is or are connected to an air delivery
pipe by which the air is led to the hot air inlet of the kiln where it becomes
mixed with the producer or other combustible gas or vapour lo be burnt. The
air boxes, pipes or equivalent and some of the junction pipes or passages con-
nected thereto, may be provided, if necessary, with partitions or divisions, the
arrangement being such that air forced into one part of the junction pipes at
one end of the heating device may flow simultaneously through the lower por
tions of the several air boxes pipes or equivalent into the junction pipes at the
other end of the device from which it will flow backward through the upper
portions of the several air boxes, pipes or equivalent into another portion of the
first mentioned junction pipes from which it passes into the air delivery pipe and
thence to the kiln. As will be obvious the construction may be such that the
air may be thus caused to flow backward and forward in a zig-zag manner
several times before it is finally conducted to the inlet nozzle of the kiln. The
corrugated air heating boxes or equivalent air heating devices are or may be
inclined to one another so as to form between them spaces or compartments
that increase in cross sectional area from top to bottoni. Means are provided
for delivering the hot burnt material from the kiln into the upper ends of the
several spaces or compartments, and means are or may be provided for with-
drawing the material from the bottom of the said spaces or compartments into
suitable trucks or other receptacles for carrying it away; or the withdrawal of
the material may be effected by haud-raking. The arrangement is such that
the spaces or chambers between the boxes or equivalent devices can be filled
with hot burnt material which will be caused to gradually descend through the
said spaces or chambers and raise the air-heating apparatus, and the air flowing
therethrough to the kiln, to a high temperature.
The form and details of construction of the air heating device can obviously
be variously modified.
The combustible gas for use in the kiln is or may be obtained from an
ordinary gas producer delivering into a gas main from which it is led through a
suitable passage to the gas and air inlet nozzle of the kiln. The hot air may
bo delivered through a centrally arranged pipe surrounded by the gas delivery
opening.
Improvements in or relating to Apparatus for the Manufacture of
Cement.
We, JOHN CUBITT GOSTLING, of College Hill Chambers, Cannon Street, in the
City of London, Cement Manufacturer, JoHN HAZELL FRASER, of the Firm of
John Fraser and Son, Millwall, in the County of London, Engineers, and ROBERT
BOOTH, of 110, Cannon Street, aforesaid, Engineer, do hereby declare the nature
of this invention and in what manner the same is to be performed to be par-
ticularly described and ascertained in and by the following statement:-
This invention has reference to improvements in or relating to that kind of
apparatus for manufacturing cement according to which the slurry from which
cement is to be made is dried and burnt while passing through a rotating slightly

page_text: inclined cylindrical kiln through which flame and hot gases are caused to pass
in an opposite direction, the slurry entering the kiln at the upper and cooler
end and the dried and burnt cement material escaping from the lower and
hottest end. When the kiln is heated by the burning therein of a mixture of
combustible gas or vapour and air delivered into the lower end of the kiln
direct from a gas or vapour producer and the external atmosphere respectively,
as heretofore usual, it has been found in practice that the temperature of com-
bustion of the gas or vapour is not sufficiently high to effect the drying and
burning of the cement material in an advantageous manner when using the
long kilns, now being adopted, and this invention has for object to obviate this
disadvantage and enable a very high temperature of combustion to be obtained
in a convenient and economical manner.
For this purpose there is provided in proximity to the lower discharging end
of the kiln, an air heating device so constructed and arranged that the hot burnt
cement material will be brought into contact therewith immediately upon its
leaving the kiln and before it has been materially reduced in temperature, 80
that air caused to flow through the said heating device on its way to the kiln
to effect the combustion of producer or other gas or vapour therein, will be raised
to a high temperature and so enable a very high temperature of combustion
to be attained in the kiln which ensures that the issuing burnt cement material
brought into contact with the air heating device shall have been efficiently burnt.
In the accompanying illustrative drawings, Fig. 1 shows partly in longi-
tudinal and partly in side elevation, Fig. 2 in plan, and Fig. 3 in end view,
one arrangement of apparatus according to this invention. Fig. 4 is a hori-
zontal section on the line A A of Fig. 3, parts being removed. Figs. 5, 6 and 7
show respectively in end view, side view and plan, the air heating device shown
in Fig. 1. Fig. 8 is a side view, Fig. 9 an end view, and Fig. 10 a section on
the line B B of Fig. 8, showing a modified construction of air heating device.
According to the arrangement shown, the lower end of the cylindrical kiln 1
is mounted to rotate in a normally stationary hood or combustion chamber 2 pro-
vided at its lower side with a discharge opening 3 for hot burnt cement material.
and at its rear end with a nozzle 4, which may, as shown, be of double conical
shape, through which hot combustible gas or vapour and heated air are caused
to pass and which in effect constitutes a preliminary mixing and combustion
chamber. Below the discharge opening 3 is a chamber wherein is arranged
an air heating device comprising boxes or conduits G each formed for example.
as shown in Figs. 1, 5, 6 and 7, of a pair of corrugated metal plates 7 arranged
at a short distanco apart and preferably more or less vertical, or, as shown in
Figs. 8, 9, and 10, of vertical pipes 7", (or cylinders), the boxes. pipes or equiva-
lent devices being connected at their ends to junction pipes 9, 9 of which 9 are
connected to an air supply pipe 10 (Figs. 5, 6 and 7) through which air is
caused to flow by a fan 11 (Figs. 1 & 2) or other suitable means, and the
others 9 are connected to an air delivery pipe 12 by which the air is led to the
hot air inlet of the kiln where it becomes mixed with the producer or other
combustible gas or vapour to be burnt. The air boxes, pipes or equivalent and
some of the junction pipes or passages 9, 9, connected thereto, may be provided,
if necessary, with partitions or divisions, as shown at 13 in Figs. 3, 5 and G,
so that air caused to flow into one part of the junction pipes at one end of the
heating device may flow simultaneously through the lower portions of the several
air boxes, pipes or equivalent into the junction pipes or connecting passages at
the other end of the device from which it will flow through the upper portions
of the several air boxes, pipes or equivalent into another portion of the first
mentioned junction pipes from which it passes into the air delivery pipe 12 and
thence to the kiln. As will be obvious the construction of the air heating
device may be such that the air will be thus caused to flow backward and forward
in a zig-zag manner several times before it is finally conducted to the inlet
nozzle 4. In the arrangement shown in Figs. 1, 5, 6 and 7, the air enters the

page_text: lower junction boxes 9, flows forward through the lower portions of the boxes
to the opposite ends thereof, then rises and flows back to the opposite end of the
boxes to the junction boxes 9 and thence to the delivery pipe 12, and in the
arrangement shown in Figs. 8, 9 and 10, the air enters the lower junction
pipes 9, flows upward through the pipes 7 to the upper junction pipes 9 and
thence to the air delivery pipe. In each case the air will be brought into
intimate contact with a large heating surface whereby it will be raised to a
high temperature.
The corrugated air heating boxes 6 or equivalent air heating devices are or
may be inclined to one another as shown in Fig. 1, so as to form between them
spaces or compartments 13 that increase in cross sectional area from top to
bottom. Means such as a hopper 14 and a deflector 15 are provided for deliver-
ing or guiding the hot burnt material from the kiln into the upper ends of the
several spaces or compartments 13, and means are or may be also provided for
withdrawing the material from the bottom of the said spaces or compartments
into suitable trucks 16 or other receptacles for carrying it away; or the with-
drawal of the material may be effected by hand-raking. In the example shown
in Figs. 1 to 4, there is provided below each compartment 13, a plate or shelf 17
on to which the burnt cement material falls and over which reciprocates a
slide 18 having inclined or bevelled sides 18 which, as the slides move to and
fro, pushes the material off the plate 17 and causes it to fall into the trucks 16
helow. The slides 18 are reciprocated automatically from the rotary kiln 1.
For this purpose, they may, as shown, be connected by a common link 19 to n
lever 20 fixed to a rock shaft 20 provided with a second lever arm 21 which is
connected to the lower end of a rod 22 the upper end of which is connected to
one arm 23 of a lever pivoted at 23" the other arm 24 of which is arranged in
the path of one or more cams 26, (two are shown) on the rotary kiln 1. The
lever arm 23 is connected by a rod 27 to a lever arm 28 pivoted at 28* and
extending into the path of the cams 26. As will be seen, with this arrange-
ment, the lever 23-24, will be moved alternately in opposite directions by each
cam 26, and through the rod 22. lever arms 20 and 21, and link 19, will cause
the alides 18 to move to and fro over the plates 17. With the arrangement
described, the spaces or chambers 13 between the boxes or equivalent devices
can be filled with hot burnt material which will be caused to gradually descend
through the said spaces or chambers and raise the air-heating apparatus, and
the air flowing therethrough to the kiln, to a high temperature.
The form and details of construction of the air heating device can obviously
be variously modified.
The combustible gas for use in the kiln is or may be obtained from an
ordinary gas producer delivering into a gas main 29 from which it is led through
a suitable passage 30 (Fig. 1) to the gas and air inlet nozzle or mixing device 4
of the kiln. The hot air may be delivered through a centrally arranged pipe 31
that is or may be endways adjustable and is surrounded by the gas delivery
opening 32.
We are aware that it has heretofore been proposed to heat the air used for the
combustion of gas or vapour in cylindrical kilns of the kind referred to, by
Dassing the air through regenerators heated by the products of combustion escap-
ing from the upper or feeding end of the kiln, and also by causing the air to
flow over the surface of the burnt cement material whilst the same is passing
through a tunnel or chamber leading from the delivery end of the kiln and
therefore we do not broadly claim the use of heated air for the combustion of
gas or vapour in kilns for the manufacture of cement. With such earlier
arrangements however it is not practicable to heat the air to a very high tem-
perature, because, in the first case, the escaping products of combustion, especially
with long kilns, are comparatively cool, and in the second case, only a compara-
tively small proportion of the air is brought into direct contact with the surface
of the escaping burnt cement material which moreover would not be at a very

page_text: bigh temperature. With our apparatus on the contrary, the air is thoroughly
heated to a very high temperature by the heat of the burnt cement material
immediately on its exit from the burning chamber of the kiln with the result that
a very high temperature of combustion is attained within that chamber so that
the slurry fed into the kiln will be thoroughly dried and burnt in an advan-
tageous manner when using long kilns, and the burnt cement material will leave
the kiln at a much higher temperature than usual, which, in turn, causes the
air to be heated to the higher temperature required according to this invention
to enable the drying and burning of the cement material to be effectually carried
out. By the present invention rotary kilns of from sixty to one hundred feet in
length can be worked in an advantageous manner.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. In apparatus of the kind herein referred to for the manufacture of cement,
the combination with the rotary kiln and gas or vapour supply apparatus, of
an air heating device so constructed and arranged that the hot burnt cement
material will be brought into contact therewith immediately upon its leaving the
kiln and before it has been materially reduced in temperature and air caused
to flow through the said heating device on its way to the combustion chamber
of the kiln will be raised to a high temperature, substantially as herein described
for the purpose specified.
2. Apparatus of the kind referred to in the preceding claim for the manufac
ture of cement, wherein the air heating device comprises boxes, pipes or equiva-
lent means arranged within a chamber below the discharge opening for the burnt
cement material so as to be heated externally by the direct contact therewith
of the hot escaping burnt cement material and through which air supplied to
the kiln will be caused to flow and be brought into effective and intimate con-
tact with the inner surface of the said boxes, pipes or equivalent, substantially
as herein described.
3. In apparatus of the kind herein referred to for the manufacture of cement,
the improved air heating arrangements constructed, arranged and operating
substantially as herein before described with reference to the drawings annexed.
Dated this 11th day of September 1900.
Dated this 11th day of September 1900.
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.