Improvements in the Manufacture of Portland Cement and similar Materials, and in Apparatus therefor.
Year: 1891

page_text: Date of Application, 8th July, 1891
Complete Specification Left, 8th Apr., 1892-Accepted, 2nd July, 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Portland Cement and similar
Materials, and in Apparatus therefor.
I, THOMAS HESKETH LODGE of Normanby in the County of York, Analytical
Chemist, do hereby declare the nature of this invention to be as follows:-
This
My invention relates to improvements in the manufacture of Portland cement,
and materials of a similar nature and also in apparatus therefor, and has for its
object a greater economy of labour and fuel, and the use of a compact apparatus
for the purpose.
In carrying my invention into effect I employ that kind of kiln
known as a
running kiln," covered in at the top by an arch or arches, within
which is constructed an inclined platform of burnt fireclay or other refractory
material, said platform being hereinafter called the pre-heating incline.
pre-heating incline is preferably provided with perforations or draught holes
through which the hot waste gases from the kiln can pass in a horizontal or
approximately horizontal direction. A hole, or holes is, or are pierced in the
crown or crowns of the arch or arches above the aforesaid incline, for the purpose
of allowing the material, from which cement or the like is to be made, to fall on
the pre-heating iucline so that it may be heated by the hot waste gases passing
through in a horizontal or approximately horizontal direction. A hopper, provided
with an air or draught-tight lid, and placed above the arch or arches, contains a
charge of the aforesaid material; and a trap door or equivalent device, above the
hole or holes in the arch or arches, retains the contents of said hopper until it is
required to renew the charge of dried slip or slurry or other cement making
material upon the pre-heating incline; this is done when the previous charge has
been moved forward towards the kiln.
.
The hopper is preferably constructed to hold sufficient material to form a
maximum.charge for the kiln, and the upper edge is furnished' with a trough or
channel running round it, which trough or channel is filled with powdered cement
making material or other suitable substance. The door or cover is also furnished
with a projecting rim which dips into the trough or channel before mentioned, and
sufficiently seals the joint.
The trap door; or equivalent which retains the contents of the hopper is mounted
upon a spindle to which is attached a lever, hereinafter termed the hopper lever.
This engages with a suitable catch when the door is closed, a counter weight or
balance is also attached to the hopper lever in such a manner and of such weight
as to close the trap door and cause the lever to be held by the catch auto-
natically when the hopper is empty. Ropes are attached to both the catch and
lever and these passing over suitable pullies are carried to any convenient place
upon or about the kiln so that when the weight of the material in the charged'
hopper presses against the trap door and against the action of the counter weight,
the workmen inay by manipulating the ropes regulate the speed of the discharge.
If it be necessary to cause the aforesaid ropes to pass into an air-tight or draught-
tight chamber instead of the hereinafter mentioned open charging floor, I attach
pistons or plugs thereto, which, working within.suitable tubes or pipes, effectually
prevent leakage when the ropes are operated. I do not however confine myself to
the use of the trap door aforesaid, but may effect the charging and regulation of the
material upon the pre-heating incline by means of suitable holes provided with
draught-tight doors in the crown of the arch.
At the base of the pre-heating incline I provide passages or flues formed of
burnt fire clay or other suitable material, so that if any of the aforesaid perforations
become.clogged there is still a passage or exit for the hot waste gases. The roof
•

page_text: of these passages projecting towards the kiln prevents the dried slip from sliding off
the pre-heating incline when in a state of rest. The entrance to said passages or
flues dipping toward the kiln, and also being at a higher level than the upper
pre-heating platform hereinafter to be described, the workmen can by means of
rakes or other tools, keep them clear. In those cases where the pre-heating incline
is not perforated, said passages or flues afford means for a free diaught.
Directly opposite the before-mentioned pre-heating incline, on the other side of
the kiln and outside of the same, is situated a workmans floor or charging room
hereinafter called the hot charging floor. This is placed at such a height that
the workmen standing upon it, can, by means of rakes or other iron tools, such
tools being passed through an opening or openings, furnished with suitable doors,
reach to the pre-heating incline, and also to both of the pre-heating platforms, for
the purpose of moving the cement making material in the manner hereinafter
described.
By making the pre-heating incline sufficiently large and leaving the cement
making material upon it a sufficient length of time the said material can be
raked into the kiln to be burnt without any subsequent pre-heating. But as it
is advantageous to turn the cement making material over so as to expose fresh
surfaces, I prefer using in addition horizontal pre-heating platforms or in some
instances one platform for that purpose.
I prefer using two pre-heating horizontal platforms an upper one and a lower
ope of burnt fire clay, and each supported by an arch of burnt fire clay. Each
platform can be made large enough to hold a full charge for the kiln, or can be
made to hold any convenient quantity, but, as I wish to reduce the area of each
platform, I prefer each of them to be of such a size as will hold only half a charge.
The upper horizontal pre-heating platform is situated at the base of the pre-
heating incline and nearly reaches to the centre of the kiln. The lower horizontal
pre-heating platform is placed in the centre of the kiln upon the summit of the
wall of the kiln, which wall divides the kiln into two parts. To reduce the amount
of breakage in the cement making material it is preferable that the two pre-heating
platforms be as close together as is compatible with the permission of a free egress
of the hot waste gases from the kiln. Whenever the pre-heating platforms are
denuded of the cement making material, in order to recharge the kiln, the said
platforms are covered by raking a sufficient quantity of material from the lower
part of the pre-heating incline, and heaping it up upon each platform into a shape
resembling a triangular prism. The apex of the heap upon the lower pre-heating
platform is placed or formed a few inches away from the centre of the kiln, nearer
to the men using the rakes; and the edge of the upper pre-heating platform not
quite reaching as far as the centre of the kiln, it follows that by raking off a
portion of the cement making material gently, it-will fall upon the nearest slope
of the heap upon the lower pre-heating platform, and from thence it will fall into
that half of the kiln immediately under or contiguous to the upper pre-heating
platform. It also follows that if another portion is raked off the upper pre-heating
platform with a sufficiently violent jerking motion, it will ultimately be projected
into that half of the kiln furthest from the upper pre-heating platform.
repeating these two motions of the rakes, each half of the kiln can receive an equal
share of the cement making material. If on the other hand it is desired to place
in that half of the kiln nearest to the upper platform, the whole of the heap upon
the upper pre-heating platform, the aforesaid gentle motion only is used; or, by
quick jerking motions the heap can be charged into the other half of the kiln,
namely that further away from the upper pre-heating platform.
By
The heap of cement making material upon the lower pre-heating platform is then
raked into the two halves, or one half if so desired, of the kiln in such a manner as
to cover those parts of the fuel not previously covered by the cement making
material off the upper pre-beating platform.
The above methods of charging are applicable to kilns having pre-heating
platforms which are only large enough for each to hold half a charge. When the

page_text: pre-heating platforms are each large enough to hold a full charge, I prefer raking
the heap upon the lower pro-heating platform into the two halves of the kiln,
re-covering it by raking the contents of the upper platform on to it, and leaving it
there to get hot for the next charge. The upper platform is then re-covered by the
cement making material from the pre-heating incline.
The charge of hot cement making material, newly charged into a kiln, can be
levelled or made to assume other formations by means of rakes or other iron tools
used through any, or all four of the hereinafter mentioned hot fuel charging doors..
The kiln is provided with the usual bars at the bottom, supporting the clinker,
and the said bars are opened at the intervals of charging in the usual manner.
When the pre-heating incline and platforms are re-covored, and the kiln has
received its charge of hot cement making material and fuel, it can be restored to
full operation again by opening the damper or dampers.
I prefer having the floor upon which the clinker falls to be of such a height that
the said clinker can be made to fall into the clinker waggons by gravitation.
The kiln is provided with the usual openings, furnished with doors, through
which bars can be inserted to loosen up the charge and break down adhering
clinker.
The kiln may be square, elliptical, circular or in any suitable horizontal section,
but preferably of circular formation exteriorly. The main lower part of the interior
I also prefer to be circular.
At that part of the interior which will ultimately be about nine feet below the
surface of the hot glowing clinker, I construct an arch dividing the kiln into two
parts, the thrust of the arch being received by a hoop or strap upon the exterior of
the kiln. Upon this arch I build a wall containing gas flues, furnished with exit
ports for the gas, and over the gas flues I erect or place two pairs of retorts, or any
convenient number, preferably made of fire-clay. These are placed at a level
which will be just above the surface of the hot glowing clinker in the kiln. In
ordinary gas works a cracked or leaky retort will cause a heavy loss, but in this
case a portion of the gas made is used as fuel in the kiln. A moderate escape of
gas into said kiln is not of great importance, and enables me to use retorts of
economical construction as follows, that is to say.
.
Upon the brickwork, above the before mentioned gas flues, are laid the ordinary
flat tiles generally used for the bottoms of built retorts, and two walls of suitable
height are built thereon, laid in fireclay with, a transverse central dividing wall.
Upon these walls are placed two ordinary gas retorts of burnt fireclay, the bottom
of each retort forming the roof of that immediately beneath it, and so placed that
the ends of said upper pair of retorts are over the ends of the lower pair. Each
retort is of sufficient capacity to hold a maximum charge.
Upon the top of the said upper pair is built the lower pre-heating platform herein-
before described.
Although I prefer the above described method of arranging the retorts, I may
use any other suitably constructed retorts and may vary the arrangement thereof..
Each retort is provided with a mouthpiece and lid, and also with an ascension
pipe, and dip pipe of ordinary or any suitable construction. The dip pipes dip into
a short section of hydraulic main, and from thence the gas is conducted through
suitable scrubbers and purifiers to an ordinary gas holder or may be conducted
directly by means of suitable pipes and valves to the gas flues. In the case of
using a gas holder the gas may be conveyed from thence to any part of the works
for heating and lighting purposes, or for motive power. The retorts may be
charged by shovels in the ordinary way, but preferably by means of a portable
scoop, which is mounted, in a novel manner, upon a detachable carriage. Said
carriage is provided with two front wheels and a swivelling trailing wheel. The
frame of the carriage consists of two vertical frames, carrying an upper and a
lower pair of cross bars, the upper set supporting the scoop at the level of the
upper retorts, and said lower bars serving the same purpose for the lower retorts.
A shoulder is formed upon that part of the shank of the scoop farthest from the

page_text: shank's crossbar; and between said shoulder and the scoop, a hinge and pin is
fitted with a cord or the like attached to the crossbar. When it is desired to push
a sooop into a retort, on withdrawing the pin, by the act of lifting the handle
upwards the hinge is thrown back and said scoop is free to enter the retort. I may
fill the scoops in the ordinary manner by means of shovels, or I may use a special
form of coal bunker for that purpose. Said bunker is preferably provided with a
conical bottom so that all the coal or any carbonaceous fuel I may wish to use, will
fall into the scoop filler by gravitation. The scoop filler for "lumpy "fuel may be
in the form of a shoot, provided with ordinary flap doors but for "small" coking
coal, the usual kind used in cement factories, or for inall fuel, I prefer it being
made as follows.
The scoop filler for small fuel is preferably made of cast iron shaped like three
quarters of a cylinder, and provided with a shaft. One lip of the elit is furnished
with a long steel knife, so that when it is revolved any small pieces of coal may be
cut that come between the edges of this knife and a fixed knife secured to the outer
frame of said scoop filler. The necessary force for cutting the coal is provided by
a lever and blocks, ropes or the 'like. When the revolution of the scoop filler has
caused the revolving blade upon its edge to pass the fixed knife, and the slot or
opening is downwards, the fuel contained therein can fall into the scoop. The handle
is returned to its first position in order to obtain a fresh supply for charging
another scoop.
To remove any obstruction such as a piece of rock or other hard substance which
may get between the blades, I provide a hole or holes fitted with caps in the end
of the scoop filler, through which hole or holes a bar can be driven to remove the
obstruction. -
(f
I preferably construct the bunker to hold a weeks supply of coal or fuel for two
kilns, and provide a power hoist and "tipping kibble .or skep" for filling it.
The tipping kibble may be filled in a well or pit into which the coal is discharged
from the trucks. Said well is provided with spouts having flap doors, or a similar
contrivance, so that the tipping kibbles can be filled without shovelling; and a
wall crane in connection with the hoist enables the operation to be done rapidly.
When the proper time has arrived for charging the kiln, the damper or dampers
is or are partly shut, and a retort which has been the longest charged is drawn and
the hot coke or fuel is allowed to fall upon a long scoop, which rests loosely upon
'a detachable two-wheeled carriage. The scoop is advanced under the mouthpiece
of the retort until half the contents of the retort are taken up by it, and, whilst the
coke or fuel is still hot, the scoop is swung round and discharged into the kiln
through one of the four doors provided for that purpose, situated at a somewhat
higher level than the coking floor. The hot coke or fuel is now spread evenly, or
in any other desired formation, upon the surface of the hot glowing clinker, by
means of rakes or other iron tools. That portion of hot fuel left in the retort is
now charged into the other half of the kiln by repeating the foregoing operations,
when the kiln will be ready to receive its charge of hot cement making material.
from the before mentioned pre-heating platforms.
I prefer to attach a removeable handle to the shank of the scoop to facilitate the
necessary manipulation of it on the limited space of the coking floor. In order to
keep the scoop from becoming overheated,. I prefer to make it of two separate
sheets of metal with an intervening space filled in with slag wool or the like, which
may be caused to absorb water for cooling purposes.
may place anti-friction rollers or wheels upon the door frames so that there
may be no unnecessary friction when putting the scoop in or withdrawing it. Tho
coal scoops hereinbefore described are filled and ready close at hand so that no time
may be wasted in charging the emptied retort while it is yet hot.
The foregoing operations of charging and drawing the retorts, and also charging
the hot fuel into the kiln, are performed upon a floor, which is preferably of fire-
proof construction, herein called the coking floor.
When it is desired to increase the quantity of heat passing to the drying

page_text: chamber or chambers, hereinafter to be fully described, I may do so by passing
more gas into the kiln, either by the flues in the dividing wall or by flues built
within the walls of the kiln having exit ports or orifices above the hot clinker, with
or without an auxiliary air supply from any source. This can be more easily
accomplished if the kiln walls are made thicker at the upper part, as follows. The
kiln, being of circular form at its lower part, is divided into two equal divisions by
the arch of the dividing wall built upon it. Said dividing wall is gradually increased
in thickness in proportion to its height, and the walls of the kiln are also increased
in the same manner, so that by rounding off the corners, each half will resemble in
transverse section the shape of a curtate cycloid.
The kiln can be used without the addition of a drying chamber for burning
natural cement stones or bricks of cement making material, as used in the "dry
process" but when the ordinary compound of chalk and clay is used in the semi-
fluid process I prefer drying it by the lot waste gases from the kiln, in a drying
apparatus of the following construction.
Upon piers of brick, concrete, stone, or other suitable material, I build an arch
supporting a drying apparatus in duplicate, at such a height that the floor of its lower
drying vault is at a higher level than the hereinafter described cold dried slip floor.
The hot waste gases from the kiln after passing through and under the before
mentioned pre-heating incline, pass into a pair of drying chambers by means of two
vertical flues. A pair of drying chambers is used so as to always have a passage,
for the hot waste gases, to the main flue when a chamber is being emptied, filled, or
repaired.
Both vertical flues are provided at their upper part with dampers of any
suitable kind, but preferably of cast iron plates which for convenience are made in
sections so as to be easily moveable. When it is desired to pass the hot waste gases.
through a chamber, I prefer to draw these dampor plate sections .completely out
and cover the aperture up by a plate having a projecting rim, which is pressed into
an under cut groove packed with asbestos. These damper plates can be pushed
across each vertical flue so as to cut off the supply of hot gases from the kiln when
it is desired to draw and charge a drying chamber.
Each chamber is built of bricks containing fixed metal drying plates arranged in
tiers and made so short from front to back that it can be filled and emptied from
the exterior of the chamber hereinafter called the drying plates compartment.
When it is anticipated that the temporature of the hot waste gases from the kila
will be high, I prefer to place the drying plates compartment over one or more
drying vaults, but preferably two, built of brick, which vault or vaults is or are in
communication with one or both of the beforo mentioned vertical flues. When
using two drying vaults, one is placed over the other and the hot waste gases are
conducted to the back part of the lower one, then upwards through a draught hole
to the upper one, and afterwards through the upper one into the drying plates
compartment by means of a draught hole at the front.
The draught passages between the drying plates, and between the top plate and
the roof, and also between the bottom plata and the floor, are not of the same
dimensions, but are so varied by projecting vertical plates, secured to that end of
each drying plate which is at the back of the chamber, that the wet slip is dried
upon them all at the same time.
The fixed drying plates, arranged in tiers within the drying plates. compartment,
are preferably constructed of cast iron and may be of any convenient number.
They are provided with ridges cast or otherwise formed upon their upper surface
running from front to back so that said ridges will offer no impediment to the
withdrawal of the dried slurry.
I have discovered that it is not necessary for the ridges to be as high as the full
depth of the slurry upon the plates and they may be placed apart at any suitable
distance, so as to cause cracks to be made which will form pieces of the required
transverse sectional area, thereby permitting the heat to more readily penetrate the
mass,

page_text: The drying vaults have each only one layer of slurry, which is placed upon a
floor made preferably of salt-glazed tiles, having ridges shaped and placed in a
similar manner as the ridges upon the plates.
The depth of the slurry in the vaults, and upon the roof of the upper vault, is
regulated by the height of detachable bricks, or other forms of burnt fire clay,
laid in or luted by thick slurry.
The depth of the slurry upon the plates is regulated by the depth of detachable
angle-irons, which fit into horizontal grooves, cast in, or otherwise formed at the
front edge of the plates, the depth of the slurry at the back of the drying plates
being regulated by vertical fixed plates cast or formed thereon.
It is desirable that no part of the slurry either upon the floors of the vaults or
within the drying, plates compartment shall be dried before another part; I
therefore cover the vaults with a thicker layer of slurry than the plates, and
moreover I make the depth of the slurry upon the front end of the plates greater,
by an inch or thereabouts, by lowering that part.
At a higher level than the top of the drying chambers is an ordinary slurry
reservoir and slurry main, provided with the usual slurry slides or other valves,
and with canvas pipes. and caps for each chamber. I prefer the handle of each
slide to be a double lever provided with ropes carried over pullies to the front of
the chamber so that I can regulate the flow of the slurry without being upon the
chamber.
I prefer filling the chamber by allowing the semi-fluid slurry to fall from plate
to plate and finally into the drying vaults. This can be done by arranging them
in the following manner :
Although the plates may be of the same size, all their front ends and all their
back ends are not in the same vertical plane, but are placed in a zig-zag manner
so that the slurry from a plate can overflow on to a plate immediately beneath it,
fill that plate until it overflows at the other end, and in turn falls upon another
plate immediately beneath, and so on until all the plates are filled, and also the
Hoor of the drying plates compartment. From thence the slurry falls into the
upper drying vault, by way of the draught hole, filling it, and finally overflowing
into the lower vault by the draught hole at the back. To facilitate the filling and
levelling of the slurry a scraper of the usual kind is employed such as is commonly
used for such work.
When all parts of the chamber are filled and the cap replaced over the hole
through which the slurry is admitted, the hereinafter described doors are shut.
Then by opening the before mentioned plate dampere, at the front of the chamber,
and also by opening the hereinafter to be described swing damper at the back, the
hot waste gases will dry the slurry.
When the slurry is dried, the dampers are all shut. The chamber doors are
then opened, and the slurry is raked out from off the plates and floors of the
drying chamber, by rakes or other tools on to a floor placed over the kiln called
the cold dried-slip floor. This floor, with its beams and roof is preferably
supported by the piers of the drying chamber, and by a pair of pillars reaching
down to, and supported by a protruding part of the kiln walls immediately beneath
the coking floor.
In raking the dried slurry out of the chamber, I prefer to let the contents of
the vaults slide down short detachable inclined shoots, so as to lie near to the
chamber, and also prefer that the contents of the drying plates shall slide down
longer shoots so as to lie further away from the chamber. From this 'heap of
dried slurry the before mentioned hopper is filled from time to time as it becomes
empty.
The interior of each drying chamber may be lighted by any suitable illuminant
but preferably by coal gas.. I prefer lighting the drying plates compartment in
the following manner. Through a hole in the roof, fitted with a draught tight
cap, I suspend a vertical detachable gas tube. This is provided with a sufficient
number of gas burners, at the requisito intervals, to illuminate the floor and every

page_text: plate in the compartment. The upper part of the tube has a union in order to
couple the detachable tube to a cock, said cock being screwed to a gas supply
pipe. By another branch supply pipe, also furnished with a cock, the gas is
conveyed to the two vaults. Two smaller pipes are fitted to the said branch pipe,
and are also provided with unions and burners. These smaller pipes are convoyed
through holes in the side wall of the drying chamber, said holes being provided
with detachablo plugs. The burners at the back of the vaults are preferably
lighted simultaneously by ignited wax-tapers, fixed upon a two-armed long rod
pushed through one of the vaults. The burners at the back of the drying plates
compartment are preferably lighted through a hole in the roof of the chamber by:
ignited wax-tapers fixed upon a rod at such intervals that all the burners in the
compartment are lighted simultaneously..
The front parts of the chambers are provided with two different kinds of doors,
the drying vaults having hinged doors and the drying plates compartment having
a suspended door provided with wheels. The suspended door is constructed with
an outer plate preferably of corrugated galvanized sheet iron, and with an inner
plate preferably of sheet copper, with a layer of slagwool interposed between them
to reduce radiation of heat.
These two plates of the suspended door are rivetted to a frame made of angle
or channel iron, or any other rolled iron which will have, as a frame, a projecting
rim that can be pressed, into an undercut groove packed with asbestos.
This undercut groove is formed in a cast iron frame secured to the brickwork.at
the entrance to the compartment, the groove being turned outwards. The wheels
of the suspended door are run upon the web of, and between the flanges of a
channel iron rail spanning the distance between two pairs of drying chambers, so
that not only can the door be wheeled away from the front of the chamber, but cau
also be moved a few inches transversely. Also a further amount of transverse
notion can be given by having long axles to the wheels. In this way sufficient
clearance will be given between the chamber and the door.
The doors of the drying vaults below the drying plates are hinged to a frame
and are constructed as hereinbefore described namely with slag wool and with a
projecting rim pressing into an undercut groove packed with asbestos but
preferably having fire clay tiles upon their inner side.
The damper which regulates the passage of heated gases from the kiln is
similarly caused to fit draught tight, and is provided with a shaft or spindle to
which is attached a long lever operated from the exterior of the drying chamber.
The damper is retained open by a tripping lever arranged to hold the long lever
before mentioned. Two other levers are attached to the tripping lever, one
carrying a counterweight, and the other placed so that the fall of a weight upon it
causes the said tripping lever to release the damper lever. A rope attached to
Baid damper lever passes over suitable pulleys, at the side of the drying chamber,
to the coking floors.so that the men stationed there, and also those stationed at the
drying chambers, may regulate it. The weight, which is arranged to fall upon
and release the tripping lever mechanism before mentioned, is retained by a cord,
with a ring pulling upwards against a smooth pin, upon a spindle, which passes in
an air tight manner through and into the drying chamber, where a second crank or
lever is held, by a short length of chain and a piece of lead or other fusible wire,
against the tension caused by the suspended weight. The fusible wire is imbedded
in wet slip, and thus cannot fuse and so release the weight and close the damper,
until said slip is dried. This device is intended as a precautionary measure only
to prevent over-heating, and need not be brought into requisition if ordinary
attention be paid to the drying chambers.
The products of combustion are in this apparatus finally cooled by contact with
the wet slip in the drying chambers so as to be practically useless in creating a
draught by connection unless a chimney of great height be employed. To obviate
this I employ an exhaust fan with a water cooled spindle, and driven by a gas
engine or other suitable motor to create a partial vacuum in the main
111

page_text: order to still further cool the gases so that the vanes and casing of the fan may
not be injured, I employ a cooling chamber having a roof of iron plates. I also
roof the main flue with iron plates covered with slurry, the combined area being
sufficient for the purpose of such cooling.
To ensure efficient lubrication under these circumstances I form the fan spindle.
with two shallow grooves cut into it, and a water box made to fit them, and
running nearly to the centre of said spindle. A current of cold water is caused to
play upon the spindle and is received by the water box before mentioned, and
may be carried away by an overflow pipe to the water vessel of the gas engine or
to the wash mill.
-
That part of the spindle in the water box may also be provided with discs or
rings, in order to give more cooling surface.
If, by reason of a breakdown or atoppage, the fan is not in use, a steam jet
may be used, which is ordinarily covered by a lid, with a sand joint when not
required. Also when the fan is not in use I cover the discharge outlet of said fan
by a lid having a sand joint.
I may in some cases employ a draught regulator or governor, shaped like a
small gas holder working within a tank of water or mercury, balanced by weights
which may be taken off or added for purposes of adjustment. A double coned
weight attached to a screwed spindle regulates the travel of the holder vessel, by
adjusting the distance between said cones. The interior of the, holder vessel is
connected to the main flue, so that the partial vacuum therein may cause the
descent of said holder vessel under the weight of the atmosphere. A suitable
connection is established between the regulator and the motor driving the fan, so
that the speed thereof may be regulated according to the predetermined partial
vacuum in the main flue.
In order to prevent injury to the brickwork by an explosion within the gas flues
when the gas is first lighted at the gas exit ports in the kiln, I may before
admitting the gas, displace the air within the gas flues by admitting carbonic acid
gas, and when the carbonic acid gas has in its turn been displaced by coal
gas, I
then ignite the escaping coal gas at cach set of ports, by means of a small gan jet
having an independent air supply. This air supply to each igniter may come from
a fan or bellows, and conveyed through a tube. This also has an inner gas tube
provided with a burner, which burner is just within the air tube, but close to the
end of the air tubo..
I may use a portable apparatus for generating or storing the carbonic acid
gas.
I prefer keeping the coke charging doors, and also the hot slip charging doors,
draught tight in the same manner as the before mentioned chamber doors.
Dated this 8th day of July 1891.
FREDK. WALKER,
11, Furnival Street, Holborn, London, E.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Portland Cement and similar
Materials, and in Apparatus therefor.
I, THOMAS HESKETH LODGE of 23 Cleveland Street, Normanby in the
County of York, Analytical Chemist, 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 improvements in the manufacture of Portland cement t
and materials of a similar nature and also in apparatus therefor, and has for its
object a greater economy of labour and fuel and the use of a compact apparatus for
the purpose.
In order that my invention may be the better understood, I have appended four
•

page_text: sheets of drawings in which the figure on Sheet 1 is a side sectional elevation of
the kiln and drying chamber with apparatus connected therewith, and Sheet 2 is
an end view shewn partly in section. Sheet 3 shews a side view partly in section,
and Sheet 4 is a plan view, partly in section. Similar letters of reference indicate
corresponding parts throughout the several sheets.
In carrying my invention into effect, I employ that kind of a kiln known as. a
"running kiln" K Figs. 1. 2. 3. 4. covered in at the top by an arch or arches A
Figs. 1. 2. within which is constructed an inclined platform I Fig. 1 and 2 of
burnt fireclay or other refractory material, said platform I being hereinafter called
the pre-heating incline. This pre-heating incline is preferably provided with
perforations J Figs. 1. 2 and 4 or draught holes through which the hot waste
gases from the kiln can pass in a horizontal or approximately horizontal direction.
A hole H' Fig. 1 (or holes) is (or are) pierced in the crown (or crowns) of the
arch A (or arches) above the aforesaid incline I for the purpose of allowing the
material M Fig. 1 from which cement or the like is to be made, to fall on the pre-
heating incline I so that it may be heated by the hot waste gases passing through
in a horizontal or approximately horizontal direction. A hopper H' Figs. 1. 2. 3:
provided with an air or draught-tight lid L Figs. 1. 3. 4. and placed above the
arch or arches, contains a charge of the aforesaid material, and a trap door T'
Fig. 1. or equivalent device, above the hole H (or holes) in the arch A (or arches)
retains the contents of said hopper until it is required to renew the charge of
dried slip or slurry or other cement-making material upon the pre-heating
incline I, this is doue when the previous charge has been moved forward towards
the kiln.
The hopper H is preferably constructed to hold sufficient material to form a
maximum charge for the kiln and the upper edge is furnished with a trough T
Figs. 1 and 4 or channel running around it, which trough or channel is filled with
powdered cement making material or other suitable substance.
The door L or cover is also furnished with a projecting rim which dips into the
trough Tor channel before mentioned, and sufficiently seals the joint. The trap
door Tor equivalent which retains the contents of the hopper M' is mounted
upon a spindle T to which is attached a lever T' Figs. 2. 3. 4. hereinafter termed
the hopper lever. This engages with a suitable catch T' Fig. 3 when the door T'
is closed, a counter-weight To Figs. 2. 3. 4. or balance is also attached to the
hopper lever T in such a manner and of such weight as to close the trap door T'
and cause the lever to be held by the catch T automatically when the hopper is
empty. Ropes are attached to both the catch and the lever, and these passing over
suitable pullies T", T, T", Fig. 3 are carried to any convenient place upon
or about the kiln so that when the weight of the material in the charged hopper
presses against the trap door and against the action of the counter-weight the
workmen may by manipulating the ropes regulate the speed of the discharge.
The rope T' Fig. 3 is used to disengage the catch T' from the lever T¹; catch T'
having a counterweight to move it back again to its former position. The rope T
Fig. 3 is used to check the too rapid ascent of the lever T. The rope T" Fig. 3.
is used to raise the lever Tupwards and thereby fully open. (when needed) the.
trap door T Fig. 1 of the hopper H. If it be necessary to cause the aforesaid
ropes to pass into an air tight or draught tight chamber or partially air-tight
chambor over F Figs. 1. 3. 4. instead of the hereinafter mentioned open charging
floor attach pistons or plugs thereto, which working within suitable tubes Tie
Figs. 1 and 3. or pipes, effectually prevent leakage when the ropes are operated.
I do not however confine myself to the use of the trap door T¹ Fig. 1. aforesaid,
but may effect the charging and regulation of the material M2 Fig. 1. upon the
pre-heating incline by means of suitable holes provided with draught tight doors
in the crown of the arch. At the base of the pre-heating incline I provide
passages or flues F F F F F Fig. 1 and 2 formed of burnt fireclay or other suitable
inaterial, so that if any of the aforesaid perforations J Figs. 1. 2.-4. become
clogged there is still a passage or exit for the hot water gases. The roof of these

page_text: passages F F F F F projecting towards the kiln prevents the dried slip M³ Fig. 1
from sliding off the pre-heating incline I when in a state of rest. The entrance to
said passages or flues dipping towards the kiln, and also being at a higher level
than the upper pre-heating platform P¹ Fig. 1. 2. hereinafter to be described, the
workmen can by means of rakes or other tools, keep them clear. In those cases
where the pre-heating incline is not perforated said passages or flues F F F F F
afford means for a free draught.
Directly opposite the before mentioned pre-heating incline, on the other side of
the kiln and outside of the same, is situated a workman's floor F' Fig. 1. 3. 4. or
charging room hereinafter called the hot charging floor. This is placed at such a
height that the workmen standing upon it can by means of rakes or other iron
tools, (such tools being passed through an opening or openings D D Fig. 1 and 4
furnished with suitable doors) reach to the pre-heating incline I aud also to both
of the pre-heating platforms P1 P2 Fig. 1 for the purpose of moving the cement
making material in the manner hereinafter described.
By making the pre-heating incline I sufficiently large and leaving the ceinent
making material upon it a sufficient length of time the said material can be raked
into the kiln to be burnt without any subsequent preheating. But as it is advan-
tageous to turn the cement making material over so as to expose fresh surfaces,
I prefer using in addition horizontal pre-heating platforms or in some instances
one platform for that purpose. I prefer using two pre-heating horizontal platforms
an upper one P and a lower one P2 of burnt fireclay and each supported by an
arch of burnt fireclay. Each platform can be made large enough to hold a full
charge for the kiln, or can be made to hold any convenient quantity, but, as I wish
to reduce the area of each platform I prefer each of them to be of such a size
as will hold only half a charge. The upper horizontal pre-heating platform P¹ is
situated at the base of the pre-heating incline 1 and nearly reaches to the centre
of the kiln. The lower pre-heating platform P is placed in the centre of the
kiln upon the summit of the wall W Fig. 1(and retorts) of the kiln, which wall
divides the kiln into two parts. To reduce the amount of breakage in the cement
making material it is preferable that the two pre-heating platforms P₁ P be as
.close together as is compatible with the permission of a free egress of the hot
waste gases from the kiln." Whenever the pre-heating platforms P P are denuded
of the cement making material, in order to re-charge the kiln the said platforms
are covered by raking a sufficient quantity of material from the lower part of the
pre-heating incline I and heaping it up upon each platform into a shape resembling
a triangular prisun. The apex of the heap upon the lower pre-heating platform P
is placed or formed a few inches away from the centre of the kiln, nearer to the
men tising the rakes; and the edge of the upper pre-heating platform P¹ not quite
reaching as far as the centre of the kiln, it follows that by raking off a portion of
the cement making material gently, it will fall upon the nearest slope of the heap
upon the lower pre-heating platform P2 and from thence it will fall into that half
of the kiln K' Fig. 1. immediately under or contiguous to the upper pre-heating
platform P. It also follows that if another portion is raked off the upper pre-
beating platform P¹ with a sufficiently violent jerking motion, it will ultimately be
projected into that half of the kiln K' Fig. 1 furthest from the upper pre-heating
platform P. By repeating these two motions of the rakes, each half of the
kiln can receive an equal share of the cement making material. If on the other
hand it is desired to place in that half of kiln K₁ nearest to the upper platform
the whole of the heap upon the upper pre-heating platform, the aforesaid gentle
motion only is used; or, by jerking motions, the heap M Fig. 1. can be charged
into the other half K of the kiln, namely, that further away from the upper pre-
heating platform. The heap of cement making material upon the lower pre-
heating platform P' is then raked into the two halves K' K, (or one half if so
desired,) of the kiln in such a manner as to cover those parts of the fuel not
previously covered by the cement making material off the upper pre-heating
platform P

page_text: The above methods of charging are applicable to kilns having pre-heating!
platforms which are only large enough for each to hold half a charge. When the
pre-heating platforms are each large enough to hold a full charge, I prefer raking
the heap upon the lower pre-heating platform P2 into the two halves of the kiln,
re-covering it by raking the contents of the upper platform on to it, and leaving it
there to get hot for the next charge. The upper platform is then re-covered
by the cement making material from the pre-heating incline I. The charge of hot
cement making material, newly charged into a kiln, can be levelled or made to
assume other formations by means of rakes or other iron tools used through any,
or all four of the hereinafter mentioned hot coke charging doors C C C C Fig. 1
and 3. The kiln is provided with the usual bars B' Fig. 1. and 2. at the bottom,
supporting the clinker, and the said bars are opened at the intervals of charging in
the usual manner.
When the pre-heating incline I and platform P1 P2 are re-covered and the kiln
has received its charge of hot cement making material and fuel, it can be restored
to full operation again by opening the suitable damper or dampers Y Y Y Y
Figs. 1. 2. 4. I prefer having the floor X Figs. 1 and 2 upon which the clinker
falls, to be of such a height that the said clinker can be made to fall into the
clinker waggons by gravitation.
The kiln is provided with the usual openings X X etc. Fig. 1 and 3, furnished
with doors, through which bars can be inserted to loosen up the charge and break
down adhering clinker. The kiln may be square, elliptical circular or of any other
suitable horizontal section, but preferably of circular formation exteriorly. The
main lower part of the interior I also prefer to be circular.
At that part of the interior which will ultimately be about nine feet below the
surface of the hot glowing clinker, I construct an arch W dividing the kiln into
two parts, the thrust of the arch being received by a hoop or strap upon the
exterior of the kiln. Upon this arch I build a wall containing gas-flues G' G'
Fig. 1 and 2 furnished with exit ports G G Fig. 1 and 2 for the gas, and over
the gas flues I erect or place two pairs of retorts R R R R, Figs. 1. 2. 3. 4 or
any convenient number, preferably made of fire-clay. These are placed at a level
which will be just above the surface of the hot glowing clinker in the kiln.
In ordinary gas-works a cracked or leaky retort will cause a heavy loss, but in
this case a portion of the gas made is used as fuel in the kiln, a moderate escape
of gas into said kiln is not of great importance, and enables me to use retorts of
economical construction as follows, that is to say, upon the brick-work W, Figs. 1
and 2 above the before mentioned gas-flues, are laid the ordinary flat tiles generally
used for the bottoms of built retorts, and two walls R R* Fig. 1 of suitable
height are built thereon, laid in fire-clay with a central transverse dividing wall R'
Fig. 1. 2. 4. Upon these walls are placed two ordinary gas retorts R' R³
Fig. 1 etc. of burut fireclay, the bottom of each retort forming the roof of that
immediately beneath it, and so placed that the ends of said upper pair of retorts
are over the ends of the lower pair. Each retort is of sufficient capacity to hold
a maximum charge. Upon the top of the said upper pair is built the lower pre-
heating platform P' herein before described.
Although I prefer the above described method of arranging the retorts I may
use any other suitably constructed retorts and may vary the arrangement thereof.
Each retort is provided with a mouth-piece and lid, and also with an ascension
pipe aud dip pipe of ordinary or any suitable construction. The dip pipes dip into
a short section of hydraulic main Go Fig. 3 and from thence the gas is conducted
through suitable scrubbers and purifiers to an ordinary gas-holder, or may be
conducted directly by means of suitable pipes and valves to the gas flues. In the
case of using a gas-holder, the gas may be conveyed from these to any part
of the works for heating and lighting purposes or for motive power. The
retorts may be charged by shovels in the ordinary way but preferably by means
of a portable scoop S' Figs. 1 and 2 which is mounted in a novel manner upon a
detachable carriage. Said carriage is provided with two front wheels $* S*

page_text: A
Fig. 1. & 2. and a swivelling trailing. wheel 8 Fig. 1 & 2. The frame of the
carriage consists of two vertical frames carrying an upper and a lower pair of cross
bars SS Fig. the upper set S supporting the scoop at the level of the upper
retorts, and said lower bars S7 serving the same purpose for the lower retorts.
shoulder is formed upon that part of the shank of the scoop farthest from the shank's
cross-bar; and between said shoulder and the scoop a hinge and pin S Fig. 1 is
fitted with a cord S Fig. 1 or the like attached to the cross bar. When it is
desired to push a scoop into a retort, on withdrawing the pin of S8 Fig. 1, by the
act of lifting the handle of the scoop upwards the hinge is thrown back and said
scoop is free to enter the retort.
may fill the scoop in the ordinary manner by
means of shovels or I may use a special form of coal bunker B2 Fig. 1. 2. 4. for
that purpose. Said bunker is preferably provided with a conical bottom so that all
the coal or any carbonaceous fuel I may wish to use, will fall into the scoop
filler B³ Figs. 1. 2 and 4 by gravitation. The scoop filler for the lumpy fuel may
be in the form of a shoot provided with ordinary flap doors but for small coking
coal, (the usual kind used in cement factories) or for small fuel; I prefer it being
made as follows. The scoop filler B for small fuel is preferably made of cast-iron
shaped like three-quarters of a cylinder, and provided with a shaft. One lip of the
slit is provided with a long steel knife B Fig. 2 and 4, so that when it is revolved
any small pieces of coal may be cut that come between the edges of this knife and
a fixed knife B' secured to the outer frame of said scoop filler. The necessary
force for cutting the coal is provided by a lever Be Fig. 1. 2. 4. and blocks, ropes
or the like.
When the revolution of the scoop filler has caused the revolving blade B*
upon its edge to pass the fixed knife B and the slot or opening is downwards, the
fuel contained therein can fall into the scoop. The handle B is returned to its
first position in order to obtain a fresh supply for charging another scoop. To
remove any obstruction such as a piece of rock or other hard substance which may
get between the blades, I provido a hole or holes fitted with caps in the end of the
scoop-filler through which hole or holes a bar can be driven to remove the obstruc-
tion.
I preferably construct the bunker to hold a weeks supply of coal or fuel for
two kilne, and provide a power hoist and tipping "kihble" or "skep" Q Fig. 1.
for filling it. The tipping kibble may be filled in a well or pit into which the
coal is discharged from the trucks. Said well is provided with spouts having
flap doors Q Fig. 1. or a similar contrivance so that the tipping kibbles can
be filled without shoveling. A wall crane Q' Fig. 1 in connection with the
hoist enables the operation of filling to be practically continuous. When the
proper time has arrived for charging the kiln, the damper or dampers Y'
and Y of N and N Figs. 1, 2 and 4 is or are partly shut (to prevent too
great a rush of cold air into the kiln) and a retort which has been the longest
charged is "drawn" and the hot coke is allowed to fall upon a long scoop S
Fig. 2 and 4 which rests loosely upon a detachable two wheeled carriage S
Figs. 2 and 4. The scoop S' is advanced under the mouth-piece of the retort
until half the contents of the retort are taken up by it, and whilst the coke
(or fuel) is still hot the scoop is swung round and discharged into the kiln
through one of the four doors CCCC Fig. 1 and 3 provided for that purpose,
situated at a somewhat higher level than the coking floor or F³ Fig. 2. 4. The
hot coke is now spread evenly or in any other desired formation upon the surface of
the hot glowing clinker by means of rakes or other iron tools. That portion of hot
coke or hot fuel left in the retort is now charged into the other half of the kiln by
repeating the foregoing operatione, when the kiln will be ready to receive its charge
of hot cement making material from the before mentioned pre-beating plat-
forms P P Fig. 1. I prefer to attach a removable handle S Fig. 4. to the shank
of the scoop to facilitate the necessary manipulation of it on the limited of
space
the coking floor For F³. In order to keep the scoop from becoming over heated,
I prefer to make it of two separate sheets of metal with an intervening space filled
in with slag-wool or the like, which may be caused to absorb water for cooling

page_text: "
purposes. I may place anti-friction rollers or wheels upon the door frames
of CCCC Figs. 1 and 3. so that thero may be no unnecessary friction when
putting the scoop in, or withdrawing it. The coal-scoops herein-before described'
are filled and ready close at hand so that no time may be wasted in charging the
emptied retort while it is yet hot. The foregoing operations of charging and
drawing the retorts, and also charging the hot fuel into the kiln, are performed
upon a floors Fand F3 which are preferably of fire-proof construction herein called
the coking floors. When a chamber is recently filled with wet "slip" it is desirable
to increase (for a time) the quantity of heat passing to the drying chamber or
chambers X X Fig. 2. etc. hereinafter to be fully described,, I may do so by
passing more gas into the kiln, either by the flues G' and G Figs. 1 & 2 in the
dividing wall W or by gas flues or pipes G' Fig. 1. built within the walls of the
kiln having exit ports or orifices G Fig. 1. above the hot clinker with or without
an auxiliary air supply G Fig. 1. from any suitable source, having the entrance G
Fig. 3. furnished with a regulator Q" Fig. 3. This can be more easily accomplished
if the kiln walls are made thicker at the upper part, as follows. The kiln being of
circular form at its lower part, is divided into two equal divisions by the arch of
the dividing wall built upon it. Said dividing wall is gradually increased in thick-
ness in proportion to its height and the walls of the kilu are also increased in the
same manner so that by rounding off the corners each half will resemblo in
transverse section the shape of a curtate cycloid. Air to support combustion is
warmed in the usual way by passing through the hot (burnt) clinker contained in
the lower part of the kiln, but the auxiliary air supply Gs Fig. 1. for the com-
bustion of the gas conveyed by the gas pipe (or pipes) G' Fig. 1. (above the hot
clinker), is warmed by passing backwards and forwards preferably in a zig-zag
manner in the wall of the kiln to the exit port G³. The kiln can be used without
the addition of a drying chamber for burning natural cement stones or bricks of
cement making material as used in the "dry process but when the ordinary
compound of chalk and clay is used in the semi-fluid process I prefer drying it
by the hot waste gases from the kiln, in a drying apparatus of the following
construction. Upon piers Z Fig. 1. 2. 3. of brick, concrete stone or other suitable
material, I build an arch supporting a drying apparatus in duplicate, at such a
height that the floor of its lower drying vaults V1 V Fig. 2. etc. is at a higher level
than the hereinafter described cold dried slip floor F Fig. 1 & 3. It is obvious
that the drying chamber (and other parts) can be supported at the necessary
height by natural elevations of the ground such as a hill or side of a quarry, when
such can be obtained; but I of course do not claim the exclusive use of such
natural elevations for that purpose. The hot waste gases from the kiln after
passing through and under the before mentioned pre-heating incline 1, Fig. 1. pass
into a pair of drying chambers by means of two vertical flues O' O' Fig. 1. A
pair of drying chambers is used so as to always have a passage for the hot waste
gases to the main flue when a chamber is being emptied, filled, or repaired. Both
vertical flues are provided at their upper part with dampers Y Y Fig. 2 etc. of.
any suitable kind, but preferably of cast iron plates which for convenience are
made in sections so as to be easily moveable. When it is desired to pass the hot
waste gases through a chamber I prefer to draw these damper plate sections Y Y
completely out and cover the aperture up by a plate Y Fig. 2 etc. having a pro-
jecting rim which is pressed into an under-cut groove Y Fig. 2 etc. packed with
asbestos. These damper plates can be pushed across each vertical flue so as to cut
off the supply of hot gases from the kiln when it is desired to draw and charge a
drying chamber. Each chamber is built of bricks containing fixed metal drying
plates arranged in tiers and made so short from front to back that it can be filled
and emptied from the exterior of the chamber hereinafter called the drying plates
compartments N' and N' Fig. 2 etc. When it is anticipated that the temperature
of the hot waste gases from the kiln will be high, I prefer to place each of the
drying plates compartments N and N over one or more drying vaults, but pre-
ferably two, built of brick, which vault or vaults is or are in communication with

page_text: one or both of the before mentioned vertical flnes O'O' Fig. 1. When using two
drying vaults one is placed over the other and the hot waste gases are conducted to
the back part of the lower one, then upwards through a draught holo U¹ Fig. 1.
to the upper vault V Fig. 1.-and afterwards through V' into the drying plates
compartment N' by means of a draught hole U Fig. 1. at the front. The drying
vaults may vary in length, V (dotted lines) Fig. 1. shows how they may be
lengthened, extra doors, staging etc. being provided, also the main flue U₁ Fig. 1.
raised so as to go over vaults V2 V4. The draught passages between the drying
plates and between the top plate and the roof, and also between the bottom plate
and the floor are not of the same dimensions but are so varied by projecting vertical
plates Us Fig. 1. secured to that end of each drying plate which is at the back of
the chamber so that the wet slip is dried upon them all at the same time. The
fixed drying plates arranged in tiers within the drying plates compartments N
and N' Fig. 2 etc. are preferably constructed of cast iron and may be of any con-
venient number. They are provided with ridges N Fig. 2 etc. cast or otherwise
formed upon their upper surface running from front to back so that said ridges will
offer no impediment to the withdrawal of the dried slurry. I have discovered that
it is not necessary for the ridges to be as high as the full depth of the slurry upon
the plates and they may be placed apart at any suitable distance so as to cause
cracks to be made which will form pieces of the required transverse sectional area,
thereby, permitting the heat to more readily penetrate the mass.
The drying vaults V₁ y y y Fig. 2 etc. have each only one layer of slurry
which is placed upon a floor made preferably of salt-glazed tiles having ridges
shaped and placed in a similar manner as the ridges upon the plates. The depth of
the slurry in the vaults and upon the roof of the upper vault is regulated by the
height of detachable bricks No No N' Fig. 1. or other forms of burnt fire clay, laid
in or luted by thick slurry. The depth of the slurry upon the plates is regulated
by the depth of detachable angle-irons N° Fig. 1. which fit into horizontal grooves
cast in or otherwise formed at the front edges of the plates, the depth of the slurry
at the back of the drying plates being regulated by vertical fixed plates N° Fig. 1.
cast or formed thereon. It is desirable that no part of the slurry either upon the
floors of the vaults or within the drying plates compartment shall be dried before
another part; I therefore cover the vaults with a thicker layer of slurry than the
plates, and moreover make the depth of the slurry upon the front end of the plates
greater by an inch or thereabouts by lowering that part. At a higher level than
the top of the drying chambers is an ordinary slurry reservoir and slurry main N¹º
Fig. 2 etc. provided with the usual slurry slides Nif Fig. 2 etc. or other valves, aud
with canvas pipes and caps for cach chamber. I prefer the handle of each slide to
be a double lever provided with ropes N" Figs. 1 & 3 carried over pullies to the
front of the chamber so that I can regulate the flow of the slurry without being
upon the chamber. I prefer filling each chamber by allowing the semi-fluid slurry
to fall from plate to plate and finally into the drying vaults. This can be done by
arranging them in the following manner. Although the plates may be of the same
size, all their front ends and their back ends are not in the same vertical plane, but
are placed in a zig-zag manner so that the slurry from a plate can overflow onto a
plate immediately beneath it, fill that plate until it overflows at the other end, and
in turn falls upon another plate immediately beneath, and so on until all the plates
are filled and also the floor of the drying plates compartment. From thence the slurry
falls into the upper drying vault, by way of the draught hole U, Fig. 1. filling it, and
finally overflowing into the lower vault by the draught hole UI at the back. At that
end of any plate which is not used as the overflow end, a vertical removeable
plate can be used to prevent overflowing at that part. To facilitate the filling and
levelling of the slurry a scraper of the usual kind is employed such as is commonly
used for such work. When all parts of the chamber are filled and the cap N
Fig. 1. replaced over the hole through which the slurry is admitted, the hereinafter
described chamber doors are shut. Then by opening the before-mentioned plate
dampers Y' or Y¹ at the front of the chamber and also by opening the hereinafter

page_text: to be described swing dampers Y or Y' at the back, the hot waste gases will dry
the slurry. When the slurry is dried, the dampers of that half part are all shut.
Its chamber doors are then opened, and the slurry is raked out, from off the plates.
and floors of the drying chamber by men using rakes or other tools (when standing
upon the floor F¹ Figs. 1. 3. 4 or upon the adjustable platforms N13 N14 N1 N16)
Fig. 1. on to a fire-proof floor Fs placed over the kiln called the cold dried slip
floor. This floor with its beams and roof is preferably supported by the piers ZZ
of the drying chamber and by a pair of pillars C and C Figs. 1. 3. 4. reaching
down to and supported by a protruding part C³ Fig. 1. of the kiln walls imme-
diately beneath the coking floor. In raking the dried slurry out of the chamber,
1 profer to let the contents of the vaults slide down short detachable inclined
shoots N Fig. 1 so as to lie near to the chamber and also prefer that the
contents of the drying plates shall slide down longer shoots N18 Fig. 1. so as to
lie further away from the chamber. as at M' Fig. 1. From this heap of dried
slurry the before-mentioned hopper H' is filled from time to time as it becomes
empty. The interior of each drying chamber may be lighted by any suitable
illuminant but preferably by coal-gas. I prefer lighting the drying plates
compartment in the following manner. Through a hole N Fig. 1. in the
roof fitted with a draught-tight cap I suspend a vertical detachable gas-tube.
This is provided with a sufficient number of gas burners at the requisite intervals
to illuminato the floor and every plate in the compartment. The upper part of the
tube has a union in order to couple the detachable tube to a cock, said cock
screwed to a gas supply pipe. By another branch supply pipe also furnished with
a cock the gas is conveyed to the two vaults. Two smaller pipes N2 Fig. 1. are
fitted to the said branch pipe and are also provided with unions and burners.
These smaller pipes are conveyed through holes in the said wall of the drying
chamber, said holes being provided with detachable plugs. The burners in the
vaults are preferably lighted simultaneously by ignited wax tapers fixed upon a two
armed long rod pushed through one of the vaults. The burners in the drying
plates compartment are preferably lighted (through a hole in the roof of the
chamber) by ignited wax tapers fixed upon a rod at such intervals that all the
burners of the compartment can be lighted simultaneously. The front parts of
the chambers are provided with different kinds of doors. The drying vaults
having hinged doors and each drying-plates-compartment having a suspended door
provided with wheels. The suspended door is constructed with an outer plate
preferably of corrugated galvanized sheet iron, and with an inner plate preferably
of sheet copper with a layer of slag wool interposed between them to reduce
radiation of heat. These two plates of each suspended door are rivetted to a
frame made of angle or channel iron, or any other rolled iron which will have
as a frame a projecting rim. that can be pressed into au under cut groove N
Fig. 2 etc. packed with asbestos. This under cut groove is formed in a cast iron
frame secured to the brick work at the entrance to the compartment, the groove
being turned outwards. The wheels of the suspended door are run upon the
web of and between the flanges of a channel iron rail N Fig. 2. 4 etc. spanning
the distance between two pairs of drying chambers, so that not only can the
door be wheeled away from the front of the chamber but can also be moved a
few inches transversely. Also a further amount of transverse motion can be given
by having long axles N to the wheels. In this way sufficient clearance will be
given between the chamber and the door.
The doors of the drying vaults below the drying plates are hinged to a frame
and are constructed as hereinbefore described, namely, with slag wool and with a
projecting rim pressing into an under cut groove packed with asbestos; but prefer-
ably having fireclay tiles upon their inner side. The dampers Y Y Fig. 1 and 4
which regulate the admission of heated gases from the kiln are similarly caused to
6t draught-tight, and are each provided with a shaft or spindle to which is
attached a long lever O Figs. 3 and 4 operated from the extorior of the drying

page_text: chamber. The damper is retained open by a tripping lever O³ Fig. 3 arranged to
hold the long lever before mentioned.
Two other levers are attached to the tripping lever 03 one carrying a counter-
weight O Fig. 3 and the other O' Fig. 3 placed so that the fall of a weight 0°
Fig. 3 (within its guide tube) upon it causes the said tripping lever O' to release
the damper lever O. A rope O'Fig. 3. attached to said damper lever 02 passes
over suitable pullies at the side of the drying chamber to the coking floor so
that the meu, stationed there and also those stationed at the drying chambers,
may regulate it. The weight O which is arranged to fall upon, and release the
tripping lever mechanism before mentioned, is retained by a cord 0 Fig. 3 with
a ring pulling upwards against a smooth pin, upon a spindle O Fig. 3 which passes
in an air tight manner through and into the drying chamber where a secoud crank
or lever O Fig. 1 is held, by, a short length of chain and a piece of lead or other
fusible wire Of Fig. 1. against the tension caused by the suspended weight 0*
Fig. 3. The fusible wire is imbedded in wet slip and thus cannot fuse and go
release the weight and close the damper, until said slip is dried. This device is
intended as a precautionary measure only to prevent over-heating and need not be
brought into requisition if ordinary attention be paid to the drying chambers.
The cord O Fig. 3 attached to the tripping lever O' and 0 is carried from
the drying chamber to the coking floor so that the damper can be opened by
attendants at each place. The products of combustion are in this apparatus
finally cooled by contact with the wet slip in the drying chambers. so as to be
practically useless in creating a draught by convection unless a chimney of great
height be employed. To obviate. this I employ an exhaust fan E' Fig. 2. 3. 4.
with a water cooled spindle E Fig. 2. 3. 4. and driven by a gas-engine E Fig. 2
and 4 or other suitable motor to create a partial vacuum in the main flue U
Figs. 1. 2. 3. 4. In order to still further cool the gases so that the vanes and
casing of the fan may not be injured I employ a cooling chamber U6 Fig. 3. 4.
having a roof of iron plates. I also roof the main flue with iron plates covered
with slurry, the combined area being sufficient for the purpose of such cooling.
To ensure efficient lubrication under these circumstances I form the fan spindle
with two shallow grooves cut into it, and water boxes E' E Figs. 2 and 4. made
to fit them and running nearly to the centre of said spindle E. Currents of cold
water are caused to play upon the spindle and are received by the water boxes
before mentioned, and may be carried away by an overflow pipe to the water
vessel of the gas-engine-or-to the wash mill. That part of the spindle in the water
box may also be provided with discs or rings in order to give more cooling surface.
If by reason of a break-down or stoppage the fan E is not in use, a steam-jet E
Fig. 3 and 4 may be used, which is ordinarily covered by a lid E' Fig. 3 etc.
(with a sand joint) when not required.
Also when the fan is not in use I cover the discharge outlet of said fan by a
lid E Fig. 2 and 3. having a sand joint. The outlets of the steam-jet E' and
also of the fan E' are each preferably covered and uncovered by similar appliances
⚫as shown.
To uncover an outlet, the lever is raised upwards (thereby raising
the lid clear of the sand joint) and hooked to a link hanging from the loose wheel,
the lid, its lever and wheels can then be moved away from the outlet. To close
the outlet again the foregoing operations are repeated but in reverse order.
I may in some cases employ a draught regulator or governor.shaped like a
small gas-holder E' Figs. 2 and 4. working within a tank of water or mercury,
balanced by weights E Fig. 2 and 4 which may be taken off or added for purposes
of adjustment. A double coned weight E" Figs. 2 and 4 attached to a screwed
spindle regulates the travel of the holder vessel E Fig. 2. 4 by adjusting the
distance between said cones E" Fig. 2. The interior of the holder vessel is con-
nected by a pipe E Fig. 4 to the main flue so that the partial vacuum therein
may cause the descent of the holder vessel under the weight of the atmosphere.
A suitable connection E" Fig. 2 is established between the regulator and the
11

page_text: motor driving the fan so that the speed thereof may be regulated according to the
predetermined partial vacuum in the main flue. In order to prevent injury to
the brickwork by an explosion within the gas flues when the gas is first lighted at
gas-exit ports G G G Fig. 1. in the kiln, I may before admitting the gas displace
the air within the gas-flues by admitting carbonic-acid gas through the cocks G¹² G",
Fig. 3. and when the carbonic-acid gas has in its turn been displaced by coal gas
adinitted through the cocks G G Fig. 3 from the outlet main G", I then ignite
the escaping coal gas at each set of ports G G G Fig. 1. by means of small gas-
jets having an independent air supply. This air supply to each igniter may come
from a fan or bellows, and conveyed through a tube.
This has also an inner gas tube provided with a burner, which burner is just
within the air tube and close to the end of the air tube. I may use a portable
apparatus for generating or storing the carbonic-acid gas. I prefer keeping the
coke charging doors, and also the hot slip charging doors draught-tight in the
same manner as the before-mentioned chamber doors, that is by a lip on the doors
pressing into asbestos packing placed within an under cut groove in a frame fixed
around the door opening.
Having now particularly described and ascertained' the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
:―
First. In apparatus for the manufacture of Portland cement, the construction
and use of a kiln in combination with various appliances for effecting the better
working thereof, substantially as herein described and shewn by the appended
drawings.
Second. In apparatus for the manufacture of Portland cement, the construction
and use of pre-heating platforms PP" and a pre-heating incliue I with draught
passages F F F F F as shewn, in combination with a kiln substantially as herein
described and shewn by the drawings.
Third. In apparatus for the manufacture of Portland cement, the construction
and use of a kiln with an arch W' and a dividing wall, in combination with a
retort or retorts R substantially as herein described and shewn by the appended
drawings.
Fourth. In apparatus for the manufacture of Portland cement the construction
and use of a hopper H, air tight door L, and trap T¹ with its mechanism in com-
bination with a kiln and its accessories as referred to in the preceding claims,
substantially as and for the purpose herein described and shewn by the appended
drawings.
Fifth. In apparatus for the manufacture of Portland cement the construction
and use of the scoop filler B substantially as and for the purposes herein described
with reference to the appended drawings.
Sixth. In apparatus for the manufacture of Portland cement the method of and
means for utilising the heat of the hot waste gases for drying purposes by a vault
or vaults in combination with plates arranged in irregular order and an auto-
matically closing damper substantially as herein described with reference to the
drawings.
Seventh. In apparatus for the manufacture of Portland cement the employment
of a fan E having a water-cooled spindle E' in combination with a kiln and its
accessories as referred to in the preceding claims, and as and for the purpose.
herein described with reference to the appended drawings.
Eighth. In apparatus for the manufacture of Portland cement, the construction
and use of the automatic draught regulator E E E" E" and E substantially as
herein described with reference to the appended drawings.
Ninth. In apparatus for the manufacture of Portland cement, the charging of a
kiln with hot coke substantially as herein described.
Tenth. In apparatus for the manufacture of Portland cement, the method of
C

page_text: making the doors and dampers draught-tight or practically air-tight substantially
as herein described:
Dated this 3rd day of April 1892.
FREDK. WALKER,
11, Furnival Street, Holborn, London, E.C., Agent for the Applicant.