IMPROVEMENTS IN THE MANUFACTURE OF CEMENT
Year: 1885

page_text: I FREDERICK RANSOME of Lower Norwood in the County of Surrey Civil
Engineer do hereby declare the nature of my invention for IMPROVEMENTS IN
THE MANUFACTURE OF CEMENT to be as follows:-
"
The ordinary way of burning cement material is to place it in blocks or lumps
together with fuel into a kiln-it has also been proposed to effect the burning of
the cement material by feeding it in a partially pulverized state into a rotating
chamber heated by the combustion within it of powdered coal and air.
When such means of burning the cement material has been adopted it has
always been necessary to grind the cement after burning to bring it to the requisite
degree of fineness.
According to my invention I reduce the cement material to the state of a fine
dry powder before passing it into a furnace to be burnt and for burning the
powder I employ a slowly revolving chamber heated by the combustion within it.
gas
obtained from coal coke petroleum or other hydrocarbon in a gas producer
any suitable construction.
of
of
The fine dry powder may either be introduced into the revolving chamber at the
end which leads to the chimney and pass from it at the other end at which the
stream of gas and air to be burnt are introduced-or may be introduced together
with or at the same end as the gas and air and pass from it at the chimney end.
The rotating chamber I set at an angle so that as it rotates the cement material
is caused to travel gradually from the end at which it is introduced to the outlet
end.
By introducing the cement material into the rotating chamber as a fine powder
the necessity for grinding the cement after burning is entirely obviated.
1007
CARPMAEL & Co.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Cement.
I, FREDERICK RANSOME of Lower Norwood in the County of Surrey Civil
Engineer 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 :--
The ordinary way of burning cement material is to place it in blocks or lumps
together with fuel into a kiln-it has also been proposed to effect the burning of
the cement material by feeding it in a partially pulverised state into a rotating
chamber heated by the combustion within it of powdered coal and air.
When such means of burning the cement material have been adopted it has
always been necessary to grind the cement after burning to bring it to the
requisite degree of fiueness.
According to my invention I reduce the cement material say as clay and chalk
to the state of a fine dry powder before passing it into a retort or furnace to be
burnt and for burning the powder I prefer to employ a slowly revolving chamber
or cylinder heated by the combustion within it of gas obtained from coal, coke,
petroleum, or other hydrocarbon in a gas producer of any suitable construction.
The fine dry powder may either be introduced into the revolving chamber at
the end which leads to the chimney and pass out from it at the other end at
which the stream of gas and air to be burnt are introduced, or may be introduced
together with or at the same end as the gas and air and pass out from it at the
chimney end. The rotating chamber I set at an angle so that as it rotates the
cement material is caused to travel gradually from the end at which it is introduced
to the outlet end.
By introducing the cement material into the rotating chamber as a fine powder
and by keeping it in continuous movement as it travels through this chamber the
necessity for grinding the cement after burning is entirely obviated.
Other forms of furnace into which the cement material can be introduced in the
form of a tine powder and be kept in continuous movement whilst it is in the
furnace might be employed I prefer however to employ a rotating cylinder heated
by the combustion of gas within it as above described.
Figure 1 of the drawings hereunto annexed is a longitudinal vertical section and
Figure 2 a plan in section of a furnace constructed in the manner I prefer for
carrying out my invention.
A is an inclined cylinder supported on rollers, so that, it may be revolved freely
like other revolving furnaces. B is a worm gearing into a ring of teeth sur-
rounding the exterior of the cylinder at its centre by which a slow revolving
motion can be imparted to' the cylinder. C is a pipe by which gas can be passed
into the lower end of the cylinder or furnace from a gas producer D-which may
be placed in any convenient position-E are rollers upon which the furnace
cylinder revolves-F is a pipe by which a blast of air or steam or both may be

page_text: introduced into the cylinder or furnace together with the gas-F is the nozzle
through which steam can be admitted.-G is a hopper through which the powdered
cement material can be introduced into the upper end of the cylinder or furnace-
H is the chimney outlet-I is a settling pit in this outlet in which any cement
material carried into this chimney outlet may settle and when removed therefrom
be again fed into the hopper G-K is a pit at the lower end of the revolving
furnace into which the burnt cement drops. It can be removed from this pit
through a side opening K as shewn in Figure 2. L is a valve for regulating the
admission of gas-M is a damper for regulating the draft to chimney.
I prefer to heat the revolving furnace by the combustion of gas introduced into
it in the manner above described but other means of heating the interior of the
revolving furnace might be adopted.
To manufacture Portland cement in the above described manner the materials of
which the cement is to be composed such as clay and chalk are first intimately
mixed together either in the dry or wet state. If in the wet state the mixed
materials or slurry" is dried, then pulverised and afterwards sifted to bring it to
the degree of fineness required in the sifted cement. Afterwards the finely
powdered material so obtained is fed from the hopper G into the rotating furnace
and as the furnace rotates it is kept constantly turning over and over by the
rotation of the furnace and is so exposed in a very uniform manner to the action
of the burning gases which are passing through the furnace so that every particle of
the cement material is subjected to the same heat and is uniformly burnt instead
of some parts being overburnt whilst others are underburnt as is the case in the
manufacture of cement in the usual manner.
Cements made with other materials than clay and chalk which require to he
burnt may similarly be reduced to a powder of the requisite fineness before burning
and he then burnt in a revolving furnace so that after burning they may be used
without grinding and sifting.
Figure shows a vertical longitudinal section and Figure 4 a plan in section of
a modified form of the gas heated cement furnace.
In these figures A is the rotating cylinder. B the worn for rotating it. C. a pipe
by which gas is introduced into a combustion chamber at the end of the cylinder A.
The products of combustion from this combustion chamber after being led through
the cylinder A in place of being allowed to pass from the opposite end of the
cylinder directly to the chimney are led downwards into a horizontal flue pipes or
other suitable channels D which lie hetween two air flues E and afterwards back
to the chimney H through other flnes pipes or other channels F which lie along the
outer sides of the flues E. In this way all air passing into the furnace through
the flues E gets highly heated before it enters the combustion chamber through the
descending flues E there to mingle and turn with the combustible gas introduced
into the combustion chamber through the pipe C.
The arrows shew the direction in which the heated products of combustion and
the air pass through the several flues or channels.
Amongst the advantages derived from manufacturing cement in the above
manner may be stated
1. The great saving of space occupied for works.
2. The comparatively insignificant amount of capital required for plant and the
small amount of wear and tear.
3. Great saving in labor, no skilled mechanics required.
4. Great saving in cost of fuel. The great waste of heat experienced in burning
the material in lumps being avoided.
5. Superiority of quality, the cement being burnt uniformly and not liable to be
over-burnt on the outside and under burnt in the inside of lumps as is the case in
formation of cement clinker by the present method.
6. No subsequent grinding required,
7. No delay in loading, cooling or drawing, but the operation may be continuous.

page_text: 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
1. The process of manufacturing Portland and other cement substantially as
herein before described consisting in first reducing the cement material to a dry
powder according to the degree of fineness required in the burnt cement, and then
burning such dry powder by keeping it in continuous movement whilst exposed to
the heated products of combustion of a gas or other furnace so that the cement
produced may be used without subsequent grinding.
2. The process of manufacturing Portland and other cement substantially as
bereinbefore described consisting in first reducing the cement material to a dry
powder according to the degree of fineness required in the burnt cement and then
burning such powder in a slowly revolving chamber heated by the combustion of
gas substantially as described.