Improved Means applicable for use in the Manufacture of Cement.
Year: 1897

page_text: Date of Application, 5th Aug., 1897
Improved Means applicable for use in the Manufacture of Cement.
I, FRANKLIN DAVID CUMMER, President of the F. D. Cummer & Son Company,
of 616, The Arcade, Cleveland, State of Ohio, one of the United States of America,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to the manufacture of cement direct from liquid slurry,
and particularly to means for rapidly converting the slurry from the fluid to
the plastic state, so as to admit of its being dried far more rapidly than is
possible where the material is exposed in a fluid state (for the purpose of being
dried) and necessarily has to be confined in a vessel of some description.
A
In applying my invention to the manufacture of cement direct from liquid
slurry, I allow the slurry to flow to a pug-mill or similar mixing apparatus,
and I there add a certain proportion of the same material in a dried state.
comparatively small addition of dry material serves to convert the slurry from a
condition in which it will flow to a condition in which it will not flow, but, on
the contrary, will remain fairly stable if heaped upon a plate or pallet. I have
found that cement slurry containing 40 per cent. of moisture may be pumped,
or may be caused to flow; whereas after the addition of such a proportion of
dry material as will reduce the moisture present to 36 per cent., the slurry
assumes a plastic condition admitting of its being heaped upon plates or pallets.
The pallets are preferably made from sheet metal and have their edges slightly
turned upwards for stiffening purposes as also with a view to supporting the
plastic slurry whilst undergoing the drying process. The pallets having been
charged are placed on trucks which, when fully loaded, are run into drying
tunnels traversed by currents of hot air or furnace gases. If the rails be set at a
suitable inclination, the whole length of the trucks may be pushed forward as
each one enters, a truck load of dry material being simultaneously delivered
at the opposite end of the tunnel. The pallets are thereupon removed from the
truck and their contents discharged into the calcining furnace.
In order to provide dry material for mixing with the liquid slurry, about one
fifth of the dried, but uncalcined, slurry is returned to the pug-mill, and, after
being ground, is ready for admixture with the wet slurry in properly regulated
proportions.
According to the practice hitherto commonly in use, cement slurry is allowed
to stand for long periods in subsiding tanks, and even then is usually too liquid
to admit of being handled and dried in the manner above described. By my
improved method of treatment, the manufacture of cement direct from liquid
slurry becomes practically a continuous process, the saving of time and labour
being very considerable, whilst far less space is occupied.
1907

page_text: Improved Means applicable for use in the Manufacture or Cement.
I, ERNEST CARTWRIGHT STEVENSON, of 3, Fenchurch Street, in the City of
London, Solicitor, Administrator of the late Franklin David Cummer, President
of The F. D. Cummer & Son Company, of 616, The Arcade, Cleveland, State of
Ohio, one of the United States of America, 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:
-
This invention relates to the manufacture of cement direct from liquid slurry,
and particularly to means for rapidly converting the slurry from the fluid to
the plastic state, so as to admit of its being dried far more rapidly than is
possible where the material is exposed in a fluid state (for the purpose of being
dried) and necessarily has to be confined in a vessel of some description.
In applying this invention to the manufacture of cement direct from liquid
slurry, the slurry is allowed to flow to a pug-mill or rinsing apparatus, and to
that there is added a certain proportion of the same material in a dried state. A
comparatively small addition of dry material serves to convert the slurry from
a condition in which it will flow to a condition in which it will not flow, but,
on the contrary, will remain fairly stable if heaped upon a plate or pallet. It
has been found that cement slurry containing 40 per cent. of moisture may be
pumped, or may be caused to flow; whereas, after the addition of such a propor-
tion of dry material as will reduce the moisture present to 36 per cent., the
slurry assumes a plastic condition admitting of its being heaped upon plates or
pallets.
The pallets are preferably made from sheet metal and have their edges slightly
turned upwards for stiffening purposes as also with a view to supporting the
plastic slurry whilst undergoing the drying process. The pallets having been
charged are placed on trucks, which, when fully loaded, are run into drying
tunnels traversed by currents of hot air or furnace gases. If the rails be set at a
suitable inclination, the whole length of the trucks may be pushed forward as
each one enters, a truck load of dry material being simultaneously delivered
at the opposite end of the tunnel. The pallets are thereupon removed from the
truck and their contents discharged into the calcining furnace.
In order to provide the dry material for mixing with the liquid slurry, about one
fifth of the dried, but uncalcined, slurry is returned to the pug-mill, and, after
being ground, is ready for admixture with the wet slurry in properly regulated
proportions.
According to the practice hitherto commonly in use, cement slurry is allowed
to stand for long periods in subsiding tanks, and even then is usually too liquid
to admit of being handled and dried in the manner above described. By the
improved method of treatment, the manufacture of cement direct from liquid
slurry becomes practically a continuous process, the saving of time and labor
being very considerable, whilst far less space is occupied.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
j
1. In the manufacture of cement from liquid slurry, the method consisting,
first, of mixing with liquid slurry a certain proportion of the same material in
a dried and pulverized state so as to bring the material to a plastic condition,

page_text: and then subjecting the material to the action of currents of hot air, or furnace
gases, until the contained moisture is driven off, substantially as described.
2. The method of manufacturing cement from cement slurry, which consists
in incorporating with the slurry a sufficient quantity of the same material in a
dried and powdered state to make the mixture plastic; then drying the mixture
by exposure to hot air or furnace gases, and finally calcining the material, sub-
stantially as described.