Improvements in the Manufacture of Portland Cement and in Apparatus therefor.
Year: 1899

page_text: Date of Application, 4th Mar., 1899
Date of Application, 4th Mar., 1899
Complete Specification Left, 2nd Dec., 1899-Accepted, 27th Jan., 1900
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Portland Cement and in
Apparatus therefor.
I, LEEDHAM WHITE, of 2, Lime Street Square, in the City of London, Cement
Manufacturer, do hereby declare the nature of this invention to be as follows:-
The manufacture of Portland cement from the ground materials as usually
carried on in Great Britain may be divided into three stages.
1. The wet slurry is dried;
2. Is calcined; and
3. Is vitrified or clinkered.
According to this invention these steps are performed in three rotating fur-
naces preferably slightly inclined and placed one above the other so that the
material descends through them in turn by gravity.
The lower furnace in which the clinkering takes place is heated by flame enter-
ing at one end, the products of combustion escaping at the other end into a flue
passing along the middle or calcining furnace and from thence into the lower
end of the upper or drying furnace from the upper end of which the now cooled
products of combustion together with the steam pass to the chimney.
.
The material in the middle furnace is calcined by the heat of the flue so that
the resulting carbonic acid is practically pure and unmixed with the products of
combustion and nitrogen. This carbonic acid is drawn off and passed through
heated fuel being thus converted into carbonic oxide which is burnt to heat the
lower furnace.
In cases where dry material is employed the upper furnace is omitted.
Dated this 2nd day of Vasal 1000
Improvements in the Manufacture of Portland Cement and in
Apparatus therefor..
I, LEEDHAM WHITE, of 2, Lime Street Square, in the City of London, Cement
Manufacturer, 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 manufacture of Portland cement from the ground materials as usually
carried on in Great Britain may be divided into three stages.
1 The wet elurry is dried ·

page_text: 3. Is vitrified or clinkered.
According to this invention these steps are performed in three rotating fur-
naces preferably slightly inclined and placed one above the other so that the
material descends through them in turn by gravity.
The lower furnace in which the clinkering takes place is heated by flame enter-
ing at one end, the products of combustion escaping at the other end into a flue
passing along the middle of or surrounding a calcining furnace and from thence
into the lower end of the upper or drying furnace from the upper end of which
the now cooled products of combustion together with the steam pass to the
chimney.
The material in the middle furnace is calcined by the heat of the flue so that
the resulting carbonic acid is practically pure and unmixed with the products of
combustion and nitrogen. This carbonic acid is drawn off and passed through
heated fuel being thus converted into carbonic oxide which is burnt to heat the
lower furnace.
In cases where dry material is employed the upper furnace is omitted.
The drawing is an elevation partly in section of an apparatus constructed
according to this invention.
a b and c are three cylindrical furnaces and 6¹ is a flue surrounding and fixed
to the furnace b. The furnaces a and c and the flue 1 are mounted on rollers d
and have fixed to them toothed wheels e driven by pinions f in the ordinary way.
g is a hopper by which wet slurry is supplied to the furnace a and h is a hopper
leading the dried slurry into the furnace b. is a self closing valve at the
bottom of the hopper h. j is a hopper leading the calcined material from the
furnace into the furnace c and is a self closing valve in it. kk¹ are gas and
air pipes for producing a blast of flame at the entrance of the furnace c. I is a
fixed casing or flue into which the upper end of the furnace c and lower end of
the flue open so that the products of combustion pass from the one to the
other. m is a similar casing at the upper end of the flue b¹ and m¹ is a flue lead-
ing the products of combustion from it into the furnace a. n is a casing and
a chimney at the upper end of the furnace a. o is a pipe by which the carbonic
acid liberated in the furnace 6 is led away.
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 manufacture of cement in two rotating furnaces, the second heated
internally by products of combustion, the first heated by a flue carrying off the
products of combustion from the second, the cement making material being cal-
cined in the first furnace the carbonic acid so produced being drawn off free from
admixture with the products of combustion, whilst the calcined material is
transferred to the second furnace and there clinkered.
2. The combination with the subject matter of the First Claim, of another
furnace in which wet slurry is dried.
3. The process of and apparatus for the manufacture of Portland cement sub-
stantially as described and illustrated in the drawings.
Dated this 30th day of November 1899.