Improvements in or relating to Apparatus for Slaking Lime or similar Material.
Year: 1899

page_text: Date of Application, 23rd Dec.,
4000
Complete Specification Left, 17th Aug., 1900-Accepted, 27th Oct., 1900
Complete Specification Left, 17th Aug., 1900-Accepted, 27th Oct., 1900
PROVISIONAL SPECIFICATION.
Improvements in or relating to Apparatus for Slaking Lime or
similar Material.
I, BENJAMIN WILLCOX, of 47, Lincoln's Inn Fields, in the County of London,
Patent Agent, do hereby declare the nature of this invention (which has been
communicated to me from abroad by La Société J. et A. Pavin de Lafarge, of
Viviers, Ardeche, in the Republic of France) to be as follows:
This invention relates to apparatus adapted to satisfactorily effect the slaking
of hydraulic substances, and more especially those kinds of lime (chaux limites,
chaux surcuites) which are obtained from limestone and which have been either
too clayey or overheated, to produce lime of a good quality and which, though
easy to slake, are yet not sufficiently clayey to produce good cement.
The quick lime in lumps ("en crotte") or cement, is charged into a hopper and
moistened with just sufficient water to slake it.
It is then introduced into a sheet metal cylinder or receiver which receives
rotary motion from any suitable driving gear through the medium of a pinion
engaging with a toothed rim on the cylinder or receiver. The interior of the
cylinder or receiver is fitted with multilated helices arranged to continuously feed
the material through the cylinder or receiver. The angle or pitch of the helics
is such as to cause the material being treated, to remain within the cylinder or
receiver for a period which is found best suited to the nature of the material.
The cylinder or receiver is fitted with ribs or projections which, during the
rotation of the said cylinder or receiver raise the material and then allow it to
drop so as to thoroughly agitate the said material.
The before mentioned cylinder or receiver is surrounded by a second sheet
metal cylinder forming a jacket connected with the inner cylinder or receiver
by means of tie rods or distance pieces.
The space between the two cylinders is filled with steam at say about 1 kilo-
gramme pressure so that the temperature within the inner cylinder or receiver
may not descend below 100° Centrigrade.
The steam, previously expanded, is admitted through pipes provided with a
safety valve and after having passed through the space between the two cylinders
the steam together with the condensation water is conducted into a vessel also
fitted with a valve and with automatic exhausting apparatus.
The apparatus is provided with a number of projecting rings or flanges which
bear upon rollers carried in bearings supported upon masonry or other suitable
framework. The inner cylinder or receiver is provided at the discharging end
with diametrically opposite blades terminating in a cone, which arrangement
prevents any matter from being discharged at the axis of rotation; during the
rotation of the apparatus, these blades cause a certain amount of the material
to emerge through an orifice provided in the discharging end of the inner cylinder
or receiver. By varying the dimensions of the said blades the time during which
the material shall be allowed to remain within the apparatus may be varied as
required

page_text: The material is charged into the hopper wherein it is moistened with sufficient
water to ensure satisfactory slaking, thence it is delivered into one end of the
inner cylinder or receiver where it is finally slaked and at the opposite end of
which it is discharged.
Throughout the process the temperature is prevented from falling below 100°
Centrigrade by the steam passing through the jacket.
As it is necessary to maintain the material at a temperature of 100° Centigrade
any mode of reheating may if desired be employed to attain that end, for example
such a re-heating arrangement may consist of straight steam-circulating pipes,
arranged longitudinally within the inner cylinder or receiver. These pipes, are
not parallel to each other or to the generatrices of the cylinder, and they are con-
nected in pairs at those ends which are nearest to each other, by means of short
pipes, so that altogether they constitute a species of coil. This arrangement of
pipes is suitably secured or mounted in the cylinder and supported by metal rings
which prevent them from becoming displaced.
The steam is conducted into the coil through one compartment of a pipe divided
into two such compartments by a diametrical partition. Thence it is conducted
backward and forward in the cylinder through the coil finally emerging together
with the water of condensation, through the second compartment of the before
mentioned divided pipe. The tubes of the heater may be arranged helically, or
in any other manner adapted to ensure a satisfactory circulation of steam.
avoid condensation of steam by contact with the metal wall of the apparatus
such wall may have a casing of non-heat-conducting material.
Το
The apparatus above described enables the following results to be attained.
1. The swelling of ground cement may be stopped in a few hours, a result which
hitherto has sometimes necessitated the placing of the cement in an ensilage for
a protracted period, whereby the cement need not be so finely ground, or the raw
materials be so intimately mixed as has been previously necessary, it also leaves
a greater margin in regard to the proportions of the ingredients of the mixture,
since the presence of a small excess of lime cannot be harmful.
2. Lime obtained from too clayey or over-burnt limestone (chaux limites, chaux
surcuites) may, by the before mentioned apparatus, he slaked and first class lime
obtained, while some of the material which has resisted slaking constitutes a
cement equal to the best cements known.
3. The two kinds of lime above mentioned may be slaked after trituration,
whereby products containing an exceptionally high proportion of lime, highly
resisting and absolutely safe, will be obtained.
4. Hydraulic limes may be slaked, and their quality improved, with but a small
amount of water.
5. Hydraulic limes may be slaked after trituration, whereby a novel hydraulic
preparation of excellent quality will be rendered available for use.
In order to complete the slaking it is often useful to leave the material for
from 24 to 48 hours after it has come out of the slaking cylinder, either in vertical
pits or in horizontal cylinders, in which a temperature of 100° Centigrade is main-
tained. For this purpose walls of non-conducting material covered with cork
or the like are provided, and these may be further protected say by a coating of a
suitable preparation, the material being discharged at the bottom or at one end,
by means of an endless screw, or other suitable device, in quantity equal to that
admitted at the other end. If necessary, apparatus adapted to retreat the material
when it is about midway of its journey through the slaking chamber may be
provided and thus any heat that that the material may have lost may be restored
to it, so as to maintain the temperature at 100° Centigrade.
Such an apparatus may for example comprise a double-cased or jacketed cylinder
or a cylinder fitted with re-heating pipes or tubes, as is the slaking cylinder pre-
viously described, and a cylinder made heat-retaining, say, by a cork ring or
flange wherein the stirring or agitation of the material is continued.
A further double-cased or heating-tube cylinder similar to that previously

page_text: described may be used wherein the material can be again raised to 100° Centigrade
should it have become cooled. The slaking process may be completed in a further
slaking cylinder similar to that previously described.
Dated this 23rd day of December 1899.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in or relating to Apparatus for Slaking Lime or
similar Material.
I, BENJAMIN WILLCOX, of 47, Lincoln's Inn Fields, in the County of London,
Chartered Patent Agent, do hereby declare the nature of this invention, (which
has been communicated to me from abroad by La Société J. et A. Pavin de
Lafarge, of Viviers, Ardeche, in the Republic of France) 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 apparatus adapted to satisfactorily effect the slaking
of hydraulic substances, and more especially those kinds of lime (chaux limites,
chaux surcuites) which are obtained from limestone and which have been either
too clayey or overheated, to produce lime of a good quality, and which, though
easy to slake, are yet not sufficiently clayey to produce good cement.
The invention will be clearly understood from the following description with
reference to the accompanying drawings in which
Fig. 1 is a longitudinal section of the slaking apparatus;
Fig. 2 is a cross section on line A-B Fig. 1;
Fig. 3 is a diagram of a battery of connected apparatus in section;
Fig. 4 is a longitudinal section of one of the apparatus comprising in its interior
means for the circulation of steam; and
Fig. 5 is a cross section on line C-D) Fig. 4.
The quicklime in lumps ("en crotte"), or cement, is fed into a hopper a, and
moistened with just sufficient water to slake it the said material passing from the
hopper into a sheet metal cylinder or receiver to which rotary motion is imparted
from any suitable driving gear through the medium of a pinion e engaging with
a toothed rimd on the cylinder or receiver. The interior of the cylinder or re-
ceiver is fitted with mutilated helices e arranged to continuously feed the material
through the cylinder or receiver. The angle or pitch of the helices is such as to
cause the material being treated, to remain within the cylinder or receiver for a
period which is found best suited to the nature of the material.
The cylinder or receiver is fitted with ribs or projections f which, during the
rotation of the said cylinder or receiver. raise the material and then allow it to
drop so as to thoroughly agitate the said material.
i
The cylinder or receiver b is surrounded by a second sheet metal cylinder forming
a jacket connected with the inner cylinder or receiver by means of tie-rods or
distance pieces h. The space between the two cylinders is filled with steam at
say say about 1 kilogramme pressure so that the temperature within the inner
cylinder or receiver may not descend below 100° Centigrade.
The steam, previously expanded, is admitted to the space i through pipes ; pro-
vided with a safety valve, not shown in the drawings, and after having passed
through the space i, the steam, together with the condensation water escapes
through pipes k, and is conducted into a vessel also fitted with a valve and with
automatic exhausting apparatus.
The apparatus is provided with projecting rings or flanges m which bear upon

page_text: rollers n carried in bearings o supported upon masonry or suitable frame work.
The inner cylinder or receiver is provided at the discharging end with radial
blades terminating in a cone q which arrangement prevents any matter from
passing through the hollow axis of the cylinder 6 during the rotation thereof the
said blades causing a certain amount of the material to pass from the cylinder
along the cone y and through an orifice r provided in the discharging end of the
said cylinder. By varying the dimensions, of the said blades the time during
which the material shall be allowed to remain within the apparatus may be
varied as required.
The material to be slaked is charged into the hopper a wherein it is moistened
with sufficient water to ensure satisfactory slaking. Thence it passes into one
end of the inner cylinder or receiver b where it is finally slaked and at the opposite
end of which it is discharged. Throughout the process the temperature is pre-
vented from falling below 100° Centigrade by the steam admitted to and passing
through the space i.
As it is necessary to maintain the material at a temperature of 100° Centigrade
any mode of reheating may be employed to attain that end.
Figs. 4 and 5 illustrate a re-heating arrangement consisting of straight steam-
circulating pipes 1 arranged longitudinally within the inner cylinder or receiver b.
These pipes 1 are not arranged parallel to each other nor to the generatrices of
the cylinder; they are connected together in pairs at those ends which are nearest
to each other, by means of short pipes 2, so that altogether they constitute a
species of coil. This arrangement of pipes is suitably secured in position in the
cylinder and are supported by metal rings 7 which prevent them from becoming
displaced.
The steam is admitted into the coil, through one compartment af a pipe 3 divided
longitudinally into two compartments by a diametrical partition 4. The steam
is conducted by a bent tube 5 to one end of the coil and after traversing in a
circuitous course through the said coil escapes together with water of condensation
through the pipe 6 and through the second compartment of the longitudinally
divided pipe 3. The tubes 1 may if desired be arranged helically or in any other
suitable manner to ensure a satisfactory circulation of the steam. To avoid con-
densation of steam by contact with the metal wall of the apparatus, such wall
may have a casing of non-heat conducting material.
The apparatus described enables the following result to be attained.
1. The swelling of ground cement may be stopped in a few hours, a result
which hitherto has sometimes necessitated the placing of the cement in an
ensilage for a protracted period, whereby the cement need not be so finely ground,
or the raw materials be so intimately mixed as has been previously necessary; it
also admits of a greater margin in regard to the proportions of the ingredients
of the mixture, since the presence of a small excess of lime cannot be harmful.
2. Lime obtained from too clavey or over-burnt limestone (chaux limites, chaux
curcuites) may, by the use of the improved apparatus, be slaked and first class
lime obtained, while some of the material which has resisted slaking constitutes
a cement equal to best cements known.
3. The two kinds of lime above mentioned may be slaked after trituration,
whereby products containing an exceptionally high proportion of lime, highly
resisting and absolutely safe. will be obtained."
4. Hydraulic lime may be slaked, and the quality thereof improved, with
but a small amount of water.
5. Hydraulic lime may be slaked after trituration, whereby a novel hydraulic
preparation of excellent quality will be rendered available for use.
In order to complete the slaking it is often advantageous to leave the material
for from 24 to 48 hours after it has come out of the slaking cylinder, in a pit or
chamber in which a temperature of 100° Centigrade is maintained.
The wall of the pit or chamber may be covered with non-conducting material
such as cork or the like and may be further protected say by a coating of any

page_text: suitable preparation. The material can be discharged from the chamber, through
an outlet at the bottom or at one end, by means of a screw or other suitable device
and in quantity equal to that being admitted to the chamber. If desired, apparatus
adapted to reheat the material when it has been traversed to about one half the
distance through the slaking chamber may be provided and thus any heat that the
material may have lost may be restored to it, so as to maintain the temperature
at 100° Centigrade.
Fig. 3 is a diagram illustrating an arrangement for this purpose in which s
represents a double-cased or jacketed cylinder; which may be provided with
reheating pipes or tubes, as in the slaking cylinder herein before described. The
material passes from the cylinder s into a cylinder or chamber t made heat-retain-
ing by a cork ring or flange in which chamber the stirring or agitation of the
material is continued without losing any of the heat the material had stored up
in the cylinder s. The material is conducted from the chamber t into a double-
cased heating cylinder u, similar to the cylinder s, wherein the material can be
raised to the temperature of 100° Centigrade should it have become cooled. The
material is next conducted into a chamber similar to the chamber t in which
chamber va further shaking or agitation of the material may be effected to com-
plete the process.
Having now particularly described and ascertained the nature of this in-
vention and in what manner the same is to be performed I declare that what I
claim is:-
:-
1. Apparatus for slaking hydraulic substances lime and the like and for im-
proving the quality of ground cements the said apparatus comprising a chamber
into which the substance to be treated is fed, means for rotating the chamber, and
means for maintaining the material while under treatment in the chamber at a
temperature of about 100° Centigrade substantially as herein before described.
2. Apparatus for slaking lime, hydraulic substances and the like, and for im-
proving the quality of ground cements, the said apparatus comprising a cylinder
into one end of which the material to be treated is fed, mutilated helical blades
in the cylinder to agitate and propel the material along the interior of the
cylinder an outer casing surrounding the cylinder so arranged as to provide an
annular space round the said cylinder, means for admitting steam or other heating
medium to the space between the cylinder and the outer casing and means for
imparting rotation to the cylinder, substantially as and for the purpose herein-
before described.
3. Apparatus for slaking lime, hydraulic substances and the like, and for im-
proving the quality of ground cement the said apparatus comprising a cylinder
into which the material is fed, pipes constituting a coil arranged within the
cylinder and means for circulating steam through the pipes or coil so as to main-
tain the material in the cylinder at the desired temperature substantially as and
for the purpose herein before described.
4. The combination with either of the apparatus constituting the subject matter
of claims one and two of an additional cylinder or chamber into which the material
from the said apparatus is conducted the said additional cylinder or chamber
being provided with heat retaining walls, and in which the material is enclosed
so long as is necessary to effect the complete process of slaking substantially as
herein before described.
5. The combinations and arrangements of parts constituting apparatus for
slaking lime, hydraulic substances and the like, and for improving the quality
of ground cement, substantially as hereinbefore described and illustrated by the
accompanying drawings.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.