Improvements in Cement, in “Cooling or Maturing the same, and in Apparatus therefor.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
,,
Improvements in Cement, in “Cooling or Maturing the same, and
in Apparatus therefor.
I ALEXANDER MCARA of 65 Morrison Street, Glasgow, in the County of Lanark,
Lime and Cement Merchant, do hereby declare the nature of this invention to be as
follows:-
:-
It is well known to users of Portland and other like cements that the material as
delivered from the manufacturers is in many cases unfit for immediate use and
requires to be submitted to the action of the atmosphere for a longer or shorter
time such submission having the effect of maturing or what is technically known
as "cooling" the cement.
This invention has partly for its object to hasten this "cooling" or maturing
process by passing the cement through apparatus especially designed for that object
and partly to produce an improved cement by the admixture with the ordinary
material of a proportion of carbonate of lime either whilst the cement is passing
through the cooling machine or before or after such passage.
The cooling or maturing apparatus consists of a cylinder or trunk within which
is arranged a series of shelves each shelf having in it a series of holes, slots
or openings and being inclined downwards from the circumference of the cylinder
towards the centre. The shelves immediately above or below each other project
alternately from opposite sides of the cylinder towards the centre, and through the
centre of the cylinder there passes a pipe which is perforated throughout or partially
throughout its length one end of the pipe being connected to a fan or other apparatus
for producing a blast or current of air.
The cement to be treated is filled in at the upper end of the cylinder and
falling down from shelf to shelf it is acted upon by the air current issuing from
and rendered fit for
the perforated pipe whereby the cement is "air slaked"
immediate use without the necessity of storing and frequently turning over as usually
pertains where large quantities of the material are to be used.

page_text: Under a modification the shelves may be connected to the perforated pipe after
the manner of an Archimedian screw in which case the pipe is or may be rotated
so as to deliver the treated cement at the opposite end of the cylinder or trunk
from that at which it is fed in. In treating the cement during hot weather there
may be injected into the air current a jet of water or steam.
<
The cement "cooled "matured or air slaked" in this way may during or before
or after treatment have added to it a proportion of carbonate of lime the addition of
which improves its setting qualities. Although I do not confine myself to that
proportion I have found ten per cent. of carbonate of lime a suitable proportion to
employ.
D
AT
21 1
CAL 1000

page_text: COMPLETE SPECIFICATION.
Improvements in Cement, in "Cooling" or Maturing the same, and
in Apparatus therefor.
I, ALEXANDER MCARA of 65 Morrison Street, Glasgow, in the County of Lanark,
Lime and Cement Merchant, 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 :-
It is well known to users of Portland and other like cements that the material as
delivered from the manufacturers is in many cases unfit for immediate use and
requires to be submitted to the action of the atmosphere for a longer or shorter time
such submission having the effect of maturing or what is technically known as
airslaking" and "cooling" the cement.
"
The invention has partly for its object to hasten this airslaking and cooling or
maturing process by passing the cement through apparatus especially designed for
that object and partly to produce an improved cement by the admixture with the
ordinary material of a proportion of carbonate of lime either whilst the cement is
passing through the cooling machine or before or after such passage the addition of
the lime having the effect of delaying the settling, and of increasing the ultimate
strength.
The airslaking and cooling or maturing apparatus consists as illustrated in vertical
section at figure 1 and in plan at figure on the accompanying drawings of a cylinder
or trunk A within which are placed shelves B. The shelves are inclined downwards
from the sides of the trunk or cylinder A towards the centre and they are so arranged
in series that the shelf above and secured to one side of the trunk projects partly
across the shelf immediately below and secured at right angles to it to another side of
the trunk each alternate shelf having a slot or slots C in it. Through the centre of
the trunk or cylinder A there passes. a pipe D which is perforated throughout or
partially throughout its length and connected by a branch E to a fan or other
apparatus for producing a blast or current of air.
The cement to be treated is filled in at the upper end of the trunk or cylinder A
and falling down from shelf to shelf it is acted upon by the air currents issuing from
the perforated pipe D whereby the cement is "air slaked" and rendered fit for use in
a much shorter time than by the ordinary method while the "air slaking" is much
more thoroughly effected and at less cost, the necessity of storing and frequently
turning over as usually pertains where large quantities of the material are to be
treated being obviated.
Under a modification the shelves may be connected to the perforated pipe after the
manner of an Archimedian screw in which case the pipe is or may be rotated so as to
deliver the treated cement at the opposite end of the cylinder or trunk from that at
which it is fed in. Under either arrangement in treating Cement during hot weather
there may be injected into the air current a jet of water or steam.

page_text: The cement "cooled," matured, or "air slaked" in this way may during or before
or after treatment have added to it a proportion of carbonate of lime the addition of
which improves its setting qualities. Although I do not confine myself to that
proportion I have found ten per cent. of carbonate of lime a suitable proportion to
employ.
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 :-
:-
1. The improved process of airslaking and cooling or maturing cement sub-
stantially as herein before described.
2. The improved apparatus herein before described and in part shewn on the
annexed drawings for cooling or maturing cement.
3. The improved cement consisting of ordinary Portland or like cement with the
addition of a proportion of carbonate of lime thereto.
Dated this Nineteenth day of January 1889
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.