Improvements in the Manufacture of Finely Pulverised Substances for Use in the Production of Portland Cement, Pigments, and the like.
Year: 1893

page_text: Date of Application, 9th Nov., 1893
Complete Specification Left, 7th Aug., 1894-Accepted, 22nd Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Finely Pulverised Substances
for Use in the Production of Portland Cement, Pigments, and
the like.
I, ALEXANDER PATRICK, of 82 Gordon Street, Glasgow, in the County of
Lanark, North Britain, Merchant, do hereby declare the nature of this invention
to be as follows, that is to say :-
My said invention has for its object the manufacture of Portland cement of
superior and uniform quality, in an improved manner, an important part of the
invention consisting in the preparation and separation of the ingredients in a state
of fine pulverisation, and free from gritty and insufficiently ground particles; and
the invention is advantageously applicable in the manufacture of dry powders,
used as pigments or for various other purposes.
In carrying out my invention according to a modification suitable for the
manufacture of Portland cement, the ingredients are passed through a stone
breaker, and through a pan mill the latter working without water.
From the pan
mill the roughly ground materials are elevated or conveyed to one or more pairs of
mill stones by which they are reduced to the desired fineness.
The finely-ground materials are next, by means of a rotating or other suitable
feeder, introduced into a wind duct supplied with compressed air by a Roots blower
or other suitable apparatus, and are by the air carried to a screen or sieve of fine
wire gauze which covers an opening into a large hopper or chamber. The screen
is by preference in an inclined position and the materials are driven against its
underside. The air current carries the fine particles of the materials through the
screen; and any particles not sufficiently fine are withdrawn by a rotating or other
suitable feeder and passed back to be ground over again. The chamber or set of
chambers into which the finely pulverised material is blown, is made of sufficient
size to allow of the material being deposited from the air; to prevent loss of
material, however, the same air is made to circulate repeatedly through the
apparatus.
Instead of the blowing apparatus being arranged to blow the air towards the
screen it may be arranged to act by exhausting it after passing through the screen;
or pressure on one side may be combined with exhaust action on the other.
Dated this Eighth day of November 1893.
EDMUND HUNT,
Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Finely Pulverised Substances
for Use in the Production of Portland Cement, Pigments, and
the like.
I, ALEXANDER PATRICK, formerly of 82 Gordon Street, but now of
16 Bothwell Street, in the County of the City of Glasgow North Britain,
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:-
My said invention has for its object the manufacture of Portland cement of
superior and uniform quality, in an improved manner, an important part of the
invention consisting in the preparation and separation of the ingredients in a state
of fine pulverisation and free from gritty and insufficiently ground particles; and

page_text: the invention is advantageously applicable in the manufacture of dry powders used
as pigments or for various other purposes.
And in order that my said invention and the manner of performing the same
may be properly understood I hereunto append a sheet of explanatory drawings
showing by way of example a modification of my improved apparatus.
Figure 1. on the accompanying sheet of drawings is a sectional side elevation of.
the apparatus, Figure 2. being a face view of a part to be hereinafter referred to.
In carrying out my invention according to a modification suitable for the
manufacture of Portland cement, the ingredients are passed through a stone
breaker A. and afterwards by a duct B. to and through a pan mill C. the latter
working without water. From the pan mill C. the roughly grad materials are
by an elevator D. conveyed to a duct E. down which they descent so the hopper of
a pair of mill stones F. by which they are reduced to the disired fineness. There
may be more than one pair of mill stones if thought desirable.
The finely-ground materials next fall down a duct G. and are then raised by an
elevator H. and duct J. into a hopper K. out of which they are fed in a regular
manner by a rotating (or other suitable) feeder L. and introduced into a wind
duct M. supplied with compressed air by a Roots blower N. or other suitable
apparatus. The materials are by the air carried into a chamber P. the air duct M.
being made broad so as to suit the shape of the bottom of the chamber. One
side of the chamber P. is in the form of a screen or sieve Q. of fine wire gauze
which covers
an opening into a large hopper or chamber R. The screen Q. is in
an inclined position, and the materials are driven against its underside, but when it
is desired to give the screen a larger area this may be done by extending it inwards
as shown by the dotted lines S.
A deflector T. is fitted on the bottom of the chamber P. so as to give the air
current an upward tendency. The air current carries the fine particles of the
materials through the screen Q. and any particles not sufficiently fine fall down and
are withdrawn by a rotating (or other suitable) feeder U. and pass back through a
duct V. to the mill stones F. to be ground over again.
The chamber R. into which the finely pulverised material is blown, is made of
sufficient size to allow of the material being deposited from the air; to prevent
loss of material however the same air is made to circulate repeatedly through the
apparatus, the air being withdrawn from a chamber W. separated by a screen X.
from the chamber R. and passing through a pipe Y. to the Roots blower N. The
deposited materials are withdrawn from the chamber R. by a rotating feeder Z.
Instead of the blowing apparatus being arranged to blow the air towards the
screen Q. it may be arranged to act by exhausting it after passing through the
screen; or pressure on one side may be combined with exhaust action on
the other.
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. In the manufacture of finely pulverised substances for use in the production
of Portland cement, pigments, and the like, the combination and arrangement of
parts constituting my improved apparatus substantially as hereinhefore described
and shown in the accompanying drawings.
2. In the manufacture of finely pulverised substances for use in the production
of Portland cement, pigments, and the like, the passing of the finely-ground
materials by an air current to and through a screen or sieve and into a depositing
chamber substantially as herein before described.
Dated this Fourth day of August 1894.
EDMUND HUNT,
Applicant's Agent.