An Improved Method of and Apparatus for Purifying Grain, Cereals, Wheat, Semolina, Middlings, Dunst, and the like.
Year: 1895

page_text: Date of Application, 8th Mar., 1895
Complete Specification Left, 16th Aug., 1895-Accepted, 7th Mar., 1896
PROVISIONAL SPECIFICATION.
An Improved Method of and Apparatus for Purifying Grain,
Cereals, Wheat, Semolina, Middlings, Dunst, and the like.
I, JAMES HIGGINBOTTOM of 32, Seel Street, Liverpool in the County of
Lancaster, Milling Engineer do hereby declare the nature of this invention to be
as follows:-
My invention is for a new method of purifying grain, cereals, wheat, semolina,
middlings, dunst and the like in sieve purifying machines in which a gauze sieve
surface is used having currents of air passing in an upward direction through the
same. In practice such sieve machines are arranged with a sieve gauze surface
having meshes larger than the bulk of the material which is passing to the machine
to he treated, in other words, the gauze covering on the sieve is arranged with a
mesh sufficiently large that the bulk of the feed material may pass through such
mesh into a chamber or receptacle below the sieve. The air currents are applied
with such force or intensity that the material as it is in the act of passing through
the hole of the mesh is met with an uprising current of air which is passing in an
opposite direction to the falling particles, and in such a manner that at the instant
of the passage of a particle, the speed of the uprising air current is intensified in
passing through the hole in proportion as the area of the hole is obstructed by the
downward passing particle. Thus, the current of air in the act of passing through
the hole between the threads of the mesh and the sides of the particle itself is
increased in velocity, and, as is well known in these machines, the air current can
be set so that the velocity of the air current at the particular moment described
shall be just such as will allow a particle of a heavier specific gravity to fall
through the hole into the chamber below, but too powerful to permit a similar size
of particle, of a less specific gravity passing through the hole. By such method of
purification a separation is effected betwixt the particles, such separation being
made according to the velocity of the air currents and the differences between the
specific gravities of the particles. In this method of purification, the sizes of the
mesh and the velocity of the wind current used are varied to suit the size and
nature of the particles, but in all cases, the purification or separation is done by an
uprising current of air passing through a hole and the purified particles of heavier
specific gravity passing downwards through the same hole, whilst at the same
time the particles of lighter specific gravity are prevented from falling through the
hole.
Now my invention is to obtain a method of purification or separation by specific
gravity in an entirely different manner, and I accomplish the saine as follows
:-
I make the meshes in the gauze covering of the sieve. smaller than the material
to be purified, in other words, the material to be purified cannot pass through the
meshes of the gauze covering, and I cause the air current to rise up through these
smaller meshes with a velocity sufficient to lift the particles of lighter specific
gravity out of the particles of heavier specific gravity onto a collecting tray of
nozzles or channels or other surfaces, placed above or contiguous to the material
moving over the sieve. I also make the sieve of a sufficient length from head to
tail thereof, so that the particles to be lifted have a length to travel under the
action of the uprising air current which is passed through the sieve, such as is
found to be sufficient to accomplish the desired degree of separation. In other

page_text: words if a particle entering the sieve arrives at one of these smaller holes and if
the wind rising through that particular hole fails to lift out the desired particle,
such particle must pass on to the next succeeding hole upon the sieve where it is
again met with a similar uprising current, so that if the particle to be extracted
does not become removed at the first or second or third hole over which it is
passing, its removal may be accomplished at some other point lower down the
sieve, and my new method enables me to bring the particle successively under the
action of the air currents until it becomes removed of a certainty.
The following is an example of purifying upon my new method and for
the purpose of rendering the method perfectly clear, I will show how I deal with
semolina which would pass through a mesh of 16 threads per inch, but which
would not pass through a mesh of 18 threads per inch.
To purify such a class of semolina on my new method, I use my well-known
Victoria sieve purifier, and I clothe the sieve with gauze covering having
20 threads per inch, or of such a mesh as will prevent the semolina, feeding the
machine, from passing downwards through the sieve. I then cause the air current
passing upwards through the sieve to rise with such a velocity as will separate and
lift the semolina of lighter specific gravity upon the nozzle collecting tray placed
above the sieve. Such semolina of lighter specific gravity is then discharged by the
usual channels from the nozzle collecting tray as is well understood by millers.
The semolina of heavier specific gravity which remains upon the sieve is
discharged over the tail of the sieve.
In the above illustration I show how I divide the original feed into two distinct
samples of a different specific gravity.
In some cases I use several successive uprising air currents of varying intensity
upon the same sieve, and I am thereby enabled to separate the material feeding
the machine into three or more distinct samples of varying specific gravities.
Dated this 7th day of March 1895.
WM. P. THOMPSON & Co.,
Of 6 Lord Street, Liverpool, Patent Agents for the Applicant.
An Improved Method of and Apparatus for Purifying Grain,
Cereals, Wheat, Semolina, Middlings, Dunst, and the like.
I, JAMES HIGGINBOTTOM of 32, Seel Street, Liverpool in the County of
Lancaster, Milling 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 :—
My invention is for a new method of separating or purifying grain, cereals,
wheat, semolina, middlings, dunst and the like in machines having rotary or
vibrating sieves in which a gauze sieve surface is used having currents of air
passing in an upward direction through the same. In the present existing practice
such machines are arranged with a gauze sieve surface having meshes larger than
a part of the material which is passing to the machine to be treated, in other
words, the gauze covering on the sieve is arranged with a mesh sufficiently large
that a part of the feed material may pass through such mesh into a chamber or
receptacle below the sieves. The air currents are applied with such force or
intensity that the material as it is in the act of passing through the hole of the
mesh is met with an uprising current of air which is passing in an opposite
direction to the falling particles and in such a manner that at the instant of the
passage of a particle the speed of the uprising air current is intensified in passing
through the hole in proportion as the area of the hole is obstructed by the down-
ward passing particle. Thus, the current of air in passing through the hole

page_text: between the threads of the mesh and the sides of the passing or falling particle
itself is increased in velocity, and, as is well known in these machines, the air
currents can be set so that the velocity of the air current at the particular moment
described shall be just such as will allow a particle of a heavier specific gravity to
fall through the hole into the chamber below, but too powerful to permit a similar
size of particle of a less specific gravity passing through the hole. By such
method, a separation or purification is effected betwixt the particles, such separation
being made according to the velocity of the air currents and the differences
between the specific gravities of the particles. In this method of separation or
purification the sizes of the mesh and the velocity of the wind current are varied to
suit the size and nature of the particles, but in all cases, the separation or purifi-
cation is done by an uprising current of air passing through a hole and the purified
particles of heavier specific gravity passing downwards through the same hole,
whilst at the same time the uprising air prevents the particles of a lighter specific
gravity from falling through the hole and carries them into depositing surfaces
such as channels or trays of nozzles placed above the sieve.
It is obvious that in this the ordinary method of separation or purification, the
velocity of the air currents ascending through the holes in the mesh must not be so
great as will prevent the heavier particles from falling through the hole, and that
the velocity of the uprising air available for carrying away and depositing material
of a lighter specific gravity in the channels or nozzle trays above the sieve is
restricted or limited by the weight of the beavier particles which must be allowed
to fall through the holes in the sieve.
By means of my invention I am enabled to use an unrestricted velocity of
ascending air for the purpose of separating and depositing particles of a less.
specific gravity in the channels or nozzle trays placed over the sieve and I con-
sequently attain a more effectual and delicate separation-also I am thereby
enabled to make separations between particles which are of the same size and
shape but of a different specific gravity.
To effect this result, I make the meshes of the gauze covering of the sieve
smaller than the material to be separated; in other words, I arrange so that the
material to be separated or purified cannot pass through the meshes of the gauze
covering and cause the air currents to rise up through these smaller meshes with
a velocity sufficient to lift the particles of lighter specific gravity out of the
particles of heavier specific gravity on to a collecting tray of nozzles or channels
or other surfaces placed in a chamber or compartment above or contiguous to the
material moving over the sieve. I also make the sieve of a sufficient length so-
that the particles to be lifted have a length to travel under the action of the
uprising air current which is passed through the sieve such as is found to be
sufficient to accomplish the desired degree of separation. In other words, if a
particle entering the sieve arrives at one of these smaller holes and if the wind
rising through that particular hole fails to lift out the desired particle, such particle
must pass on to the next succeeding hole upon the sieve where it is again met with
a similar uprising current, so that if the particle to be extracted does not become
removed at the first or second or third hole over which it is passing, its removal
may be accomplished at some other point lower down the sieve, and my new
method enables me to bring the particle successively under the action of the air
current until it becomes removed of a certainty.
In some cases I place more than one set of collecting trays of nozzles and
chambers or compartments above the sieve in such manner that the material
moving on the sieve may be subjected to any desired velocity of air current in any
of the compartments for the purpose of separating material of a different specific
gravity in each compartment.
These objects are attained by the apparatus illustrated in the accompanying
drawings, in which―
Figure 1 is a longitudinal section of a machine;
T

page_text: Figure 3 is a transverse section of a portion of the machine on the line 2-2 of
Figure 2.
Like letters represent like parts in the drawings Figures 1, 2 and 3.
A is the framework or casing of the machine; B the hopper for the material to
be separated or purified. C the feed roller D, D' D2 are exhaust fans placed
above the sieve in the chambers or compartments E E' E².
F is a reciprocating sieve frame which is suspended by hangers to the frame A
and made to vibrate by means of the eccentric G. S is the gauze covered sieve.
NN N2 are trays of nozzles or channels placed over the sieve for collecting the
separated material. H H H are the channels through which the material is
discharged. I is the discharge for the overtails of the sieve. J is the discharge
box with hanging flaps therein arranged for the purpose of permitting the material
to be discharged and to prevent the air from passing. H³ are air tight partitions
between the compartments E E¹ and E2. H₁ are flexible air tight connections
from the partitions to the vibrating sieve.
The following is an example of separating or purifying upon my new method
and for the purpose of clearly explaining the method, I describe how I treat
semolina which will pass through Grits gauze silk having a mesh of 16 threads
per inch and which will not pass through Grits gauze silk having a mesh of
18 threads per inch.
To separate or purify such semolina, I clothe the sieve with Grits gauze silk
having a mesh of 20 threads per inch, or in other words of such a degree of
fineness of mesh as will prevent the semolina from passing downwards through the
sieve.
The semolina enters by the feed hopper B and is distributed over the sieve S
by the feed roller C. The semolina travels down the sieve and the exhaust
fans D D¹ D² cause an air current to pass upwards through the sieve with such a
velocity as will separate and lift the semolina of lighter specific gravity upon the
nozzle collecting trays N N N².
The semolina of heaviest specific gravity remains upon the sieve and it becomes
discharged over the tail I of the sieve through the discharge box J, to the outside
of the machine.
By revolving the exhaust fans D D1 and D2 at different speeds the air currents
rising through the sieve may be varied in each compartment, thus the material
separated and deposited on the nozzle tray N may be lighter in specific gravity
than the material separated and deposited in the nozzle tray N¹ or N2.
The air in compartment E enters the fan D as shown by the arrows on
Figure 2.
The fan discharges the air from thence to the outside of the machine.
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 system of separation or purification herein described by means of gauze
sieves or perforated surfaces and upward air currents in which the lighter.particles
1
110 1
1
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 system of separation or purification herein described by means of gauze
sieves or perforated surfaces and upward air currents in which the lighter.particles
are separated from the heavier particles upon the sieve and lifted into depositing
channels or trays or surfaces above the sieve without the passage of the heavier
particles through the sieve.
2. The improved apparatus for the purposes described in Claim 1, substantially
as described and shown on the accompanying drawing.
Dated this 15th day of August 1895.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.