Improvements in Apparatus or Machinery for Purifying Semolina.
Year: 1886

page_text: PROVISIONAL SPECIFICATION.
Improvements in Apparatus or Machinery for Purifying Semolina.
I HENRY MACDONNELL of Castlegate House, Stockton-on-Tees, in the County of
Durham, Miller, do hereby declare the nature of this invention to be as follows:-
My Invention relates to the arrangement of mechanism and chambers forming a
machine or apparatus for separating the useful particles of such materials as semolina
from fibrous and fluffy impurities of lighter weight in the manner known as the
gravity process, my object being to extend this process so as to subject the material
under treatment to the repeated action of currents of air until the useful particles are
separated from the lighter impurities more completely than is effected by machines or
methods at present in use.
At the same time I construct the apparatus so as to be
self-cleaning in its various parts to abstract from the air before leaving the apparatus
the dust absorbed in its passage through the purifying chambers and also to, increase
the control over the process by facilities for inspecting the interior of the principal
purifying chamber and for adjusting its sectional area so as to increase or diminish
the velocity or force of the currents of air passing through it.
A purifying apparatus constructed according to my invention consists of a series
of chambers fitted up as aspirating chambers for the passage of vertical currents one
of which may be described as the principal purifying chamber and has the outer or
front side transparent for the inspection of the process, this side is fitted into the
casing by a leather or other flexible air tight material so that the sectional area of the
chamber may be contracted or enlarged as a means of regulating the force of
the draught; the other chambers are auxiliary purifying chambers for repeating the
J
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page_text: aspirating process upon the secondary semolina lifted over from the principal chamber.
In addition to these a chamber is provided which forms a receptacle for the fibrous
and fluffy impurities which have been carried over from the purifying chambers and
contains a filtering apparatus for abstracting from the air passing out of the apparatus
the dust absorbed in the purifying chambers. The apparatus also contains the means
for conveying the material from the spout of the semolina sizer to the principal
purifying chamber, the semolina being separated from the rough tailings by passing
through a sieve constructed in the well known manner of an oat-meal sieve, in which
the application of a vibratory motion coupled with a suitable inclination in the position
of the sieve carries the rough tailings over the end of the sieve and the semolina
through the sieve which is preferably of perforated zinc as being less chokable and
more readily cleaned than silk or woven wire cloth; the rough tailings do not enter
the purifying chambers intended for the semolina but are received into a channel at
the lower end of the sieve and conveyed into a separate aspirating chamber attached
to the apparatus where an upward current relieves them of all light and fibrous
particles. The semolina on passing through the sieve is received into a channel
beneath and conveyed to the principal purifying chamber; this may be effected by
any suitable means such as the application of a vibratory motion coupled with a
suitable incline of the channel as already described with reference to the sieve, the
channel and the sieve being when desired connected together and may for structural
compactness be fitted up within the purifier casing for this purpose.
The semolina is preferably delivered into the lower part of the principal purifying.
chamber where it meets and is lifted up by an upward current of air; a feed roller
revolving in contact with an automatic feed gate being provided in a suitable position
with reference to the semolina inlet to supply this in a thin continuous stream across
the entire width of the chamber and to prevent air from being sucked through to
disturb the upward current inside the purifier.
.
The auxiliary purifying chambers are arranged in any position with reference to
the principal purifying chamber and with reference to each other which may be found
convenient for carrying the aspirating process from chamber to chamber as one
continuous operation in the following manner :-
A continuous ascending current is induced through each aspirating chamber by a
fän or other means connected to or communicating with the purifying apparatus, the
velocity or force of the current being regulated in the principal purifying chamber by
the outer or front side being fitted in leather or other flexible air tight material so as
to be adjustable in position with reference to the other sides, whereby the passage for
the currents of air is increased or diminished. Currents of air are admitted to the
auxiliary chambers through openings at either end of a horizontal tube provided at
the lower part of each chamber and extending to the outside air, the quantity and
velocity or force of which may be controlled by slides or valves of any suitable
construction for reducing or increasing the area of the inlets or apertures provided in
the tube. The material under treatment as it is fed into the principal purifier is lifted
up by the ascending current of air which is strong enough to carry the light fibrous
particles over into the next chamber, whilst the heavier particles of pure semolina
again fall down a convenient receptacle placed below the course of the upward current.
The material carried over from the principal purifying chamber into the first auxiliary
chamber is again subjected to an ascending current of air, the operation being repeated
in a second auxiliary chamber and so on until every particle of semolina has been
extracted from the lighter fibrous and fluffy material which is carried over from the
last auxiliary purifying chamber into another chamber provided for its reception.
As the semolina accumulates in the auxiliary purifying chambers it is collected and
removed by any suitable means such as worm conveyors revolving at the bottom of
each chamber, this method having the advantage of forcing the material through an
outlet in such a manner as to prevent any admission of air to disturb the aspirating
process, the fibrous and fluffy impurities may also be removed from the chamber in
which they accumulate by the same means as is employed in the auxiliary purifying
chambers.

page_text: The currents of air emerge from the purifying chambers impregnated with dust. In
order to abstract this dust from the air before discharging it from the apparatus,
I provide in a suitable position in the upper part of the last chamber of the apparatus
an air filter consisting of an endless band of fibrous material revolving on rollers so as
to intercept the passage of the air from the apparatus, the fibrous material on the
outer surface of the endless band takes up the dust from the air and carries it down
into the fibre and fluff chamber into which it falls from the filter from the action of a
spring and suitable knocker continuously operating upon the fibrous material of the
filter.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus or Machinery for Purifying Semolina.
I, HENRY MACDONNELL, of Castlegate House, Stockton-on-Tees, in the County of
Durham, Miller, 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 relates to the arrangement and combination of chambers and their
requisite appliances forming a machine or apparatus in which the useful particles of
such materials as semolina can be separated from the fibrous and fluffy materials of
lighter weight, in the manner known as the gravity process.
The objects of my invention are, to subject the material under treatment to the
action of upward currents of air, until the useful particles are separated from the
lighter impurities more complety than is effected by machines or methods at present in
use; and I render the apparatus as perfectly adapted to its purpose as possible, by
making it self-cleaning and self-discharging; by abstracting from the air before
leaving the refuse chamber, the dust with which it becomes impregnated in its passage
through the aspirating chambers; by providing facilities for inspecting the interior
of the principal aspirating chamber, and by providing means for regulating and
adjusting the velocity and force of the currents of air in each of the aspirating
chambers.
In constructing a purifying apparatus according to my invention I connect together
within one casing or machine a series of chambers leading from one to another so as to
form one system in which I purify the finer semolina; the first of these chambers may
be termed the principal aspirating chamber, the intermediate chambers, of which there
may be one or more, may be termed the auxiliary aspirating chambers, and the last
chamber of this series is the refuse chamber. In addition to this system of chambers
I provide, if required, within the same machine or apparatus, and leading into the
same refuse chamber another aspirating chamber, in which I purify the coarse
semolina or rough tailings.
A continuous ascending current of air is induced by suction in each aspirating
chamber by a fan or other effective means communicating with the apparatus, the
force or velocity of which is separately adjusted in each chamber to the requirements
thereof.
And in order that my invention may be fully understood, I will now proceed
particularly to describe the same and for that purpose shall refer to the accompanying
drawings, in which a sectional view taken longitudinally through the apparatus is
illustrated in Fig. 1; a,transverse sectional view taken on line AA of Fig. 1. is
illustrated in Fig. 2; and another transverse sectional view taken on line B B of
Fig. 1. is illustrated in Fig. 3. In the system of chambers for purifying the finer
semolina, a is the principal aspirating chamber, b and c are the auxiliary aspirating
chambers, d is the refuse chamber, e is the separate aspirating chamber for purifying
the rough tailings and leads by a separate passage into the same refuse chamber d.
My object in this arrangement of chambers is to secure the advantage of being able

page_text: to feed the rough tailings into the lower part of the chamber e, and the finer semolina
into the lower part of chamber a to be lifted up by currents of air by which means
these materials are acted upon by ascending currents of air for a longer period, and
are consequently more effectively purified, than when the material is fed in from the
top against the current of air. In order to effect this the material to be purified is
discharged from the spout of the semolina sizer or separator into the sieve f, which
may be constructed in the well known manner of an oat-meal sieve, or in some other
equally effective manner by which a vibratory motion combined with a proper
inclination of the sieve carries the rough tailings over the end of the sieve into the
channel e¹, whilst the finer semolina passes through the sieve into the hopper a¹; the
sieve is preferably of perforated zinc as being less chokeable and more readily cleaned
than when made of silk or woven wire. The rough tailings are fed from the channel e¹
which is suitably inclined and vibrates with the sieve f for this purpose into the lower
part of the chamber e and are lifted up the chamber by a current of air which is
strong enough to carry the lighter impurities over to the passage leading to the refuse
chamber d, whilst allowing the heavier useful particles to fall down into a suitable
receptacle placed below the influence of the current; at the same time the finer
semolina is fed from the hopper a¹ into the lower part of the chamber a, and is
similarly carried up by a current of air which is strong enough to carry all but the
heavier particles over to the auxiliary chamber b, the heavier particles descending into
a receptacle provided below as in the case of the rough tailings; the lighter material
carried over to the chamber b, again encounters a vertical current which again carries
all but the heavier particles over to chamber c, where the process is repeated the
heavier particles in each case descending to the lower part of the auxiliary chamber,
which unlike the principal chamber a must be closed in at the bottom, by this process
the useful particles are separated from the fibrous and fluffy impurities which are
finally carried over into the refuse chamber d. In order to make the apparatus self-
cleaning, worm conveyors 9 are provided in each of the auxiliary chambers and the
refuse chamber d all of which may be driven by the same endless band, and which
convey the material which would otherwise accumulate in each of these chambers into
spouts or down comers in such a manner as to prevent the outlet for the discharging
material from forming an inlet for air to disturb the currents inside; for the same
reason special means such as a feed roller and an automatic feed gate should be fitted
to the principal chamber a, so that air cannot be sucked into this chamber from the
hopper a', as the semolina is fed in; it is also an advantage to construct this feed gate
so as to deliver the semolina in a thin continuous stream across the entire width of
the chamber a; if requisite the same provisions should be made for feeding the rough
tailings into chamber e. In the refuse chamber d, I provide in a suitable position an
endless brush passing over pullies ¹², this endless brush is faced on its outside.
surface with suitable fibrous material such as a series of resilient tufts of a kind
suitable for taking up the dust from the air before discharging the air from the
apparatus, the endless brush is fitted up to travel at an angle with reference to the
top of the chamber so that the air in passing out impinges upon the ascending surface
of the brush and parts with its dust, which dust is carried down by the brush to the
lower part of the refuse chamber and is discharged by the worm conveyor g with the
rest of the refuse.
The brush is preferably assisted in discharging the dust it has brought down by the
action of the knockers k¹ fixed in position as illustrated in Fig. 3, one of which
bends each tuft passing over it so as to cause it to rebound against the other. In
order to inspect the working of the aspirating process, I make the outer or front side
of the chamber a of glass or other transparent material; and in order to regulate and
adjust the velocity and force of the currents in the aspirating chambers, I effect this
in the principal chamber a by enlarging or contracting the passage for the currents
to pass through it a convenient way of effecting this is to fit the outer or front side
into leather or other flexible air tight material, and to secure it in any required
position by means of the set screws 1. The same means may be applied for regulating
the air current in the aspirating chamber e.

page_text: In the auxiliary chambers b and c which are closed in at the bottom, the velocity or
force of the current must be effected by other means, such as for instance by admitting
the currents of air through the horizontal tubes 61 c¹ extending into the outside air
and fixed in each chamber in the manner illustrated in Fig. 1. in which the opening or
apertures for admission of the air are controlled by a slide.
The baffle boards m are provided to assist in regulating the direction and distribution
of the currents of air, the position and arrangement of them being purely a matter of
judgement.
It is of course obvious that as the great feature of my invention is the way in
which I subject the semolina to the action of ascending currents of air, the apparatus
can be varied in its mechanical details and general design and the system of chambers
for effecting this purpose may be modified both in their number and relative positions
without departing from the nature of my invention and that portions of the apparatus
may be dispensed with in certain cases, as for instance, the apparatus may be con-
structed to purify the finer semolina only, leaving the rough tailings to be otherwise
disposed of, or the apparatus for filtering the air may be dispensed with in cases where
the condition of the discharged air is of no importance, or the front or outer side of
the principal purifying chamber may be neither transparent nor adjustable if not so
required.
Having now described the nature of my invention and in what way the same may
be carried into effect, what I claim is :—
Firstly In the construction of a semolina purifier, the arrangement or combination
of a system of chambers consisting of a principal aspirating chamber leading into
auxiliary aspirating chambers and finally into a refuse chamber so that the material to
be purified is first fed into the lower part of the principal chamber, and is afterwards
aspirated in one or more auxiliary chambers, substantially as and for the purpose as
hereinbefore described with reference to the accompanying drawings.
Secondly-The combination of the aspirating chamber e for purifying rough
tailings with the system of chambers for purifying the finer semolina, substantially as
described with reference to the accompanying drawings.
Thirdly-The means employed for regulating the force or velocity of the currents
of air in the open bottomed aspirating chambers a and e by enlarging or contracting
the passage therefor, substantially as described.
Fourthly-The employment of an air filter in the refuse chamber in combination
with the general arrangement of the purifying chambers, substantially as and for the
purpose as herein before described.
Fifthly The arrangement and combination of parts constituting an apparatus for
purifying semolina, substantially as hereinbefore described and illustrated in the
accompanying drawings.