Improvements in or Appertaining to the Separation of Bran, Cellulose, or the like from Semolina, Middlings, Dunst, Flour, or Similar Material.
Year: 1889

page_text: Date of Application, 16th Jan., 1889
Complete Specification Left, 16th Oct., 1989-Accepted, 23rd Nov., 1889
Improvements in or Appertaining to the Separation of Bran,
Cellulose, or the like from Semolina, Middlings, Dunst, Flour,
or Similar Material.
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:-
This invention relates to certain improvements in the method and apparatus for
separating bran, cellulose, or the like from semolina, middlings, dunst, flour or
similar material.
At the various stages of the modern flour milling systems now in use, there are
many intermediate products. These are known in the trade by the various terms
of break meals, semolina, middlings, dunst, and flour, and they are of varying
degrees of fineness or coarseness according to the meshes of the wire or silk by
which such products have been separated.
These products are made in the breaking down and reducing of the wheat and
each product consists of a mixture of,
1st. The white interior of the wheat.
2nd. The exterior or skin of the wheat, and
3rd. The germ of the wheat.
Also, some of the particles of each product when closely examined are found to
consist of thin flakes from the outside of the skin of the wheat. Other particles
consist of the outer skin with a portion of the white interior adhering to the
same. The bulk of the particles consists of the white interior of the wheat.
The purpose of the invention may be explained in the simplest manner by
describing its application to the purification and separation of one of the above
products, namely, to the semolina from the break meal obtained in breaking down
the wheat, such semolina having been separated or passed through, say for example,
a mesh of 18 per inch, and having passed over a mesh, say, of 50 por inch, is passed
on to the sieve of a purifier having say, a mesh of 40 to the inch at the head
end and gradually becoming coarser, say to a mesh of 30 per inch, at the tail
ond. The product as it passes on to the sieve consists of a mixture of, 1st, coarse
white semolina, 2nd, fine white semolina, 3rd, particles of semolina having the
outer skin adhering to them, 4th, loose flakes of the outer skin, 5th, the germ of the
wheat, and 6th, particles of white semolina free from skin but of a flat or irregular
shape.
In a purifier as ordinarily constructed, the above mixture, as it passes over the
sieve, has nearly all the loose flakes of skin separated by the air current rising
through the sieve. The finer semolina and gorm, and a small portion of the
semolina with skin adhering to it (the semolina forming the bulk of this latter
item) pass through the sieve. The coarser semolina and germ, and the remainder
of the semolina as above enumerated, pass over the tail of the sieve, where the bulk
of any light matter still remaining is separated by an aspirator.
It will be seen that the defect in this process is that a considerable quantity of
the semolina with adhering skin and also the flat or irregular semolina goes into the
tails and has either to be separated subsequently from the coarse semolina and germ
or to be again broken down with them.
Now the object of my invention is to separate such impure semolina, and any
remaining loose skin flakes, from the rest of the tails in the same purifier.
The above semolina with adhering skin and the flat or irregular shaped semolina
would have nearly all gone through the meshes of the sieve and intermingled with
the purified finer semolina and germ, had there been no air current going up through
the sieve. Now according to my invention, I arrange the sieve of the purifier in
CD
837

page_text: such a manner that a portion of the sieve surface at the tail end of the sieve is not
under the action of the uprising air current; consequently, a large portion of the
semolina with adhering skiu, also the flat or irregular semolina, passes through this
part of the sieve before reaching the tail, and is led away by a special vibrating spout
attached to the sieve or other contrivance to any convenient point.
The sieve may be made of such a length that the purified finer semolina and
germ pass through it before reaching the above dead sheet or sheets at the tail.
In some cases I may use two or more of the "dead sheets" (i.e. sheets on the
sieve on which thore is no upward wind current), and I may attach separate
collecting troughs or ducts to carry away the material coming through such dead
sheets. Also, I may place such dead sheets alternately with the sheets having the
upward current of air in such a manner as to cause a better separation of the
impure semolina.
The object of the alternate dead sheets is to enable me to separate the smaller
impure matter before it reaches the tail end dead sheet of the sieve."
It will be obvious that the invention is also applicable to the treatment of Break
meal, middlings, dunst, or flour, or similar products whether obtained from wheat
or otherwise.
Dated this 15th day of Jana 1000
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or Appertaining to the Separation of Bran,
Cellulose, or the like from Semolina, Middlings, Dunst, Flour,
or Similar Material.
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 :—
This invention relates to certain improvements in the method of and apparatus
for sieving, separating or purifying granular, pulverulent or other like material, in
cases where such material is passed, during treatment, over a horizontal or inclined
vibratory sieving surface which is under the action of an uprising current of air or
other fluid. The invention is especially applicable to the separating of bran, cellulose
er the like from semolina, middlings, dunst and flour.
At the various stages of the modern flour milling systems now in use, there are
many intermediate products. These products are known in the trade by the various
terms of break-meals, semolina, middlings, dunst and flour, and they are of varying
degrees of fineness or coarseness according to the meshes of the wire or silk, etcetera,
by which such products have been separated.
These products are made in the "" breaking-down” and reducing of the wheat,
and each product consists of a mixture, in varying proportions, of
1st. The white interior of the wheat.
2nd. The exterior or skin of the wheat.
3rd. The germ of the wheat, both broken and whole (or unbroken).
4th. Some of the particles of each product, when closely examined are found to
consist of thin flakes or layers of branny matter from the outside of the skin of the
wheat.
5th. Other particles consist of the outer skin or bran of the wheat with a small
portion of the white interior of the wheat adhering to the same.
6th. Other particles consist of cellulose or fluffy matter which is disengaged in
breaking down the white interior of the wheat.
7th. Other particles consist of branny dust, which has been produced during the

page_text: breaking down of the wheat, from the abrasion of the outer skins of the wheat and
branny and germy dust from the torn or broken edges of the wheat skins and from
the torn edges of the broken germs.
The bulk of the particles of the flour, dunst, middlings, and semolina products
consists of the good material, namely, the white interior of the wheat mentioned in
paragraph No. 1.
In the ordinary processes of modern milling, it is usual to separate the good
white material in the dunst, middlings and semolina from the impure material
therein as perfectly as possible before such good white material is reduced into or
used as flour for bread-making purposes, and my invention enables this to be done
more perfectly than hitherto.
My invention is also applicable for separating and purifying the flour itself, namely,
for removing the very fine impurities which have become incorporated with the
flour, and which have passed through the same mesh as the flour.
To accomplish these purposes, millers use the well known sieve purifier, and the
object of this invention may be explained in the best and simplest manner by
describing its application in detail to the purification of one of the above named
products, namely, to the semolina produced from the break-wheel which has been
obtained in breaking down the wheat.
Referring to the drawings:
Figure 1 is a longitudinal vertical section of a purifier provided with an apparatus
constructed in accordance with my invention.
Figure 2 is a transverse section of the same on the line ≈ x, Figure 1.
The abovementioned semolina product having been separated or passed through,
say for example, a mesh of 18 per inch, and having passed over a mosh, say of
50 per inch, is, in ordinary practice, passed on to a sieve A¹ A² A³ A* of a purifier,
having a mesh of 40 per inch at the head end a, and gradually becoming coarser,
to a mesh of 30 per inch, at the tail end a¹. Such gradations of covering
say
being preferably in four distinct sections, say as follows
1st. Section of sieve, A¹, 40 meshes per inch.
2nd. Section of sieve, A³, 34 meshes per inch.
3rd. Section of sieve, A³, 34 meshes per inch.
4th. Section of sieve, A', 30 meshes per inch.
Also the overtails are usually aspirated after leaving the sieve by an aspirator
such as B.
Such semolina product is passed, at a suitable rate of feed, through a feed
hopper C on to the sieve of the purifier, and its composition, as it is fed on to the
sieve, consists of particles which are of the above described kinds, and they are also
of varying sizes and shapes. The size of the largest and the smallest of each kind
of the particles is regulated by the size of the meshes by which the semolina has
been previously separated. It is obvious that there are all sizes of particles of each
kind of material, between the limits of those particles which will not pass through
a mesh of 50 per inch and those particles which will pass through a mesh of 18 per
inch.
For clearness of description, it may be broadly stated that such semolina product is
made up of finer and coarser particles of each kind of material, as follows
A. White semolina.
B. The broken and unbroken germ of the wheat.
C. Fine particles of white semolina, free from bian or skins, but of an irregular or
flattened shape, of a quality inferior to sample A, and of a less specific gravity.
D. Particles of the outer skin or bran of the wheat. having a small thin portion
of the white interior of the wheat adhering to the same.
E. Particles of the outer skin or bran of the wheat free from the adhering
white matter.
F. Particles of loose and light flakes of the outer layers of the skins of the wheat
as above described in paragraph No. 4.
G Particles of Auffy matter namaly cellulose and dust from the hran and

page_text: germ, and from the white interior of the wheat as above described in paragraphs
Nos. 6 and 7.
The sample A consists of good material.
The sample B consists of germ which cannot be eliminated by the action of the
air currents of the purifier, because its specific gravity is nearly the same as that
of the white semolina.
The samples (CDEFG) constitute the impurities which require to be removed,
and it is the miller's object to accomplish the removal of the same as efficiently as
possible.
In a purifier having, as ordinarily constructed, a vibrating sieve (A' A' A³ A')
and an exhaust fan D adapted to produce uprising air currents through the meshes
of the vibrating sieve, and having also a series of channels or a tray of nozzles E F
or other equivalent device over the sieve for collecting and removing the impurities
which are separated and deposited thereon by such air-currents-the action of the
machine is as follows:-
The semolina feed, consisting of finer and coarser particles of the above mixture,
passes on to the sieve at the head end a thereof, and as it gradually travels towards
the tail end a' thereof it is under the combined action of the vibratory motion
of the sieve and the uprising air current, which conjointly cause the particles of
impurities which are of a less specific gravity than the good white material to
accumulate near the top of the material on the sieve, while the good material passes
down through the meshes of the sieve, and is thereafter collected.
When treating, in ordinary purifiers, the mixed material as enumerated and
described in the aforesaid paragraphs headed A, B, C, D, E, F, G, it is found, in
practice, that the air current, rising through the material as it passes over the
sieve, rapidly removes a portion of the light loose flakes of the outer layers of skin,
also a portion of the lighter parts of the fluffy matter, as described under the
paragraphs F and G. These flakes and fluffy matter are of a very light nature,
and they are carried upwards by the air, and-where channels are used as aforesaid-
such light material is deposited in said channels and carried away by the same; or
it is carried through the nozzles E and deposited on the upper surface of the collecting
tray F; or in cases where channels or nozzles are not used-this.light material is
carried away by the fan and deposited outside the machine in stive rooms, cyclones
or dust collectors, as is well understood by millers; or, in some cases, such material
is collected inside the machine by means of textile dust collectors, or other equivalent
devices.
It is also found, however, in practice, that the largest portion of the particles of
impurities (C, D; E, F and G) are too heavy in character to be lifted by the air in
the ordinary course of working on to the collecting tray F, (or other equivalent
device) and also that such heavier particles or impurities are carried over the surface
of the sieve and passed over the tail a' thereof, although the largest portion of such
particles of impurities would readily fall through the meshes of the coarser tail
sheet A of the sieve, were it not that they are prevented from so doing by the
sustaining power of the uprising current of air.
The reason of this is, that, when the air current is so adjusted as not to prevent
the good white semolina from freely falling through the meshes of the sieve, its
strength or velocity is then sufficient to prevent the heavier particles of impurities
from also falling through the meshes of the sieve, but its strength or velocity is not
sufficient to lift the whole of such impurities on to the collecting tray of
nozzles EF, or on to the channels, where such are employed. In practice, it is
found that the heaviest of the impure material mixes with the largest of the white
semolina and germ, which is passed over the tail of the sieve, and thus it becomes
necessary to re-treat the material which has passed over the tail of the sieve.
Now by my invention, I am enabled to accomplish, within the purifior itself, the
removal or separation of the greater portion of these heavier impurities and to prevent
the same from becoming mixed with the coarse good material, which passes over the
tail of the sieve.

page_text: To effect the above result, I arrange the sieve (A' A² A' A') of the purifier in such
a manner that one or more sections (say section A³) of the sieve surface is not
under the action of the uprising current of air. Consequently, a large portion of
the heavy impurities (consisting mainly of the finer particles therof), passes through
this part of the sieve before reaching the tail, and is led away by a special hopper or
spout H or other contrivance, to any convenient point. I also give the name of "dead
sheet" to this inactive section (A³) of the sieve, because it is not under the action
of the uprising air.
According to the quantity of feed per hour, I make the sieve of such a length,
and of such a size of mesh that the purified finer semolina and germ pass through
the meshes of the sections A' and A' before reaching the above named dead sheet A²,
and I make the dead sheet of such a length and size of mosh, that the finer portion
of the heavier impurities which have been sustained by the air current, while
travelling over the sections A and A2, will pass through the sieve when the said
particles reach or arrive at the dead sheet section A².
I may place the lead sheet at the extreme tail end of the sieve, or in some
cases may use two or more of the dead sheets on which there is no upward air
current, and I may attach separate collecting hoppers or spouts H to carry away
the material coming through such dead sheets.
Also I may place such dead sheets alternately with the active sheets (namely,
those which are under the influence of the upward current of air) in such manner
as to cause a better and more complete separation of both small, medium sized,
and large heavy impurities.
I may employ any suitable device to prevent the passage of the uprising current
of air through the dead sheet (or sheets). For instance, I may box off that portion
(or portions) of the purifier immediately below such dead sheet (or sheets), so
that the air current caused by the fan ceases to act or such portion (or portions)
of the sieve. I prefer, however, to attain my object as in the machine shown in
the drawings (Figure 1), namely, by simply placing an impermeable diaphragm J
of metal, or of other suitable substance impermeable to the air, over the sieve and close
to the surface thereof.
It will be obvious that the invention is also applicable to the treatment of Break
meal, Middlings, Dunst, and Flour, or to the treatment of similar products of
a granular or pulverulent nature, whether obtained from wheat or otherwise.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is
The manufacture and use in a sieving, separating or purifying apparatus of the
kind described, of a horizontal or inclined vibratory sieve having one or more
"active" sections, or sections under the influence of the uprising air current succeeded
by one or more "inactive" sections or "dead sheets" of sieve surface which are cut
off from or hardly at all under the influence of the uprising air current, substantially
as and for the purpose set forth.
Dated this 15th Ontahan 1880
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.