Improvements in Apparatus for the Separation of Dust, Bran, Stones, or other like Impurities from Flour, Middlings, Semolina, Grain, Seeds, or the like.
Year: 1888

page_text: Date of Application, 13th Oct., 1888
Complete Specification Left, 13th Aug., 1889-Accepted, 12th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for the Separation of Dust, Bran, Stones,
or other like Impurities from Flour, Middlings, Semolina, Grain,
Seeds, or 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:-
This invention has for its object mainly the separating of dust, cellulose and branny
matter from flour, dunst middlings, semolina and the like, the separating of light
refuse from wheat or other grain, and the separating of wheat and other grain from
stones.
When applied to middlings purifiers having vibrating sieves as ordinarily
constructed, the invention is carried into effect as follows:-
A series of vibrating nozzles is fixed over the surface of the silk or metal covered
vibrating sieve and in close proximity thereto. These nozzles are hollow, and they
are either rectangular, circular or elliptical in cross section, and they can be made
with either straight or conical sides. I prefer to make them pyramidical or conical in
shape and to arrange them with their bases nearest to the sieve surface and to form
their sides with a slope of about 60 degrees on both their exterior and interior
surfaces, I also prefer to make the cone of such a depth that the area of the base is
about six times the area of the top.
An air tight vibrating partition of wood or metal is fixed close to the sieve surface,
and vibrates therewith for the purpose of firstly, carrying the said nozzles, secondly,
forming an air tight compartment above the sieve to receive the separated matter, and
thirdly for the purpose of automatically discharging the separated matter.
The pyramidical nozzles are attached by their bases to this air tight partition, and
the partition is provided with holes, opposite to and corresponding with the openings
in the bases of the nozzles and in air tight connection therewith. The nozzles can be
open at the top, hut I prefer to make them with a closed top and with a discharge
aperture on the side or sides close to the top.
When in work, the action of these nozzles is as follows:-
The air rising through the sieve surface, carries off the material to be separated and
enters the bases of the nozzles. After entering the nozzles, the air and the matter
contained therein acquires a gradually accelerated velocity, owing to the converging
sides of the interior of the nozzles. The velocity of the uprising air current is so
regulated that the heavier particles remain on the sieve surface, and the lighter matter
to be separated enters the base of the nozzles and is carried upwards by the
accelerating air current. The uprising air with its contained separated matter on
leaving the orifices of the nozzles expands and decreases in velocity. Owing to this
decreased velocity, the separated matter is deposited upon the upper surface of the air
tight partitions. After the air has passed through the nozzles, it is led away in the
usual well known manner by means of air trunks or fans.
The separated matter deposited upon the surface of the vibrating partition is carried
down by the vibratory motion to the tail or lower end of the same, and is discharged
therefrom by means of a vibrating spout or duct, and led away to the side or end of
the machine. Or it can be discharged into a worm box or a stationary hopper. Such
discharging device is fitted with an air tight apparatus to prevent the entry of the
outer air to the machine.
When the invention is applied to the separation of light refuse from wheat or seeds,
the vibrating sieve is clothed with suitable perforated metal, to allow the dust and
small dirt to pass through its meshes or perforations. The grain being treated passes
over the tail of the sieve and the light separated matter passes through the nozzle

page_text: orifices onto the upper surface of the vibrating partition and is discharged therefrom
as above described.
When the invention is applied to the separating of wheat or beans or other grain,
or seeds from stones, the wheat is lifted by the air current and deposited on the upper
surface of the partition, and the stones are discharged over the tail of the sieve.
Dated the 12th day of October 1888.
W. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in Apparatus for the Separation of Dust, Bran, Stones,
or other like Impurities from Flour, Middlings, Semolina, Grain,
Seeds, or the like.
I, JAMES HIGGINBOTTOM of 32, Scel 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 separating or purifying apparatus for the separation of
dust, cellulose, and branny matter from flour, dunst, middlings, semolina, and the like;
for the separation of light refuse from wheat or other grain; and for the separation
of wheat or other grain from stones.
As applied to purifiers for flour or fine middlings, (dunst) and to coarse middlings,
semolina, and the like, the invention has for its object the separation and deposition,
within the purifier itself, of the impurities carried off from the sieve surface by the
uprising air current, without the aid of cloth or similar straining mediums within the
purifier, or of stive rooms or dust collectors outside of or away from the purifier, and
the purification of the material is effected in a more perfect manner than has been
hitherto accomplished.
Cloth straining mediums within the purifier are objectionable, inasmuch as the
meshes become clogged or stopped up, and the machine takes more fan power because
the air must be increased in velocity and volume to overcome such stoppage. Also
such stoppage prevents the proper purification of the material in the machine.
Stive rooms or dust collectors outside of or away from the machine are also
objectionable because of the increased velocity and consequent volume of air required,
and also because of the increased risk of fire and the consequent increased premium
demanded by the Insurance Companies on account of such risk.
It is of great importance that the impurities carried away from the sieve surface by
the uprising current of air should, as far as practicable, be deposited within the
purifier itself, without the aid of the above subsidiary appliances and with as small a
fan power as is consistent with the proper purification of the material, and my present
invention is designed to accomplish these desirable objects.
The manner in which I carry my invention into effect is as follows, reference being
had to the accompanying drawings, in which :-
Figure 1 is a longitudinal vertical section through a middlings purifier constructed
in accordance with my invention.
Figure 2 is a transverse vertical section of the same.
Figure 3 is a plan, on a larger scale than that of Figures 1 and 2, of a portion of
the nozzle apparatus hereinafter more fully described.
Figure 4 is a section on the line xx of Figure 3.
In these:-
a is the outer case or framing of the purifier. A, is the ordinary inclined vibrating
sieve of the purifier, which is connected to the casing by air tight flexible connections a³,
and is vibrated in any well known manner, as by an eccentric a².
F is a flat plate or tray which is placed above the sieve A and is preferably vibrated
therewith, being also connected to the casing by air tight flexible connections a³. A

page_text: large number of small holes is made in the tray F, and each of these holes is fitted
with a tapered nozzle on the top side of the tray, these nozzles being distributed in a
regular manner over the whole area of the sieve, or over the active portion thereof
(that is, over such portion thereof as is under the influence of the uprising air
current). The open bases F' of the nozzles are preferably placed as close as
practicable to the sieve surface, while each of their upper or narrower ends opens by
a discharge orifice or orifices into a depositing compartiment H. The discharge
orifices are preferably placed as close as practicable to the sieve surface, and preferably
upon the side of the nozzle, as hereinafter described.
The compartment H is preferably kept in a partially exhausted state by a fan J,
which is capable of displacing a large volume of air having a comparatively low
velocity. The fan is driven in any suitable manner, as by a pulley J¹.
The mode of action is as follows:-
The material to be purified is fed on to the sieve through a feed hopper B of any well
known construction, and passes, by the vibration of the sieve, down towards the tail
end at of the latter. The material passing through the sieve is caught in a hopper or
hoppers C,while particles which are too large to pass through are discharged over the
tail end a, and pass to the outside of the machine in any well known manner.
The fan J draws up, through the sieve and the material thereon, a comparatively
large body of air, which has preferably just sufficient velocity or sustaining power to
lift the impurities (that is, the material to be separated) from the sieve surface, and
cause the same to enter the bases of the nozzles G.
As the air passes up through the nozzles, its velocity is rapidly accelerated, and its
sustaining power is thereby proportionately increased, partly by reason of the tapering
form of the nozzles, and partly because the total area of the nozzle exits G¹ is very
considerably smaller than the total area of the sieve surface, this comparatively great
reduction of area is due to the fact that a nozzle (by reason of its form) has the area
of its exit reduced in two dimensions, namely, both longitudinally and transversely.
The slowly moving body of air which passes through the sieve is thus, as it were,
transformed into a series of sharp upward puffs of air distributed in a regular manner
all over the active area of the sieve. The result of this rapid acceleration of the air is,
that practically the whole of the separated material which has entered the bases of the
nozzles is carried upwards and discharged into the compartment H, none being
permitted to fall back again on to the material on the sieve.
As the greatly subdivided and accelerated current of air (with its suspended
impurities) issues into the comparatively still (that is, slowly moving) atmosphere of
the partially exhausted compartment H, it undergoes a large amount of expansion or
dispersion, which greatly reduces its suspending power and causes it to deposit almost
the whole of the suspended impurities upon the upper surfaces of the nozzles and
upon the vibrating tray F. The vibration of the latter causes the deposited material
is discharged
to travel down to the trough fat the tail end of the tray, whence
through a vibrating spout C³ into a shute C on the outside of the machine, which
is also provided with counterbalanced air tight discharge doors c or their equivalent.
Also the greatly reduced total area of the nozzle discharge orifices, as compared
with the active sieve surface and as compared with the total area of the top surfaces
of the tray and nozzles, enables a comparatively large area to be provided on or over
the latter, for the expansion or dispersion of the air and the deposition of the
impurities.
Thus the deposition within the chamber H is so complete that nothing remains in
suspension but a very small amount. of the lightest and finest dust. This, as the air
ascends to the fan with a greatly reduced velocity, is retained and deposited within
the machine by means of any well known arrangement of vanes and baffle boards,
such as those shown in the upper part of Figures 1 and 2. The dust, deposited on
these vanes, slides off them, as it accumulates, into a conveyor trough, whence it may
be discharged automatically as described in my British Patent specification No. 6676,
dated May 18th, 1886.
The air issuing from the fan J may be discharged directly into the room where the

page_text: purifier is at work in a sufficiently pure state to be freely inhaled.
As an additional
precaution, I sometimes place a pocket D³ at the top of the machine, within which
any remaining particles of impurities issuing from the fan are deposited. With a
well designed and properly worked purifier, however, the amount of impurities
deposited in this pocket so. very small, that the latter becomes an unnecessary
adjunct.
.
The nozzles G are made of any suitable shape in sectional plan, being preferably of
the rectangular form shown, or of some form the length and width of which are
approximately equal. Their exit openings G¹ may be placed at their extreme upper
ends, but it is preferable to provide these upper ends with lateral openings, as shown,
and to make the top of the nozzle in the form of a curved, hood G³, as by this
arrangement the air, on issuing from the nozzles, is directed slightly in a downward
direction, and the deposition of the suspended impurities is thereby assisted.
The tray and nozzles are preferably made of some thin light material such as sheet
zinc, tin, etcetera, so that they add but little additional weight to the sieve.
Instead of vibrating the tray and nozzles with the sieve they may be vibrated
independently thereof. Or both tray and nozzles may even be made fixtures, in
which case travelling brushes, scrapers or other equivalent apparatus would have to
be provided for discharging the matter deposited on the tray. This latter arrangement
is not, however, generally desirable.
When arranged in parallel rows as shown in Figures 1 and 2, it is preferable to
place them with their exits G₁ facing towards the longitudinal axis of the machine,
except the row or two at the centre, the exits of which may face towards the lower
end of the tray. This arrangement facilitates the movement of the deposited material
to the lower end of the tray, and it also prevents the said material from being blown
against the glazed sides a of the machine through which the working of the nozzles
can be inspected at all times.
The nozzles are preferably tapered on all sides, but they may, if desired, be tapered
only upon a certain number of them. These sides, which may be either straight or
curved, are, by preference, made to taper at about an angle of 60° from the horizontal,
as it is found in practice that a less inclination than this offers too great a retardation
to the passage of the air up the nozzles, while with a greater inclination the rate of
acceleration of the air up the nozzles is diminished, in either of which cases an
additional fan power is required for a given degree of purification.
As before mentioned, the acceleration of speed in the nozzles, upon which the
efficient working of my invention in great measure depends, is due partly to the small
total area of the exits G¹ as compared with the total area of the sieve. With a well
designed nozzle arrangement, such as described, it is practicable to reduce the total
area of the exits G to almost any extent from to or even less than of the
total sieve area, and this without running any risk of choking from accumulation of
impurities round the edges of the exits, and without introducing any other elements
of bad design, such as too great a vertical length in the nozzles, too little an inclination
from the horizontal in their sides, etcetera. In purifying semolina, middlings and
dunst, find that with nozzles such as shown, very good results are obtained when
the total area of the exits is about of the total sieve area, the exits being preferably,
at no point less than of an inch wide. The exact ratio of the areas, and in fact the
precise proportions and arrangement of the nozzles and the speed of the fan generally,
depend greatly upon the nature of the material under treatment, and the degree of
purification required.
The lower ends F of the nozzles are by preference placed as close as practicable to
the sieve, say at a distance therefrom of about g of an inch. The lips or edges of
the exits are also preferably placed as close as practicable to the bases of their nozzles,
say at a distance of g of an inch. By thus designing the nozzles, the distance which
the impurities have to be lifted from the sieve, before being discharged on to the
tray F, is reduced to a minimum, and this tends greatly to reduce the fan power
required.
This reduction of fan power is a great advantage, not only on account of the

page_text: economy in driving power, and the increased facilities offered for the deposition of the
impurities in the compartment H as before described, but also because there results a
reduced velocity in the air passing up through the machine, and such air is thereby
more perfectly under control and its action is more equable. With a purifier constructed
as above described and having a sieve of about 80 inches long by 30 inches wide, I am
enabled, when working upon dunst, to use an ordinary exhaust fan of common well
known construction, about 36 inches diameter and 22 inches wide, running at about
100 revolutions per minute.
The regular distribution of a large number of nozzles such as G, over the sieve, also
results in a more regular distribution of the air action over the sieve surface, and
consequently, in a more regular purification of the material.
In addition to the improved deposit of the separated impurities, above referred to, I
am also enabled, by my invention, to obtain a more rapid and better separation of the
said impurities, and I require a much less total volume of air for accomplishing a
given degree of purification than is required in any purifier hitherto known to me.
When the invention is applied to the separation of light refuse from wheat or seeds,
the vibrating sieve frame may be clothed with suitable perforated metal in lieu of the
ordinary silk gauze. This perforated metal allows the heavier dust and small dirt to
pass through its perforations. The grain or seed, after being treated, passes over the
tail of the sieve, and the light separated matter passes, as before described, through
the nozzle orifice G₁ on to the upper surface of the vibrating tray F, and is discharged
therefrom through the shute C
When the invention is applied to the separating of wheat or beans or other grain or
seeds from stones, the wheat, etcetera, is lifted by the air current, (which is, of course,
much more powerful than in the previous cases) and is deposited on the upper surface
of the tray F, the stones being discharged over the tail of the sieve as before.
In cases where the nature of the material or the character of the work will not
admit of the employment of an exhaust fan, any other suitable aspirating or blowing
apparatus may be employed.
Although, in the preceding description of the invention, the tray and nozzles have
been set forth as placed close to the sieve surface, it will be obvious that they might
also be located within the machine at any suitable distance from the siove, with the
object of eliminating from the air the matter carried off from the material on the
sieve. As a general rule, however, it will be found that the best results are
obtainable when the bases of the nozzles are placed as close as practicable to the
sieve.
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 combination of parts forming separating or purifying apparatus of the kind
described, in which is employed a horizontal or nearly horizontal tray, partition, or
diaphragm placed a short distance above a sieve and pierced, honeycombed, or
provided with numerous conical or pyramidal orifices, whereby the exit spaces for air
are narrowed to a desirable minimum both longitudinally and transversely, and thus a
maximum of contraction and slope of passage is secured with a minimum of height
and obstruction, for the purposes described.
2. In apparatus employed for the separation of dust or other like impurities from
flour, middlings, semolina, grain, seeds or the like, and constructed as herein described,
the use of a series of nozzles of forms such as are herein before mentioned for the
prposes specified.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.