Improved Method of and Apparatus for Drying, Cleansing, and Sifting Grain, in part applicable to Sifting or Separating Flour, Meal, and the like.
Year: 1890

page_text: Date of Application, 21st Feb., 1890
Complete Specification Left, 17th Dec., 1890-Accepted, 7th Feb., 1891
PROVISIONAL SPECIFICATION.
Improved Method of and Apparatus for Drying, Cleansing, and
Sifting Grain, in part applicable to Sifting or Separating Flour,
Meal, and the like.
I, HENRY SMITH, of 5, Queen's Place, Pulteney Road, Bath, in the County
of Somerset, Miller, do hereby declare the nature of this invention to be as
follows:-
This invention consists, in an improved method of and means for drying and
cleansing grain and separating the same from seeds, dirt and other refuse. It is
also, in part, applicable to sifting flour, meal and other like pulverulent
substances.
.
The grain to be treated is placed upon a slab or table of stone in the face
of which are grooves. Over this table works a pair of endless chains to which
are fitted brushes and strips of wood placed transversely between the chains.
The outer faces of the wood strips are shod with metal plates perforated or
grooved.
By these strips and brushes which bear on the face of the table, earth adhering
to the grain is detached therefrom and, as also any like refuse otherwise mixed
with the grain, is reduced in size.
The grain and refuse are together impelled along the face of the table at intervals
in which are apertures covered with a grating the meshes of which are sufficiently
small to prevent the grain from passing through.
A pro-
The gratings are adjustable and are lowered as the stone table wears.
portion of the refuse passes through the gratings and such as is not thus removed is
swept with the grain by the brushes to a shute by which the grain and accompanying
refuse are conducted to an endless band of sieves travelling round toothed wheels
fixed at opposite ends of a chamber.
This band is composed of a series of perforated trays arranged step-wise and
hinged to a pair of pitch chains.
As they travel the trays are caused to vibrate by passing the chains over a
serrated or notched bar situated at each side of the band of sieves, or by passing
the chains over rollers placed at intervals in a bar at each side.
As each sieve passes round the toothed wheel at one end it is brought into forcible
contact with the preceding sieve. The impact thereby obtained serves to dislodge
any grain or other substance which may be adhering to the sieves. The same
effect is also produced as the band passes round the toothed wheel at the
other end.
The trays, which are furnished at each side with raised guards to prevent the
grain from leaving them thereat, are adjusted at an inclination which assists to keep
the grain constantly in motion and to transfer it from one tray to the other.
Arranged around the series of trays and caused to travel in contact therewith and
in the same direction is an endless band of brushes by which the grain is further
agitated and the operation of sifting assisted.
By means of an exhaust fan a current of air is made to pass through the
perforations in the travelling sieves or trays and is regulated by a valve.
By this current of air the grain is dried.
The refuse separated from the grain as the series of sieves travels is received on
the floor of the chamber and is impelled by the returning trays to a shute through
which it is discharged.
The grain is discharged through a shute at the opposite end of the chamber to
that at which the refuse is expelled.

page_text: Boxes are placed above the travelling trays to receive dust and other light
impurities separated from the grain by the current of air. The boxes are adjustable
vertically to or from the top of the chamber and by virtue of the adjustment and
the regulation of the current of air from the fan the said impurities are collected
in separate boxes according to their substance.
Instead of the grooved stone table above described for cleaning the grain, a
corrugated or fluted iron or steel plate may be employed, or a perforated tray may
be used acted upon above and below by an endless band of brushes. The arrange-
ment of a travelling series of sieves above described and the brushes working in
contact therewith, as also the air current, are applicable for sifting and separating
flour, meal and other pulverulent substances.
Dated this 20th day of February 1890
NICHOLAS WATTS,
Bristol Bank Buildings, Bristol, Agent.
COMPLETE SPECIFICATION.
Improved Method of and Apparatus for Drying, Oleansing, and
Sifting Grain, in part applicable to Sifting or Separating Flour,
Meal, and the like.
I, HENRY SMITH, of 5, Queens Place, Pulteney Road, Bath, in the County
of Somerset, 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 :—
This invention consists in an improved method of and machinery or apparatus for
cleansing grain-more especially wheat-and separating the same from seeds, dirt
and other refuse.
The invention is also, in part, applicable to sifting and purifying semolina and
middlings, commonly termed ground products.
Under one arrangement of carrying into effect that part of my invention which
relates to cleansing grain, the latter is delivered upon a slab or table of stone the
upper face of which is serrated or grooved. Over the table works a pair of
endless chains carrying strips of wood or bars of metal having serrated or grooved
faces.
At intervals in the band of serrated bars are brushes likewise carried by the
chains.
The table and band are inclined from the feeding end downwards and the grain
as it is swept along by the bars and brushes is freed from adhering dirt which is
crushed and detached by the teeth in the bars moving over those in the table, the
grain being between them. At intervals in the table are gratings or screens
the mesh of which is of a size which permits the passage of refuse of smaller girth
than grain.
Such refuse as is not thus got rid of is carried along with the grain into a chamber
in which travels, at a suitable inclination, an endless band of sieves arranged step-
wise and secured to a pair of chains working round toothed pulleys centred on
shafts at each end of the chamber. The sieves have a vibratory motion imparted
to them as they travel, and this motion is obtained either by causing the chains to
run on serrated longitudinal bars or over rollers, or by providing the chains with
rollers running on serrated bars, or by any similar or analogous provision. By the
vibration of the sieves the grain is further sifted and is discharged from the chamber
through an outlet situated at the end opposite to that at which it is fed from the
cleansing and dirt-crushing apparatus above described. The refuse, as well as any
undersized grain, which passes through the sieves, falls on to the back of the band
as it returns and thence to the bottom of the chamber where it is scraped up by the
returning band of sieves to an outlet whereat it is discharged. Each sieve in its
passage round the toothed pulleys opens and on again closing is brought into

page_text: forcible contact with the preceding sieve, thus dislodging any adhering grain or
refuse.
Above the band of sieves and in contact therewith is an endless band of brushes
travelling in the same direction. By this band of brushes the grain is assisted in
its passage along the sieves which latter are kept clean by the brushes.
Instead of
consisting of a single tray only, each sieve may have two trays one above the other
at a convenient distance apart and of a different mesh so that the apparatus may be
employed for grading.
Instead of a stone table as above described in connection with the cleansing and
dirt-crushing-apparatus, the stationary serrated surface for dirt crushing may be of
iron or steel.
In the Provisional Specification left with my application for Letters Patent to
this invention is described an arrangement in which, by means of a fan and assorting
boxes, light refuse expelled from the grain as it passes over the sieves is collected.
I have found this part of my invention to be attended with disadvantages and I
therefore prefer not to adopt it. In my said Provisional Specification it is set
forth that this invention relates also to drying grain and that this is effected by
means of an exhaust fan inducing a current of air through the sieves. While it is
true that the grain would be in part thus dried it would not be wholly so and I
desire to have it understood that it is only in this limited sense that drying is
incidentally effected under my invention and I make no claim in this respect.
Referring to the accompanying sheets of illustrative drawings,
Fig. 1 represents, partly in elevation and partly in section, one arrangement of
machinery or apparatus for carrying my invention into effect. a is a chamber in
which dirt adhering to or accompanying the grain is crushed and in which the grain
is freed from a proportion of such dirt and of seeds and other refuse.
In the chamber b, with which the chamber a communicates in any convenient
manner, the grain is further sifted as hereinafter described.
Fig. 2 represents a part end elevation of and part transverse section through the
chamber a.
Fig. 3 represents a part end elevation of and part section through the chamber b.
The bottom of the chamber a is serrated transversely and is fitted at intervals
with gratings e of perforated metal or the like, the mesh or apertures in such gratings
being of a size sufficient to pass seeds, dirt or like refuse of smaller size than grain
of given dimensions.
Upon a pair of endless chains & working round toothed pulleys e are bars of
iron or steel having one face serrated, as shown. At intervals are brushes g also
carried on the chains d. The grain to be treated is fed into the chamber at h and
is assisted by the brushes g in its passage to the opposite end of the chamber which
is inclined at a suitable angle. Before the incoming grain reaches the serrated floor
of the chamber a current of air is drawn through it by means of an exhaust fan.
By this current of air a proportion of light refuse is sucked out from among
the grain.
A current of air applied in this way across the feed is an ordinary expedient
when feeding grain into sorting or sifting chambers. The serrated bars are
arranged to travel at a sufficient distance above the bottom of the chamber as to
avoid crushing the grain, but any refuse larger than the grain is squeezed between
the bars and the serrated bottom of the chamber and is reduced by the crushing
action. The said distance may be adjusted by causing the chains to run on guide
bars fixed to and extending along each side of the chamber. The under face of the
top of the chamber a may be serrated and the bars f be made to approach it so that
a dirt-crushing effect may be obtained both above and below.
f
A proportion of the crushed dirt, seeds and other refuse passes out through the
gratings and is collected in sacks placed thereunder, or in a bin or other receptacle.
The grain accompanied by such refuse as still remains mixed with it is delivered at i
into the chamber b and is received upon the endless band of sieves m carried upon
the chains n working round the toothed pulleys o centred on the shafts p.

page_text: These sieves, which are shown at an enlarged scale at Fig. 4, are composed of
trays of perforated sheet metal bound at each end by strips m.
The sieves which are fixed at one end to the chains are free at the other and the
free end of each overlaps the fixed end of the one in advance, making a step-wise
arrangement, as shown.
The sieves are caused to vibrate in their travel by the provision of serrated
bars y fixed to each side of the chamber b, on the serrations of which bars q run
rollers r carried on the chains n.
Vibration of the sieves may, however, be otherwise effected as, for instance, by
permitting the chains n to run on the bars without the intervention of rollers.
The grain as it passes down the band of sieves is thereby further sifted and is
discharged through the grain outlet s. The out-flowing grain is traversed, as is
usual, by a current of air induced upwards through the grain outlet s to the exhaust
nozzle which is connected to an exhaust fan. Accordingly, light refuse is by the
current of air blown out from among the grain and sucked away through the
nozzle v. The refuse and any undersized grain which passes through the perfora-
tions in the sieves falls on to the back of the band as it returns and thence to the
bottom of the chamber where it is scraped up to the refuse outlet t whereat it is
discharged. Each sieve in its passage round the toothed pulleys o has its free end
raised and becomes approximately tangential to the periphery of the pulley, as seen
at Fig. 1. When, after passing round the pulley, the sieve is free to resume its
normal position it is by the tension on the chains closed with a considerable amount
of force and thereby any grain or refuse jammed in the perforations or otherwise
adhering to the trays is dislodged. Above the band of sieves m is an endless band
of brushes u working round toothed pulleys u¹. By this band of brushes the grain
is assisted in its passage along the band of sieves and the sieves are kept clean.
Ground products such as semolina and middlings may be sifted and freed from
refuse by the band of sieves in the chamber band in this case sieves of a suitable
mesh for dealing with such substance must be substituted. When dealing with such
ground products the outlet s is partially closed by the door s¹ and air is admitted to
the chamber through inlets wat each side which inlets are closed when the whole
grain is passing through the chamber. A current of air applied in this way is a
common expedient. Instead of consisting of a single tray only, each sieve may be
composed of two trays T, T' of different sized mesh arranged as shewn at an
enlarged scale at Fig. 5.
This form of sieve is in itself not novel.
When such compound sieves are employed in connection with my invention the
assorted grain on arrival at the outlet is prevented from becoming again mixed
through the intervention of a partition which directs the discharge of the separated
grain into different receptacles.
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. Cleansing and sifting grain and separating it from dirt and other refuse by
passing the grain and refuse over a serrated or grooved surface (having sieves or
gratings at intervals) inclined at a suitable angle and by arranging an endless band
of serrated bars (with or without brushes at intervals) to travel over the said
serrated or grooved surface, the grain travelling between such surface and the
serrated faces of the endless band of bars, the intervening space being regulated so
as to prevent injury to the grain, substantially as hereinbefore described.
2. Cleansing and sifting grain and separating it from dirt and other refuse by
delivering the grain and refuse on to an endless travelling band of vibrating sieves
such as m, being perforated trays, fixed at one end to chains such as n, the other
end being free and overlapping the fixed end of the adjacent sieve, substantially a
described.
3. The provision, in connection with an endless travelling band of grain-sifting

page_text: shutter sieves such as m, of serrated or notched bars such as q, or the equivalent
thereof, as a path at each side for the pitch chains carrying the sieves, substantially
as hereinbefore described with reference to the accompanying drawings.
Dated this 16th day of December 1890.
NICHOLAS WATTS,
Bristol Bank Buildings, Bristol, Agent.