Improvements in Purifiers for Middlings and the like.
Year: 1889

page_text: Date of Application, 7th. Dec., 1839
Complete Specification Left, 8h Sept., 189)-Accepted, 11th Oct., 1890
PROVISIONAL SPECIFICATION.
Improvements in Purifiers for Middlings and the like.
I, ANTHONY STEVENSON, of Seller Street Works, Chester, in the County of Chester,
Mill Wright, do hereby declare the nature of this invention to be as follows:-
This invention has for its object an improved method of and apparatus for purifying
middlings and the like from dust, bran, etc.
In place of the ordinary V troughs which have hitherto either been attached
rigidly to the framework of the machine or else to a framework above the sieve but
shaking with it I build up my sieve-frame in the form of V troughs with flat apexes
and attach the sieving material direct to the flat apexes of the ✓ troughs. The
V troughs thus would have precisely the same slope as the sieve but in some instances
to avoid this I give then a greater slope by forming them at one end with a cross-
section in the shape of a Y, and at the other end in the shape only of a V with the
apex truncated a little so as to form a flat surface for the sieve cloth to be fastened
to. To give a further fall too, to the troughs I may partially fill them up with a
board gradually coming to a point at the lower end. This board is so shapel that it
fills the V. trough nearly to its top at the upper end, but gradually runs away to a
point at the lower end. In this way a much greater slope is given to the working
bottom of the V trough than would otherwise be practicable and the V trough has the
largest capacity where it has the most material to carry.
.
I also find with ordinary middlings purifying that the amount of moisture in the
air and the temperature thereof have a very material effect on the middlings. In
order to gain the best effects I prefer to bring the air used for aspirating from the
outside of the building through a heating or drying apparatus by which it is dried or
heated or both before entering the machine. Furthermore instead of or in addition
to the ordinary aspirating apparatus I fix to the machine one or more travelling blast
pipes having exceedingly narrow orifices extending the whole width of the sieve and
immediately below it. These travelling orifices are so constructed and supplied with
mechanism as to be continuously or intermittently travelling up and down the sieve
just as travelling brushes have previously been made to do so that every point in
the under surface of the sieve at short intervals shall be attacked by this narrow blast
of air.
WM. P. THOMPSON & Co.,
Of, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Purifiers for Middlings and the like.
1, ANTHONY STEVENSON of Seller Street Works, Chester, in the County of Chester,
Mill Wright, 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 machines for purifying middlings
and the like from dust, bran, etcetera, the object of such improvements being to obtain
a better and more rapid separation of the impurities and to afford facilities for
collecting the same and for keeping the meshes of the sieve fabric clear.
The invention may be understood from the following description, reference being
had to the accompanying drawings, in which :-
Figure 1 is a transverse section of a middlings purifier furnished with my
improvements

page_text: igure is a long
dial section of the same.
Figure 3 is an elevation of the head end of the machine.
Figures 4 and 5 are transverse sections of the machine showing modifications
hereinafter described.
A is the framework of the machine and B the ordinary vibrating sieve thereof.
Instead of employing a series of V-shaped dust collecting troughs attached as hitherto
either rigidly to the machine framework A above the sieve or to a separate framework
above the sieve and shaking with it, 1 build up my sieve frame in the form of a
series of V-shaped troughs C with flat apices and attach the sieve-cloth B direct to
said flat apices.
In such an arrangement, the interior of the V-troughs would have exactly the
same slope longitudinally as the sieve, but in some instances, in order to obviate this
and give them a greater slope than the sieve-for the purpose of facilitating the
discharge of the matter deposited therein-1 form them at the head end with a
Y-shaped cross-section and at the tail end in the shape of a V with the apex truncated
a little, as aforesaid, the sieve cloth resting against or being fastened to the bottoms
of the troughs as before described. The fall of the troughs may be still further
increased by flooring each of them with a flat board (which nearly fills the trough
at its head end and gradually tapers away to a point at the tail end. Thus a much
greater fall can be given to the working bottoms of the V-shaped troughs than would
otherwise be practicable, and the troughs have the greatest capacity where they 'have
the most material to carry.
The troughs and sieve cloth are suspended, as is usual with sieve frames, by rods D,
and vibrated by eccentrics D' and rods D². The material from the troughs is dis-
charged into the shute E and the tailings from the sieve into a shute F.
The troughs may be formed of any suitable material, such as a wood, sheet metal,
pasteboard, canvas, calico, linen or other textile fabric. When formed of a textile
fabric, they are constructed as shown in Figure 4, the textile sides of the troughs
being fastened at their lower edges to a series of parallel bars (, to which the sieve
cloth is attached, and suspended at their upper edges from cords or chains C. The
two sides adjacent to the machine framework A are secured thereto as at C³.
Instead of, or in addition to, the ordinary aspirating apparatus, I provide the
machine with one or more travelling blast pipes G arranged either longitudinally or
transversely to the sieve and supplied with air by a fan H through a trunk J having
a flexible connection J¹. The pipes G have very narrow blast orifices g extending
the whole length (or width) of the sieve and immediately below it. The blast pipes
are caused to travel with a continuous or intermittent motion to and fro across (or
along) the sieve by means of any suitable mechanism, so that every point in the
surface of the sieve and the material passing over the same shall, at short intervals,
be subjected to a fine blast of air, and the meshes of the sieve are thus kept clear, and
the material more thoroughly and rapidly purified. In the construction shown in the
drawings, the pipes are secured to cross rails K, which are mounted upon rollers K'
capable of vertical adjustment as shown at K². Motion is imparted simultaneously
to the cross rails by the links K³, arms K' carried by shaft K³, link K, crank disc K
and worm gearing K8, the latter being driven by a chain and chain wheels K K
from the axle L of the feed roll.
The sieve brushes M may be attached to the upper sides of the last pipes, as shown,
so as to travel to and fro with them. Or the brushes may be placed transversely to
the sieve between it and the blast pipes and be caused to travel longitudinally thereto
by any suitable mechanism, such as that shown in Figure 5. Here the brushes are
attached to endless travelling chains, which pass over sprocket wheels M² placed in
any convenient position on the blast pipes G or air trunk J. The brushes thus
partake also of the transverse movement of the pipes G. The endless chains may be
driven in any suitable manner.
I also find that with ordinary middlings purifying, the amount of moisture in the
air and the temperature thereof have a very material effect on the middlings. In
order to gain the best effects, I prefer to bring the air used for aspirating and blast

page_text: from the outside of the building through a heating or drying apparatus by which it is
dried or heated or both before entering the machine. Many kinds of apparatus may
be employed for this purpose, such as a chamber provided with heating pipes, into
which chamber the air-preferably from the outside of the building-is admitted and
from which it is led in its dry or heated state to the fan of the purifier. The air may
also be purified before use by being drawn through canvas or other pervious fabric.
To this end the sides of the chamber may be clothed with fabric and the air drawn
into the chamber through said pervious sides.
When constructing a purifier with a blast apparatus such as above described, I am
enabled, by the slight addition of a cross spout at the tail ends of the blast pipes G,
to direct a blast of air on to the tailings, as they fall from the sieve down the shute F
for the purpose of removing a portion of the lighter matter therefrom. The jet orifice
of this cross blast spout may be made adjustable in any convenient manner.
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. In a purifier for middlings or the like, the combination of a vibrating sieve and
a series of very fine air jets directed against the under surface of the sieve and moving
to and fro across or along the same, substantially as described.
2. In a middlings purifier or the like, the combination of a vibrating sieve frame,
formed of a parallel series of V-shaped collecting troughs and of a sieve cloth attached
to or resting against the under sides thereof, substantially as described.
3. In a middlings purifier or the like, the combination with a blast apparatus such
as described in claim 1, of means for filtering heating or drying the air supplied
thereto, substantially as and for the purpose described.
"
Dated this 6th day of September 1890.
W.M. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.