Improvements in Purifiers Employed in Milling.
Year: 1889

page_text: Date of Application, 22nd Jan., 1889
Complete Specification Left, 22nd Oct.. 1889-Accepted, 18th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in Purifiers Employed in Milling.
I, HENRY JAMESON DAVIS of 82 Mark Lane, London, E.C., Milling Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention has for its object improvements in purifiers employed in milling.
In order to separate dust from middlings, semolina and like products, purifiers are
at present employed consisting of sioves through which air is caused to pass whilst
the product travels along the surface of the sieve. The air then conveys away the
dust. Now the object of my invention is to obtain a more uniform current through
every part of the surface of the siove also to intensify the air current immediately
after it leaves the surface of the sieve so that it may carry away effectually and
with certainty any particles lifted by the blast and also to provide a collecting surface
upon which these particles may be conveniently deposited.
For these purposes I provide immediately above the surface of the sieve a cover
made up of inclines arranged in ridge and furrow and at or near the summit of
every ridge I arrange a narrow slit or opening so that the air ascending through
the sieve is not checked by coming against horizontal surfaces but is led up between
converging inclines to the apertures in such manner that the air acquires a constantly
increasing velocity until it passes out. The inclined surfaces may be continuous
from end to end of the cover or they may be broken up into a series of pyramids
each with an aperture at or near the summit. The apertures are preferably lateral.
After passing through the apertures the air currents rapidly lose velocity and
the dust is then deposited upon the upper face of the cover between the inclined
surfaces or preferably upon a sheet placed to receive it; through this sheet the
inclines project. I employ brushes to sweep the dust along the receiving surface
and deliver it at the end of the cover into a suitable receptacle. Or the receiving
surface may have a shaking motion imparted to it which will cause the dust to be
delivered without the aid of a brush."
Dated this 22nd day of January 1889.
CARPMAEL & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in Purifiers Employed in Milling.
I, HENRY JAMESON DAVIS of 82 Mark Lane, London E.C. 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 has for its object improvements in purifiers employed in milling.
In order to separato dust or impurities from middlings, semolina and like
products, purifiers are at present employed consisting of sieves through which air
is caused to pass whilst the product travels along the surface of the sieve. The
air then conveys away the dust or impurities. Now the object of my invention
is to obtain a more uniform current through every part of the surface of the
sieve also to intensify the air current immediately after it leaves the surface of the
sieve so that it may carry away effectually and with certainty any particles lifted by
the blast and also to provide a more efficient collecting surface upon which these
particles may be conveniently deposited.
For these purposes I provide immediately above the surface of the sieve a cover
made up of inclines arranged in ridge and furrow and at or near the summit of every

page_text: ridge I arrange a narrow lateral slit or opening so that the air ascending through the
sieve is not checked by coming against horizontal surfaces but is led up between
converging inclines to the apertures in such manner that the air acquires a constantly
increasing velocity until it passes out. After passing through the apertures-the air
currents rapidly lose velocity and the dust or impurities are then deposited_npon the
upper face of the cover in the furrows or troughs between the ridges. I employ
brushes to sweep the dust along the receiving surface and deliver it into a suitable
receptacle.
In order that my said Invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS
Figure 1 is a longitudinal section of tho sieve and other parts of a purifier to which
my Invention is applied.
cc is a
Figure 2 is a transverse section of the same. a is the frame and a¹ is the silk surface
of the sieve. This sieve is mounted in the usual manner in a cnsing b.
stationary cover placed over the sieve; it consists of prisms of wood c¹ fixed in a
frame parallel the one to the other with their apices downwards.
Plates of sheet metal care fixed upon the prisms c¹ on either side and a
narrow lateral slit or aperture is left between the upper edges of each pair of
plates.
The sieve serves to separate the casing into two chambers an upper and a lower.
Air is drawn out by a fan from the upper chamber and this causes air to flow upwards
from the lower chamber through the silk surface of the siove. The semolina or the
like is fed on at the upper end of the sieve. The sieve receives a jogging movement
and the material becomes distributed over it with approximate uniformity; it travels
gradually down towards the lower end of the sieve whore the larger particles are
discharged whilst the smaller (with the exception of the dust or impurities) fall
through the sieve into the lower chamber and are collectod. The dust or impurities
are carried upwards by the current of air passing through the sieve and are so
separated.
Now this separation of the dust or impurities is effected by my invention more
perfectly than heretofore because I avoid all check to the air currents after passing
through the sieve and accelerate then continually until they pass by the orifices to
the upper surface of the cover so that a particle, which has once been lifted from the
surface of the sieve is certainly carried up above the receiving surface on which it is
ultimately deposited.
The bases of the prismns form the receiving surface for the dust or impurities which
are deposited upon this surface in the furrows or troughs between the plates c² c³ in
consequence of the air currents rapidly losing velocity when they enter the free
space over the cover c. d is a brush carried by endless bands passing around rollers
mounted within the casing; these rollers have a slow rotary motion imparted to them.
The dust is swept by the brush d along the top of the cover and is delivered into a
trough e. The trough e is mounted upon the sieve and partakes of the jogging
movement; this enables the trough to deliver the dust at the end of the sieve into a
suitable receptacle.
The lateral arrangement of the orifices in the cover presents several advantages;
the particles passing out by them are carried at once over the furrows which are to
receive them and they cannot fall back through the orifices when disturbed by the
brush or otherwise; and the brush whilst it cannot penetrate into the orifices serves
very efficiently to clear the troughs or furrows between them.
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. My improvement in purifiers consisting in providing above the surface of the

page_text: sieve, a cover entirely made up of inclines or converging surfaces which lead the air
currents rising from the sieve without check and with constantly increasing velocity
to the upper surface of the cover where a deposing surface is provided as herein
set forth.
2. The combination substantially as described consisting of the sieve; the cover
formed in ridge and furrow and with lateral apertures at the top of the ridges; and
the travelling brush serving to deliver the dust or impurities from the receiving
surface into a receptacle.
3. Apparatus substantially as represented by the annexed drawings.
H. JAMESON DAVIS.