Granular, or Semiliquid Materials.
Year: 1885

page_text: Granular, or Semiliquid Materials.
We, JOHN FYFE STEWART, of N° 26 Mark Lane in the City of London, Engineer,
and THOMAS SPENCER PAYNE, of N° 21 Denmark Road, Croydon in the County
of Surrey, Carpenter do hereby declare the nature of the said invention for
IMPROVED APPARATUS .FOR SIFTING GRADING OR SORTING PULVERULENT,
GRANULAR OR SEMI LIQUID MATERIALS to be as follows:-
"
According to our invention we construct a screening or sifting surface of a
shallow dished, cup shaped or conical form, which is mounted upon a vertical
revolving shaft inside a closed casing, so that as the material to be sifted or sorted
is fed from a hopper centrally on to the sifting surface, it is caused by the
centrifugal force resulting from the more or less rapid revolution thereof to travel
over the sifting surface from the centre towards the outer periphery, during which
passage, the finer particles of the material will fall through the sieve into the
casing below, while the coarser particles that will not pass through the openings
of the sieve are thrown over the edge thereof into a circular receptacle or trough
surrounding the sieve, whence they are removed by means of rotating scrapers
attached to the periphery of the sieve, which deliver them into one or more shoots.
The part of the casing below the sieve into which the sifted material falls is, by
preference, made conical, or it may follow the configuration of the sieve, and, when
necessary, scrapers are fixed on the underside of the latter, which carry the sifted
material to one or more other shoots.
The sifter may have its surface made with holes or meshes of uniform size, or it
may be made with concentric bands of different degrees of fineness, so that as the
material passes from the centre to the periphery, the finest particles will first fall
through the central part of the sieve then slightly coarser particles will pass
through the next part of the sieve and so on, until only the very coarsest particles
are thrown over the edge. In this case, the bottom of the casing would be divided
into a corresponding number of concentric annular compartments for receiving the
material of different degrees of fineness.
Or according to another modification, there may be arranged two or more such
above described dished sifters one above the other, which may be of different
degrees of fineness, the uppermost one having apertures that will let all but the

page_text: very coarsest particles pass through, which are thrown over the edge into an
annular trough, while those below are of gradually increasing fineness.
.
The material is by preference delivered from the hopper on to a conical
distributor fixed to the sifter shaft, and having an annular opening through which
the material is delivered uniformly on to the centre of the sifter.
In order to keep the meshes or openings of the sifter clear, it may be subjected
to the rapidly succeeding blows of a vibrating knocker attached by a spring to the
casing and acted upon by tappets on the circumference of the sifter.
The above described sifting apparatus may be applied with advantage to the
sifting or sorting of pulverulent materials such as cement or flour, of granular
materials such as for grading wheat, or wheat products, and for semi liquid
materials such as "slurry" in cement works.

page_text: Granular, or Semiliquid Materials.
We, JOHN FYFE STEWART, of N° 26 Mark Lane in the City of London, Engineer,
and THOMAS SPENCER PAYNE, of N° 21 Denmark Road, Croydon in the County of
Surrey, Carpenter, 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 :-
According to our invention we construct a screening or sifting surface of a
shallow dished, cup shaped or conical form, which is mounted upon a vertical
revolving shaft inside a closed casing, so that as the material to be sifted or sorted
is fed from a hopper centrally on to the sifting surface, it is caused, by the centri-
fugal force resulting from the more or less rapid revolution thereof, to travel over
the surface from the centre towards the outer periphery, during which passage the
finer particles of the material will fall through the sieve into the casing below,
while the coarser particles that will not pass through the openings of the sieve are
thrown over the edge thereof into a circular receptacle or trough surrounding the
sieve, whence they are removed by means of rotating scrapers attached to the
periphery of the sieve, which deliver them into one or more shoots. The part of
the casing below the sieve into which the sifted material falls is, by preference,
made conical, or it may follow the configuration of the sieve, and, when necessary,
scrapers are fixed on the underside of the latter, which carry the sifted material to.
one or more other shoots.
The sifter may have its surface made with holes or meshes of uniform size, or it
may be made with concentric bands of different degrees of fineness, so that as the
material passes from the centre to the periphery, the finest particles will first fall
through the central part of the sieve, then slightly coarser particles will pass
through the next part of the sieve and so on, until only the very coarsest particles
are thrown over the edge. In this case the bottom of the casing would be divided
into a corresponding number of concentric annular compartments for receiving the
material of different degrees of fineness.
Or, according to another modification, there may be arranged two or more such
above described dished sifters, one above the other, which may be of different
degrees of fineness, the uppermost one having apertures that will let all but the
very coarsest particles pass through, which are thrown over the edge into an
annular trough, while those below are of gradually increasing fineness.
The material is, by preference, delivered from the hopper on to a conical
distributor fixed to the sifter shaft, and having an annular opening through which
the material is delivered uniformly on to the centre of the sifter.
In order to keep the meshes or openings of the sifter clear, it may be subjected
to the rapidly succeeding blows of a vibrating knocker, áttached by a spring to the
casing and acted upon by tappets on the circumference of the sifter.
The above described sifting apparatus may be applied with advantage to the
sifting or sorting of pulverulent materials such as cement or flour, of granular
materials, such as for grading wheat, or wheat products, and for semi-liquid
materials, such as slurry in cement works.

page_text: Fig. 1 of the accompanying drawing shews a vertical section of a sifting apparatus
constructed according to our above described invention, Fig. 2 shews a plan. A. is
the sieve, by preference of parabolic form, the sifting surface being made in segments,
attached to radial ribs that are secured to a central boss K fixed on the shaft L,
the outer ends of the ribs being fixed to a circular rim M. Beneath the sifter A
is a conical casing B provided with one or more discharge shoots D, and sur-
rounding the periphery of the sifter is the annular trough C, having one or more
discharge shoots E. To the shaft L is fixed a spreader G with annular opening,
and in the top of the casing is fixed the feed hopper F. The sifter receives rotary
motion through a pulley N and band.
The material to be treated being fed into the hopper, passes thence on to the
spreader, which distributes it uniformly over the sifting surface. The centrifugal
action of the sifter causes the material to travel radially in an outward and upward
direction over the sifting surface, the finer particles being thus made to pass
through the same, while the coarser particles are discharged over the rim M into
the trough C. To the rim M are fixed scrapers O that convey the material to the
shoot E as they rotate with the sifter, and on the underside of the sifter A are
fixed other scrapers P that convey the material passing through the sifter to the
shoot D.
Access is gained to the interior of the sifter through a door J and to the trough C
through the door II.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is-
1. The use for sifting, grading or sorting pulverulent, granular, or semi-liquid
materials, of a rotating sifter of a shallow dished, cup shaped or conical form, into
the centre of which the material to be treated is delivered, so that by the centri-
fugal action it is caused to travel outwards over the sifting surface, through which
the finer particles pass while the coarser particles are delivered over the outer edge
of the sifter into a circular collecting trough, substantially as herein described.
2. The combination of the revolving dished sifter A with scrapers O and P,
casing B with shoot D, circular trough C with shoot E and distributor G arranged
and operating substantially as herein described.
Dated this 3rd day of March 1886
ABEL & IMRAY,
Agents for the Applicants,