IMPROVEMENTS IN CENTRIFUGAL DRYING MACHINES
Year: 1878

page_text: LETTERS PATENT to John Stevenson, of Barrow Collieries, near Barnsley, in
the County of York, for the Invention of "IMPROVEMENTS IN CENTRIFUGAL
DRYING MACHINES."
Scaled the 10th December 1878, and dated the 2nd July 1878.
PROVISIONAL SPECIFICATION left by the said John Stevenson at the Office
of the Commissioners of Patents on the 2nd July 1878.
JOHN STEVENSON, of Barrow Collieries, near Barnsley, in the County of York.
"IMPROVEMENTS IN CENTRIFUGAL DRYING MACHINES."
This Invention has for its object improvements in centrifugal drying machines,
and consists in so constructing a centrifugal drying machine (or hydro-extractor)
that the machine or apparatus can be filled and emptied without any stoppage
taking place. The filling can be done as quickly as required, the emptying being
effected in a few seconds.
According to one mode of carrying out this Invention the machine is constructed
of a main shaft, placed either horizontally or vertically, according to the nature of
the material to be dried. Upon this shaft is keyed a circular plate or cheek, to
which a cast-iron ring is rivetted by means of distance pins, leaving a space between
the check and the ring, to allow the dried substance to pass between the two. To
the ring is secured a frustrum of a cone constructed of perforated iron, or of any
other material which may be thought suitable, and at such an angle that the
material introduced into it whilst in motion is forced towards the base of the cone
by the action of the centrifugal force against the inner surface of the cone.
The cone is kept closed by a circular plate fitting within it and sliding upon the
shaft, revolving at the same time. The plate is moved and secured where wanted
by a mechanical arrangement designed for the purpose and partly rotating with the
plate. The whole is enclosed in a casing constructed of any material suitable for
the purpose, but so arranged that the water or liquid extracted from the substanco
put into the machine is kept entirely separate from the dried material.
Centrifugal machines constructed according to this Invention are adapted for
drying any substances for trade or manufacturing purposes speedily.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Stevenson in the Great Seal Patent Office on the 2nd January
1879.
JOHN STEVENSON, of Barrow Collieries, near Barnsley, in the County of York.
"IMPROVEMENTS IN CENTRIFUGAL DRYING MACHINES."
This Invention consists in constructing a centrifugal drying machine (or hydro-
extractor) in the manner herein-after described, to enable the machine or apparatus
to be filled and emptied without any stoppage taking place. The filling can be
done as quickly as required, the emptying being effected in a few seconds.
The machine is constructed of a niain shaft, placed either horizontally or vertically,
according to the nature of the material to be dried. Upon this shaft is keyed a
circular plate or check, to which a cast-iron ring is rivetted by means of distance
pins, leaving a space between the cheek. and the ring, to allow the dried substance
to pass between the two. To the ring is secured a frustrum of a cone constructed
of perforated iron, or of any other material which may be thought suitable, and at
such an angle that the material introduced into it whilst in motion is forced towards
the base of the cone by the action of the centrifugal force against the inner surfaco
of the cone,
The cone is kept closed by a circular plate fitting within it and sliding upon the
shaft, revolving at the same time. The plate is moved and secured where wanted
by a mechanical arrangement designed for the purpose and partly rotating with the
plate. The whole is enclosed in a casing constructed of any material suitable for
tho purpose, but so arranged that the water or liquid extracted from the substance
put into the machine is kept entirely separate from the dried material.
Centrifugal machines constructed according to this Invention are adapted for
drying any substances for trade or manufacturing purposes speedily.
In order that my Invention may be fully understood and readily carried into
effect, I have shown in the Drawings hereunto annexed a centrifugal drying machine
constructed according to my Invention.
Figure 1 is a vertical section of the machine; Figure 2 is a plan view, with the
upper part of the casing removed; and Figure 3 is an end view of the same.
A is the main shaft, upon which is keyed the disc or armed wheel B; to this a
ring C is rivetted by means of the distanco bars D, to enable any substance to pass
freely between them. To the ring C is secured a frustrum of a cone K, constructed
of any material which may be thought suitable for the substance to be dryed.
This mode of attaching or suspending the cone leaves the base perfectly free from
any obstruction. A small circular conical plate E is fixed round the outer base of
the cone, to prevent the escaping liquid from mixing with the dryed substance.
The circular door O closing the base of the conc slides freely on the shaft, and is
connected to the steam gear by means of the clutch and levers T, which partly
revolve with the machine.
The circular door O is closed and opened by means of the steam gear M, this
being worked by worms and wheels so arranged that the steam is turned into the
top or bottom of the small cylinder R by a cam worked by the worms and wheels
and a weighted lever P, and calculated to allow the machine to make a given
number of revolutions per minute to one revolution of the cam G, according to the
substance charged. The machine is enclosed in a strong casing W, constructed with
a ridge V dipping into the V of the cone, and separating the dryed substance from
the liquid.
The mode of working the machine is as follows:-The substance is charged
through the hopper S into the cone K whilst in motion, and slides by the rotary
force towards the base of the cone, the moisture escaping meanwhile. When the
machine has worked a given time the steam, by means of the cam G, is turned into
the top of the cylinder, which throws back the circular door O, thus allowing the
substance to escape instantly through the bars D into the compartment I, and falls

page_text: into a hopper or other receptacle at the bottom. The liquid escaping through the
perforated cone is conveyed away through the opening L. The door is again closed
immediately by the steam being turned into the bottom of the cylinder and the
same operation is repeated.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I am aware that it has before been
proposed to construct centrifugal drying machines in such a manner that they may
be filled and emptied without stopping the rotation of the machine, and also that it
has before been proposed to effect this object by making the revolving vessel of the
forin of a frustrum of a cone, open at both ends, and by making the vessel capable
of being slidden endwise along its shaft, so that its base may either be moved up
to a disc which is fast on the shaft and be so closed or be moved away from it, and
so opened to allow the vessel to empty. What I claim is,―
First. The combined arrangement of centrifugal drying machine with automatic
opening and closing of the end door of the revolving conical vessel, substantially
as herein-before described.
Second. The combination of the cone carried by a ring that is secured by distance
bars to a disc or wheel fast on the main shaft (so leaving the cone perfectly clear
for the free passage of dryed substance), together with the moveable door capable
of being slidden endwise along the shaft, to open and close the base of the conical
vessel, substantially as berein-before described.
In witness whereof, I, the said John Stevenson, have hereunto set my hand
and seal, this First day of January, in the year of our Lord One thousand