IMPROVEMENTS IN CENTRIFUGAL DRYING MACHINES OR EXTRACTORS
Year: 1876

page_text: LETTERS PATENT to Edward Griffith Brewer, of Chancery Lane, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN CENTRIFUGAL
DRYING MACHINES OR EXTRACTORS." A communication from abroad by
Messrs. Boulieu Brothers, and Charlon, of Lyons, France.
Scaled the 18th May 1877, and dated the 23rd November 1876.
PROVISIONAL SPECIFICATION left by the said Edward Griffith Brewer at
the Office of the Commissioners of Patents on the 23rd November 1876.
EDWARD GRIFFITH Brewer, of Chancery Lane, in the County of Middlesex.
'IMPROVEMENTS IN CENTRIFUGAL DRYING MACHINES OR EXTRACTORS." A com-
munication from abroad by Messrs. Boulieu, Brothers, and Charlon, of Lyons,
France.
The object of the apparatus forming the subject matter of this Invention is
intended to be used instead of extractors or centrifugal machines used in the
manufacture of sugar, potato flour, or meal, paper pulp, starch, chemical products
for drying grain, rice, coal, and generally for separating liquid from solids mixed
therewith.
This apparatus possesses great advantages over and above those which it is
intended to replace.
First. The yield is much greater because the layer to be dried is much smaller
although it is renewed continually.
Second. Partial and almost total suppression of hand work.
Third. The supply can be kept up without interruption by mechanical means and
the dried materials may even be mechanically raised.
A continuous centrifugal drying machine constructed according to this Invention
is composed of apparatus as follows:-
1. Of a cast-iron trough.
2. Of a drum made of sheet iron or copper fixed in such manner as to make
a tight joint.
3. Of a perforated calendar basket of conical shape, and made of copper or
iron, at bottom flat, and of cast metal, covered if necessary with a coating of

page_text: copper inside.
This basket is attached to a vertical shaft stepped in a socket
and carrying friction cone driven by friction pulley.
4. Of a drum in cast iron or other metal carrying one or several screw threads
or vanes made of iron or copper and truely fitting the basket. This
drum is held to its nave by cross pieces being cast in a piece with it and
of section. It is with it fixed to a hollow shaft made of cast, wrought iron, or
steel, concentric with the basket. This shaft carries a chambered toothed wheel
gearing into a toothed wheel keyed on an intermediate shaft on which is also keyed
another toothed wheel which gears with a toothed wheel on the friction cone.
5. Lastly, of a standard bracket firmly bolted to the trough for supporting a
horizontal shaft driven by strap, and transmitting its rotary motion to the parts
before mentioned. This shaft runs in lubricating bearings, the friction gear is
clutched in and out by spring lever and cam, the necessary lubrication for the
vertical shaft is provided from a grease box fitted to the upper collar bearing of said
shaft; there is also grease box to the intermediate shaft.
Operation of the machine.-Supposing the apparatus to be in motion and having
a given speed imparted to it which must be regulated and depend upon the quanity of
material to be treated, the drying is effected in the following manner-The material
is fed in into the screw drum continuously in any suitable manner by the upper
opening thereof, the centrifugal force throws it on to the conical sides fixed to the
drum, and turning with it the inclination of this side obliges it to descend to the
lower part on the bottom of the basket into a space there provided, from whence it
is sent back against the conical cleaner; then the screw, turning at a greater or lesser
speed than the basket, causes the material to ascend. During this ascent the time
occupied varies according to the material, the liquid part escapes by the perforated
sides and enters an annular space, from whence it is withdrawn by a pipe going
through the trough. Having arrived at the upper part of the basket the material
sufficiently dried meets with no further resistance, is thrown against the inside of
the trough where it falls to the bottom, from whence it is withdrawn by openings
formed for the purpose at the side and either by hand or mechanically.
The different speeds of the screw and the basket are obtained by the differential
gearings.
All the improvements consist in the particular form of the basket, and this form
is intended to suppress as much as possible the resistance due to friction of the
material during the ascent on the perforated cleaner of the basket and on the threads
of the screws.
These resistances are considerable. In all cases it results from the
form of the basket that the circumferential speed of the material increases in
proportion as it is dried, and consequently the liquid element is more difficult to
extract.
It should be noticed that a perforated envelope may be fitted round the basket
and the space thus obtained be provided with animal charcoal or other suitable
material for clarifying or filtering the sirups or liquids extracted by the apparatus.
The application of the motive power may be applied directly to the apparatus, the
steam cylinder in such case being fixed to the trough, the cross head guides to the
frame brackets and through connecting rod and crank to work the upper horizontal
shaft; other driving arrangements may also be employed besides the wheel and
friction cone, for examples, ordinary bevel toothed gearing; also the mechanical
movements instead of being placed at the top of the trough may be placed at the
bottom with the view of more easily cleaning the apparatus. The arrangements in
connection with the drum and screw are such that the latter may be raised and be
placed between the bracket and the trough in such manner as to have a suflicient
space provided for changing the animal charcoal or for cleaning the apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Griffith Brewer in the Great Seal Patent Office on the
23rd May 1877.
EDWARD GRIFFITH BREWER, of Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN CENTRIFUGAL DRYING MACHINES OR EXTRACTORS." A. com-
munication from abroad by Messrs. Boulieu, Brothers, and Charlon, of Lyons,
France,
The object of the apparatus forming the subject matter of this Invention is
intended to be used instead of extractors or centrifugal machines used in the
manufacture of sugar, potato flour, or meal, paper pulp, starch, chemical products
for drying grain, rice, coal, and generally for separating liquids from solids mixed
therewith.
This apparatus possesses great advantages over and above those which it is
intended to replace.
First. The yield is much greater because the layer to be dried is much smaller
although it is renewed continually.
Second. Partial and almost total suppression of hand work.
Third. The supply can be kept up without interruption by mechanical means and
the dried materials may even be mechanically raised.
As will be seen by the accompanying Drawing in which is represented an illus-
tration of an extractor constructed according to this Invention on a continuous
centrifugal drying machine the apparatus is composed :-
1°. Of a cast-iron trough M carrying the pan.
:-
2°. Of a drum P made of sheet iron or copper fixed in such manner as to make a
tight joint to a flange formed on the bottom and all round the circumference of tho
trough.
3°. Of a perforated calender basket Q of conical shape and made of copper or iron,
at bottom flat, and of cast metal, covered if necessary with a coating of copper inside.
This basket is attached to the vertical shaft R, stepped in the socket O and carrying
the friction cone S driven by the friction pulley T.
4°. Of a drum u in cast iron or other metal carrying one or several screw threads
or vanes made of iron or copper and truely fitting the basket. This drum is held to
its nave by cross pieces, being cast in a piece with it and of the form shewn in the
section G, H, Figure 3. It is with it fixed to the hollow shaft V made of cast,
wrought iron, or steel, concentric with the shaft R. This shaft carries the chambered
toothed wheel 6 keyed on the intermediate shaft X, on which is also keyed the
toothed wheel c which gears with a toothed wheel on S.
5°. Lastly, of a standard bracket Y firmly bolted to the trough M for supporting
the horizontal shaft Z driven by strap and transmitting its rotary motion to the
parts before mentioned. This bracket also carries the lubricating bearings & and d
of shaft Z, the friction gear is clutched in and out by spring lever and cam e, f,
and g, the necessary lubrication for the vertical shaft R is provided from the
grease box i to the upper collar bearing of the said shaft R; there is also grease
box to the intermediate shaft X.
Operation of the machine.-Supposing the apparatus to be in motion and having
a given speed imparted to it which must be regulated and depend upon the quantity
of material to be treated, the drying is effected in the following manner:-The
material is fed in into the screw drum continuously in any suitable manner by
the upper opening thereof, the centrifugal force throws it on to the conical sides j
fixed to the drum, and turning with it; the inclination of this side obliges it to
descend to the lower part on the bottom of the basket into the space k, from
whence it is sent back against the conical cleaner; then the screw, turning at a
greater or lesser speed than the basket, causes the material to ascend. During this
ascent the time occupied varies according to the material, the liquid part escapes by

page_text: A B, I cosa f= A B. P sin a,

page_text: Practically this result is impossible to realise, but it can be more or less approached,
thus making a = 20°, and taking the given precedents the resistance
P. cos af 38200 × 0.93969 x 0.50 ( ) 17948.
On the other hand
the power P sin a = 38200 x 034202 = 13065.
-
=
The difference 17948. 13005 = 4883 kos. is the friction which it is necessary
to overcome to produce the ascent. The mean ascending speed being always 0.005625.
The work absorbed by this friction will be 4883 × 0.005625 25 45 kilogram-
metres instead of 107.4. The friction of the material on the screw will be
4883 x 0.50 x 0.032 = 78.13 ktres. instead of 305-60. The total work then is
25457813=103.58 kilogrammetres instead of 413, which makes a force
sufficient to resist those frictions about four times less than with the cylindrical
basket.
We can still arrive much nearer in order to reduce these 103 kilogs. to 20 or 25.
In certain cases even it happens that the power is greater than the resistance that
takes place when tga will be greater than the coefficient of the friction ; then the
threads of the screw will cause a resistance and will moderate the ascent, which
would be too rapid without that.
In practice the coefficient of the friction varies in proportion as the material is
dried, whereby the resistance is the same or very nearly so. At all the points of the
height of the basket it is necessary that the angle a or inclination varies equally.
The result is arrived at by the following means-In making experiments the
coefficients of friction of the material have been found at the commencement of the
operation, at a quarter of the drying, at the middle of the operation, at three quarters
of same, and at the end, which has enabled the angles a, a¹, all, all, a¹¹, to be
found at the points a, b, c, d, f, corresponding to these coefficients (Fig. 6). In
uniting all these points the curve required is obtained tangent to the lines
a, a, b, b, c, c, d, d', f, f. It has been remarked that this curve approaches an arc
of a circle described from a central point o situate below the horizontal plan passing
by a.
When the materials and the coefficients of friction do not sensibly change the cone
is made regular, and A, B, is made straight (Figure 5).
Lastly it should be stated that the concave curve C, D, Fig. S, is obtained,
which will be the arc of a circle described from O situate above g; this will be when
the coefficients of friction diminish as the material becomes dried, a then becomes
diminished in proportion.
In all cases it results from the form of the basket that the circumferential speed
of the material increases in proportion as it is dried, and consequently the liquid
element is more difficult to extract.
It should be noticed that a perforated envelope may be fitted round the basket
and the space thus obtained be provided with animal charcoal or other suitablo
material for clarifying or filtering the syrups or liquids extracted by the apparatus.
The motive power may be applied directly to the apparatus, the steam cylinder in
such case being fixed to the trough M, the cross head guides to the frame bracket
and through connecting rod and crank to work the upper horizontal shaft. Other
driving arrangements may also be employed besides the wheel and friction conc, for
example, ordinary bevil toothed gearing. Also the mechanical movements instead
of being placed at the top of the trough may be placed at the bottom with the view
of more easily cleaning the apparatus.
The arrangements in connection with the drum and screw are such that the latter
may be raised and be placed between the bracket and the trough in such manner as
to have a suflicient space provided for changing the animal charcoal or for cleaning
the apparatus.
And having thus described and ascertained the nature of this Invention, I declaro
that I claim as the herein-before set forth improvements,―
Firstly. The employment of a conical basket with straight, or concave, or convex

page_text: side, according to the nature of the material to be extracted, in combination with a
screw worked by differential motion, as set forth.
And, Secondly. The arrangement and combination of parts, substantially as set
forth.
In witness whereof, I, the said Edward Griffith Brewer, have hereunto set
my hand and seal, this Nineteenth day of May, in the year of our Lord
One thousand eight hundred and seventy-seven.
E. G. BREWER. (L.S.)