IMPROVEMENTS IN CONTINUOUS ACTING CENTRIFUGAL DRYING MACHINES
Year: 1884

page_text: I, EDWARD CHARLES ROETTGER of Brunswick in the Empire of Germany,
Civil Engineer do hereby declare the nature of my invention for IMPROVEMENTS
IN CONTINUOUS ACTING CENTRIFUGAL DRYING MACHINES to be as follows:-
f
My invention relates to centrifugal drying machines constructed and arranged
so that their action is continuous.
The improved centrifugal drying machine consists of a lenticular chamber formed
by two convex or curved metal caps or plates perforated with holes and covered
over by a cloth or filtering medium mounted upon a suitable rotatory shaft or
spindle so that both sides of the said chamber are convex and that the outer edges
or circumferences of the said caps or plates are opposite to each other and nearly
touch each other a small opening or slit being left between them for the purpose
of allowing the material which has been dried to escape from the said chamber.
In the upper metal cap of the lenticular chamber is formed round the shaft a
circular opening through which the materials to be dried are fed into the said
chamber.
The angle formed by the ends of the lenticular chamber may be more or less acute
and the caps or plates forming the said lenticular chambers instead of being both
convex and symmetrical may be one convex and the other concave, the concave
plate being of greater radius than the convex plate, or the said lenticular chamber
may be formed by corrugated plates or the under plate may be conical or funnel
shaped the upper plate being flat or nearly so-or both plates may be flat, leaving
between them a comparatively thin cylindrical space.
Instead of both of the caps or plates being perforated with holes, only one of
them may be so perforated.
The liquid which traverses the permeable sides of the lower cap or plate falls
into a trough or basin placed round the said lower cap or plate and passes off
therefrom through a suitable pipe or channel and the liquid traversing the permeable
sides of the upper cap or plate passes into a suitable circular gutter or channel
which communicates with the trough or basin round the under cap or plate and
the liquid passes out with that from the under cap or plate. Placed around the
whole apparatus is a cylindrical or other suitably shaped chest or case against
which the dried material strikes after passing out from the lenticular chamber
7

page_text: •
through the slit or opening between the two enclosing caps or plates, the said dried
material then falls upon an inclined plane or hopper and passes out of the said
enclosing chest or case when it may be removed in baskets or otherwise.
The enclosing chest or case may be made of perforated metal and covered with
cloth or other suitable filtering medium and when it is required that the dried
material which is projected from the lenticular chamber tangentially with a velocity
equal to that of the outer periphery of the said chamber should not be broken, the
inner surface of the enclosing chest or case may be covered with cloth, felt, sponges,
or other material which will deaden the shock.
The upper cap or plate is affixed to the under cap or plate by screws or bolts
and between the said upper and lower caps or plates are formed cross bars or
feathers which may be disposed radially or spirally and may be solid or hollow and
covered with cloth or other filtering medium or they may be perforated with holes
and in communication with the trough or channels outside the chamber bands of
India rubber or gutta-percha interposed between the surfaces, by their elasticity
allowing the caps or plates to be brought nearer to one another or to be kept further
apart, thus regulating the width of the slit or opening between the caps or plates
as required for it is obvious that upon the width of the said slit or opening and
upon the velocity of rotation of the lenticular chamber depends the time that each
particle of material will remain in the said chamber before escaping therefrom and
consequently the drying effect produced by the machine upon the material operated
upon.
The rotatory shaft carrying the caps or plates which form the lenticular chamber,
the frame of the machine and the driving gear are such as are usually used with
centrifugal drying machines of ordinary construction.
The shaft on which are mounted the caps or plates may be vertical or
horizontal.
The slit or opening for the discharge of the dried material may be situated either
above or below the centre line, of the lenticular chamber-or on the said centre
line as described.
The action of the machine is as follows:
The material to be dried, which may be sugar, starch, seeds, beetroot pulp,
potatoes, bruised malt from distilleries, slack coal, moist sand, clay or any other
semi-fluid substance, is fed into the lenticular chamber continuously through the
aperture in the top of the upper cap or plate by means of a suitable channel or
gutter and the liquid is driven off by centrifugal force through the permeable
surface of the upper and lower cap or plate and the solid parts of the material
escape through the slit or opening round the lenticular chamber.
In some cases it may be useful to heat by steam or otherwise the caps or plates
forming the lenticular chamber.
For the treatment of some substances, the slit or opening for the escape of the
dried material may be closed at the beginning of the operation by an elastic ring
or annular band of India rubber or of very elastic metal which will not open the
slit until the centrifugal force overcomes its elasticity or springs or weights pressing
upon the upper cap or plate may be used to close the said slit or aperture until
opened by the centrifugal force.

page_text: I EDWARD CHARLES ROETTGER, of Brunswick, in the Empire of Germany
Civil Engineer, do hereby declare the nature of my invention for IMPROVEMENTS
IN CONTINUOUS ACTING CENTRIFUGAL DRYING MACHINES and in what manner
the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
My invention relates to centrifugal drying machines constructed and arranged so
that their action is continuous.
The improved centrifugal drying machine consists of a lenticular chamber formed
by two convex or curved metal caps or plates perforated with holes and covered
over by a cloth or filtering medium mounted upon a suitable rotatory shaft or
spindle so that both sides of the said chamber are convex and that the outer edges
or circumferences of the said caps or plates are opposite each other and nearly
touch each other, a small opening or slit being left between them for the purpose
of allowing the material which has been dried to escape from the said chamber. In
the upper
metal cap of the lenticular chamber is formed round the shaft a circular
opening through which the materials to be dried are fed into the said chamber.
The angle formed by the ends of the lenticular chamber may be more or less
acute and the caps or plates forming the said lenticular chambers instead of being
both convex and symmetrical, may be one convex and the other concave, the
concave plate being of greater radius than the convex plate, or the said lenticular
chamber may be formed by corrugated plates, or the under plate may be conical
or funnel shaped, the upper plate being flat or nearly so-or both plates may be
flat, leaving between them a comparatively. thin cylindrical space,-Instead of both
of the caps or plates being perforated with holes, only one of them may be so
perforated.
The liquid which traverses the permeable sides of the lower cap or plate falls
into a trough or basin placed round the said lower cap or plate and passes off
therefrom through a suitable pipe or channel and the liquid traversing the
permeable sides of the upper cap or plate passes into a suitable circular gutter
or channel which communicates with the trough or basin round the under cap or
plate and the liquid passes out with that from the under cap. or plate. Placed
around the whole apparatus is a cylindrical or other suitably shaped chest or case
against which the dried material strikes after passing out from the lenticular
chamber through the slit or opening between the two enclosing caps or plates, the
said dried material then falls upon an inclined plane or hopper and passes out of
the said enclosing chest or case when it may be removed in baskets or otherwise..
The enclosing chest or case may be made of perforated metal..and, covered
with cloth or other suitable filtering medium and when it is required that the
dried material which is projected from the lenticular chamber tangentially with

page_text: a velocity equal to that of the outer periphery of the said chamber should not
be broken, the inner surface of the enclosing chest or case may be covered with
cloth, felt, sponges or other material which will deaden the shock.
The upper cap or plate is affixed to the under cap or plate by screws or bolts and
between the said upper and lower caps or plates are formed cross bars or feathers
which may be disposed radially or spirally and may be solid or hollow and covered
with cloth or other filtering medium or they may be perforated with holes and in
communication with the trough or channels, outside the chamber; bands of India-
rubber or gutta percha interposed between the surfaces, by their elasticity allowing
the caps or plates to be brought nearer to one another or to be kept further apart;
thus regulating the width of the slit or opening between the caps or plates as
required; for it is obvious that upon the width of the said slit or opening and upon
the velocity of rotation of the lenticular chamber depends the time that each
particle of material will remain in the said chamber before escaping therefrom, and
consequently the drying effect produced by the machine upon the material operated
upon.
The rotatory shaft carrying the caps or plates which form the lenticular chamber
the frame of the machine and the driving gear are such as are usually used with
centrifugal drying machines of ordinary construction.
The shaft on which are mounted the caps or plates may be vertical or horizontal.
The slit or opening for the discharge of the dried material may be situated either
above or below the centre line of the lenticular chamber or on the said centre line
as described.
The action of the machine is as follows:-
"
The material to be dried, which may be sugar, starch, seeds, beetroot, pulp,
potatoes, bruised malt from distilleries slack coal moist' sand, clay or any other
semi-fluid substance is fed into the lenticular chamber continuously through the
aperture in the top of the upper cap or plate by means of a suitable channel or
gutter and the liquid is driven off by centrifugal force through the permeable
surface of the upper and lower cap or plate and the solid parts of the material
escape through the slit or opening round the lenticular chamber. In some cases it
may be useful to heat by steam or otherwise the caps or plates forming the
lenticular chamber.
For tlie treatment of some substances the slit or opening for the escape of the
dried material may be closed at the beginning of the operation by an elastic ring
or annular band of India-rubber or of very elastic metal which will not open the
slit until the centrifugal force overcomes its elasticity-or springs or weights
pressing upon the upper cap or plate may be used to close the said slit or aperture
until opened by the centrifugal force:
The upper cup or plate of the lenticular chamber or receptacle may be constructed
and arranged so that during the rotation of the said chamber or receptacle it may
be raised from or lowered onto the lower cap or plate and its position in relation to
the said lower cap may be adjusted as required.
Having now described the nature of my invention, I will proceed to describe
with reference to the accompanying drawings, the manner in which the same is to
be performed.
Fig. 1 represents a sectional elevation of a continuous acting centrifugal drying
machine, constructed according to this invention. Fig. 2 is a plan view of the
same partly in section. Figs. 3. 4. 5. 6. and 7 are diagrams representing certain
modifications in the construction of the machine as hereinafter described.
The improved centrifugal drying machine consists of a lenticular chamber
or receptacle a formed by two convex of curved saucer shaped metal caps or
plates a³ and a perforated with holes and covered over by a cloth or filtering
medium, mounted upon a rotatory shaft or spindle h so that both sides of the said
chamber or receptacle a are convex and that the outer edges, or circumferences of
the said caps a³ and d are opposite each other and nearly touch each other, a smáll

page_text: opening or slit a being left between them for the purpose of allowing the material
which has been dried to escape from the said chamber or receptacle.
In the upper cap or plate a³ is formed round the shaft h a circular opening a¹
through which the materials to be dried are fed into the chamber or receptacle a.
The angle formed by the ends of the plates a³ and a* may be more or less acute
and the caps or plates forming the lenticular chamber or receptacle, instead of being
both convex and symmetrical as represented in Figure 1, may be one convex and
the other concave, the concave plate or cap being of greater radius than the convex
plate or cap, as indicated in the diagram Fig. 3 where a is the convex cap or plate
and as is the upper concave cap or plate or the under cap or plate a' may be
concave and the upper one a³ may be convex as indicated in the diagram Fig. 4-
Or the said lenticular chamber or vessel may be formed of corrugated plates as
indicated at a³, a in the diagram Fig. 5, or the lower plate or cap a may be conical
or funnel shaped; the upper plate a³ being flat or nearly so as indicated in the
diagram Fig. 6,–
-or both plates may be flat leaving between them a comparatively
thin cylindrical space.
Instead of both of the caps or plates a³, a' being perforated with holes, in some
cases only one of them may be so perforated.
The liquid which traverses the permeable sides of the lower cap or plate a* (Fig. 1)
falls into a trough or basin b placed round the said cap or plate a and passes off.
therefrom through the pipe or channel -and the liquid traversing the permeable
sides of the cap or plate a³ passes into the circular gutter or channel e which
communicates with the trough or basin b by means of the gutter or channel d
and the liquid passes out with that in the trough or basin 6 through the pipe or
channel d
Placed around the lenticular receptácle a is a cylindrical or other suitably shaped
chest or case e against which the dried material strikes after passing out from the.
lenticular chamber or receptacle through the slit or opening a². The said dried
material then falls upon an inclined plane or hopper f and passes out from the
machine when it may be removed in baskets or otherwise.
The enclosing chest or case e may be made of perforated metal and covered with
cloth or other suitable filtering medium and when it is required that the dried
material, which is projected from the lenticular chamber or receptacle a tangentially
with a velocity equal to that of the outer periphery of the receptacle a, should not
be broken, the inner surface of the chest or case e, may be covered with cloth, felt,
sponges or other substances which will deaden the shock.
The upper cap or plate a³ is affixed to the under cap or plate a' by screws or
bolts g¹ (figure 2) and between the said caps or plates a³ and a' are formed cross
bars or feathers g which may be disposed radially as shown in fig. 2 or spirally the
said cross bars or feathers g may be made solid or hollow and may be covered with
cloth or other filtering medium or they may be perforated with holes and ini
communication with the trough or basin 6 or the gutter c: bands of India-rubber
or gutta-percha interposed between the surfaces allowing by their elasticity the
caps or plates as and a to be brought nearer to one another or to be kept further
apart, thus regulating the width of the slit or opening a² as required, for it is
obvious that upon the width of the said slit or opening a2 and upon the velocity
of rotation of the chamber or receptacle a depends the time that each particle of
material will reinain in the said chamber or receptacle a before escaping therefrom
and consequently the drying effect produced by the machine upon the material
operated upon.
The rotatory shaft or spindle h with its pulley k and driving gear and the
frame of the machine are such as are usually used in centrifugal drying machines
of ordinary construction and need not be further described.
Instead of being mounted vertically as shown in fig. 1-the rotatory shaft or
spindle, may be mounted horizontally--and the slit or opening a instead of being

page_text: 6
on the centre line of the receptacle a as represented may be situated either above
or below the said centre line.
T The action of the machine is as follows:
The material to be dried which may be sugar, starch, seeds, beetroot pulp,
potatoes, bruised malt from distilleries, slack coal, moist sand, clay or any other
semi fluid substance, is fed into the lenticular chamber or receptacle a continuously
through the aperture a¹ by means of a suitable channel or hopper and rotatory
motion being given to the machine, the liquid is driven off by centrifugal force,
through the permeable surfaces of the caps or plates a³ and a¹ and the solid parts
of the material escape through the slit or opening a².
In some cases it may be useful to heat by steam or otherwise the parts a³.a.
For the treatment of some substances the slit or opening a² may be closed at the
beginning of the operation by means of an elastic ring or band of India-rubber or
of very elastic metal affixed to either of the plates or covers a³, a, as indicated
at m, m in the diagram Fig. 7 the said ring or band m, m being disposed so that it
will not uncover the slit or opening a³ until the centrifugal force overcomes its
elasticity or weights or springs n, n figures 6 and 7 pressing upon the upper cap
or plate a³ of the chamber or receptacle a may be used to close the slit or
opening a² until opened by centrifugal force, the upper cap or plate as being, in
such cases, arranged so as to be capable of rising and falling within certain limits.
Figures 8, 9 and 10 of the accompanying drawings illustrate a modification of
my'invention in which the upper cap or plate of the lenticular chamber or receptacle
may be constructed and arranged so that during the rotation of the said chamber
or receptacle it may be raised from or lowered onto the lower cap or plate and its
position in relation to the said lower cap may be adjusted as required.
Figure 8 is a vertical section and Fig. 9 a plan partly in section of a centrifugal
drying machine containing the said modification-Fig 10 is a vertical section of one
of my centrifugal drying machines mounted in position and illustrating another
mode of raising and lowering the upper cap or plate of the lenticular chamber or
receptacle.
In Figs 8 and 9 the bottom cap or plate a¹ made of cast metal is turned at its
outer edge x so as to be perfectly true. The said cap or plate a* is affixed upon
the shaft or spindle h which receives rotatory motion from the shaft through the
friction wheels k¹, k². The upper cap or plate a³ the edge y of which is also turned
true is made of cast metal and is formed with a neck a³ and a grated funnel or
receiver a through which the material to be dried is fed into the chamber or
receptacle a. The said cap, or plate a³ turns freely upon the extended upper
cylindrical end of the shaft h. Upon the upper end of the neck a bears a pointed
centre piece m which is by its upper end jointed to the lever n and is connected to
the neck a by a clutch o which embraces the shoulders m¹ of the centre piece m
and a of the neck a³ respectively.
n is a lever, one end of which is jointed at n¹ to a bracket n² upon the standard n³,
n is a standard affixed upon the bed-plate and to the upper end of which is
jointed the two armed lever n³, no the arm ne being terminated by a handle and
the arm n being formed at its upper end with a curved slide n' in which engages
a stud or pin n on the end of the lever n.
By means of the lever n the upper cap or plate a³ may be raised or lowered
during the rotation of the machine, the lever n³, n6 fixing the cap or plate a³ in the
required position,
The cap or plate may if preferred be raised or lowered during the rotation of
the machine by means of a weighted lever as represented in figure 10 in which n is
the weighted lever jointed at one end of the standard n¹ and resting by a pointed
centre piece m' upon the neck a³ of the upper cap or plate a³. Or the upper cap or
plate may be raised or lowered during the rotation of the machine by forming
screw threads upon the upper end of the shaft h and by forming within the neck a
a screw box capable of screwing upon the said screw-threads. By applying a brake

page_text: to the upper cap or plate a³ during the rotation of the machine, the velocity of the
rotation of the said cap or plate a³ will be reduced and the said cap or plate a³ will,
by the action of the screw box on the screwed parts of the shaft h screw itself up
the shaft h and the said upper cap or plate as will be raised from the lower cap or
plate at the screw-threads on the shaft should be left-handed and the chamber or
receptacle a should rotate in a contrary direction When the upper cap or plate a³
has reached the highest position which it is desired to attain, its upward motion is
arrested by an adjustable ring upon the shaft h. By then releasing the brake, the
cap or plate à³ will very soon acquire the same velocity as the under cap or plate a-
aud when it is required afterwards to close the chamber or receptacle a a brake is
applied to the under cap or plate a' when the screw box in the neck of the upper
cap or plate a³ will engage with the screw thread on the shaft h and bring down
the said cap or plate a³ upon the lower cap or plate a. By the modified arrange-
ment herein before described, the dried material in the chamber a may be removed
therefrom intermittently without completely stopping the rotation of the machine.
When treating such substances as sugar scum sucrate of lime, starch mixed with
water or semi-fluid substances containing a pulverulent body in suspension, I form
a bag or covering of cloth or fabric or very fine wire gauze one end of which
I attach to the edge x of the cap or plate at and the other end of which I secure to
the lower and middle part of the cap or plate a³ so that the said bag or covering is
spread over the inner surface of the lower cap or plate a¹. By this arrangement
when the upper cap or plate a³ is raised from the lower one a, the interposed cloth
or covering is also lifted up and the dried material deposited thereon in the form of
an annular cake is broken up and detached from the cloth and will be projected
more easily through the opening formed between the upper and lower caps or
plates a³ and a*.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A continuous acting centrifugal drying machine consisting of a lenticular
chamber or receptacle of symmetrical or other shape, mounted upon a rotatory
shaft or spindle, the said chamber or receptacle being composed of two metal saucer
shaped caps or plates juxtaposed so that at their periphery, they form a more or
less acute angle the upper cap or plate having round the shaft or spindle a circular
opening through which the material to be dried is fed continuously into the machine
and a concentric slit or opening of variable width being left between the said caps
or plates at their periphery, for the escape of the dried inaterials from the chamber
or receptacle substantially as hereinbefore described and illustrated in the accom-
panying drawings.
2. In a centrifugal machine, the combination with the rotating draining vessel
made of two perforated sections having a concentric discharge slit between the
same, of an elastic ring applied to the draining vessel and covering the discharge
slit until the pressure of the material is sufficient to remove said ring, substantially
as described.
3. In a centrifugal machine, the combination of the rotating draining vessel
having a concentric slit or opening and the permeable surface surrounding said slit
and against which the dried material issuing from the draining vessel is caused to
strike for the purpose of allowing any liquid parts adhering to the said parts of the
said material to separate therefrom and to escape through the said permeable
surface substantially as described.
4. In a centrifugal machine the devices described for raising and lowering the
upper cap or plate from or to the bottom cap or plate during the rotation of the
machine, that is to say by means of a lever turning upon a standard and connected
to a projected neck formed upon the upper cap or plate or by means of a screw box
formed within the said projecting neck, taking onto a screw upon a prolongation of
the shaft or spindle carrying the rotatory chamber or receptacle substantially as

page_text: and for the purpose described, also in combination with the said centrifugal
machine, an elastic cloth or fabric so secured to the under cap or plate a' and to the
upper cap or plate as that, on the raising of the upper cap or plate, it will be lifted
up with the dried material upon it, the said material being detached therefrom,
broken up and projected from the machine by centrifugal power, substantially as
described.
W
BROOKES & SON,
55 & 56 Chancery Lane, London,
Agents for the said
Edward Charles Roettger.