Improvements in Machinery or Apparatus for Heating, Cleansing, Straining, and Pressing Indigo.
Year: 1892

page_text: Date of Application, 18th Oct., 1892
Complete Specification Left, 18th July, 1893-Accepted, 2nd Sept., 1893
PROVIDIUNAL DIETTUATION.
Improvements in Machinery or Apparatus for Heating, Cleansing,
Straining, and Pressing Indigo.
'
I, HERBERT SAMUEL ELWORTHY, of 31, Gurney Road, Stratford, in the
County of Essex, Analytical Chemist, do hereby declare the nature of this invention
to be as follows :-
This invention relates to improvements in machinery or apparatus operating by
centrifugal force for the purpose of heating, cleansing, straining, and pressing
indigo.
The accompanying drawing is in illustration of my invention,
Figure 1 representing an ordinary centrifugal hydro-extractor, Figure 2 a hori-
zontal section of my improved apparatus, and Figure 3 a vertical section of part of
the latter.
Figure 4 shews a somewhat modified form of Figure 3.
In Figure 1, a is the vertical side of the outer casing, 6 the lid or cover hinged
at c, d the bottom of the outer casing, e escape pipe, f space between drum and outer
casing, gangle iron rib upon which the cover closes and rests, h h the vertical sides
of centrifugal drum, ia removeable annular lid at the top of the drum, k the bottom
of centrifugal drum, angle iron rib to which the bottom of drum is rivetted,
m copper cylinder inside drum containing driving shaft n keyed collar o and balance
rings p. 9 is a nut upon the end of the shaft, holding balance rings in position.
r steam pipe, ss supporting columns to which the outer casing is bolted. t radial
shaft of spring bearing, u u india rubber buffers or springs, v horizontal ring
supporting the radial shafts of the spring bearing, w helt pulley on vertical shaft,
* hemispherical bearing for vertical shaft, y phosphor bronze or other metal step
upon which the vertical shaft n revolves. z bed for hearing.
Figure 2 shews a horizontal section of the internal arrangement of centrifugal
drum for heating, cleansing, straining, and pressing indigo.
h is the perforated wall of the drum.
A pockets to receive the indigo, B perforated plates forming the outer walls of
the pockets A, C strengthening braces. for ditto, also perforated, D vertical
cylindrical braces for the side walls of pockets, m copper cylinder, E E E metal
tubes for applying steam or hot water to the indigo fecula in the pockets, F metal
boss or chamber to which the above tubes are attached, G metal pressure plate,
H slab of pressed indigo.
The dotted circle I indicates the inner line of the removed lid.
In Figure 3 m is the copper cylinder, k the bottom of drum, K T-pipe for steam
and hot water, L cock for steam, M ditto for hot water, N N flexible pipes
conveying steam and hot water, O stationary vertical pipe, bayonet jointed, and
flanged at the lower end, connecting the pipe K with distributing pipes and round
which the latter revolve. P' stuffing box revolving round vertical pipe, F central.
distributing chamber for steam and hot water, E E E pipes attached to ditto for
conveying steam and hot water to interior of pockets, R rose mouths of pipes. In
Figure 4 the sides of the cylinder m are shewn finely perforated, the ends of the
pipes E being inside them.
The precipitated indigo fecula is taken from the beating vat and the pockets A.
of the drum charged with a sufficient quantity to make slabs of the ordinary
thickness. The machine is then set in motion at a moderate rate of speed until the
greater part of the waste water has been expelled. Should any of the fecula pass
through at first with the waste water, it may be returned to the machine until the
water runs away clear.

page_text: Boiling water and steam, either together or separately, are then injected into the
compartments of the drum while the latter is still revolving, through the radial
pipes E which being brought in contact with the slightly consolidated slab of fecula,
is caused by the centrifugal force to percolate through the said fecula thereby
effectively cleansing it, and at the same time producing the same result as that
ordinarily obtained by boiling.
The steam and boiling water for this operation may be conveniently obtained
from the boiler of the engine used to drive the machine. When judged to be
sufficiently clean and heated or "boiled," the steam and hot water are turned off,
and the machine being stopped for a few moments, the pressure plates G Figure 2
are placed one in each pocket resting with their faces against the slab of fecula H,
and the machine is then set in motion at a high velocity until the slabs of indigo are
sufficiently pressed.
After removal from the pockets the slabs of indigo may be submitted to a final
pressure in a hydraulic or ordinary press if thought desirable.
When it is simply desired to strain, clean, and boil the indigo fecula, an ordinary
centrifugal hydro-extractor, as shewn in Figure 1, as commonly used in sugar
refineries, &c., may be used. Steam and boiling water being forced in through a
perforated pipe as r, or by a rose jet attached to a flexible or other pipe.
The sides of the drum or the pockets H may be lined either with fine wire gauze
or suitable cotton or canvas cloth of sufficiently close texture to prevent the passage
of the fecula, while at the same time allowing the waste water to be freely expelled
through the sides of the drum. The present tedious and laborious operations of
boiling, cleansing, straining, and pressing indigo, as ordinarily performed in indigo
factories, are thus effectively condensed into one continuous, rapid, and simple
operation.
Steel or other wire of high tensile strength may be wound round the drum of the
centrifugal in order to strengthen it.
I do not confine myself to any particular dimensions of the parts; the machine
may be made of such a size and of such proportions as are best adapted for the
purpose for which it is required.
If preferred, previous to placing the fecula in the machine it may be boiled by
the old method of direct firing or by steam and may then be transferred to the
centrifugal machine.
The radial division walls of pockets marked T in Figure 2 may be perforated by
holes or slots or replaced by wires to reduce weight, or may if preferred, be done
away with altogether.
In order to strengthen the "chord" plates B Figure 2 straight or curved
perforated braces may be placed between the chord plates and side of drum, and also
to strengthen side walls of pockets, cylindrical steel or other metal braces may be
placed in the triangular spaces between them, as shewn at D Figure 2. These
triangular spaces may also be covered if desired.
If desirable, a copper or other metal channel, having the form of an annular ring
with short pipes radiating from the bottom, may be placed on the top of the division
walls T Figure 2 of the pockets in the centrifugal drum. The radiating pipes lead
one into each pocket for the purpose of distributing the material to be pressed,
evenly in the pockets, the said material being poured into the channel while the
drum is revolving.
I use for preference cast-iron pressure plates, but any other suitable material may
be used.
The balance rings, as shewn at p, Figure 1, are not shewn in the plan of my drum
Figure 2, but may be used if necessary. Instead of six pockets as shewn, more or
less may be used.

page_text: COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus for Heating, Cleansing,
Straining, and Pressing Indigo.
I, HERBERT SAMUEL ELWORTHY, of 31, Gurney Road, Stratford, in the
County of Essex, Analytical Chemist, 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, that is to say :-
My invention relates to improvements in machinery or apparatus, operating by
centrifugal force, for the purpose of heating, cleansing, straining, and pressing
indigo.
In the drawing accompanying my Provisional Specification and which is in
illustration of my invention,
Figure 1 represents an ordinary centrifugal hydro-extractor, Figure 2 a horizontal
section of my improved apparatus, and Figure 3 a vertical section of part of the
latter.
Figure 4 shews a somewhat modified form of Figure 3.
In Figure 1, a is the vertical side of the outer casing, 5 the lid or cover hinged
at c, and d the bottom of the outer casing, e is the escape pipe, f space between
the drum and the outer casing, 9 angle iron rib upon which the cover closes and
rests, h, h, the vertical sides of the centrifugal drum, i a removeable annular lid at
the top of the drum, k the bottom of the centrifugal drum, I angle iron rib to
which the bottom of the drum is rivetted m copper cylinder inside drum, containing
driving shaft n keyed collar o, and balance rings p.
q is a nut upon the end of the shaft, holding the balance rings in position. - is a
steam pipe, ss supporting columns to which the outer casing is bolted, t radial shaft
va horizontal ring sup-
of spring bearing, u, u, india rubber buffers or springs,
porting the radial shafts of the spring bearing, wo belt pulley on vertical shaft,
a hemispherical bearing for vertical shaft, y phosphor bronze or other metal step
upon which the vertical shaft n revolves, and z bed for bearing.
Figure 2 shews a horizontal section of the internal arrangement of centrifugal
drum for heating, cleansing, straining, and pressing indigo.
h is the perforated wall of the drum.
A are pockets to receive the indigo, B perforated plates forming the outer walls
of the pockets A; C strengthening braces for the same, also perforated, D vertical
cylindrical braces for the side walls of pockets, m copper cylinder, E, E, E, metal
tubes for applying steam or hot water to the indigo fecula in the pockets, F metal
boss or chamber to which the above tubes are attached, G metal pressure plate,
H slab of pressed indigo.
The dotted circle I indicates the inner line of the removed lid.
In Figure 3 m is the copper cylinder, k the bottom of drum, K T-pipe for steam
and hot water, L cock for steam, M ditto for hot water, N N flexible pipes con-
veying steam and hot water, O stationary vertical pipe, bayonet jointed, and
flanged at the lower end, connecting the pipe K with distributing pipes, and round
which the latter revolve. P stuffing box revolving round vertical pipe, F central
distributing chamber for steam and hot water, E E E pipes attached to the
same for conveying steam and hot water to interior of pockets, R rose mouths
of pipes.
In Figure 4 the sides of the cylinder m are shewn finely perforated, the ends of
the pipes E being inside them.
The precipitated indigo fecula is taken from the beating vat, and the pockets A
of the drum h charged with a sufficient quantity to make slabs of the ordinary
thickness. The machine is then set in motion at a moderate rate of speed until the

page_text: I
greater part of the waste water has been expelled. Should any of the fecula pass
through at first with the waste water, it may be returned to the machine until the
water runs away clear.
Boiling water and steam, either together or separately, are then injected into the
compartments of the drum while the latter is still revolving, through the radial
pipes E which being brought in contact with the slightly consolidated slab of
fecula, is caused by the centrifugal force to percolate through the said fecula
thereby effectively cleansing it, and at the same time producing the same result as
that ordinarily obtained by boiling.
The steam and boiling water for this operation may be conveniently obtained
from the boiler of the engine used to drive the machine. When judged to be
sufficiently clean and heated or "boiled," the steam and hot water are turned off,
and the machine being stopped for a few moments, the pressure plates G Figure 2
are placed one in each pocket resting with their faces against the slab of fecula H,
and the machine is then set in motion at a high velocity until the slabs of indigo
are sufficiently pressed.
After removal from the pockets the slabs of indigo may be submitted to a final
pressure in a hydraulic or ordinary press if thought desirable.
When it is simply desired to strain, clean, and boil, the indigo fecula, an ordinary
centrifugal hydro-extractor as shewn in Figure 1, as commonly used in sugar
refineries and the like may be used, steam and boiling water being forced in through
a perforated pipe as r, or by a rose jet attached to a flexible or other pipe.
The sides of the drums or the pockets H may be lined either with fine wire
gauze or suitable cotton or canvas cloth of sufficiently close texture to prevent the
passage of the fecula, while at the same time allowing the waste water to be freely
expelled through the sides of the drum. The present tedious and laborious
operations of boiling, cleansing, straining, and pressing indigo, as ordinarily
performed in indigo factories, are thus effectively condensed into one continuous,
rapid, and simple operation.
Steel or other wire of high tensile strength may be wound round the drum of the
centrifugal machine in order to strengthen it.
I do not confine myself to any particular dimensions of the parts, as the machine
may be made of such a size and of such proportions as are best adapted for the
purpose for which it is required.
If preferred, previous to placing the fecula in the machine it may be boiled by
the old method of direct firing, or by steam, and may then be transferred to the
centrifugal machine.
The radial division walls of pockets marked T in Figure 2 may be perforated by
holes or slots or replaced by wires to reduce weight, or may if preferred, be done
away with altogetlier.
In order to strengthen the "chord" plates B, Figure 2, straight or curved per-
forated braces may be placed between the chord plates and side of the drum, and
also to strengthen side walls of pockets, cylindrical steel or other metal braces may
be placed in the triangular spaces between them, as shewn at D Figure 2.
triangular spaces may also be covered if desired.
These
If desirable, a copper or other metal channel, having the form of an annular
ring with short pipes radiating from the bottom, may be placed on the top of the
division walls T, Figure 2, of the pockets in the centrifugal drum.
The radiating pipes lead one into each pocket for the purpose of distributing the
material to be pressed evenly in the pockets, the said material being poured into
the channel while the drum is revolving.
I use by preference cast iron pressure plates, but any other suitable material
may be used.
The balance rings, as shewn at p, Figure 1, are not shewn in the plan of my
drum, Figure 2, but may be used if necessary. Instead of six pockets as shewn a
greater or less number may be used.

page_text: 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. The application of centrifugal force for the purpose of heating, cleansing,
straining, and pressing indigo, substantially as described.
2. The general internal design and arrangement of the centrifugal drum as shewn
at Figure 2 and consisting of pocket A, plate B, and drums and stays substantially
as and for the purpose described and illustrated."
3. The design and arrangement of revolving pipes for introducing steam and hot
water into the pockets of the drum whilst revolving by means of the pipes E,
stuffing box P, pipe O and cocks or valves M and N, substantially as described and
illustrated in Figures 3 and 4.
4. In combination with the pockets A, the separate pressure plates G,
substantially as and for the purpose described and illustrated.
Dated this 10th day of T... 1000
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.