IMPROVEMENTS IN MACHINERY OR APPARATUS FOR EFFECTING THE SEPARATION OF SOLID BODIES FROM EACH OTHER OR FROM LIQUIDS AND OF LIQUIDS FROM LIQUIDS."
Year: 1881

page_text: LETTERS PATENT to Harry John Smith, Ph.D., of Glasgow, in the County of
Lanark, North Britain, for an Invention of "IMPROVEMENTS IN MACHINERY
OR APPARATUS FOR EFFECTING THE SEPARATION OF SOLID BODIES FROM
EACH OTHER OR FROM LIQUIDS AND OF LIQUIDS FROM LIQUIDS."
PROVISIONAL SPECIFICATION left by the said Harry John Smith at the
Office of the Commissioners of Patents on the 28th October 1881.
HARRY JOHN SMITH, Ph.D., of Glasgow, in the County of Lanark, North-Britain.
"IMPROVEMENTS IN MACHINERY OR APPARATUS FOR EFFECTING THE SEPARATION
OF SOLID BODIES FROM EACH OTHER OR FROM LIQUIDS AND OF LIQUIDS FROM
LIQUIDS."
This Invention relates to certain improvements in the construction of machinery
or apparatus to be employed in effecting the separation of solid bodies from each
other or from liquids and of liquids from liquids.
The improved machine is constructed so that two circular or other shaped vessels
provided with inlets and outlets, which may be protected by filtering apparatus,
rotate together about the same axis, and whose edges, flanged and so arranged as
to obtain close and perfect contact, are brought together or separated during
rotation. Or the rims or flanges may be fitted closely by means of bolts or clamps,
and at the periphery ports or openings are formed, which may be closed or opened
during the rotation of the machine by devices specially designed for these
purposes.
In carrying out the Invention, according to a modification adapted for the
separation of chemical precipitates from fluids, or of bodies or substances heavier
than water from water, or of heavy liquids from lighter liquids, the improved
machine which I employ comprises two vessels, by preference slightly domed or
saucer-like in shape, fitted the one over the other, or with the upper vessel as a
cover for the lower, with a rubber or other washer between them if necessary to
[Price S1

page_text: form a close water-tight joint. In order to prevent separation of the vessels at
the flanges by centrifugal action the dome-shaped vessels are connected at their
rims or flanges so that the tops of the domes are towards each other, or so that the
one dome is towards the inner or concave side of the other; that is to say, the
section of the chamber enclosed by the vessels is either double concave or meniscus.
The lower vessel is fitted on a vertical rotating shaft passing up through it, and on
which the upper vessel may move or slide. The liquid or semi-liquid substance to
be treated is led into these vessels through inlet tubes from above, or through the
central shaft, and the heavier solid particles or liquids are separated from the
lighter liquids by centrifugal action, as hereinafter more particularly described.
Within the space enclosed by the two vessels round the axis of rotation is a
cylindrical partition fixed and fitted close to the top or bottom vessel, and having
a closed top and bottom. This partition may be perforated and covered with a
filtering medium and formed also with channels, or with inner concentric perforated
partitions covered in the same manner if desired for the escape of the filtered
liquid, and the annular compartment enclosed by each partition may be provided with
a stop-cock or valve. Ports or openings with or without check valves may be
formed underneath the partition, protected or not, as found desirable, by filtering
media leading to a pipe or outlet which passes up or down through the bottom and
top of the cylindrical partition, and which may be fitted with check valves. From
the sides of this pipe or outlet other outlets or pipes are placed which lead to
vessels without the machine. Instead of the partitions referred to, perforated
hollow discs, both sides covered_with_filtering-cloth,-felt,-or-other-filtering-media,
also covered if necessary by perforated plates, may be fitted round the central
shaft or other outlets, and may be of the full internal diameter of the vessels, to
intercept solid matter in the outflowing liquids, or these discs may be made of any
suitable filtering substance, such as charcoal. The perforated hollow discs which
act as filters are provided with means for carrying off the filtered liquid, either
through the central shaft and thence out of the inachine, or, as is preferred, by
means of an annular or other recess at the periphery of the hollow perforated discs,
into which the liquids filtering through the cloth or other material are caused to
flow by the centrifugal action. From the recess round the discs the liquid is led
through pipes leading through the casing of either of the rotating vessels, preferably
the lower, and the liquid may thence be discharged freely, or the pipes may be
connected to a single annular vessel provided with valves or other means of
trapping the liquid.
The mixture of liquids and solids to be treated is led down to the circular
vessels from a supply tank, which consists of an open circular vessel whose centre
is preferably in the axis of rotation, and which may have one, two, or more pipes
in its bottom, and fixed on each side of the axis of rotation. These pipes lead firstly
down along lines parallel or nearly parallel with the axis of rotation, and then at
angles to these lines through the partition (within the separating vessel) and its
sides or other convenient part. Or a pipe may be fitted whose centre and the axis
of rotation are one; or the shaft carrying the vessels may be hollow and fitted
with ports to form both inlets and outlets.
When the machine is set in motion and a certain velocity is attained, the mixed
solids and liquids are delivered into the circular inlet vessel or supply tank, and
pass thence through the inlet pipes or central ducts into the space formed by the
circular separating vessels, and whose edges must now be in perfect contact. The
solids pass in due course of time to the point furthest from the centre of rotation
forming annular layers, and the liquid passes through the ports or openings
underneath the bottom of the partition into the discharge pipe and thence through
pipes finally into a vessel without the machine. As soon as the solids arrange
themselves around the sides of the partition or on the central discs, the delivery of
mixed solids and liquids is stopped, the flanged edges of the circular vessel are
separated, preferably without stopping the machine, and through the opening thus
formed the solids, as mud or sludge, are thrown from the machine by reason of

page_text: centrifugal force. When the discharging is completed the edges of the vessels are
brought into contact again, and the procedure described is repeated.
The closing and separating of the vessels while rotating may be effected in a
number of different ways. In a convenient arrangement one of the vessels,
preferably the upper one or cover, is formed with a number of wedges or inclined
planes, ranged circumferentially round the upper surface near the rim or edge, and
the other vessel is fitted with small brackets carrying pulleys or friction rollers
immediately over the wedges or inclined cam surfaces. These pulleys or rollers
are so arranged in relation to the inclines or wedges that the rollers when over the
wedges may bear on and press down the upper vessel or cover into close contact
with the lower vessel, and by being moved off the wedges may allow the vessels to
move apart on their axis or open out. The operation of opening and closing the
circular vessels may be performed automatically if desired, in the first case by
causing the one vessel fixed to the rotating shaft to be retarded, while the acquired
momentum of the other makes it race or rotate past the first during a part of the
revolution, and thereby frees the wedges or inclines past the bearing rollers to
allow of the separation of the vessels; while for the closing movement the fixed
vessel may be made to overtake the loosely revolving vessel or cover, and cause
the rollers to mount on to the inclines or wedges to press the rims of the vessels
together. The extent of the motion of the rotating circular vessels over each other
may be limited by stops, and the extent to which the vessels may be opened will
be likewise limited and maintained in position by suitable devices. The opening
and closing of the vessels may be effected by hand by stopping the machine, and in
this case ordinary screw bolts or clamps may be used instead of the wedges and
rollers described.
In another modification of the improved machine the dome-shaped vessels are
formed and fitted in a manner similar to that already described, but the flanges
are constructed so as to form a number of ports or openings at intervals round the
periphery through which the separated solids are discharged, or the flanges may be
left at some distance apart for the same purpose. In these ports or in the space
between the flanges stop valves of suitable construction are fitted, which are
capable of being moved to open or close the discharge ports or outlet, either when the
machine is in motion or when standing. These valves may be made in the form of
rollers or wedges, closing from the interior against the ports or openings round the
periphery, or as sluices or stop cocks, facings of rubber or similar yieluing material
being in general provided to ensure perfect closing. These valves are operated by
any suitable mechanical means, such as by levers to which the valves are connected
outside, and which may be moved simultaneously by a sliding collar on the
rotating shaft; or the valves may be closed and opened by hydraulic pressure,
either through levers or direct by means of rams or plungers connected to the
valves and fitted in bar els carried within the vessels, or by means of cam surfaces
bearing on the back part of the valves.
In a modified construction of this arrangement of machine in which the solids
are discharged through ports and the vessels do not require to be separated for this
purpose, a considerable thickness of filtering cloth, felt, or similar material is
interposed between the flanges of the vessels; and the ports or openings for the
discharge of the solids are formed in each vessel on each side of this filtering
washer, the closing valves of these ports being made to bear on this yielding
cushion if desired. The felt or other material between the flanges may extend
inwards to the centre of the vessels, and also outwards beyond the flanges and will
serve as a filier for the escape of the liquids which will exude through the filtering
material and be driven off by centrifugal action, while the filtering substance being
Jaid flat in the plane of rotation there will be no tendency for the solids to be
forced into the pores of the filter by centrifugal action.
In certain processes wherein, for example, chemical re-agents are employed within
the machine to facilitate precipitation or to promote chemical processes, or in the
treatment of sewage or substances used in certain manufactures, such as those

page_text: used in soap-making, as, for example, palm oil, the separation of the various
products obtained; or the separation of liquids from liquids of different specific
gravity may be effected in machines of the kind described, means being provided
when necessary whereby the materials within the vessels may be stirred or
agitated.
Stirrers or agitators fitted within the vessels may be actuated by means of
gearing from a fixed central shaft within the hollow rotating shaft; or the spindles
or axes of rotation of the stirring or agitating devices may be carried through
stuffing boxes in the shell of either of the vessels, and be fitted with toothed or
friction gearing operated by means of an internal geared or friction wheel.
gearing may be readily arranged so as to be put out of action when desired during
the rotation of the vessels.
Such
Means may also be provided whereby a jet or jets of steam, air, or other gas or
fluids or solids may be injected into the vessels to facilitate the removal of the
liquid from the solid matter or sludge after separation by means of centrifugal
action or to effect chemical decompositions.
The mixture of solids and liquids to be separated may generally with advantage
be forced into the circular containing vessels under pressure, or otherwise the
liquid matter may be pumped out through a filtering medium.
When solids are to be separated from solids of different specific gravity, the
machine is so modified as to collect the lighter bodies near the axis of rototion.
For instance, if a mass of cinders, ashes, and small unburned coal are to be treated
the upper vessel or cover is made open above, or formed with cross bars carrying
an outer lower rim which is formed with ports or openings to allow the lighter
substances to be thrown out, and instead of the cylindrical partition being closed
at the top and fixed to the top circular vessel, there is an open vessel_with_n_
_ perforated_bottom-fixed-round-the-axis of rotation and also rotating, which
vessel can be raised to the ports in the rim and lowered at will during rotation.
The machine is filled with water or other fluid; the mass under treatment is
thrown into the machine; the lighter bodies, that is, the unburned or partially
burned coals, move towards the centre of rotation, and by raising the vessel with
the perforated bottom are thrown by means of the centrifugal force beyond the
machine. The edges of the vessel are then opened and the cinders and ashes and
water are thrown likewise out of the machine.
In machines of the larger sizes of any of the kinds described, the lower of the
.rotating vessels may be supported by means of wheels or rollers, placed either at
the periphery or intermediately between the periphery and the axis of rotation, or
in both positions.
These wheels or rollers may either be carried in bearings connected to the
vessels or in fixed bearings, and the motion of rotation of the vessels may be
derived from motion imparted to such carrying wheels if desired.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Harry John Smith in the Great Seal Patent Oflice on the
26th April 1882.
HARRY JOHN SMITH, Ph.D., of Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN MACHINERY OR APPARATUS FOR EFFECTING THE SEPARATION
OF SOLID BODIES FROM EACH OTHER OR FROM LIQUIDS, AND OF LIQUIDS FROM
LIQUIDS."
My said Invention relates to certain improvements in the construction of
machines or apparatus to be employed in effecting the separation of solid matter
from liquids, or of liquids from liquids.
The improved machine is constructed so that two circular or other shaped vessels
provided with inlets and outlets, which may be protected by filtering apparatus,
rotate together about the same axis, and whose edges, flanged and so arranged as
to obtain close and perfect contact, are brought together or separated during
rotation; or the rims or flanges of the vessels are fitted closely by means of bolts
or clamps to form a single vessel, and at the periphery ports or openings are
formed which may be closed or opened during the rotation of the machine by
devices specially designed for these purposes.
And in order that my said Invention and the manner of performing the same
may be properly understood, I have hereunto appended a Sheet of Drawings to
be hereinafter referred to, and representing several modifications of my improved
separating apparatus. In these Drawings the same reference letters are used to
mark the same or like parts where repeated.
Figures 1, 2, and 3, 4, are vertical sections and plans showing the improved
apparatus fitted up in a supporting framing; Figure 5 is an elevation, and
Figures 6 to 13 are vertical sections showing modifications of the separating
vessels detached from their driving mechanism and supporting frames.
In the modification shown by Figures 1 and 2, and which is adapted for the
separation of chemical precipitates from fluids, or of bodies or substances heavier
than water from water, or of heavy liquids from lighter liquids, the improved
machine comprises two vessels A, A', by preference slightly domed or saucer-like
in shape fitted the one over the other as a single vessel divided horizontally, the
upper vessel A serving as a cover for the lower A' with a rubber or other washer
between them if necessary to form a close water-tight joint at a, a. In order to
prevent separation of the vessels at the flanges by centrifugal action, the dome-
shaped vessels A, A', are connected at their rims or flanges a so that the tops of
the domes are towards each other, or it might be so that the one dome is towards
the inner or concave side of the other, that is to say, the section of the chamber
enclosed by the vessels A, A', is either "double concave or "meniscus." The
lower vessel A¹ is fitted to slide on a vertical rotating shaft B passing up through
it, and to which the upper vessel A is fixed by a collar b; or there may be two
separate shafts on the same axis. The shaft B is carried in a foot-step bearing B
in a cast iron bed piece or framing below, and at its upper end is fitted in a
journal bearing B2 in a framing carried by pillars B³. The liquid or semi-liquid
substance to be treated is led into these vessels from a tank above, discharging
through inlet tubes from above, or through a pipe B' fitting into or over the
shaft B, which is in this case made hollow and formed with inlet ports a¹ for the
"

page_text: purpose. A pulley C is fixed on the shaft B driven by means of a belt to cause
the vessel to rotate at a high velocity, and the heavier solid particles or liquids are
separated from the lighter liquids within the vessel by centrifugal action, as
hereinafter more particularly described.
Within the space enclosed by the two vessels round the axis of rotation is a
cylindrical partition A fixed or formed on the lower vessel A', and having a closed
top. This partition is perforated and covered with a filtering medium, and it may
also be formed with channels or with inner concentric perforated partitions covered
in the same manner if desired. Outlet pipes A2 are provided for the escape of the
filtered liquid. Perforated plates A³ are also fitted as a false bottom in the
vessel A', and also if desired against the inner side of the upper vessel, and these
plates A³ are covered with filtering cloth or other filtering medium, and protected
by perforated plates or wire-cloth over the filtering cloth. The filters A³ so formed
are fitted and fixed down against webs or bearing pieces A3 formed on the inner
sides of the vessels A, A¹, so as to leave spaces between the filters and the shells of
the vessels into which the liquids may collect, and whence they are allowed to
escape by pipes at. Instead of the partition A perforated hollow discs A³, either
or both sides covered with filtering cloth, felt, or other filtering media, also covered
if necessary by perforated plates, may be fitted round the central shaft B or other
outlets, as shown in the diagram, Figure 8, and may be of the full internal
diameter of the vessels-to-intercept-solid-matter-in-the-outflowing-liquids;-or-these-
discs may be made of any suitable filtering substance, such as charcoal. The per-
forated hollow discs A³ which act as filters are provided with means for carrying
off the filtered liquid either through the central shaft B, and thence out of the
machine, or by means of pipes or an annular or other recess A' underneath or
round the hollow perforated discs, into which the liquids filtering through the
cloth or other material is caused to flow by centrifugal action or pressure. From
the recess Around the discs the liquid is led through pipes a leading through the
casing of either of the rotating vessels, preferably the lower A¹, and the liquid may
thence be discharged freely, or the pipes at may be connected to a single annular
vessel outside provided with valves or other means of trapping the liquid.
When the machine is set in motion and a certain velocity is attained, the mixed
solids and liquids are delivered first into the inlet vessel or supply tank, and pass
thence through the inlet pipes or ducts or central shaft B into the chamber formed
by the circular separating vessels A, A¹, and whose rims or edges a must now be in
perfect contact. The solids pass in due course of time to the point furthest from
the centre of rotation forming annular layers, and the liquid passes through the
central filtering partition A or filters A³ into the discharge pipes a² or a¹, and
finally into a vessel without the machine. As soon as the solids arrange themselves
around the sides of the partition A² or on the central disces A³, the delivery of
mixed solids and liquids is stopped, the flanged edges a of the circular vessels A, A¹,
are separated without stopping the machine, and through the opening thus formed
the solids, as mud or sludge, are thrown from the machine by reason of centrifugal
force. When the discharging is completed the edges a of the vessels are brought
into contact again, and the procedure described is repeated.
The closing and separating of the vessels while rotating may be effected in a
number of different ways.
In one arrangement, shown in Figure 5, one of the vessels, preferably the upper
one or cover A, is formed with a number of wedges or inclined planes d ranged
circumferentially round the upper surface near the rim or edge , and the other
vessel is fitted with small brackets d' carrying pulleys or friction rollers d
immediately over the wedges or inclined cam surfaces. These pulleys or rollers d
are so arranged in relation to the inclines or wedges d, that the rollers when over
the wedges may bear on and press down the upper vessel or cover A into close
contact with the lower vessel A', and by being moved off the wedges & may allow
the vessels A, A¹, to move apart on their axis or open out. The operation of

page_text: opening and closing the circular vessel may be performed automatically if desired,
in the first case by causing the one vessel fixed to the rotating shaft B to be
retarded, while the acquired momentum of the other makes it race or rotate past
the first during a part of the revolution, and thereby frees the wedges d or inclines
past the bearing rollers d to allow of the separation of the vessels, while for the
closing movement the fixed vessel A¹ may be made to overtake the loosely
revolving vessel or cover A and cause the rollers to mount on to the inclines or
wedges to press the rims of the vessels together. The extent of the motion of the
rotating circular vessels A, A', over each other may be limited by stops, and the
extent to which the vessels may be opened will likewise be limited and maintained
in position by suitable devices.
In the arrangement shown in Figures 1 and 2, the lower vessel A' is drawn up
with its edges in close contact with the upper vessel A by means of a series of
radial levers D connected to a sliding collar D' on the shaft B, and at their outer
ends connected to upright rods or bars D attached to the lower vessel and passing
up through the shell of the upper vessel. An eccentric or campiece D is formed
on the end of each lever D, and when the lever is pressed down moves over and
bears hard against a roller D under it, fitted on the upper vessel, and draws up the
lower vessel into close contact with it. When the pressure on the levers D is
relieved, the lower vessel separates from the upper one by its own weight. The
collar D is raised or lowered to act on the levers D by means of a lever handle
with a forked end and rollers fitting in the groove d on the collar D', or the collar
may form the plunger of an hydraulic cylinder and be actuated by hydraulic
pressure. The opening and closing of the vessels may otherwise be effected by
hand by stopping the machine, and in this caso ordinary screw bolts or clamps may
be used.
In the modification of the improved machine illustrated by Figures 3 and 4, the
dome-shaped vessels A, A', are formed and fitted in a manner similar to that
already described, but the flanges a are constructed so as to form a number of ports
or openings a at intervals round the periphery through which the separated solids
are discharged, or the flanges may be left some distance apart all round for the same
purpose. In these ports a³ or in the space between the flanges, stop valves E of
suitable construction are fitted, which are capable of being moved to open or close
the discharge ports or outlets a³, either when the machine is in motion or when
standing. The valves are preferably made in the form of rollers E or wedges
jointed to a crosspiece E', to which rods or bars e passing out through the shell of
the upper vessel A are connected against the ports or openings u³ round the
periphery, as shown in Figures 3, 4, and 7, or as sluices E, as shown in Figures 6,9,
and 12, in which latter case the sluice valves E2 are fitted through stufling boxes e
in the flanges of the vessels in the top and bottom. The sluices E' are so formed
with ports in them, that when raised these ports are opposite the outlet ports a³,
and the solid material may be freely discharged. These valves are operated by
any suitable mechanical means, such as by the levers D, to which the valve rods e
are connected outside the vessels, and which may be moved simultaneously by the
sliding collar D on the rotating shaft B, or the valves may be closed and opened
by hydraulic pressure, either through these levers D, as already indicated, or direct
by means of rams or plungers connected to the valves and fitted in barrels carried
within the vessels or outside the vessels, according to the position of the valves, or
by means of cam surfaces bearing on the back part of the valves.
In a modified construction of this arrangement of machine (shown in the
sectional diagram Figure 9) in which the solids are discharged through ports, and
the vessels do not require to be separated for this purpose, a considerable thickness
of filtering cloth, felt, or similar material F covered by perforated plates is
interposed between the flanges of the vessels A, A, and the parts or openings for
the discharge of the solids are formed in each vessel on each side of the filtering
washer, the closing valves of these ports being passed through the felt F and formed

page_text: with ports in them. This construction of machine may be so modified that the
vessels may separate during rotation to discharge the solid material, or a single
vessel may be used and covered at either or both ends with a washer or thickness
of filtering material suitably protected, or a number of such open vessels may be
arranged one over the other with washers of filtering material between each vessel,
provision being made in each case for discharge of the solids, either by separating
the vessels and filters from each other, or by means of valves. The felt or other
material F between the flanges extends inwards to the centre of the vessels and
also outwards beyond the flanges A, A', and will serve as a filter for the escape
of the liquids which will exude through the filtering material and be driven off
by centrifugal action, while the filtering substance being laid flat in the plane of
rotation there will be no tendency for the solids to be forced into the pores of the
filter by centrifugal action.
In certain processes wherein, for example, chemical re-agents are employed
within the machine to facilitate precipitation, or to promote chemical processes, or
in the treatment of sewage or substances used in certain manufactures, such as
those used in soap-making, as for example palm oil, the separation of the various
products obtained, or the separation of liquids of different specific gravities, may be
effected in machines of the kind described, means being provided when necessary
whereby the materials within the vessels may be stirred or agitated.
Figure 12 is a sectional diagram showing stirring.or agitating-blades-G-fitted-on-
spindles C within the vessels A, A', actuated by means of bevel gearing g, from a
fixed central shaft G2 within the hollow rotating shaft B. Otherwise the spindle or
axis of rotation of the stirring or agitating devices may be carried through stuffing
boxes in the shell of either of the vessels and be fitted with to thed or friction
gearing operated by means of an internal geared or friction wheel fixed outside.
Such gearing may be readily arranged to be put out of action when desired during
the rotation of the vessels.
The agitation of the material within the vessels A, A', may be effected by means
of jets of steam admitted through the inlet ports or outlet pipes a², a', or through
other openings in the vessels A, A', or when the action of the steam might be
prejudicial, compressed air or other fluid may be injected for the same purpose.
Similar means may also be provided whereby a jet or jets of steam, air, or other
gas, or fluids, or solids may be injected into the vessels to facilitate the removal
of the liquid from the solid matter or sludge after separation by means of centrifugal
action, or to effect chemical decomposition.
The mixture of solids and liquids to be separated in closed machines as described
are generally with advantage operated upon under pressure or otherwise; the liquid
matter may be pumped out through a filtering medium, and the action of
separating the liquids and solids of the filtering arrangements may be facilitated
by pressure of steam, or of compressed air and steam; or compressed air of
considerable pressure introduced by the inlet or other openings may also be used
to force out the solids from the vessels after separation from the liquids, and to
clear the filters.
The
When solids which are lighter than the liquids in which they are immersed are
to be separated from such liquids within the machine, the vessels A, A', in any
of the arrangements described, are formed with perforations or openings round the
periphery, or on the upper and lower shells or casing of the vessels near the
periphery, such perforations or openings being covered with filtering media.
rotation of the vessels when filled will force the heavier liquids towards the
periphery, while the lighter solids will aggregate round the centre until the vessels
are filled, when the supply of mixed solids and liquids will be stopped, and the
vessels may be opened or separated during rotation to cause the solids to be thrown
out by centrifugal action; or means may be provided whereby the solids may be
removed as they accumulate, or after complete separation from the liquids through
the central shaft or openings close to it.

page_text: By use of the filtering arrangements herein before described, and where the
liquid is allowed to escape otherwise than through the central shaft of the machine,
as by pipes or chambers extending radially outwards, there is a tendency on the
part of the material within the machine to settle in alternate zones or rings of liquid
and of solid or semi-solid matter, the positions of the solid zones being in general
determined by the extent to which the outlet pipes for the liquid aro carried out
from the centre of the machine; and by the use of filters either arranged horizon-
tally, or as vertical annular partitions as described, or as radial partitions, it may
be found impracticable to withdraw the liquid without disturbing the solid zones.
To obviate the formation of such zones in some cases, and in other cases to take
advantage of such formation, I withdraw the liquid from the filters or partition
through pipes direct, or through a central chamber preferably on the bottoin of the
lower vessel, fitted with pipes, these pipes in each case being so fitted that the
distance of their outlets from the centre may be varied at will during rotation or
otherwise. In this way the centrifugal action on the material within the machine
and on the liquid escaping through the central chamber and pipes may be equalised,
or a greater or less tendency may be given to the solids to settle towards the
periphery of the vessel. When alternate zones of liquid and solid matter are thus
formed I introduce movable pipes a', as indicated in Figures 7 and 11, fitted with
cocks or valves aº, or fixed pipes provided with movable valves, by which the
liquid may be drawn off from the closed vessels at any desired point. Such pipes
may be carried through the shell of one of the vessels, and kneed or bent within
the vessels, so that by turning the pipe its open end may be brought within the
liquid zone. These pipes when fitted for withdrawing the liquid in this manner
are by preference covered with cloth or other filtering medium, but in some cases
such pipes may be covered with perforated plates only, to draw off the semi-liquid
matter. The valves a may be operated so that either of the outlet pipes a* or a²
may be closed, or both closed or opened simultaneously as indicated in Figure 11,
in which the levers a, a³, operate the valves as of the inner and outer set of
pipes a², at, respectively; or the valves a' may be controlled by a single lever to
open the one set when closing the other, as is indicated in Figure 7.
When the solids to be separated are lighter than the liquids the order of formation
of the zones will be reversed, that is to say, the liquids will separate towards the
outer periphery and towards the annular partition A', while the solids will be left
as an intermediate zone.
Figure 10 shows a modification of the improved apparatus adapted for separating
solids from heavier liquids. The outer shell A* and cover are fitted together, and
rest on the bottom, which is in the form of a disc on the rotating shaft. The
material is led into the vessel by pipes B', and by the rotation of the vessel the
liquids are forced outwards towards the outer shell A*. The lighter solids aggregate
round the central partition or drum A³, and when completely separated the upper
part of the vessel is raised or the lower disc or bottom part lowered on the rotating
shaft, while the rotation is retarded to allow the liquid to escape; then the
velocity of rotation is increased, and the solid matter is thrown out by centrifugal
action.
In machines of the larger sizes of any of the kinds described the lower A' of the
rotating vessels A, A', may be supported by means of wheels or rollers J, as shown
in Figure 13, placed either at the periphery or intermediately between the periphery
and the axis of rotation, or in both positions. These wheels may either be carried
in bearings on brackets J', connected to the vessels as shown, and running on a
circular rail J, or they may be fitted in bearings fixed to the bed plate of the
machine, with the vessel A¹ resting over them. The motion of rotation of the
vessels A, A, may be derived from motion imparted to such carrying wheels J,
which may be fitted on rotating shafts for this purpose, or the motion may be
obtained from the central shaft B.
When the machine is driven by means of wheels or rollers on which the vessels

page_text: rest a central space, which in the other constructions of machines is occupied by
the driving vertical shaft may be left, as little or no separating action takes
place at the centre, in which case the vessel or vessels will be of an annular
form, and the central space may be conveniently utilised for the withdrawal
of the liquids, or in such machines, as stirrers or agitators are required, the
operating gearing or mechanism for driving such stirrers may be fitted within the
space. Stationary casings suitable to the particular construction of machine may
be fitted to surround the rotating vessels, such casings being in general constructed
of sheet metal and in the form of truncated cones to direct downwards or otherwise
the material which is discharged from the vessels. In my Provisional Specification
I described a modification of centrifugal apparatus adapted for separating solid
bodies from each other. I do not now consider the apparatus as therein described
to be practically applicable for the purpose described, and I do not therefore claim
that arrangement of apparatus as part of my present Invention. I am also aware
that the separation of liquids and solids has already been effected or attempted to
be effected in close vessels, the liquid being drawn off and the solid removed when
the vessels are not in motion. I therefore lay no claim to the mode or means of
separating liquids from solids in close vessels, except in such cases and with
machines so constructed that the liquids can be withdrawn during rotation, and
the solid material ejected or thrown out of the vessels by centrifugal action, either
by separating the containing vessels or opening ports in them during rotation of
the vessels.
What I claim to-be-novel-and-original, and thereforo claim as the Invention
secured to me by the herein before in part recited Letters Patent is,-
First. The construction of centrifugal machines or apparatus for separating
liquid and solid matters of different specific gravities, in which the containing
vessels (such as A, A', in Figures 1, 2, 5, 8, 10, 11, and 13) are by mechanical means
caused to open or close during rotation, substantially in the manner and for the
purposes herein specified.
Second. In centrifugal machines or apparatus for separating liquid and solid
matters of different specific gravities, the construction and fitting of ports or outlets
round the periphery, which may be opened or closed by valves or other equivalent
means during the rotation of the containing vessel or vessels, substantially in the
manner herein set forth in reference to Figures 3, 4, 6, 7, 9, and 12 of the accompanying
Drawings.
Third. The construction of centrifugal machines or apparatus for separating liquid
and solid matters of different specific gravities, in which the containing vessels or
outlet ports or openings formed in their peripheries are made to open or close
mechanically, in combination with means whereby the liquids are withdrawn either
direct or through filtering media during rotation of the vessels, substantially as
herein described in reference to the accompanying Drawings.
Fourth. The construction and fitting of centrifugal machines or apparatus for
separating liquid and solid matters of different specific gravities with filtering
appliances through which the liquids are withdrawn during rotation of the con-
taining vessels, such filters being arranged as central or annular perforated
partitions, or as discs fitted in the plane of rotation against the shells of the con-
taining vessel, or centrally or interinediately between the vessels, substantially as
herein described in reference to the accompanying Drawings.
Fifth. In combination with centrifugal machines or apparatus of the kind herein
described, the fitting of outlet pipes from the containing vessel or vessels A, A', to
cause the formation of zones of liquid and solid matter therein, and to lead off the
liquids therefrom, the opening and closing of such pipes being controlled by valves
operated either by mechanical means during rotation, or when the machine is not
in motion by hand, substantially as herein described in reference to the accoin-
panying Drawings.
Sixtb. In centrifugal machine or aparatus for separating liquid and solid matters

page_text: of different specific gravities, the construction and fitting of stirring or agitating
blades within the containing vessels for facilitating chemical or other processes, such
stirrers or agitators being operated by the rotation of the vessels, substantially as
herein described with reference to Figure 12 of the accompanying Drawings.
In witness whereof, I, the said Harry John Smith, have hereunto set my
hand and seal, this Twenty-fourth day of April, in the year of our Lord
One thousand eight hundred and eighty-two,
Witness,
WALLACE FAIRWEATHER, C.E.,
of W. R. M. Thomson & Co.,
Patent Agents,
Glasgow.
H. J. SMITH. (L.S.)