IMPROVEMENTS IN THE MEANS AND MACHINERY AND STRAINING LIQUIDS. ESPECIALLY OR APPLIANCES FOR FILTERING APPLICABLE FOR STRAINING SEWAGE
Year: 1869

page_text: LETTERS PATENT to Baldwin Latham, of No. 6, Westminster
Chambers, Victoria Street, Westminster, in the County of Middlesex,
for the Invention of "IMPROVEMENTS IN THE MEANS AND MACHINERY
AND STRAINING LIQUIDS. ESPECIALLY
OR APPLIANCES FOR FILTERING
APPLICABLE FOR STRAINING SEWAGE'
Sealed the 13th July 1869, and dated the 17th March 1869.
PROVISIONAL SPECIFICATION left by the said Baldwin Latham at the
Office of the Commissioners of Patents, with his Petition, on the
17th March 1869.
I, BALDWIN LATHAM, of No. 6, Westminster Chambers, Victoria
Street, Westminster, in the County of Middlesex, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MEANS AND
MACHINERY OR APPLIANCES FOR FILTERING AND STRAINING LIQUIDS, ESPECIALLY
APPLICABLE FOR STRAINING SEWAGE," to be as follows:-
My Invention consists in causing the sewage or other fluid to be
filtered to pass on its way along or as it issues from a conduit, against
and through a travelling screen or sieve or combination of screening
[Price 8d.1

page_text: surfaces arranged at right angles or at any other convenient angle to
the flow of the fluid, whereby the sewage or other fluid as it passes
through the screening surfaces deposits its solid matter upon the latter,
which in travelling along carries such matter away to a point where it
is removed from the surfaces, and these then again pass into the stream
of sewage to intercept fresh matter.
A variety of arrangements of apparatus or machinery may be employed
for carrying my Invention into practice. Thus, in one arrangement the
travelling screen may be in form of a hollow wheel or drum, either
cylindrical or polygonal, rotating on a central shaft, the one end surface
of which drum is formed as a screen, while the other end surface is open
for the sewage to enter it, and radially or obliquely in the drum are
arranged a number of other screens revolving with the drum, upon
which screens as also on the screening end surface, the solid matter of
the sewage is deposited as they pass through the latter. As these
screening surfaces pass round the solid matter falls off them into a
semicircular trough partly surrounding the central shaft, and in order
to clear the screening surfaces more effectually from the adhering solid
matter, brushes or scrapers are arranged at one or more places above
the level of the fluid acting against the end screening surface so as to
remove the deposited matter therefrom, or a jet of water may be employed
for this purpose; also at the circumference of the drum or wheel troughs
may be arranged running parallel with the axis of the drum, in which
troughs some of the fluid may be caught up, and when raised to a
certain height such fluid is made to flow on to the radial screens and
to wash the deposited solid matter therefrom into the before-mentioned
trough or receptacle partly surrounding the shaft of the drum. To
facilitate this the said screens may be constructed of parallel transverse
bars placed at such an angle that when raised into the position in which
the fluid falls upon them from the troughs they are in a more or less
horizontal position. Upon the shaft of the drum may be fixed an
archimedian screw, which in revolving in the before-mentioued trough
conveys the deposited matter to one end, where it is made to pass
through an opening into another trough or channel for conveying it to
wherever required, and in which another revolving screw or other known
contrivance may be arranged for facilitating its conveyance. The drum
or wheel may also be divided by partitions (either constituting screens
or otherwise) parallel with the end surfaces into two or more com-

page_text: partments having screened surfaces of different fineness, so as to sort
the solid matter in correspondingly different degrees of fineness, or
two or more separate screening wheels or drums of different degrees
of screening power may be arranged behind each other, revolving
either upon the same shaft or on different shafts and either at the
In some cases the radial screens may
same or at different speeds.
be dispensed with and a fixed brush or scraper may be used, which
shall brush or scrape the inner end face of the perforated wheel,
and in connection with the brush or scraper a trough may be used for
conveying the matter either into the central trough of the wheel or to
the exterior of the wheel. Also in place of a wheel or drum a simple
disc with or without radial screens may be employed. In some cases
the outer face of the wheel may be wholly or partly closed, and
perforations may be made in the skin or sole plate of the wheel, which
openings will be so arranged as to be protected by the gratings, of the
Or in some cases the sole
screens fixed in the interior of the wheel.
plate may be made perforated in the manner described for the end
surface of the wheel. The wheel may have a shrouding either solid or
perforated, or a combination of both. The motive power when water
or other fluid is being treated may be applied direct to the shaft of the
apparatus by fixing thereon a water wheel of any known description
applicable for the purpose, or a portion of the apparatus may be made
to act as a water wheel, or the gratings for straining may have the bars
placed at an angle with the direction of the flow of the fluid to be
strained, so that as the fluid impinges on the inclined face of the bars
a rotating motion may be given to the wheels. Or the fluid as it arrives
at the apparatus may be made to give a rotary motion to it by means of
suitable and known appliances, such as turbines, undershot, breast, and
overshot wheels, or by means of vanes acted on by the current, or by
making the outer casing of the apparatus to act as a water wheel, the
buckets of which discharge into the interior of the wheel, or by
applying an apparatus similar to the curved bucket of a turbine to the
periphery of the wheel. Discs without radial screens may have a brush
or scraper which shall remove all material adhering to the perforated
side. The arms for supporting the brushes may be attached to the tank
or receptacle into which the fluid flows. In some cases, the brushes may
be hinged and weighted to adjust themselves to the face of the wheel,
and in this case the wheel or disc may be placed either vertically or
obliquely on the shaft. The screening surfaces may be constructed

page_text: either of gratings, bars, rods, plates, wires, wire gauze, perforated plates,
or canvas or other known straining or filtering medium, such as charcoal,
or a combination of any of these.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Baldwin Latham in the Great Seal Patent Office
on the 16th September 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BALDWIN
LATHAM, of No. 6, Westminster Chambers, Victoria Street, Westminster,
in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of March, in the year
of our Lord One thousand eight hundred and sixty nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Baldwin Latham, Her special licence
that I, the said Baldwin Latham, my executors, administrators, and
assigns, or such others as I, the said Baldwin Latham, my executors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MEANS
AND MACHINERY OR APPLIANCES FOR FILTERING AND STRAINING LIQUIDS, ESPECIALLY
APPLICABLE FOR STRAINING SEWAGE," upon the condition (amongst others)
that I, the said Baldwin Latham, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Baldwin Latham, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained

page_text: in and by the following statement thereof, reference being had to the
accompanying Drawings, and to the Figures and letters marked thereon,
that is to say :-
My Invention consists in causing the sewage or other fluid to be
filtered to pass on its way along or as it issues from a conduit, against
and through a travelling screen or sieve or combination of screening
surfaces arranged at right angles or at any other convenient angle to the
flow of the fluid, whereby the sewage or other fluid as it passes through
the screening surfaces deposits its solid matter upon the latter, which in
travelling along carries such matter away to a point where it is removed
from the surfaces and these then again pass into the stream of sewage to
intercept fresh matter.
A variety of arrangements of apparatus or machinery may be employed
for carrying my Invention into practice. Thus, in one arrangement the
travelling screen may be in form of a hollow wheel or drum, either
cylindrical or polygonal, rotating on a central shaft, the one end surface
of which drum is formed as a screen, while the other end surface is open
for the sewage to enter it, and radially or obliquely in the drum are
arranged a number of other screens revolving with the drum, upon which
screens as also on the screening end surface, the solid matter of the
sewage is deposited as they pass through the latter. As these screening
surfaces pass round the solid matter falls off them into a semicircular
trough partly surrounding the central shaft, and in order to clear the
screening surfaces more effectually from the adhering solid matter
brushes or scrapers are arranged at one or more places above the level of
the fluid acting against the end screening surface, so as to remove the
deposited matter therefrom, or a jet of water may be employed for this
purpose, also at the circumference of the drum, or wheel troughs may be
arranged running parallel with the axis of the drum, in which troughs
some of the fluid may be caught up, and when raised to a certain height
such fluid is made to flow on to the radial screens and to wash the
deposited solid matter therefrom into the before-mentioned trough or
receptacle partly surrounding the shaft of the drum. To facilitate this
the said screens may be constructed of parallel transverse bars placed at
such an angle that when raised into the position in which the fluid falls
upon them from the troughs they are in a more or less horizontal position.
Upon the shaft of the drum may be fixed an archimedian screw, which
in revolving in the before-mentioned trough conveys the deposited matter

page_text: to one end, where it is made to pass through an opening into another
trough or channel for conveying it to wherever required, and in which
another revolving screw or other known contrivance may be arranged for
facilitating its conveyance. The drum or wheel may also be divided
by partitions (either constituting screens or otherwise) parallel with the
end surfaces into two or more compartments, having screening surfaces
of different fineness, so as to sort the solid matter into correspondingly
different degrees of fineness, or two or more separate screening wheels
or drums of different degrees of screening power may be arranged
behind each other, revolving either upon the same shaft or on different
shafts, and either at the same or different speeds. In some cases the
radial screens may be dispensed with and a fixed brush or scraper may
be used, which shall brush or scrape the inner end face of the perforated
wheel, and in connection with the brush or scraper a trough may be used
for conveying the matter either into the central trough of the wheel or
to the exterior of the wheel. Also in place of a wheel or drum a simple
disc with or without radial screens may be employed. In some cases the
outer face of the wheel may be wholly or partially closed, and per-
forations may be made in the skin or sole plate of the wheel, which
openings will be so arranged as to be protected by the gratings of the
screens fixed in the interior of the wheel. Or in some cases the sole
plate may be made perforated in the manner described for the end
surface of the wheel. The wheel may have a shrouding either solid or
perforated or a combination of both. The motive power when water or
other fluid is being treated may be applied direct to the shaft of the
apparatus by fixing thereon a water wheel of any known description
applicable for the purpose, or a portion of the apparatus may be made
to act as a water wheel, or the gratings for straining may have the bars
placed at an angle with the direction of the flow of a fluid to be strained,
so that as the fluid impinges on the inclined face of the bars a rotating
motion may be given to the wheels. Or the fluid as it arrives at the
apparatus may be made to give a rotary motion to it by means of suitable
and known appliances such as turbines, undershot, breast, and overshot
wheels, or by means of vanes acted on by the current, or by making the
outer casing of the apparatus to act as a water wheel, the buckets of
which discharge into the interior of the wheel, or by applying an
apparatus similar to the curved bucket of a turbine to the periphery of
the wheel. Discs without radial screens may have a brush or scraper
which shall remove all material adhering to the perforated side. The

page_text: arms for supporting the brushes may be attached to the tank or
receptacle into which the fluid flows. In some cases the brushes may be
hinged and weighted to adjust themselves to the face of the wheel, and
in this case the wheel or disc may be placed either vertically or obliquely
on the shaft. The screening surfaces may be constructed either of
gratings, bars, rods, plates, wires, wire gauze, perforated plates, or
canvas, or other known straining or filtering medium, such as charcoal,
or a combination of any of these.
Having thus set forth the nature of my Invention I will now proceed
more particularly to describe some of the various modifications I employ
for carrying the same into practice, for which purpose I shall refer to
the accompanying Sheets of Drawings.
Figure 1 shews a sectional side elevation of one arrangement,
Figure 2 shews a plan of the same, and Figure 3 shews a front elevation
thereof.
A is a hollow wheel or drum, the circumference of which is of sheet
metal, and which is open at the front face a, which is presented to the
stream of sewage or other matter to be filtered flowing in the direction
of the arrow through the culvert or channel B. The back face of the
wheel is closed by a screen 6 formed either of perforated plate, as shewn,
or of gratings of the requisite degree of fineness, and if requisite a
second screen c formed of gratings with larger apertures than b is fixed
in the middle of the wheel to intercept the coarser portion of the solid
matter. The wheel is carried by the shaft C to which it is secured by
the strong cast-iron boss d and ribs e, and it receives a slow rotary
motion in the direction of the arrow by means of gearing D, D', from a
turbine at E driven by the head of sewage water flowing through the
apparatus. Inside the wheel A are fixed a number of radial screens f, f.f,
by preference formed as a step grating, as shewn at the enlarged detail
section and part plan at Figures 4 and 5, the inclined transverse bars
being intersected by longitudinal bars, as shewn, so as to form
apertures of a small size. In place of such step gratings may be em-
ployed perforated plates, or even solid plates, or an arrangement may be
advantageously used, as shown at Figure 6, where a screen f¹ of perforated
plates is fixed immediately above the step grating f
The before-described construction of step gratings is also applicable,
irrespective of its combination with the screening wheel for separating
solid from liquid matter, thus they may be fixed in an inclined position

page_text: and the liquid in which the solid matter is held in suspension be made
to flow down them. At the outer ends of the screens are formed either
fixed troughs g, as at Figures 3 and 6, or a tumbling trough g', as at
Figures 4 and 5, turning on pins h, which troughs take up fluid as the
wheel revolves, and when the screens have been raised to a certain angle
the fluid flows out of the troughs and down the screens, flushing the.
solid sewage deposited thereon into the central trough i. At the same
time the solid matter deposited upon the vertical screen 6 (as also on the
intermediate screen c, when this is employed) by the passage through it
of the sewage water also passes down on to the screens f, to facilitate
which brushes j carried by hinged arms, as shown, may, if necessary, be
kept in contact with the outer surface of the screen b, or jets of water
directed against the screen may be employed for this purpose, but the
rushing back of the sewage water through the apertures of the screen on
the descending side of the wheel as it dips into the fluid will generally
be found sufficient to flush the deposited matter off the vertical screen
on to the radial ones. As the separated solid sewage passes into the
central trough i it is carried forward in the same by the revolving screw
blade fixed on the shaft C, so as to fall either into trucks F' run upon
rails G underneath the trough, the front end of which is provided with a
sliding door for this purpose actuated by a handle m. Or the
trough may be made to deliver continuously into a second trough, as
shown at n in part plan at Figure 7, in which it may be carried
forward either by another revolving screw blade o, driven by gearing o'
from the shaft C, or by chain buckets. In order to gain access to the
radial screens for cleansing them when required man-holes p provided
with covers are formed in the circumference of the wheel. Both faces of
the wheel are provided with shroudings q for the purpose of catching and
retaining sand passing in with the sewage, and to strengthen the wheel,
and which also serve to close the ends of the troughs f. The sewage
water or other fluid holding solid matter in suspension after flowing
through the screening apparatus passes through the channel H and
sluice I to the turbine chamber E, whence it flows down the aperture K
to the low level culvert L.
As before stated the construction of the before-described apparatus
may be greatly varied. In place of effecting the rotation of the wheel
by means of a turbine or waterwheel, as described, the action of the
fluid upon the apparatus itself may be made to effect its rotation either

page_text: by forming the vertical screen of a grating with oblique bars, against
which the fluid is made to impinge, or an arrangement may be employed
as indicated in part front elevation, vertical section, and sectional plan"
at Figures 8, 9, and 10, in which the front surface of the drum is
formed with an annular opening near the periphery, in which are curved
vanes or blades s similar to those of a turbine or waterwheel, against"
which the fluid has consequently to impinge on entering the drum
through the shoot t, and whereby it is consequently caused to drive the
drum round in the direction of the arrow.
Should it be required still further to strain. the sewage after passing
through the above-described apparatus it may be caused to flow through
a second wheel or disc covered with canvas or other suitable straining
material which may be arranged as indicated in transverse section and
front elevation at Figures 11 and 12 on Sheet II., where A is an inclined..
revolving wheel covered at a with canvas or other suitable straining
material through which the sewage is made to flow in the direction of
the arrow, and upon which the solid matter yet contained therein is
consequently deposited. As the straining surface revolves it carries such
deposited matter round to the fixed scraper B in contact with the
straining surface, which consequently removes the deposited matter and
causes it to pass into the trough C attached thereto, or formed in one,
therewith, in which trough it is conducted to wherever required. Two
or more such straining discs of different degrees of fineness may also be
fixed one behind the other upon one and the same shaft.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be understood that I
in no way limit myself to the arrangements thereof shown on the
accompanying Drawings, as these only serve to indicate some of the
various modes in which it may be carried into effect, but what I
claim is,―
First. Constructing apparatus for separating the solid from the liquid
matter of sewage or other fluids, wherein a travelling screen or combina-
tion of screens is or are caused to pass through the sewage or other fluid
at right angles, or at any convenient angle to its flow, upon which
screen the solid matter is deposited from the sewage or other fluid, and is
conveyed away to a point where it is removed from the screen, sub-
stantially as described.

page_text: Second. Constructing apparatus for separating the solid from the
liquid matter of sewage or other fluids, consisting of a revolving drum or
wheel, having one or more vertical screening surfaces and a series of
radial screens or solid surfaces, from which the deposited matter is
caused to flow into a central receptacle, whence it is conveyed to
wherever required, substantially as described.
Third. The employment of one or more revolving, vertical, or inclined
screening discs without radial screens, substantially as described with
reference to Figures 11 and 13 of the Drawings.
Fourth. The application of fixed or tumbling troughs at the outer
ends of the radial screens for the purposes set forth.
Fifth. So constructing the screening apparatus that the flow of the
sewage through the same shall directly impart to it the requisite rotary
motion, substantially as described.
Sixth. The employment of step gratings, as herein-before described
with reference to the accompanying Drawings, whether fixed or moveable
for separating solid matter from liquids.
Seventh. I claim the general arrangement of apparatus for straining
sewage and other liquids herein-before described, with reference to the
accompanying Drawings.
In witness whereof, I, the said Baldwin Latham, have hereunto set
my hand and seal, this Fourteenth day of September, in the
year of our Lord One thousand eight hundred and sixty-nine.
BALDWIN LATHAM. (L.s.)