IMPROVED APPARATUS FOR FILTERING AND PURIFYING " SEWAGE
Year: 1877

page_text: LETTERS PATENT to Millington Henry Synge, of the United Service Club,
Pall Mall, in the County of Middlesex, Major General, Royal Engineers, for
the Invention of IMPROVED APPARATUS FOR FILTERING AND PURIFYING
"
SEWAGE"
Sealed the 20th October 1877, and dated the 25th April 1877.
PROVISIONAL SPECIFICATION left by the said Millington Henry Synge at
the Office of the Commissioners of Patents on the 25th April 1877.
MILLINGTON HENRY SYNGE, of the United Service Club, Pall Mall, in the County
of Middlesex, Major General, Royal Engineers. IMPROVED APPARATUS FOR
FILTERING AND PURIFYING SEWAGE"
65
The object of my Invention is to effect in a convenient and easy manner the
separation of the liquid from the solid matters of sewage. This has frequently been
attempted to be done by allowing the mixed matters to run on to filtering surfaces,
through which the liquids would in time percolate, leaving the solid matter behind.
It has been found however that when the filtering beds are arranged in the manner
usually adopted they are apt to get clogged very soon, and must therefore be
frequently cleansed. This is very inconvenient, and as it requires a great deal of
hand labor, not only to remove the solid matters but also to cleanse and replace the
filtering materials, it is an expensive and laborious operation.
By arranging the filtering beds in the manner hereafter explained I facilitate the
filtering operation and reduce to a minimum the cost of cleansing the filtering
surfaces, and at the same time I dispense with the necessity of stopping the filtering
process for the purpose of cleaning the filters.
My improved apparatus consists of a frame or inclosure containing one, two, or
more filters, onto which the mixed sewage is poured or allowed to run from any
suitable channel The meshes of this filter are rather large, and are only intended
to keep back the grosser or larger solid matters, which (as they accumulate on the
filters) are removed therefrom, either by hand or by a slowly-moving scraper
actuated by mechanical means. The semi-liquid matters thus freed from the larger
foreign substances pass through the filter and fall on to a second filtering surface
below, made with finer meshes and covered with straw, rushes, hay, or analagous
material

page_text: The solid deposit is removed from this filter, as in the former instance, while the
liquid passes through and falls on to a plate or surface, which may be slightly
inclined, and is provided in front with a finely perforated vertical side plate, through
which the supernatant liquid flows and falls into a vessel or trough with a porous
or perforated round, curved, or other shaped bottom, covered or not with matting.
The liquid on passing through this falls on to a level or an inclined perforated plate
or plates, which may also be covered with matting, so as to keep back as much as
possible of the solid matters which are floating about in the liquid.
The clarified liquid on passing through this last filtering surface falls into a
depositing tank, and any insoluble solid matters which it may still contain will
gradually sink to the bottom of the tank, and the clear liquid will run off by
decantation through a suitable opening provided for the purpose at the upper part
of the tank. The liquid thus strained off may finally be again forced to pass
upward through a layer of straw or other material, as above supported, in the
manner described, and may be dealt with in any manner desired, that is, it may
be used for irrigation purposes, or it may be subjected to distillation, to remove
the ammonia, or otherwise dealt with. In this manner a perfect separation of the
liquids from the solids may be effected by a continuous system of filtration, and the
filtering surfaces can be cleansed without necessarily stopping the process. The
solid matters, and the deposits from filtration will then be ready and in the best
form for the subsequent treatment to which they are to be subjected, and the liquid
will by the clarification it has undergone be in a like condition.
"
The following is a mode of applying this principle to the sanitary pan and to
cesspits-It being the custom (in some inland towns more especially) to employ
sanitary pans," or in other terms small portable receptacles or privies usually made
of metal, which compel a perpetual carriage of a dead weight of metal, I reduce this
expense to a minimum by introducing a perforated moveable strainer at an optional
distance from the bottom. The solid is retained above, while the liquid passes to
the bottom. A deodorant, if used, covers the top, very little of the deodorant being
required, and when the pan requires emptying the solids and liquids can be at once
collected separately.
Another mode of still further facilitating this object is to perforate the bottom of
the pan, or to insert in it a vertical strainer. In either of these latter cases the
pan is placed over an Alver trap filled with charcoal or other deodorant, through
which the liquid passes into a water-tight tank or pit, whence it is removed as
required, and by preference by a pneumatic cart.
The same principle is applicable to cesspits, which by this means are kept
inoffensive. The necessity for emptying them is reduced to a minimum, and the
liquid from any number of houses may be combined into one or other number of
large tanks, whilst the traps filled with deodorant prevent any communication of
gases.
The perforated separator may be introduced in any manner that may be preferred,
and an overflow and low level discharge be both introduced.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Millington Henry Synge in the Great Seal Patent Office on the 25th
October 1877.
MILLINGTON HENRY SYNGE, of the United Service Club, Pall Mall, in the County
of Middlesex, Major General, Royal Engineers. "IMPROVED APPARATUS FOR FILTER-
ING AND PURIFYING SEWAGE."
The object of this Invention is to effect in a convenient and easy manner the
separation of the liquid from the solid matters of sewage or excreta. This has
frequently been attempted to be done by allowing the mixed matters to run on tọ

page_text: filtering surfaces, through which the liquids would in time percolate, leaving the
solid matter behind. It has been found however that when the filtering beds are
arranged in the manner usually adopted they are apt to get clogged very soon,
and must therefore be frequently cleansed. This is very inconvenient, and as it
requires a great deal of hand labour, not only to remove the solid matters but
also to cleanse and replace the filtering material, it is an expensive and laborious
operation.
Now by arranging the filtering beds in the manner herein-after explained I
facilitate the filtering operation and reduce to a minimum the cost of cleansing the
filtering surfaces, and at the same time I dispense with the necessity for stopping
the filtering process for the purpose of cleansing the filters.
In the accompanying Drawings Fig. 1 shews in plan view a set of filtering beds
and receivers arranged according to this Invention; Fig. 2 is a transverse vertical
section of the same taken in the line 1, 2, of Fig. 1; and Fig. 3 is a sectional
elevation of the depositing tank taken in the line 3, 4, of Fig. 1.
The filtering apparatus it will be understood may consist of any number of
filtering beds, according to the amount of work to be performed. In the Drawing I
have, by way of illustration, shewn six filtering beds, three of which are raised at
a sufficient height to allow of their discharge being delivered on to the lower
beds.
The filtering beds are represented as contained in rectangular compartments
A, A, A, and A', A', A', built of brick, and with slightly inclined floors, to facili-
tate the flushing of the compartments when they require cleansing.
The filtering beds in the compartments A, A, A, are supported on girders a, a,
upon which is laid wirework, say, of one inch mesh to receive a layer of straw.
Above this are other girders supporting a similar arrangement of wirework, also to
receive a layer of straw, and above this is wirework of, say, two-inch mesh suitably
supported to receive also a layer of straw; these layers constitute the filter bed B.
The compartments are covered by removeable planks a¹, over the joints of which
may be scattered charcoal or other deodorant, to prevent the escape of noxious
gases. The compartments A¹, A¹, A¹, are similarly fitted with filtering beds B and
covers a¹, the wirework being however of sinaller mesh, the lowermost having a
mesh, say, of half an inch, and the two upper ones of, say, one inch. On the lower-
most wirework I prefer to place a layer of matting in addition to the straw, in
order to ensure a finer filtration than is effected in the first filter bed. In each case
an air space should be allowed between the layers composing the filter beds.
The several compartments A are connected respectively with the compartments A¹
by means of overflow pipes b fitted with stop-cocks. These pipes are set a little below
the beds of the filters in the compartments A, and at a suitable level with respect to
the compartments A¹, for running the filtered liquor as it accumulates below the
filter beds on to the filter beds of the compartments A¹. C, C, is a horizontal pipe
connected by branches with the several compartments A³, and leading to a depositing
tank D, and by a branch C¹ to a depositing tank D¹; these tanks are in connection
by means of the branch pipe E, E, with the reservoir F. Stop-cocks c are provided
in the branches of the pipe C (to cut off communication at pleasure) between that
pipe and the several compartments and tanks with which it is connected. G, G, is
à brick channel running by the side of the compartments A', and communicating
therewith by a sliding door g. This channel, which may connect with any
convenient sewer or watercourse, is intended to receive the flushings from the com-
partments and conduct them to any convenient discharge.
The receiving tanks D, D¹, are divided into three compartments by means of the
transverse division plates d and the filter beds d³, d³, (see Fig. 3). These beds will
consist of a grating, or it may be wirework, covered, the one with matting and the
other with matting and cloth. On to the first the filtered liquor is discharged by
the pipe C or its branch C¹, as the case may be, and the liquor filtering through this
medium will accumulate at the bottom of the tank, where any solid particles still
contained in the liquor will settle, and the overflow liquor will pass up through the

page_text: second filter d³, and find its way through the pipe E to the reservoir F, from which
it may be raised and discharged into a second set of filters, if thought desirable, or
otherwise treated, as circumstances may dictate.
I have said that the compartments containing the filter beds are covered, so as to
permit of ready access to the interior. The object of this arrangement is to allow
of the contents of collecting carts, or of the sanitary pans or house receptacles for
excrement, being discharged from time to time into one or other of these compart-
ments, and then of their being closed to prevent the escape of noxious odours. It
may be desirable however to throw upon the matters thus discharged into the
filters some deodorizing material, which, mixing with the solid portions left on the
filter beds, will serve in the production of a compost or manure from a solid material,
removed from time to time from the filter beds.
In order to avoid as much as possible the labour consequent on clearing the solid
matter from the filter beds, and also the labour of carting excrement from dwelling
houses to the filtering station, I propose to introduce into general use in localities
where my improved filtering apparatus is employed the separating pan, shewn in
two forms at Figures 4 and 5, which are sectional elevations of sanitary pans con-
structed so as to allow the urine to drain away from the solid excrement, and permit
of the latter being separately treated. The sanitary pan, shewn at Fig. 4, consists
of a metal case a fitted with a perforated bottom band with a removeable close
cover c; this case a drops into a fixed trap d, which is intended to receive the
runnings from the vessel a, and discharge the same through a central pipe e into a
cesspit or closed tank, which may be common to several houses.
The liquid
received into this tank I remove from time to time, by preference with the aid of a
pneumatic cart, and discharge the same into the filtering apparatus. The trap d
may be supplied with liquid deodorant, such as a hydrocarbon oil, or in lieu of this
trap an alver trap, such as that described in the Specification of my Patent bearing
date the Twentieth day of January, One thousand eight hundred and seventy-four,
No. 254, may be employed (to arrest the gases arising from the cesspit), the same
being suitably shaped to receive the pan a. f is a short pipe fitted with a stop-cock,
and serving to run off the liquid from the pan when desired.
Fig. 5 shews a modification of the pan which, instead of the perforated bottom b,
is provided with a perforated plate near the front side of the vessel, to allow of the
urine being discharged into the trap.
The advantage of using this construction of pan is obvious, for not only is the
weight of the solid matter to be removed from the houses materially diminished by
the separation therefrom of the liquid discharged into the pan, but the capacity of
the pan for containing the solid substance is virtually greatly increased and the
necessity for so frequent removal of the pan and replacement by a fresh one, as
would be otherwise required, is avoided. Moreover, the facility for dealing with
the liquid is greatly increased, the filtration being a much more simple operation than
when the solid matter predominates in the material to be filtered.
In describing the operation of my filtering apparatus I have traced the course of
the liquid to the reservoir and through one set of apparatus only, but I may remark
that if desired the liquid may be raised from the reservoir and discharged onto any
one of the upper filter beds, and so allowed to run a second course through the
apparatus. When the liquor is sufficiently filtered it may, if sufficiently weak, be
used for irrigation purposes, or if strong it may be subjected to distillation, to
remove the ammonia therefrom; or it may be otherwise dealt with, as thought
desirable.
By the arrangement of apparatus above described it will be readily understood
that the filtering surfaces can be cleansed and renewed without interrupting the
process, it only being necessary, when it is desired to throw out of action the filter
beds which require cleansing or renewing, to turn off the cock c, and in like manner
one or other of the depositing tanks D, D³, may be thrown out of use. These tanks a
I prefer to close by a permanent cover, and to fit the same with a man-hole for
gaining access to the interior.

page_text: Having now set forth the nature of my Invention of " Improved Apparatus
for Filtering and Purifying Sewage," and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim, the filtering apparatus, constructed and operating as above
described.
In witness whereof, I, the said Millington Henry Synge, have hereunto set
my hand and seal, the Twenty-second day of October, in the year of our
Lord One thousand eight hundred and seventy-seven.
TT CIVIC