IMPROVED ÅRRANGEMENTS FOR FILTERING AND PURIFYING, ALSO "FOR COLLECTING FOR UTILISATION THE SOLID MATTER IN SUSPENSION IN SEWAGE ESPECIALLY APPLICABLE FOR OFTAINING PURE POTABLE WATERS
Year: 1871

page_text: LETTERS PATENT to James Brough Pow, of Worcester, for the Inven-
tion of "IMPROVED ÅRRANGEMENTS FOR FILTERING AND PURIFYING, ALSO
"FOR COLLECTING FOR UTILISATION THE SOLID MATTER IN SUSPENSION IN
SEWAGE ESPECIALLY APPLICABLE FOR OFTAINING PURE POTABLE WATERS."
·
PROVISIONAL SPECIFICATION left by the said James Brough Pow
at the Office of the Commissioners of Patents, with his Petition,
on the 17th October 1871.
I, JAMES BROUGH Pow, of Worcester, do hereby declare the nature
3 of the said Invention for "IMPROVED ARRANGEMENTS FOR FILTERING AND
PURIFYING, ALSO FOR COLLECTING FOR UTILISATION THE SOLID MATTER IN
SUSPENSION IN SEWAGE, ESPECIALLY APPLICABLE FOR OBTAINING PURE POTABLE
WATERS," to be as follows:-
By these improvements I purify water for the use of cities and other
uses, and this Invention is especially adapted for use in towns which lie
low and have little fall; and I.utilize sewage by collecting the solid

page_text: matter in suspension, also chemically precipitating that in solution, so
as to obtain the whole matter contained in the sewage. This plan being
also adapted for the purification of water from the "hush". or minerals
in suspension, or in solution from lead mines, chemical works, tannarics,
or other manufacturing works, so that the water from them may
innocuously pass into any river. The following description sets forth
proper means for carrying the same into practical effect :—
Pits with ascension filters, hereafter described, are erected in duplicate,
triplicate, or in other number, according to the amount of sewage, to
ensuro a frequent charge for the removal of the deposit, which will form
a.most valuable manure. The charges used for the ascension filters may
in degree depend upon the nature of the sewage, and the geological
stratification through which it flows. The separation of matter in
suspension is very easy, but it is much more difficult to arrest and utilize
that which is in solution; therefore the charges of the filters will differ
for sewage, potable water, and for streams containing minerals or
matter from manufacturing works.
As sewage generally contains sulphurettod hydrogen, carbonic acid,
urea phosphates, and nitrogenous constituents, these must be removed
by the material used in the charges of the filters.
It has been stated that London sewage by analysis contains the pro-
portion by weight of chemical matter in solution as three parts to one of
matter mechanically in suspension, and in one hundred tons the value of
the former is 158. 4d., whilst the latter is 28. 2d. It is therefore
proposed that the first filter be charged with aluminum shale from the
lins, and in some cases with one-third chalk, the effects expected is to
precipitate all colouring matter; to take up part of the soda, potass, and
sulphur, and all phosphates, with two-thirds of the nitrogen in any form.
A second filter is charged with spongy iron, this being according to Dr.
Vockler more powerful in its effects than charcoal. Third filter is to be;
charged with cocoa-nut charcoal, firmly consolidated. The materials
except the cocoa-nut charcoal to be granulated or as fine powder.
The Construction of the Filters.-The material or charges for the filters
I pack in boxes of half a ton or upwards, which can casily be put in or
taken out of the filtering case by a portable cranc, when fully saturated:
or renewed a great saving in labour is effected, which cannot be done by
the principle of filtration by descension in the ordinary way. The bottom

page_text: of each filter is composed of strong galvanised wire, supported by cross
diagonal iron bars, the wire covered with a coarse cloth. The top of the
filter is protected in a similar manner, and secured so that the upward
force of the water cannot remove it. The water passes freely through
3 the charges, as can be demonstrated experimentally by a zinc model.
The water after passing the third filter is discharged on to two sets of
iron bars below each other, which break the stream and oxidise the
water before flowing into any river.
In some cases to ensure perfect precipitation it may be needful to put
) a certain quantity of sulphate of iron (copperas) dissolved in water into
the first pit, the cost of which is only trifling, say 38. 9d. to 48. per
hundredweight. The effect produced on gas tar or refuse from gas
works is very apparent when such material forms part of the sewage
when it comes in contact with aluminum shale.
Filtration of Potable Water for Cities.-The proposed Invention for
the better purification of water by the ascension principle for the use of
densely populated towns as a sanatary measure at the present time
demands grave and mature consideration.
The present method of filtration in use by our large water companics
by descension, by merely percolating water through beds of sand and
gravel to a lower level, is attended with great expense without being
thoroughly efficient. This unscientific process simply removes (and
indeed sometimes very partially) the matter in mechanical suspension,
as the turbid liquid dispensed to householders after heavy rains optically
demonstrates, and does not in the slightest degree remove the more
important constituents in solution, generally so prejudicial to the public
health.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Brough Pow in the Great Seal Patent Office
on the 17th April 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, James
BROUGH POW, of Worcester, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of October, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Brough Pow, Her special
licence that I, the said James Brough Pow, my executors, administrators,
and assigns, or such others as I, the said James Brough Pow, 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, excrcise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVED ARRANGE-
MENTS FOR FILTERING AND PURIFYING, ALSO FOR COLLECTING FOR UTILISATION THE
SOLID MATTER IN SUSPENSION IN SEWAGE, ESPECIALLY APPLICABLE FOR OBTAINING
PURE POTABLE WATERS," upon the condition (amongst others) that I,
the said James Brough Pow, 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, tho said James Brough Pow, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement :—
-
My Invention consists, firstly, of improved modes of treating sewage
matter so as to collect and utilize the valuable products contained there-
in, and of purifying the effluent water so that it may be discharged into
rivers without polluting them. I carry out this part of my Invention
by subjecting the sewage matter to a triple treatment, vidolicet, that of

page_text: subsidence, the use of chemical reagents, and filtration by means of my
improved ascension filters; by which means I collect all the solid
matter held in mechanical suspension, and by precipitating the combi-
nations I obtain nearly the whole of the oxidisible material that is found
in chemical solution. And I consolidate the precipitated mass of sewage
matter and dry it on improved kilns, herein-after shewn and described,
and employ it as manure. And I purify the effluent water by subjecting
it to a process of filtration, aëration, and oxidation.
My Invention consists, secondly, of improved modes of purifying
O waters which feed rivers, more especially salmon rivers, by removing
from such tributary streams the particles of poisonous mineral matters
held in suspension or solution technically called "hush," which flow
from lead and copper mines, or impure water ejected by chemical works,
gas works, tanneries, or other manufacturing works, and I carry out this
5 part of my Invention also by the use of my improved ascension filters,
and by the process of aeration and oxidation herein-after described.
My Invention consists, thirdly, of more effectually purifying potable
water intended for consumption in cities and towns, where the water
generally supplied for domestic purposes is very impure, owing to the
O imperfect means of filtration adopted; and I carry out this part of my
Invention by the application of my improved ascension filters, and by
my process of aëration and oxidation.
And my Invention consists, fourthly, of an improved kiln for drying
sewage, and of a mode of excluding rain water from sewers.
And in order that my said Invention may be fully understood, I will
proceed to describe in detail the process and the apparatus I adopt for
carrying out the same, and will refer to the Drawings hereunto annexed,
and firstly with regard to my works for collecting, drying, and utilising
the sewage of cities and towns. I place them in the most convenient
> spot for intercepting or collecting the sewage water, and my arrange-
ment consists of a series of four, five, or any number of tanks or
reservoirs, and which may be erected in duplicate, triplicate, or larger
number of series according to the requirements of the city or town, but
they should all be in communication. The sewage matter after flowing
into the first tank, which should be larger than the others, passes thence
to the second tank through a vertical filter which is charged with

page_text: .
chemical reagents, and then before entering into the second tank it is
thoroughly aërated, and the matters held in solution are oxidised by
three successive falls of the sewage water which enter the second tank
in the form of spray. The fall between each of the tanks should be
from eighteen to twenty-four inches. This treatment is repeated in:
overy tank in succession. The charges of the filters must to some
extent depend upon the nature of the sowage and the soil of the district,
and also upon the purpose to which they are to be applied, whether for
sewage water, potable water, or for streams containing minerals or the
refuse from manufacturing works, since complete oxidation of the :
matters in solution must necessarily take place in every tank, from the
fact that the sewage water not only passes through the filter, but from
being broken into spray an extensive precipitation will also occur, as the
addition of the oxygen of the atmosphere adds to the weight of the
material in solution and consequently tends to precipitate it.
1
When it is required to empty the tanks, which may be necessary once
a week, the sewage water is turned off into the second or duplicato
series of tanks, and the mass in the first tank is allowed to settle for
twelve hours, but in respect to the first tank the sluice between the first
and second tank which is protected by the horizontal filter is opened 2
after a shorter period, and the water is drawn off gradually into the
second compartment, which is eighteen inches or two feet lower than the
first; when the water is reduced two feet in the first the sluice is then
closed, and in this condensed. form the chemicals in solution are added
to assist deodorisation and precipitation, acting upon the natural ?
clements in solution, combining with them and forming an insoluble
soap which is blended in precipitation with the natural deposit of the
materials in suspension. After the specified time the third and fourth
sluices are opened in rotation, the effluent water slowly flowing into the
river perfectly innocuous. The chief deposit remains in the first tank, 3
which after a proper time allowed for drainage is in due course removed
to the drying kilns, there further deodorised and rendered fit for removal
to the depôt or by the contractor.
I will now proceed to describe the construction of the filters.

page_text: which the sewage water falls from the filter into the pit and becomes
acrated.
Figure 8 shows a double row of filtering boxes, seven in each row,
cach box 3 feet + 4 feet and 4 feet deep.
B, E, D, F, is the front appendage over which the water flows from
the filters and then falls upon the second shelf a, b, c, d, placed two
inches below the first, from which the water is projected from each side
on to the rows of iron bars which form the fall of spray into the next
tank; A, B, C, D, is over the first tank, and B, E, D, F, projects over
the second. Each tank in succession is twenty-four inches below the
other to give space for the flow of spray. Therefore in using four tanks
the water passes through sixteen feet of depth of filtering material.
The construction of the filters is as follows:-Each filter consists of
one or more boxes which may be increased or extended according to the
amount of sewage. Each box is a filter in itself; it consists of four
sides of galvanised iron, the bottom being made of strong galvanised
iron wire supported by diagonal iron bars; the interior is covered with
coarse cloth, matting, or bagging, which should be of sufficient length
to come partly up the sides, the better to effect the emptying of the
> charge. The charge may be placed in three or four layers, each
protected by a cloth between. To afford fine filtration the best and
finest pounded material is placed next to the bottom. The charges are
packed as closely and as solidly as practicable. The top of the filter is
protected and secured, being of fine and coarse galvanised wire, with a
cloth or matting between so that the upward force of the water, which is
very considerable, cannot remove it. The sewage water passes freely
upwards through the chemical charges however solidly packed, the
materials of which are only partially soluble yet having affinity with
the matter in solution; what is removed is again restored by a replacing
material. The water is then projected from a semicircular plate in front
of the filter upon two sets of iron bars, and descends into the second tank
as a fountain of spray, and in a similar manner through the succeeding
filters and tanks. The boxes forming the filter are intended to be each
two feet in length, three or four feet wide, and three or four feet in
depth placed against each other, and may be lifted out and renewed
when saturated with the matter in solution by a portable crane. The
passage of the sewage through the filters may be regulated by the
quantity and may be made to occupy a considerable time when neces-

page_text: •
mode of getting rid of 5
sary, say from five to ten times the duration of time the sewage occupies
in flowing from the main sewer into the tank. Provision should be
made in the main sewer to confine the water which enters the tanks to
sewage water only, to the exclusion of rain water as far as may be
practicable, and I describe herein-after a
storm water so as not unnecessarily to dilute the sewage. In reference
to the deposit from the tanks the largest amount being in the first, I
erect drying kilns herein-after described at the top or side of the first
tank raised above the quay three or four feet; the deposit is then to
be raised by a lift on to a tramway eight feet or so above the quay 1
and from thence run into the drying works. The deposit may be raised
in tubs by the aid of geers or drops similar to those used for putting
coals into ships' holds in the "Tyne" and "Wear" rivers. The trucks
are then run into the drying house at once and emptied upon the stove,
where it is turned over by mechanical means, and when thoroughly dried 1
and reduced to powder sent off to the depôt or to the contractor.
The machinery for raising the drops or geers may be worked by
steam power or compressed air, and the haulage carried on in the same
manner.
I would here remark that the sewage matter in a fresh state is not 2
offensivo in odour; it may be partially deodorised when in a liquid state
in the pits, and be thoroughly deodorised in the kilns; and the water
flowing from it returned, not to the pit where the sewage came from, but
to the adjacent pit or duplicate then working.
.
The charges I use in my improved ascension filters must depend to 2
some extent upon the nature of the sewage, and the stratification of the
soil through which it passes and to the object to be effected, that is to say,
whether it is desired to purify sewage water or to more effectually filter
potable water, or to purify streams polluted by mineral admixture, or
the refuse from factories or works.
Sewage water generally contains sulphuretted hydrogen, carbonic
acid, urea phosphates, and nitrogenous constituents; these must be
removed by the chemical affinity of the material used in the charges
of the filters.
3
It is generally believed that London sewage contains the proportion by 3
weight of chemical matter in solution of three parts to one part of
matter held in mechanical suspension, and that in one hundred tons of

page_text: a ventilator capable of being closed.
The entire building to be closed in and easily ventilated.
After the sewage is deposited upon the kiln the fires are to be lighted,
coke to be used instead of coal; the heated air will range from 70
to 90″ Fahr. and the evaporation will commence. I then introduce
through small apertures as the means of deodorising the material
basins containing four pounds of common salt, into which is poured
a pint of sulphuric acid; a red hot heater is then dropped into the
basin and the aperture closed. This quantity will generate sufficient
chlorine gas to disinfect 1,000 cubical yards of air, and can be repeated
in number according to the size of the kiln. The gas generated is
two and a half times heavier than atmospheric air, and will speedily
decompose and dissipate the bad odour and deodorise the sewage
matter. The ventilator when opened will throw off the deodorised air
having a smell of seaweed. After a sufficient time has clapsed which
experience will dictate, the doors of the kiln can be gradually opened
and the air admitted; an arrangement can be made at all times for the
evolution of this gas to a moderate extent to keep the buildings sweet
and free from all offensive smells.
The buildings must be constructed of wood, brick, or stone, without.
any iron or metal work, on account of the nature of the gas.
.
Figure 5 represents a section of the fire-places for the drying kiln ;
O, C, C, the general fluo six to eight inches wide by three or four fect
in height, perforated with holes, to allow of the dispersion of the hot
air. E represents the chimney (if one be needed), but if good coke be
used there is little or no smoke; a fall from A to B on the floor of tho
kiln and a floor from B to C for the better drainage of water thrown off
by the sewage. a, a, a, an open space at the end of each fire which
will admit the heated air which must pass under the fires; b, b, the
flues, six inches deep by four feet wide, may be divided by intermitting
bricks to rest the tiles of the floor, and will produce a great draught.
Figures 6 and 7 show my improved plan of confining sewage water in
the sewage, to the exclusion of rain water. Figure 6 is the ordinary
sewer, the basin is supposed to be sufficient for all the ordinary sewage

page_text: water, from the crown of the arch to the dotted line is intended to be
filled up with brickwork, at all events it may be built up from a to b;
when the water rises to a then the storm water sewer No. 7 comes into
operation. The object as far as possible is to confine the sewer for
sewage water only. Figure 7 is the same in perspective. It does not
necessarily follow that the sewers are to diverge; they may run parallel
to each other, the storm water sewer direct to the river.
Having now described my process as applied to sewage matter, I will
proceed to describe its application to the purification of tributary
streams, and for the purification of potable water:-It is well known
that in many rivers salmon might be profitably reared were they not
polluted by the waters which flow from mines, and by the refuse from
manufactorics and chemical works, and that in many smaller towns the
expense of collecting and of attempting to utilise sewage costs more
than the returns obtained from the products.
By the use of my improved ascension filters, which may be constructed
on a small scale, firstly, the water which feeds rivers may be thoroughly
purified by simply causing it to pass through the filters at the head of
the river or at the sources of supply, and when requisite by charging the
filters with materials adapted for the absorption of "hush" or mineral
matter in suspension or solution, and when the object in minor towns is to
get rid of the sewage at a small cost, the use of my filters will enable the
local boards to purify the sewage water, which may then be permitted
to flow into rivers or canals without detriment to the health of the
surrounding population.
When water charged with lead in solution from mines is desired to be
purified, I charge my filters with pulverised iron pyrites (bi-sulphide of
iron) combined with vegetablo charcoal and formed into compressed
cubes or half cubes in half cubes when there are three or more layers,
each layer overlapping the joints of the other.
When it is intended to filter water charged with copper, I employ a
chargo or charges of bright steel or iron filings profusely mixed with
charcoal and formed into compressed cubes.
The adoption of my principle for the better purification of water
intended for domestic purposes will be a great improvement upon the
present method of filtration by percolation through sand beds and
gravel as commonly practised by the water companies of large cities.

page_text: The present process is capable only of removing the matters held in
.machanical suspension, and that very imperfectly, and cannot eliminate
the more dangerous elements held in solution.
By my principle the water is oxidised by aëration, and is further
purified by passing through the carbonised charges of the filters by 5
which the phosphates are removed with all other prejudicial constituents,
and by which means the generation of fungi so common in polluted
water is entirely prevented.
Having now particularly described and ascertained the nature of my
said Invention and how the same is to be carried into effect, I wish it to 1
be understood that I make no claim to the principle of ascension filters
in general, but what I do claim and desire to secure by theso Letters
Patent is,--
Firstly. The peculiar construction and arrangement of the ascension
filters herein-before described and shown.
Secondly. I claim the mode of aërating water herein-before described
and shown for purifying sewage and other water.
Thirdly. I claim the construction and arrangement of kilns for drying
sewage as herein-before described and shown.
And, lastly, I claim the arrangements for confining sewage water in 2
the sewer hercin-before set forth.
In witness whereof, I, the said James Brough Pow, have hereunto
set my hand and seal, this Thirteenth day of April, One thou-
sand eight hundred and seventy-two.