IMPROVE- MENTS IN FILTERING WATER, AND IN APPARATUS FOR THE SAME
Year: 1858

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent, for the Invention of "IMPROVE-
MENTS IN FILTERING WATER, AND IN APPARATUS FOR THE SAME."-A com-
munication.
Sealed the 9th August 1858, and dated the 19th February 1858.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 19th
February 1858.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN FILTERING WATER, AND IN APPARATUS FOR THE
SAME," to be as follows:-
This Invention relates to filtering water rapidly. by means of pressure
exerted by a force pump or other suitable mechanical means, or by a head
of water of sufficient height to give the pressure required to force the water
up through the filtering vessel or vessels and materials.
For this purpose I employ cylinders or vessels containing a quantity of fine
sand, which is placed between two perforated diaphragms or partitions, the
lower one fixed and having below it a space to receive the water to be filtered,
the upper one moveable and furnished with a screw by which it can be forced
downwards for the purpose of compressing the sand; a capacity also remains
above it for the filtered water. I connect two, three, or more of these vessels

page_text: together by pipes furnished with stop-cocks which lead the water from the
upper part of the first vessel to the lower part of the next, and so on, through
the series. The water is admitted at the bottom of the first vessel, passes up
through the filtering material to the upper space, and descends thence by its
pipe of communication to the lower cavity of the next vessel in succession, and
so on. When filtering, the sand is placed under pressure. When it is desired
to wash the sand, it is relieved from the pressure and channels of communica-
tion opened between the upper cavities of each vessel and the supply of water
under pressure, as also of channels of escape from the bottom of each vessel.
The pipes of communication between the vessels before mentioned are at the
same time stopped; the inlet pipe for filtering is also stopped. The result is
that the water runs freely through the vessels from top to bottom, passing
through the sand, and so cleaning it thoroughly. To filter again it is simply
necessary to compress the sand and establish the proper communications
for the purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Clark in the Great Seal Patent Office on
the 18th August 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
"Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of February,in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Clark, Her special licence that I, the said William Clark, my
executors, administrators, and assigns, or such others as I, the said William
Clark, 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 FILTERING
WATER, AND IN APPARATUS FOR THE SAME," (a communication), upon the
condition (amongst others) that I, the said William Clark, 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

page_text: 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 William Clark, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Sheet of Drawings hereunto annexed,
and to the letters and figures marked thereon, that is to say:-
This Invention relates to a continuous pressure filter for filtering a large
quantity of water very rapidly (the filter being of but small size) by means
of pressure obtained either from a lift and force pump or from a reservoir
having a sufficient head of water.
The filtering material in this apparatus consists only of very fine sand,
which is compressed in each filtering cylinder or chamber by means of
diaphragins which may be raised or lowered at will, thus replacing with
advantage the porous stone hitherto employed for filtering purposes, the sand
having none of the inconveniences attending the stone, as the salts of lime do
not adhere to it and form a solid body, as they do with porous stones.
In the Drawings annexed I have represented an apparatus for filtering
about 220 gallons in 24 hours. Figure 1 shows an elevation of an apparatus
consisting of three filtering cylinders; Fig. 2'shows a partial plan of the same;
Fig. 3 shows a plan of one of the filtering cylinders, with the cover removed;
Fig. 4 shows a transverse vertical section, and an elevation of a similar
apparatus modified. The same letters indicate like parts where they recur in
all the Figures. a, supply pipe of the water to be filtered; b, stop-cock on the
pipe a, affording passage to the water into the first filtering cylinder; c, second
stop-cock forthead mission of the water to be filtered into the second cylinder;
d, third stop-cock for the passage of the water into the third cylinder; e, first
filtering cylinder of cast iron, containing the sand which is to be substituted for
the filtering stone; f; second filtering cylinder, precisely the same as cylinder e;
9, third filtering cylinder, placed next to the two others and worked in the same
manner; h., diaphragms placed in the interior of each cylinder, the upper
one of which is caused to approach the lower one by means of a screw, and by
his means effect pressure on the sand placed between them; these diaphragms
are pierced with holes throughout their area for the passage of the water to be
iltered. ., pressure screw fixed to the upper diaphragm, serving to force it
owards or withdraw it from the lower diaphragm; j,gland forming a nut for
crew i, placed in the centre of the cover of each cylinder; k, cock for the

page_text: passage of the water which has been used to cleanse the sand, for which
purpose it is placed at the bottom of each cylinder e, f, g; l, very fine sand,
compressed and placed between diaphragms h, h; m, outlook cock for the
filtered water, which may be conducted to any suitable receptacle; n, tube to
convey water directly to cylinders e, f, g, to either separately, or to the whole
number; 0, 0, stop-cocks placed on tuben for regulating the passage of the
water into each cylinder e, f, g; p, lift and force pump, serving to cleanse
the sand in case the water be filtered is very dirty and contains much
extraneous matter.
The action of this apparatus is easily understood; for instance, if the whole
is mounted as illustrated in the Drawings, it will be seen that the water
arriving in the cylinders e, f, g, through the cocks b, c, and d is forced (by the
pressure exerted on it by the lift and force pump, which draws it from a
reservoir of large dimensions,) to traverse the fine sand contained between the
diaphragms h, h, at a certain speed, and when filtered to escape by cock m,
from which it is conducted as required. The cleansing of the sand may be
effected daily and in a few minutes without displacing any part of the
apparatus; it suffices to unscrew the upper diaphragm h of such cylinder by
means of screw i, then close to the cocks 6 and m, and to open cocks c and d,
as also cocks k, k, k. The water, instead of entering at cock b, will enter the
upper part of each of the cylinders by the cocks 0, 0, 'and pass through the
sand, which is no longer compressed, and completely cleanses it, thence it
escapes by cocks h, k, k. When the cleansing is effected, the cocks o are
closed and the cocks band m opened, the water then rises from beneath,
is filtered, and passes out by the cock m; thus it will be seen that the
filtering is effected by the water entering the lower part, and the cleansing
by the water entering the upper part of the cylinders.
.
The apparatus represented at Fig. 4 is a modification of the foregoing.
a, filtering cylinder; 61, shaft carrying the moveable diaphragın, having a
screw thread at its upper part for adjusting it; c',irou prongs fitted to shaft b';
operating on the layers of sand during the cleansing; d¹, brass nut, forming a
stuffing box at the upper end of shaft b', serving to raise and lower shaft 6,
and consequently the lower diaphragm to which it is connected; e', hand wheel
placed on shaft b'; f', f, diaphragms, the upper one of which is fixed, the
lower one being fitted to shaft b' partakes of its motion. These diaphragms are
placed in cylinder a¹ and embrace between them the sand for filtering; they
have small perforations throughout their surfaces for the passage of the water.
g', small steam engine for working the lift and force pump which supplies the
water to be filtered to cylinders a¹; h', air receiver placed between the force

page_text: pump and the pipe conducting the water to the cylinders for the purpose of
insuring a continuous supply. The action of this apparatus, as also the
cleansing, are the same as for the first apparatus.
Having described the nature of this Invention, and the manner of per-
forming the same, I declare that what I claim as the Invention to be
secured by the berein-before in part recited Letters Patent is,-
First, a continuous filter, arranged and acting by means of pressure, as
herein-before described; also the modification of the same represented
at Fig. 4.
Secondly, the application to filters of fine sand in a compressed state as
a substitute for the porous stone hitherto used.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Eighteenth day of August, in the year of our
Lord One thousand eight hundred and fifty-eight.
W. CLARK. (L.S.)