IMPROVE- MENTS IN FILTERING WATER AND OTHER LIQUIDS
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
FORSTER, of Liverpool, Merchant, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-seventh
day of June (One thousand eight hundred and fifty), in the fourteenth
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said James Forster, my exors, adiñors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said James Forster,
my exors, adiňors, and assigns, or such others as I, the said James Forster,
my exors, admors, or assigns, should at any time agree with, and no others,
from time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "IMPROVE-
MENTS IN FILTERING WATER AND OTHER LIQUIDS;" in which said Letters Patent
is contained a proviso that I, the said James Forster, shall cause a particular
description of the nature of my said Invention, and in what manner the same
is to be performed, by an instrument in writing under my hand and seal, to
be inrolled in Her Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited
Letters Patent, as in and by the same, reference being thereunto had, will
more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Forster, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had to
the Drawing hereunto annexed, and to the figures and letters marked thereon, 5
that is to say
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Forster, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof; reference being had to
the Drawing hereunto annexed, and to the figures and letters marked thereon,
that is to say
My Invention consists,―
First, of improvements in apparatus used for filtering water and other
liquids; and,
Secondly, my Invention consists of cleansing filters by chemical means.
And in order that my Invention may be most fully understood and readily
carried into effect, I will proceed to describe the means pursued by me.
DESCRIPTION OF THE DRAWING.
The Drawing Fig. 1 shows a section, Fig. 2 a plan, Fig. 3 a side elevation,
and Fig. 4 an under side view of apparatus constructed according to my
Invention. a is the filtering vessel, which I prefer should be composed of
filter stone, but other porous matters made into the form of a hollow vessel,
and suitable for filtering according to my Invention, may be employed, and I
believe the spherical form to be the best for this vessel, but I do not confine
myself thereto. 6 is an external vessel or jacket, which is to be of such
strength and form as to sustain the pressure of the water or other fluid
supplied from a main, or by a force pump at c, and the water or other fluid
is forced into the vessel a, and through the outlet d; and it is to be understood
that the filtering and delivery of the water or liquid depends on the force or
pressure of the fluid, there being no passage or pipe for admitting air into
porous vessel a. In making the vessel a of filter stone, I cause it to be
made or cut in two or more parts, and I cement them together as shewn, and
for the outlet I use an earthenware or metallic or other junction d, as shewn.
e is a cock or tap communicating with the jacket or outer vessel. This serves
the purpose of cleansing the space between the outer and inner vessel, and
also for drawing unfiltered water, when required.
the
I would remark that I am aware that filtering vessels have before been
made of stone and other porous matters, and placed in cisterns or other open
vessels, the water flowing from the porous vessel by reason of the use of
suitable air pipes or passages.
I do not therefore claim the same, this part
of my Invention consisting of the mode herein described of combining a porous
vessel a with a closed vessel b, and suitable taps or outlets, as described, so
that the filtration and discharge of the water or other liquid shall be by the

page_text: pressure of the fluid, as explained. I would state that although I have
described my Invention as using only one porous vessel a within another close
and strong vessel 6, when for waterworks I recommend several such vessels a
within one such vessel b.
I will now describe the second part of my Invention, which consists of a
chemical method of cleansing or purifying the filtering material through which
the water or other fluid is made to pass. The removal of solid or insoluble
impurities being the object sought to be gained by all processes of filtration, it
therefore becomes necessary from to time to have means of removing them,
not only from the surface of the filtering stone, whether it be artificial or
natural, but also when such have penetrated beyond its surface. To effectuate
this purpose I adopt the following means, which vary with the circumstances,
and with the nature of the impurities to be got rid of:-First, should the
pores of the filter become stopped during the process of filtration by aluminous
or clayey matter, it (the filter) is to be unfastened from its outward casing,
and then immersed in a boiling solution of dilute sulphuric acid, containing a
small proportion of nitrate of potassa. After remaining so immersed for a
period varying from fivo to fifteen minutes, it is to be removed, and the
aluminous matter there formed, together with the free acid, may be readily
washed from the stone by passing water through it. In this process I prefer
to use a solution of the following strength, namely, two fluid ounces of sulphuric
acid to one pint of water, in which is dissolved one quarter of an ounce of
nitrate of potash. Second, should the filter become obstructed by lime, or its
carbonate in the state of chalk, in order to remove either of these substances I
prefer to use a dilute solution of hydrochloric acid in the manner above
stated, that is to say, by the immersion of the filter, but in this case it is un-
necessary to raise the dilute acid beyond the ordinary temperature. By this
treatment the lime or chalk, being soluble in this acid, is easily removed from
the interior of the filter by washing, the strength of the solution to be in the
proportion of two fluid ounces of acid to one pint of water. Third, should
the porosity of the filter become obstructed by oxide or carbonate of iron, these
substances may be dissolved in like manner by dilute muriatic acid in com-
bination with a similar quantity of water, and at the ordinary temperature.
The resulting chloride of iron is then easily got rid of by passing water through
the filter. Fourth, should the porosity of the filter become obstructed by an
oxide of lead, in order to cleanse it of this substance the filter is to be
immersed in a hot or boiling solution of dilute nitric acid, there to remain for
a short period, varying from ten to fifteen minutes, after which the resulting
nitrate of lead may be cleansed from the filter by washing in water. In this

page_text: instance I prefer to have the strength of the acidulated solution in the pro-
portion of three fluid ounces of nitrate acid to one pint of water. Fifth, when
the pores of the filter become obstructed by carbonaceotis or peaty matter,
such are to be dissolved by the application of concentrated sulphuric acid,
raised a little above the common temperature, to facilitate the solubility of the
carbonaceeus matter, after which treatment the dissolved carbon may be
removed from the filter by boiling water. Sixth, should the filter become
obstructed by the refuse or more solid impurities of oily or fatty matter, they
are to be removed by a hot alkaline solution, consisting of either soda or
potash, in which it is well known such substances become saponaceous, and in
consequence are easily removed by hot water.
With regard to the above methods of cleansing by chemical agency, I wish
it to be distinctly understood that I do not confine myself thereto, as I am
aware that there are other acids and alkaline substances which are capable of
effectuating the same objects as are here named, but there are none, I believe,
at present known to chemists which may be applied so cheaply and effectually
as those which I have pointed out. What I claim is the application of
chemical bodies, which act, while in solution, of solvents of those solid impu-
rities which obstruct the action of filters.
In witness whereof, I, the said James Forster, have hereunto set my
hand and seal, this Twenty-seventh day of December, in the year of
our Lord One thousand eight hundred and fifty.
AND BE IT REMEMBERED, that on the Twenty-seventh day of December,
in the year of our Lord 1850, the aforesaid James Forster came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Enrolled the Twenty-seventh day of December, in the year of our Lord
One thousand eight hundred and fifty.