VARIOUS IMPROVEMENTS IN THE CONSTRUCTION OF AN APPARATUS FOR THE PURIFYING OF LIQUIDS
Year: 1818

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN SUTHER-
LAND, of Liverpool, in the County of Lancaster, and also of Number Ninety-
nine, Houndsditch, in the City of London, Coppersmith, send greeting.
WHEREAS His most Excellent Majesty King George the Third, did, by
5 His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Seventh day of March, in the fifty-eighth year of His said
Majesty's reign, give and grant unto me, the said John Sutherland, my exors,
admors, and assigns, especial licence, full power, sole privilege and authority,
that I, the said John Sutherland, my exors, adiñors, and assigns, and every
of them, by myself and themselves, or by my and their deputy or deputies,
servants, or agents, or such others as I, the said John Sutherland, my exors,
admors, or assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend my Invention therein
mentioned, [of "VARIOUS IMPROVEMENTS IN THE CONSTRUCTION OF AN APPARATUS
FOR THE PURIFYING OF LIQUIDS,"] within that part of the United Kingdom of
Great Britain and Ireland called England, and the Dominion of Wales, and
Town of Berwick-upon-Tweed, and also in all His said Majesty's Colonies and
Plantations abroad; in which said Letters Patent is contained a proviso, that
if I, the said John Sutherland, should not particularly describe and ascertain
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, and cause the

page_text: same to be inrolled in His Majesty's High Court of Chancery within two calen-
dar months next immediately after the date of the said Letters Patent, that
then the said Letters Patent, and all liberties and advantages whatsoever
thereby granted, should utterly cease, determine, and become void, as in and by
the same Letters Patent, relation being thereunto had, will more fully appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Sutherland, do hereby declare that the nature of my said Invention, and
the manner of carrying it into effect, are particularly described and ascertained
in and by the Drawings hereunto annexed, and the following description
thereof, that is to say :-
In many of the arts it becomes necessary to effect a separation of very
minute floating particles of insoluble matter from the liquids in which they
are suspended, and for its accomplishment the principle of filtration under a
variety of forms has generally been resorted to. The disadvantages which
attend the apparatus for filtration now in use, are either the smallness of the
surface exposed to the action of the liquid, or when that surface has been
enlarged, that any injury arising to the smallest part of it and occasioning a
foulness in the runnings, this foul liquor cannot be separated from that which
is purified, and consequently the whole of that operation is destroyed.
My improvement consists in the invention of an apparatus which exposes to
the action of the liquid a filtering surface of great extent contained in a small
space, and so arranged that in case of any accident accuring to one or more
parts of it and producing impure runnings, a stop can be put to the filtration
of that part of the surface whilst all the rest continues in action, and the
general operation of the filter is in no way impeded or its product rendered
impure. My filter consists in a square oblong box or case of cast or wrought
iron, copper, wood, or other material suitable to the nature of the liquid to be
operated upon. In the centre of the bottom of this box a brass plate, about
six inches broad and two inches thick, extends from one end to the other.
This brass plate is perforated by a row of conical holes in its centre, running
from one end to the other, and at the distance of about an inch from one
another. These holes are all ground, so as to be water-tight, with a plug or
stopper of the same size, and they perforate the bottom of the filter, and to
each separately there is a tube connected, which is terminated by a stop-cock,
so that they are independent of each other on the outside of the box or case.
The filtering surface consists of linen, cotton, or woollen cloth, stretched upon
both sides of a frame, as will hereafter be described, and these frames have
each at their bottom a hollow plug, which opens into the interior of the frame
between the folds of cloth, and fits with its outside into the conical holes in the
5

page_text: brass plate already described. There are as many frames of this description
for one filter as there are holes in the plate, and when the apparatus is to be
set to work, they are separately placed in an upright position parallel to each
other, and likewise to the ends of the box or case, with their plugs in the
holes: The liquid to be purified is then introduced into the filter, and when it
is full, the frames or leaves will be wholly covered, and the liquid having no
passage outwards but through the interior of the leaves, will rapidly pass
through the cloth, depositing all its mechanical impurities thereon, and escape
by the hollow plug, tube, and stop-cock.
This is a general description of my improvement in the apparatus for puri-
fying liquids; but that in order that its construction and the manner of working
it may be more fully understood, I have hereunto annexed Drawings thereof,
and the following references thereto.
Figure I. is a cross section of the filter. A, A, A, is the outer box or case,
which widens at its mouth B, B, for the purpose of presenting a bearing for
the cover C to rest upon. The cover is held down by several bars of iron, one
of which is D, and which are fastened by moveable keys as at E, E. Through
this bar the screws F, F, work, and press the cover C upon the bearing B, 'B;
G, G, is one of the filtering frames or leaves, which are covered with cloth;
H is the hollow plug, which fits into the conical socket I, and discharges
through it by the tube and stop-cock K and L; M is a stop-cock and
pipe communicating with the vessel in which the liquor to be filtered is
contained. This vessel must be on a higher level than the filter, in order
to obtain a pressure from a column of liquid, but no precise height can
be given, as it must vary with the greater or less viscidity of the liquor to be
purified. When the last of the liquor has descended into the filter, a portion
will remain in it in consequence of having no hydrostatick pressure to force it
through the cloth; in order to accomplish the filtration of this latter part, a
small air pump N is attached to the cestern or filter, and when the filtration
becomes languid for the reason already assigned, the supply cock M is shut,
and this force pump is worked, in order to throw in a quantity of air, which
keeps up a constant pressure and completes the opperation. O is a stop-cock
for running off any quantity of liquid that may remain below the bottom of the
leaves; P is a small funnel with a stop-cock attached to it, passing through
the cover; Qis a screw which passes through the cover, and has a bar
attached to it, which presses upon the leaves and keeps them firm in their
sockets. Figure II. is a longitudinal section of the filter; A, A, A, is the
outer box or case; B, B, the bearing upon which the cover C rests; D, D, D,
the bars of iron, fastened by keys to the filter; F, F, F; screws working

page_text: through the bars D, D, D, and which fastens down the cover C; G, G, G,
sections of the filtering frames or leaves, which are covered with cloth; H, H,
the hollow plug which convoys out of the filter the purified liquid which has
passed through the cloth. into the interior of the leaf: I, the conical sockets
into which the plugs fit, and to which the tubes and stop-cocks are attached;
Q, Q, are screws which work through the cover C, and have attached to them
a bar of metal or wood about two inches broad and the length of the interior
of the filter; R is a piece of metal or wood in the shape of a comb, between
the teeth of which the filtering leaves are placed for the purpose of keeping
them asunder. The frame upon which the filtering cloth is stretched is made
about two inches less than the internal size of the filter. and about half an inch
thick. I first make a skeleton the full size of the frame upon which I stretch
across and rivett bars of copper, in order to keep the cloth from coming in
contact when the pressure of the liquid comes upon them; but the form and
manner of constructing the frame may be varied according to circumstances;
and the quality and thickness of the cloth must also vary according to the
nature of the liquid to be filtered, but for most purposes I prefer such as is
known by the name of Russia duck. In order to cover the frame I form the
cloth into a bag as near as possible the size of the frame. I then draw the
bag upon it making a hole for the plug and sew up the open end and round
the plug. The leaf is then ready for the operation. When the filter is to bo
prepared for working, all the stop-cocks are to be shut and the leaves or
filtering frames G placed in their sockets I. The bars R, of which there are
two, are then placed with their teeth between each leaf, one on each side of
the filter. The cover C is then placed upon its bearing B; upon this bearing
there is placed a stuffing of leather, hemp, or woollen, in order to make a tight
joint. The bars D are then fastened by their keys E, and the screws F
brought home upon the cover. The screws Q are then turned until the bars
attached to the inside of the filter presses upon the tops of the leaves and keeps
them steady in their sockets. The stop-cock of the funnel P is then opened,
and afterwards the supply cock M. The liquor to be filtered will then rush
in and force the air out through P, and when the liquor appears in the funnel
the stop-cock is to be shut. The small stop-cocks L are then to be all opened,
through which the filtered liquor will pass and may be conducted into any
proper vessel.
In some cases the first which runs will not be perfectly
purified, but the larger pores of the cloth will speedily close up and obstruct
the passage of every floating particle. When this foul running occurs it may
be collected in a separate vessel and again filtered. In this apparatus I do
not claim as my Invention all the different parts of it taken separately, neither

page_text: do I claim any exclusive privilege of the application of the pressure of a
column of liquid in the operation of filtering. My Invention consists in the
method of placing the leaves in the ground sockets and of carrying off the
purified liquor therefore by means of separate pipes and stop-cocks, so that
each leaf becomes a distinct filter, and may be worked singly or altogether, so
that any accident occasioning foul runnings from one will in no ways impede
the action of the rest, as the operation of the foul leaf may be put an end to
by shutting its stop-cock.
In witness whereof, I, the said John Sutherland, have hereunto set my
hand and seal, this First day of May, in the year of our Lord One
thousand eight hundred and eighteen.