IMPROVEMENTS IN THE PURI- FICATION OF LIQUIDS, THE SEPARATION FROM THEM OF MATTERS HELD IN SOLUTION OR SUSPENSION, THE RECOVERY OF THESE AND OTHER BYE PRODUCTS OF MANUFAC- TURES, THE APPLICATION OF THE AGENTS THERETO, AND THE MEANS AND APPARATUS EMPLOYED THEREFOR
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by John Foulis and James Anderson
Carrick at the Office of the Commissioners of Patents on the 5th January
1878.
JOHN FOULIS, of Musselburgh, and JAMES ANDERSON CARRICK, of Edinburgh,
both in the County of Mid Lothian, North Britain. "IMPROVEMENTS IN THE PURI-
FICATION OF LIQUIDS, THE SEPARATION FROM THEM OF MATTERS HELD IN SOLUTION
OR SUSPENSION, THE RECOVERY OF THESE AND OTHER BYE PRODUCTS OF MANUFAC-
TURES, THE APPLICATION OF THE AGENTS THERETO, AND THE MEANS AND APPARATUS
EMPLOYED THEREFOR
"
This Invention has the following for its objects:-
Firstly. The purification of the effluent waters of paper mills and similar works
by the separation therefrom of matters held or contained therein, technically termed
sludge.
Secondly. The recovery of such sludge, and the application of other bye products,
such as waste bleach, and waste "soda limes," resulting from such manufactures in
admixture with water, either singly or combined, to the purification of the effluent
waters of mines, mineral oil, dye, skin, tan, glue, gelatine, and other such works,
whereby acids, acid salts, decayed animal or vegetable matter, or other deleterious
substances are separated from the said waters.
Thirdly. To provide means or apparatus to effect the separation or filtration of
liquids from solids or semi-solids, either as auxiliary to the processes aforementioned,
or as distinct, and either as applied for the recovery of secondary products as con-
tained in the effluent waters of manufactures, or for primary articles of manufacture,
such as cement, clay, starch, and others as herein-after referred to.
For the purification of waste waters, the following process or method is employed,
which is more especially applicable to the treatment of the waste waters of paper mills.
There is added to the said waters, from one quarter per cent. to one per cent. of a
solution of sulphate or chloride of zinc, or a mixture of these obtained by dissolving
metallic or other suitable compound of zinc in sulphuric or hydrochloric acids,
singly or combined, or the said solution may be obtained as a waste or bye-product
from various manufactures, and containing either or both of these salts. The effect

page_text: of these solutions is to neutralize or render all or the greater portion of the injurious
or deleterious matters in the water insoluble, and after an interval of time, varying
with the nature of the said matters, there is added from one quarter per cent. to
one per cent. of a solution of caustic or carbonated soda or other alkali or alkaline
earth, which precipitates the matters held in or by the water, at the particular
stage of manufacture at which the addition of the aforesaid solutions is made.
The second solution may also be a waste or bye-product of various manufactures,
such as waste bleach and "soda limes," or a mixture of these, or they may be used in
a semi-solid state. The proportions of both solutions added to the water to be
purified vary in accordance with the requirements from one quarter per cent. to
one per cent., being approximate proportions for ordinary cases.
In the purification of the effluent water of mills, where brown and other of the
coarser descriptions of paper are made; the admixture of the solutions with the
water may be effected during the breaking or washing operations, preferably about
one hour after "furnishing," an interval of approximately from ten to twenty minutes
being allowed to elapse between the addition of the two solutions, and should the
water not be sufficiently purified after the lapse of approximately ten to twenty
minutes, further quantities of the solutions as are necessary to produce the desired
effect are added in the same manner and order. The chemicals employed do not
injure the machinery, materials, or finished products of the mills.
In mills where the finer descriptions of paper are made, the process of purification
is similar as to quantity and time, but the admixture of the solutions with the
water is preferably made after the washing operation is complete.
وو
If desired, a small per-centage of the solutions may also be added in the stuff
chest, sand trap, or knotters, as also in the outflow drain of the mills, or in depositing
tanks or settling ponds, in which latter the " sludge is precipitated and re-used
in manufacture. The effluent or superposed water is thus freed from its impurities.
To purify the effluent waters of mines, mineral oil, dye, skin, tan, glue, gelatine,
and other such works, the issuing waters from which are more or less charged with
impurities, there is added thereto and agitated therewith a proportion of waste
bleach and "soda lime," either singly or combined, and brought with water to
about the consistency of a cream. When the admixture of the said cream and
impure water is complete precipitation ensues, but should the water not be suffi-
ciently purified, a requisite proportion of the aforementioned solution of sulphate or
chloride of zinc is added thereto, until the desired result is produced.
The order herein-before set forth of admixture of the solutions or chemicals
with the water to be purified, may be reversed, as from the nature of the matters
therein such alternative process may be necessary to purification, and the purifying
processes are carried on uninterruptedly.
The means and apparatus employed to effect the separation or filtration of liquids,
from primary or secondary solids or semi-solids of manufacture, consist of a tank,
reservoir, pond, or other receptacle or vessel which is divided at any desired and
convenient depth by a false bottom or diaphragm into an upper and under com-
partment. The false bottom or division is formed of any suitable perforated
material, and may or may not have an additional covering of cloth, matting, wire-
web, or other porus substance capable of transmitting water or other liquid, but
intercepting solid matter. The under compartment of the receptacle or vessel is
filled with water by means of a supply pipe opening into it. The cock of the said
supply pipe being closed, the upper chamber or compartment receives the liquid,
solid or semi-solid, to be operated upon. On the first stroke of a pump connected
to the bottom of the lower compartment, a certain quantity of the water in the
latter is withdrawn, whereby a vacuum is formed therein.
The atmospheric pressure exerted on the contents of the upper compartment or
chamber forces the liquid portion of the said contents through the false bottom or
diaphragm into the lower chamber, whence it is withdrawn by the pump, and the
vacuum maintained.
The solid matters remain in the upper compartment or chamber, whence they are

page_text: readily removed as required, and the upper compartment again charged. In the
event of the vacuum becoming lessened or destroyed, it is restored by ceasing the
pumping action, refilling the lower compartment of the receptacle from the supply-
pipe before mentioned, and proceeding as aforesaid.
By these means liquids may be separated from solids, as an auxiliary process in
the purification of the former, or as distinct therefrom either as applied to the
secondary products of manufacture such as "sludge," or to primary products as in
cement, starch, clay, sugar, and other works where filtration is necessary or desirable,
and the quantity dealt with at one time may be large or small, according to the
capacity of the reservoir, tank, or other vessel.
The pressure on the contents of the upper compartment of the receptacle may be
augmented in any way which may be found practicable or desirable.
In lieu of a pump, a syphon or other form of extractor may be employed to
withdraw the water from the under compartment, and maintain the vacuum.