Improved Process and Apparatus for Purifying Water.
Year: 1895

page_text: Date of Application, 20th Nov., 1895
Complete Specification Left, 19th Aug., 1895-Accepted, 31st Oct., 1895
PROVISIONAL SPECIFICATION.
Improved Process and Apparatus for Purifying Water.
We, HENRY LEWIS DOULTON, Potter, and ROBERT MELDRUM, Chemist,
both of Lambeth Pottery, Lambeth, in the County of Surrey, do hereby declare
the nature of this invention to be as follows:-
This invention relates to an improved process of purifying water, an important
feature of which is that micro-organisms contained in the water are destroyed.
To the water to be purified is added a suitable quantity of some soluble substance
having the power of oxidizing organic matter, such as the various permanganates
and manganates.
We have found that impure drinking water is purified by exposing it to the
action of an excessively minute proportion of a permanganate, and then aiding and
completing such action by contact with and passage through porous earthenware
and coarsely granulated vegetable or other charcoal.
Either potassium permanganate, or sodium permanganate may be used, or these
substances may be mixed one with the other, and in order to neutralize any alkali,
which might be liberated by the action of the permanganate on certain waters, they
may be further mixed with one or more of the following salts:-Magnesium
sulphate, magnesium chloride, magnesium acetate, calcium chloride, aluminium
sulphate, ferric sulphate, ferric chloride or with any substances having the same
chemical action towards alkalies. Instead of the permanganates of sodium aud
potassium we may use permanganate of calcium, magnesium, or zinc.
The water having been treated as above described, is then passed through
filtering material such for instance as powdered or granulated charcoal, coke
or porous silica, which in addition to removing suspended matters from the
water, also have the property of abstracting the oxidizing agent which has been
added.
The process is conducted in an apparatus which supplies automatically a suitable
quantity of oxidizing material to the water to be purified. The following is a
description of a type of our improved filter constructed preferably of pottery.
a
The water to be purified when poured into the filter, is made to flow over
perforated pocket containing the reagents before referred to and the water which
is retained in the pocket forms a saturated solution of such reagents, whilst a
portion is displaced and flows into the vessel below.
Thus each time water is poured into the filter, it receives a certain quantity of
reagent.
As an alternative, the reagent may be contained in a receptacle of asbestos cloth,
porous pottery, porous stone, or other material by means of which a like result to
that just described may be obtained.
Beneath the receptacle above described is a vessel which is designed to retain
the water while the process of oxidization takes place. With this object in view
the vessel is provided with an outlet covered by some porous material, such for
instance as asbestos cloth, porous pottery, porous stone or silica.
The bacteria in the water are deposited on or near the surface of this material,
and being thereby continuously exposed to the action of the oxidizing agent, are
thus rendered inert.
Beneath the vessel just described is a chamber which contains filtering material
such as powdered or granulated charcoal, coke, porous silica or the like. This

page_text: may extend to the bottom of the filter, so that the purified water remains in
contact with it until drawn off for use by means of a tap provided for the purpose.
Or, if preferred, a chamber may be provided beneath the filtering material for the
storage of the purified water.
Dated this 19th day of November 1895.
H. L. DOULTON.
ROBERT MELDRUM.
We, HENRY LEWIS DOULTON, Potter, and ROBERT MELDRUM, Chemist,
both of Lambeth Pottery Lambeth in the County of Surrey, do hereby declare
the nature of this invention and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement :-
This invention relates to an improved process of purifying water, an important
feature of which is that micro-organisms contained in the water are destroyed.
To the water to be purified is added a suitable quantity of some soluble substance
having the power of oxidizing organic matter, such as the various permanganates
and manganates.
We have found that impure drinking water is purified by exposing it to the
action of an excessively minute proportion of a permanganate, and then aiding and
completing such action by contact with and passage through porous earthenware
and coarsely granulated vegetable or other charcoal.
Either potassium permanganate, or sodium permanganate may be used, or these
substances may be mixed one with the other, and in order to neutralize any alkali,
which might be liberated by the action of the permanganate on certain waters, they
may be further mixed with one or more of the following salts:-Magnesium
sulphate, magnesium chloride, magnesium acetate, calcium chloride, aluminium
sulphate, ferric sulphate, ferric chloride, or with any substances having the same
chemical action towards alkalies. Instead of the permanganates of sodium and
potassium we may use permanganate of calcium, magnesium, or zinc.
The water having been treated as above described, is then passed through
filtering material such for instance as powdered or granulated charcoal, coke or
porous silica, which in addition to removing suspended matters from the water also
have the property of abstracting the oxidizing agent which has been added.
The process is conducted in an apparatus which supplies automatically a suitable
quantity of oxidizing material to the water to be purified. The following is a
description of a type of our improved filter constructed preferably of pottery and
shewn in vertical section at Figure 1.
The water to be purified when poured into the upper vessel A of the filter, flows
over a pocket B perforated at C containing the reagents before referred to and the
water which is retained in the pocket forms a saturated solution of such reagents.
whilst a portion is displaced and flows with the main body of the water through
the holes D into the vessel E below.
Thus each time water is poured into the filter, it receives a certain quantity of
reagent.
As an alternative, the pocket B instead of being perforated may be made of
asbestos cloth, porous pottery, porous stone or other material by means of which a
like result to that just described may be obtained.
Beneath the receptacle above described is a vessel E which is designed to retain
the water while the process of oxidization takes place. With this object in view the
vessel is provided with an outlet F covered by some porous material G, such for
instance as asbestos cloth, porous pottery, porous stone or silica.

page_text: The bacteria in the water are deposited on or near the surface of this material
and being thereby continuously exposed to the action of the oxidizing agent, are
thus rendered inert.
Beneath the vessel just described is a chamber H, which contains filtering
material such as powdered or granulated charcoal, coke, porous silica or the like.
This may extend to the bottom of the filter so that the purified water remains in
contact with it until drawn off for use by means of a tap J provided for the purpose.
Or, if preferred, a chamber may be provided beneath the filtering material for the
storage of the purified water.
At
Preferably however we employ the apparatus forming the subject of the
Application No. 9137 of 1896 which is shown in vertical section at Figure 2.
the bottom of the upper vessel a is a porous slab b supporting a filter bed c,
preferably of iron oxide above which is a perforated slab d supporting the
chamber e containing the reagents. This chamber is perforated at f, and has an
air pipe g leading up from its top, it is surrounded by the cone h.
When water is poured into the vessel a some of it flows through the perforations f
and rises in the pipe g, in which the water level is always the same as in the vessel a.
The water thus entering the chamber e mixes with the saturated solution of the
reagent in it, and when the water level in the vessel a falls some of the solution
flows out through the perforations and mixes with the unfiltered water, the two
passing together to the filter c. This filter arrests the reagent, and the filtered
water passes through the slab and hole j, to the second filter bed k, which
is preferably of vegetable charcoal in which it remains until drawn off by the
tap 1.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The process of purifying water consisting in adding to it a soluble substance
having the power of oxidising organic matter and then filtering it substantially as
described.
2. The combination with a filter of means whereby a suitable quantity of
oxidising material is automatically added to the water substantially as described.
3. Apparatus substantially as described and shewn at Figure 1 of the
drawings.
Dated this 17th day of August 1896.
H. L. DOULTON.
ROBERT MELDRUM.