A New or Improved Method of and Apparatus for Filtering and Purifying Liquids.
Year: 1896

page_text: Date of Application, 7th Feb., 1896
Complete Specification Left, 7th Dec., 1896-Accepted, 9th Jan., 1897
PROVISIONAL SPECIFICATION.
A New or Improved Method of and Apparatus for Filtering and
Purifying Liquids.
1, JAMES GRIEVE LORRAIN, of Norfolk House, Norfolk Street, Strand,
London, W.C. in the County of Middlesex, Consulting Engineer, do hereby declare
the nature of this invention to be as follows:-
My invention consists not only of filtering and purifying apparatus but also of a
method of filtering and purifying impure liquids.
My invention, in so far as it relates to the method, consists in purifying the
liquid by filtering it through a suitable purifying material hereinafter to be
described so arranged or disposed in a compartment so constructed that the said
liquid shall be free to pass through said material and out of the said compartment
more quickly than it can enter the same, and at the same time in supplying air to
the said material.
My invention, in so far as the apparatus is concerned, consists mainly of what I
shall term a differential-flow compartment with purifying material of the said kind
arranged therein and offering less resistance to the flow of the liquid through it
than the medium through which the liquid enters said compartment and means for
supplying air or oxygen to said material. To these essential features of my
invention I may add any of the other well known devices employed with filters, such
for example as a compartment for the impure liquid, one for the reception of the
purified liquid, a cap or cover for excluding dust, inlet or outlet taps, et cetera.
Having thus described my invention in general terms so as to define its scope,
I shall now, in order that it may be more readily understood, proceed to describe it
more in detail; and for that purpose I shall refer by way of types or examples to
two modifications of one contemplated form of my invention.
The first of the said modifications consists of a filter designed for water which is
already free from solid mechanically suspended matter or which has already been
filtered by an ordinary filter but which may still contain deleterious oxidisablé
matter in solution such as sewer gas, for example. It consists of a cylindrical case
of earthenware or other suitable material, having a chamber for containing the
impure water to be filtered and a chamber for the reception of the purified water.
Between the two chambers, and resting upon an annular ledge is the compartiment
for containing the purifying material which consists preferably of platinized carbon
or other porous material, coated and or impregnated with a catalytic metal. In
order that such material may exert a purifying catalytic action it is necessary that
oxygen be freely supplied to the said material. For this purpose I employ a tube
which extends from the purifying compartment upwards to the air space under the
cap or cover of the filter. But the mere provision of such an air tube would not in
itself be sufficient in all cases; for it is obvious that if the compartment containing
the purifying material were constructed and the material arranged therein as in
ordinary filters the water would flow into it as quickly or nearly as quickly as it
would flow out of it; so that the material would be wholly immersed in water and
there would be little or no oxygen drawn into the compartment to combine with
the sewer gas or other impurity in the water so as to purify the latter under the
influence of the catalytic material. It is, therefore, necessary to provide that 'the

page_text: water shall be free to flow through the purifying material and out of the purifying
chamber faster than it can come into the said chamber so that the material shall not
be wholly submerged so to speak in the water and so that air shall be sucked down
the tube. I may effect this object by disposing the purifying material between two
perforated plates, of which the upper shall have a smaller number of orifices, or
orifices of smaller gauge, than the lower so that the water may pass more rapidly
out of the purifying chamber into the receptacle for the purified water than it can
pass from the chamber containing the impure water to be filtered into the purifying
chamber, and further by having the granules or pieces of the purifying material of
such size that their interstitial spaces shall be greater than the orifice spaces of the
upper plate or in other words so that the purifying material shall offer less resist-
ance to the passage of the water than does the said upper plate and at the same
time offer more resistance than the lower plate. By this means the pieces or
particles of purifying material instead of becoming submerged in water, are only
covered by a film of water passing rapidly over or through or between them and
are therefore in the most favourable condition for absorbing oxygen from the air
sucked in through the pipe. What I term a "differential-flow" contrivance is
thus obtained.
To use this filter, water is poured into the space above the upper plate (but not
into the tube) whence it flows through the upper plate, then through the purifying
material, and finally through the lower plate into the receptacle for the purified
water. At the same time air is sucked down the tube, by means of the differential-
flow action in the purifying chamber, from the air space above the level of the
impure water, which air space may be replenished from the external atmosphere in
the usual manner through orifices or corrugations between the filtering vessel and
its cover. When in the purifying chamber the oxygen of the air sucked down the
tube, and the oxidisable impurities in the water, come together and combine under
the catalytic influence of the purifying material.
As I have said, the modification just described is not specially adapted for
removing solid matter from the liquid to be filtered.
When I desire to remove such
solid matter I may add a straining device of any convenient known kind to the
apparatus mentioned and this I preferably place above the purifying material so
that the solid matter may be strained from the liquid before the latter reaches the
purifying material. This straining device may consist of any material which will
act as a sieve, so to speak, or in other words allow water to pass but retain solid
particles, such for example, as a plate of porous ware, a sheet of asbestos fabric, or
the like. The upper plate hereinbefore mentioned would act as a straining device if
the orifices were small enough. However, the straining device which I contemplate
using in the second modification hereinbefore referred to consists of a layer of sand
placed above the upper perforated plate and prevented from passing through the
perforations of the latter by an interposed sheet of asbestos fabric. To prevent the
layer of sand being disturbed by the water poured into the vessel, I may place upon
the said sand a layer of asbestos fabric, and upon this latter I sometimes place
another perforated plate. It will be seen that the water is strained from solid
matter before it reaches the purifying material by which it is purified by the
oxidation of the liquid or gaseous oxidisable matter present.
I desire it to be understood that I do not limit myself to the details of construction
bereinbefore mentioned; and I further desire it. to be understood that by the term
"differential-flow compartment" I mean a compartment out of which a liquid will
flow more quickly than it can enter and by the term "differential-flow con-
trivance" mean the combination of a differential-flow compartment with a
purifying material of such character and arranged therein in such manner that the
said material will offer less resistance to the flow of liquid through it than will the
medium through which the liquid enters the said compartment, and more resistance
than the medium through which the liquid leaves the said compartment. By this
means no water can collect on the bottom of the said compartment so as to submerge
any of the purifying material.

page_text: A purifying material which I contemplate employing is charcoal coaton
impregnated with platinum black. I may su coat and impregnate the charcoal by
treating with platinous chloride and then heating in a closed vessel or in a current
of suitable gas or the like. Or instead of employing charcoal as a base for the
catalytic metal I may employ porous earthenware, dried clay, unglazed porcelain,
steatite, meerschaum or other porous mineral.
1896
ADDIN
D
A New or Improved Method of and Apparatus for Filtering and
Purifying Liquids.
I, JAMES GRIEVE LORRAIN, of Norfolk House, Norfolk Street, Strand,
London, W.C. in the County of Middlesex, Consulting Engineer, do hereby
eclare 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
tatement:-
My invention consists not only of filtering and purifying apparatus but also of a
method of filtering and purifying impure liquids.
My invention, in so far as it relates to the method, consists in purifying the
liquid by filtering it through a suitable purifying material hereafter to be described
so arranged or disposed in a compartment so constructed that the said liquid
shall be free to pass through said material and out of the said compartment more
quickly than it can enter the same, and at the same in supplying air to the said
inaterial.
My invention, in so far as the apparatus is concerned, consists mainly of what
I term a differential-flow compartment with purifying material of the said kind
arranged therein and offering less resistance to the flow of the liquid through it
than does the medium through which the liquid enters said compartment and more
resistance than the medium through which the liquid leaves the said compartment,
and means for supplying air or oxygen to the said material. To these essential
features of my apparatus I may add any of the other well known devices employed
with filters, such for example as a compartment for the impure liquid, one for the
reception of the purified liquid, a cap or cover for excluding dust, inlet or outlet
taps, and the like.
Having thus described my invention in general terms so as to define its scope,
1 shall now, in order that it may be more readily understood, proceed to describe
it more in detail; and for that purpose I shall refer by way of types cr examples
to the annexed sheets of drawings which represent two modificatious of one form of
my invention.
Fig. 1, is a vertical section of a form of my filter designed for water which is
already free from solid mechanically suspended matter or water which has already
been filtered by an ordinary filter but which may still contain deleterious oxidisable
matter in solution such as sewer gas, for example. It consists of a cylindrical case
of earthenware or other suitable material. A is the chamber for containing the
5 impure water and B is a chamber for the reception of the purified water. Between
the two chambers, A and B, and resting upon the annular ledges (shown in the
figure) is the compartment for containing the purifying material G, which consists
preferably of platinized carbon or other porous material coated and or impregnated
with a catalytic metal. In order that such material may exert a purifying catalytic
50. action it is necessary that oxygen be freely supplied to the said material.
For this

page_text: purpose employ the tube H, which extends from the purifying compartment
upwards to the air space under the cap or cover of the filter. But the mere
-provision of the air-tube H, would not in itself be sufficient in all cases; for if the
compartment containing the purifying material were constructed and the material
arranged therein as in ordinary filters the water would flow into it from A, as
quickly as or more quickly than it would flow out of it into B; so that the material G,
would be wholly immersed in water and there would be little or no oxygen drawn
into the compartment to combine with the sewer gas or other impurity in the water
so as to purify the latter under the influence of the purifying material. I, therefore,
so provide that the water shall be free to flow through the purifying material and
out of the purifying chamber faster than it can come into the said chamber so that
the material shall not be submerged in the water and so that air shall be sucked
down the tube H. I may effect this object by disposing the purifying material
between the two perforated plates E and F, of which the upper shall have a smaller
number of orifices, or orifices of smaller gauge, than the lower so that the water
may pass more rapidly through F into B, than it can pass from A through E and
further by having the granules or pieces of the purifying material G, of such size
that their interstitial spaces (for convenience I show the said pieces by means of
circles), shall be greater than the orifice spaces of the upper plate or in other words
.so that the material G shall offer less resistance to the passage of the water than
. does the plate E and at the same time offer more resistance than the pinte F. By
this means the pieces of partying material instead of becoming wholly immersed
in water, are only covered by a film of water passing rapidly over or through or
between them and are therefore in the most favourable condition for absorbing
oxygen from the air sucked in through the pipe H. What I term a "differential-
flow contrivance is thus obtained.
To use the filter, water is poured into the space A (but not into the tube H)
whence it flows through the perforated earthenware plate E, then through the
material G, and finally through the perforated plate F, into the chamber B. At
the same time air is sucked down the tube H, by means of the differential-flow
action in the purifying chamber from the air space above the level of the water
in A, which air space is replenished from the atmosphere in the usual manner
through orifices or corrugations between the filtering vessel and its cover as shown
by the arrowe. When in the purifying chamber the oxygen of the air sucked
down the tube H, and the oxidisable impurities in the water come together and
combine under the catalytic influence of the purifying material.
As I have said the apparatus shown in Fig. 1 is not adapted for removing solid
matter from the liquid to be purified. When I desire to remove such solid matter
I may add a straining device of any convenient kind to the apparatus shown in
Fig. 1, and this I preferably place above the material G, so that the solid matter
may be strained from the liquid before the latter reaches the catalytic purifying
inaterial G. This straining device may consist of any material which will act as
a sieve, so to speak, or in other words allow water to pass but retain solid particles,
such, for example, as a plate of porous ware, a sheet of asbestos fabric, or the like.
The plate E would act as a straining device if the orifices were small enough.
However, the straining device which I have found most satisfactory hitherto is
shown in Fig. 2. It consists of a layer of sand D, placed above the perforated
plate E, and prevented from passing through the perforations of the latter by the
interposed sheet of asbestos fabric D'. To prevent the layer of sand D, being
disturbed by the water poured into A, I may place upon it the layer of asbestos
fabric D, and upon this latter I sometimes place the perforated plate C. It will
be seen that the water is strained from solid matter before it reaches the purifying
material G, by which it is purified by the oxidation of the liquid or gaseous
oxidisable matter present.
The layer of asbestos fabric D alone makes a very good sieve for separating
the solid matter but I prefer the arrangement herein before mentioned. I desire it
to be understood that by the term "differential-flow compartment" I mean a

page_text: ompartiment out of which a liquid will flow more quickly than it can enter and
y term "differential-flow contrivance" I mean the combination of differential-.
ow compartment with a purifying material of such character and arranged therein
such manner that the said material will offer less resistance to the flow of the
quid through it than will the medium through which the liquid enters the said
ompartiment but more resistance than the medium through which it passes out of
be said compartment.
I desire to draw particular attention to the effect of submitting the liquid to the
ction of the catalytic material in the form of a mere film. In this form the
oxidation of the impurities appears to be much more energetic than would be
anticipated. From my experiments it would appear as if the thin film of water
had a special property of abstracting oxygen from the air and rapidly drawing it
through from its surface which is in contact with the air to its surface which is in
contact with the catalytic material and so increasing the rate of oxidation. I am
not sure that the film does exert this selective effect and I mention it as a
hypothesis merely. For the purpose of this specification I shall term such effect.
the "film effect."
In practice I prefer to make the body of the filter, the plates G, E, F, and the
tube H, of strong glazed earthenware. The size of the pieces of catalytic material
does not appear to be important provided that the differential flow and the film.
effect is obtained. Other things being equal I prefer to have the film as thin as-
possible.
Having now particularly described and ascertained the nature of my said!
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. The method of obtaining what I have termed the film effect substantially as-
set forth.
2. The method of purifying a liquid which consists in subjecting it in the form
of a film to the action of a catalytic metal or porous body coated and or
impregnated by a catalytic metal arranged in a differential flow compartment to
which air is supplied.
3. The herein described method of purifying liquids which consists in passing
the liquid first through a medium offering considerable resistance to its flow, then
through purifying material of the nature specified and so arranged so as to offer
less resistance to its flow than the first medium, and finally through a medium
offering less resistance to the flow of the liquid than the said purifying material,
and at the same time supplying air to the said purifying material in order that the
oxygen of the said air may be caused to combine with the oxidisable matter
present in the said liquid under the influence of the said material.
4. In apparatus for purifying liquids the combination of a differential flow
compartment, purifying material of the nature specified arranged within said.
differential flow compartment and offering less resistance to the flow of the liquid
than the medium by which the liquid enters the said compartment and more-
resistance than the medium through which the liquid leaves the compartment,.
5 and means for supplying air to the said purifying material in order that the
oxygen of the said air may be caused to combine with the oxidisable matter
present in the said liquid under the influence of the said material.
5. lu apparatus for purifying liquids the combination of a differential flow
compartment, porous material coated with a catalytic metal arranged within said
0 differential flow compartment and offering less resistance to the flow of the liquid
than the medium by which the liquid enters the said compartment and more
resistance than the medium through which the liquid leaves the compartment, and
means for supplying air to the said porous material coated with a catalytic metal
in order that the oxygen of the said air may be caused to combine with the
5 oxidisable matter present in the said liquid under the influence of the said porous
material coated with a catalytic metal.

page_text: 6. In apparatus for purifying liquids the combination of a differential flow
compartment, catalytic purifying material arranged within the said differential
flow compartment and offering less resistance to the flow of the liquid than the
medium by which the liquid enters the said compartment and more resistance than
the medium through which the liquid leaves the compartment, and an air tube or
its equivalent for supplying air to the said catalytic purifying material in order
that the oxygen of the said air may be caused to combine with the oxidisable
matter present in the said liquid under the influence of the said catalytic
material.