Improvements in or relating to Processes and Apparatus for the Purification of Drinking-water.
Year: 1895

page_text: Date of Application, 15th Oct., 1895
Complete Specification Left, 10th July, 1896-Accepted, 22nd Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Processes and Apparatus for the
Purification of Drinking-water.
I, HENRI JOSEPH NAPOLÉON BERGE, University Professor and Director of
the Municipal Laboratory of the City of Brussels, in the Kingdom of Belgium,
do hereby declare the nature of this invention to be as follows:-
The purifying processes for drinking waters and the apparatus for effecting the
same industrially, which are the subject of this invention constitute new elements
contributed to the well-known system, based on the liming of waters, and their
ultimate neutralisation, with a view to rendering them potable.
From the chemical point of view, the neutralisation is notably simplified by
the substitution of a soluble salt of iron in place of carbonic acid.
From the
purely mechanical point of view, the construction of the apparatus is very
materially simplified, so that the process as a whole is rendered extremely
economical.
The apparatus, as a whole, which I commend, is applicable, in its main lines
and principal features, equally well to the calcareo-carbonic system as to the new
mode of procedure above indicated. I will therefore proceed, in the first place, to
set forth the course to be followed for the sterilisation of waters by the aid of
the process of lime and carbonic acid, because in this manner it will be more easy
to comprehend the adaptation of this plant to the calcareo-ferric process.
The new mode of purification is distinguished, from the old method, in the first
place, by a new and special process of liming waters which are to be freed from
bacteria. In the old system the liming was effected by the direct introduction of
the lime into the water to be sterilised; and as the bacteria are only present in
inconsiderable quantities it frequently happens that the mixture is inefficient, and
the object, viz., sterilisation, is not attained; whereas, on the contrary, the new
process entirely obviates this defect in the sense that the mixture is effected by
the confluence of the water to be provided with a milk of lime, previously prepared
of the desired strength, in a mixing-cone, whence the mixture flows by a discharging
and decanting canal, in order to pass through a separator arranged with partitions,
and finally to reach, freed of all its solid particles, the carbonating apparatus,
which is also of special construction. The neutralised water passes thence into a
further decanting channel, whence it flows finally into a reservoir, in the condition
of a potable water.
This process, has further, the advantage of being perfectly continuous, inasmuch
as the sole operations to be attended to consist in maintaining the supply of milk
of lime, and keeping the lime-furnace producing the carbonic acid gas.
The milk of lime is prepared in a vat or reservoir, provided with a discharge-
cock above the mixing-cone or funnel in which the water arrives by the delivery-
pipe, and wherein a kind of whirlpool is created against the sloping walls of the
funnel, whereby the intimate admixture of the two liquids is effected.
The water thus sterilised falls into the decanting canal, provided with obstacles
or baffle-plates, and wherein it deposits a portion of the solid particles held in
suspension by it, of which it is completely freed in passing through separators,
from which it emerges, by another canal, to arrive at the carbonator entirely

page_text: clarified, and containing nothing more than the dissolved lime to absorb the
quantity of carbonic acid necessary to transform it into carbonate<.
The carbonic acid, generated in a lime-furnace, analogous to those employed in
sugar-factories passes through a purifier, to be absorbed by the limed water in a
"trompe or injector device. This device consists of an enlarged cylinder
surrounding the discharge-pipe of limed water which draws in an absorbs the
carbonic acid gas in its curved course, or by any other arrangement of baffle-plates.
The water and carbonates flow thence into a channel fitted with baffle-plates, where
the carbonates are precipitated, leaving the water, perfectly clear and fit for supply
for drinking purposes, to flow into the reservoir.
The plant above described is intended only to serve as an example, and it is
obvious that it may be modified in detail without thereby destroying the characteristic
of the new elements which govern and distinguish the system.
As before mentioned, the new method of purification is materially simplified
when the neutralisation by the employment of a soluble salt of iron is substituted
in place of the carbonic acid neutralisation.
In this manner, and for this purpose, the residuals of iron pyrites and of copper
pyrites may be advantageously employed, after calcination.
But these materials are disposed of in great abundance, as residuals from the
manufacture of sulphuric acid, notably by large manufacturers of cellulose, so that
this product which has only an insignificant value, is naturally most economical for
this purpose; and the more so inasmuch as the value of the pyrites is in no way
diminished by their employment in the manner proposed for this process, which in
fact only constitutes a washing whereby, on the contrary, the quantity of sulphur
contained in them is netually diminished, whereby in short their real value is
rather increased.
The operation is carried out in the following manner ;—
Exactly as in the calcareo-carbonie process, the water to be sterilised is mixed
with milk of lime in apparatus identical with those above-described, but before
falling into the decanting channel it passes through paste-separators, enclosed
preferably between two parallel metallic sheets the intervals between the sheets
being filled with a paste made of the bisulphite of cotton, or other the like filtering
material. The limed water passes from the mixing cone into a second mixing cone,
arranged at a little distance below the first cone, and into which discharges itself
the washing water of the residuals of pyrites, prepared in a second reservoir, to
mis with the aforesaid limed water; and it is this mixture which in fine is receivel
in the decanting vat and passes through the three separators, with partitions above
described.
The water of the first reservoir is limed, say, eg. in the proportion of two
hundred grammes of lime to the cubic metre of water from pyrites, and may be at
about Beaumé the cubic metre of water; but these quantities and proportions
may vary, according to the source and nature of the water used.
The limed water, issuing from the first funnel, in confluence with the pyrites-
wash water in the second tunnel, is immediately neutralised. Weakly titrated in
calcareous matter, and containing no iron, it is absolutely freed from all bacteria,
and is ready for use as a potable water, after simply passing through the decanting
vat, and the separators, whence it flows directly into the reservoir, without further
treatment of any kind : quite contrary to what is necessary for carbonic neutralisa-
tion, so that this modified form of neutralisation (or sterilisation) considerably
simplifies the process, from all possible points of view.
The simplicity of these apparatus, resulting from the arrangements above
described, permits the fitting up of plant of small dimensions for domestic purposes,
which are thoroughly effective sterilisers. This form comprises a cylinder mounted
on a reservoir. In the cylinder are suspended the two mixing cones, whereof the
former communicates with the receptacle for the milk of lime, and the other with
that for pyrites water. Below the funnel lies the inclined decanting filter, and in
the middle of the reservoir is situated a cylinder made of payer-paste. The

page_text: mixture from the water supply pipe and the two mixing cones, falls on the
separating filter, into which it penetrates, to be drawn off as potable water by a
draw-off cock.
Dated this 15th day of October 1895
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to Processes and Apparatus for the
Purification of Drinking-water.
1, HENRI JOSEPH NAPOLEON BERGE, University Professor and Director of
the Municipal Laboratory of the City of Brussels, in the Kingdom of Belgium,
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 :-
The purifying processes for drinking water and the apparatus for effecting the
same industrially, which are the subject of this invention constitute new elements
contributed to the well known system, based on the liming of water, and its
ultimate neutralization, with a view to rendering them potable.
From the chemical point of view, the neutralization is notably simplified by
the substitution of a soluble salt of iron in place of carbonic acid.
From a
purely mechanical point of view, the construction of the apparatus is very
materially simplified, so that the process as a whole is rendered extremely
economical.
The apparatus, as a whole which I recommend, is applicable, in its main lines
and principal features, equally well to the calcareo-carb mic system as to the new
mode of procedure above indicated. I will therefore proceed, in the first place,
to set forth the course to be followed for the sterilization of waters by the
aid of the lime and carbonic acid, because in this manner it will be more easy to
comprehend the adaptations of this plant to the calcareo-ferric process.
These apparatus are illustrated, more or less diagrammatically in the accom-
panying drawings, wherein:
Figures 1 & 1 are side elevations of the plant adapted for use with carbonic
neutralisation;
Figure 2 is a front elevation of the same;
Figure 3 shows the aspirating and water-blowing device for the carboni -acid, in
vertical central section;
Figure 4 is a side elevation of plant, adapted for ferric neutralization;
Figure 5 is a form of apparatus for a domestic installation on a small scale.
The new mode of purification is distinguished, from the old method, in the first
place, by a new and special process of liming waters which are to be freed from
bacteria. In the old system the liming was effected by the direct introduction of
the lime into the water to be sterilised; and as the bacteria are only present in
inconsiderable quantities, it frequently happens that the mixture is inefficient, and
the object, viz., sterilisation, is not attained; whereas, on the contrary, the new
rocess entirely obviates this defect, in the sense that the mixture is effected by
the confluence or the water to be provided with a milk of lime, previously prepared
of the desired strength, in a mixing-cone, whence the mixture flows by a discharging
and decanting canal, in order to pass through a separator arranged with partitions,
and finally to reach, freed of all its solid particles, the carbonating apparatus,
which is also of special construction. The neutralised water passes thence into
a further decanting channel, whence it flows finally into a reservoir, in the condition
of a potable water.

page_text: This process has, further, the advantage of being perfectly continuous, insinuch
ns the sole operations to be attended to consist in maintaining the supply of milk of
lime, and keeping the lime furnace producing the carbonic acid gas.
The milk of time is prepared in a vat or reservoir b, provided with a discharge-
cock above the mixing-cone or funnel c, in which the water arrives by the
delivery-pipe a, and wherein a kind of whirlpool is created against the sloping
walls of the funnel, whereby the intimate admixture of the two liquids is
effected.
The water thus sterilised falls into the decanting canal d, provided with obstacles
or baffle-plates (as shown) and wherein it deposits a portion of the solid particles
held in suspension by it, of which it is completely freed in passing through the
separators e, from which it emerges by the canal f, to arrive at the carbonator
entirely clarified, and containing nothing more than the dissolved lime to absorb the
quantity of carbonic acid necessary to transform it into carbonates.
The carbonic acid, generated in a lime furnaceg, analogous to those employed in
sugar-factories passes through a purifier h, to be absorbed by the limed water in a
trompe
or injector device, whereof the construction is shown in detail
in Figure 3. This device consists of an enlarged sleeve m surrounding the limed
water discharge-pipe which draws in and absorbs the carb mic acid gas in its curved
course, or by any other arrangement of baffle-plates. The water and carbonates
flow the nee into the channel fitted with baffle plates, where the carbonates are
precipitated, leaving the water, perfectly clear and fit for supply for drinking
purposes, to flow into the reservoir K.
The plant above described is intended only to serve as an example, and it
is obvious that it may be modified in detail without thereby destroying the
characteristics of the new elements which govern and distinguish the system.
As before mentioned, the improved method of purification is materially simplified
when the neutralisation, by the employment of a soluble salt of iron, is substitute 1
in place of the carbonic acid neutralisation.
In this manner, and for this purpose, the residues of iron pyrites and of copper
pyrites may be advantageously employed, after calcination.
These materials are disposed of in great al lance, as residuals from the
manufacture of sulphuric acid, notably by large manufacturers of cellulose, so that
this product, which has only an insignificant value, is naturally most economical
for this purpose; and the more so inasmuch as the value of the pyrites is in no way
diminished by their employment in the manner proposed for this process, which
in fact only constitutes a washing whereby, on the contrary, the quantity of
sulphur contained in them is actually diminished, whereby in short their actual
value is rather increased.
The operation is carried out in the following manner :-
Exactly as in the calcare-carbonic process, the water to be sterilised is in
confluence with mith of lime in apparatus identical with those above-described, as
shown in Fig. 4; but before falling into the decanting channel d it passes through
paste-separators ee, enclosed preferably between two parallel metallic sheets, the
intervals between the sheets being filled with a paste made of the bisulphite of
coitou, or other the like filtering material. The limed water passes from the mixing
cone e (Fig. 4) into a second mixing cone e 1, arranged at a little distance below
the first come, and into which the washing water of the residues of pyrites,
(prepared in a second reservoir 61) discharges itself, in confluence with the
aforesaid limed water; and it is this last mixture which is received in the
decanting vat dard passes through the three separators, with partitions e e, above
described.
The water of the first reservoir is limed, say, for example, in the proportion
of 200 grammes of lime to the cubic metre of the pyrite washing water, and may
be at about 20 Benumé the cubic metre of water; but these quantities and
proportions may vary, according to the source and nature of the water used.
The limed water, issuing from the funnel e, in confluence with the pyrites

page_text: washing water in the funnel e 1, is immediately neutralised. Weakly titrated with
calcareous matter, and containing no iron, it is absolutely freed from all bacteria,
and is ready for use as a potable water, after simply passing through the decanting
vat, and the separators, whence it flows directly into the reservoir K, without
further treatment of any kind quite contrary to what is necessary for carbonic
neutralisation, so that this modified form of neutralisation (or sterilisation)
considerably simplifies the process, from all possible points of view.
The simplicity of these apparatus resulting from the arrangements above
described, permits the fitting up of plant of small dimensions for domestic
purposes, which thus constitute thoroughly effective sterilisers, of which I have
here shown, by way of example, a constructive variation, in Fig. 5. This example
comprises a cylinder A mounted on a reservoir B. In the cylinder A are suspended
the two mixing cones e c1, whereof the former communicates with the receptacle ()
for the milk of lime b, and the other with that for pyrites water, b 1. Below the
funnel lies the inclined decanting filter d, and in the middle of the reservoir B is
situated a cylindrical filtere made of paper-paste; R is the draw-off cock. As is
evident, the mixture from the water supply pipe C and the two mixing cones eet,
falls on the separating filter, through which it penetrates, to be drawn off as potable
water by the cock R.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is: -
1. A process for purifying water on the basis of sterilisation by lime characterised
by liming the said water by the confluence of the water to be sterilised with a
milk of lime prepared beforehand and by the after neutralisation of the limed
water obtained by this process either before or after the clarifying of the
liquid.
2. In the process of liming described in Claim 1 the mode of construction of the
mixing devices characterised by their cone-shaped section for the purpose of
obtaining
tely perfect and intimate admixture of the fluids to ensure the
complete sterilisation of every part of the water passing through them.
3. In the purifying process set forth in Claim 1 the carbonic neutralisation
characterised by the aspiration of carbonic acid into a trompe or injector device
under the action of the water absorbed in its passage.
4. In the purifying process for water mentioned in Claim the neutralisation by
means of wash-water from roasted pyrites and for that purpose the combination of
a second cone for the mixing of the said pyrites wash-water with the limed and
sterilised water to the desired degree.
5. For the carrying out of the process of purification of water characterised by
an apparatus specially distinguished by its constructive form and comprising an
upper cylinder provided with mixing apparatus and with recipients for the
ingredients all mounted on the top of a reservoir provided with a central filter
from which the former is separated by an inclined decanting filter, for the purpose
of constituting a completely sterilising domestic filtering apparatus with a free
discharge of potable water.
Dated this 10th day of July 1896
BOULT & WADE,
Agents for the Applicant.