Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The pre~ent invention ha~ for it~ object ~o provide
a method and device for br~aking ~tabilized emulsion~.
It i~ known that certain metal salt~J when in ~olu- ~ .
tion, lower, in ~ome cases until cancelli~g it, the 'tzed"
potential on which the chemioal s~ability of a colloidal emul-
~ion depend~.
~ ffort~ have been ~ade tQ take advantage of such a
propert~ for depurating the di~charge waters o~ the cleaning
plants~ wherein ~ur~ace-active~ hydrocarbons, mud~ in the
colloidal phase and oth~r like colloidal ~ubstance~ are preBent
in widel~ var~ing percent~.
Howe~er, the use ~f said metal salt~ i~ oonditioned
by an exact value o~ the pH of the ~olution to be depurated by ;
~locculation.
Con~equently, their use is restricted by the need of
modifying~ up~tre~m and downætream the floc¢ulation proce~, the
pH o~ the colloidal solutio~, which re~uires on one hand conti- ;
nuou~ and local test~ a~d on the other hand the addition of
sub~tances correct m g said pH value, ~aid oorrecting ~ub~tances
being generall~ highly polluting sub~tance~.
~he present i~vention ha~ ~or it~ object to remove
~aid inconveniences~
~he process for breaking ~ta~ilized emulsion~ according
to the pre~ent invention compri~es:
a) a fir~t step o~ breaking of ~aid emul~ionq, during ~.
which the emulsiDn concerned i9 pa~sed through by electric ~:
currents generated by two series of pre~erably metal electrode~
immer~ed into ~aid solution a~d co~nected to the positive pole
and the ~egative on~ re~pectively of a direc~ current generator;
b) a ~eoond step of agglomeration of the ~locculat~d
particle~; -
c) a thlrd step o~ separation of the agglomerated
: , . - , - - . : . . ; , ., . , .. . ", . ~.. ... ...
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partlcle~ from the depurated water.
~ he device ~uitable to embody the invention according
to claim 1 comprises:
a) an emul~ion breaking chamber including two ~eries o~
electrode3 connected to the positive pole and the negative one
re~pectively of a direct current generator;
b) an agglomeration hopper within which the ~looculated
~aterial agglomerates;
c) a ¢hamber for 3eparating the flocculated material
~O ~rom the depurated water by di~erenca of den~ity, said
separation chamber being ~ide by ide with ~aid agglomeration ~-~
chamber and being provided o~ its bottom with means for ;~
colleoting the deposited material, and on its top with means
for removing the depurated water.
~urther, in said devioe, said first chamber i~ provided
with emulsion ~eeding mea~s arranged on the bottom of ~aid
chamher, while the means for collecting the emul~ion which
underwent said breaking proce~s are arranged in th~ upper part
of ~aid chamber, 30 that the emul~ion to be treated pa~ses
through ~aid fir3t chamber from the bottom upwards.
In said device a suitable conduit conneot~ the upper
end of ~aid fir~t chamber to the bottom of the second chamber
with a substantially hoppex-lika ~hape,
In said device the bottom o~ ~aid third chamber i9
inclined ~o a~ to convey by gravity the depo3iting material
corre~pondingly to said means for removing the deposited material.
In said devlce, said third chamber has its upper
edge arranged at a higher level than the upper edge of said
second chamber.
~inally, in ~aid de~ice, said third ohamber i~ proYidcd
on top with two spillways ~or dischargi~g the depurated liquid ~-
through o~erflow.
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The object~, ~d~anta~e~ ~nd ~eature~ of th~ invention
will urther appear in the following de~cription referring to
embodiments selected by way of example only with particular
referenoe to the accampanying drawings wherein the figure ~how
diagrammatically a cros~ ~ec~ion of a particular embodi~nt of
the invention.
~ h~ device shown in the drawing comprises a ~irst
chamber 1, called heretofore the ~tabilized emul~ion breaking
chamber9 proYid~d with a lower feeding pipe 2 for the water~ :
to be depuratad. On its top said chamber 1 i~ connected to a
downward pipe ~ feeding the water~, which have already pas~ed
through ~aid chamber 1 from the bottom upwards9 toward~ the
bottom of an open-top hopper 49 oalled heretofore the
flocculated sub~tances aggregating chamber, through a substan-
tiall~ ~ub-horizontal feeding pipe 5 whioh ln the case ooncerned
surrounds the Iower mouth of said hopper 4.
Said hopper 4 enters a third chamber 6, called hereto-
fore the ch~mber ~or separating the ~locculated sub3tance~ from
the now clean water~
S~id chamber 6 i~ open on top and comprises on two
~ide~ of its perimeter an overflowing edge 7 for the depurated
water. Ou-tside of said overflows 7 i9 provided a pipe 8 for
oonveying the now clean water whi¢h i~ then discharged through
a di~charge pi~ 9.
~he ~pper edge 10 of said hopper ~ is located quite
below said overflowing edge 7 for th0 rea~on~ explained here-
below.
Said chamber 1 comprise~, preferabl~ in ~ertical po~i-
tio~, aluminium plates 11 oonnected alternatively to the positive
pole and the negative one respestively of a direct current
generator. ~hough aluminium i~ pre~erabl~, al~o a di~ereIlt
material could be u~ed.
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Thanks to the pre~ence of -the anode~ and cathude~ in
aluminium, fed in known m~nner by a suitable current, the
breaking of the colloidal emulsion occurs in ~aid chamber 1.
In such conditions, the ~mul~ion conveyed into ~aid
hopper 4, through ~aid pipe 59 ~tartB a pro¢e~3 of agglomera-
tion of the colloidal ~ubstance~ which fall on the bottom of
~aid hopper in ~orm of flocks.
When the plant ~tarts, said flocks b~gin depo~iting
on the bottom of ~aid hopper 4 where a net 12 may be ~uitably
arranged.
When the layer of floculated material deposited on
~aid net 12 reache~ a given thickne~a, the liquid flow flowing
through the devioe according to the already ~how~ path from
said ~eeding pipe 2 to ~aid discharge pipe 9, cause~ the
~loculated material layer to gradually rise, a~ shown by po~i-
tion 13 ~ the drawin~.
When ~aid layer 13 of floculated material reache~ the
upper edge of said hopper 4, the flocks of ~aid material, owing
to their heavier gravity, fall onto the bottom o~ the chamber
6 which, as alread~ said, includes said h~pper 40
~ he bottom of ~aid chamber 6 may be provided ~uitabl~, `
in the zone ~urrounding said hopper 4, with inclined sur~ace~
14 80 as to collect in an easier way the flocks depo~ited.
The water now free o~ the polluting materiail which
separated therefrom ln form of flock~, leave~ chamber 6 through
sald overflow~ 7, pipe 8 and pipe 9.
In th~ lowest zones of the bottom of chamber 6
surrou~ding said hopper 4, are provided discharge pipes 15
for di~charging material depo~ited with a certain amount of ;-~
30 water acting a~ liquid carrying mean~.
Said di~charge pipes 15 m~r, ~n known manner~ co~ey
the material collected onto a ~iltering bed, e.g. a sand or
, , :
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ballasting bed, a porou~ material carpet, a net or t~e like5 ~!
from where the floculated material may be ea~ily collec~ed,
after drying, in the d~y pha~e.
It i~ to be ~oted that th~ eleetrode~ 11 ara subject
when acting as anode~ to wear9 and when acting a~ cathodes to be
coated by oxide~ which reduces their conducti~ity with a general
lowering in the efficiency of the whole plant. ~o thi~ end,
according to the invention, a suitably pro~lded switch rever~e~
the fu~otion OI anode and cathode OI ~aid plate~ o a~ to
reduce on one ~ide ~aid wear and to remove on the other ~ide
any po~sibility of unde~irable oxidation of the surface o~
said pla~e~ 11.
Although for desoribing reaso~s ~he in~ention ha~
been de~cribed on what above ~aid a~d ~hown by way of example
in the accompa~ying drawing, ma~y modifications and change~
may be made in embodying the invention, all of them however
having to be considered as ba~ed o~ the following claim~.
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