Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to cenkrifugal
separators for liquids and~is particularly intended for use
in~the milk industry but may àlso be~used for mineral oils,
vegetable oils or other liquid mixtures in which, due to the
centrifugal force; the liquids are separated in their
different components which have different density.
~ A~centrifugal separator of this type is desaribed in
; Canadian Patent No. 1,218,817 assigned to the same assignee
and issued on April 19, l990.
10The earlier invention provides that the li~uids
having different density are separated under the action of
the centrifugal force of the apparatus by being caused to
ascond within annular concentric conduits formed in the
rotating part of the apparatus and then~ being distributed
through conduits formed in~the fixed head of tho apparatus~
or the various destinations.
The hermetlc seals between the rotating part of the
apparatus and the fixed head are ensured in the earlier
invention by means of moveable rings which rota;te together
~0 with the rotating part of!the`apparatus, tho rings coming in
aontact with other~rings flxod resiliently to the fixed upper
part of the~ appa~ratus, ~a fact which eliminates any
posslbillty of contact of the various liquid phases with the
atmosphere. Suitable conduits
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are provided for letting cooling water under pressure flow
through for the purpose of cooling both the fixed rings as -~
well as the rotating rings which guarantee the seal. -
The seal between the movable rings and the fixed
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rings is ensured in the apparatus according to the earlier
invention by suitable springs which act on rings which do not
rotate because they are disposed on the fixed part of the
apparatus but are subjected to the action of the compression
springs which push the rings downwardly. Therefore, the
rings which do not rotate~are compelled to remain in contact
with the movable rings located in the rotating part of the
apparatus, thus avoiding that the liquids separated due to
the centrifugal force mix again among themselves.
The solution gives rise, howeverj to some drawbacks
due mainly to the complexity of the hydraulic circuits
involved in the separation of the liquids as well as the
presence of the compression springs which involve very
vulnerable structures, which require continuous control and
require frequent replacement as the result also of the
properties of the liquids being used.
An object of the present invention is to improve
the centrifugal separator of the earlier invention and to
eliminate the drawbacks mentioned hereinabove.
In the present invention the fixed head of the
apparatus is substantially simplified and the seals between
the several axial conduits are ensured by shaped rings which
are movable with respect to the fixed parts of the apparatus.
.
These movable rings come in contact with rings which are ~ ;
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fixed with respect to the rotating parts of the apparatus
because of the pressur~ of the liquids which acts on the
movable rings, thus obtaining substantial simplification of
the hydraulic circuits o~ the apparatus and permitting above
all to eliminate every type of elastic spring, thus
simplifying the operation and the maintenance of the
apparatus.
In particular the displacement of the rings
involved in the seal causes that they are lapped directly by
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lo the components of the liquids in the apparatus, a fact which
causes absorption of the heat produced in the motion of the
rings, thus eliminating the necessity of providing cooling
of the liquids by means of water circulation as provided in
the earlier application.
The invention will be explained in more detail
hereinbelow by reference to the drawing in which:
Fig. 1 is a view of the upper part of the
centrifugal separator partially axially in cross-section with
the rotating seals according to the present invention.
As shown in Fig. 1, the liquid being handied is
introduced into the centrifugal separator through the central
conduit 1 and exits a~ter having been separated in the two
phases of different specific weight through the coaxial
conduits 2 and 3. In particular the phase of lower specific
weight which ascends through the coaxial more internal
conduit 2 is brought to the coaxial conduit 4 which is
disposed in the fixed head of the apparatus at the outlets
whi}e the phase with greater specific weight which ascends
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from the external coaxial conduit 3 exits through the exit
outlet 5 which is disposed in the fixed part of the
apparatus. The arrows shown in the figure designate the
course performed by the different liquid phases.
The seal between the central inlet conduit 1 and
the first coaxial exit conduit 2 is ensured by the ring 6
which is fixed to the central part 7 of the rotor. The
movable ring 8 comes in contact with central part 7 of the
rotor. The movable ring 8 is located coaxially with respect
to the central tube 1 and comes in contact with its upper lip
8' with the fixed ring 6, under the thrust action of the
pressure of the liquid present in conduit 1, which pressure
is exerted along the direction of the arrows 9.
The stop element 10 is fixed to the central conduit
1 but limits the opening motion of the movable ring 8.
Analogously, the seal between the liquids of the
coaxial conduits 2 and 3 is ensured by the fixed ring 11
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which is EixQd to the disk 12, the latter closing in the
upper part the conduit 2 and the two rings 13 and 14. The ;
motion of the rings 13 and 14 is limited by the stop elements ~;
15 and 16 which are Eixed to conduit 4. The two rings, 13
and 14, subjected respectively to the pressure of the liquid
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of the light phase which comes from conduit 2 and to the
pressure of the liquid of the heavy phase which comes from
conduit 3.
Analogously, the external seal is ensured by the
movable ring 17 which is coaxial with the external conduit
5 and -~
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which is limited in its motion by the stop element 18, the
latter being fixed to the external wall of conduit 5. The
external seal is also ensured by the fixed ring 19 which is
fixed to the head 20 of the apparatus.
The advantages resulting from the present invention
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and specifically the head of the centrifugal separator for
the li~uids with rotating seals with respect to the head of
the earlier centrifugal separator described in the Canadian
Patent No. 1,218,817 are clear~not only with respect to the
substantial simplification in the construction of the
apparatus but also~above all because of the elimination of~
elastic elements and speclfically springs because the seal
between the moveable rings and the fixed~rings is ensured by
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the same pressure exerted by the li~uid on the same moveable
rings.
It should also be stressed that there is a
substantial advantage resulting by the cooling performed by
the same liquids on the rings, without the necessity of
providing for the cooling by means of circulation of cold
water under pressure.
Obviously, the apparatus has been described and
illustrated in the drawing attached hereto according to one
specifia embodiment which, however, has been described only
' ~ by way of a non-limiting example because the particular
constructional~details~may be~varied~in form and different
aspects, while the essential characteristics of the invention
;~ remain unchanged.
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