Note: Descriptions are shown in the official language in which they were submitted.
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'I'he present invention relates to an apparatus for
the removal of gaseous components and/or solid impurities
present in a gaseous fluid flow, said means comprising a
frame structure, an inle-t connector for the fluid flow,
accommodated wi-thin the frame structure a scrubber means, an
exit connector for carrying off the purified fluid flow, and
a connector for conductlng a scrubbing liquid into the means
and for contacting this liquid with the fluid flow, and in
said means the exit flow of the scrubbing liquid having been
disposed to pass through the fluid flow inlet connector in a
direction opposi-te to -the fluid flow.
Gaseous fluid flows frequently con-tain impurities
both in -the form of gaseous components and of solid par-
ticles, which have to be removed prior to blowing out or re-
using the fluid flow. In practice that situation is also
frequently encountered in which -the gas flow contains solid
components in such abundance that their separation is
indicated before the flow en-ters -the scrubber. It is common
in usual circums-tances to use -towards purification of the
gaseous fluid flow a wet scrubber, in which the gaseous
fluid flow is conducted into the frame portion of a separa-
tor, in other words, into a fluid tank or reaction portion,
where it is tried to bring the scrubbing liquid and the
gaseous fluid flow into -the most complete contact possible
with each other. At this scrubbing phase a-t leas-t part of
-the coarser fraction of the solid ma-tter separates and
remains in the separating tank. However, endeavours are
mostly to achieve that -the greater par-t of the solid matter
is separated in dry state already, before the scrubber,
either in a settling chamber or in a cyclone separator. By
this design the advantage is gained that the quantity of
impurities carried into the scrubbing liquid is minimized,
whence the amount of sludge that has to be carried off will
also remain minimal. After the scrubber part usually a
blower is provided because then the wear suffered by the
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hlower will be less. After the blower follows furthermore a
droplet separator; depending on the application thi.s may
consist of a
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grille, a set of gratings, droplet separators resembling a
cyclone separator, various rotating and round towers, etc.
In scrubber designs oE prior art, the blower is
usually similar to a conventional centrifugal blower. A blower
design of the so-called disintegrator -type is also known in
the art, in which -the fluid flow is directed with its impuri-
ties, as is also the scrubbing liquid. A design of this kind
requires high power inpu-t from the drive, and -the wear of the
blower is also high.
In scrubbers of -the ven-turi type, the gaseous fluid
flow is accelerated with its impurities in the venturi sec-
tion -to gain a high velocity, and a-t the same -time -the scrubb-
ing liquid is inducted into -the accelerated Eluid flow. Af-ter
the venturi section, whereat -the ve:Locity of -the gaseous Eluid
Elow is reduced, there is a droplet separa-tor, where, in the
Eirst place, the impurities serve as crys-tallisation nuclei
for the drops.
One has also towards purifica-tion of a gaseous fluid
flow employed the so-called S-wave scrubber, where the gaseous
fluidflow, after flowing together wi-th the scrubbing liquid
through an S-wave shaped slit ends up in free space and thence
further in a blower. where is no actual separate drople-t
separator: separation of droplets takes place in the free
space after the S-wave before the blower. In this design, too,
the risk is present -that supercondensing moisture may be en-
trained with -the gaseous fluid flow and therefore droplets are
flung out and into the surroundings.
The present invention provides an improvement of
scrubber designs known in the art, in particular a scrubber
design by which a high scrubbing efficiency is attained without
scrubbers requiring a high energy input. The other objec-ts of
the invention, and the advantages gainable with its aid, will
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become apparent Erom the disclosure of the inven-tion.
According to -the present invention the end region
adjacent to the scrubber means of the fluid flow inlet connec-
tor has a diminishing cross sectional diameter for the purposeof accelerating the fluid flow passing through said inlet
connector before i-t enters said scrubber means, and said
inle-t connector has been provided with holes adapted to receive the
return flow of thescrubbing liquid into said inlet connector,
said holes having been disposed in tha-t region of said inlet
connector where the fluid flow is not being accelerated,
whereby the return flow of the scrubbing liquid within the in-
let connector is prevented from being entrained with -the fluid
Elow and ef:Eects pre-purification of -the fluid flow.
According to the present invention -therefore there
i.s provldedanrapparatus for removlng gaseous components and/or
solid impurities from a gaseous fluid flow, comprising: a frame
struc-ture; scrubber means disposed within said frame structure;
discharge means -through which the purified gaseous fluid flow
is discharged from said frame structure; means for introducing
scrubbing liquid into said appara-tus and directing -the scrubb-
ing liquid into contact with said gaseous fluid flow; fluid
flow inle-t means communicating wi-th said frame structure
through which said gaseous fluid flow is in-troduced in-to said
frame struc-ture towards said scrubber means, said fluid flow
inlet means having a region through which the gaseous fluid
flow rate is not accelerated and another region through which
-the flow rate is not accelerated and another region -through
which the flow rate of -the gaseous fluid flow passing through
said inletmeans is increased prior to said scrubber means;
opening means situtated in said inlet means through which a
return flow of the scrubbing liquid passes -to enter into said
inlet means and pass there-through in opposition to the direc-
tion of the gaseous fluid flow, said opening means disposedin said region of said inlet means where the flow rate of the
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gaseous fluid flow is not accelerated and shaped and disposed
-to direct the scrubbing liquid return flow in said inlet means
in a direction opposite to the direction of gaseous fluid flow
and so that the scrubbing liquid return flow is not entrained
in -the gaseous fluid flow.
In one embodimen-t of the present invention the fluid
flow inlet means has a flow discharge orifice direc-ted -towards
said scrubber means and wherein a discharge end por-tion of
said scrubbing liquid inle-t means is disposed within said fluid
flow inlet means in -the direction of said scrubbing means to
direct the scrubbing liquid towards said discharge oriEice of
said fluid flow inlet means.
Suitably said scrubbing means comprises blower means
for further accelerating the already accelerated fluid flow
discharge from said fluid flow inlet means and for directing
a part of the purified fluid flow in the form of a recircula-
ting flow -through said opening means provided in said fluid
2U flow inlet means and into -the lat-tex, said blower means being
positioned and arranged so as -to separate drople-ts ou-t of said
fluid flow. Preferably said blower means comprises means for
flinging droplets towards said opening means in a manner so
that the scrubbing liquid passing through said opening means
into said fluid flow inlet means is set into rotary motion
within said fluid flow inlet means, whereby an efficient pre-
purifying of the fluid flow is obtained in said fluid flow
inlet means progressing in the direction opposite -to -the direc-
tion of the flow of the gaseous fluid flow -therein.
Desirably said end region of said fluid flow inlet
means has a substantially frusto-conical configura-tion taper-
ing in the direction towards said scrubber means. More pre-
ferably the apparatus comprises means for directing the gaseous
fluid flow through said inlet means in a substantially rota-
tional rnanner about a vertical axis of said inlet means, and
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in which said opening means directs said return flow of the
scrubbing liquid in-to said inlet means in a rotational direc-
tion substantially the same as -the rotational direction of
said gaseous fluid flow.
sy means of -the invention numerous significan-t ad-
vantages are gained. By the means of the inven-tion a
solution is achieved wherein only the gas which has already
been nearly purified is carried to -the final scrubbing together
with a minimal scrubbing liquid quantity, with the consequence
that the solid matter loading of -the gas is minimal. It is
-then possible to manage in the driving of the blower means
employed as scrubber means with low mo-tor outputs, without
any major amounts of energy, and at -the same -time the mos-t
efficient venturi action possible is still attained; in other
words, one achieves high scrubbing efficiency and high veloci-
-ties oE the gaseous fluid Elow, up to 60-100 m/s for ins-tance.
In the subsequent droplet separation -the veloci-ty of the gaseous
Eluid flow is reduced enough to make the liquid drople-ts
separate and to enable them to run along -the walls of the frame
s-tructure and down to the bottom, and further through aper-
tures in the inlet connector into the inlet connector for pre-
purification of the gaseous fluid flow. In the design of the
invention in fact an energy consumption figure as low as 1 HP
per 1000 m3/hr of gaseous fluid flow to be washed is achieved.
The external disposable subatmospheric pressure will be abou-t
2000 Pa, -that is, the efficiency of -the blower means is about
74%.
The present invention will be described in detail
wi-th reference to a preferred embodiment of the invention,
depicted in
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the accompanying drawing, in which:-
The single Figure is a schematic elevational view
of an advantageous embodiment of the apparatus of the inven-
tion.
In the Figure, the apparatus of the invention
which in general is indicated by the reference numeral 10
comprises a frame s-tructure 11,12, a fluid flow inlet con-
nec-tor 13, a scrubber means 15 disposed within the frame
structure 11,12, an exit connector 14 for carrying off the
purified fluid flow, and a connector 20 for introducing
scrubbing liquid in-to the apparatus 10 and for contac-ting it
wi-th the fluid flow. In this embodiment, the gaseous fluid
flow has been disposed to flow through a pre-treatmen-t
section 19 i.nto the inlet connec-tor 13, whereby when flowing
into the means 10 -the gaseous fluid flow is already pre-
puriEied. The pretreatment sec-tion 19 may consist e.g. of a
cyclone separa-tor or a scrubbing tube or another equivalent
construction known in itself in the art Erom which the
gaseous fluid flow together with its non-abrasive impuri-
ties is conducted in a rotary motion about a vertical axis
into the inlet connector 13.
In this embodiment a blower means is used as
scrubber rneans 15, this blower means having been arranged to
be driven by a mo-tor 16. The impeller of the blower means
15 may be closed or open. In the present embodiment, the
impeller has been provided with baffles 17 for directing the
gaseous fluid flow along the vane of the blower means 15.
The motor 16 rotating the impeller has in this embodiment
been carried on the wall 11 of the frame s-tructure by media-
tion of rods 18. Between the rods 18 and the wall 11 ample
free space is left, so that the gaseous fluid flow can pass
upwardly towards the exit connector 14.
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In accordance with the fundamental concept of the
invention, the end region 21 adjacent to the scrubber means
15 of the fluid fl.ow inlet connector 13 has a diminishing
cross sec-tional diameter to the purpose of accelerating the
incoming fluid flow before the fluid flow en-ters -the scrub-
ber means 15. According to another important char-
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acteristic feature, the inlet connector 13 has been provided with
holes 22 adapted to receive the return flow of the scrubblng liquid
and to admit it into the inlet connector 13. It should be partic-
ularly noted that the holes 22 have been disposed to lie in that
area of the inlet connector 13 where no acceleration is applied to
the fluid flow.
In this embodiment, the scrubbing liquid inlet connector 20 has
been disposed to pass through the wall of the fluid ilow inlet
connector 13 and to be directed withln the inlet connector 13
towards its flow orifice pointing to the scrubber means 15.
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The mode of operation of the~4~n~ 10 of the invention is as
follows. The gaseous fluid flow pre-purified in the pretreatment
section 19 passes through the inlet connector 13 in a flow potion
rotating about a vertical axis and it is accelerated in the conical
section 21 from an initial velocity at point A about 7-12 m/s to
20-25 m/s at the point B. At this point, the scrubbing liquid is
introduced through the connector 20 into the gaseous fluid flow,
whereafter the blower means 15 accelerates the gaseous fluid flow
and the scrubbing liquid from velocity 20-25 m/s at B to 60-100 m/s
at C. By this design an extremely high scrubbing efficiency is
achieved without need to employ a blower means 15 that would re-
quire high motor power. In the droplet separation following after
the acceleration, the velocity of the gaseous fluid flow drops so
much in the cowl section 11 that the droplets will separate and are
enabled ts run down along the wall 11 to the bottom 12 and further
through the apertures 22 into the inlet connector 13.
The holes 22 in the inlet connector 13 have been shaped so that
they are adapted to direct the scrubbing fluid return flow to
rotate within the inlet connector 13 in a rotary motion with the
same sense of rotatlon as the gaseous fluld flow progressing ln
opposite direction, whereby the scrubbing fluid return flow as it
flows downward in the inlet connector 13 passes perpendiculflrly to
the upwardly flowing gaseous fluid flow and thus effects the Yost
efficient possible prescrubbing of the gaseous fluid flow within
the inlet connector 13. The downwardly flowing scrubbing IL-Iuid
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flows in this embodiment into a preseparatror, whlch possibly also
incorporates a liquid collectlon tank.
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In the~dQs~ according to the invention, the blower means lS has
been advantageously carried out so that the blower means 15 as it
accelerates the fluid flow directs part of the purlfied fluid flow
as a recycling flow back through the holes 22 in the inlet connec-
tor 13 into the inlet connector 13, whereby such a rotating fluid
flow drives the liquid droplets flung out by the blower means 15
ahead of itself towards the holes 22 and causes the scrubbing
liquid to be put in 2 rotary motion within the inlet connector 13.
In the embodiment depcited ln the figure of the drawing, the end
portion 21 adjacent to the scrubber means 15 of the inlet connector
13 is conically tapering.
The means of the invention ls not critical as regards the design
selected for the scrubber means 15. Rotary power to the impeller
may naturally be provided with an externally placed motor or by
belt transmission, or using a hydraulic motor. The motor 16 may
also be completely isolated from the gaseous fluid flow by covering
it with appropriate protective shields. It is then for instance
possible to cool the motor by an external air current. The exit
connector 14 may equally be of another kind, and it may if required
be provided e.g. with an additional droplet separator in order to
ensure the best possible droplet separation. Moreover, the conical
portion 21 of the inlet connector 13 may be replaced merely with a
constricted aperture, through which the gaseous fluid flow is
admitted to flow to the impeller of the blower means 15.
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