Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Apparatus for removal o~ solid ancl/or gaseous
components present in a yaseous ~luid :elow.
The present inven-tion concerns apparatus for removal
of solid and gaseous components present in a gaseous fluid flow.
Gas flows oEten contain large amounts of solids and, in
addition, e.g. sulphur dioxide or other gaseous components which
are harmEul to the environment or which one desires for other
reasons to recover from the fluid flow. The solid coarser compon-
ents can easily be separated e.g. with the aid of cyclone
separators, of which numerous different designs are known in the
prior art. It is possible with certain cyclone separa~ors to
achieve a very high separating efficiency, but yaseous components
cannot be separated by such cyclone separators.
It follows that as regards gaseous components, wet
washing is quite often the only possible way by which they can
be separated from the fluid flow. sut wet washers often do not
tolerate any high solid ma-tter loading, and on the other hand
the solids may be valuable expressly in dry state, whereby wet
washing alone is not always the best possible way to puri.fy a
gas flow. Therefore in the separation o certain components
rom a fluid flow one often encounters in the separating apparatus
the combination of a cyclone separator followed by wet washing,
hoth separation steps taking place in an apparatus of their own.
Therefore apparatus following these lines has a large siæe and
requires considerable amounts of energy because both steps have
their own pre.ssure losses. Leakages of gas, the wear and tear
of the apparatus and difficulties caused by the temperatures of
the gas are often drawbacks which have been encountered in prior :
art apparatus.
Attempts have been made to eliminate the drawbacks of
the combination constituted by a separate cyclone separator and ~.
a separate wet washer, and nowadays dry filters are commonly
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used expressly in orcler to sepclrdte mc~chanical dust. In dry
filters a suitable constructi.on may be employed to conduc-t both
the coarse and the fine solid components to -the separating unit.
However, it is impossible in dry filters to separate the gaseous
components from the fluid flow; therefore with regard -to these
components a separate wet washing process is necessary.
The invention seeks -to provide a combined apparatus
for the removal of both solid and gaseous components in a gas
flow.
According -to the present i.nvention, there :is provided
an apparatus for cleaning a gas flow to remove possible solid and
gaseous components, comprising a cyclone separator for removal of
coarser solid componen-ts from the gas flow a cen-tral exi-t tube
arranged at -the centre of the cyclone separator and housing wet
washing apparatus to remove finer solid and gaseous componen-ts
present in the gas flow and a collecting funnel arranged below
the central tube into which funnel sludge formed by removal of
the finer sol.id and gaseous components may f:low.
The inven-tion will now be described further, by way of
example, with reference to the accompanying drawing, which shows
schematically an apparatus of the invention.
Referring to the drawing, the apparatus oE the inven-
tion comprises a cycl.one separator 10, having an intake duct 12
for the incoming gas flow 11, a central tube 16, and an exit 14
for the cleaned gas flow 13.
The cyclone separator 10 comprises a conical lower part
15. The cyclone separator 10 may alternatively be of any otner
known cyclone separator construction. The incoming gas flow 11
is set into rotary, downwardly directed centrifugal motion about
~ the central tube 16, whereby the coarser solid components are
carried to the outer circumference of the gas flow in rotation
and they are separated on the shell wall of the cyclone
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10 and Eur-ther se~tle into the conical lower part 15, on the bot-
tom of which they accumula-te. The lower cone 15 of the cyclone
separator 10 may have at its bottom a suitable draining device
22, through which the separa-ted dry solid matter outflow 23 is
recovered.
The finer solid components present in the gas flow 11
and the gaseous components, however, are not separated from the
gas flow and they enter the central tube 16 of the cyclone 10,
which is open at its lower end. Into the central tube 16 the ~
washing liquid (not depicted) is fed preferably in such a manner
that within the central tube there is a powerfully distributed
washing liquid spray lying in a horizontal plane, with the result
that the gas flow entering the central tube 16 is subjected to
powerful li.quid washing, whereby the fine solid particles and the
gas components are wet and descend along the walls of the central
tube 16 in the form o~f sludge. The wet washer disposed within
the central tube 16 of the cyclone separator 10 may be designed
e.g. as taught by the same applicant's Canadian Patent Applica-
tion No. ~59,317 filedon even dateherewith. In this application a
smallblower lyingwithin the tube 16 andacting as a dropletsepara-
tor and.a larger blower arranged outside the tube 16 are rotat-
able by a common shaft. The two blowers communicate through a
connecting tube passing through the wall of tube 16 and the whole
arrangement i~ schematically indicated by the bloc~ 17 in the
drawing. By such a design a highly efficient droplet separation
is achieved, with the consequence that the outflow 13 is purified
both of the finest solid components and of gas components, and in
addition the gas flow has also been dried to be free of washing
liquid.
In order to pre~ent the sludge flowing down~ardly from
the central tube 16 from entering the conical lower part 15 of
the cyclone separator 10, where it would join the dry solid matter
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accumulated -there, a collecting funnel 18 is placed below the
central tube 16 concentrically therewith, and the said sludge
flows into this funnel. The collecting funnel 18 has a conical
part 19 and a tubular part 20, which leads out from the cyclone
separator 10~ Thus the sludge separated by wet washing can
be recovered as a separate outflow 21. The collecting funnel
18 is advantageously such that the clistance h between it and
the central tube 16 is adjustable. As regards its diameter, the
collecting funnel 18 is advantayeously a little larger than the
$ 10 diameter of the central tube ~, but it may e~ually have a diameter
equal to or smaller than that of the central tube 16 because
in the free space between the central tube 16 and the collectiny
funnel 18 the sludge is guided towards the central part of the
collecting funnel 18, forced by the~ flow directed into said
central tube 16, which causes contraction of the sludge flow
instead of its spreading onto the shell walls of the cyclone
separator 10. The collecting funnel 18 is also preferably
supported by means of bracing elements 24, carried by the conical
lower part 15 of the cyclone separator 10. It is understood that
other arrangements are equally possible for this supporting
within the cyclone separator 10.
By means of apparatus according to the invention it is
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possible from the ~*~ flow to separate within the cyclone
separator 10 both the dry solid matter and the sludge separated
by wet washing to constitute a separate outflow 23 and 21,
respectively, without necessity of using one device for the dry
separation and another separate device for the wet separation.
At the same time in the apparatus of the invention considerable
pressure losses have been avoided, which are usually incurred
when separate dry separation and wet separation are employed.
It is furthermore possible within the described
apparatus to take care of the corrosion problems in a simple
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way in those cases in which the components separated by wet
washing give rise to corrosion in the separa-ting unit. ~rhe parts
resistant to corrosion may be limi-ted to cornprise only -the cent-
ral tube 16 and the collecting funnel 18, because sludye causing
corrosion cannot en-ter any other parts of the device.
It will be appreciated that many modifica-tions may be
imparted into the described apparatus. The wet-ting of the gas
flow within the central tube rnay be arranged in several different
ways, and the distance between the central tube and the collec-t-
ing funnel, as well as -the ratio oE the diameters of -these parts,
depends on the particular application. The placement of the
central tube and of the collecting funnel wi-thin the cyclone
may var~.
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