Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The invention relates to apparatus -for cleaning
gaseous fluids Formed by a turbine having a motor driving a
rotor, and a filter placed in the flux of fluid produced by the
turbine,
By turbine is meant any apparatus whose rotor
turning at high speed produces a centrifugation. In this
description, the word turbine is synonymous with centrifugal
ventilator,
Conv0ntional air cleaning or purifying apparatus
10 include screens of filter paper or fabric, or baskets tcorfs)
or baffles enclosing active substances in granular or liquid
form and through which air is drawn or blown, Active carbon,
beds of granular potassium permanganate and sawdust
impregnated with manganese dioxide have all been proposed as
active filtering material which retains impurities in the air by
physical or chemical action. These known cleaning apparatus
require means for strongly pulsing the air which are sufficient_
Iy powerful to overcome the head loss produc:ed during passage
of the air through the filters. The consumption of power
20 and of costly chemical products used is high and is contrary
to the efforts being made to economize power and
depletable materials. Also, the noise produced by the pulsed
air is a nuisance and cleaning and replacement of the filters
is generally a difficult and dirty operation.
An aim of the invention is to provide an apparatus
for cleaning gaseous fluids which is of simple structure,
economical, easy to service, quiet in operation, has a low
power consumption and which is capable of cleaning fluids
chemically ancl/or by sedimentary absorption of impurities.
The yaseous_fluld cleaning apparatus according to the
invention is characterized in that the filter is provided in an
absorbent material able to retain particles in suspension in
the gaseous fluid and disposed in such a manner that the flux o~
gaseous fluid produced by the turbine licks its surfaces without
passing through them, the turbine being arranged to produce
10 a flux of fluid with turbulent flow.
. In a preferred embodiment, the rotor of the
turbine is provided in said absorbent material and hence pro-
vides both a ventilating function and a cleaning function.
According to the nature of the cleaning or
purification to be carried out, the manner o-f construction of
the turbine can vary,
The turbine rotor may advantageously be made of
a woven or non-woven fibrous material and is constructed in
such a manner that when it is rotated, it produces a
20 turbulent flow of the gaseous fluid. In pre-ferred embodiments,
~- the rotor of the filtering turbine may be made:
1. o-f a pile of discs, for example of paper, separated from
one another by washers, the discs having central intake
openings and being impregnated or coated with at least one
chemical rea~ent capable of reacting with the gaseous fluid
to be cleaned;
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2 of a-t leas-t one radially~-folded disc made by placing together
the narrow ends of a rectangular sheet folded across its width
in zig-zag configuration, and which may be impregnated or non~ !
_impregnated;
3. of two discs between which are -fixed, edgewise, straight
bands or l~ands folded in zig-zag or in spiral configuration,
disposed generally radially between the discs, the bands and
discs being impregnated or non-impregnated;
4. of at least one disc on which are fixed frusto~conica
10 tubes which are juxtaposed in general radial configuration on the
disc or between the discs which is/are impregnated or non-
. -impregnated, or
5 in any other form o~ known rotors of radial turbines or
centri-fugal ventilators.
The turbine may have a stator, i, e I a casing which
surrounds the rotor, of any known forrn~ -for example: a
.i. .
simple protective grid for the rotor; a closed sheet metal
casing having at least one fluid inlet on the rotor axis and
. one or several peripheral ou tlets; or shaped volutes o-f
20 centrifugal ventilators and radial turbines, The motor driving
the filtering rotor is fixed with the stator,
As in centrifugal ventilators, the rotation of the
filtering wheel produces a displacement of the gaseous fluid
to be cleaned $rorn the centre o~ the turbine towards the
periphery, through the wheel. By virtue of the laws of fluid
mechanics, in particular whe~ the speed of flow of the fluid
through the rotor is greater than the critical speed~ the
laminar limiting layer phenomena trallsform into turbulent
limiting layer phenomena, In turbulen t flc:)w , the
speed of the -fluid at each point of the space in the rotor
undergoes continuous chanyes, both in value and direction~ This
random mixture of the fluid masses favourizes an ~xcellent
contact with the surfaces of the rotating discs. Gases to
be neutralized thus come into COntaGt with the impregnated
sur~aces and are chemically transformed J Dusts, aerosols and
10 other metarials in suspension in the gaseous fluid are deposited
in sedimentary layers on the walls of the rotor,
To increase this phenomenon of turbulence due to
the viscosity of the gaseous -fluids and to permit the fixing of
particles, the surface of the constituent material of the
filtering rotor should be rugous, i e. have visible asperities
the dimensions of which will depend on the nature of the
cleaning to be carried out.
The absorbenk material forming the turbine ( or
stator) surfaces may be a fibrous, rigid or flexible, woven
20 or agglomerated material, such as a cardboard-like material,
corrugated paper, sheets of porous or alveolar plastics
material, or any other stuck non-woven fibres (coton; poly-
`~ ester, glass, etc. ), or woven fibres.
Furthermore, the makerial with a rugous surfacemay be impregnated or coated with at least one chemical
reagent capable of reacting with polluting gases or smelly
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particles contained in thle gaseous fluid to be cleaned, and which
a~e to be removed, Such a chemical reagent will be chosen so
that when the polluting gases or smelly particles come into
contact with the impregnated or coated sur~aces of the rotor
(or stator) J it transforms them into salts which remain fixed
on the rugous sur~aces,
The absorbent material may alst~ be imPregnated with
a bacteriological agent, ~or example germicide solutions for
killing micro-organisms contained in the fluid to be cleaned~
In a preferred embodiment of the invention, the
chemical reagent is an oxidi~ing agent, in particular a perman-
ganate and~vr activated manganese dioxide, Activated MnO2 is
well known in the art; it exerts a greater and more rapid
oxidising action than ordinary MnO2, and is usually formed by
a care ful partial reduction of KMr.04 ~ It is believed that the
activated MnO2 still contains some KMnO4, It has been found
that, most surprisingly7 activated MnO2 is ~ormed quasi- :
-automatically by impregnating paper with an aqueous solution
of KMnO4~ Preferably, as material of discs of the rotor, one
20 uses cellulose which is as pure as possible" It is thought that
the cellulose acts as a reducing agent for trans~orming KMnO4
into activated MnO2~
The KMnO4/MnO2 system also has another
advantage, Since the salts of bivalent manganese ( Mn ( II ) )
which are formed when the oxidising agent is depleted are
white, this forms an indicator for the system. The decolour_
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ation thus indicates that the active material is reaching
exhaustion, and the filter is changed.
Other oxidising agents may be used for the
impregnation or coating of the discs : for example salts,
oxides or hydroxides of Fe ( III ), the chromates or bichromates
of salts of Sn ( IV ), Pb ( IV ), C e ( III ), T i ( IV ), vanadium,
etc J It is also possible to use cyano-~err ates ~ III ) and
addition composites oP H 202, for example perborates, urea
peroxide etc. These oxidising agents, including KMnC)4and
10 activated MnO2, may be used alone or mixed.
Use of an oxidising agent is preferred since the
-~most usual impurities o* air are easily oxidisable. These
impurities are, for example, H2S, SO2, solvent vapours
t alcs)hols, ketones, esters, hydrocarbons, aldehydes ), amines,
greases, mercaptans, and so on.
Some of these impurities when oxidised give acidia
products, For example, H2S and SO2 are oxidised to SO3.
Normally, these Gxidised products are retained by the material
o* the sheets, for example according to the follcwing
20 rela1;ionship:
SO3 ~ MnO ~ MnSO~I, the MnO being the product -
of the reaction
S2 + Mrl02 ~ SO3 -~ MnC),
To further increase the retaining power of the
filter, one may add to the oxidising agent with which the
rotor discs are impre~nated or coated , a base such as KOH, ~-
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NaO~, Na2CO3 or K2CO3~ It is also possible to apply the
oxidising agent to the median part of the rotor and to
impregnate or coat the periphery with the base. As a
variation, a cylindrical ~or non-cylindrical~ sheet is placed
about the rotor and the air leaving the rotor comes to hit
this sheet whic~ is impregnated with a different reagent to
that of the rotor; if it is for example impregnated with a
~ase, this sheet will thus retain the acidic products o~
oxidation.
la The discs may also be impregnated with perfùmes,
as may said cylindrical sheet if one is provide~. It is also
possi~le, if necessary or desired, to incorporate a fireproofing
agent in the treating material to avoid fire when the reaction
with the impurities ~akes place violently or when the gaseous
fluid is at a critical temperature.
The inyention is directed to an apparatus for
cleaning gaseous fluid comprising a turbine including a rotor
with a rotary disc. The disc is pleated, which moves the
gaseous fluid that contacts the rotating pleated disc. This
causes the rotor to perform a ventilatlng function. In
addition, the pleated surface of the disc is a roughened
surface having the capacity for retaining particles of
gaseous fluid. Thus, as t~e gaseous fluid is moved due
particularly to the pleated configuration of the surface
of the disc, the gaseous fluid is also filtered by the
rough surface of the pleated disc. The pleated disc is
of such material that the gas and the particle impurities
do not pass through the pleated disc, ~ut instead move
over the surface thereof.
The accompanying drawings show, by way of
example, several em~odiments of a gaseous-fluid cleaning
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apparatus according to the invention. In the drawings:
Fig~ 1 is a cross-sectional arld elevational view of
a ~irst; embodiment of gaseous~fluid cleanîng apparatus whose
rotor comprises a pile of impregnated discs forming a rnulti-
-layer ~ilter;
Fig, 2 is a plan view of the pile Q f impregnated
discs ~orming the rotor of Fig, 1;
Fig, 3 is a cross-section through a second
embodimerat of gaseous~fluid cleaning apparatus, in whi~h
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a filter is disposed concentrically about the rotor and i5
fixed to the stator;
Fig, 4 is a cross_section along line IV-IV of
Fig. 3;
Fig. S is a schematic cross-sectional view of the
rotor of a variation of the apparatus of Figs. 3 and 4;
, .
~: ~ Fig~ 6 is a cross-section of another form of
rotor, along line VI-VI of Fig. 7;
Fig. 7 is a top plan view of the rotor of Fi~. 6;
Fig. 8 is a cross-sectional view of a third
embodiment of gaseous~fluid cleaning apparatus adapted to~.
also provide a humidifying effect;
Fig. 9 is a top plan view of the cleaning_humidifying
:~ apparatus of Fig. 8;
Fig. 10 is a. schematic top plan view of a fourth
gasous-fluid clean ing apparatus comprising a rotor which acts
i as a centrifugal filter;
Fig. 11 is a side view of the rotor of the apparatus
: of Fig. 10;
Fig, 12 is a top plan view of a variation of the
rotor of the embodiment of Figs . 10 and 1 1;
Fig. 13 is a side view of the rotor of Fig, 12;
Fig, 14 is a top plan view of a fifth mbodirnent
of gaseous-fluid cleaning apparatus also comprising a rs:>tor
which acts as fil~.er;
Fig. 15 is a cross-section along line XV-XV of
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Fig , 1 4;
Fig, 16 is a partial top plan view of a variation of
the rotor o~ the embodiment of Figs, 14 and 15;
Fig, 17 is a top plan view of a sixth embodiment of
gaseous~fluid cleaning apparatus;
Fig. 18 i5 a side view of the apparatus o-f Fig~ 17;
Fig, 19 is a top plan view of a seventh ernbodirnent
of gaseous-fiuid cleaning apparatus; and
Fig, 2() is a side view o-f the apparatus shown in
10 Fig, 19.
The cleaning apparatus shown in Figs, 1 and 2
comprises a casing 1 fixed to a plate 2, the casing 1 enclosing
an electric motor 3 fixed under plate 2, A shaft 4 of motor 3
~ drives a rotor 5 disposed in a protective cover 6 which is
: open at its top to direct the expelled air upwards. The rotor
5 is ~ormed by a pile o-Ç discs o F paper pierced with openings
7 and a central hole 8 which receives the motor shaft 4. The
paper of the discs forming the rotor may be o-f natural or
synthetic fibres and is impregnated with chemical reagents,
20 usually an aqueous solution o~ KMnO4 which is dried in air
at a temperature between 20 and 50 C. The surfaces of
the discs may also be corrugated or ribbed to increase the
area in contact with the fluid.
Operation of the apparatus is as follows : when
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the motor 3 is s tarted, it turns the rotor 5 which acts as
a centrifugal wheel driving the fluid towards the exterior.
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The g~seou~; fl.lid is drawn in through the openings 7 ~nd is
driven by the discs of rotor 5 which are sufficierltly spaced
apart to allow flow of the fluid. As the -fluid approaches the
periphery of the rotor/filter, its speed increases and, as a
result, the static pressure drops ( Bernoulli I s law) so that
the discs tend to move together. The gaseous ~luid passing
between the discs is thus made to lick their surfaces, and
during this intimate contact particles of dust are removed
from the fluid by adherenc~e, and polluting gases as well as
10 polluants in the aerosol state and which are capable o$
chemical transformation are captured by catalytic or chemical
reacti~n with the reagents impregnated in the discs r
The fluid blown by the rotor 5 is then directed
upwards by the cover 6 and flows vertically upwards, whereas
in the centre of the cover a depressuriz ation is produced so
that ambient fluid is drawn in and sucked through the openings
7 of the rotor 5 ( see the arrows, Fig. 1 ) .
Of course, baffles or deflectors, not shown 7 can
be provided on the described apparatus so that the fluid
20 delivered does not mix with the fluid which is drawn in~
- Openings, not shown, can also be provided in the cover 6 for
the same purpose.
In the cleaning apparatus o~ Figs. 3 and 4, a motor
15 carries an external rotor 16, the motor 15 being fixed on
a plate 17. About the rotor 16 is sec:ured an annular support
- plate 18 on which are fixed a series of blades 19 arranged
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regularly spaced about the rotor 16, the upper ends of blades
19 being fixed to an annular plate 20. The blades 19 turn in
an opening in a pile of ~ixed rings 21 of ;mpregnated paper.
The rotor 16, blades 19 and plates 18 and 20 turn in a
volute comprising a lower chassis 22 and a removable cover 23
which enables the filter formed by the impregnated rings 21
to be fitted, The cover 23 covers the blades 19 but has a
central opening over the rotor 16 and the annular space 24
situated between the rotor 16 and the blades 19, so that
10 the f~luid to be cleaned may be sucked in at centre of ~he
ventilator, as indicated by arrows 25 ( Fig, 3) ~ This fluid is
then b30wn out by the blades 19 through the impregnated
rings 21 forming the filter, and the -forming ~luid leaves via
an outlet 26 ( Fig, 4~ and may if desired be delivered out
of the ambient zone.
3:n the apparatus of Figs. 3 and 4, the filter is
formed by a rotor with blades about which is disposed a pile
of rings of impregnated paper -fixecl to the chassis 22~ The
ventilator blades turn relative to the pile of impregnated
20 sheets and force air, for example, between these sheets.
However, the impregnated annu!ar sheets could be fixed to
the blades of the ventilator and turn with it~
Fig. 5 schematically shows a variation of the
rotor of Figs, 3 and 4, in which a motor drives a central
rotor 16 with blades 1g, as before, and sheets 28 of
impregnated paper disposed about the blades. These sheets 28
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are not perpendicular to the axis of rotation of t;he rotor, :~
but are regularly spaced parallel to this axis and are fixed on
the periphery of the rotor The sheets 28 must have a
sufficient thickness to resist bending under the action of air
expelled between the sheets by the rotor, They are held, at
their top and bottom ends, in the same manner as the rotor
blades, i ~ e . by lower and upper rings to which they are fixed. .
- As in the embodiment of Figs~ 3 and 4, the filter-
_forming sheets 28 could~ instead of turning with the rotor,
10 be fixed to the stator about the rotor blades which, as they
turn, force air to pass out ~etween the sheetsO
- T ests have been carried out with a cleaning
apparatus as described with reference to Figs. 1 and 2.
The apparatus had a rotor ~ormed of fifty discs or rings of
cellulose paper steeped with KMnO4 and dried. The apparatus
was firstly placed in an atmosphere strongly polluted with
H2S and then, after changing the rotor/filter, in an
atmosphere polluted with SO2. The results were as follows:
A ) Concentration o~ H2S before
the test 32. 4 ppm
concentration of H2S after
the test 6. 09 ppm
efficiency 81. 2 %
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B ) Test 1 Test ~_
concentration of SO2 before
the test 112 ppb 284 ppb
concentration o~ SO2 after
the test 20 ppb 6~ ppb
efficiency 82 % 76 %
( ppm = parts per million; ppb parts per billion ) O
The above-described apparatus are particularly
suitable for cleaning gaseous fluids by chemical meansO The
10 described chGmical impregnation of, for example, the discs
may be adapted to the types of gas to be neutralized. The
rotor construction may comprise alternate discs impregnated
with dif~erent che mical agents, for e:cample a metallic oxidising
agent impregnating the even sheets and a base impregnating
the odd sheets,
The -Pilter pile may also be forrned of semi-rigid
sheets of rugous or alveolar material for capturing dusts g
separated by thinner flexible discs impregnated with at least
one chemical reagent which reacts with the polluting gases
20 of the fluid to be cleaned.
The filtering rotor 30 shown in Figs~ 6 and 7
comprises several semi- rigid discs 32, each adjacent pair of
cliscs 32 being separated by thin discs 33 of smaller diameter.
The discs ~2 are formed s)f thiclc rugous paper, for example
of blotting paper, and the discs 33 are of thin crepe paper
impregnated or coated with an appropriate chemical reagent~
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The combination of these two materials, one thick
andnaturally rugous and the other thin and impregnated with a
chemical reagent, separated by spacers 34, gives this
filtering rotor a maxirnum e-fficiency both for the mechaniGal
( i, e, sedimentary~ filtering and the cherrlical f;ltering, and
enables a high air flow for a slow speed of rotation~
The discs 32 and 33 as well as spacers 34 are
fixed on a central shaft ~5 driven by a motor, not shown,
The all;ernating pile of discs 32 and 33 has p~r~orations 36
10 ~or the in take of air to be ~iltered,
The speed of rotation of the multi-layer rotor of
Figs. 6 and 7 is preferably chosen to provide a turbulent
flow of the gaseous -fluid between the discs.
An additional neutralization of gases or odours may
be obtained:
- by placing a chemically treated or perfumed
ring 38 acljacent the rotor intake;
- by placing in the ~ilter one or more chemically
treated or per-fumed discs, not shown; or
~0 - by placing about the filtering rotor, in the range
of ejection of the cleaned fluid, a chemically treated or
perfumed ring 39.
In principle~ there are no dimensional limits for the
various above-described multi-layer filters.
The embodiment shown in Figs, 8 and 9 is designed
to operate as a cleaning apparatus and as a humidificator of
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a gaseous f`luid, notably air. It comprises a casing 40 closed
by a cover 41 having a oentral intake opening 42. At the upper
part of ca~ing 40 adjacent cover 41 are slots 43 serving as
air outlet openings. In its lower part, the casing 40 has a
central recess 44 housing a motor 45 whose shaft 46 passes
through the casing 40, Between the shaf-t 46 and the upper
part; of recess 44 is disposed a lip-joint 47 making the casing
40 fluid-tight, the }ower part of casing 40 ( i, e, about recess
44 ~ being filled with water. On the motor sha-~t 46 is fixedly
10 mounted a support disc 48 on which is placed an interchanseable
multi-layer ~ilter 49 ~ormed of a pile of porous sheets 50
separated from one another by central spacing washers 51.
l'he multi~layer filter 49 is pressed against the support disc
48 by means of a washer 53 held by a screw 52 screwed i
the shaft 46. The fi!ter 49 has ~our suct;ion holes 54 disposed
adjacent to and regularly spaced about the shaft 46 facing the
intake opening 42.
In the path of ~he intake curren t, represented by
- arrows 55 9 and facing the holes 54, are placed two suction_
20 ~operating nozzles 56 supplied with water by tubes 57 passing
under the cover 41 and extending along the lateral walls o~
casing 40 into the water in the bottom of the casing, The
noæzles 56 are arranged so that when the multi-layer filter
49 rotates and draws aîr in through the opening 42 ( thîs air
then flowin~ between the sheets 50 and leaving by the slots ~:
43 ), a part o~ this air passes through the nozzles 56 and
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sucks water through the tubes 57, -this water being vapourized
on the multi_layer filter 49 which is thus uniformly humidi~ied.
If the speed of the flux of air sucked into the
humidifier of Figs. 8 and 9 is too low to ensure corrcct
operation of the nozzles 56, a water supply pump (not shown)
could be connected to the pipes 57, or humidificat ion of the
filter could be provided by vapourization o~ liquid on the filter
by means of a spray.
The embodiment of F~igs. 8 and 9 may comprise an
10 overflow orifice, or a safety device, not shown, to prevent
the apparatus being started if the level of water in the casing
40 should be too high, e, g, reaching the multi-layer filter.
Also, the apparatus of Figs, 8 and 9 may be connected to a
hygrostat, not shown, which automatically controls operation.
- The multi-layer filter may also be treated chemically or
baoteriologically to kill all living germs and neutralize odors or
toxic oomponents of air. Alternatively~ the chemical or
bacteriological products may be added ko the water instead
of being direc tly applied to the shee ts of the multi layer
20 filter,
In a preferred form, the interchangeable multi~
-layer filter of the apparatus of Figs. 8 ard 9 has a diameter
of 31:)0 mm ancl a height of 50 mm, and contains 50 sheets of
- newsprint paper, representing a filtering sur~ace of 5 m2O
This filtering surface~ is three to ten times greater th0n
the filtering surface of comparable known humidificator
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The apparatus is provided wikh a 60 W motor able to drive
the multi-layer -filter at speeds of -from 500 to 2000 r. p. m.
With an apparatus having the mentioned technical
specification, the following air-flow rates have been obtained:
- air-flow rate at 500 r p. m. : :150 m /h
air-flow rate at 900 rc p. m. : 250 m3/
The water reservoir of the apparatus should
contain at least 15 litres~ which allows normal operation for
about 24 hours at an arnbient temperature of 20C~
As mentioned above, the sheets of the multi-layer
filter are of newsprint paper, or could alternatively be crepe
~; or corrugated paper. Newsprint sheets have the required
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porosity and a sufficient meohanical strength to withstand
rotation at speeds up to 2000 r p m. It is however evident ~;
that these newsprint sheets may be replaced by sheets o~ -
other n~.aterials having a suffiGient porosity, for example
blotting paper, sheets of porous plastics materials, sheets
formed of compressed fibres c~overed with mineral materials,
etc.
It has been observed that a multi-layer filter made ;
of sin~ple sl~eets of rugous paper adequately stops all ~`
particles in suspension in the air, notably smoke, pollen,
dusts and aerosols . B acteria contained ~ the air are in
general aiways carried by dust or other carriers. As dust
particles are stopped by the filter, the latter has an air-
purifying effect and may deliver practically sterile air.
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The sheets composing the filter may be chemically
or bacteriologically treated to kill all harmful germs contained
in the air. They may thus be steeped with bacteriological
products or ger~rlicides, as well as perfumes of all types,
Also, ~s previously mentioned, the sheets of the multi-layer
filter may be chemically treated to neutralize odours or toxic
gases contained in the gaseous fluid to be cleaned,
The multi~layer filter of Figs, 8 and 9 provides
an almost perf0ct purification of the gaseous fluids it mixes,
10 In addition to its purilFication function, the multi-layer ~ilter
also carries out two ~urther functions:
~ a humidification function, which is very ef-Çicient
in view of the humid surface area, For a flow of about
150 m3/h, it produces an evaportion of water between 4 and
~ dl per hour, according to the humidity of the air taken in
and its temperature; and
- a rotor function, which enables it to develop a
- greater manometric pressure than a helicoidal wheel o-f the
same diameter, and enables it to produce, for a diameter of
20 300 mm, of -Çlow of 250 m3/h for a speed of rotation oÇ
900 r, p, mO
The gaseous-fluid cleaning apparatus shown in
Figs, 10 and 11 comprises a rotor 61 arran~ed to operate,
without a casing, in a gaseous fluid to be cleaned, The rotor
61 is in the form of a pleated disc IFixed on a shaft 62 by
means of upper and ~ower securing washers 63 and 64, Shaft
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62 is driven by a rnotor, not shown, The disc 61 iS made
simply from a rec-tangular band o~ thin material wikh a rugous
or alveolar sur-face which is ~olded across its width and the
two ends joined together edge-to-eclge, to ~orm a radially
pleated ring with a central opening through which the shaft 62
passes, The securing washers 63, 64 may be simple friction
washers fitted on the shaPt 62, or may be secured by screws,
not shown, The disc 61 may be assembled ~o the sha~t 62,
and possibly to the washers 63 and 64, by an adhesive,
The apparatus of Figs, 10 and 11 is particularly
suitable for cleaning air since such an apparakus with a multi-
-folded rotor operating in an enclosure such as a room
produces a circulation of air in the enclosure with the apparatus
as point of convergence, This natural suction of the ambient
air through the apparatus kakes place silently, since even at
slow speeds of rotation, there is a great flow of air through
the apparatusO The pleated disc 61 perfectly functions as
rotor and filter, The flc>w of air produced by a disc 61 of
40() mm external diameter rotating at 200 r. p, m, is of the
order of 300 m3/h per face of the disc, or 600 m3Jh -for the
two faces of khe pleated rotor, At this very low speed of
rotation, the apparatus makes no noise, The 400 mm diamelcer
disc with which the above-quoted flow measurements were
carried out was made of a cellulose paper about 1 mm thi¢k,
and fs~lded to provide a diso thickn~ss of 3 to 4 cm.
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~/hen -the apparatus of Figs. 10 and 11 is used to
purify air containing pulluting gases (H2S or SO2 for
example~, the pleated disc 61 may be impregnated or coated
with an appropria-te chemical reagent, according to the
polluting gas to be remo~ed, as previously described for the
multi-layer ~ilters.
The disc 61 may, as previously mentioned, be
impregnated with per~umes or germicides, Also, the apparatus
of Fig 10 can be arranged to act as an air humidi~ier, by
10 imbibing the disc 61 with water. This can be achieved in a
simple manner, for example by directing a jet o-~ water
against the disc or by making the rotor shaft of a porous
material and placing it in contact with water in, ~or example,
a tank.
Figs. 12 and ~3 show a variation comprising three
- discs 65, 66 and 67 similar to the disc 61 of Fig. 10,
s~ported and spaced apart by flat circular sheets 68, 69, 70
~; and 71 ( Fig. 13) formed of a similar material to the pleated
disc:s 65 to 67. The fs~lding of discs 65 to 67 is arranged to
20 leave a central hole 72 and the sheets 68, 69 and 70 have like
circular holes positioned 50 that when the rotor is rotated,
air is drawn into the centre of the turbine and, as indicated
by arrows 73, Fig, 13, passes through hole 72 and flows
out between channels ~ormed by the pleats of the three
discs 65, 66 and 67 and the sheets 68, 69, 70 and 71. The
bottom sheet 71 has a srnaller central opening than the other
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sheets, to receive the driving shaft 74 of a motor, not
shown. Sheet 71 is secured to the shaft 74 by two washers
75, 76, The rotor formed by the pleated discs 65 to 67 and
sheets 68 to 71 may be assembled by an adhesive, by rivetting,
etc
The sheet material used to make the turbine of
Figs . 12 and 13 is the same as that described for the
embodiment of Figs. 10 and 11~ and may be subjected to the
same treatments.
The rotor of Figs. 12 and 13 may advantageously
be enclosed in a casing, for example a cylindrical or volute~
.shaped casing with a central intake and radial or tangential
outlet .
The embodiment shown in Figs. 1~ and 15 comprises
a rotor 77 having lower and upper annular sheets 78 and 79
spaced apart by radially-directed bands 80 regularly spaced
$rom one another around the circumference, The sheets 78,
79 and bands 80may, as for the components of Figs. 12 and
13, be assembled by an adhesive when they are formed s~f
20 paper or of an agglomerate of woven or non-woven fibres.
If the rotor is made o-f semi-rigid alveolar plastics material,
it may for example be assembled by heat welding~ However,
it will be apparent to persons skilled in the art that the
rotors of all of the described embodiments can be assembled
by any known means, such as stapling~ rivetting, point
assernbly, sewing, et~.~
.
_ 22 -
.
The assembled rotor 77 is held between two
circular flanges 81 and 82 secured on a shaft 83 of a motor
not shown, the two flanges having air-intake openings 84
When the rotor 77 is rotated, the gaseous fluid drawn in
through the openings 84 flows out through radial channels
defined by the lo~ver and upper sheets 78, 79 and bands 80,
As for the preceding embodiment, the rokor 77 may be
enclosed in a casing, not shown, with ~entral intake openings
through which foul gaseous -fluids to be cleaned is drawn in
or delivered through a pipe, and one or several lateral outlets
through which the purified gaseous fluid can be delivex-ed to a
given location.
In the variation of Fig. 16, the planar bands 80
of rotor 77 of the embodiment of Figs. 14 and 15 are
replaced by generally radially disposed bands 80a folded in
zig-zag configuration to make the fluid undergo ohanges of
direction which will bring the particles in suspension, or the
gas particles to be removed, into contact with the walls of
the folded bands 80a,
The rotor 85 shown in Figs, 17 and 18 has lower
and upper annular sheets 86, 87 held between two .fianges 88,
89 fixed on a shaPt 90 of a motor, not shown. Between
the sheets 86, 87 extend bands 91 in the configuration of
spirals regularly spaced about, and diverging from, the
flanges 88, 89 which are identical to the flanges 81, 82 of
the embodiment of Figs. 14 and 15. The rotor 85 is made
- 23 _
in the same ananner and wikh the same ma-terials as described
with reference to Figs. 10 to 15.
In the embodimen t o-f Figs . 19 and 20, the rotor
101 also c~mprises two annular sheets 102, 103 between
which are radially disposed frusto-cvnical tubes 104 of the
same material as sheets 102, 103 Assembly is, as in the
preceding embodiments, by an adhesive or other known means
such as stapling, rivetting, sewing e tc O The thus~-forrned
rotor is held between two flanges 105, 106 on a shaft 107
10 of a motor, not shown.
The bands 80, 80a of Figs. 14 to 16, bands 91
of Figs. 17, 18 and tubes 104 o~ Figs. 19, 20 may, in
variations not shown, be disposed in the ~orm o-f deflector
blades fixed in a single annular clisc 78 or 79, 86 or 87, 102 ~`
or 103, according to the known techniques of constructing
the rotors or turbines of centrifugal ventilators.
All the described embodiments operate in the
same manner, The gas flows through the rotors with a
turbulent -flow. With such a turbulent flow, the particles
20 in suspension or particles of unwanted gases to be fixed,
in the case where the rotor is treated wi th a chemical
reagent, have the greatest possibility of being retained on
the ru~ous sur~aces of the turbine. It is also clear that
several rotors of any o~ $he types shown in FigsO 12 ^to
20 can be assembled to form a ~mit with sP.veral stages 3 as
illustrated ~or 1;he embodirnent of Figs. 12 and 13, and the
24 --
r~-tor~i can be erlclosed in a casing wit~h air intake and outlet
orifices, or can be unencased~
Of course, the described filters are interchangeable
and may even be cleaned for re-use, Their cost price is
moderate. The material of which they consîst may be treated
chemically, for example coated with activated manganese dioxide,
alone or containing potassium permanganate c>r a basic
substance able to retain acidic products of oxidation oP the
impurities. They may alsc> be coated wi-th perfums or
10 bacteriological agents. It will be understood that the rnaterials
may be coated with not one but several chemical reagents,
each chosen as a function o-P the gaseous component it must
retain .
, ~ A fixed cylindrical or frusto_conical body may be
placed about the rotor of the apparatus to upwardly and/or
~' downwardly deviate the current of gase,ous fluid produced by
the turbine. Such a body may have at least one chemical ~'
reagent able to react wlth and retain the products o~
reaction of the impurities which pass out of the Pilter, or
20 may be impregnated or coated with a perfume and/or
impregnated with a germicide~ It may also be imbibed with
water to humidify the puri-Fied air which leaves the rotor.
Alternatively, such a body may be a cooled metal surface
which dries purified air leaving the periphery of the filter
unit by condensing water on the cold surface.
~, Persons slcilled in the art will realize that many
3~
types of turbines other than those shown in Figs, 1 to 20
can be used . The invention, in its broader aspects 9 iS thus
not limited to the described cleaning apparatus, but in
particular, according to one aspect, concerns cleaning
apparatus fitted with all types o~ turbines pro~ided of a
material with a rugous surface adapted to retain particl~s in
suspension in a gaseous fluid driven by the turbine, which
thus carries out two -~unctions, a ven tilation function and a
cleaning or purifying functionO Finally, of course, all of
10 the described cleaning apparatus can ~ as described for the
embodiment of Figs, 8 and 9, be transformed to also act as
a humidifier.
_ ~6
