Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to meth~d and means for inhibiting the
adherence of particulate matter in a confined line.
There is a long-standing problem concerning atmDspheric pollution
caused by emission of sulfur dioxide from industrial plants such as, for ex-
ample, pawer plants and metallurgical smelters.
To accc~plish the air pollution abatement, virtually all of the
technology involves the scrubbing of the noxious gases with an aqueous media.
While water alone as a scrubbing medium will remDve particulate matter and
sulfur dioxide, the presence of sulfur dioxide and other acidic materials in
the gases to be scrubbed necessitates the addition of neutralizing substance
such as, for example, lime, or any caustic substance, to the aqueous scrub,
bing medium. The use of such chemical reagents in the aqueous scrubbing
medium gives rise to the formation of chemical precipitates which, possibly
augmented by particulate matter already present in the gas stream and aque-
ous sCru~'Ding m~edium, cause deposits commDnly kncwn as "scale" to adhere to
the internal surface of the gas scrubbing apparatus. Such deposits may
accumNlate until the apparatus becomes clogged to an inoperable state and
must be cleaned out. ~
Furthermore, mDst heretofore proposed and used gas scrubkers are t
¦ 20 in vertical stacks and have several consequent disadvantages. For example,
the flow of the aqueous cleaning media through the stack is subject to the
vagaries of gravitational influence because such solutions are fed from, at,
or near the top of the stack and flow to the bottom. In many instances,
there is inadequate retention time for the solution and insufficient con-
tact between the downwardly flowing solution
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and upwardly flowing gas whereby the desixed chemical reaction is not ob-
tained. In addition the agueous solution may be caught in~the surge of
the flowing gases and blown upwardly to the emission point which re~uires
additional and expensive e~uipment to contain the aqueous solution ~ithin
the stack and to clean the deposits.
Very little, if any, provision has been made in kncwn scrubbers
to effect an initimate contact or inter nux m g between the aqueous cleaning
media and the noxious gases. These fluids are instead permitted to pass
in a flow countercurrent to each other and do not attain the desired chemi~
10 cal reactiOns~
An object of a main aspect of this invention is to provide means
which are substa~tially self-cleaning and substantially inhibit any caking
or formation of scale in the interior of the pipeline.
An object of another aspect of this invention is to provide means
which would cause the gases to flcw through a tortuous path and internux
the gases with the aqueous media to effect a total chemical reaction there-
between. r
The invention in one of its aspects ccmprises means which will
move within a substantially horizontal rotatinq confined line such as, for
20 example, a pipeline to contact virtually the entire periphery of the in-
terior of the line a's the fluids, viz. the gas and liquid media, flow
through the line. It has been found that these results can be obtained by
the use of substantially solid objects placed within the line which tumble
and bounce to cause a wiping effect and prevent caking or the formation of
scale. As the solid objects bounce and tumble, the liquid nedia is not
permitted to dry but is instead maintained in a liquid phase slurry form
and is spread around the
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entire interior periphery of the pipeline itself.
While chains, cables, wires or an~ other tumbling media may be
used, hereinafter the invention will be described specifically with refer-
ence to suspended chains, cables or ropes within the interior of the line.
It is to be understood, however, that the description is in no way intended
to limit the scope of the invention to the particular tumblers described.
As to the specific illustrative form of the invention, a cage is
provided o~mprising horizontally éxtending cross bars which are secured at
the ends and at other points therebetween to hoops. The chains, which are
longer than the distance between one hoop and another, are suspended be-
tween adjacent hoops and form hanging extended portions or loops. The en-
tire cage assemblage is then disposed within and attached to the interior
of a horizontal pipeline which is located between the noxious gas-producing
facility and the exit port for the gases.
The pipeline and the cage'contained therein are rotated by any
suitable driving means. An aqueous cleansing solution which is preferably
of a lime base or any other suitable aIkaline means, is introduced into the
pipeline~
As the pipeline and cage rotate, the chains tumble and ~ounce
across substantially the entire inner periphery of the pipeline through
which flows the fluids, namely, the gases and aqueous solution. m is
action provides a self-cleaning arrangement in which the pipeline is
thoroughly cleansed to inhibit buildup of scale or caking due not only to
the wiping action but also because the actual splashing and stirring of
: the aqueous solution maintains the same in a liquid phase. me kouncing
and
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tumbling of the chains cause them to be maintaine~ in a clean uncoated
state.
In addition, as the tumbling means pass through the aqueous
cleaning solution, it ig thoroughly wetted and carries the aqueous solution
from the bottcm of the interior of the pipeline to all points around the
periphery directly in the line of flc~l of gases. EorthermDre, the gases are
caused to flow through a tortuous path and contact is established between
the gases and the aqueous cleaning media. m e result is that a virtually
complete chemical reaction is obtained and the gases are substantially conr
pletely scrukbed. The aqueous cleaning ~edia, such as lime, flows from the
cage area and may then be either recycled or pr w essed to reclaim any
valuable chemical contents.
In accordance with the invention, the pipeline and cage are dis-
posed on a substantially horizontal plane with a very low profile to ex-
pedite assemblage, maintenance and repair. The gases are moved through
the horizontal self-cleaning area by either induced or forced draft and the
aqueous cleansing media may be passed through the chain area concurrently
or oountercurrently to the direction of the flow of gases.
; To facilitate an understanding of the invention as set forth
in one ~mbodiment thereof, reference is made to the following description
and the illustrative drawings in which:
Fig. 1 is a isometric view of the self-cleaning cage structure
having the tumbling media in suspended fonm.
Fig. 2 is an end view of the cage structu~e attached within a
rotating pipeline.
Fig. 3 i~ an end view of the cage within the pipeline
,;
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1043543
with the tumbling media in an active po~ition during rotation.
Fig. 4 is a sectional view of the pipeline showing another ~orm
of attachment of the tu~bling media and the entrance and oxit ports for
the fluids.
Fig. 5 is a perspective view of a form of cross bar used in an
aspect of the present invention.
As shawn in the drawings, a cage 10 comprises horizontally ex-
tending cross bars 11 secured intermediate and at their ends to hoops 12.
While four cross bars and nine hoops are illustrated it will be understood
that a grea~ter or lesser number may be used, depending upon the conditions
of operation. m e tumbling ~edia in the form of chains 13 are attached to
and suspend from the hoops, as illustrated in Figs. 1, 2 and 3. The
chains are of greater length than the distance between their fastening
points and, consequently, pro~ide loops or extended portions 14. The
entire cage structure is then inserted and attached by any suitable means
to the interior of a substantially horizontal pipeline 15. The pipeline
15 extends between the noxious gas-producing facility and the point where
the gases are emitted into the atmosphere.
As shawn in Fig. 4, the noxious gases 16 pass through the pipe-
line 15 from the entry port 17 to the exit port 18. The gases are caused
to flow by any well-kncwn neans (not shown) either in a forced or induced
draft m3nner.
An aqueous cleaning solution 19, which is preferably a solution
of lime, is m troduced fron the entrance 20 and passes thr3ugh the line 15
to the exit 21. The flow of the aqueous solution is shown in Fig. 4 as
; being concurrent with the flaw of the gases, hcwever,, of oourse, the solu-
tion may flow oountercurr~ntly to the flow of gases.
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While the fluids comprising gases 16 and an aqueous solution 19
pass through the lLne 15, the line 15 and the entire cage assembly 10 are
rotated at any desirable speed by a motor 22.
As the line 15 rotates, the suspended chains are bounced and
tumbled around the periphery of the interior wall 23. As shswn in Fig. 3
contact-is made over substantially the entire wall of the pipeline. This
action maintains the aqueous solution and particulate matter in a wet
phase slurry fonm and completely inhibits any buildup of scale or caking.
FurthermDre, the tumbling action and contact with the interior wall 23
maintains the chains of the entire assemblage in a clean un~oated condition.
As shown in Fig. 3, as the chains tu~ble and bounce they splash
and distribute the àqueous solution dispersing it throughout the entire
interior of the line 15. The splashing action causes droplets 24 to form,
not only wetting the entire interior of the line, but also making sub-
stantially oomplete contact with the gases 16 passing through the line.
m us, a substantially complete chemical reaction between the aqueous clean-
ing solution and the gases is effected whereby the gases are completely r
scrubbed prior to their emission at exit port 18.
As shown in Fig. 4, the chains may be suspended in another fashion,
20 that is, from one hoop 12 to another in a catenary configuration. Similar
results to those above described are obtained with this construction.
Tb accomplish the maintenance of the aqueous media in slurry
form, the cross bars themselves may have the configuration shown in Fig. 5,
that is, to form a scoop 25. This scoop disperses and distributes the
aqueous solution throughout the
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entire interior periphery of the line an~ causes the liquid to remain in
wet phase to inhibit any caking or scaling. The liquid is captured within
the scoop 25 and carried up to be dispersed during the travel of the cross
bar 11. The mixing of the liquid is continuous and this action also
carries the liquid into the path of the flowing gases which are then
thoroughly cleansed.
In addition, the cross bars7 if desired, may have flat bar por-
tions 26 toward the end of the line 15 approaching the exit ports. This r
construction provides a highly beneficial demisting effect at this place
in the pipeline 15, thereby overcoming still another major problem of here-
tofore-knonw scrubbers.
The low profile of the horizontal line 15 enables it to be easily
assembled and the unit of an aspect of this invention is the entire cleaning
area between the point of entry of the noxious gases and their exit points.
m e substantially norizontal arrangement and low profile also provide for
simple maintenance and replacement of parts.
The noxious gases which have been thoroughly cleaned will emit
at exit point 18 without virtually any pollutants. FurthRrmDre, the reacted
aqueous solution which is preferably of a lime base may be recaptured
through the exit 21 and either recycled or, by known n~ans, any valuable
mdnerals contained therein may be reclaimed.
Thus, the present invention provides a highly efficient self-
cleaning structure which, in addition to totally scrubbing the gases, also
prevents to a substantial extent caking or the buildup of scale deposits.
104;~54~
While the invention has been described in detail with reference
to one ~mbodimEnt thereof, it is to be understood that the concept encomr
passes tumbling self-cleaning media of any desired shape or form which are
provided within the interior of the line to effect the aforestated results.
The tenm "substantially horizontal", as used herein, is intended to encomr
pass various angular dispositions of the line between the entrance and exit
ports.
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