Valmet Symflo D Headbox, 8.4 Meter – SOLD!

DimensioningofHeadboxFlows
Slicewidth8220mm323.6in
Wirewidth8400mm331in
DesignSpeed1524m/min5000ft/min
Sliceflow1644l/s200l/s/m
26080gal/min80gal/min/in

 Papergradesandfurnish
Papergrades
LWC
Basisweightrange/(basesheet)
min.37g/m2(25lbs/3300sq.ft.)
max.52g/m2(35lbs/3300sq.ft.)
Mostcommonbasisweight(basesheet)
39.2g/m2(26.5lbs/3300sqft)
Basisweightrange/(coated)
min.53g/m2(36lbs/3300sq.ft.)
max.74g/m2(50lbs/3300sq.ft.)
Mostcommonbasisweight(coated)
59g/m2(40lbs/3300sqft)

 Numberofcoatinglayers
1pce/side
Furnishcomposition(max/min)in
bone-drypaper
TMP52%
KRAFT48%

 DIMENSIONINGBASIS
Theheadboxisdimensionedmechanicallyforthepressurecorrespondingtothe
processdesignspeedofthemachine,1219m/min(4000fpm).
Theinletpiping,equalizingchamberandturbulencegeneratoraredimensioned
accordingtothesliceflow.
INLETPIPING
One-sidedstockinletwithtubebank;inletheaderrecirculationmaximum10%ofthe
sliceflow.
Design(Drawings)forthe"transitionpipe"toreplaceexistingattenuatorisincluded.
PipebyWeyco
OVERFLOWFROMATTENUATOR
Maximum3%ofthesliceflow.

HEADBOXDESIGNANDMATERIALS
GENERALDESIGN
Theheadboxconsistsoftheinletpiping,equalizingchamber,turbulencegeneratorand
slicesectionassembledbyboltedjoints.
AllsurfacesincontactwithstockareofstainlesssteelSS2343(AISI316L-type).The
supportstructuresareofsteel.Toeliminatesoiling,thesurfacesincontactwithstock
areelectropolishedormachinedbyabrasiveflow.

 GabFormerconvertible(4/6)
INLETPIPING
Thestockisdistributedthroughaone-sidedinletheaderandtubebank.Atoneendof
theinletheader,aprovisionhasbeenmadefor10%recirculation,whichenablesthe
balancingofpressureintheheader.Theheaderisequippedwithinspectionopenings
andasightglassforadjustingtherecirculation.
BASISWEIGHTPROFILEWITHDILUTIONWATER

 EQUALIZINGCHAMBER
Anequalizingchamberissituatedbetweenthetubebankandtheturbulencegenerator
forequalizingtheflowfromtheinletheader.Theequalizingchamberhashingeddoors
atbothends.
ATTENUATINGTANK
Theequalizingchamberopenstoanoverflowthresholdwhichisdesignedtodampen
thepressurepulsationsinthestockflow.Theoverflowthresholdisconnectedtoan
attenuationtank.Thestockflowingoverthisthresholdisdischargedthroughbothends
ofthechamber.Theairvolumeattheattenuatorisoptimizedtodampenpulsationwhich
isharmfulforpapermakingprocess.Themeasuringsensoroftheoverflowsurface
levelisincludedinthedelivery.
Theattenuatingtankontheheadboxisdesignedsothatitcanbepluggedtoallowthe
headboxutilizeinfuturegapformer.

 TURBULENCEGENERATOR
Togenerateasuitablemicroturbulence,aturbulencegeneratorofstainlesssteelis
placedbetweentheequalizingchamberandslicesection.Itiscomposedofaperforated
plateandatubebankattachedtoit.Onbothsidesoftheturbulencegenerator,thereare
channelsforfeedingadditionalstock.Theflowinthesechannelsiscontrolledbyan
adjustableremotecontrolvalve.Theedgeflowchannelsareequippedwithmagnetic
flowmeters.
SLICESECTION
Theapronisaboxbeamfixedwithscrews.Thebottomsurfaceoftheaproniskept
cleanbyawatershower.Theshowerpipeisincludedinthedelivery.
Thetopsliceisaboxbeamadjustablebyelectromechanicmechanisms.Bothendsare
equippedwithaconnectionforpressuremeasurement.Apressuretransmitteratthe
backsideisincludedinthedelivery.Thefrontsideconnectionisprovidedforthe
customer'spressuretransmitter.Bothendsoftheslicesectionarefittedwithdoorsthat
canbeopenedforcleaning.

 

 

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