Capt. A.K. Sharma- Ta Tankers nkers - COW -
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What is Crude Oil Washing? • The process of washing the tanks of a crude oil tanker with crude oil rather than with water as used to be done in earlier days.
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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Let us now look at how this is achieved! Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW (COW) - WHY? •Increasingly restrictive legislation •Need to stop oil pollution completely •Oil industry stepped up its search or improved methods o cleaning tan!s" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW (COW) •#a$ority o oil tan!ers carry crude oil •Crude carriers - %iggest pollution threat" •International &greement &greement re'uired to stop all oil tan!ers carrying salt-ater %allast in cargo tan!s" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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Implicatins! ar reaching ery much higher transportation costs a)*rom reduced carrying capacity o individual oil tan!ers itted ith more segregated %allast tan!s" %)+,tensive modiication re'uired to %)+,tensive e,isting ships"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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Alternati#e cleanin$! • o o%tain Internatio International nal &greemen &greementt on such a controversial matter not easy • Idea as seriously considered %y I"#"O" • +arly ./012s oil companies commenced investigating investigati ng other alternatives" • Water -not a good cleaning agent or crude oil • & Solvent as re'uired" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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&'periments - (aptha cleanin$ • 3nder controlled conditions a series o e,periments ere conducted in &ru%a4 in the Netherland &ntillies" • &ter discharging discharging a cargo o crude crude oil4 the tan!s ere ashed ith Naphtha supplied rom shore4 %ut using the ship2s tan! cleaning machines"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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&'periments - Atmsphere Atmsphere cntrl cntrl • &tmosphere in each each cargo tan! as as monitored careully • 5ept over-rich or a%ove upper e,plosive limit4 • +nsuring that there as little or no ris! o an e,plosion or ire caused %y static or other actors"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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&'periments -res+lts • ery successul - clear indication that Naphtha as a much %etter cleaning agent than ater" • 6ro%lem - Naphtha is e,pensive4 not readily availa%le or cleaning tan!s on crude ships"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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,+rther &'periments • ried machine ashing tan!s ith actual cargo4 during discharge" • Not easy to persuade terminal and port authorities to permit the tan!s to %e ashed ith crude as the cargo as %eing discharged"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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,+rther &'periments • +vidence had to %e provided that the conditions governing such practices ere sae and the %eneits ere orthhile" • 7ue to careully monitored and controlled e,periments - current method o tan! ashing ith crude oil during discharge has %een accepted %y most oil terminals 8 port authorities4 8 approved %y I"#"O" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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9imiting Conditions or COW • 7evelopment o COW - gradual" • +'uipment o various types - tested4 approved or discarded hile results evaluated" • :loly it %ecame clear that crude ashing during the discharge as a ma$or %rea!through4 and gradually procedures ere developed4 accepta%le to %oth ship and shore authorities" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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9imiting Conditions or COW suita%le e'uipment re'uired • COW largely conined to ships itted ith suita%le e'uipment4 as ollos;.":hip must have an I< system and a%ility to control 8 limit O = in cargo tan!s" (upper limit o > is airly normal") Capt. A.K. Sharma- Ta Tankers nkers - COW -
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9imiting Conditions or COW suita%le e'uipment re'uired =" *i,ed-in-place machines4 mounted through the dec! ith suita%le no@@les or crude ashing4 and i,ed piping ith pumps mounted in the cargo pump room4 and not the engine room"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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9imiting Conditions or COW suita%le e'uipment re'uired A"&larms and monitoring m onitoring ail-sae devices must %e itted to ensure that the Inert
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation • #ain o%$ective o COW - to remove crude residue rom cargo tan!s • Besidue upto . o cargo loaded" • A114111 dt tan!er A111 tons" • I COW eectively done4 BOD cut to around E11 tons4 (most entrapped in pipeline system and slop tan!s)" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation • &t present COW not a complete su%stitute or ater ashing • 7oes not dispense ith 9"O"" i ater %allast is carried in crude tan!s or pumped through cargo piping"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation • 9arge crude tan!ers itted ith I<: 8 closed loading 8 discharging systems need to have an individual chec! list to ensure all saety and monitoring e'uipment as ell as the actual pumping and cleaning e'uipment is or!ing eiciently and ree rom lea!s"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation • *ailure o any e'uipment may $ustiy shutting don COW or saety or other operational reasons" • Numerous types o e'uipment 8 methods m ethods used to crude-ash individual ships" • aries considera%ly - ship 8 circumstances" • O"C"I"#"*" O"C"I"#"*" - hand%oo! hand% oo! called ca lled 2
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COW Operation • #ost popular method at the present time appears to divide COW o individual tan!s into to distinct phases" ." op ash (sometimes divided into to separate operations) =" Dottom Wash"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation Top Wash • Commences hen tan! still one third ull" • 7ec! mounted machines turned on and e,posed areas o tan! ashed ith $ets o crude - pressure o .1-.= !gFcm = 4 according to the type and num%er o machines used" • +,posed areas let ith a thin ilm o crude4 Capt. A.K. Sharma- Ta Tankers nkers - COW -
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Full Cargo Tank discharge has coenced
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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W"#$ T"# T%$& '( %)O*T "%LF #+,T- ,O/%++# +%C"'$#( FO+ 012O TO 32O
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation Top Wash • Clingage drops to tan! %ottom and is discharged ith the cargo ashore" • Normally a cargo pump is used to provide crude oil to the tan!-ashing machines" • an! ashing machines have an individual capacity o .E1 to .0E cu%ic metres per hour" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation Bottom Wash • When oil in the tan! is airly lo4 %ottom ashing commences" • In some cases this involves using machines itted on mounts or platorms near the %ottom" • hese machines are normally su%merged hen cargo is in the tan!4
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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W"#$ T"# T%$& '( %L+O(T #+,T- 4056+7 ,O/%++# +%C"'$#( FO+ 32O TO 82O
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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W"#$ T"# T%$& '( #+,T,O/%++# +%C"'$#( FO+ 82O T TO O 2O
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation Bottom Wash • Dottom mounted machines are very useul4 not only to ash sludge o the tan! %ottoms4 %ut to reach areas o the tan! screened %y some structural mem%ers and rame rom %eing eectively cleaned %y the through-dec! mounted machines"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW Operation Bottom Wash • Dottom ashing depends largely on the %ottom %eing !ept uncovered so that the crude $ets can move the sludge" • :tripping must %e e eective ective 84 i possi%le4 should %e conducted %y use o one or more eductors driven %y a cargo pump" • he eductor ould normally discharge into one or %oth o the slop tan!s" • :lop tan! level - careully monitored" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW #achines • Not all i,ed-dec! or su%mergedmounted machines are suita%le or crude ashing" • #any o the older types have unsuita%le4 no@@les and are prone to lea! at glands and other ittings hen used or crude" • arious ma!es are in use"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW #achines Lavomatic Selective Arc T/C machine.
• :uita%le or crude and ater ashing" • *i,ed through-dec! mounting" • *itted ith a single no@@le on the end o the drop-pipe and operated %y a simple gear train"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW #achines Lavomatic Selective Arc T/C machine.
• #achine 8 drop-pipe can %e ithdran or maintenance through aperture in dec! • 7rivingFtiming mechanism mounted a%ove dec!" • Can %e porta%le or an integral part o each machine" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW #achines Lavomatic Selective Arc T/C machine.
• 6orta%le version can %e hydraulically or pneumatically driven" • *i,ed drivingFtiming mechanism is hydraulically operated" • 7rivingFtiming device - angle o no@@le on each machine can %e controlled or top ashing or %ottom ashing cycles Capt. A.K. Sharma- Ta Tankers nkers - COW -
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COW #achines Lavomatic Selective Arc T/C machine.
• &rc 8 radius o action should meet the re'uirements o the particular ash cycle" • 7epending on type o e'uipment used 8 si@e o ship4 as many as .11 machines may %e re'uired4 ith .1 - .E in any one tan! to clean a A114111-d""t" tan!er" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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T"# (%+# ,OC#(( ("O*L9 )# #,#%T#9 FO #%C" (*)(# (*) (#:*# :*#$T $T T% T%$& T"%T '( C*9# O'L W%("#9 Capt. A.K. Sharma- Ta Tankers nkers - COW -
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#+#+)# #+#+) # T"% T"%T T W%(" T'+ T'+'$ '$/( /( %$9 +%C"'$# ,O/%++# %$/L#( %# TO )# %( %( ,# T"# C*9 C *9# # O' O'L L W%(" ("'$ '$/ / +%$*%L +%$*% L OF T"# ("', Capt. A.K. Sharma- Ta Tankers nkers - COW -
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#/*L%T #/*L% T'O$( #:*' #:*'# # • %LL T% T%$&( TO )# )%LL )%LL%(T#9 %(T#9 %# TO )# C*9# O'L W%("#9 F'(T • TW#$T- F';# ,#C#$T ,# C#$T OF T"# T"# )%L%$C# T%$&( %# TO )# C*9# O'L O' L W% W%(" ("#9 #9 • %LL %LL T%$&( T%$&( TO )# W%(" ("#9 #9 %T L#%(T O$C# #;#- FO* +O$T"( +O $T"( Capt. A.K. Sharma- Ta Tankers nkers - COW -
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C*9# O'L T%$ W'T" (#/#/%T#9 )%LL%(T T%$&( %$9 63 C.O.Ts.
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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+%(T# 9#C'9#( 4%( #:*'#97 TO #, 6C 1C %$9
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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T"'( L#%;#( % )%L%$C# OF 6= C.O.Ts. OF W"'C" 61> %# %# TO )# C.O.Wed. C.O.Wed. i.e. T% T%$&(
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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$#@T ;O-%/# T"# "#%;- W#%T"# )%LL%(T T%$&( ,L*( %$OT"# 61> OF T"# C.O.Ts. %# TO )# 9O$#
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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% F*T"# 61> OF C.O.Ts ,L*( T"# "#%;W#%T"# )%LL%(T T%$&( W'LL )# C.O.Wed T"# FOLLOW'$/ ;O-%/#
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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T"# L%(T 61> OF C.O.Ts ,L*( T"# "#%; "#%;W#%T"# )%LL%(T T%$&( W'LL )# C.O.Wed '$ T"# FO*T" ;O-%/#
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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CO$9'T'O$( CO$9'T' O$( '$FL*#$ '$FL*#$C'$/ C'$/ COW #(*LT • +%C"'$# $*+)# LOC%T'O$ $OAAL# 9'%+#T# • W%("'$/ ,#((* ,#((*# # • *LL%/# W"#$ W%("'$/ (T%T#9 • W%("'$ ("'$/ / T'+# T'+# • +%C"'$# ,O/%++'$/ • (T',,'$/ #FF'C'#$C• 9%'$ "OL# LOC%T'O$ $*+)# ('A# • T'+ OF T"# ("', • C*9# O'L (,#C'F'C%T'O$( (,#C'F'C%T'O$( Capt. A.K. Sharma- Ta Tankers nkers - COW -
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Capt. A.K. Sharma- Ta Tankers nkers - COW -
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&dvantages &dvanta ges o COW ." &s the tan!s are ashed ith cargo during dischargea) he crude oil residue let clinging to the shipGs side and internal mem%ers is reduced su%stantia su%stantially lly"" %) he %uild up o sludge and as in the tan! %ottoms is largely eliminated"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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&dvantages &dvant ages o COW COW ="+,perience has shon that cargo loss during tan!er transportation is reduced as a result o a comparison %eteen ships using COW and others cleaning conventional means" In other ords4 %y ashing ith crude oil during discharge4 more o the cargo discharged ashore and the individual tan!s are let a lot cleaner" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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&dvantages &dvantag es o COW A"an!s4 hich have %een ashed ith crude oil4 re'uire ar less cleaning and ater ashing4 either or clean %allast or or entry into a repair yard"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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&dvantages &dvanta ges o COW "9ess dirty %allast and ash ater are re'uired or COW4 so the potential or pollution is reduced during tan! cleaning at sea"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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&dvantages &dvanta ges o COW E"With less salt ater ashing4 steel corrosion ithin the cargo tan!s is reduced
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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7isadvantages o COW here are three main disadvantages to COW as practiced at the present time." It does not entirely eliminate the need or ashing ith salt ater4 either or clean %allast or entering a repair yard" It also does nothing to clear and gas ree pipelines ithin the ship"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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7isadvantages o COW ="he need or ships to %e itted ith an inert gas system and i,ed ashing machines designed or crude ashing4 means that a lot o older and smaller ships are una%le to avail themselves or COW ithout ma$or modiication and e,penditure"
Capt. A.K. Sharma- Ta Tankers nkers - COW -
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7isadvantages o COW 3" COW -hen ship is discharging • #eans that normal discharge prolonged
• Whole ship COW - normal shore acilities discharge time upto =E o normal" • I COW rotational (CD J selected tan!s) this igure can %e reduced to appro," .1-.E o the normal discharge time4 • O%viously crude recovered ill %e less" Capt. A.K. Sharma- Ta Tankers nkers - COW -
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%9;%$T%/#( OF C.O.W. "'/"# C%/O O*T O*T55T*$ 9*# 9* # TOB
• L#(( CL'$/%/# L#(( (L*9/# 9#,O('T( #FF'C'#$T 9%'$%/# ;LCC #(T'+%T #(T'+%T#9 #9 .O.). %FT# 9'(C"%/#
•W'T"O*T COW 5 0222 +8 •W'T" COW
5 822 +8
)#$#F'T( #F'$##F'$#- ("',OW$# C"%T## Capt. A.K. Sharma- Ta Tankers nkers - COW -
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%9;%$T%/#( OF C.O.W. ,OLL*T'O$ %;O'9%$C# 9*# TOB
• L#((# O'L '$ 9#, 9#,% %T T*# *# )%LL%(T • L#((# W%T# W%("'$/ #$O*T# • $O W%T# W%(" FO (L*9/# CO$TOL • L#((# L#((# (LO, #CO;##CO; #- %T #$9 OF )%LL%(T ,%((%/# • )#$#F'T( #$;'O$+#$T OW$# #F'$#Capt. A.K. Sharma- Ta Tankers nkers - COW -
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%9;%$T%/#( OF C.O.W. L#((# (%LT CO$T%+'$%T'O$ 9*# TOBB TO
• #9*C#9 W%T# W%("'$/ T"##FO# L#((# (%L (%LT T '$TO9*CT'O$ '$TO9*C T'O$ '$TO T"# T% T%$&( )#$#F'T( C%/O #C#';#( #F'$#Capt. A.K. Sharma- Ta Tankers nkers - COW -
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%9;%$T%/#( OF C.O.W. • C%/O C%-'$/ C%,%C'T'$C#%(#9 "#$C# "'/"# F#'/"T #%$'$/( • )#TT# COO('O$ CO$TOL • #9*C#9 WO&LO%9 O$ )%LL%(T ,%((%/# • 9%(T'C #9*CT'O$ '$ 9-9OC& ,#,% ,# ,%%T %T'O$ 'O$ T'+# Capt. A.K. Sharma- Ta Tankers nkers - COW -
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? Only advantages Capt. A.K. Sharma- Ta Tankers nkers - COW -
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9'( 5 %9;%$T%/#( OF C.O.W. '$C#%(# '$ • 9'(C"%/# ,#'O9 • ,OT WO& LO%9 LO%9 • ,OLL*T'O$ '(&( • /%( /#$#%T'O$ • ,#((*# (*/# '(&( • (&'LL#9 +%'$T. #:*'#+#$T • #:*',+#$T CO(T( Capt. A.K. Sharma- Ta Tankers nkers - COW -
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