Table of Contents 1.0 Introduction............. Introduction................................. ........................................ ....................................... ....................................... .................................. ................ 4 2.0 Process Process Description....... Description........................... ........................................ ....................................... ........................................... ............................ .... 4 2.1 Assumptions................... Assumptions....................................... ........................................ ....................................... ....................................... ......................... ..... 5 2.2 Process Design and Methodology.............................................. Methodology.......................................................................5 .........................5 3.0 Operational Design........................... Design............................................... ........................................ ........................................ ........................... ....... 13 3.1 ontrol !ystem Design............................... Design.................................................. ....................................... ................................... ............... 13 3.2 Operating Procedures...... Procedures.......................... ........................................ ........................................ ......................................... .....................1" 1" 3.3 #A$ID !%&D' !%&D' (!)% #*A% *+#A,-*/............. *+#A,-*/................................. .................................................. .............................. 1 4.0 Mechanical *ngineering *ngineering Design........................... Design............................................... ....................................... ........................... ........20 20 4.1 Mechanical Draing.......................... Draing.............................................. ........................................ .................................... .......................... .......... 25 Part Part .................................. ...................................................... ........................................ ........................................ ....................................... ........................... ........ 2 1.0 Introduction (Flash Vessel) ...........................................................................................2
1.1 !cope o or................................ or.................................................... ........................................ ........................................ ........................... ....... 2 2.0 Process Process Design........................... Design............................................... ........................................ .................................................. ................................. ... 2 2.1 Design methodology.................................. methodology...................................................... ............................................. ..................................... ............ 2 2.2 asic Design Data.............................................. Data.................................................................. ...................................... ............................. ........... 2 2.3 Process design design calculation................................ calculation...................................................................... .................................................. ............ 2 3.0 Operational Design........................... Design............................................... ........................................ ........................................ ........................... ....... 30 3.2
Operating procedure.................... procedure....................................... ....................................... .............................................. ..........................31 31
Operational check out list procedure [6] .........................................................................31
3.3 !aety !tudy (#A$ID/....................................... (#A$ID/........................................................... .................................... .............................. ................ 34 4.0 Mechanical design.............................. design.................................................. ........................................ ............................................. ......................... 3 4.1 Mechanical Draing.................................... Draing........................................................ ..................................................... ................................. 45 5.0
ritical e6ie................ e6ie.................................... ........................................ ....................................................... ......................................... ...... 4"
7lash %an................................... an....................................................... ........................................ ...................................... ................................ ................. ... 4" #eat *8changer..................... *8changer........................................ ....................................... ........................................ .......................................... ...................... 4" eerences.. eerences...................... ........................................ ........................................ ............................................................ .................................................. .......... 4
9ist o 7igure Figure 1 P&I diagra! "or shell and tu#e heat e$changer .........................................................15
7igure 2 %orrispherical orrispherical head :10;..................................... :10;......................................................... .................................... ...................... ...... 21 7igure 3 Mechanical design o heat e8changer........................................ e8changer..........................................................25 ..................25 Figure % Piping and Instru!entation diagra! "or "lash tank ........................................................30 Figure 'tresses in a c lindrical lindrical shell under co!#ined loading [] ..............................................3< Figure 6 Principal stresses stresses on up*+ind side [] [] ......................................................................41 Figure , -pical -pical straight skirt support design [] ....................................................................43 7igure Flange ring di!ensions [] ..................................................................................44 Figure 'tandard #olt si/e % and di!ensions [] ................................................................44 Figure 10 Flash tank !echanical design ................................................................................45
9ist o %a=le -a#le -a#le 1 'trea! ta#le "or the inlet and out strea! o" process "luid in 23*10 .....................................3 -a#le Iteration su!!ar o" condensing coe""icient .................................................................. -a#le -a#le 4 Iteration process "or con5erging o5erall heat trans"er coe""icient .......................................10 ......................................................... ........................................ .......................................... ......................12 12 -a#le % esign Outco!e ..................................... -a#le -a#le o!ponent o" control sste! and its "unction in heat e$changer P&I ("igure 1) ..................13 -a#le -a#le 6 'lurr spill accident respond ...................................................................................1"
%a=le %a=le !)% #eat #eat e8changer e8changer ha>id study...................... study.............................................................. ............................................ .... 1 -a#le 7 'tandard skirt di!ension ........................................................................................24 -a#le -a#le 2eat e$changer speci"ication sheet .........................................................................25
9ist o 7igure Figure 1 P&I diagra! "or shell and tu#e heat e$changer .........................................................15
7igure 2 %orrispherical orrispherical head :10;..................................... :10;......................................................... .................................... ...................... ...... 21 7igure 3 Mechanical design o heat e8changer........................................ e8changer..........................................................25 ..................25 Figure % Piping and Instru!entation diagra! "or "lash tank ........................................................30 Figure 'tresses in a c lindrical lindrical shell under co!#ined loading [] ..............................................3< Figure 6 Principal stresses stresses on up*+ind side [] [] ......................................................................41 Figure , -pical -pical straight skirt support design [] ....................................................................43 7igure Flange ring di!ensions [] ..................................................................................44 Figure 'tandard #olt si/e % and di!ensions [] ................................................................44 Figure 10 Flash tank !echanical design ................................................................................45
9ist o %a=le -a#le -a#le 1 'trea! ta#le "or the inlet and out strea! o" process "luid in 23*10 .....................................3 -a#le Iteration su!!ar o" condensing coe""icient .................................................................. -a#le -a#le 4 Iteration process "or con5erging o5erall heat trans"er coe""icient .......................................10 ......................................................... ........................................ .......................................... ......................12 12 -a#le % esign Outco!e ..................................... -a#le -a#le o!ponent o" control sste! and its "unction in heat e$changer P&I ("igure 1) ..................13 -a#le -a#le 6 'lurr spill accident respond ...................................................................................1"
%a=le %a=le !)% #eat #eat e8changer e8changer ha>id study...................... study.............................................................. ............................................ .... 1 -a#le 7 'tandard skirt di!ension ........................................................................................24 -a#le -a#le 2eat e$changer speci"ication sheet .........................................................................25
1.0 Introduction 2eat e$changer is selected as part o" the !a8or design +ith the purpose o" heating up the spent li9uor reccled "ro! the precipitation process do+nstrea! in the alu!ina re"iner plant. -he acti5e caustic soda content o" the spent li9uor: +hich intended to #e reccled into digester "or #au$ite digestion: !ust #e raised to a te!perature higher than that re9uired in #au$ite digestion so as to pre5ent the interruption o" phsical and che!ical conditions o" the attack !ediu!. -his is !ainl #ecause usual #au$ite te!perature #eing "ed into digester digester is insu""icient and the the te!perature o" the attack li9uor li9uor !ust #e raised "ro! 10 o to a#out 16 o in order to o#tain a te!perature o" 1% o in the li9uor "or #au$ite digestion. -heoreticall: the spent li9uor reccled "ro! precipitation process +ill circulate through a series o" heaters and to #e heated up "ro! 70 o to roughl 10 o # heat e$changing +ith 5apor "ro! the "lash tank e5aporator. 2o+e5er: the !ain "ocus o" the design is to achie5e the outlet te!perature o" 110.7 o as si!ulated in ';'< at the last heater +hich "eed +ith 5apor "ro! "irst "lash tank in the alu!ina re"iner plant [%]. -he process para!eter to achie5e the design re9uire!ent is pro5ided #elo+ +here the data is e$tracted "ro! ';'<. -a#le -a#le 1 'trea! ta#le " or the inlet and out strea! o" process "luid in 23*10 Para!eter '01 '0%1 '0%0 Vapor "raction 1.00 0.00 0.00 =i9uid "raction 0.00 1.00 1.00 ass "lo+rate 1.1, 1.1, 10%.% (kg>s) Pressure (kPa) 6.% 6.% 101. o -e!perature ( ) 17.6 1.16 10.6 2eat dut ( k?>h) 6.,@7 ,.@7 .,,@10 Po+er (kA) *1,%7.0, *00,.70 *10%0%.0
'0% 0.00 1.00 10%.% 101. 110.7 1.@ *10%%6.0
1.1 Objective of the design •
-o design an e""ecti5e heat e$changer +ith the deter!ination "or heat trans"er area re9uired "ro!
•
the gi5en heat dut and te!perature di""erence #et+een hot and cold strea!. eter!ination o" pressure drop at the tu#e side o" the heat e$changer and to achie5e the shell side
•
pressure drop as in ';'< ';'< !odel. Aork out operational design +hich co!prises o" i!ple!entation o" control sste!: operation
•
procedures and as +ell +ell as 2
2.0 Process Descripti Description on -he heat e$changer +ill use energ "ro! 5apor hot strea! discharged "ro! "lash tank to heat up the process cold strea!. -he hot inlet strea! o" the heat e$changer is purel 5apor phase +ith !ass "lo+ rate and te!perature o" 1.1,kg>s and 17.6 o and e$it at te!perature o" 1.16 o. For the cold strea!: spent spent li9uor enter the heater at a "lo+ rate o" 10%.% kg>s and te!perature te!perature o" 10.6 o and e$it at te!perature 110.7 o and 0.o.
Fro! the data pro5ided a#o5e: the onl data that is not relia#le is pressure "or the process cold strea! ('0%0 & '0%). -he ';'< !odel calculated it as at!ospheric pressure as in stead state ';'< !odel: it does not take into consideration o" pressure drop calculation neither in pipeline nor in shell side or tu#e side heat e$changer pressure drop. 2o+e5er: the inlet pressure "or 5apor strea! is dependa#le as ';'< a#le to calculate the "lash tank pressure through V=@ e9uili#riu! calculation. It is also the pressure +hich target target to achie5e at the shell shell side o" heat e$changer. e$changer.
2.1 Assumptions 1.
2.2 Process Design and Methodology In the heat e$changer design: CernDs !ethod is selected due to its si!ple calculation !ethod in pro5iding satis satis"ac "actor tor heat heat trans trans"er "er coe"" coe""ici icient ent "or stand standard ard design design.. -he !ethod !ethod de5elo de5eloped ped +as #ased #ased on e$peri!en e$peri!ental tal data "or co!!ercial co!!ercial heat e$changers e$changers and the data o#tained o#tained +ere correlated correlated # si!ple si!ple e9uation analogous to e9uation o" "lo+ in tu#e. 2o+e5er: the dra+#ack o" the design !ethod is that it does not ade9uatel account "or #a""le to shell and tu#e to #a""le leakages and as +ell as # passing. passing. 2ence: the pressure drop esti!ated through the !ethod is less satis"actor co!pared to Eell or ela+are !ethod []. 1. Heat Heat Exch Exchang anger er Select Selection ion [2,3] [2,3]
'hell and tu#e heat e$changer is chosen !ainl due to the reason that it consists o" large heating area per unit 5olu!e and thus high heat trans"er rate in a clean condition. =o+er capital cost +ill #e resulted in co!pariso co!parison n to that #e"ore the pro5isio pro5ision n o" sparing sparing is taken into consideration consideration "or !aintenanc !aintenancee and cleaning. In addition: it is a o"" the shel" solution +ith !an suppliers and +orld reno+ned technolog. On the the other other hand: hand: in high high te!per te!peratu ature re applic applicati ation on usuall usuall +ith +ith te!per te!peratu ature re a#o5e a#o5e 1%0 o: it has the disad5antages o" high tendenc "or tu#e #lockages: high scaling issues +hich !ake the cleaning and !aintenan !aintenance ce di""icult. di""icult. 2ence: 2ence: split split ring "loating head is selected "or the purposes o" ease o" cleaning cleaning +here de"ecti5e tu#e can #e replaced or plugged easil: shell side cleaning is "a5ora#le at in"re9uent inter5al: !uch less #pass area as !ore tu#e per shell dia!eter can #e acco!!odated than the pull through "loating head #undle. oreo5er: it is !ore "le$i#le +ith large te!perature di""erential +here it is good in startup or e!ergenc condition since ther!al stress at operating le5el is lo+ (lo+
∆ T ) in the
process design. design.
'eries 'eries o" "actor "actorss like like corro corrosio sion: n: "oulin "ouling g and cleani cleaning ng consid considera eratio tions ns ha5e ha5e #een #een accoun accounted ted.. 2ighl 2ighl corrosi5e spent li9uor !ainl due to its acti5e content o" caustic soda is assigned to #e placed in the tu#es +here the corroded tu#es can #e replaced easil. oreo5er: cost also can #e sa5ed on !aterial construction on the shell side +here the #od o" the shell needs not to #e !ade o" corrosi5e*resistance !aterial.
s so that to reduce scaling and o#tain reasona#le !aintenance "re9uenc. -here"ore: spent li9uor is to #e allocated in the tu#e side o" heat e$changer. On the other hand: shell side condensation o" 5apor is pre"era#le due to the reasons reasons stated #e"ore. "etailed "esign #alclation
In the design: hori/ontal #a""led shell and tu#e condenser is e!ploed as the design is good "or single co!ponent 5apor: relati5el high and lo+ pressure drop design: and li9uid coolant. It is to note that in actual case it is not a coolant as spent li9uor is to #e heated up. -he shell side condensation calculation "or pressure drop and heat trans"er coe""icient coe""icient calculation !ethod +ill #e "ollo+ing "ollo+ing +hat ha5e #een proposing "or calculation in a tpical condenser design +hich takes into consideration o" condensing 5apor outside the the tu#e tu#e +hile +hile single single phase phase "lo+ "lo+ calcul calculati ation on +ill +ill #e accoun accounted ted "or pressu pressure re drop drop and heat heat trans" trans"er er coe""icient calculation in tu#e " or spent li9uor. 3. Heat Heat dt$ dt$ %heat %heat tran transfe sferr rate rate&& [3] [3]
9
m ´
∆ H
1.1, (,7.7, G %.,%) 7.0 kA '. Overa Overall ll heat heat trans transfer fer coeffi coefficie cient nt [3] [3] O5erall heat trans"er coe""icient is the reciprocal o" the o5erall resistance to heat trans"er and as the "irst trial it is deter!ined to #e as 000 A>! o. 2<-2 2<-2 pro5ided the 5alue o" o5erall heat trans"er coe""icient o to #e 100A>! in partiall scaled condition and high heat trans"er coe""icient is "a5ora#le as it is proportional to heat trans"er rate. -hus: it is assu!ed that in clean tu#e conditionH the o(ass) is 000A>!o. (. )ean )ean te*+ te*+era eratr tree diff differe erence nce [3]
R=
( T −T ) 138.26 −129.16 = =1.21 ( t −t ) 110.8−( 103.26 ) 1
2
2
1
S=
( t −t ) 110.8−( 103.26 ) = =0.22 ( ) T − t − 138.26 103.26 ( ) 2
1
1
1
[
( 1− )
S √ ( R +1 ) ln ( 1 − RS ) 2
F t =
( R−1 ) ln
[
]
[ R +1 −√ ( R +1 ) ] 2− S [ R + 1 + √ ( R + 1 ) ]
2 − S
2
2
]
1.21 × 0.22 1−(¿)
( 1−0.22 ) (¿ ] ¿ ¿ √ ( 1.21 + 1 ) ln ¿ F t =¿ 2
-hen the logarith!ic !ean te!perature can #e calculated4
T T T
(¿ ¿ 1−t ) (¿ ¿ 2−t ) ln ¿ (¿ ¿ 1−t )−(T −t ) ¿ ∆ T lm =¿ 2 1
2
∆ T lm =
2
1
( 138.26 −110.8 )−(129.16 −103.26 ) =26.67 ℃ ( 138.26 −110.8) ln (129.16−103.26 )
E "irst guessing t+o tu#e passes "or a hori/ontal heat e$changer: condensation in one shellH true te!perature di""erence can then #e deter!ined through the 5alue calculated a#o5e4
∆ T m= F t ∆ T lm ∆ T m=0.70 × 26.67=18.66 ℃
. Heat transfer area [3] -he trial heat trans"er area is calculated as "ollo+s4 3
q 28923.03 × 10 A o = = =775.04 m2 U o,ass ∆T m 2000 × 18.66 -. Selection of tbe di*ension [3] -he tu#e di!ension is selected #ased on tu#e cleaning practices as !ini!u! li!it o" the outer dia!eter is appro$i!atel 0!!. E taking the tu#e di!ension as . !! outer dia!eter +ith 1.,6 !! inner dia!eter as reco!!ended # hand#ook the sur"ace area o" one tu#e is calculated as #elo+ []4
π $ =
. $ .1% $ ,. 0.1 ! -he tu#e length ,.! is selected #ased on the criteria that high cost can #e a5oided +ith long tu#e used. oreo5er: the tu#e length is chosen +ith the consideration that length to shell dia!eter ratio !ust #e in the range o" to 10 "or #est per"or!ance. . /*ber of tbes [3] Ju!#er o" tu#es is co!puted through the "or!ula o"
A o J
0.
775.04
A s
0.51
116.
be a$ot [3]
-riangular pitch is chosen as the con"iguration is co!pact and pro5ides higher heat trans"er. -he "or!ula "or tu#e pitch is as "ollo+s4 Pt 1.do 1.$ . ,.,7 Aith calculated nu!#er o" tu#es and selected tu#e O: shell #undle dia!eter can easil #e "ound through e9uation o": http4>>+++.hcheattrans"er.co!>shellKandKtu#e.ht!l
( )
N t Db= d o K 1
1
n1
22.225
(
)
1516.23 0.249
1 2.207
=1152.50 mm
Ahere the constant C 1 and J1 are deter!ined "ro! ta#le 1.% in []: +ith the con"iguration o" tu#e passes and triangular pitch selected. Ju!#er o" tu#e in centre ro+ +hich is also the ro+ at the shell e9uator is calculated #4
D b Jr
1152.50
Pt
27.78
%1.%7
1. Shell4Side #oefficient [3]
!o at the shell side: the e9uations "or !ean te!perature and +all te!perature are gi5en #4 ean te!perature
T
(¿ ¿ 1 + T )
138.26−129.16
¿ ¿
2
'hell side
2
¿ t
(¿ ¿ 1 + t )
(110.8 +103.26 )
2
-u#e side
2
1.,1
2
10,.0
2
¿ -u#e Aall -e!perature (-' G -+) $
∅
(-' G --) $ o
(1.,1 G -+) $ 100 (1.,1 G 10,.0) $ 000 -+ 7.1% o 133.71 + 98.14
ean -e!perature ondensate
2
11. o
Phsical properties at 11. o "or condensate
μ L
0.000%1 Js>!
ρ L
%6.%7 kg>!
Vapor densit at !ean 5apor te!perature
ρv =
PM 2.64 18.016 = RT 8.314 !−2 ( 133.71 + 273 ) 1.% kg>!
k L
0.67 A>!C
" # =
$ % lnt
13.17
7.32 1516.23
0.001 kg>s!
2
<5erage nu!#er o" tu#e in 5ertical tu#e ro+: tpicall
2
Jr5
3
3
o" the nu!#er in the central ro+ is used4
2
$ Jr
3
$ %1.%7 ,.6
11. )ean coefficient for a tbe bndle [3]
-he e9uation #elo+ accounts "or condensation o" 5apor on the outer hori/ontal tu#e and as +ell as "lo+ o" condensate "ro! ro+ to ro+ o5er the Jr tu#es in a 5ertical ro+. oreo5er: it also taking into consideration o" the o#stacle "lo+ o" condensate around the tu#e as condensate is i!possi#le to "lo+ s!oothl "ro! ro+ to ro+ o" tu#es in realit.
ρ L ( ρ L − ρv ) & (hc) # 0.k = (
μ L " #
(
−1/ 6
)1> N 'v
)
946.48 946.48−1.425 9.81
0. $ 0.67 (
0.000241 0.0012
)1> $ ,.6*1>6
116,,.%,A>! o -he calculated condensing coe""icient 116,,.%, A>! o is "ar apart "ro! the assu!ed 5alue o" 100 A>!o: hence correction to - + is needed and iteration is re9uired to #e carried out. -a#le pro5ided the su!!ar o" iteration and con5erged 5alue o" condensing coe""icient. -a#le Iteration su!!ar o" condensing coe""icient 5ara*eters 6ase case 1st 7teration 'hell side !ean 1.,1 1.,1 te!perature ( o) -u#e side !ean 10,.0 10,.0 o te!perature ( ) -u#e +all 7.1% 1.1% o te!perature: -+ ( ) ondensate !ean 11. 11.% o te!perature ( ) ean condensing 100.00 10. coe""icient "or tu#e #undle: (hc) # (A>!o)
2st 7teration 1.,1
10,.0 1.7 11.0 10. (con5erged)
12. be side coefficient [3]
πD -u#e cross sectional area: - '<
4
π
4
2
N ¿ o( )ass*s
$
1516.23
2
( 19.736 )
$
2
0. !
ensit o" spent li9uor at 10,.0 o 1%,.7 kg>!
-u#e 5elocit
ρ (¿¿ SL)( T +SA ) m´SL
¿
1049.54
1247.28 0.23
.6 !>s Prandtle nu!#er +hich de"ine ratio o" !o!entu! di""usi5it to ther!al di""usi5it and Le nolds nu!#ers that deter!ine tpe o" "luids "lo+ inside the tu#es are gi5en #4
+ ) μ Pr
k
3.66 !
vρ d , Le
μ
3
0.00049
0.1898
.%
3.63 1247.28 1 9.736 !
0.00049
−3
17%7.%0
0.7
k ( 0.8 0.33 d ℜ P' ( 1+ ) hi 0.0 d L
0.1898
0.0 1 9.736 !−3
182248.4
0.8
0.33
9.45
(1 +
19.736 ! 7.34
−3
0.7
)
,16.06 +>! o 13. Overall Heat ransfer #oefficient [3] Jickel allo %00 is selected as the tu#e !aterial and +ith a conducti5it o": k+ o" %. % A>!N and "ouling coe""icient o" stea! condensate and a9ueous salt solution are assu!ed to #e 000A>! o respecti5el 0 +hich is at the !a$i!u! o" the range o" "ouling "actor coe""icient 000A>! o respecti5el so as to !a$i!i/e the oH the o5erall heat trans"er coe""icient is calculated # the e9uation o" 1
U o
=
1
ho
+
1
hod
22.225 ln 1
U o
=
1 1205592
+
1 5000
+
d o ln
(
+
d i
k w
22.225 19.736
2 × 24.54
U o= 1404.92
d o
)+
+
d o d 1
22.225 19.736
×
×
1
hid
+
1 5000
d o d i
+
×
1
hi
22.225
1
19.736
7516.06
×
$ 2
m -℃
-he o5erall heat trans"er coe""icient is calculated as
1404.92
A>!N +hich is "ar "ro! the esti!ated
o o" 000 A>! N. Iterations ha5e to #e conducted to get the con5erged o 5alue. -a#le #elo+ pro5ided the su!!ar o" iterated data +ith the use o" 1%0%. A>! o as the trial coe""icient "or repeated steps calculations. -a#le 4 Iteration process "or con5erging o5erall heat trans"er coe""icient 5ara*eters 6ase #ase 1st 7teration o(ass) 000 1%0%.
2st 7teration 16., 111.70 1., 1., 16,,.,6 666.16 16.,
1'. Shell side +ressre dro+ [3]
heat trans"er rate and achie5e reasona#le high pressure drop across the shell o" the heat e$changer as re9uired # ';'<.
A s =
( ) t − d o ) D s l . )t
(27.78− 22.225) × 1435.07 × 602.73 ¿ ¿ A s=¿ /s
-he shell side !ass 5elocit
/s= /s=
$ s A s 13.17 0.17
=76.13 k&
2
sm
d*
-he e9ui5alent dia!eter
d *= d *=
can #e calculated as "ollo+s4
1.27
do
( P
1.27
2
t
−0.917 d o
2
is co!puted # using the e9uation "or triangle pitch arrange!ent4
)
(27.78 − 0.917 × 22.225 )=15.78 mm 2
2
22.225
Aith 5apour 5iscosit o" 0.00001 Js>! at !ean 5apor te!perature (1.,1 o): the shell side LenoldDs nu!#er can then #e calculated4
ℜ=
/sd* μ
( 76.13 × 15.78 !− ) 3
ℜ=
0.0000135
=88992.67
Fro! the Figure 1.0 in [] +ith LenoldsDs nu!#er o" 8.9 × 10 to #e 0.0: then the linear 5elocit can #e deter!ined #4
4
: the "riction "actor:
0 (
is o#tain
1s =
/s ρ v 76.13
1s =
1.43
=53.24 m/ s
-he shell side pressure drop:
∆ Ps
is deter!ined # and 5iscosit "actor is neglected4
( )( ) ( ) 2
D s L ρ v 1 s μ ∆ Ps =8 0 ( d * l. μ 2 2
∆ Ps =8 ( 0.029 )
(
525.35 19.75
)(
−0.14
7.34 602.73 1000
()
1.43 × 53.24 2
2
)=
518.93 kPa
∆ Ps =518.93 × 0.5= 259.46 kPa
1(. be side +ressre dro+ [3]
-he 5iscosit o" caustic soda at
107.3 ℃
is
0.00049 k& / ms
: and the LenoldDs nu!#er can #e
calculated4
ρ 1t d,
ℜ= ℜ=
μ 1247.28 × 1.8 × 19.736 0.00049
Friction "actor:
0 (
=128434.32
is o#tain to #e 0.007 "ro! ta#le 1.% ('innott 00). E neglecting 5iscosit
correction: the tu#e side pressure drop can #e calculated as4
[ ( )( ) ]
L μ ∆ Pt = N ) 8 0 ( d , μ 2 ∆ Pt =2
[(
8 0.0028 )
(
−m
+ 2.5
7.34 19.736
2
ρ 1 t 2
)+ ] 2.5
2
1247.28 × 1.8 2
=43.61 kPa
-a#le % "esign Otco*e Overall H8412 design s**ar$
-u#e outer dia!eter: !! -u#e inner dia!eter: !! -u#e length: ! -u#e 5elocit !>s 'hell 5elocit !>s -riangular pitch: ! 'hell ia!eter: !! Ea""le spacing: !! Ea""le cut: O5erall 2eat -rans"er oe""icient: : A>! C Pressure drop in tu#e: kPa Pressure drop in shell: kPa
. 1., ,.% .6 6.66 ,.,7 1%.0, 60., % 1,0.6 %.61 .%6
o!!ent4 -he o5erall design is satis"actor. -his is #ecause o" reasona#le tu#e side 5elocit +hich "alls in the range o" 1*!>s. 'hell side a5erage 5apor 5elocit is 6.66!>s: +hich is reasona#le as the shell side 5apor 5elocit "all in the range o" 10 *0 !>s. -he 6.6!>s is actuall taking the !ean 5elocit at inlet 5apor strea! +hich is 6.%!>s and 5elocit at outlet condensate strea! 0.07!>s -he pressure drop in shell is nearest to the 5alue o" 6.%kPa as sho+n in ';'<. -he o#tained shell side pressure is particularl designed to #e lo+er than the pressure stated in ';'< to ensure the 5apor "lo+ "ro! high pressure "lash tank to lo+ pressure +ithout re5erse "lo+. -he pressure drop in tu#e side is also !ake sense as usuall in series o" heat e$changer the 23*10 +ill ha5e the highest tu#e side pressure drop (00kPa "ro! 2<-2) and pu!p need to ensure the spent li9uid ha5e enough energ to "lo+ to+ards all the heat e$changers. -he pressure should #e o" "ro! high to lo+.
3.0 Operational Design 3.1 Control System Design ontrol sste! ha5e the ad5antages o" correcting the e""ects o" distur#ances in "eed "lo+ rate: te!perature: stea! suppl pressure and so on through 5arious tpe o" instru!entation control sste!. It can #e "eed "or+ard: "eed#ack: cascade or in"erential control. Figure 1 sho+ed the P&I diagra! "or heat e$changer that +ould #e su""icient in controlling the heat e$changer +ith the control sste! proposed. ain control o#8ecti5e is to trans"er energ "ro! hot 5apor strea! to cold spent li9uor strea!. -he tpe o" control proposed is cascade control loop. It consists o" t+o controllers in series that +orking together in order to correct the distur#ances incurred. In the diagra!: the cascade !aster te!perature indicator trans!itter (-I-) detecting 5ariation in te!perature and the sla5e controller (PI-) +ill then detects the 5aria#le that a""ect the process te!perature +hich is pressure o" the stea!. -he cascade !aster (-I) +ill then ad8ust the set point o" sla5e controller (PI) to attain the process sste! #ack to nor!al. It has the ad5antages o" accounting "or distur#ances in pri!ar 5aria#le (te!perature "or spend li9uor in the case) 9uickl and e""ecti5el. In addition: the control sste! also helps to reduce the dead ti!e and phase lag ti!e in the sste! +hich is good "or !ore e""icient control o" the process "lo+ in the heat e$changer. -he control sste! is i!portant in the sense o" too !uch or too less heat trans"er "ro! 5apor !ight lead to the target to achie5e 110.7 o at the spent li9uor outlet strea! i!possi#le.
its "unction in heat e$changer P&I ("igure 1)
Function -o pre5ent re5erse "lo+ o" 5apor -o #pass and act as a #ackup 5al5e -o isolate V*01 "or !aintenance purposes
Shell and be Heat Exchanger H8412 Components Function Vent V*16 For !aintenance purposes and to 5ent non* condensa#le air Pressure sa"et 5al5e V*6 Protection 5al5e that pre5ent the tu#e rupture due to e$tre!e pressure "luctuation rain V*6 -o drain condensate "or !aintenance purposes
:ater %#ondensate& Otlet S4'1 Components Function Isolation 5al5e V*66: V*6, -o isolate V*6 "or !aintenance purposes Qate 5al5e V*67 -o #pass and act as a #ackup 5al5e heck 5al5e V*% -o pre5ent re5erse "lo+ o" +ater
%
6
Flanged 5al5e +ith spectacle #lind V*6
-o stop> #lock the "luid "ro! "lo+ing into heat e$changer or "lo+ing out
S+ent i;or 7nlet S4' Components Isolation 5al5e V*7: V* Qate 5al5es V*%0 heck 5al5e V*% Flanged 5al5e +ith spectacle #lind V* rain 5al5e V*,
Function -o isolate V*01 "or !aintenance purposes -o #pass and act as a #ackup 5al5e -o pre5ent re5erse "lo+ o" li9uor -o stop> #lock the "luid "lo+ into heat e$changer or "lo+ing out -o drain spent li9uor "or !aintenance purposes
S+ent i;or Otlet S4'2 Components Flanged 5al5e +ith spectacle #lind V*, Qate 5al5e V*, Isolation 5al5e V*,: V*,% heck 5al5e V*6 rain 5al5e V*61
Function -o stop> #lock the "luid "ro! "lo+ing into heat e$changer or "lo+ing out -o #pass and act as a #ackup 5al5e -o isolate V*, "or !aintenance purposes -o pre5ent re5erse "lo+ o" spent li9uor -o drain spent li9uor "or !aintenance purposes
#ontrol S$ste* Components -e!perature indicator controller -I -e!perature indicator trans!itter -IPressure indicator controller PI
Pressure indicator trans!itter PI2igh pressure alar! 2 =o+ pressure alar! =
Function Lecei5e signal "ro! -I- +hich "irst co!pare the 5ariation o" set point and per"or! action on PI etect te!perature 5ariation "ro! set point and send signal to -I Per"or! action on control 5al5e to ad8ust the pressure o" 5apor etect 5ariation o" pressure "ro! set point and trans!it signal to PI -o noti" +hen pressure is high -o noti" +hen pressure is lo+
Figure 1 P&I diagra! "or shell and tu#e heat e$changer
3.2 perating Procedures #o**issioning [0]
Ee"ore co!!encing a heat e$changer into operation: it is ad5isa#le that re"erence should #e !ade to the heat e$changer speci"ication sheet: dra+ing and as +ell as na!e plate "or an special instructions. -his is to ensure the heat e$changer +ill ne5er #e operated under condition that e$ceeds those speci"ied on the speci"ication sheet "or sa"et purposes. oreo5er: local sa"et health and regulations should #e considered. Incorrect +a o" startup or shutdo+n steps +ould cause leaking o" #olted "langed 8oints and tu#e to tu#e sheet 8oint. Start + o+eration [0]
-he process "luids !ust #e introduced into the shell and tu#e heat e$changer in a +a that !ini!i/ed the di""erential ther!al e$pansion #et+een the shell and tu#es. old process strea! should "irst #e "lo+ing into heat e$changer and onl "ollo+ed # gradual introduction o" hotter !ediu! like 5apor. uring the start up: the 5ent 5al5es should #e unlock and le"t opened until all the passages ha5e #een purged o" air and co!pletel "illed +ith "luid. Shtdo
Qraduall stopping the "lo+ o" hotter !ediu! then onl "ollo+ed # colder !ediu! in the e9uip!ent. -he ai! "or gradual shut do+n is to !ini!i/ed di""erential ther!al e$pansion #et+een the shell and tu#es. <"ter co!pletel shut do+n: all co!ponents o" the e9uip!ent and as +ell as pipeline should #e drained co!pletel in order to pre5ent the "ree/ing or corrosion "ro! happening in the e9uip!ent. Aater ha!!er is un"a5ora#le in pipeline as it +ill incur !ultiphase "lo+ and it is ad5isa#le that condensate #e drained "ro! the heater during start up or shut do+n. -u#e side o" e$changer can #e #lo+n out +ith air ti reduce +ater retention in the e9uip!ent. )aintenance [0]
For dail checking procedure: it is 5ital to check "or an process "luid leaks in the sealed area o" the heat e$changer. 5eriodical *aintenance [0]
Ceep ees on corrosion or "ouling in the pipeline or heat e$changer # per"or!ing periodic cleaning to the e9uip!ent. heck "or 5isi#le cracks: "or an o" the e9uip!ents co!ponent: integrit o" liners and etc. "isasse*bl$ [0]
disconnected prior to disasse!#l. heck "or internal pressure o" the heat e$changer a"ter the hdraulic pu!p is halt "or operation and !ake sure the pressure is /ero #e"ore disasse!#ling the heat e$changer:
It is also 5ital "or users to check that the e9uip!ent is "ull depressuri/ed: 5ented: drained: neutrali/ed or drained #e"ore disasse!#le the heat e$changer. Ceep all the log #ooks that record do+n the e5ent or operation !al"unction +hich a""ect the heat e$changer per"or!ance. -his is to ensure no repeata#le !istake in operation in the "uture.
Environ*ental accident res+onse +rocedre
-he !ost corrosi5e "luid in heat e$changer is caustic soda and i!!ediate action should #e taken i" leakages are "ound.
up to 00cc
S*all
>es+onse
<#sorption or che!ical treat!ent
<#sorption Pu#lic sa"et !ust #e arge !ore than liters outside help called 1.1. eter!ine the si/e o" spill> leakage and take appropriate action according to the ta#le proposed )edi*
00 cc * liters
reat*ent )aterials austic neutrali/er or a#sorption !aterial like sand or socks <#sorption !aterials
#elo+. 1.. ontain and clean up the leaks +ith the che!ical used.
E*ergenc$ shtdo
For sa"et control: pressure relie" 5al5e and e !ergenc shutdo+n 5al5e are #eing installed into the e9uip!ent. I" pressure in the heat e$changer +ent a#nor!al: the set pressure in the pressure relie" 5al5e +ill #e acti5ated and hence relie5ing the e!ergenc situation. 2o+e5er: i" PLV !al"unction: e!ergenc shutdo+n 5al5e +ill #e acti5ated +hen it detects 0 e$tra high te!perature in the strea! and alar! +ill ring and "luid "lo+ +ill #e shut do+n i!!ediatel.
3.3 #A$ID !%&D' (!)% #*A% *+#A,-*/ %a=le !)% #eat e8changer ha>id study
3.3 #A$ID !%&D' (!)% #*A% *+#A,-*/ %a=le !)% #eat e8changer ha>id study
H!?!>" 7"
H!?!>" #!E@O>A %@B7"E:O>"&
1
Jatural isasters
H!?!>" "ES#>757O/ C H!?!>"OBS E9E/
@$tre!e heat
#O/SEDBE/#ES
Pressure #uild up in 23*10 2eat stress o" personnel
5>E9E/7O/ C "EE#7O/ C 6!>>7ES
'hut do+n operation
>7S !SSESS)E/
>E#O))E/"!7O/S
7E7HOO"
#O/SEDBE/#E SE9E>7A
>!/7/@
Possi#le
=o+
=o+
@5acuate personnel "ro! e$tre!e heat
onitor the operating te!perature o" 23*10 Install high te!perature alar! on 23*10
Pipeline an e9uip!ent ther!al e$pansion 23*10 operate higher than operating te!perature o" 70N
@$ternal @""ects
ropped o#8ects
a!age o" 23*10 Possi#le rupture o" 23*10: thus release o" corrosi5e caustic
Inspect regularl "or o5erhead e9uip!ent and possi#le loose ite!s.
nlikel
ritical
@$tre!e
Installation o" sa"et netting a#o5e 23*10
In8ur or death o" the +orkers
@$ternal @""ects
Fatigue> cracking
Lupture o" pipeline
J><
nlikel
a8or
2igh
=oss o" contain!ent racking o" 23*10 shell
%
2u!an Factors
I!proper> inade9uate training
=oss o" alu!ina production =oss o" production
J><
Possi#le
ritical
@$tre!e
ontrol 5al5e V*01 "ailure
@$plosion Jo heat e$change ("ail to open)
procedure ha5e to #e strictl o#eed
6
,
Process psets
Process psets
Flo+ de5iation
Pressure de5iation
Insu""icient te!perature to digest #au$ite ore 23*10 o5er pressuri/ed and rupture
tilities Failures
=oss o" po+er
Pressure #uild up in 23*10
Operators to o#e
the rule and regulations "ro! the operating !anual
J><
=ikel
oderate
2igh
Installation o" "lo+ control sste! at the outlet strea! o" spent li9uor
Process engineering tea! to design and electrician to install the control sste!
Possi#le
ritical
@$tre!e
Installation o" e!ergenc shutdo+n 5al5e and high te!perature alar!.
@lectrical engineering tea! to install e!ergenc shutdo+n 5al5e connected to high te!perature alar! and displa at the indicator
=ikel
a8or
@$tre!e
Visual inspection on the pipeline "or an possi#le de"ects.
Operators to per"or! the checking periodicall.
Lelie" 5al5e ascade controller sste! loop
Personal in8ur or death racking and leakage Jickel allo steel !aterials o" 23*10 and as +ell "or all the pipelines and tu#e as inlet and outlet side o" 23*10 pipelines '01: '0%0: '0%1: '0%
=oss o" "unctionalit o" cascade control sste!s
esigners> consultants to pro5ide the training.
Process engineering tea! to design and Install isolation 5al5es around !aintenance tea! 5al5e V*01 "or !aintenance o" to install #pass #roken V*01 and isolation 5al5es
Install #pass 5al5e to the control 5al5e
Fre9uent non destructi5e test "or pipeline and 5essel +all thickness
racking o" 5essel or pipeline
aintenance engineering tea! to per"or! the testing and "i$ #roken pipeline or e9uip!ent leakage.
2igh
Vent line V*16
orrosion> erosion
Operators to inspect the e9uip!ent and pipeline condition. O""shore health and sa"et e$ecuti5e to handle all the sa"et re9uire!ent rule and regulations.
a8or
psets to do+nstrea! e9uip!ent
Process psets
@lectrical engineering tea! to install alar!s
nlikel
=oss o" contain!ent
7
Operators to do te!perature !onitoring
J><
23*10 o5er pressuri/ed ("ail to close) =oss o" contain!ent ("ail to close) Increase in te!perature in 23* 10
Pro5ide ade9uate training "or operators o!pulsor in preparing operating procedure !anual # designers and the
a!age to e9uip!ent +hich !ight include 23*10
@ 9u ip !e nt >I ns tr u! ent at ion al"unction
Aearing protecti5e hard hat and as +ell as personal protecti5e e9uip!ents Per"or! non destructi5e testing (J-) on 5essel to test 5essel thickness and pipeline integrit Visual inspection o" an hairline crack on the e9uip!ent.
Process upset and a#nor!al operating condition
@nsure rigging is in good condition and operated correctl
!#7O/S
Fail open>closed 5al5es
nlikel
oderate
oderate
Eackup generator "or i!portant process e9uip!ent
aintenance engineering tea! to per"or! the testing. @lectrical engineering tea! to install #ackup generator
a!age to e9uip!ent +hich !ight include 23*10
@ 9u ip !e nt >I ns tr u! ent at ion al"unction
ontrol 5al5e V*01 "ailure
@$plosion Jo heat e$change ("ail to open)
procedure ha5e to #e strictl o#eed
J><
nlikel
a8or
2igh
Process engineering tea! to design and Install isolation 5al5es around !aintenance tea! 5al5e V*01 "or !aintenance o" to install #pass #roken V*01 and isolation 5al5es
J><
=ikel
oderate
2igh
Installation o" "lo+ control sste! at the outlet strea! o" spent li9uor
Process engineering tea! to design and electrician to install the control sste!
Possi#le
ritical
@$tre!e
Installation o" e!ergenc shutdo+n 5al5e and high te!perature alar!.
@lectrical engineering tea! to install e!ergenc shutdo+n 5al5e connected to high te!perature alar! and displa at the indicator
=ikel
a8or
@$tre!e
Visual inspection on the pipeline "or an possi#le de"ects.
Operators to per"or! the checking periodicall.
23*10 o5er pressuri/ed ("ail to close)
6
,
Process psets
Process psets
Flo+ de5iation
Pressure de5iation
=oss o" contain!ent ("ail to close) Increase in te!perature in 23* 10 Insu""icient te!perature to digest #au$ite ore 23*10 o5er pressuri/ed and rupture
Lelie" 5al5e ascade controller sste! loop
Install #pass 5al5e to the control 5al5e
=oss o" contain!ent Vent line V*16 psets to do+nstrea! e9uip!ent
7
Process psets
orrosion> erosion
Personal in8ur or death racking and leakage Jickel allo steel !aterials o" 23*10 and as +ell "or all the pipelines and tu#e as inlet and outlet side o" 23*10 pipelines '01: '0%0: '0%1: '0%
Fre9uent non destructi5e test "or pipeline and 5essel +all thickness
racking o" 5essel or pipeline
tilities Failures
=oss o" po+er
=oss o" "unctionalit o" cascade control sste!s Pressure #uild up in 23*10
=oss o" alu!ina production
the rule and regulations "ro! the operating !anual
Fail open>closed 5al5es
nlikel
oderate
oderate
Eackup generator "or i!portant process e9uip!ent
aintenance engineering tea! to per"or! the testing. @lectrical engineering tea! to install #ackup generator
=oss o" alu!ina production
4.0 Mechanical *ngineering Design -he !echanical design o" shell and tu#e heat e$changer +ill #e carried out #ased on process design data o#tained. 'hell side o" heat e$changer +ill #e designed as thin +alled pressure 5essel under the e$ertions o" internal pressure. Aith the deter!ined in"or!ation gi5en in ta#le % su!!ar o" designed !echanical co!ponents are listed as "ollo+s4 1. . . %. . 6. ,. 7. .
Pressure 5essel arrange!ent and tpe o" do!ed head and end closure. Aall thickness re9uired "or clindrical 5essel: shell co5er: channel co5ers and tu#esheet thickness ead +eight o" 5essel @lastic sta#ilit check Flanges Jo//les Qaskets 'tress calculations 'addle support
5rocess and *echanical design infor*ation
'hell and tu#e side passes4 1 shell tu#e passes -u#esD nu!#er: laout si/e and tpe4 06.%H tu#e length4 ,.%!H tu#e O4 .!!H I4 1.,6!!H e9uilateral triangular pitchH "loating tu#e sheet 'hell dia!eter and head4 'hell I4 1%.0,!!H torispherical head and car#on steel "or shell and head.
4.0 Mechanical *ngineering Design -he !echanical design o" shell and tu#e heat e$changer +ill #e carried out #ased on process design data o#tained. 'hell side o" heat e$changer +ill #e designed as thin +alled pressure 5essel under the e$ertions o" internal pressure. Aith the deter!ined in"or!ation gi5en in ta#le % su!!ar o" designed !echanical co!ponents are listed as "ollo+s4 1. . . %. . 6. ,. 7. .
Pressure 5essel arrange!ent and tpe o" do!ed head and end closure. Aall thickness re9uired "or clindrical 5essel: shell co5er: channel co5ers and tu#esheet thickness ead +eight o" 5essel @lastic sta#ilit check Flanges Jo//les Qaskets 'tress calculations 'addle support
5rocess and *echanical design infor*ation
'hell and tu#e side passes4 1 shell tu#e passes -u#esD nu!#er: laout si/e and tpe4 06.%H tu#e length4 ,.%!H tu#e O4 .!!H I4 1.,6!!H e9uilateral triangular pitchH "loating tu#e sheet 'hell dia!eter and head4 'hell I4 1%.0,!!H torispherical head and car#on steel "or shell and head. orrosion allo+ance4 !! o" corrosion allo+ance is taken "or car#on steel esign te!perature and pressure4 For sa"et design purposes: 10 e$tra o" the design 5alue +ill #e taken into account. For te!perature: the highest process "luid te!perature is selected +hile highest inlet pressure a!ong #oth the inlet strea! is chosen. esign te!perature4 1.1 $ 17.6 %,., oH pressure4 %.61 $ 1.1 %,.,kPa Per!issi#le stress4 11%.7 J>!! "or car#on steel Shell dia*eter and thicness [3]
lindrical shell is chosen as the shape "or the heat e$changer and the !ini!u! shell thickness can #e calculated "ro! the "or!ula #elo+ +hich #ased in the !a$i!u! allo+a#le stress and corrected 8oint e""icienc4
t s=
) Ds (0 −0.6 )
+%
.,1!!
-he 8oint e""icienc is taken as 0.7 +ith spot radiograph and dou#le +elded #utt 8oint. -he lo+ 8oint "actor +ill gi5e reasona#l lo+ cost and as +ell as co!pro!ise +ith thicker and hea5ier the 5essel it +ill result.
-he !ini!u! thickness "or the clindrical shell #e"ore the corrosion allo+ance is .%1!! and the resulting thickness a"ter the corrosion allo+ance is .,1!!.
!rrange*ent of +ressre vessel and t$+e of do*ed head and end closre [12]
7igure 2 %orrispherical head :10;
-he !ini!u! thickness o" a torrispherical head (th) can #e deter!ined #4
P R $ th
2 (3 −0.2 P
S c
.%!! 1
A
4
( S
√
R, ' , )
1.% -he channel co5er thickness is calculated "ro! the "or!ula o"
D √ + 1 P t %% = + ( 10 %.,1!! 9essel "ead :eight oad [12]
Aith car#on steel clindrical 5essel and doo!ed ends: the esti!ated 5essel +eight is AV %0V!(2VS0.7!)t
11.,%kJ
Aeight o" tu#e plates4
π 2 × ( D, ) =¿
Plate area
4
1.6 !
Aeight o" a plate 1. 3 plate area 1. $ 1.6 1.% kJ Jo. o" tu#e plates 1 Aeight o" total nu!#er o" plates 1.% kJ be sheet thicness [12]
-u#e sheet is "i$ed +ith shell and channel to "or! #arrier "or the process "luids in shell and tu#e side. It is a circular "lat plate +ith drilled holes in regular pattern +hich !ight 5aries "or e5er tu#e sheet laouts. Open end o" tu#es are connected to the tu#e sheet and usuall the tu#e sheets are attached # +elding or #olting or co!#ination o" #oth. -he !ini!u! tu#e sheet thickness +hich according to -@< standard to resist #ending is calculated through4
t ts =
F/ ) 3
√
P k(
1%.1,!!
Ahere F is taken as 1 "or "loating tpe tu#e sheet and !ean liga!ent e""icienc k is co!puted # 0.907 2
k1G
P ( T ) do
0.%
7*+inge*ent +lateGs re;ire*ent [12]
It is usuall installed on the tu#e side o" a #undle +hich ser5es to slo+ do+n and disperse the "luid as it enters the e$changer. It helps in prolongs the li"espan o" the tu#es and as +ell as the #undle. -he re9uire!ent "or the installation o" i!pinge!ent plate is gi5en #4
ρ μ
2
1
ρ μ
2
%0%1.1
Ahere
ρ is the densit o" caustic soda +hile
μ is the tu#e 5elocit
-he calculated 5alue is %0%1.1: +hich is greater than 1. I!pinge!ent plate is re9uired and the thickness +ill #e 6!! according to usual standard. /o==les si=e [12]
Fro! [1]: +ith shell I M than 1 ! it is reco!!ended to ha5e no//le I o" 0.% ! @asets [12]
Qasket is designed in the +a to !ake the !etal to !etal sur"aces leak proo". -he de"or!ation o" gaskets under load seals the sur"ace irregularities #et+een !etal to !etal sur"aces +hich pre5ents leakage o" the "luid. -o pre5ent the leakage o" the internal "luid: the residual gasket "orce !ust #e larger than calculated "orce or re9uired. -he e9uation is presented #elo+ "or the scenario !entioned4
D4/ D 5/
√
6 − )m 6 − ) ( m+ 1)
1.006 Ahere IQ s S 0. -he gasket "actor ! is taken as "or corrugated !etal +ith as#estos "ill "ro! the ta#le o" stated in [1] due to its a#ilit to +ithstand in high te!perature +hereas ; is stated to #e .7, "or !a$i!u! design
D4/ seating stress +ith the re"erence o" gasket "actor. Fro! the calculated 5alue o"
D 5/
IQ o" 1.%! the gasket +idth can then #e deter!ined +ith "or!ula o"
( D4/− D 5/ ) Qasket +idth: J
2
%.66!! -ake 10 !! as the design "or standard +idth 6olt design [12]
-he !ini!u! initial #olt load at at!ospheric pressure and te!perature is gi5en # A!1
π #Q; 10%. J
=¿
1.006 and
-he gasket is co!pressed under tight pressure and the re9uired #olt load A
π 2 /
A! 2 S 2p π #Q!p S
4
!
is gi5en #
p ,0.0J
( D4/ + D 5/ ) Ahere Q !ean gasket dia!eter:
2
1.%%!
N Easic gasket seating +idth # o
2
"or "lat "lange: thus # 0 10!!
ini!u! #olt cross sectional area
$m 1 10.1 !! ( a
16 no!inal thread dia!eter +ith #olt circle dia!eter ( #) o" 1%,0!!: 6 #olts and !! #r >la+.resource.org>pu#>in>#is>'07>is.%76%*%7,0.167.pd"
Ab ( b ini!u! gasket +idth: J !in
2 π6/
1.006
Flange [12]
For gasket seating condition (no internal load applied)
( Am + A b) ( a A
7,76.%J
2
o
M (
$ ( +b−/ ) 2
7%1 J!!
Flange "orce calculation (For operating condition) 2
π . ρ 2drostatic end "orce "or the inside area o" "lange: 2
Ahere E outside shell dia!eter 1%.0,!!
(+b− . ) h
2
1,.%6 !!
o!ent due to 2 : 2h 11 J!!
4
,,601.67J
Qasket seating condition: 2 Q A G 2 706.1 J -aking A A ! o!ent due to 2 Q: Q 2QhQ 1%.J
(+b−/ ) hQ
2
1.00,6 !!
Q 2QhQ 170.% J!! Pressure "orce on the "lange "ace: 2 - 2 * 2 .%J h-
(( # D + #/ ))/ 2
16.%!!
- 2-h- 76%%.,7 J!! 'u!!ation !o!ents under operating condition: " S - SQ 76%%.7 J!! o
Fro! the calculated 5alue o" 76%%.7 J!! it sho+ed that
M ( is the controlling !o!ent as it is
greater than " . Flange thicness [12]
-"
C
√
o
M ( 6
( ( a . .1%!!
A . "ro! graphH < is 11 "ro! chosen #olt +hile E dia!eter o" shellH hence C 1.06!!
H ; 1.06
Saddle s++ort [3]
2ori/ontal heat e$changer is usuall supported # at least t+o supporting saddle supports and assu!ing that the heat e$changers is uni"or!l laded: appro$i!atel 1 percent o" the length o" 5essel +ill #e placed at each end. Fro! the chart gi5en in Figure 1.6 in []: the di!ension o" the 5essel is reco!!ended according to the design is gi5en as #elo+4 -a#le 7 'tandard skirt di!ension Vessel ia. a$. Aeight
i!ensions (!)
! 1.
kJ 170
V 0.,7 !!
; 0.0
1.0 ? 0.6
@ 0.% Q 0.1%
t t1 Eolt dia. Eolt holes. 1 10 % 0 *
4.1 Mechanical Draing
!igure 3 Mechanical design of heat e"changer
HE411 Heat
@9uip!ent Jo.
23*10
HE411 Heat Exchanger S+ecification Sheet
@9uip!ent Jo.
Functional escription -pe o" 2eat @$changer Orientation Operation 'hell 'ide Fluid -u#e 'ide Fluid -otal 2eat ut O5erall 2eat -rans"er oe""icient 2eat -rans"er
Fluid ass Flo+ Late o!position
-e!perature Pressure (as in ';'<) ensit 2eat apacit -her!al onducti5it Viscosit 'hell Inner ia!eter Jo. o" Passes Jo. o" Ea""les Eundled ia!eter -otal Jo. o" -u#es Jo. o" -u#es per Pass -u#e Outer ia!eter -u#e Inner ia!eter -u#e =ength Pitch ia!eter Pressure rop aterial o" onstruction
23*10
'heet Jo.
1
@eneral "ata -o trans"er heat "ro! 5apor in order to heat up spent li9uor 'hell and tu#e: "loating head tpe 2ori/ontal ontinuous Vapor 'pent li9uor O+erating "ata 7.0 kA 16., A>!T 111.70 ! 5erfor*ance of one Bnit Shell Side be Side Vapor 'pent li9uor 1.1, 10%.% kg>s 2O (5) 1.00 2O 0.7776 -otal JaO2 0.061 ol "raction Other o!p. 0.0% 7nlet Otlet 7nlet Otlet 17.6 1.16 10.6 110.70 deg 6.% 101. kPa 1.% 1%,.7 kg>! .1, .6 k?>kg.deg 0.67 0.177 A>!.deg 0.00001 0.000% kg>!s #onstrction of one Shell 1%.0, !! (-pe F: -@< 'tandards) 1., ! 06 . !! 1.,6 !! ,.% !! ,.,7 !! (-riangular Pitch
Prepared #
Cel5in -an Chai ;ik
ate4 ,>11>01%
hecked #
Vincent -an Cok ;e+
ate4 ,>11>01%
-a#le 2eat e$changer speci"ication sheet (ritical re5ie+ o" heat e$changer is pro5ided at part E o" the report in section .0 +hich is co!#ined together +ith "lash tank due to space li!it)
Part 1.0 Introduction (Flash Vessel) In alu!ina re"iner plant: "lash train 5essels are co!!onl used e9uip!ents in digestion "acilit +hich ai!s to let do+n the pressure o" the digester discharge slurr strea! ('*01) into at!ospheric pressure # !ean to "lash cool the slurr and to !ake the slurr concentrated. -he high pressure slurr enters the lo+ pressure "lash tank F-*101 leads to the "or!ation o" li9uid slurr and stea!. In the "lashing process: slurr +ill #e cooled do+n through the e5aporation o" stea! +hile the heat "ro! the stea! +ill #e used in 23*10 "or heating up the spent li9uor. -he "lash tank design in the report is ai!ed to +ork out the re9uired di!ension o" 5essel in ter! o" height and dia!eter to handle the a!ount o" slurr "eed to the 5essel: position o" the slurr entr no//le: 5apor outlet no//le and as +ell as 5essel arrange!ent. 2o+e5er: the constraint "or the design is to ensure !ini!u! slurr carr o5er +ith the outgoing 5apor: su""icient hdraulic head "or the transportation o" "luid "ro! tank to tank +hich need to co!pro!ise +ith the costing o" ele5ation construction and +ind loading. 'u""icient hdraulic head to transport the slurr "ro! tank to tank through the interconnecting "lash piping is not enough as the pressure drop in pipeline !ight induce !ultiphase "lo+ +hich +ill lead to erosion and pipeline +ear [].
1.1 Scope of #or$ Process si/ing o" "lash tank: operational design and as +ell as !echanical design are presented in the report.
2.0 Process Design -he "lash tank F-*101 is to "lash cool inco!ing slurr "ro! te!perature o" 1% o to 17.6o. -he operating condition in the "lash tank is 6.%kPa.
2.1 Design methodology -o ensure proper si/ing and high per"or!ance o" "lash tank the design !ethodolog is proposed as "ollo+s4 1 %
eter!ination o" ter!inal 5elocit and #uoanc Aork out the condensate 9ualit "actor onducti5it o" caustic calculation ia!eter and height o" "lash 5essel Pre"erred "lash 5essel tank orientation and inlet outlet entr
2.2 asic Design Data 5ara*eter ass "lo+rate (kg>s) Pressure (kPa) ensit (kg>! ) -e!perature ( o) Vapor Fraction =i9uid Fraction 'olid Fraction 2eat ut (k?>h) Po+er (kA)
S10 11.1 0.0 11. 1% 0 0.6 0.0% .,6@10 *10%%6.76
S2 117.7 6.% 1,,.,7 17.6 0 0.6 0.0% .,@10 *106171.,
S21 1.1, 6.% 1.% 17.6 1 0 0 6.@7 *1,%7.0,
o!!ent4 -he percentage o" slurr "lashes to 5apor is 1.0 +ith the output o" 1.1, kg>s o" 5apor at '01. oreo5er: it can #e seen "ro! the strea! ta#le that the te!perature o" '01 is #eing reduced # %.6% due to the ther!al energ release +ith the 5apori/ation o" 5apor. -hus: the process si/ing o" "lash 5essel ha5e to take into the considerations that the o#8ecti5e o" at least %.6% te!perature reduction: "lo+ rate o" slurr and 5apor at the outlet and inlet can #e achie5ed +ith the di!ension and operating condition o" "lash tank designed.
2.3 Process design calculation Flash tan si=ing [H!#H]
-he #uoanc is taken into consideration o" li9uid #uoanc "orce that e$ert up+ard onto the 5apor droplet. 2ence: in order "or 5apor to "lash: the 5apor !ust ha5e #uoanc "orce greater than gra5itational "orce. -he #uoanc e9uation is deter!ined as "ollo+s4
ρ L − ρ7 6o$anc$
ρ7
1277.78 −1.42
1.42
77.7
For 5apor to "lash +ithout carring o5er the li9uid droplet: it is 5ital to calculate ter!inal 5elocit o" 5apor. -he ter!inal 5elocit is the "orce #alance on the li9uid droplet and +hen the scenario o" net gra5it "orce #alance the drag "orce happens: the hea5ier li9uid +ill settle at constant ter!inal 5elocit. -hus: it is i!portant to ensure that 5elocit o" 5apor is less than the ter!inal 5elocit to !ini!i/e the carro5er o" li9uid # 5apor and "or the ease o" hea5ier li9uid settle out at the #otto! o" tank. -he e9uation "or ter!inal 5elocit is calculated #4 er*inal velocit$
$a t
ρv
πD
2
0.,
4
It is gi5en # 2<-2 as the guideline that the ter!inal 5elocit is 0.,.
ondensate 9ualit "actor is to deter!ine the purit o" 5apor "lashed at the 5apor outlet. It is 5ital to ensure that the 5apor does not conta!inate +ith slurr droplet as li9uid carr o5er # 5apor +ill reduce the heat e$changer per"or!ance at do+nstrea! and da!age the e9uip!ent at shell side (prone to corrode due to alkaline !ediu!). -he e9uation is deter!ine #4 #ondensate Dalit$ Factor
k
1 √ .
0.7
√ 898.85 0.0
-he e9uation #elo+ presented the conducti5it o" caustic in the "lash 5essel. It is a 5apor purit para!eter to consider as high caustic content (characteri/e # high conducti5it) +ill pose high chances in conta!inating the 5apor strea!. -he caustic concentration is o#tained # ';'< +ith the 5alue o" 1,0 kg>!. arget #ondctivit$ ∅
8+k √ ρa
45 170 0.023
1%,.6
√ 1.42
μs / %m
-he calculated 1%,.6 target conducti5it is reasona#le and sho+ing the calculation is on the right track. -his is #ecause 2<-2 suggested the target conducti5it 5alue o" 00
μs / %m .
"ia*eter
Aith the deter!ination o" target conducti5it and caustic concentration in "lash tank: !ass "lo+ rate o" 5apor: the dia!eter o" the "lash 5essel is then calculated # e9uation as "ollo+s4
√
4
$ π a
8% ∅
1
ρa √ ρ L − ρ a
√
4
13.17
π
45 170
1
147.65 1.42 √ 1277.78 − 1.42
%.1% !
Height
-he deter!ined dia!eter %.1%! is then su#stitute into e9uation #elo+ to deter!ine the total height o" "lash tank.
H D 7 va)
.
2 . $ %.1% $ 0., ,. ! 2eight o" slurr pool is 0 o" total height o" 5essel
0.$ ,. 1.%!
3.0 Operational Design .1 ontrol 'ste! -he "lash tank control sste! is #asicall !ade up o" t+o control sste!. Pressure controller sste! +ill detect 5ariation in 5essel pressure and !ake ad8ust!ent to the 5al5e to pressure relie" it. For le5el control sste!: le5el indicator controller +ill detect 5ariation in le5el and !ake ad8ust!ent to the control 5al5e V*0. =o+ le5el alar! +ill ring +hen the le5el in the 5essel is too lo+: action +ill #e per"or!ed on V*11 to close the 5al5e in order to +ait "or slurr #uild up in "lash tank. Pressure relie" 5al5e is installed at the top o" tank in case o" e!ergenc. rainage 5al5e V*1: V*1 and V*16 are pro5ided "or !aintenance purposes. Isolation 5al5es are installed on inlet and outlet strea! o" line to #pass the slurr +hen the control 5al5e is !al"unction. Le"er to the diagra! #elo+ "or the control sste!.
Figure % Piping and Instru!entation diagra! "or "lash tank
3.2
perating procedure
3.2.1 ommissioning o!!issioning procedure is i!portant to #e conducted prior starting up e9uip!ent "or sa"et and 9ualit assurance. -he usual procedure "or co!!issioning is carried as "ollo+s4 O+erational chec ot list +rocedre []
1. 9ocate all the instrumentation according to PID in the plant. . heck the control 5al5e: glo#e 5al5e: drain 5al5es: 5ent or relie" 5al5e to ensure the are installed properl . Le5ie+ o" all piping connection "or an stea! tracing or an deposit. %. heck "or the #pass line installation around the pipeline o" the e9uip!ent to ensure it is alread #een installed.
H$drostatic test [-]
1. It is carried out on the "lash tank to pro5e the strength o" the !aterials and +eld integrit a"ter construction had #een co!pleted. . =ocate the pressure +ithin a sealed 5essel. . Fill the 5essel +ith inco!pressi#le "luid like +ater %. 'u#8ect the pressure to a kno+n internal pressure +hich is tpicall 10 than the !a$i!u! operating pressure "or hoursH the large internal pressure applied +ill cause the e$pansion o" the 5essel. . Lead the instru!entation that attached to the pressure to deter!ine the total and per!anent e$pansion that the test cha!#er (e$ternal) undergoes. 6. arr out phsical and 5isual inspection to deter!ine the condition o" the 5essel #eing tested. ,. I" the 5essel did not pose an da!age or #eing per!anent distorted due to test pressure: then the e9uip!ent can proceed to start up procedure. Start +
1. . . %. . 6. ,.
@nsure the "lash 5essel is totall e!pt and "ree o" an "oreign o#8ects. Flush the un+anted !aterial in the 5essel using slurr and drain the +astes 5ia drain 5al5e i" the 5essel is not e!pt @nsure the 5essel is connected to all the utilities and check "or an possi#le loosen pipe connection to the 5essel to pre5ent leakage o" slurr. @nsure the te!perature: pressure and le5el sensors attached to the 5essel "unctioning properl. Lun the utilities and ensure the operating condition like pressure and slurr pool le5el in 5essel is achie5ed through the control sste! onitor the "lash 5essel "or a#out 0 !inutes to check "or an unusual acti5ities. I" e5erthing is under good operating condition: "eed the slurr into the "lash colu!nH other+ise check "or an issue that li!it the desired operating condition "ro! #eing achie5ing.
Sht do
1I" the operation is to #e shut do+n: it is reco!!ended to close the "eed 5al5e to stop "eeding the 5essel. -urn o"" all the operating s+itches. rain o"" the slurr "ro! the "lash 5essel and 5ent o"" the possi#le 5apor #uild in the 5essel. %@nsure the 5essel is totall e!pt. 'lo+l depressuri/ing the 5essel to at!ospheric pressure # turning on the relie" 5al5e. 6'hut do+n all utilities connection. ,
1. ontrol the "lo+ !eter so that 11.1 kg>s is achie5ed in the "eed strea!. . @nsure the slurr le5el in "lash tank is al+as !aintained at the re9uired le5el and as +ell the pressure in 5essel is constant at 6.% kPa.
. @nsure the slurr inlet te!perature to "lash tank is o" 1% o to ensure opti!u! "lashing o" 5apor under desired operating pressure in "lash tank as te!perature +ill change the V=@ e9uili#riu! o" "lash pressure. %. arr out close !onitoring to the "lash 5essel operating condition and check "or an unusual acti5it. . Per"or! e!ergenc shutdo+n procedure i" serious pro#le! arise to the operating 5essel and hard to sol5e it. E*ergenc$ sht do
In an e5ent o" e!ergenc shutdo+n: recogni/ed the 5essel alar!s and acted upon. 1. . . %.
-ake i!!ediate action i" e$cessi5e te!perature: pressure or lo+ li9uid le5el is o#ser5ed. 'top the "eeding o" slurr into the 5essel. Open the drain and 5ent 5al5es to release the caustic li9uid and as +ell as depressuri/ing. Jo entr or +ork should #e done on the "lash 5essel #e"ore the 5essel is "ree o" slurr and depressuri/ed.
)aintenance and cleaning *easre
=eakage o" corrosi5e alkaline slurr "ro! "lash 5essel or pipeline is ha/ardous to en5iron!ent. Ahene5er: a spill or leakage is "ound4 1. It is ad5isa#le that the +orkers +ear protecti5e personnel e9uip!ent to protect the!sel5es "ro! the li9uid. . heck "or the si/e o" the leak and per"or! clean up action as according to -a#le 6. . I!!ediate action carried out # !aintenance tea! to "i$ the #roken pipeline or e9uip!ent. %. Isolate the "lo+ o" slurr into the a""ected pipeline or e9uip!ent. .
3.3 !aety !tudy (#A$ID/
3.3 !aety !tudy (#A$ID/ H!?!>" 7"
H!?!>" #!E@O>A %@B7"E:O>"&
1
Jatural isasters
H!?!>" "ES#>757O/ C H!?!>"OBS E9E/
@$tre!e heat
#O/SEDBE/#ES
Pressure #uild up in F-*101 2eat stress o" personnel
5>E9E/7O/ C "EE#7O/ C 6!>>7ES
'hut do+n operation
>7S !SSESS)E/
>E#O))E/"!7O/S
7E7HOO"
#O/SEDBE/#E SE9E>7A
>!/7/@
Possi#le
=o+
=o+
@5acuate personnel "ro! e$tre!e heat
Pipeline an e9uip!ent ther!al e$pansion
@$ternal @""ects
ropped o#8ects
F-*101 operate higher than operating te!perature o" 17.6N a!age o" F-*101 Possi#le rupture o" F-*101: thus release o" corrosi5e caustic
@$ternal @""ects
Fatigue> cracking
Lupture o" pipeline
Inspect regularl "or o5erhead e9uip!ent and possi#le loose ite!s.
nlikel
ritical
@$tre!e
J><
nlikel
a8or
2igh
racking o" F-*101 shell
%
2u!an Factors
I!proper> inade9uate training
J><
Possi#le
ritical
@$tre!e
ontrol 5al5e V*01 "ailure
@$plosion Jo heat e$change ("ail to open)
6
,
Process psets
Process psets
Flo+ de5iation
Pressure de5iation
Insu""icient te!perature to digest #au$ite ore F-*101 o5er pressuri/ed and rupture
@nsure rigging is in good condition and operated correctl
Aearing protecti5e hard hat and as +ell as personal protecti5e e9uip!ents Per"or! non destructi5e testing (J-) on 5essel to test 5essel thickness and pipeline integrit
Pro5ide ade9uate training "or operators
procedure ha5e to #e strictl o#eed
Process psets
orrosion> erosion
tilities Failures
=oss o" po+er
=oss o" "unctionalit o" cascade control sste!s Pressure #uild up in F-*101 =oss o" alu!ina
Operators to o#e
the rule and regulations "ro! the operating !anual
2igh
Process engineering tea! to design and Install isolation 5al5es around !aintenance tea! 5al5e V*01 "or !aintenance o" to install #pass #roken V*01 and isolation 5al5es
J><
=ikel
oderate
2igh
Installation o" "lo+ control sste! at the outlet strea! o" spent li9uor
Possi#le
ritical
@$tre!e
Installation o" e!ergenc shutdo+n 5al5e and high te!perature alar!.
=ikel
a8or
@$tre!e
Visual inspection on the pipeline "or an possi#le de"ects.
Lelie" 5al5e V*0%
Jickel allo steel !aterials "or all the pipelines and tu#e side o" F-*101
Install #pass 5al5e to the control 5al5e
Fre9uent non destructi5e test "or pipeline and 5essel +all thickness
racking o" 5essel or pipeline
esigners> consultants to pro5ide the training.
a8or
psets to do+nstrea! e9uip!ent
7
aintenance engineering tea! to per"or! the testing and "i$ #roken pipeline or e9uip!ent leakage.
nlikel
=oss o" contain!ent
Personal in8ur or death racking and leakage o" F-*101 and as +ell as inlet and outlet pipelines '01: '00: '01.
O""shore health and sa"et e$ecuti5e to handle all the sa"et re9uire!ent rule and regulations.
J><
F-*101 o5er pressuri/ed ("ail to close) =oss o" contain!ent ("ail to close) Increase in te!perature in F-*101
@lectrical engineering tea! to install alar!s
o!pulsor in preparing operating procedure !anual # designers and the
a!age to e9uip!ent +hich !ight include F-*101
@ 9u ip !e nt >I ns tr u! en ta ti on al"unction
Install high te!perature alar! on and pressure alar! on F-* 101
Visual inspection o" an hairline crack on the e9uip!ent.
Process upset and a#nor!al operating condition
Operators to do te!perature !onitoring
Installation o" sa"et netting a#o5e F-*101
=oss o" contain!ent
=oss o" alu!ina production =oss o" production
onitor the operating te!perature and pressure o" F-*101
Operators to inspect the e9uip!ent and pipeline condition.
In8ur or death o" the +orkers
!#7O/S
Fail open>closed 5al5es
nlikel
oderate
oderate
Eackup generator "or i!portant process e9uip!ent
Process engineering tea! to design and electrician to install the control sste! @lectrical engineering tea! to install e!ergenc shutdo+n 5al5e connected to high te!perature alar! and displa at the indicator
Operators to per"or! the checking periodicall. aintenance engineering tea! to per"or! the testing. @lectrical engineering tea! to install #ackup generator
a!age to e9uip!ent +hich !ight include F-*101
@ 9u ip !e nt >I ns tr u! en ta ti on al"unction
ontrol 5al5e V*01 "ailure
@$plosion Jo heat e$change ("ail to open)
procedure ha5e to #e strictl o#eed
J><
nlikel
a8or
2igh
Install #pass 5al5e to the control 5al5e
Process engineering tea! to design and Install isolation 5al5es around !aintenance tea! 5al5e V*01 "or !aintenance o" to install #pass #roken V*01 and isolation 5al5es
J><
=ikel
oderate
2igh
Installation o" "lo+ control sste! at the outlet strea! o" spent li9uor
Possi#le
ritical
@$tre!e
Installation o" e!ergenc shutdo+n 5al5e and high te!perature alar!.
=ikel
a8or
@$tre!e
Visual inspection on the pipeline "or an possi#le de"ects.
F-*101 o5er pressuri/ed ("ail to close)
6
,
Process psets
=oss o" contain!ent ("ail to close) Increase in te!perature in F-*101
Flo+ de5iation
Process psets
Insu""icient te!perature to digest #au$ite ore F-*101 o5er pressuri/ed and rupture
Pressure de5iation
Lelie" 5al5e V*0%
=oss o" contain!ent psets to do+nstrea! e9uip!ent
7
Process psets
orrosion> erosion
Personal in8ur or death racking and leakage o" F-*101 and as +ell as inlet and outlet pipelines '01: '00: '01.
Jickel allo steel !aterials "or all the pipelines and tu#e side o" F-*101
tilities Failures
=oss o" po+er
=oss o" "unctionalit o" cascade control sste!s
Fail open>closed 5al5es
nlikel
oderate
oderate
Process engineering tea! to design and electrician to install the control sste! @lectrical engineering tea! to install e!ergenc shutdo+n 5al5e connected to high te!perature alar! and displa at the indicator
Operators to per"or! the checking periodicall.
Fre9uent non destructi5e test "or pipeline and 5essel +all thickness
racking o" 5essel or pipeline
the rule and regulations "ro! the operating !anual
Eackup generator "or i!portant process e9uip!ent
aintenance engineering tea! to per"or! the testing. @lectrical engineering tea! to install #ackup generator
Pressure #uild up in F-*101 =oss o" alu!ina
production
#A$OP Pro%ect& Alumina re'ney P+,D -o.& 1 -ode Description& !lash Tan$ !T/11
Date& 2()* -ode -o.& !T/11
0AP ead& el4in Tan hai 5i$
0AP Scribe& 6incent Tan o$ 5eo#
/o.
5ara*eter
@ide
5ossible #ase %s& "eviation
#onse;ence
Safegard %Existing&
>eco**endations
1.
=e5el
Jo
1. Jo "lo+ through inlet '01. . ore "lo+ through li9uid outlets '00. . a8or rupture in 5essel F-*101 that caused loss o" slurr
'lurr cannot #e cooled do+n properl () I!proper separation o" 5apour and slurr () Jo production (1) =oss o" production () =oss o" contain!ent ()
F-*101 shutdo+n procedure (1) =e5el control sste!s =I* 01 and =I 0. =o+ le5el alar!s (==< 0%) Epass 5al5e V*0 around I* (1)
Per"or! regular inspection and !aintenance onto the e9uip!ent.
.
=e5el
=ess
1. =ess "lo+ through inlet '01. . ore "lo+ through li9uid outlets '*0. . Lupture in 5essel F-*101.
Leduced product 9ualit () Jo production (1) =oss o" production () =oss o" contain!ent () 'lurr cannot #e cooled do+n properl (1:) !proper separation o" 5apour and slurr ()
'a!e as 1.
'a!e as 1.
.
=e5el
ore
1. ore "lo+ through inlet '01. . =ess "lo+ through li9uid outlets '00.
Leduced product 9ualit (1:) =i9uid carr o5er # 5apour to outlet '01. (1:) 'lurr cannot #e cooled do+n properl (1:) I!proper separation o" 5apour and
'a!e as 1. =i9uid outlet #pass 5al5es V*11 through I*1.
'a!e as 1.
!ction *@lectrical @ngineering to install alar!s *Process engineering to install #pass 5al5e *Operator to per"or! regular inspection *aintenance tea! to repair the #roken e9uip!ent. 'a!e as 1.
'a!e as 1.
production
#A$OP Pro%ect& Alumina re'ney P+,D -o.& 1 -ode Description& !lash Tan$ !T/11
Date& 2()* -ode -o.& !T/11
0AP ead& el4in Tan hai 5i$
0AP Scribe& 6incent Tan o$ 5eo#
/o.
5ara*eter
@ide
5ossible #ase %s& "eviation
#onse;ence
Safegard %Existing&
>eco**endations
1.
=e5el
Jo
1. Jo "lo+ through inlet '01. . ore "lo+ through li9uid outlets '00. . a8or rupture in 5essel F-*101 that caused loss o" slurr
'lurr cannot #e cooled do+n properl () I!proper separation o" 5apour and slurr () Jo production (1) =oss o" production () =oss o" contain!ent ()
F-*101 shutdo+n procedure (1) =e5el control sste!s =I* 01 and =I 0. =o+ le5el alar!s (==< 0%) Epass 5al5e V*0 around I* (1)
Per"or! regular inspection and !aintenance onto the e9uip!ent.
.
=e5el
=ess
1. =ess "lo+ through inlet '01. . ore "lo+ through li9uid outlets '*0. . Lupture in 5essel F-*101.
Leduced product 9ualit () Jo production (1) =oss o" production () =oss o" contain!ent () 'lurr cannot #e cooled do+n properl (1:) !proper separation o" 5apour and slurr ()
'a!e as 1.
'a!e as 1.
.
=e5el
ore
1. ore "lo+ through inlet '01. . =ess "lo+ through li9uid outlets '00.
Leduced product 9ualit (1:) =i9uid carr o5er # 5apour to outlet '01. (1:) 'lurr cannot #e cooled do+n properl (1:) I!proper separation o" 5apour and
'a!e as 1. =i9uid outlet #pass 5al5es V*11 through I*1.
'a!e as 1.
!ction *@lectrical @ngineering to install alar!s *Process engineering to install #pass 5al5e *Operator to per"or! regular inspection *aintenance tea! to repair the #roken e9uip!ent. 'a!e as 1.
'a!e as 1.
slurr (1:) %.
Pressure
=ess
1. =ess pressure in inlet line '01. . =ess pressure in li9uid outlets '00. . Pressure relie" 5al5e V*0% "ails to close co!pletel %. inor rupture in F-*101. . Pressure controller P*0 "ails to close 5al5e V*0,.
'lurr not e""ecti5el cooling do+n (1:). Ine""icient in "lashing (1) . ultiphase "lo+ occurs (). =i9uid hard to "lo+ "ro! one ta nk to another (). =oss o" production (%) =ead to de"or!ation o" 5essel (:%:) =oss o" contain!ent (%).
=e5el control Pressure controller
losel !onitor the pressure in the "lask tank. Install Vent. 'a!e as 1.
.
Pressure
ore
1. ore pressure in inlet line '01. . ore pressure in li9uid outlets '00. . Pressure relie" 5al5e V*0% "ails to open %. ore pressure in gas outlet line '*1.
Increase the te!perature o" slurr (1: ). -ransportation "lo+ issue o" slurr "ro! one tank to tank (). Lupture in F-*101 (1:::%) Leduced product 9ualit (1:::%)
'a!e as %.
6.
Flo+
Jo
1. Jo "lo+ in Inlet line '*1. . Jo "lo+ in li9uid outlets '00. . Jo "lo+ in gas outlet line '01.
Jo production (1::) Euild o" li9uid in F-*101 () Pressure #uild up in F-*101 ()
,.
Flo+
=ess
1. =ess "lo+ in Inlet line '*1. . =ess "lo+ in li9uid outlets '00. . =ess "lo+ in gas outlet line '01.
=e5el control sste!s =I* 01 and =I 0. Pressure relie" 5al5e V*0% (1:%) Pressure controller P*0 (1:%) anual #pass o" LV*01 +ith V*0 (:%) F-*101 shutdo+n procedure (1:::%) 2igh pressure alar! to gi5e noti"ication =e5el control sste!s =I* 01 and =I*0 () =i9uid outlet #pass I*1. F-*101 shutdo+n procedure (1::) Pressure relie" 5al5e V* 0% () Pressure control sste! P*0 () =o+ le5el alar! to noti" ()
7.
Flo+
ore
1. ore "lo+ in Inlet line '*1. . ore "lo+ in li9uid outlets '00. . ore "lo+ in gas outlet line '01.
.
-e!perature
=ess
F-*101 shutdo+n procedure (1:::%) =e5el control sste!s =I* 0% and =I*0 () Pressure relie" 5al5e V*0%. ()Pressure control sste! P*0. () noti". Pressure control sste! P*0 (1)
1. =o+ pressure in F-*101. . 2igh pressure inlet strea! '01.
=ess production (1::) Euild o" li9uid in F-*101 () Pressure #uild up in F-*101 () Leduced product 9ualit (1:::%) Jo production (%) =oss o" contain!ent (%) a!age to e9uip!ent upstrea! and do+nstrea! o" F-*101 (1::)
Ine""icient separation ondensation o" 5apour
'a!e as 1
'a!e as %
'a!e as 1
'a!e as 1.
'a!e as 1.
'a!e as 1.
'a!e as 1. 2igh le5el alar! to noti" (). 2igh pressure alar! to noti".
'a!e as 1
Installation o" te!perature control sste! -I*01
'a!e as 1
slurr (1:) %.
Pressure
=ess
1. =ess pressure in inlet line '01. . =ess pressure in li9uid outlets '00. . Pressure relie" 5al5e V*0% "ails to close co!pletel %. inor rupture in F-*101. . Pressure controller P*0 "ails to close 5al5e V*0,.
'lurr not e""ecti5el cooling do+n (1:). Ine""icient in "lashing (1) . ultiphase "lo+ occurs (). =i9uid hard to "lo+ "ro! one ta nk to another (). =oss o" production (%) =ead to de"or!ation o" 5essel (:%:) =oss o" contain!ent (%).
=e5el control Pressure controller
losel !onitor the pressure in the "lask tank. Install Vent. 'a!e as 1.
.
Pressure
ore
1. ore pressure in inlet line '01. . ore pressure in li9uid outlets '00. . Pressure relie" 5al5e V*0% "ails to open %. ore pressure in gas outlet line '*1.
Increase the te!perature o" slurr (1: ). -ransportation "lo+ issue o" slurr "ro! one tank to tank (). Lupture in F-*101 (1:::%) Leduced product 9ualit (1:::%)
'a!e as %.
6.
Flo+
Jo
1. Jo "lo+ in Inlet line '*1. . Jo "lo+ in li9uid outlets '00. . Jo "lo+ in gas outlet line '01.
Jo production (1::) Euild o" li9uid in F-*101 () Pressure #uild up in F-*101 ()
,.
Flo+
=ess
1. =ess "lo+ in Inlet line '*1. . =ess "lo+ in li9uid outlets '00. . =ess "lo+ in gas outlet line '01.
=e5el control sste!s =I* 01 and =I 0. Pressure relie" 5al5e V*0% (1:%) Pressure controller P*0 (1:%) anual #pass o" LV*01 +ith V*0 (:%) F-*101 shutdo+n procedure (1:::%) 2igh pressure alar! to gi5e noti"ication =e5el control sste!s =I* 01 and =I*0 () =i9uid outlet #pass I*1. F-*101 shutdo+n procedure (1::) Pressure relie" 5al5e V* 0% () Pressure control sste! P*0 () =o+ le5el alar! to noti" ()
7.
Flo+
ore
1. ore "lo+ in Inlet line '*1. . ore "lo+ in li9uid outlets '00. . ore "lo+ in gas outlet line '01.
.
-e!perature
=ess
10.
-e!perature
11.
ain te na nc e
ore
=ess production (1::) Euild o" li9uid in F-*101 () Pressure #uild up in F-*101 () Leduced product 9ualit (1:::%) Jo production (%) =oss o" contain!ent (%) a!age to e9uip!ent upstrea! and do+nstrea! o" F-*101 (1::)
1. =o+ pressure in F-*101. . 2igh pressure inlet strea! '01.
Ine""icient separation ondensation o" 5apour
. %. 1. . . %.
hanges in at!ospheric conditions 2igh te!perature inlet strea! '01. 2igh pressure in F-*101 =o+ pressure inlet strea! '01. hanges in at!ospheric conditions 2igh te!perature inlet strea! '01.
' lu rr is h ar d to " la sh c oo le d.
1. . . %.
r ac ks >l ea ka ge o " 5 es se l F -*1 01 Failure o" inlet 5al5e V*0. Failure o" pressure relie" 5al5e V*0%. Failure o" slurr outlet 5al5e V*11
Le9uired shutdo+n (1:::%::6) Le9uires replace!ent o" F-*101 (1::)
Ine""icient separation ondensation o" 5apour
'a!e as 1
'a!e as %
'a!e as 1
'a!e as 1.
'a!e as 1.
'a!e as 1.
F-*101 shutdo+n procedure (1:::%) =e5el control sste!s =I* 0% and =I*0 () Pressure relie" 5al5e V*0%. ()Pressure control sste! P*0. () noti". Pressure control sste! P*0 (1)
'a!e as 1. 2igh le5el alar! to noti" (). 2igh pressure alar! to noti".
'a!e as 1
Installation o" te!perature control sste! -I*01
'a!e as 1
F -*1 01 s hu td o+ n pr oc ed ur e (1:::%) Pressure relie" 5al5e LV*01 (1) Pressure control sste! P*01 (1) F-*101 shutdo+n procedure (1:::%) E pass 5al5e I* "or inlet 0. Isolation 5al5e V*01: V0 to ser5e the purposes o" !aintenance Pressure indicator on F-* 101 to indicate the 5essel pressure.
Installation o" lo+ te!perature alar! connected to -I*01 Installation o" te!perature control sste! -I*01 Installation o" high te!perature alar! connected to -I*01 'a!e as 1. Pressure indicator on F-*101 to indicate the 5essel pressure.
'a!e as 1
'a!e as 1
10.
-e!perature
11.
ain te na nc e
ore
. %. 1. . . %.
hanges in at!ospheric conditions 2igh te!perature inlet strea! '01. 2igh pressure in F-*101 =o+ pressure inlet strea! '01. hanges in at!ospheric conditions 2igh te!perature inlet strea! '01.
' lu rr is h ar d to " la sh c oo le d.
1. . . %.
r ac ks >l ea ka ge o " 5 es se l F -*1 01 Failure o" inlet 5al5e V*0. Failure o" pressure relie" 5al5e V*0%. Failure o" slurr outlet 5al5e V*11
Le9uired shutdo+n (1:::%::6) Le9uires replace!ent o" F-*101 (1::)
Ine""icient separation ondensation o" 5apour
F -*1 01 s hu td o+ n pr oc ed ur e (1:::%) Pressure relie" 5al5e LV*01 (1) Pressure control sste! P*01 (1) F-*101 shutdo+n procedure (1:::%) E pass 5al5e I* "or inlet 0. Isolation 5al5e V*01: V0 to ser5e the purposes o" !aintenance Pressure indicator on F-* 101 to indicate the 5essel pressure.
Installation o" lo+ te!perature alar! connected to -I*01 Installation o" te!perature control sste! -I*01 Installation o" high te!perature alar! connected to -I*01 'a!e as 1. Pressure indicator on F-*101 to indicate the 5essel pressure.
'a!e as 1
'a!e as 1
4.0 Mechanical design For !echanical design: the "lash colu!n is designed as a thin +alled pressure 5essel under internal pressure. -he !echanical design "or the 5essel proposed +ill #e #ased on the data in process calculation and +ith so!e sa"et consideration added to the design te!perature: pressure: !aterial o" construction and corrosion allo+ance. -he co!ponents to #e designed as listed as "ollo+s4 1 Orientation o" pressure 5essel -pe and thickness o" head and end closure ini!u! +all thickness "or the clindrical pressure 5essel #od % ead +eight o" 5essel
4.0 Mechanical design For !echanical design: the "lash colu!n is designed as a thin +alled pressure 5essel under internal pressure. -he !echanical design "or the 5essel proposed +ill #e #ased on the data in process calculation and +ith so!e sa"et consideration added to the design te!perature: pressure: !aterial o" construction and corrosion allo+ance. -he co!ponents to #e designed as listed as "ollo+s4 1 Orientation o" pressure 5essel -pe and thickness o" head and end closure ini!u! +all thickness "or the clindrical pressure 5essel #od % ead +eight o" 5essel
Verticall "lash 5essel is e!ploed due to the reason o" lo+ "eed capacit: lo+ li9uid hold up ti!e +here the residence ti!e is not the !ain "actor in alu!ina re"iner. -he orientation "a5or the transport o" "luid "ro! one tank to another # !ean o" gra5itational "orce and pressure di""erential. onical #otto! head are used in the design as it is generall "or lo+ pressure application .6% #ar and e$cessi5e !aterial thickness are a5oided.
t
)D ( 2 (0− ) ) cos ∅
0.2899 4110
( 2 240 1 −0.2899 ) cos 60 !!
ue to ti!e constraint: the design stress "or nickel allo %00 is assu!ed to #e the sa!e as l o+ allo steel. Aith design angle o" 60o as suggested # 2<-2: and 10 e$tra a#o5e calculated te!perature and pressure "or sa"et design purposes: the designed te!perature and pressure is as "ollo+s4 esign te!perature 17.6 $ 1.1 1.0o esign pressure 6.% $ 1.1 7.7kPa 7.7 $ 0.001 0.7 J>!! -he design stress +ith re"erence to te!perature "ro! ta#le 1. %0 J>!!
-he calculated +all thickness "or conical #otto! is !! and +ith corrosion allo+ance: !! S %!! !! lindrical shell
ini!u! +all thickness:
*=
P D 2 ( − P
=
( 0.2899 ) ( 4110 ) =2.48 mm 2 ( 240 )−0.2899
9 6.48 mm )lat*
"ead
For clindrical steel 5essel +ith do!ed ends: uni"or! +all thickness:('innott 001) AV%0V!(2VS0.7!)t %0(1.07)(%.110S$10*)[,.1S0.7(%.11S$10*)]() ,.1J 9 72.52 kN +here4 V1.07 +ith 5essels +ith onl "e+ internal "ittings !!ean dia!eter o" 5essel (iSt) 2Vlength o" clindrical section t+all thickness:!! ! $ ,.1! 10,7.J 9 1.08 kN -otal +eight 1.07 S ,. ,.6kJ !nal$sis of stresses [3]
Figre (
Stresses in a c$lindrical shell nder co*bined loading [3]
.
P D , ( 0.2899 ) ( 4110 ) 2 = = = : 91.88 N / m m # Pressure stresses4 =ongitudinal stresses: 2 t 2 ( 6.48) P D , ( 0.2899 ) ( 4110 ) = = 45.86 N / mm2 : L = 4 t 4 ( 6.48 )
ircu!"erential stresses:
ead +eight stress4
: $ =
$ 7
=
π ( D , + t ) t
73.6 10
3 2
π ( 4110 + 6.48 ) 6.48
=0.878 N / m m ( %om)'*ss,v* )
Eending stresses4 0%110S$6.%7%1.6!! 'econd !o!ent o" area o" the 5essel a#out the plane o" #ending:
5 7 =
π
( D 64
4
o
− D, )=
π
4
64
( 4122.96 − 4110 )=1.78 10 4
4
-otal #ending !o!ent at the plane #eing considered:
M =
F $ 2
2
=
( 2458 ) ( 6.48 ) 2
2
=51606.20 Nm
+here4 na!ic +ind pressure 170J>! ('innott 001) ean dia!eter %.11S(6.%7)$10*%.1!
11
mm
4
=oading(per linear !eter): FA 170$%.1,,.%J>!
Eending stress:
: b =;
( )
M D 5 7
2
+t =
(
51606200 4110 11
1.78 10
2
)
+ 6.48 =; 0.22 N /m m
2
-he resultant longitudinal stress is4
: < =: L+ : $ ;: b : $ ,s %om)'*ss,v* ∧ t#*'*(o'* n*&at,v*: < ( 1)2nd )= 45.86 + 0.878 + 0.22 =47.04 N / mm
2
: < ( do2n2,nd )= 45.86−0.878 −0.22 %6.60 J>!!
( : < ( do2n2,nd ) ,s not tak,n&,nto %ons,d*'at,on s,n%* val1* ,s + v* )
4.04
<1.
Figure 6 Principal stresses on up*+ind side []
Qreatest di""erence #et+een principal stresses 1.77 G %,.0% %%.7% J>!! 'atis"actor since greatest di""erence #et+een principal stresses is #elo+ the !a$i!u! allo+a#le design stress (%0J>!!). Elastic stabilit$ chec %6cling& [3] 4
ritical #uckling stress4
: + =2 × 10
( )
t =2 × 104 Do
(
6.48 4122.97
)
=31.43 N / m m
2
-he !a$i!u! co!pressi5e stress +ill occur +hen the 5essel is not under pressure: 2
: $ + : b= 0.878+ 0.22=1.098 N / m m
'kirt support is to #e designed in the +a that it is a#le to support the !a$i!u! dead +eight load o" the 5essel +hen it is co!pletel "illed +ith +ater.
=s =90 >
For a straight clindrical skirt:
π
(
π 4
2
× ( 4.11 ) × 7.19
)
4
$ $ =) ρ g
1000 × 9.81= 935896.3 N = 935 kN
Aeight o" 5essel ,.kJ -otal +eightS,.100,.kJ Aind loading.7 kJ>!
L + # sk,'t Eending !o!ent at #ase o" skirt: s F+ $ (
)
2
¿ 5.28 ×
(
7.19 + 2 2
)= 2
111.48 kNm
Eending stress in the skirt:
: bs=
4 M s
π ( Ds + t s ) t s D s
=
(
3
4 111.48 10
) 10
3
π ( 4110 + 6.48 ) 4110 × 6.48 3
: 2s (o)*'at,n& )=
2
$ 1007.52 10 = =12.02 N / mm2 : 2s (t*st )= π ( Ds + t s ) t s π ( 4110 + 6.48 ) 6.48
ead +eight stress in the skirt:
=1.29 N / mm
3
72.52 10
π ( 4110 + 6.48 ) 6.48
= 0.865 N / mm
2
a$i!u!
: s ( %om)'*ssv* )= : bs + : 2s =1.29 + 12.02=13.31 N / m m
a$i!u!
: s ( t*nsl* ) =: bs− : 2s =1.29− 0.865 =0.425 N / mm
2
^
2
^
-ake 8oint "actor ? as 0.7. riteria "or design4
: s (t*nsl*) ^
≯
( s 3sn=
0.%≯(%0)(0.7)sin00
0.%≯0%
-he oung !odulus "or lo+ nickel steel is 17%6.0% J>!! at 17o [1]
: s ( %om)'*ssv* ) ^
1.1 ≯
≯
0.125 !
( ) t s
Ds
0.125 ( 185469.04 )
sin =s
( ) 6.48
4110
sin 90 >
1.1 ≯ +here4 ( s ( d*s&n st'*ss ) @(;oungDs !odulus at a!#ient te!perature: J>!!) 'ince #oth constraints are satis"ied: and add % !! "or corrosion the design skirt thickness (ts) is 6.%7S% 10.%7 !! Eoth criteria are satis"ied: add !! "or corrosion: and gi5e a design skirt thickness (ts) o" 1!!.
Figure , -pical straight skirt support design []
6ase ring and anchor bolts [3] -o trans!it loads to the "oundation sla#: #ase ring is tpicall used +ith skirt support. -he anchor #oltDs tensile load +orks to +ithstand e$ternal pressure "ro! o5erturning the 5essel ('innott 001).
Ju!#er o" #olts re9uired: at !ini!u! reco!!ended #olt spacing losest !ultiple o" % 1 #olts -ake #olt design stress 1J>!! s 111.%7 kJ! -ake A operating 5alue ,. kJ 4 M s 1 −$ A b = Eolt area re9uired: N b ( b Db
[
¿ 93.22 mm
]
=
1 12 125
[
600
=10.9
3
4 111.48 10 2.1
3
−72.52 10
]
2
Eolt root dia!eter
√
A b × 4 π
=
√
93.22 4
π
=10.89 mm '!all as it !!
-otal co!pressi5e load on the #ase ring per unit length: 3 3 4 M s $ 4 × 111.48 × 10 30.32 × 10 + = + =10749.61 N / m F b = 2 2 π × 4.11 π D s π Ds π × ( 4.11 )
[
][
]
-aking the #earing pressure as J>!!.
F b -he !ini!u! +idth o" the #ase ring: = #
( %
×
1 3
10
=
10749.61 3
5 × 10
=2.15 mm (si/e is s!all)
1.%7 !! 0!! is the allo+ance space.
Ease ring !ini!u! thickness:
t b= L'
√
3 ´( %
( '
=76
√
3 ( 0.077 ) 140
=3.09 mm
+here4 " r allo+a#le design stress in the ring !aterial: and the #asic design stress is 1%0J>!!
7igure
Flange ring di!ensions []
Figure 7. Figure 'tandard #olt si/e % and di!ensions []
5ressre test [3] Eased on E'00: "or the pro5ing o" the integrit o" 5essel: test pressure o" 0 a#o5e the design pressure is used.. -est pressure1. $ 0.J>!! 0.7J>!! ( T*st )'*ss1'* ) ( t −% ) ( ( n ) 0.38 ( 6.48− 4 ) ( 240 ) = esign stress at test pressure: " a 1.25 t ( P ) 1.25 ( 6.48 ) ( 0.38 ) d
¿ 73.48 N / mm
2
-he 5essel design is 5alid since the calculated design stress ,.%7 is #elo+ the per!issi#le stress %0J>!!.
*.1 Mechanical Dra#ing
Figure 10 Flash tank !echanical design
5.1 ritical e6ie !lash Tan$ -he designed "lash tank is si/ed in 5ertical arrange!ent and it has the dia!eter o" %.1and height o" ,.! and slurr pool height o" 1.%!. -he "lash tank di!ension is relia#le as 2<-2 pro5ided all the in"or!ation needed "or the si/ing. -he !ain concern +ith the "lash tank design is the transportation "lo+ o" "luid "ro! one tank to another. It is to ensure that the hdraulic head does not incur !ultiphase "lo+ in pipeline to !ini!i/e erosion. 2o+e5er: due to ti!e constraint the report did not sho+ the design on hdraulic "luid transport. In addition: the 5al5e si/ing is also has #een ignored due to ti !e !anage!ent pro#le!. odelling o" slurr "lo+ can #e done on the particular "lash tank in order to stud #etter the e""icienc o" the "lash tank and ho+ the "luid #eha5e in the tank.
0eat 7"changer -he design heat e$changer is o" one shell t+o tu#e passes. -he shell side o" the heat e$changer is o" condenser con"iguration +here the "or!ula in5ol5es "or the calculation o" heat trans"er coe""icient and pressure drop are +ith the consideration o" !ultiphase "lo+ (condensing 5apor) happening at the outer tu#e o" shell. 2o+e5er: the design e9uation proposed is not accurate as Cern !ethod is e!ploed. -here are other !ethod like Eell !ethod and ela+are !ethod +hich can #e used "or the si/ing o" heat e$changer as the pro5ide !ore accurate pressure drop and +ith the consideration o" #a""le to shell and tu#e to #a""le leakages and as +ell as #passing. -he proposed design also +ithout consideration o" 5enting non condensa#le air as in actual case there are non*condensa#le air e$ists in heat e$changer that reduce the per"or!ance o" o5erall heater. I" I had to design it again: I +ould take that into consideration and use sophisticated so"t+are to predict the per"or!ance o" heat e$changer.
