CHAPTER 9: AGITATION AND AERATION 9.4 A cylindrical cylindrical tank (1.22m diamtr! i" #illd $it% $atr t& an &'ratin l)l *+al t& t% tank diamtr. diamtr. T% tank i" *+i''d *+i''d $it% #&+r *+ally "'acd ,a##l ,a##l""- t% $idt% &# $%ic% i" &n tnt% &# t% tank diamtr. T% tank i" aitatd $it% a ./0 m diamtr- #lat,lad di"k t+r,in. T% im'llr r&tati&nal "'d i" 4.4/ r'". T% air ntr" t%r&+% an &'n ndd t+, "it+atd ,l&$ t% im'llr and it" )&lmtric #l&$ rat i" .21 m/3" at 1. atm and 25 d C. d dn"ity6 99. k3m/
)i"c&"ity 6 .94 7 184 k3m"
Calc+lat: a. ,. c. d. .
P&$ P&$rr R* R*+i +ir rm mnt nt Ga" H&ld+ ld+' ' a+t a+tr rm ma an n Diam Diamt tr r Int Intr# r#ac acia iall ara ara &l+m &l+mtric tric ma""tran ma""tran"# "#rr c&## c&##icin icintt
Gi)n: DT 6 1.22 m ; 6 131 D T DI 6 ./0 m N 6 4.4/ r'" < 6 .21 m/3"
R*+ird: a. ,. c. d. .
Pm H D/2 a kla
&l+ti&n: a. Nr 6 (99.! (99.!(4.4 (4.4/!(./ /!(./0!82 0!82
d. Intr#ac Intr#acial ial Ara: Ara:
.94 7 184 Nr 6 042-915./4 = 1-
a 60H3 D/2 a6 9.544 3m
Pm& 6 0 (99.! (4.4/!8/ (./0! 85 6 /144.02 ;
. &l+mtric ma""tran" c&##.
>"in *+ati&n 9.5/ &# ?am" @
l 6 4.57184 m3"
Pm6 1/41./21 ;
la 6 4.57184 (9.544!
,. )6 (B34!(1.22!(1.22!82 )6 1.4/ m/ "6 (47 .21! 3 B (1.22!82 6 .10 m3" .2 m3" >"in *+ati&n 9.4 &# ?am" @ H 6 .9 c. >"in *+ati&n 9.42 D/26 4.1/2 7 18/ m D/26 4.1/2 mm
la 6 .451 3"
CHAPTER 9: AGITATION AND AERATION 9.5 E"timat t% )&l+mtric ma""tran"#r c&##icint k @a #&r t% a"li*+id c&ntract&r d"cri,d in Pr&,lm 9.4 ,y +"in a c&rrlati&n #&r k @a and c&m'ar t% r"+lt $it% t% 7'rimntal )al+. Gi)n: Ract&r )&l+m- )6 1.4/m / "6 .10 m3" P6 1/42 ;att" R*+ird: k@a (+"in *+ati&n 9.1 ,y ?am" @! k@a c&m'ard $it% 7'rimntal )al+ &l+ti&n: 1342
k@a 6 .20(
1.43
!.4 (.10! .5 6 .54 " 1
E7'rimntal
E"timatd )al+6 .451 " 1 #&r )&l+mtric ma""tran"#r c&##icint 6
( 0.0548−0.0451 ) x 100 ( 0.0548 )
6 1. rr&r
CHAPTER 9: AGITATION AND AERATION 9.0 T% '&$r c&n"+m'ti&n ,y an aitat&r in an +n,a##ld )""l can , 7'r""d a"
( ) 2
P mo
ρND I = f 3 5 μ ρN D I
Can y&+ dtrmin t% '&$r c&n"+m'ti&n and im'llr "'d &# a 1-all&n #rmntr ,a"d &n #indin" &# t% &'tim+m c&nditi&n #r&m a &nall&n )""l ,y +"in t% "am #l+id "y"tmF I" y&+r c&ncl+"i&n ra"&na,lF ;%y &r $%y n&tF
Gi)n:
( ) 2
P mo
ρND I = f 3 5 μ ρN D I
P 61 all&n" m61 all&n R*+ird: Can t% '&$r c&n"+m'ti&n and im'llr "'d &# P , dtrmind &n #indin" &# t% &'tim+m c&nditi&n #r&m m ,y +"in t% "am #l+id "y"tmF ;%yF &l+ti&n:
V P V m
=1000 T% "cal rati& i" D I , P D I , m
1
= 1000 =10 3
T& ac%i) dynamic "imilarity- t% t%r n+m,r" #&r t% 'r&t&ty' and m&dl m+"t , *+al
[
Pmo 3
5
] [
ρN D I P
=
P mo 3
5
ρN D I
]
m
[ ] [ ] 2
2
ρND I μ
ρND I
=
μ
P
m
>"in t% "am #l+id #&r m&dl and 'r&t&ty'5
( Pmo ) p =10
[ P ]
mo m
ρ P = ρm μ P = μm
[ ] N P
3
N m
T% *+ality &# Ryn&ld" n+m,r r*+ir" N P =0.01 N m $%il t% *+ality &# r&+d n+m,r r*+ir" N P
1 =
√ 10
N m
$%ic% "%&$" t$& c&n#lictin c&nc't". I# ρ P ≠ ρm μ P ≠ μm
[]
[]
μ μ 1 = ρ m 31.6 ρ
P
T%r#&r- i# kinmatic )i"c&"ity &# 'r&t&ty' i" "imilar t& $atr- t% kinmatic )i"c&"ity &# t% #l+id $%ic% nd" t& , m'l&yd #&r t% m&dl "%&+ld , 13/1.0 &# t% kinmatic )i"c&"ity &# $atr. It i" im'&""i,l t& #ind t% #l+id $%&" kinmatic )i"c&"ity i" t%at "mall. A" a c&ncl+"i&n- i# all t%r dimn"i&nl"" r&+'" ar im'&rtant- it i" im'&""i,l t& "ati"#y t% dynamic "imilarity.
CHAPTER 9: AGITATION AND AERATION GA HAND@ING ;ITH R>HTON T>RJINE A #rmntr &# diamtr and li*+id %i%t 1.4m i" #ittd $it% a R+"%t&n im'llr &# diamtr .5m and &##,&tt&m claranc ./5m &'ratd at 5 r'm. T% #rmntati&n ,r&t% i" "'ard $it% air at a )&l+mtric #l&$ rat &# .2m/3min. Hal#$ay t%r&+% t% c+lt+r "&m ,arin" in t% "tirrr dri) ,in t& #ail and "tirrr "'d m+"t , rd+cd t& a ma7im+m &# 45 r'm #&r t% rmaindr &# t% 'r&c"". a. >ndr t% n&rmal &'ratin c&nditi&n"- i" t% a" c&m'ltly di"'r"dF ,. A#tr t% "tirrr "'d i" rd+cd- i" t% im'llr #l&&dd &r l&addF Solution: a) Ni 6
75
/ min
( ) 1 min 60 s
−1 1.25 s
2
r 6
¿ Di g
6 1.25" 1
6
2
¿ (0.5 m ) ¿ ¿ ¿
6 .90
&r c&m'lt a" di"'r"i&n l 6 .2
( ) D I DT
0.5
Fr
l: l&&din l&adin tran"iti&n
( ) 0.5 m
0.5
6 .2
1.4 m
0.5
( 0.0796 )
0.5
6 .//
6 lNiDi/ 6 (.//!(1.25" 1! (.5m!/ 6 5.27x10 -3 m3 /s = .2 m /3min K- )&l+mtric #l&$rat &# a" ratr t%an t% &'ratin #l&$ rat- $ can c&ncl+d t%at t% air 'r&)idd i" completely dispersed +ndr n&rmal c&nditi&n".
b)
Ni 6
45
/ min (
1 min 60 s
¿ Di g
6 .5" 1
−1 0.75 s
2
r 6
)
6
2
¿ ( 0.5 m) ¿ ¿ ¿
6 .2
Kl&&dinl&adin tran"iti&n l 6 /
( ) D I DT
3.5
Fr 6 /
( ) 0.5 m 1.4 m
3.5
6 .2/4
6 lNiDi/ 6 (.2/4!(.5" 1! (.5m!/ 6 0.00219 m 3 /s KAt rd+cd "tirrr "'d- ma7im+m air #l&$ rat can , %andld $it%&+t im'llr #l&&din a" &'ratin #l&$ rat (.2m /3min! i" ratr t%an t%i". T% im'llr i" !""#$#.
CHAPTER 9: AGITATION AND AERATION Cl&"tridi+m act&,+tylic+m carri" &+t anar&,ic #rmntati&n and c&n)rt" l+c&" int& act&n- ,+tan&l al&n $it% "mallr c&ncntrati&n" &# ,+tyrat- actat- tc. In #rmntati&n t% #&ll&$in 'r&d+ct" $r &,taind #r&m 1 m&l" &# l+c&" and 11.2 m&l" &# NH /- a" nitr&n "&+rc. Pr&d+ct" #&rmd: Cll" 6 1/m&l" J+tan&l6 50m&l" Act&n6 22m&l" J+tyric acid 6 .4 m&l"
actic acid6 14 m&l" CO 26 221 m&l" H 26 1/5m&l" Et%an&l6 . m&l"
Jy 'r#&rmin a car,&n- nitr&n- %ydr&n- and &7yn ,alanc- dtrmin t% c%mical c&m'&"iti&n &# t% cll". Solution: Jy 'r#&rmin a car,&n- %ydr&n- nitr&n and &7yn ,alanc- dtrmin t% lmnt c&m'&"iti&n &# t% cll". 1C0H12O0 L 11.2 NH /
1/CaH,OcNd L 50C 4H1O (,+tan&l! L 22C /H0O(act&n! L
.4C4HO2(,+tyrat! L 14C2H14O2 (actic acid! L 221CO2 L1/5H2 L . C 2H0O(t%an&l! K $%r C aH,OcNd r'r"nt" lmntal c&m'&"iti&n &# cl&"tridi+m cll" Car,&n Jalanc: 1(0! L 11.2(! 6 1/(a! L 50(4! L 22(/! L .4(4! L 14(2! L 221(1! L .(2! : a 6 4.40 Hydr&n Jalanc: 1(12! L 11.2(/! 6 1/(,! L 50(1! L 22(0! L .4(! L 14(14! L 1/5(2! L .(0! : , 6 10.2 O7yn Jalanc: 1(0! L 11.2(! 6 1/(c! L 50(1! L 22(1! L .4(2! L 14(2! L 221(2! L .(1! : c 6 /. Nitr&n Jalanc: 11.2(1! 6 1/(d! : d 6 .0
C%mical C&m'&"iti&n &# t% cll 6 %&.&'(1'.02"3.*0.'
