1. Effect of Temperature on Transition Velocity from Turbulent Fluidizationto Fast Fluidization in a Gas Fluidized Bed

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^† *

*

(2001 4 26 , 2001 6 5 )

Effect of Temperature on Transition Velocity from Turbulent Fluidization to Fast Fluidization in a Gas Fluidized Bed

Dal-Hee Bae, Ho-Jung Ryu^†, Dowon Shun, Gyoung-Tae Jin and Dong-Kyu Lee

Korea Institute of Energy Research, Daejeon 305-343, Korea

*Dept. of Industrial Chemistry Engineering, Chungbuk National University, Chongju 361-763, Korea (Received 26 April 2001; accepted 5 June 2001)

( !"#: 0.256 mm,

"$%: 2,617 kg/m³)& '() *+(,# 0.02 m, - 2.0 m) emptying time method

(Utr) ./ 0 12. ./3 4 5 657 89 6512. : ;<

./= 0 >? @AB C DEF GH1I C DEFA J Chehbouni K[19] DEF ./=AB 5 L ') MB& NO,P2.

Abstract−Transition velocity from turbulent to fast fluidization has been measured by emptying time method in a high temperature circulating fluidized bed(0.02 m i.d. and 2.0 m high) of sand particle(specific surface mean diameter: 0.256 mm, particle density: 2,617 kg/m³) with variation of temperature(15-600^oC). Measured transition velocity from turbulent to fast fluidization increased with increasing temperature. The previous correlations on transition velocity to fast fluidization compared with the meas- ured values. Among the previous correlations, correlation of Chehbouni et al.[19] shows relatively good results.

Key words: Gas-Solid Fluidization, Transition Velocity, Fast Fluidization, Temperature Effect

†E-mail: hjryu@kier.re.kr

1.

(turbulent fluidized bed)

(fast fluidized bed)8 ,9. # :& -.

/& ; < =8 >?' @AB C =8 ;:

D EF 2 # ;< 2 GH& IJ, ;

./ KLM9. NOP ; QRS H TUV

WX YZ[ \EH] ^ _`8 aM bc ; d ef

g6 NOYV hi j& kl jm ./TUV,

n? opf d fq ?ropf st (u j9[1, 2].

2 x& yZz NO { CE j& ,| '

M w] -./& T NO WX :}4~ 4 W|

(dense-dilute interface) 0m2& P M9[2].

"V v { F& AP ;:(solid concentration)

F& A"V j9. ;: u& AP

=8 { F& A, EF, ;./ >? =

@AB G F& A, E F, ;./ >? = # e >?

F& A, >? = f 1(bulk density)

F& A, >? = # K >?

u F& A, >? =8 Us(1-ε){ F&

flooding point method +"V j"' k{ u

& AP w] -./{ _ w] $ &7 t

& (emptying time){ F { >? =8

F& A(emptying time method), >? = ;

./<(maximum G_s){ F& A, f =

(elutriability) F& A, >? = [

? ;./<(saturated Gs){ F& A, >? = 8 F& A +"V j9. Table

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1P "V v { F& A{ Z q#

j"' ¡¡ FA{ (u, TL~¢{ K£ q# j

m ©2&7 t& (emptying time){ >? = 8 ª f«f >& { "V v "V

F& emptying time method ¬ (u9. 2® f

§ ¢& # ; $ &7¯2 t& { w

°±²³(water manometer) + | ¡´"V µ¶& A

time method H "V v { Ff GH&

9 Fº emptying time{ F3 j& A{ (uH½ ,9.

Table 2& "V v ²¾& ¿ >¢ ÀB

, f§ TL¢{ K£ q# j9. Á5 ÀB

"V Chehbouni +[19] ÂÃ~ ÄW Å =8 Table 1. Methods for determining transition velocity from turbulent to fast fluidization

Type Methods Symbol in Table 4 Authors

Solid concentration Bed expansion versus U 1 Lewis et al.[3]

Yerushalmi et al.[4]

Avidan and Yerushalmi[5]

Schnitzlein and Weinstein[6]

-∆P/∆Z-U-G_s phase diagram 2 Yerushalmi and Cankurt[7]

Horio et al.[8]

Bi et al.[9]

Jiang and Fan[10]

Horio et al.[11]

Adánez et al.[12]

Tsukada et al.[13]

Voidage-U-G_s phase diagram 3 Chen et al.[14]

Li and Kwauk[15]

Kwauk et al.[16]

Perales et al.[17]

Li et al.[50]

Bed bulk density versus U 4 Chehbouni et al.[18, 19]

Pressure fluctuation 5 Leu et al.[20]

Yang et al.[21]

Flooding point method U_s(1-ε) versus U diagram

6 Adánez et al.[12]

Namkung et al.[22]

Entrainment Emptying time versus U 7 Lee and Kim[23]

Shin et al.[24]

Han et al.[25]

Chehbouni et al.[18, 19]

Delebarre et al.[26]

Namkung et al.[22]

Maximum G_s versus U 8 Schnitzlein and Weinstein[6]

Elutriability versus dp 9 Le Pauld and Zenz[27]

Saturated G_s versus U 10 Bi et al.[28]

Entrainment rate versus U 11 Yi et al.[29]

Table 2. Factors influencing on the transition velocity from turbulent to fast fluidization.

Variable increased Effect on U_tr Source

Bed geometry Bed diameter(D_t) Increase Chehbouni et al.[19]

Particle properties Mean particle diameter(d_p) Increase Shin et al.[24]

Han et al.[25]

Jiang and Fan[10]

Particle density(ρ_p) Increase Yerushalmi and Cankurt[7]

Avidan and Yerushalmi[5]

Operating condition Pressure(P) Decrease Tsukada et al.[13]

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39 4 2001 8

H Shin +[24], Han +[25], Perales +[17], Jiang~ Fan[10], Adánez + [12]

& Æ"V È"' Yerushalmi¥ Cankurt[7], Avidan~ Yerushalmi [5]

& Æ"V È9. NONÉ ÀB"V Tsukada +[13]P 0.1-

0.7 MPa ÊG ÂÃ, ~ Å =8

Table 3P "V v { Ìf GH ÍM f§

4µz¢{ K£ q# j9. Î q ¤¥ ¦ $%

tr)¥ _6ÒÓ7n (Ar) ÅV ÎÔ

9. 2® Tsukada +[13] 4µz Õ 4µz¢P 4Y, 4 N É ÂÃÖ ¤×"V ÍM 4µz"V ÏÐÑ ¥ _6Ò Ó7n [ÅM f;1¥ f;¼ >? 0& NÉ Í

M 4µz' 2 z Á5 ØbIÙ(dimensionless group) Á 5V ÎÔf GH f;1¥ f;¼ Ú{ [ÅÛ 4µz9.

Ü, Tsukada +[13] WX& ÀB{ »È"

>?3 WX f;¼& D EF 2' f;1® >?, WXf ÝÞ f;¼ >? Åß »f GH& Y>?

= "V v , ÂÃ~ Åß YÀB

, f§ 4µz¢ Hà , áâ ãK9.

f§ TL¢{ äS´"V - ./TUV NONÉ

~ ¦P Y NÉ, "V v ²¾& Y

ÀB H& M ¤ 0"' ÍM 4µz¢ ÏÐÑ

(Retr)¥ _6ÒÓ7n (Ar) f;1¥ f;¼ Ú [Å

m j" f§ ÂÃ¢P åZ 4Y, 4 ÂÃNÉ æM

~f ÝÞ Y ´u H& ÂÃ~¥ ç

f§ 4µz¢~ ÂÃ~¥ ç, áâ èH "V

ì TL& f; Y >? = "V v

>? Hàf GH $í w]V (u Y

>?Ò "V v { F d ¶È9.

2.

Fig. 1P ì ÂÃ (uM Y ./ ÂÃ¾ q# j

9. v; ¾& 4îµ(riser), ()*, downcomer¥ L-valveV L

m j9. 4îµ~ downcomer& #W 0.02 m, C 2.0 m ïð, àÀµ(quartz tube)"V Íñ downcomer 4å& ()*{

ò¾È9. ?f;V& ef (u"' n²³V F, ó2ô <|(McMillan Co., Model 100-12)V F<m 4îµ å V aõ È9. # ö÷& L-valve èH ; -a

& G¾Vå³ C 0.05 m¥ 1.7 m G¾, ¼{ bÁ

>/f¥ T FÈ9. 4îµ~ downcomer YNø{ G

H 4îµP 4 kW u<{ ù& vf³ 4ú, downcomer& 6 kW

vf³ 2ú (u hÈ"' YNøfV I& Y

2û9. M ;& ()* [üm downcomer¥ L- valve èH 4îµ"V -a9.

ÂÃ (uM & $íV ý\WP 0.256mm, 1(apparent density)& 2,617 kg/m³, þ1 1,222 kg/m³9.

¡ NÉ K k{ Ff GH ÿ ¥ Ø

FM w]{ downcomer G¾, ;Ö aL P } Fig. 1 Q1~ Q2 åZ ef a 4îµ "V ;

./õ È9. 4îµ"V -a& ;<P Q1 <{ >

? Nø3 j9.

I& ~ YNÉ # K af´¹ WB{ E Ý F445V »È"' F445 K ö÷ FÈ9. "V v P Table 1 q emptying

time method u FÈ9. I& ~ YNÉ F

445 29 L-valve èH 4îµ"V -./& ;

M9. 4îµ"V ; -./{ P .å³ H

# ;< ËU # ö÷ ËU, } D EFH]

Ý¯2 { emptying time"V FÈ9[24, 25]. Emptying time

Fº, F{ GH # bÁ >/f¥ A/D converter H ó2ô ö÷V FÈ9. "V v

F{ G, ÂÃP am NÉ 3y o ÂÃ{ èH -Ô

{ ¶È9.

¡ ÂÃNÉ ö÷& >/f(bÁ, validyne, P24D

Model) (u v(±5 V)- ö÷V ¤m Öü|(data

acquisition system, Real time devices Inc., AD2110 Model) D PC È9. ¡ ÂÃNÉ ö÷& 100 Hz aV 10,000ú üÈ9.

Table 3. Summary of correlations on the transition velocity from tur- bulent to fast fluidization

Authors Correlations

Lee and Kim[30] Re_tr= 2.916 Ar ^0.354 Perales et al.[17] Re_tr= 1.41 Ar^0.483 Bi and Fan[31] Re_tr= 2.28 Ar^0.419 Adánez et al.[12] Re_tr= 2.078 Ar^0.463 Tsukada et al.[13] Re_tr= 1.806 Ar^0.458 Chehbouni et al.[19] Re_tr= 0.169 Ar^0.545(D_t/d_p)^0.3

Fig. 1. Schematic diagram of experimental apparatus.

1. Riser 5. L-valve

2. Cyclone 6. Differential pressure transducer 3. Downcomer 7. A/D converter

4. Feed hopper 8. Personal computer

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3.

3-1.

Fig. 2& ì TL emptying time F (uM A{ q#

j9. ì TL& # bÁ >/f u

FÈ9. ª 40¸¯2& 4îµ M ; L-valve èH 4îµ"V 9 a& F445 ö÷ q9.

¿, F445 NÉ 4îµ"V ; -a{ " 4îµ

' 4îµ ËU M9. Fig. 2& F445

å³ ö÷ Ff ñ, } 40¸ { Ýå³ ;

-./Ò2 xP WX ö÷ q# j"' ª } å³ # ËU, } åZ

ö÷ EFH9. ì TL& ËU, } EFH 2f ñ& { emptying time"V FÈ9. >/fV

# K ö÷ F emptying time{ F& AP

| ¡´ µ¶ H F& A H Fº, { F3

j& Æ"V (Ö9. ª q ¤¥ ¦ am NÉ

3y o ÂÃ{ È"' 3y ÂÃ P emptying time P D (È b& 1¸ #È9.

Fig. 3P ¡¡ Y >? = emptying time >?

q# j9. ª q emptying time P 3y ÂÃ ý\

µ# ; $ Ò&7 t& ¹ emptying time

ËU, } ËU WB ?9. f§ q ¤¥ ¦ >? = emptying time ËU f«f >& { "V v , UtrV FÈ9[12, 17-19, 22-26].

3-2.

Fig. 4& 4Yå³ 600^oC¯2 Y>? = "V

9. ¥ ¦P WBP Y>? = >?WB~ µ

Hà3 j9. ²¾& Y ÀB , f

§ TL TL¢ =8 Y =8

ËU,9& [32-38]¥ ,9& [39, 40] d Y ÀB D 09& [41, 42] + V 9 ~ ÍM ¤ j9.

V 9 TL~ H Choi +[43]~ Ryu¥ Choi[44]& Y>

(terminal velocity)¥ ¦_2& W(dpt) >?V F´"V q j9 È9. , dpt & H2& Ú

² m Ì3 j"', Q

"V dpt ËU& ËU Ì3 j9 È 9. Ü, ª¢P $í(ý\W 0.172 mm, 1 2,509 kg/m³) (u F, ÂÃ~ P (0.8 m/s)& Y

Å =8 , ¨ (1.0-1.6 m/s)

& Y =8 ËU, } 9 ', CP (2.1 m/s)

& Y Å =8 | ´"V ËU& Æ"V , ¤ j9.

Fig. 5& ì ÂÃ (u, $í(ý\W 256µm, 1

Fig. 2. Bed pressure drop versus time-emptying time determination.

Fig. 3. Emptying time versus gas velocity-U_tr determination.

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39 4 2001 8

2,617 kg/m³) H ì ÂÃ ÊG¥ YÊG |M dpt

>? q# j9. ª q ¤¥ ¦ emptying time{ F, $% Y Å =8 d_pt ËUÈ"' ~´

"V ì TL ÊG& EF Y Å =8

ËU& Æ{ Ì3 j9. =8 Y

GH& CP ãK, Æ"V (Ö9.

;# & ;& Ú, å d ¨ ñu ' 2 ! H ; ä (terminal velocity) F M9. ä & _í z (1)~ ¦ ÎÔM9.

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f CD& ÂÃ´"V F& Ú|(drag coefficient)'

ÀQ =8 9"~ ¦ ÎÔi j9.

for Re_p< 5.76 (2)

for 5.76 < Re_p< 541 (3)

for 541 < Re_p< 200,000 (4)

Ú|(CD)& Rep

=8 96 ÎÔM9. ~´"V Y>? = ä >

?WBP (CDρ_g) >?V ü£i j"' ÏÐÑ (Rep)

=8 ¡ ÀQ 9"~ ¦ ÎÔM9.

for Re_p< 5.76 Stokes’ region (5) for 5.76 < Re_p< 541 Intermediate region (6) for 541 < Re_p< 200,000 Newton’s region (7)

,, Y Å =8 ef 1& ËU, ¼& , 9. Rep ñP Stokes’ region& CDρ_g f;¼ #V Y =8 éÁ´"V ', Newton’s region& C_Dρ_g f;1 #V Y =8 ËU intermediate region

& CDρ_g (ρ_gµ)^0.5 #', (ρ_gµ)^0.5& Y =8 ËU

U¼{ ¹ } 9 & WB{ ¹9. ~´"V

"V v ~ ¦P CP ÊG(Newton’s region)&

C_Dρ_g f;1 # Y =8 ËUV ä

& ËUV CP "

V v& Æ"V (ÖM9.

+[13] ~ ¥ µ Hà3 j9. EF

& Å =8 f ÝÞ[45-49], P "V v H2& Æ"V (Ö

9.

U_t 4gd_p(ρ_p–ρ_g) 3ρ_gC_D ---

1 2⁄

=

C_D 24 Re_p ---

=

C_D 10 Re_p^{1 2}^⁄ ---

=

C_D=0.43

C_Dρ_g∝µ C_Dρ_g∝(ρ_gµ)^0.5 C_Dρ_g∝ρ_g

Fig. 4. Transition velocity from turbulent to fast fluidization versus tem- perature.

Fig. 5. Effect of temperature on particle diameter whose terminal velocity is equal to the fluidizing velocity.

Fig. 6. Comparison between measured U_tr and calculated values by pre- vious correlations.

symbols: measured values, lines: calculated values

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3-3.

Fig. 6P ì TL Y>? =8 FM "V v

~ f§ 4µz H ÌM ~ ç q# j9.

¡ 4µz Á5& Table 3 q j9. ª q ¤¥ ¦ Chehbouni +[19] 4µz H |M "V v

ì TL FM ~ (È"' 9 4µz¢ H |M ¢P F H ~ Ì9. ¥ ¦P W BP ì ÂÃ (uM ./ ÄW~ µ »3 ãK

j9. Chehbouni +[19]P ÄW Å =8 "V

ÄW ÀB [Åm j9. ì ÂÃ (uM ./ ÄW

P f§ TL¢ (uM ÂÃ¾ H 9U ñf ÝÞ

ÂÃ¾ H ÄW $ ÂÃ, ~ ¤×"V

{ Ì& Æ"V (Ö9. Chehbouni +[19] 4µz ì TL FM "V v { ç´ % Ì&

9 4µz¢~& &t ª¢ 4µz ÄW ÀB{

»'f ÝÞ"V (ÖM9. ~´"V "V v

{ Fº Ìf GH& ÄW ÀB{ Åß »& Æ ´ S, Æ"V (Ö9.

Fig. 7. Comparison between measured transport velocity from turbulent to fast fluidization and calculated values by previous correlations.

: measured values in this study, (a) Lee and Kim[30], (b) Perales et al.[17], (c) Bi and Fan[31], (d) Adánez et al.[12], (e) Tsukada et al.[13], (f) Che- hbouni et al.[19]

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39 4 2001 8

Table 4. Summary of experimental conditions and results of previous studies on the transition velocity from turbulent to fast fluidization

Authors D_t[m] H_t[m] Particles d_p[µm] ρp[kg/m³] Geldart’s group T[^oC] P[kPa] U_tr[m/s] U_tr Determining method^* Yerushalmi and Cankurt[7] 0.152 8.5 FCC

HFZ-20 Alumina

49 49 103

1070 1450 2460

A A B

A.C. A.C. 1.37 2.10 3.85

2 2 2

Chen et al.[14] 0.09 FCC

Alumina Alumina Iron ore Iron ore

58 54 81 56 105

1780 3160 3090 3050 4510

A A B A B

A.C. A.C. 1.25 2.0 2.6 2.0 4.0

3 3 3 3 3

Li and Kwauk15] 0.09 8.0 Alumina 54 3160 A A.C. A.C. 2.45 3

Lee and Kim[23] 0.078 Cement

Raw meal

23.6 2500 A A.C. A.C. 1.80 7

Avidan and Yerushalmi[5] 0.152 8.5 FCC Dicalite HFZ-20

49 33 49

1070 1670 1450

A A A

A.C.

1.40 1.10 1.82.1

1 1 1

Shin et al.[24] 0.0762 2.5 Coal 205

395

1720 1720

B B

A.C.

1.58 2.28

7 7

Han et al.[26] 0.078 2.6 Coal 730

1030

1400 1400

B D

A.C.

1.78 2.09

7 7

Kwauk et al.[16] 0.30 4.0 FCC 58 1780 A A.C. A.C. 1.85 3

Li et al.[50] 0.09 FCC 54 930 A A.C. A.C. 2.50 3

Horio et al.[8] 0.05 FCC

Sand

60 106

1000 2600

A A

A.C. A.C. 0.92 4.50

2

Le Palud and Zenz[27] 0.15 3.25 FCC HFG-20 Alumina

49 49 103

1070 1450 2460

A A B

A.C. A.C. 1.2-1.5 1.7-2.5 3.7-4

9 9 9

Leu et al.[20] 0.108 Sand ~90 ~26000 ~B A.C. A.C. ~2.27 5

Yang et al.[21] 0.224 FCC 67 1700 A A.C. A.C. 1.5 5

Perales et al.[17] 0.092 2.9 FCC Sand

80 120-177 177-250 250-400 250-500 500-750 750-1200

1715 2650 2650 2650 2650 2650 2650

A B B B B B B

A.C. A.C. 1.99 1.69 1.82 3.67 3.63 4.98 6.31

3, 7

Bi et al.[9] 0.102 Polyethylene ~325 660 B A.C. A.C. 2.25 2

Jiang and Fan[10] 0.102 6.32 Polyethylene Polyethylene Glass beads Glass beads

3400 4500 2160 5000

1010 920 2500 2500

D D D D

A.C. A.C. 4.6

5.02 6.99 8.65

2 2 2 2

Horio et al.[11] 0.05 Sand

FCC

106 60

2600 1000

B A

A.C. A.C. 4.50 0.95

2 2

Adánez et al.[12] 0.10 3.9 Sand 170

170 170 170 387 561 710 710 710 710 894 344

2600 2600 2600 2600 2600 2600 2600 2600 2600 2600 2600 2600

B B B B B B B B B B B B

A.C. A.C. 3.05 3.1-3.2 3.0-3.2 3.15 4.40 5.05 5.45 5.60 5.4-5.8 5.6 6.15 4.30

6 2 8 7 7 7 6 2 8 7 7 7

Coal 316

561 710 894

1400 1400 1400 1400

B B B B

A.C. A.C. 3.00 3.60 4.00 4.50

7 7 7 7

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v WB{ Ì3 j" Y =

f«f ç Chehbouni +[19] 4µz WX& Y

= "V v f«f F~ (

, o 9 4µz¢P f«f F H qÇ9.

Fig. 7P ì TL d f§ TL FM "V v

ÂÃÖ¥ Þ( M f§ 4µz¢~ ç q# j 9. ª )@P F{ q#' ä@P ¡ 4µz H |M

{ q# j9. ª q "V v F NÉ d F¢P Table 4 Ftm j9. ì TL d f§ Â ÃNÉ{ ÄW 0.02-0.224 m, f 23.6-4,500µm, 1

660-4,510 kg/m³, Geldart Z A, B d D |, Y 4Y-600^oC,

4-7.0 f¯2V ç´ *P ÊG NONÉ{ [Å j

"V ÂÃÖ¢~ ç èH *P NONÉ

"V v { % Ì& 4µz{ éF3 j9. ª

F{ % Ì3 j"' Y F, ì TL Â Ã~ H +P E¾ q#9.

4.

ì TL ÂÃÊG m *{ K£ 9"~ ¦9.

(1) "V v , Y ÀB { F d ¶f GH Y./ $í w]V (u emptying time method H Y>? =

"V v >? F d ¶È9.

(2) am ÂÃNÉ "V v P Y Å =8 È"' Y>? = >?WB~

µ Hà3 j9.

(3) ì TL F d f§ q "V v

ÂÃÖ¥ f§ 4µz¢{ çÈ9. f§ 4µz¢ åZ

j" f§ 4µz¢¨ Chehbouni +[19] 4µz F~

(, { Ì3 j9.

ì TL& ~rf,å -2FTLÂ(O E/"V æ.`

9. TL 2I Ë(/0`9.

Ar : Archimedes number, ρ_g(ρ_p−ρ_g)gd_p³/µ²[-]

C_D : drag coefficient [-]

d_p : particle diameter [mm]

d_p : mean particle diameter [mm]

d_pt : particle diameter having a terminal velocity that is equal to the superficial velocity [mm]

D_t : column diameter [m]

g : gravitational acceleration [m/s²] G_s : solid circulation rate [kg/m²s]

H_t : column height [m]

P : pressure [kPa]

Re_p : particle Reynolds number, d_pUρ_g/µ [-]

Re_tr : Reynolds number at transition velocity to fast fluidization, d_pU_trρ_g/µ [-]

T : temperature [^oC]

U : superficial gas velocity [m/s]

U_ms : minimum slugging velocity [m/s]

U_s : velocity of the solids [m/s]

U_t : terminal velocity [m/s]

U_tr : transition velocity from turbulent to fast fluidization [m/s]

Table 4. Continued

Authors D_t[m] H_t[m] Particles d_p[µm] ρ_p[kg/m³] Geldart’s group T[^oC] P[kPa] U_tr[m/s] U_tr Determining method^*

Tsukada et al.[13] 0.05 0.4 FCC 46 1780 A A.C. 100

350 700

0.75 0.50 0.41

2 2 2

Chehbouni et al.[18] 0.082 FCC 78 1450 A A.C. A.C. 1.1-1.2

1.2 1-1.1

3, 4, 7 (APT) 3, 4, 7 (DPT) 3, 4, 7 (CP)

0.082 Sand 130 2650 B A.C. A.C. 2.4

2.3 2.0

3, 4, 7 (APT) 3, 4, 7 (DPT) 3, 4, 7 (CP) Chehbouni et al.[19] 0.082

0.200

Sand FCC Sand FCC

130 78 130

78

2650 1450 2650 1450

B A B A

A.C. A.C. 2.20

1.10 3.05 2.24

4, 7 4, 7 4, 7 4, 7

Delebarre et al.[26] 0.2 1.0 Glass bead 68 2490 A A.C. A.C. 0.93 7

Yi et al.[29] 0.035 4.65 KSZ1 59 1820 A A.C. A.C. 1.7 11

Namkung et al.[22] 0.1 5.3 FCC 65

65

1720 1720

A A

A.C. A.C. 1.40

1.44

7 6 Silica sand 125

125

3055 3055

B B

A.C. A.C. 2.40

2.52

7 6 A.C.: ambient conditions, DPT: differential pressure transducer, APT: absolute pressure transducer, CP: capacitance probe

*Symbol listed in Table 1

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39 4 2001 8

∆P : pressure drop [mmH₂O]

∆Z : axial distance [m]

!

ε : average gas holdup [-]

µ : gas viscosity [kg/m-s]

ρ_g : gas density [kg/m³]

ρ_p : apparent particle density [kg/m³]

1. Arnaldos, J. and Casal, J.: Powder Technology, 86, 285(1996).

2. Bi, H. T., Ellis, N., Abba, A. and Grace, J. R.: Chem. Eng. Sci., 55, 4789(2000).

3. Lewis, W. K., Gilliland, E. R. and Bauer, W. C.: Ind. and Eng. Chem., 41, 1104(1949).

4. Yerushalmi, J., Turner, D. H. and Squires, A. M.: Ind. Eng. Chem.

Proc. Des. and Dev., 15, 47(1976).

5. Avidan, A. and Yerushalmi, J.: Powder Technology, 32, 223(1982).

6. Schnitzlein, M. G. and Weinstein, H.: Chem. Eng. Sci., 46, 2605(1988).

7. Yerushalmi, J. and Cankurt, N. T.: Powder Technology, 24, 187(1979).

8. Horio, M., Nishimuro, M. and Ishii, H.: Proc. of the 3rd SCEJ Symp.

on Circulating Fluidized Beds, 54(1989).

9. Bi, H. T., Jiang, P. J. and Fan L. S.: AIChE Meeting, Paper no. 101d, Los Angeles(1991).

10. Jiang, P. J. and Fan, L. S.: AIChE Meeting, Paper #101e, Los Ange- les, CA(1991).

11. Horio, M., Ishii, H. and Nishimuro, M.: Powder Technology, 70, 229 (1992).

12. Adánez, J., de Diego, L. F. and Gayan, P.: Powder Technology, 77, 61(1993).

13. Tsukada, M, Nakanishi, D. and Horio, M.: 4th Int. Conf. on Circu- lating Fluidized Beds preprint volume, 248(1993)

14. Chen, B., Li, Y., Wang, F., Wang, S. and Kwauk, M.: Chem. Metal- lurgy(in Chinese), 4, 20(1980).

15. Li, Y. and Kwauk, M.: “Fluidization,” edited by Grace, J. R. and Matsen, J. M., Plenum Press, New York, 537(1980).

16. Kwauk, M., Wang, N., Li, Y., Chen, B. and Shen, Z.: “Circulating Fluidized Bed Technology,” edited by Basu, P., Pergamon Press, Toronto, 33(1985).

17. Perales, J. F., Coll, T., Llop, M. F., Puigjaner, L., Arnaldos, J. and Cassal, J.: “Circulating Fluidized Bed Technology III,” edited by Basu, P., Horio, M. and Hasatani, M., Pergamon Press, New York, 73(1990).

18. Chehbouni, A., Chaouki, J., Guy, C. and Klvana, D.: Ind. Eng. Chem.

Res., 33, 1889(1994).

19. Chehbouni, A., Chaouki, J., Guy, C. and Klvana, D.: Can. J. of Chem.

Eng., 73, 41(1995).

20. Leu, L. P., Huang, J. W. and Gua, B. B.: Proc. Asian Conf. on Flu- idized Bed and Three-Phase Reactors, Beijing, China, 71(1990).

21. Yang., Y. R., Rong, S. X., Chen, G. T. and Chen, B. C.: Chem. Reac- tion Eng. and Technol., 6, 9(1990).

22. Namkung, W., Kim, S. W. and Kim, S. D.: Chem. Eng. J., 72, 245(1999).

23. Lee, J. S. and Kim, S. D.: HWAHAK KONGHAK, 20, 207(1982).

24. Shin, B. C., Koh, Y. B. and Kim, S. D.: HWAHAK KONGHAK, 22, 253(1984).

25. Han, G. Y., Lee, G. S. and Kim, S. D.: Korean J. Chem. Eng., 2, 141 (1985).

26. Delebarre, A., Bitaud, B. and Regnier, M. C.: Powder Technology, 91, 229(1997).

27. Le Palud, T. and Zenz, F. A.: “Fluidization,” edited by Grace, J. R., Shemilt, L. W. and Bergougnou, M. A., Engineering Foundation, New York, 121(1989).

28. Bi, H. T., Grace, J. R. and Zhu, J. X.: Transactions of the Institution of Chemical Engineers, 73, 154(1995).

29. Yi, C. K., Son, J. E., Jin, G. T., Shun, D. W., Park, J. H., Han, K. H., Jo, S. H. and Lee, S. Y.: “Solid Circulation Technology for the Stable Operation of a Hot Gas Desulfurization Bench-Scale Unit,” Research Report, KIER994613, 17(1999).

30. Lee, G. S. and Kim, S. D.: Powder Technology, 62, 207(1990).

31. Bi, H. T. and Fan, L. S.: AIChE J., 38(2), 297(1992).

32. Choi, J. H., Son, J. E. and Kim, S. D.: J. Chem. Eng. Japan, 22, 597 (1989).

33. Son, J. E., Choi, J. H. and Kim, S. D.: “Fluidization VI,” edited by Grace, J. R., Shemilt, L. W. and Bergougnou, M. A., Engineering Foundation, 113(1989).

34. Merrick, D. and Highley, J.: AIChE Symp. Ser., 70, 366(1974).

35. Lee, J. K., Hu, C. G., Shin, Y. S. and Chun, H. S.: Can. J. Chem.

Eng., 68, 824(1990).

36. Park, S. S., Choi, Y. T., Lee, G. S. and Kim, S. D.: “Circulating Flu- idized Bed Technology,” edited by Basu, P., Horio, M. and Hasatani, M., Pergamon Press, Oxford, 497(1990).

37. Lee, W. J., Cho, Y. J., Kim, J. R. and Kim, S. D.: Proc. 3rd Asian Conf. on Fluidized-Bed and Three-Phase Reactors, 126(1992).

38. Wen, C. Y. and Chen, L. H.: Proc. 6th Int. Conf. on FBC, III, 1115 (1980).

39. Romanova, T. T. et al.: Deposited Doc., Viniti 5129-80(1980).

40. Milne, B. J., Berruti, F., Behie, L. A. and Theo, J. W.: Proc. 4th Int.

Conf. on CFB, 29(1993).

41. Zhang, X., Cao, Y., Ren, Y., Chen, J. and Hong, Y.: Proc. 8th Int.

Conf. on FBC, I, 75(1985).

42. George, S. E. and Grace, J. R.: Can. J. Chem. Eng., 59, 279(1981).

43. Choi, J. H., Choi, K. B., Kim, P., Shun, D. W. and Kim, S. D.: HWA- HAK KONGHAK, 33, 580(1995).

44. Ryu, H. J. and Choi, J. H.: HWAHAK KONGHAK, 35, 173(1995).

45. May, W. G. and Russel, F. R.: paper presented at the North Jersey sec- tion of the A.C.S.(Jan. 25, 1954).

46. Zenz, F. A. and Weil, N. A.: AIChE J., 4, 472(1958).

47. Chan, I. H. and Knowlton, T. M.: “Fluidization,” edited by Kunii, D.

and Toei, R., Engineering Foundation, 283(1984).

48. Knowlton, T. M.: “Fluidization VII,” edited by Potter, O. E. and Nicklin, D. J., 27(1992).

49. Knowlton, T. M., Findlay, J. and Sishtla, C.: Final Report, DOE/MC/

22061-2883, DE90 009699(1990).

50. Li, J., Li, Y. and Kwauk, M.: “Circulating Fluidized Bed Technol- ogy II ,” edited by Basu, P. and Large, J. F., Pergamon Press, Toronto, 75 (1988).

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