화학공학소재연구정보센터
HWAHAK KONGHAK, Vol.30, No.6, 641-648, December, 1992
크기가 다른 두 입자계의 최소유동화속도 결정 및 유동화 특성
Minimum Fluidization Velocity and Fluidization Characteristics of Binary Particle System
초록
내경이 0.109m인 기-고유동층에서 큰 입자(0.175mm)로 이루어진 계에 크기가 작은 입자(0.359mm, 0.194mm)의 분율을 변화시킴에 따라 나타나는 층분리 현상을 차압전달기로 측정하여 압력요동의 평균압력과 표준편차를 이용하여 분석하였다. 크기가 작은 입자의 분율에 따른 최소유동화속도 변화를 규명하였고, 또한 층내에서 일어나는 기포의 운동과 입자혼합을 표준편차로서 해석하였다. 실험결과 균일입자로 이루어진 계에서만 적용되었던 압력요동의 표준편차와 유속과의 관계로부터 최소유동화속도를 결정하는 방법은 크기가 다른 두 입자계까지 적용될 수 있음을 알 수 있었으며, 입자크기 차이에 의한 층분리 현상을 압력요동으로 예측할 수 있다.
Segregation phenomena occurred from variations of fine particle fractions(0.359mm, 0.194mm) in a 0.109m ID fluidized bed of coarse particle(0.715mm) were measured by a differential pressure transdu-cer and were analyzed by the standard deviation and mean pressure of pressure fluctuation. The variations of minimum fluidizatiion velocity according to fine particle fractions were investigated and the fluidized bed behaviors such as bubble motion and particle mixing were interpreted by the standard deviation. The method for determination of a minimum fluidization velocity from the linear relationship between standard deviation and air velocity which has been applied only for the uniform sized particle system could also be applied in the binary syste. segregation phenomena occurred by the difference of particle size could also be predic-ted by the pressure fluctuations.
  1. Fan LT, Ho TC, Hiraoka S, Walawender WP, AIChE J., 27, 388 (1981) 
  2. Fan LT, Ho TC, Walawender WP, AIChE J., 29, 33 (1983) 
  3. Lirag RC, Littman H, AIChE Symp. Ser., 67, 11 (1971)
  4. Verloop J, Heertjes PM, Chem. Eng. Sci., 29, 1035 (1974) 
  5. Puncochar M, Drahos J, Cermak J, Selucky K, Chem. Eng. Commun., 35, 81 (1985)
  6. Park D, Lee JK, Fuel, 68, 1180 (1989) 
  7. Brunner CR, Environ. Prog., 8, 163 (1989)
  8. Carsky M, Pata J, Vesely V, Hartman M, Powder Technol., 51, 237 (1987) 
  9. Geklart D, Powder Technol., 7, 285 (1973) 
  10. Darton RC, LaNanze RD, Davidson JF, Harrison D, Trans. Inst. Chem. Eng., 55, 274 (1977)
  11. Cheremisinoff NP, "Encyclopedia of Fluid Mechanics," 4, Gulf Publ., Huston, 853 (1986)
  12. Drahos J, Cermak J, Schugerl K, Chem. Eng. Commun., 65, 4 (1988)
  13. Hong SC, Jo BR, Doh DS, Choi CS, Powder Technol., 60, 215 (1990) 
  14. Peeler JPK, Huang JR, Chem. Eng. Sci., 44, 1113 (1989) 
  15. Kumar A, SenGupta P, Ind. J. Technol., 12, 225 (1974)
  16. Thonglimp V, Docteur-ingenieur Thesis, Institut National Polytechnique, Toulouse (1981)
  17. Goosens WRA, Dumont GL, Spaepen GL, Chem. Eng. Prog., 67, 38 (1971)
  18. Chiba S, Chiba T, Nienow AW, Kobayashi H, Powder Technol., 22, 255 (1979) 
  19. Cheung L, Nienow AW, Rowe PN, Chem. Eng. Sci., 29, 1301 (1974) 
  20. Beeckmans JM, Stahl B, Powder Technol., 53, 31 (1987) 
  21. Donsi G, Ferrari G, Formisani B, Powder Technol., 55, 153 (1988) 
  22. Nienow AW, Rowe PN, Chiba T, AIChE Symp. Ser., 74, 45 (1978)