• Title, Summary, Keyword: Bubble Column

Search Result 126, Processing Time 0.033 seconds

Comparative Study of Mass Transfer and Bubble Hydrodynamic Parameters in Bubble Column Reactor: Physical Configurations and Operating Conditions

  • Sastaravet, Prajak;Chuenchaem, Chomthisa;Thaphet, Nawaporn;Chawaloesphonsiya, Nattawin;Painmanakul, Pisut
    • Environmental Engineering Research
    • /
    • v.19 no.4
    • /
    • pp.345-354
    • /
    • 2014
  • In this paper, effects of physical configurations and operating conditions on bubble column performance were analyzed in terms of bubble hydrodynamic and mass transfer parameters. Bubble column with 3 different dimensions and 7 gas diffusers (single / multiple orifice and rigid / flexible orifice) were applied. High speed camera and image analysis program were used for analyzing the bubble hydrodynamic parameters. The local liquid-side mass transfer coefficient ($k_L$) was estimated from the volumetric mass transfer coefficient ($k_La$) and the interfacial area (a), which was deduced from the bubble diameter ($D_B$) and the terminal bubble rising velocity ($U_B$). The result showed that the values of kLa and a increased with the superficial gas velocity (Vg) and the size of bubble column. Influences of gas diffuser physical property (orifice size, thickness and orifice number) can be proven on the generated bubble size and the mass transfer performance in bubble column. Concerning the variation of $k_L$ coefficients with bubble size, 3 zones (Zone A, B and C) can be observed. For Zone A and Zone C, a good agreement between the experimental and the predicted $K_L$ coefficients was obtained (average difference of ${\pm}15%$), whereas the inaccuracy result (of ${\pm}40%$) was found in Zone B. To enhance the high $k_La$ coefficient and absorption efficiency in bubble column, it was unnecessary to generate numerous fine bubbles at high superficial gas velocity since it causes high power consumption with the great decrease of $k_L$ coefficients.

Effects of Various Bioreactors on Growth and Ginsenoside Accumulation in Ginseng Adventitious Root Cultures(Panax ginseng C.A. Meyer) (다양한 생물반응기 형태가 인삼(Panax ginseng C.A. Meyer) 부정근의 생장과 Ginsenoside 생산에 미치는 영향)

  • Kim, Yun-Soo;Hahn, Eun-Joo;Paek, Kee-Yoeup
    • Journal of Plant Biotechnology
    • /
    • v.31 no.3
    • /
    • pp.249-253
    • /
    • 2004
  • The type of air lift bioreactor affected the root growth in ginseng adventitious root cultures. Among bioreactors used in this experiment, bulb type bubble bioreactor (BU) was the best to increase root growth (41.92 g dry weight). The kLa value representing the oxygen transfer capacity from medium to explants (6.98 h$^{-1}$ ) in BU with 5 cm bubble column was higher than other bioreactors. On the other hand, cylindric tube bioreactor (CT) without bubble column resulted in minimum root growth (38.55 g dry weight) and kLa value (5.25 h$^{-1}$ ). Furthermore, the root growth (50.30 g dry weight) in BU with 10 cm bubble column more increased than 5 cm bubble column. However, the kLa value do not affected the secondary metabolite such as ginsenosides. These results show that the bubble column in air lift bioreactor increase kLa value and increased kLa value stimulate the growth of ginseng adventitious roots.

The Growth of Transgenic Tobacco′s Suspension Culture and the Production of β-Glucuronidase in Bubble Column Bioreactor (Bubble column bioreactor에서 형질전환된 담배세포의 성장양상 및 β-Glucuronidase의 생산)

  • 김석우;이동근;현진원;이상현;하종명;하배진;이재화
    • Journal of Life Science
    • /
    • v.12 no.5
    • /
    • pp.577-583
    • /
    • 2002
  • The growth kinetics and the production of $\beta$-glucuronidase from transgenic tobacco's suspension culture was investigated in the flask culture and a 2.5 L bubble column reactor. The growth of bubble column reactor was similar to that of flask culture. However, in the bubble column reactor, the production of $\beta$ -glucuronidase reached 2850 U/mg (85-fold higher than that of flask culture). In both case, the production level of $\beta$ -glucuronidase was fluctuated, which was resulted from periodical degradation of the protein. Sucrose is important component in plant culture medium. Twice addition of sucrose in bubble column reactor could not improve cell growth, since other components in a medium were already depleted. However, the addition of sugar decreased cell size, which facilitated the operation of bioreactor. The production of $\beta$ -glucuronidase was continuously increased, however final concentration of $\beta$ -glucuronidase was similar to that without sucrose addition.

Holdup Characteristics of Small Bubbles in a Viscous Slurry Bubble Column (점성슬러리 기포탑에서 작은 기포의 체류량 특성)

  • Jin, Hae-Ryong;Song, Yang-Ho;Kang, Yong;Jung, Heon;Lee, Ho-Tae
    • Korean Chemical Engineering Research
    • /
    • v.49 no.1
    • /
    • pp.83-88
    • /
    • 2011
  • Holdup characteristics of small bubbles were investigated in a viscous slurry bubble column. The phase holdup of small bubbles was obtained from the knowledge of total bubble(gas) holdup and large bubble holdup, which were measured by mean of static pressure drop method and dual resistivity probe method, respectively. Effects of gas velocity, viscosity of continuous liquid phase and solid fraction in the slurry phase on the small bubble holdup as well as holdups of total bubble(gas) and large bubble in a viscous slurry bubble column. The small bubble holdup increased with increasing gas velocity but decreased with increasing liquid viscosity or solid fraction in the slurry phase. In addition the fraction of small bubble in the total bubble(gas) holdup increased with increasing gas velocity but decreased with increasing liquid viscosity or solid fraction in the slurry phase. It was revealed that the rising velocity of large bubble did not related to the holdup of small bubble in a viscous slurry bubble column.

Bubble-column Photobioreactor에서의 Astaxanthin 유도배양의 연구

  • Choe, Su-Rim;Seo, In-Su;Lee, Cheol-Gyun
    • 한국생물공학회:학술대회논문집
    • /
    • /
    • pp.220-223
    • /
    • 2002
  • This study investigated a lab-scale inducing method for efficient astaxanthin accumulation. As a model system. Haematococcus pluvialis was cultivated in 2 liter bubble-column photobioreactors. The astaxanthin - inducing results using high light irradiation were compared with that of the control experiment under standard irradiation (40 ${\mu}E/m^2/s$). After the late linear growth phase (> 20 days). high light energy (230 ${\mu}E/m^2/s$) was supplied to the culture broth for astaxanthin induction. As a result. the dr γ cell weight and the astaxanthin productivity were increased up to 68% and 215%, respectively. higher than those of the control experiment. This result indicates that bubble-column type photobioreactor is a good candidate for mass cultivation of H. pluvialis and high light irradiation is an efficient induction method for astaxanthin accumulation in lab-scale bubble-column photobioreactors.

  • PDF

Design Parameters Estimations for Bubble Column Reactors to Remove Toxic Gases (독성가스 제거용 기포탑 반응기의 설계기법)

  • Oh, Junghwan;Hong, Min Sun
    • Korean Journal of Hazardous Materials
    • /
    • v.6 no.2
    • /
    • pp.99-108
    • /
    • 2018
  • Gas-liquid bubble column reactors are extensively used in industrial processes. A detailed knowledge of bubble size distribution is needed for determining the mass transfer in gas-liquid film. Experimental data on bubble size distribution and liquid-side mass transfer coefficient($k_L$) were used to calculate the estimated time to saturation in bubble column reactor. Also, the gas flux was evaluated to the liquid-side mass transfer coefficient($k_L$) and solubility data for hydrogen sulfide($H_2S$) and chlorine($Cl_2$) absorption into water. Simulation results show that $H_2S$ absorption time to 50 % of saturation concentrations are 611 sec and 1,329 sec when bubble diameters are 0.5 mm and 4.5 mm, while absorbing 1 % $H_2S$ gas. In case of $Cl_2$, absorption time range 657 to 1,400 sec when bubble size range 0.5 mm to 4.5 mm, while absorbing 1 % $Cl_2$ gas. Calculated simulation results can be used in the design of emergency relief bubble reactors.

Effect of Aspergillus niger Pellets on Citric Acid Production in a Bubble Column Bioreactor

  • Kim, Seung-Hwan;Yoo, Young-Je;Kim, Eui-Yong;Kim, Min-Hong
    • Journal of Microbiology and Biotechnology
    • /
    • v.5 no.3
    • /
    • pp.172-176
    • /
    • 1995
  • Citrate is mainly produced from fungi and oxygen transfer has been known as one of the important factors in citric acid production. A bubble column bioreactor was used for citrate production after pellet was initially made using a stirred bioreactor for the inoculation. The relationship between the pellet size of Aspergillus niger and the oxygen transfer was elucidated by considering morphological characteristics of the pellet. The pellet size was determined by adjusting the impeller speed in the stirred bioreactor and the optimum diameter of the pellet was observed to be 2.2 mm under the experimental conditions. Pellet was maintained quite stable in the bubble column bioreactor and production of citric acid was significantly improved by maintaining optimal pellet conditions in the bubble column bioreactor.

  • PDF

The Effect of Partitioning Porous Plate on Bubble Behavior and Gas Hold-up in a Bench Scale (0.36 m × 22 m) Trayed Bubble Column (벤치스케일(0.36 m × 22 m) 다단형 기포탑에서 다공판이 기포의 거동 및 기체 체류량에 미치는 영향)

  • Yang, Jung Hoon;Hur, Young Gul;Lee, Ho-Tae;Yang, Jung-Il;Kim, Hak-Joo;Chun, Dong Hyun;Park, Ji Chan;Jung, Heon
    • Korean Chemical Engineering Research
    • /
    • v.50 no.3
    • /
    • pp.505-510
    • /
    • 2012
  • The gas hold-up has a strong relationship with the size distribution and rising velocities of bubbles in a bubble column. Therefore, many previous researchers have studied on the hydrodynamics focusing on the bubble size variation in bubble column. In this study, the bubble behavior was influenced by partitioning porous plates installed at a certain height in a trayed bubble column. The gas hold-up was increased in non-sparging region (H/D > 5) as well as sparging region. We identified the effect of the partitioning porous plate using three trayed bubble columns with different reactor geometries. Furthermore, the bubble break-up frequency and size distribution were observed before and after individual bubbles penetrated through the plate. The arrangement of the plates was also investigated using a 0.15-m-in-diameter bubble column. Based on the result, we applied this design concept to a 0.36-m-in-diameter, 22 m tall trayed bubble column and identified the effect of the partitioning porous plate on the gas hold-up increase.

Size Verification of Small and Large Bubbles in a Bubble Column (기포탑에서 작은기포와 큰기포의 크기 구별)

  • Seo, Myung Jae;Jin, Hae-Ryong;Lim, Dae Ho;Lim, Ho;Kang, Yong;Jun, Ki-Won
    • Korean Chemical Engineering Research
    • /
    • v.50 no.2
    • /
    • pp.304-309
    • /
    • 2012
  • Size verification of small and large bubbles in a bubble column was investigated by employing the dynamic gas disengagement (DGD) method and dual electrical resistivity probe (DRP) method, simultancously. The holdups of large and small bubbles in the bubble column in a given operating condition were obtained by means of the DGD method by measuring the pressure drop variation in the column with a variation of time after stopping the gas input into the column. The size and frequency of bubbles were measured by the DRP method in the same operating condition, from which the bubble holdup of each range of size was obtained. The verification of size in determining the large or small bubbles was decided by comparing the holdups of large or small bubbles measured by the DGD method with that measured by the DRP method. Filtered compressed air and tap water were used as a gas and a continuous liquid medium. The diameter and height of the bubble column were 0.102 m and 1.5 m, respectively. The demarcation size between the large and the small bubbles in the bubble column was 4.0~5.0 mm; the demarcation size was about 5.0 mm when the gas velocity was in the relatively low range, but about 4.0 mm when the gas velocity was in the relatively high range, within this experimental conditions.

Axial and Radial Distributions of Bubble Holdup in a Slurry Bubble Column with Pilot Plant Scale (파일럿규모 슬러리 기포탑에서 기포체류량의 축방향, 반경방향 분포)

  • Lim, Dae-Ho;Jang, Ji-Hwa;Kang, Yong;Jun, Ki-Won
    • Korean Chemical Engineering Research
    • /
    • v.49 no.2
    • /
    • pp.200-205
    • /
    • 2011
  • Axial and radial distributions of bubble holdup were investigated in a slurry bubble column with pilot plant scale(D=1.0 m). Effects of gas velocity, surface tension of continuous liquid medium and solid fraction in the slurry phase on the axial and radial distributions of bubble holdup were examined. The bubble holdup decreased with increasing radial dimensionless distance from the center of the column, while it increased with increasing dimensionless distance in the axial direction from the distributor, in all the cases studied. The radial non-uniformity of bubble holdup increased with increasing gas velocity but decreasing surface tension of liquid medium, while it was not dependent upon the solid fraction in the slurry phase. The axial non-uniformity of bubble holdup increased with increasing gas velocity, but it does not change considerably with variations of liquid surface tension or solid fraction in the slurry phase . The axial and radial distributions of bubble holdup were well correlated in terms of operating variables within this experimental conditions.