Effect of liquid volume in the gas-separator on the hydrodynamics of airlift reactors

✍ Scribed by Waheed A Al-Masry

• Publisher: Wiley (John Wiley & Sons)
• Year: 1999
• Tongue: English
• Weight: 101 KB
• Volume: 74
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/(sici)1097-4660(199910)74:10<931::aid-jctb127>3.0.co;2-z

✦ Synopsis

Gas hold-up and liquid circulation velocity measurements were made using a 167 dm 3 external loop airlift reactor. The gas-separator was of the open channel con®guration. The reactor height was 2.5 m with riser and downcomer diameters of 0.19 m and 0.14 m respectively. The systems investigated were Newtonian air±water and air±glycerol with the super®cial air velocity varying between 0.02 and 0.12 m s À1 . The ratio of the liquid volume in the gas-separator to the liquid volume in the reactor (volume-ratio) was varied from 0.0% to 37%, to ®nd its minimum critical value for optimum operation of the airlift reactor. For the air±water system, discernible effects of the volumeratio on riser and, downcomer gas hold-ups and liquid circulation velocity were observed at volume ratios 7%. Beyond this value, the volume-ratio had no effect. For a viscous and foaming air±glycerol system the critical volume-ratio was increased to 19%. New and simple correlations for predicting gas hold-up in the riser, gas hold-up in the downcomer, and liquid circulation velocity were developed with reasonable accuracy.