| 摘要 |
1417486 Aerating and circulating liquids IMPERIAL CHEMICAL INDUSTRIES Ltd 3 May 1974 [16 May 1973] 23330/73 Addition to 1353008 Heading B1C [Also in Divisions Cl and C6] Chemical and biochemical reactions involving contacting a liquid and gas, such as the production of aqueous solutions of copper sulphate from copper sulphide-containing mineral ores suspended in aerated aqueous medium, the production of single cell protein by growing micro-organisms upon hydrocarbon or methanolic substrates, or the microbiological production of citric acid, amino acids e.g. lysine, glutamic acid and methionine, enzymes e.g. glucose isomerase and antibiotics e.g. penicillin, are carried out in circulatory apparatus consisting essentially of a riser 1, Fig. 1, a downcomer 5, gas injection spargers 11 and 13, bubble break up devices 16 in the riser and heat exchanger 17. Feed medium containing the elements essential for fermentation enters through line 14 and culture is removed through line 15. Gas bubbles escape from the free surface A-A of the liquid and are vented through line 12. This apparatus and its method of use are broadly described and claimed in the parent Specification 1353008. According to the present Specification, the apparatus is to be at least 20 metres in height e.g. between 40 and 60 metres, the total useful cross-sectional area of the riser is to be greater than, viz. between three and eight times, that of the downcomer, and the circulation of the liquid around the system is to be effected by injecting a gas thereinto in an amount sufficient to impart a mean velocity of at least 15 cms/sec to the liquid in the riser. Between 10% and 100% of the total volume of gas injected into the system may be injected into the liquid in the downcomer at 1 to 5 levels. Typically, the hourly rate of transfer of oxygen into the liquid culture is at least 2 kg. O 2 per cubic metre, and the mean velocity of liquid is between 20 and 80 cm/sec in the riser and between 200 and 500 cms/sec in the downcomer. The apparatus may have 3 to 8 risers and a single downcomer, the cross-sectional area of each riser being the same as that of the downcomer. Figs. 2 to 7 (not shown) depict other constructions of apparatus. |
