| 摘要 |
<p>1496143 Purifying waste gases GORDON JOHNSON-STEPHENS (HOLDINGS) Ltd 4 June 1975 [6 June 1974] 25197/74 Heading A5G [Also in Division C1] Off-gases resulting from processing animal waste products in a cooker are washed first with an alkali, e.g. aqueous caustic soda and then with an oxidising agent, e.g. aqueous chlorine or hypochlorite solution, to remove malodorous constituents such as H 2 S, NH 3 , SO 2 and CO. In one embodiment, skins, bones, feathers, blood &c is cooked in 4, any carryover material in off-gas line 5 is being drained from pot 6 into contact tank 8. The offgases in line 5 are cooled at 9 and 17 and then passed into scrubbing tower 20 countercurrent to aqueous caustic soda from 21. The caustic soda via line 23 and finally discharged via line 32 to tank 8. The washed gases are then fed into gas-scrubber 40, countercurrently against aqueous chlorine and released to atmosphere via stack 42. Used chlorine solution is discharged via 44 to tank 8. Aqueous chlorine, injected into tank 8 from 60, together with caustic soda from line 32 desulphurizes the condensed effluent from 15 and the carry-over from 7. To cater for the inrush of air carrying off malodorous gases when cooker 4 is taken out of operation and opened, supplementary chlorination unit 80 is provided comprising a tower 85 through which lightly polluted air passes countercurrent to aqueous chlorine.</p> |
