| 摘要 |
The method of purifying waste gases from viscose plants claimed in the parent Specification wherein gases consisting of air containing less than 0.1 per cent. hydrogen sulphide are continuously contacted with ferric hydroxide to form non-poisonous, non-malodorous gas, is modified in that the hydrogen sulphide content of the waste air is increased up to a maximum of 0.25 per cent. by adding gas containing hyrogen sulphide obtained in known manner from the sodium sulphate occurring in working up the spinning bath, by reduction of the sulphate, in a furnace with carbon and calcium carbonate, to sulphide and liberation of hydrogen sulphide therefrom by flue gases occurring in the viscose plant, and containing about 12 per cent. carbon dioxide, with nitrogen, and some oxygen.ALSO:The method of purifying waste gases from viscose plants claimed in the parent Specification, wherein gases consisting of air containing less than 0.1 per cent. hydrogen sulphide are continuously contacted with ferric hydroxide to form non-poisonous, non-malodorous gas is modified in that the hydrogen sulphide content of the waste air is increased up to a maximum of 0.25 per cent. by adding gas containing hydrogen sulphide obtained in known manner from the sodium sulphate occurring in working up the spinning bath, by reduction of the sulphate, in a furnace with carbon and calcium carbonate, to sulphide and liberation of hydrogen sulphide therefrom by flue gases occurring in the viscose plant and containing about 12 per cent. carbon dioxide, with nitrogen and some oxygen. |
