Abstract: A sulphur-burning and gaseous products absorption system incorporating control means to establish generation of sulphur dioxide at a rate which is compatible with the capacity of absorption means for absorption of the gases by water, together with controls which make the system fail-safe even when unattended. In order to provide an absorption efficiency compatible with clean air standards, a unique absorption tower is provided, together with pre-cooling means further to improve the absorption tower efficiency. Further, the control efficiency and the purity of the product are improved by ebullition control. A unique joint is provided for sealing the sulphur-burning tower against undesirable leakage which also enables this tower readily to be disassembled for maintenance and repair.