PROCESS AND DEVICE FOR SCRUBBING WASTE GASES CONTAINING ETHYLENE OXIDE

摘要

The invention concerns a process and device for scrubbing waste gases from a desorption device of a steriliser in which articles requiring sterilisation are exposed to ethylene oxide gas to kill microbes. In the desorption device (1) the sterilised articles are exposed for at least forty eight hours to an air stream in a closed air circulation (1-44-5-6-8-7-9-60-1) which takes up the desorbent ethylene oxide and draws the air/ethylene oxide gas mixture into a scrubber (8) containing a scrubbing liquid consisting of 1-6 % sulphuric acid, thereby creating a large phase boundary surface. The ethylene oxide passes into solution in the scrubbing liquid as ethylene glycol and the air stream is then fed back via a filter (7) into the desorption device (1). The mean ethylene oxide gas concentration is constantly lowered by scrubbing inside the desorption device (1) sufficiently to ensure that the ethylene oxide concentration in the supply air stream is less than the ethylene oxide concentration at a given instant inside the desorption device. The air circulation is then interrupted and the air stream with very low ethylene oxide residues is discharged from the desorption device (1) to the outside. The scrubber is either a tower packing- or scrubbing column (8) through which a circulation (8-10-11-12-13-16-19) of the scrubbing fluid is maintained.