Treating liquids contaminated with oils, esp. emulsions of oils - in which carry-over of oil in the vapour evolved in evaporative oil-water separator is prevented by using centrifugal separator

摘要

In the treatment of liqs. contaminated with oils by evapn., the parameters of the evapn. process (stages I to IV) are chosen so as to limit the oil concn. in the vapour evolved, principally by keeping the oil concn. in the liq. being treated below a max. allowed level. The liq. is then taken to a separator in which oil is removed from it, and the remaining liq. is the further evaporated. The proposed max. allowed oil concn. is 20%. USE/ADVANTAGE - Used in the treatment of oil-contaminated liqs., such as oily waste water which must have the oil removed before it can be taken to a waste water treatment plant. The essence of the invention is that the oil is removed from the water and concentrated by evaporation to the required 98% oil content, without the need to evaporate a liq. with a high oil content. This is an advantage since the evapn. of liqs. with high oil content inevitably involves the prodn. of an undesirable level of oil carry-over in the vapour evolved during evapn.. This is avoided by using a separator to remove oil from the water once a certain level of oil concn. has been reached in the evaporation equipment.