A vertical cylindrical settler-separator is to be designed for separating a mixture flowing at 20m3/hr and containing equal volumes of a light petroleum liquid (B=875kg/m3) and a dilute solution of wash water (A=1050kg/m3). Laboratory experiments indicate a settling time of 15 minutes is needed to adequately separate the two phases. For design purposes use a 25 minute settling time and calculate the size of the vessel needed, and the height ZA2) of the heavy liquid overflow. Assume that the ends of the vessel are approximately flat, that the vessel diameter equals its height, and that one-third of the volume is vapour space (the vapour space above the liquid is vented to the atmosphere). Also, assume ZA!=ZB