Produced-Water Treatment Technology— A Study of Oil/Water Separation in Gravity-Type Crossflow Pack Separators for Qualitative Separation

Abstract

Summary To handle ever-increasing oily water volumes and to improve water quality discharge, separation equipment should be developed to meet industry demand and match environmental regulations. However, special constraints such as size, simplicity of operation, variable fluids, different operating conditions, and economics warrant special emphasis. Therefore, the study of traditional gravity-type oil/water separation equipment is essential to enhance the separation process and maximize its effectiveness. This will become increasingly important as environmental regulations become more stringent in the future. This paper, trying to meet this target, presents a modified design for the standard crossflow pack (CFP) separator. The new added development to the design of the separator incorporates a mechanism whose function will be forwarded to provide a shaking motion to its stationary plate pack. This mode of operation has the potential to improve oil/water separation, minimize the plugging tendency of the plates, and consequently maximize the effectiveness of the crossflow pack separator. The obtained results revealed that the effectiveness of the cross-flow pack separator had been increased because of the shaking of its plate pack, and it reached its peak value at the flow Reynolds number (based on the hydraulic diameter as the characteristic length) equivalent to 1,830. On average, the CFP separator removed all oil particles greater than 30 ßm for streams whose oil-in-water concentration was greater than 150 ppm. Therefore, it can be demonstrated that providing a shaking motion to the traditional CFP separator has an appreciable potential to improve oil/water separation. Continuing research is encouraged, to ensure the establishment and achievment of proper scientific criteria for the CFP separator.