Study On Oil Removal Principle And Treatment Device For Long-Distance Pipeline Pressure Test And Emptying Oily Sewage

Oily sewage of long-distance pipeline is mainly from the process of pressure test and emptying. The oily sewage is formed by mixing the residue oil in the pipeline and oil pump with water. Oily sewage discharged can cause environment pollution and waste of resources. For the characteristics of discontinuities, large density difference, lower oil content and less suspension in fuel depot and pipeline system, the oily sewage treatment apparatus based on the coalescence separation technology was developed in this thesis. Based on experiment and numerical simulation method, the sewage treatment apparatus was studied, as follows:(1) Coalescence mechanism was discussed, the motion equation of the liquid droplet in the fluid was derived, and the influence of main factors on the separation efficiency of Oil/Water Separation was analyzed.(2) This sewage treatment apparatus was composed of two canisters. Coalescence filter was taken as filler. Otherwise, a data acquisition system was designed for real-time data acquisition in sewage treatment process.(3) Numerical analysis of internal flow field of the apparatus was simulated by CFD software. The effects of different inlet structure, treatment capacity, temperatures, pipe diameters and other parameters on the internal flow field of sewage treatment apparatus was studied.(4) Experiments were taken to study the separation effect of the sewage treatment apparatus, including filter mechanical performance and filter separation performance. In the filter mechanical properties experiment, the results showed that the filter fiber material was possessed of organic solvent resistance, crushing resistance and heat resistance. The sewage treatment apparatus was used on the filter separation experiment, the separation performance of the filter under different flow rate, oil content and oil viscosity was studied. By analyzing the pressure fluctuation and the oil content in the experiment with post-processing software, the impact mechanism of oil content, flow rate and oil viscosity to the sewage treatment apparatus oil removal performance was discussed. The results showed that outlet oil content tended to increase with the rise of the flow rate and inlet oil content; and the oily sewage apparatus performed better on high viscosity oily sewage than low viscosity oily sewage.