Viscous oil wastewater pretreatment and evaporation desalting system and method

Abstract

The invention relates to a viscous oil wastewater pretreatment and evaporation desalting system and method. A two-stage chemical reaction settling pretreatment system is arranged before an evaporator to effectively remove silicon dioxide and hardness in viscous oil wastewater, a high-temperature scale inhibitor is matched to prevent the heat transfer surface of the evaporator from scaling, so that the evaporator can stably operate for a long time; and concentrated water discharged by the evaporator is naturally evaporated by an evaporation pond to implement zero wastewater discharge of the process system. An evaporation technique is adopted to fully utilize heat energy in the high-temperature viscous oil wastewater, so that the salt content and organic matter content in the condensation water generated by the falling film evaporator are obviously lowered; and the condensation water can be used as station boiler make-up water after being subjected to subsequent organic matter removal and deep desalting treatment. Besides, the two-stage chemical reaction is adopted to remove the silicon dioxide and hardness in the viscous oil wastewater, and the scale inhibitor is combined to prevent the heat transfer surface of the evaporator from scaling, so that the salt content in the condensation water of the evaporator is low, thereby achieving the goal of pre-desalting viscous oil wastewater.

Description

technical field [0001] The invention belongs to the technical field of industrial wastewater treatment and resource recycling, and in particular relates to a heavy oil wastewater pretreatment and evaporation desalination system and method. Background technique [0002] my country is rich in heavy oil resources, mainly distributed in Shengli, Liaohe, Henan, Xinjiang and other oil fields. Due to the high viscosity and poor fluidity of heavy oil, it is necessary to use a large amount of high-pressure, high-dryness steam to heat the oil layer in the process of heavy oil production, so as to improve its fluidity and make it easy to produce. During the thermal recovery of heavy oil using steam, a large amount of high-temperature, high-salt, high-silicon, and high-organic heavy oil waste water needs to be disposed of. At present, the conventional technology is to degrease and soften the heavy oil wastewater to meet the "Steam Injection Boiler Feed Water Quality Index" in the "Code...

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Problems solved by technology

Due to the complex water quality of heavy oil wastewater, high temperature, organic matter, salt content, etc., and strong scaling tendency, it is difficult to completely desaltize it, and no successful engineering case reports have been seen.

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