风城超稠油预处理工艺的改进

摘要

When pretreating mixed Fengcheng super heavy crude oil (containing 60%-70% Fengcheng super heavy crude) , overload of electric current often happened at the electric desalting device of delayed coking unit. It was found that processing crude with high water content from the bottom of crude tank was the main reason. In order to keep electric desalting unit running safely and smoothly, some improvements were conducted, such as increase the dewater frequency and temperature of crude tank, mixed processing the high water bottom crude in small amount with conventional crude, shifting the demulsifier injection spot forward, decrease the mixing force of mixing valve, as well as the transformer voltage. Since then the water and salt contents of purified crude dropped to less than 0. 5% and 7. 5 mgNaCl/L, respectively. Some other measures to further reduce the water and salt contents of Fengcheng crude for meeting the required targets (less than 0. 3% and 3.0 mgNaCl/L, respectively) were proposed as well.%风城超稠油混合油(含60％～70％风城超稠油)进入焦化单元电脱盐装置时存在电流经常超限的问题,通过分析发现原料罐底水含量偏高是主要原因.通过采取增加原料罐脱水频率、提高原料罐温度、罐底油带炼、破乳剂注入点前移、降低混合阀混合强度和变压器电压的措施,使电脱盐装置能够安全平稳运行,净化油中水质量分数控制在0.5％以下,盐(NaCl)质量浓度控制在7.5 mg/L以下.为了进一步降低净化油中水、盐含量,使其达到装置指标要求[水质量分数不大于0.3％,盐(NaCl)质量浓度不大于3.0 mg/L],提出了进一步改进的措施.