Abstract:

Quench system is a unit of ethylene plant with complex operating conditions and many restricting factors. In this paper, the characteristics of the quench technology were described, and it was emphasized that the composition of cracking gas was very important to the setting of quench process. According to the different effects of raw materials on quench process, the quench process can be divided into three kinds, which were heavy liquid raw material, light liquid raw material and gas raw material (ethane, propane). In this paper, a typical process flow diagram was provided for the quench technology of liquid raw materials, and the heat removal cycle of the quench system of light and heavy liquids was compared and analyzed. The optimization principle of key technical parameters of the quench system was put forward, especially the characteristics and determination methods of the quench technology of light liquid in heat distribution and bottom temperature control of quench oil tower were explained. The quench technology of gas raw material had outstanding characteristics. This paper proposed three kinds of decoking technologies for step by step decoke and purification, and described the combined purification technology of “gas flotating + coalescence” in detail. In this paper, the design and optimization method of quench system were provided, and the application and effect of quench technology of light liquid raw material and ethane gas were also described.

Key words: quench, cracking gas, reflux, purification of quenching water, gas floating, coalescence

摘要：

急冷系统是乙烯装置中操作条件复杂、制约因素很多的单元。本文对急冷技术的特点进行了说明，强调裂解气组成的轻重对急冷流程设置非常关键。根据原料对急冷流程的影响不同，急冷流程可分为重质液体原料、轻质液体原料、气体原料（乙烷、丙烷）三种。本文针对液体原料急冷技术，提供了典型工艺流程图，并对轻重液体的急冷系统撤热循环进行了对比分析，提出了急冷系统的关键技术参数优化原则，特别说明了轻质液体急冷技术在热量分配、釜温控制的特点和确定方法。气体原料急冷技术特点突出，本文提出逐级除焦、分步净化的三种除焦技术，并对“气浮+聚结”组合净化技术进行了详细说明。本文在提供急冷系统设计和优化方法的同时，也阐述了轻质裂解原料急冷技术和乙烷裂解急冷技术的应用情况和效果。

关键词: 急冷, 裂解气, 回流量, 工艺水净化, 气浮, 聚结