MDI装置的仪表选型和自动化方案

Instrument Selection and Automated System Design for A MDI Plant

MDI装置工艺物料具有高粘稠、易聚合特性,反应设备真空度高,含有氯化物杂质,遇水极易反应生成尿素,堵塞管路,因此在仪表选型方面存在特殊要求。工艺安全方面:一是该装置涉及到的氯苯和氨为国家重点监管的危险化学品,需要监测可能的泄漏并报警;二是按照HAZOP的要求设置安全仪表系统;三是紧急切断阀的设置。本文主要探讨MDI装置的自动化仪表选型方案、安全设施和措施,为今后同类装置的工程设计提供参考。

The process material of the MDI plant is high viscosity,easy polymerization and high vacuum in the distillation column,containing chloride impurities,easily react with water to generate urea,such that blocking pipes,so there are special requirements in instrument selecting.Regarding to the process safety,firstly,the chlorobenzene and ammonia are hazardous chemicals supervised by authorities,its potential leakage shall be monitored and alarm to personal;Second,a safety instruments shall be used according to the HAZOP analysis;Third,emergency shut-off valves shall be required by GB Code.This document describes the instrument selection,safety facilities and measures,and provide some criteria to the engineering of similar plant.