On-line leak detection method for lining of urea synthetic tower

Abstract

The invention discloses an on-line leak-detecting means for the liner of a urea synthetic tower, and is characterized in that the invention comprises the following steps: 1. supporting gas with constant pressure is fed into the loose lining gap layer and the leak detection channel between the stainless steel liner and the encloser of the urea synthetic tower; 2. the supporting gas flowing out of a leakage-detection hole is admitted into a washing tank, and the supporting gas is absorbed with supporting gas cleaning solvent fed continuously; 3. the conductivity of the supporting gas cleaning solvent is measured with a measuring device, and is transmitted to the DCS Operating System, and whether the lining layer of the urea synthetic tower leaks is determined through analyzing the change trend of the preset values relative to the warning message and the detected data. The on-line leak-detecting means provided by the invention has the advantages of high response speed, high detection accuracy, high reliability and saving investment.

Description

technical field [0001] The invention relates to an online leak detection method for the lining of a urea synthesis tower. Background technique [0002] At present, the main urea production process in my country is carbon dioxide stripping method, ammonia stripping method, aqueous solution full circulation method, and the core equipment of the improved C method. Carbon steel shell composition. Due to the limitation of equipment manufacturing technology (mainly welding residual stress), there is always a possibility of leakage in the urea synthesis tower in the environment of high temperature, high pressure and strong corrosion reaction in the tower. Once the stainless steel lining leaks, the high temperature, high pressure and strong corrosive The steel shell will be severely corroded, which will eventually lead to a vicious accident. For this reason, the carbon steel shell outside the stainless steel lining of the urea synthesis tower is designed with leak detection holes, ...

AI Technical Summary

Problems solved by technology

The synthesis tower of a domestic urea plant adopts an ammonia infrared analysis online leak detection system. The defect of this leak detection technology is that it takes a long time to respond to the leakage medium, and there is no regulation on the use pressure of the carrier gas, whether it is in line with the safety of the urea synthesis tower. The operating procedures need to be verified; the synthesis tower of another urea plant adopts the gas-covered spot check online leak detection technology without leak detection medium. Causes corrosion and forms explosive gas mixtures

In addition, these systems still have some common disadvantages: ①The design is relatively complicated; ②The core instrumentation equipment used in monitoring is not mature enough, and its reliability needs to be verified; ③The main equipment used is expensive and the project investment is high

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