Water flushing process after boiler chemical cleaning

Abstract

The invention discloses a water flushing process after boiler chemical cleaning. The process method comprises the following steps that firstly, cleaning waste liquid is discharged by adopting a negative pressure discharge mode until gage pressure of a waste liquid discharge pipeline is reduced to about 0.05-0.15 MPa, at the moment, a vacuum environment close to one atmospheric pressure is formed inside a cleaning system, and then a cleaning pump is started for water washing until the system is cleaned to be qualified. By adopting the novel process method, air can be prevented from entering theinterior of the cleaning system, so that the problem that the air enters the cleaning system when positive pressure discharging is conducted, and secondary rust is generated due to oxygen in the airoxidizes the surface of a washed metal is effectively avoided; and the negative pressure flushing process method does not need a nitrogen filling system in a nitrogen pressing and discharge flushing method, so that the labor amount of workers is reduced, the cost for installing a temporary system and purchasing nitrogen is saved, and the economic benefits are obvious; and compared with a conventional flushing method, the negative pressure discharge flushing method is good in operability and economical efficiency.

Description

Technical field [0001] The invention belongs to the technical field of chemical cleaning equipment or devices for industrial equipment, and specifically relates to a water flushing process after chemical cleaning of a boiler. Background technique [0002] At present, the water flushing in the later stage of chemical cleaning of power station boilers usually adopts atmospheric pressure emptying of concentrated acid liquid or nitrogen top to empty concentrated acid liquid, and then washing with clean demineralized water, and directly using demineralized water for top row washing. Process method. When the direct emptying and flushing method is used, a large amount of air will enter the cleaning system. The cleaned economizer, water wall and other pipe inner wall active metal surfaces can easily react with oxygen in the air, causing secondary corrosion on the metal surface and prolonging The flushing time is not conducive to the implementation of the subsequent rinsing and passivati...

AI Technical Summary

Problems solved by technology

Among them, when the direct emptying and flushing method is adopted, a large amount of air will enter the cleaning system, and the active metal surface on the inner wall of the cleaned economizer, water wall, etc. is easy to react with oxygen in the air, causing secondary corrosion on the metal surface and prolonging the service life. The flushing time is not conducive to the implementation of post-rinsing and passivation processes; although the method of desalinated water flushing after nitrogen top discharge of concentrated acid solution or desalination direct top row flushing can avoid the secondary rust problem, it will increase the resistance of the system during the flushing process. Reduce the instantaneous flow rate of the flushing pump, and the internal flow environment of the boiler is relatively stable when the top row is flushed, and the internal disturbance of the system is small, which leads to problems such as partial flow, incomplete flushing, and long flushing duration during the flushing process, making the subsequent process Large fluctuations in the quality of reclaimed water not only increase the amount of flushing water and the difficulty of implementing subsequent process steps, but also generate a large amount of flushing wastewater, resulting in poor economic and environmental performance

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