Cleaning method of low-temperature multiple-effect seawater desalination evaporator

Abstract

The invention relates to a cleaning method of a low-temperature multiple-effect seawater desalination evaporator, which belongs to the technical field of thermal seawater desalination. The method comprises the steps as follows: washing by water with the temperature being 20 to 30 DEG C and the flushing time being 30 to 60 minutes; carrying out precleaning by pre-cleaning liquid with the pre-cleaning time being 30 to 120 minutes; carrying out acid cleaning by pickling fluid containing pickling inhibitor with the acid cleaning time being 2 to 12 hours; adjusting pH value to 6.5 to 7.5 by alkali liquor; washing by water; carrying out passivation by passivating liquid with the passivation time being 2 to 12 hours. The method has the advantages that the performance of a low-temperature multiple-effect seawater desalination evaporator can be better recovered after the cleaning, and the method is economic, practical, simple and effective. The method is particularly applicable to the cleaning to low-temperature multiple-effect seawater desalination evaporators, and also applicable to the cleaning to heat exchangers and evaporators for seawater medium.

Description

technical field [0001] The invention belongs to the technical field of thermal seawater desalination, and in particular relates to a cleaning method for a low-temperature multi-effect seawater desalination evaporator, which is suitable for cleaning the low-temperature multi-effect seawater desalination evaporator. Background technique [0002] my country is one of the areas where water resources are seriously lacking, especially in its coastal areas. With the inevitable trend of heavy industry shifting to the sea, the problem of water shortage will become more prominent. Seawater desalination is the best way to get fresh water from the sea to solve the problem of water shortage. [0003] Commonly used seawater desalination methods are divided into two types: thermal method and membrane method, including thermal multistage flash distillation, low temperature multi-effect distillation and compressed steam distillation. Low-temperature multiple-effect distillation (abbreviated...

AI Technical Summary

Problems solved by technology

[0006] Some current descaling methods often require mechanical or expensive chemical treatment to remove scale

The mechanical descaling method is too time-consuming and difficult to control, and because the heat transfer tubes in the low-temperature multi-effect seawater desalination evaporator are thin and thin, the descaling effect is not good if the force is too small, and the heat transfer tubes will be damaged if the force is too large

However, the common chemical treatment often consumes a lot of chemicals, and the procedure is relatively cumbersome, and it often needs to be soaked for a long time, which has a great impact on production and high cost.