Ultrafiltration membrane leak detection method based on acid-base indicator

Abstract

The invention provides an ultrafiltration membrane leak detection method based on an acid-base indicator. The method specifically comprises the steps that firstly, an indicator liquid membrane is attached to the end face of a membrane hole of a membrane assembly; then, reaction gas is introduced into a membrane shell of the membrane assembly, the reaction gas can react with the indicator to change color, and the reaction gas is continuously introduced for 30-60 s in a pressure maintaining mode; finally, whether the indicator at the opening of the membrane hole changes color or not is observed, if the indicator changes color, the membrane silk corresponding to the membrane hole at the color changing position has an air leakage point, the membrane hole at the position is marked, and follow-up corresponding repairing measures are taken according to the marking situation, the leak detection method can be directly carried out in a dry state, pollution to the ultrafiltration membrane is small, and secondly, the error-tolerant rate of the leak detection process is high; meanwhile, the judgment mode is simple and reliable.

Description

technical field [0001] The invention relates to the technical field of ultrafiltration membrane detection, in particular to an ultrafiltration membrane leak detection method based on an acid-base indicator. Background technique [0002] During the production process of the hollow fiber ultrafiltration membrane module, due to the defective points of the membrane filament itself and the process of the membrane filament being loaded into the membrane shell to make the module, some physical damage will inevitably occur. These defects and physical damage points will lead to If the membrane wire fails, normal water treatment cannot be carried out, and shielding treatment must be carried out before leaving the factory, otherwise the water quality of the produced water will not meet the standard. [0003] The current common detection method in the industry is to inject compressed air or nitrogen with a certain pressure into the closed membrane shell of the membrane, and completely i...

AI Technical Summary

Problems solved by technology

[0002] During the production process of the hollow fiber ultrafiltration membrane module, some physical damage will inevitably occur due to the defects of the membrane itself and the process of putting the membrane into the membrane shell to make the module. These defects and physical damage will lead to Membrane failure, unable to perform normal water treatment, must be shielded before leaving the factory, otherwise the water quality of the produced water will not meet the standard

[0003] The existing common detection method in the industry is to inject a certain pressure of compressed air or nitrogen into the airtight membrane shell of the membrane, completely immerse the membrane module in water, and observe whether there are continuous bubbles coming out of the membrane pores. If there are continuous bubbles, the corresponding membrane filaments need to be repaired. This judgment method requires inspectors to observe the underwater situation through the water surface, which is difficult to operate, and when there are many bubbles, it is difficult to judge accurately. The soaked ultrafiltration membrane also needs to be dried, which is not convenient for long-term storage

[0004] One of the existing better judgment methods is to brush the detection liquid on the end of the ultrafiltration membrane membrane in a dry state, and then pass gas into the membrane shell. When there is a leak in the membrane, the corresponding membrane Bubbles appear in the detection liquid at the end. It is more convenient to judge whether there are bubbles than to observe the bubbling underwater. However, the bubbles are easy to burst during the process of swelling, and on the other hand, they are easy to expand to the membrane of the attachment. It is also easy to cause misjudgment at the opening of the wire