Cleaning device and method for hollow fiber gas separation membrane module

Abstract

The invention discloses a cleaning device and method for a hollow fiber gas separation membrane module. The cleaning device is formed by the membrane module, a positive and negative bidirectional cleaning system, a ladder temperature purge system and an intermittent flow disturbance system. The positive and negative bidirectional cleaning system consists of a cleaning fluid tank, a cleaning pump, a pressure gauge, a positive and negative bidirectional cleaning pipeline and a blowoff valve. The ladder temperature purge system consists of an air compressor, a flowmeter, a control system, a heater, a purge pipeline and a blowoff valve. The intermittent flow disturbance system consists of an air compressor, a flowmeter, a control system, a disturbance gas flow generator, a check valve and a gas escape valve. The device disclosed by the invention can clean membrane modules in different pollution conditions; by a comprehensive cleaning effect of the intermittent flow disturbance system, the positive and negative bidirectional cleaning system and the ladder temperature purge system, performance of the membrane module is entirely repaired. The cleaning device and method are high in cleaning efficiency for the membrane module, good in effect, low in cost, simple in process and convenient to operate, and save enormous cost of replacing the membrane module.

Description

technical field [0001] The invention relates to the technical field of separation membrane cleaning, in particular to a cleaning device and method for a hollow fiber gas separation membrane module. Background technique [0002] Membrane separation technology is an efficient, fast and energy-saving new separation technology that can adapt to the requirements of contemporary new industries, so it develops relatively rapidly and is considered to be a high-tech with great development prospects in the 21st century. As an important part of membrane separation technology, gas separation membrane has been widely used in air separation, hydrogen recovery, natural gas removal of acid gas (H 2 S, CO 2 etc.), organic vapor (VOCs) recovery and gas dehumidification and other industries. According to the "Twelfth Five-Year Plan" development guide for the separation membrane industry, the world's gas separation membrane market is expected to rise to 760 million US dollars per year in 2020...

AI Technical Summary

Problems solved by technology

[0006] The cleaning device and method in the above patents have obvious technical shortcomings: 1. Most of the gas separation membranes are composite membranes formed by the combination of support layer and functional layer by physical adsorption. Cleaning with ultrasonic vibration or high-pressure airflow (especially backwashing) may cause Destroy the bond between the support layer and the functional layer, resulting in the peeling of the two layers, and even the scrapping of the membrane module

2. Due to the high packing density of the hollow fiber gas separation membrane module, the small diameter of the membrane filament, the relatively closed interior of the membrane module, the capillary effect of the membrane filament and the swelling and adsorption of the membrane material, a large amount of cleaning agent remains in the cleaned membrane module. Solvents such as sodium hypochlorite and sodium citrate will precipitate solids after volatilization, which will cause secondary pollution to the gas separation membrane module and reduce the cleaning efficiency and effect of the gas separation membrane module

3. Due to the fundamental difference between gas separation membranes and liquid separation membranes in membrane materials, membrane formation mechanism, separation principle, use conditions, storage methods and application fields, the size, strength and other characteristics of most gas separation membrane filaments are different from those of liquid membranes. The separation membranes are quite different. The pulsed high-pressure airflow in the above patents is likely to cause breakage at the joint between the membrane filament and the sealant (where the membrane filament is the most fragile), causing irreparable damage to the membrane module, and even leading to the scrapping of the membrane module.

4. The gas separation membrane module requires the membrane filament to be dry and clean during use. The cleaning method in the above patent will leave cleaning liquid in the membrane module, and impurities in the cleaning liquid will be introduced during use, which will affect the quality of the separation product.

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