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Air filter manufacturers: high efficiency filter leak detection?

Release time:

2022-07-05

Leak detection method of high efficiency filter: sodium flame method, counting scanning method, oil mist method, particle counter method. And there'shigh efficiency filterPAO leak detection method and instrument for detecting PAO aerosol concentration. This paper focuses on the PAO leak detection method of high efficiency filter and the tool to detect PAO aerosol concentration.

THE PRINCIPLE OF LEAK DETECTION BY SODIUM FLAME METHOD OF HIGH EFFICIENCY FILTER

The principle of sodium flame method is to use sodium chloride aqueous solution spraying and drying to form a mass of sodium chloride aerosol with a median diameter of about 0.4m as experimental dust. Dust air sampling was carried out before and after measuring the high efficiency filter screen, induced by sodium flame photometer, measured the photocurrent value related to dust concentration, and calculated the transmittance of the filter screen.

The experimental source is a single component on the sodium chloride salt spray, "quantity" is the brightness of the flame containing hydrogen salt spray, the main instrument is the flame photometer. The brine splashes with the agitation of the compressed air and dries to form a fine salt spray that enters the air duct. Samples were taken before and after filtration, containing salt spray, making the color of the hydrogen flame blue and improving the brightness. The concentration of salt spray in the air is judged by the brightness of the flame, so as to determine the filtration efficiency of the filter for salt spray. The average diameter of salt spray particles specified in the national standard is 0.4m, but the existing measured result in China is 0.5m. The measurement result of the middle diameter of the salt spray particle in the European actual experiment is 0.65m. With the popularity of other detection methods, the sodium flame method is no longer used in Europe. The relevant departments in China are revising the original national standards. As for whether to abolish the sodium flame law or continue to use it, the opinions have not yet been implemented.

高效过滤器

　　high efficiency filterIt is usually carried out after balancing the system airflow and each airflow. According to the specification, the deviation of each airflow and the designed air volume is less than 15%, so it meets the conditions of the air inlet close to the design wind speed. Therefore, after the air volume reaches the balance, the leak detection of the high efficiency filter should be carried out in time.

In engineering, the minimum path channel of a particle counter usually used for purification systems larger than 100 stages is 0.3m. Therefore,high efficiency filterThe particle concentration on the wind side is controlled to be 0.5 m, its concentration should be 3.5 104 PC/L, and the concentration of ordinary atmospheric dust is 5.3104-2.5105pc/L, which will reach the upper limit of the reading of the particle counter.

In many purification systems, the fresh air entering the circulating air tank is processed through a filter, and the concentration is much less than the atmospheric dust concentration, and the concentration will be further reduced after mixing with the ventilation. Therefore, the introduction of the atmosphere into the installed clean air conditioning system is a problem that needs careful consideration. In order to ensure the upstream particle concentration requirements of the air filter under inspection without destroying the system air balance, it is an ideal means to introduce a uniform concentration of artificial aerosols upstream. The concentration of the introduced aerosol is related to the efficiency of the installed high-efficiency filter and the resolution of the particle counter. The minimum bit of the particle counter is a bit and the minimum number is 0. The test instrument usually has a dead zone. If the required downstream concentration is less than 10, it is difficult to guarantee the validity of these data according to statistical principles.

At present, the filtration efficiency of 0.3m particles in the US DOP experiment is mostlyhigh efficiency filterClassification. Therefore, when using the count scan method to detect leaks, the measured particle size must be 0.3 m, which requires better upstream concentration. The efficiency of the high efficiency filter is 99.97%, the downstream concentration is within 3 significant figures, and the concentration of particles with a particle size greater than 0.3 m in the upstream air must be at least 6104pc/L. Using a high-efficiency filter with an efficiency of 99.99, when the particle concentration of upstream 0.3 m is about 2105pc/L, the particle concentration of upstream 0.5 m is much greater than 3.5x 104pc/L. Therefore, the use of the atmosphere as a dust source has been unable to meet the test requirements.

Air filter brand: what are the classification of air filter?

Liao Zengtai, Chairman of Wanhua Chemical Group, and his accompanying leaders visited Baoyuan Purification Co., Ltd.

Air filter brand: what are the classification of air filter?

Liao Zengtai, Chairman of Wanhua Chemical Group, and his accompanying leaders visited Baoyuan Purification Co., Ltd.

Air filter manufacturers: high efficiency filter leak detection?

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