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How to choose industrial dust filter bags?

June 02,2023

The selection of industrial dust collection filter bags is crucial as it directly affects the dust collection effect of bag house. The selection of industrial filter bags should be based on the following factors: shape, filtration method, gas temperature, humidity, chemical properties, particle size, dust concentration, filtration wind speed, dust removal method, and other factors.

The shapes of SFFILTECHindustrial filter bagsare mainly divided into three types: circular, flat, and irregular.

1. Circular filter bag: The filter bag is cylindrical. Its specification is based on the diameter × Length is D × L (mm) represents;

2. Flat filter bag: The filter bag is flat, including rectangular and trapezoidal shapes, and its specifications are based on the circumference × Length is P × L (mm) represents;

3. Irregular filter bag: A filter bag with a unique shape, which is represented by the characteristic parameters of its construction.

There are two main filtering methods: SFFILTECH filter bags haveinternal filteringandexternal filtering.

1. SFFILTECH internal filtration industrial filter bag: After the dust containing gas is filtered on the inner surface of the filter bag, the dust is blocked on the inner surface of the filter bag. This filtering method is called internal filtration;

2. SFFILTECH external filtration industrial filter bag: When dust containing gas passes through the outer surface of the filter bag for filtration, the dust is blocked on the outer surface of the filter bag, and this filtering method is called external filtration.

The material of industrial filter bag filter materials is generally determined based on the properties of dust containing gases, dust properties, and the cleaning method of the dust collector.

1. The temperature of the dusty gas selected based on its properties is an important factor in the selection of filter materials, usually divided by 130 ℃. Normal temperature filter materials below 130 ℃ and high temperature filter materials above 130 ℃ are used. To ensure the normal operation of the filter bag, the corresponding filter material needs to be selected based on the temperature of the dusty gas.

Dusty gases can be classified into three states based on relative humidity: dry gases with a relative humidity below 30%; 30% -80% are in a general state; Above 80% is a high humidity gas. High humidity gas cooling can cause condensation, causing dust to settle in pipelines or filter bags. Therefore, high humidity gases should use filter materials such as SFFILTECH nylon or SFFILTECH glass fiber, which have a smooth surface, long fibers, and are easy to clean. When designing, circular cloth bags should be used instead of flat cloth bags with complex shapes and compact structures. Various types of furnace flue gas and chemical waste gas often contain acids, alkalis, strong oxidizing gases, and are subject to the cross influence of temperature and humidity. Therefore, the selection of filter materials for filter bags should be comprehensively considered.

2. According to the nature of the dust, when selecting filter materials for wet and deliquescent dust, attention should be paid to ensuring that the filter materials are smooth and non-fluffy. For dust with strong adhesion, it is recommended to use filament non fluffy fabric filter material. After comprehensive consideration, it is believed that nylon and glass fibers are superior to other filter materials. When the fluidity and friction of dust are strong, it will directly wear the cloth bag and reduce its service life. Particles with rough surfaces and irregular diamond shapes exhibit 10 times greater wear resistance than smooth and spherical particles. The larger the particle size, the greater the wear resistance. Therefore, for abrasive dust, it is advisable to choose filter materials with good wear resistance.

3. Choose industrial filter bags according to the cleaning method of the dust collector. The cleaning method of the dust collector is another important factor in selecting the quality of the filter material. Bag dust collectors with different cleaning methods choose different types of filter materials with different structures due to different cleaning amounts and bag shapes.

There are two common cleaning methods: mechanical vibration and chamber pulse. The cloth bag of the mechanical vibration dust collector is an internal filter type. Dusty gas enters the filter bag mouth and after filtration, the dust adheres to the inside of the filter bag, allowing clean gas to be discharged. When cleaning, mechanical devices are used to shake or vibrate the filter bag to shake off the dust adhering to the inner surface of the filter bag. Considering that this cleaning method requires the use of thin, smooth, and soft filter material, which is conducive to transmitting vibration waves and can form sufficient vibration force on the filter surface, it is recommended to use satin or twill fabric as the material for this type of filter bag.

The pulse filter bag compartment dust collector uses compartment cleaning. When cleaning the ash, isolate each box one by one and take turns. The pulse and cleaning cycle of each chamber are automatically and continuously carried out by the cleaning program controller according to the pre-set program, ensuring the effectiveness of compressed air cleaning. During normal operation of the equipment, dusty gas enters the ash hopper through the air inlet. Due to the rapid expansion of the gas volume, a portion of the coarser dust particles fall into the ash hopper due to inertia or natural sedimentation, while the rest of the dust particles rise with the airflow and enter the bag room. After being filtered by an industrial filter bag, the dust particles are retained on the outside of the filter bag. The purified gas enters the upper box from inside the filter bag, and is then discharged into the atmosphere through the valve plate hole and exhaust port, Thus achieving the purpose of dust collection. As the filtration continues, the resistance of the bag house also increases. When the resistance reaches a certain value, the cleaning controller sends a cleaning command, first closing the lifting valve plate and cutting off the filtered airflow; Then, the dust removal controller sends a signal to the pulse solenoid valve, and as the pulse valve sends the high-pressure reverse airflow used for dust removal into the bag, the industrial filter bag rapidly swells and produces strong shaking, causing the dust on the outside of the filter bag to shake off, achieving the purpose of dust removal. Due to the reliance on the impact and vibration of compressed air to achieve dust removal, it is required to use thick, wear-resistant, and strong tensile resistant filter materials. SFFILTECH chemical fiber needle felt or compressed felt filter materials are preferred, with a unit area mass of 500-650g. In short, it is necessary to choose appropriateindustrial dust collection filter bagsbased on the actual situation, according to the different usage environments.

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