How to quickly resolve the excessive pressure difference and low dust removal efficiency of the baghouse

Baghouse is now the main industrial dust removal equipment in various industries and plays a very important role in environmental protection. Therefore, in daily production work, the pulse baghouse should be maintained frequently to avoid problems. This article introduces the reasons and solutions for excessive pressure difference and low dust removal efficiency of the baghouse.

Excessive differential pressure

1. The bag filter of the bag filter is damaged

The service life of the bag filter bag is limited. After using for a period of time, the dust will cause the filter bag of the bag filter to wear, and small holes will appear in the cloth bag. When the dust concentration of the exhaust gas is increased, and the airflow containing more dust passes through the fan at high speed, it will cause significant wear of the fan casing and impeller. Check the bag filter for damage to the baggage. If only a few bag filter bags are damaged, seal the hole of the plate with an iron cover to ensure that the discharged dust concentration meets the standard. (How to find the damage of the filter bag, please click: How to find the damage of the bag filter and the internal leak welding? The inspection methods and processing steps are here, and the problem can be solved quickly to resume production.) If the filter bag must be replaced, the same bag type is recommended All dust-removal cloth bags of the dust collector are replaced at the same time, ensuring that each filter bag has the same resistance.

2. Air leakage from the bag dust collector

It is difficult to detect the leak point with the naked eye. It is necessary to open the bag filter exhaust fan during the inspection, and at the same time, the bag filter air door should be closed. If you can hear the sound of "呲 呲" to prove that the place is a leak point, you can find the leak point and weld it. The aged flexible hoses between the air exchange pipe, the directional valve, and the promotion valve should be replaced in time to prevent aging damage and leakage.

3. The filtering wind speed is too high

The concentration in the dust is too high, and the filtering wind speed of the filter bag is too high at this time, which causes the pressure difference of the filter bag to be too high. The dust removal load of the bag filter and the filtering wind speed of the filter material should be appropriately reduced, that is, increase the filtering area and reduce the filtering wind speed of the filter material.

4. Improper parameter setting

If the bag filter has a poor dust removal effect and a large pressure difference, it will cause the filter bag to be reduced in tension and the dust on the filter bag will be too thick. This kind of problem should reset the relevant parameter of the pulse injection system.

5. The temperature of the dusty gas is too high

The dust-containing gas of the pulse bag type dust collector is too high, and the thermal insulation measures not taken by the dust removal system will make the temperature difference between the dust in the dust collector pipe and the external environment, and water vapor and condensation will occur during the heat exchange process. The humidity of the dust is increased, so insulation measures should be taken.

6. The material of the filter bag is not suitable

The filter bag material of the pulse bag type dust collector does not match the dust in the gas, which will cause some air holes to be blocked. Therefore, a reasonable dust removal filter bag should be selected according to the characteristics of the dust removal gas.

7. The concentration of dusty gas is too high

If the concentration of the processed dust-containing gas is too high, the filtering wind speed of the dust collector will be too high, which will lead to excessive pressure difference. The dust removal load and filtering wind speed of the pulse bag dust collector should be appropriately reduced.

Low dust removal efficiency and high emission concentration

1. Selection of filter bag

The filter bag should be made of wear-resistant and high-temperature resistant materials. Glass fiber cloth / felt, NOMEX, needle felt, P84 needle felt, etc. are more common materials.

2. The quality of the filter bag

The performance and quality of the filter bag largely determine the dust removal effect, working efficiency and service life of the bag filter. Poor quality filter bags are prone to breakage and bag burning problems during production.

3. Control of temperature

Generally, the temperature of the filter bag is 200 ° C, so the inlet temperature of the processing facility should be controlled below 200 ° C. When the flue gas passing through the long smoke pipe reaches the dust collector box, the temperature can be lowered below 200 ° C. In special cases, water cooling can be performed, and a cooler can be installed at the main smoke pipe.

4. Selection of fan

The practice has proven that induced draft fans are better than blowers.

5. Cleaning method

There are three types of bag dust removal methods: pulse backflushing, backflow backflushing, and mechanical vibration. Pulse backflushing bag dust collector can adjust the intensity and frequency of pulse backflushing, and it has a good ash cleaning effect and is widely used.

6. Air leakage and resistance

Although the dust removal efficiency of the bag filter is theoretically 99%, it is difficult to achieve it due to the effects of air leakage and resistance. The lower the air leakage rate, the better the dust removal effect; the resistance has an effect on the dust removal effect, often emptying the filter bag, reducing the resistance, can improve the dust removal effect.

7. Dust collection hood layout

The dust collection hood should be as close as possible to the furnace head to make it easier for the dust to enter the hood, increase the amount of dust collected, and reduce fugitive emissions pollution.

8. Equipment maintenance

Instruments and equipment and cloth bags are easily damaged. Repair and replace the cloth bags in a timely manner. Check the clean air chamber and filter bag regularly. You can also check whether there is dust accumulation, water vapor or rust spots according to the abnormal fluctuation of the differential pressure in the chamber. Once the above situation occurs, it indicates that the filter bag is damaged or the operating conditions are incorrect.

9. Filter speed

The filtration speed should be based on the properties of the soot or dust, the application, the dust particle size, viscosity, gas temperature, moisture content, etc.

When the particle size of the dust is fine, the temperature and humidity are high, the concentration is large, the viscosity is easy to choose a low value, otherwise, a high value can be selected, but generally, it should not exceed 1.5m / min. For dust with large particle size, normal temperature, dry, non-sticky, and low concentration, select 1.5-2m / min.

10. Filter area

The larger the filtering area, the higher the dust removal efficiency, but the cost will increase accordingly. Therefore, the air volume should be calculated in advance, and then the corresponding dust collector model should be selected.

11. Secondary dust removal

A settling chamber is installed in front of the dust collector box to form secondary dust removal. Dust-containing gas flows slowly in the sedimentation chamber, and the dust particles are separated by the effect of its own gravity, which can remove a part of large particles of dust, reduce the temperature, and reduce the pressure of the dust collector.