Measures to extend the life of filter bags
- Appropriate filtering wind speed
Generally, when the dust concentration is high, the filter wind speed should be lower, otherwise higher. The smaller the dust particles, the smaller the filter wind speed, and vice versa. If the filtering wind speed is too high, it will increase the load of the dust filter bag and increase the filter resistance, resulting in a short service life and low efficiency of the dust filter bag. If the filter wind speed is too small, the filter area will be increased and the dust collector will be too large.
- Pre-spray to prevent adhesion of oil stains
When the boiler is ignited and operated at low load, it usually takes a long time to put oil. If the oil fume passes through the filter bag and the it is not treated in advance, it will cause irreversible damage to the filter bag, so it is necessary to pre-spray the filter bag. It is generally believed that after pre-spraying (lime powder or fly ash can be used), when the pressure difference of the filter bag increases by 250 to 300 Pa, the spraying is considered qualified. And the cover of the clean air chamber can also be opened to check that the dust accumulation of the cloth bag is even.
- Proper blowing pressure and pulse width
Adjust the proper blowing pressure and pulse width to avoid excessive blowing pressure. Generally, the newly replaced filter bag should control the blowing pressure of 0.20～0.25MPa. With the extension of the running time of the filter bag, its own resistance gradually increases, and the injection pressure can be appropriately increased to 0.35MPa to improve the injection effect.
- Suitable exhaust temperature
Strictly control the change of exhaust gas temperature to prevent it from being too high or too low and avoid abnormal combustion conditions. The flue gas temperature suddenly rises or is too high for a long time, causing the filter bag to burn. On the contrary, the exhaust gas temperature is low, and condensation occurs, which causes the filter bag to harden. Both conditions will have an irreversible and significant impact on the life of the filter bag.
- Maintenance before and after shutdown
Before the cloth bag stops running, it is generally necessary to continue spraying for several cycles to keep the dust accumulation of the filter bag to a minimum, and at the same time transport all the ash in the ash hopper to the ash storage. In the cold winter, do a good job of heat preservation of the dust collector, regularly check the air leakage of the dust collector, and conditionally increase the heating device to ensure that the filter bag is dry. Start with the design, installation, operation and maintenance of the bag filter, implement the details, increase the service life of the bag filter bag, reduce the operating expenditure of the environmental protection device, and achieve the emission of smoke and dust.