Bag filter life and operation

In the case of variable coal types and irregular operation in China, the service life of the bag filter bag exceeds 20,000 hours, but it has exceeded 30,000 hours abroad. The life of the filter bag is guaranteed to be 30,000 hours, which is selected in conjunction with the 4a overhaul. Therefore, if you strictly follow the above design requirements and follow the following operational measures, you can still get it.

(1) Reduce the temperature of the smoke, prevent air leakage, and debug the distribution of hot and cold airflow.

a. Repair the air preheater and the economizer to increase the heat exchange efficiency and reduce the flue gas temperature to below 150 °C.

b. Prevent gas leakage from the furnace, air preheater, flue and dust collector, and reduce the oxygen content (less than 8%) in the dust of the dust collector.

c. The dust collector should be fully insulated to prevent acid corrosion caused by condensation.

d. Debug the distribution of cold air and hot air.

(2) Control the injection pressure and extend the injection interval. The lower production resistance of the new production equipment can be appropriately reduced by the injection pressure, pulse width and extended blow molding interval, which is very advantageous for extending the life of the filter bag. When the operation is about 1 or so, the resistance of the filter bag will gradually stabilize, and the injection pressure can be appropriately adjusted and the injection interval can be shortened as needed.

(3) Spray the filter bag before starting. Check if there is enough ash in the ash tank, start the induced draft fan, and then pre-spray the filter bag into the bag filter until the surface of the dust bag has a dust collecting layer of 2 to 3 mm thick (about 3 hours or more). For a long time, the boiler can be ignited. In order to protect the filter bag, the pre-spray condition of the filter bag should be checked before each boiler ignition and the pre-spray effect should be checked. The ignition oil gun is well atomized and completely burned, preventing a large amount of unburned oil droplets from being carried into the furnace, thereby causing the paste bag.

(4) In normal operation, the pressure difference of the filter bag is greater than 1500 Pa (electricity + bag 1200 Pa), and the cleaning is stopped at 800, 900 Pa. The typical pressure difference of the new bag is 1.0 kPa, and the service life is 2.5 kPa at the end of the service life!

(5) When the boiler is in normal operation, the oxygen content in the furnace should be kept at 2%~3%, and the oxygen content at the inlet of the bag filter should be less than 8%.

(6) When the exhaust gas temperature reaches 150 °C, the alarm is protected. The furnace can take measures such as reducing the load, reducing the air supply and sucking the air. When the smoke temperature reaches 160 °C, the second alarm, continue to reduce the load and other measures to achieve the purpose of reducing the temperature of the smoke. A protective spray was started while the 170 °C alarm was reached. Monitor the downward trend of the flue gas temperature, stop falling below 160 °C to stop the injection, continue monitoring until the exhaust gas temperature returns to normal. Emergency shutdown should be exceeded at 180 °C.

(7) When it is judged that there is water leakage in the water wall tube from the water level, flow rate, furnace negative pressure, air leakage sound and other parameters, the delay time is not allowed, and emergency stop should be set to prevent the bag from being stuck. Try to install a hygrometer at the outlet of the air preheater to detect the moisture content in the flue gas, detect the leak of the blast tube early, and take emergency measures in advance.

(8) Preventing the unburned coal powder in the highly volatile bituminous coal from accumulating in the dead angle of the flue and the dust collector, or after pumping the pulverized coal into the furnace, when the temperature of the pulverized coal reaches a certain temperature, the boiler is suddenly caused Extinguished to cause secondary combustion. The entrance to the dust collector suddenly rises a lot. Stop the furnace immediately and take measures such as stopping the fan, sending the fan and feeding the powder.

(9) During operation, it was found that the pressure difference of a certain unit became small, resulting in an increase in the discharge concentration, that is, a damaged bag, and the small air flow through the filter bag caused the filter bag to quickly open the surrounding filter bag. Destruction, causing catastrophic losses. Therefore, it is necessary to detect the dust collector and replace or close the damaged bag in time. The position of the broken bag can be detected by spraying the phosphor and using an ultraviolet lamp that illuminates the phosphor.

(10) If the filter bag is changed online, the airflow must be restricted until the filter bag is completely adjusted. That is, the new bag should be pre-coated with a dust layer to make it as good as other bags.

The above is the sharing of Xiaobian, I hope that the results of Xiaobian can provide some help for friends in need. For more information, please pay attention to the official website of Yongming Machinery.

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