How to protect the dust removal filter bag from oxidation damage?
1. Increase diversion flow
Increase diversion flow. This is actually the demand for compressed air.
(1) Use small diameter filter bag: increase its specific surface area. Under the same air distribution, the volume decreases, and the amount of compressed air required also decreases.
(2) Online ash removal: In order to increase the flow, it is necessary to use online ash removal. "Offline" ash removal cuts off the flue gas channel of the warehouse, so if there is no flue gas supplement, the drainage effect will be inappropriate.
(3) Install a suitable nozzle, which has two functions: one is to increase the flow; The first is to keep the ash cleaning pressure transferred to the bottom of the filter bag. Its shape has a great impact on the ratio of entrainment flow rate to air injection rate. When compressed air is injected into the internal nozzle, the nozzle acts as a jet pump, and generates negative pressure in the filter bag through high-speed injection, so that purification gas equivalent to 80% of the pulse air volume can be extracted from the upper part of the filter bag, and then enters the filter bag through the nozzle for ash removal.
2. Reduce the oxygen content and dosage of compressed air
The volume ratio of oxidation in air is 20%, which is relatively high. Therefore, reducing the oxygen content in this part is an important aspect.
(1) Reduce the number of injection: the pressure difference control method is usually more scientific than the time sequence control method, which can reduce the number of pulse injection. Reducing the number of injections means reducing the amount of mixed compressed air.
(2) Compressed air source with low oxygen content is used for ash removal: if compressed nitrogen is used for ash removal, the oxygen content in flue gas will not increase or even decrease.
(3) Reduce air leakage rate: improve the sealing effect of manufacturing and installation quality and reduce air mixing.
(4) High-pressure pulse dedusting: due to the high pressure, large flow and small flow of compressed air, if the auxiliary "online" mode is adopted, the amount of compressed air will be much smaller.
(5) Reduce the residence time of compressed air: use online ash removal. The residence time of compressed air is less than 1 second, which can greatly shorten the reaction time, while the offline mode can reach several minutes.