What should be paid attention to in the use of equipment flue gas desulfurization and denitrification

In the selection of bag dust removal equipment, the fly ash composition analysis was carried out in order to select suitable fabrics and processing technology, and also to appropriately increase the filter area of bag dust removal equipment, and reduce the filtration speed of flue gas to 0.8-0.85m/ min, while the conventional configuration is 0.9-1.0m/min; in the initial stage of flue gas, it is necessary to pre-coat the new filter cloth with special reaction additives or coarse fly ash to capture the smoke in the flue gas The surface of the powder cake layer will not invade the inside of the filter cloth.

Keep the pressure loss of the filter cloth at a low value for a long time, prolong the pressure loss of the filter cloth at a low value for a long time, and prolong the service life of the filter cloth. During the operation, in order to avoid the CaSO3.1 in the circulating ash The /2H2O/CaSO4 content is too high to affect the air permeability of the filter bag. You can add coarse powdered coal dust to the circulating ash bin at intervals of about 7 days to adjust the composition and particle size of the circulating ash, which can also effectively prevent the circulating ash Bonded on the filter bag to reduce the filter resistance of the filter bag and increase the service life of the filter bag.

Now, circulating semi-dry flue gas desulfurization and denitrification technologies such as NID and CFB are more and more used in power plant renovation projects, and the equipment layout basically adopts the conventional supporting mode, that is, the desulfurization and dust removal equipment is directly connected after the air preheater, and then by An induced draft fan is used for control. This matching mode requires the power plant to be shut down for at least 2 months, and the original dust removal equipment needs to be dismantled. In order to seek a transformation plan with less investment, short shutdown time, and retaining the original equipment as much as possible, the manufacturer of the flue gas desulfurization and denitrification project developed a desulfurization and dust removal project based on the No. The process configuration in which the circulating semi-dry flue gas desulfurization, denitrification and dust removal equipment is arranged between two series induced draft fans.

The boiler flue gas from the air preheater first passes through the original 3 electric field electrostatic precipitator, and after pre-dust removal, it is switched into the reactor or the chimney in two ways under the action of the original induced draft fan. The switching of the flow direction of flue gas desulfurization and denitrification by ammonia method is mainly through two bypass baffle doors installed on the outlet flue of the original induced draft fan, two inlet baffle doors at the front of the reactor and one on the main outlet flue of the booster fan. Exit flapper door to achieve.

When desulfurization, close the bypass baffle door, open the inlet baffle door and the outlet baffle door, and the flue gas enters the reactor, settling chamber, bag filter, desulfurization booster fan outlet main flue in sequence, and returns to the original flue to enter When the chimney is not desulfurized, the bypass baffle door is opened, the inlet baffle door and the outlet baffle door are closed, and the flue gas is discharged from the original flue to the chimney. The original flue is used as a bypass of the bag filter, which can save the construction cost of the bypass flue of the subsequent bag filter. Gas recirculation.