Operation method of pre-coating filter bag
1、The pre-coating of the filter bag should cut off and stop the ash cleaning system before the combustion or the start of the production process. Open the air inlet valve of the dust collector (including the air inlet and outlet valves of each filter bag chamber).
2、Start the fan to gradually increase the air flow of the dust collector until it reaches about 70% of the design air volume, and record the internal and external resistance of the dust collector filter bag in each room.
3、Put dry and oil-free pre-coated powder into the opening of the main air inlet duct of the dust collector (usually the flue gas test port).The ash mesh number is required to be less than 200 meshes, and the moisture content is less than 1%. Put in the ash powder of 350-450g per square meter of filtration area.
4、Before starting to add powder, make sure that the air volume of the induced draft fan is above 70%, the bypass valve must be closed and the poppet valve is online. The fan runs under load for about 20 minutes until the end of pre-coating to ensure a more even and smooth distribution in each ash hopper.
5、When pre-painting, the rising pressure difference in each chamber reflects. For example, if the pressure difference is 100Pa at the beginning, it must be increased to at least 350~400Pa after precoating, that is to say, it must be increased by 250～ If not, it indicates that the pre-graying has failed and needs to be repeated.
6、After the pre-coating work is completed, stop the fan and arrange for personnel to enter the clean air chamber of the dust collector for inspection. If there is dust leakage in the hole of the flower plate or the electric welding between the flower plate and the box body, check whether the seal between the bag head of the filter bag and the flower plate is tight.
7、After pre-coating the filter bag, if there is no problem, the system runs to the normal design parameters, then the dust removal system of the dust collector is turned on, and the dust collector enters normal operation.