Dust Agglomeration in an Electrostatic Precipitator

Dust agglomeration in an electrostatic precipitator (EP) during the sintering process taking place in an ironmaking plant was investigated. The dust agglomeration in the high sulfur flue gas dust hopper of the EP was very serious and did affect the removal of the dust from the hopper. The size of the agglomerate ranged from approximately 30-50 cm and was found to exhibit strong magnetic behavior. After combining actual operational observations and the physical and chemical test results, it was determined that the main factor resulting in the dust agglomeration in the EP was the unburned carbon, which was between 0.025% and 4.45% in the four samples of EP dust taken from different locations in the EP. In order to prevent fire accidents and dust agglomeration in the EP during the sintering process, the percentage of fine fuel particles (sized smaller than 1 mm) should be minimized; the average fuel particle size for the sintering process should be controlled at 2.5-3.0 mm, where the mass fraction accounts for approximately 80% of the fuel. In addition, strict sealing of the air box flue, the import and export flange, the expansion joint connection, the manhole door, and EP body should be carried out and maintained. Finally, the thickness of the bedding material should be more than 30 mm to ensure full combustion of the fuel used in the sintering process. This study provides useful information for the prevention of dust agglomeration in the EP during the sintering process.