Experience with Electrostatic Fly-Ash Collection Equipment Serving Steam-Electric Generating Plants

Statistical modelling and optimization of hydrolysis of urea to generate ammonia for flue gas conditioning

“…Conditioning agents cause adsorption of moisture on the particle surface, thus increasing its conductivity. Water, steam, ammonia (NH 3 ), sulfur trioxide (SO 3 ), sulfuric acid (H 2 SO 4 ), sodium chloride (NaCl) and hydrogen chloride (HCl) are used as conditioning agents to increase dust conductivity [9][10][11][12][13][14][15][16]. More complex organic mixtures have also been proposed for gas conditioning, but NH 3 is still the most effective conditioning agent [14][15][16].…”

Flue gas conditioning for reducing suspended particulate matter from thermal power stations

“…Previous studies reveal that the ash collection efficiency of ESP can be enhanced by utilizing flue gas conditioning (FGC) techniques, which involves addition of different types of chemical additives (viz., sulphur trioxide, ammonia, salts of sodium) and/or sprinkling of water to the flue gas, altering the properties of the fly ash and resulting in increased collection efficiency [20,[24][25][26][27][28][29][30][31][32][33]. The researchers have also demonstrated that sulphur trioxide conditioning reduces the electrical resistivity of fly ash particles [25,[34][35][36][37][38][39][40][41][42], whereas ammonia conditioning improves the surface charge density and cohesive properties of the particles [21,[43][44][45][46][47][48][49][50].…”

Electrostatic Precipitation Technology: A Different Viewpoint

“…Darby and Whitehead 36 considered that the correlation was with combustible sulfur in the coal, but later they excepted 37 some 0.5% sulfur lignites from the correlation. Reese and Greco 38 reported efficiency rising from 80% to about 96% as coal sulfur increased from 1.1% to 4.6%. Later Greco and Wynot 39 produced an apparent correlation in the opposite direction below 130°C.…”

“…Cuffe and Gerstle 44 reported that a precipitator guaranteed at 95% efficiency with a 2.4% sulfur coal performed at 75%. Reese and Greco 38 encountered a similar case where a precipitator guaranteed at 90% for a 2.5% sulfur coal collected only 20 to 60% of the fly ash. Lamb and Watson, 45 representing a large user of precipitators in Australia, could find no correlation with efficiency over the low sulfur range 0.3 -0.6%.…”