Electrostatic precipitator configuration

The HD configuration is used mostly in coal-fired applications because the temperature of the flue gas between the economizer and the air preheater is optimal for the catalyst activity ( 3(K)-400X) and because dust removal is usually accomplished by means of cold electrostatic precipitators. Ammonia slip must be kept at low levels (<5 ppm or even below 2-3 ppm), and SO2 oxidation must be as low as 0.5-1.0% in order to minimize the formation and deposition of ammonium sulfates in the heat exchanger and in the fly ash. 

The LD configuration typically is applied in the plants where the residual dust content and the resistivity of the dust are compatible with the use of hot electrostatic precipitators. One of the advantages of this system is the reduced deterioration of the monolithic catalyst. 

Figure 1 SCR process configurations. FGD flue gas desulfunzation B boiler, APH air preheater ESP electrostatic precipitator GGH gas-gas heat exchanger, H heater. (From Ref. 20.)...

An improved configuration of the DC-11 gasA apors recovery system integrated an electrostatic precipitator (EP) replacing the cotton wool filter (denoted as DC-111). Gas enters the bottom of the precipitator and leaves the top, while a liquid outlet situated at the lower part of the precipitator serves for the collection of the captured pyrolysis liquids. 

The CRES CFB biomass fast pyrolysis pilot plant performance and availability was improved after amendments to the pyrolysis vapors collection and recovery train. The latest configuration adopted (DC-III), namely a scnibbing-type device followed by an electrostatic precipitator, resulted in ... 

Electrostatic precipitator Batch process load electrodes, then clean via wet spray or mechanical rapping. For particle conductivity between 10 and 0.01 reciprocal ohm m. Prefer negatively charged configuration. May need to adjust conditions to get particle conductivity into acceptable range. For particles >10 pm, use 38-m plate area per m /s gas flow 1 pm, use 100-m plate area per m /s gas flow 0.4 pm, use 120-m plate area per mVs gas flow. 

Model III Side-by-side configuration Higher pressure operation Lower regenerator elevation Improved spent catalyst regeneration Elimination of electrostatic precipitator and waste heat boiler... 

Electrostatic precipitator Batch process load electrodes then clean via wet spray or mechanical rapping. For particle conductivity between 10" and 0.01 m. Prefer negatively charged configuration. May need to adjust conditions to get particle conductivity into acceptable range. 

FIGURE 3.5-8 Electrostatic precipitator hardware configuration. Courtesy of the MikroPul Coip. 

---