WHAT IS THE ELECTROSTATIC PRECIPITATOR

This article will discuss the application of electrostatic theories that have been discussed in previous articles here. Application of electrostatic in the industrial world are used to address the problem of waste dust. Among other industries that apply the power plant, sugar mills and cement plants, one way is to use electrostatic precipitator (ESP).Electrostatic precipitator (ESP) is one alternative dust catcher with high efficiency (up to above 90%) and the range is quite large particles are obtained. By using electro static precipitator (ESP), the amount of waste dust out of the chimney is expected to only about 0.16% (effective capture of dust reaches 99.84%).

One of the most important component in the production process at the Sugar Factory and power plant is the boiler. Its function is as a place to heat water, thus producing steam that will be used for further processing. At the power plant, steam is used to rotate the steam turbine as the driving generator.Untuk do its work, the boiler requires the presence of heat used to heat water. This heat is supplied from a section called the combustion chamber or furnace, where the combustion chamber is equipped with a combustion appliance or burner. The results of combustion in the combustion chamber contains a lot of dust since the fuel used is coal, and the dust will be carried with the flue gases to the chimney. Before the flue gas exit through the chimney, the flue gas will pass through the grille of a electrostatic precipitator (ESP).

Figure 1. Electrostatic precipitator overview.

                                        Figure 2. Percentage capture of dust particles in the ESP.

How it Works Electrostatic Precipitator

The workings of the electro static precipitator (ESP) are (1) passing the exhaust gas (flue gas) through an electric field formed between the discharge electrode to the collector plate, flue gas containing dust grains initially neutral and charged at the time of passing an electric field, dust particles will be ionized so that the dust particles become negatively charged (-). (2) The dust particles are now negatively charged (-) is then attached to the plate-plate collector (collector plate), see figure 4. Dust collected in the collector plate is periodically transferred back from the collector through a vibration plate (rapping). The dust is then dropped into the tank (ash hoppers), see figure 1 and 2, and transported (moved) into the flyash silo with the way in vacuum or exhaled.

                                           Figure 3. The parts of the electrostatic precipitator.

                                                    Figure 4. The ionization process.

Electric Field Formation Process

The process of forming an electric field: (1) There are two types of electrode, which is negatively charged discharge electrode and the collector plate is positively charged electrode. (2) Discharge electrode placed between the collector plate at a certain distance (a distance between the discharge electrode with the collector plate). (3) Discharge electrode was given an electric direct current (DC) with a minus charge (see figure 3), at a voltage level between 55-75 KvDC (initial power source is 380 volts AC, then increased by a transformer to around 55-75 Kv and revamped into DC power by rectifiers, taken only potential negative only). (4) grounded collector plate (on-grounding) to be positively charged. (5) Thus, at the time of discharge electrode DC current then given electric field is formed on the chamber containing the electrode curtains and dust particles will be attracted to these plates, clean gas then moves into the chimney.

Electrostatic precipitator is one way to Steam Power (power plant) or other industries that could potentially generate dust waste into environmentally friendly, at least to reduce the pollutant content of the discharged through the chimney.

see also previous article "Mechanisms of steam soot blower erosion"

May be useful.