Ionization and Conduction of Gases in Pipeline Electrostatic Precipitator
The process of gas ionization in pipeline ESP is like this. Air is almost an insulator that can not conduct electricity under normal conditions. There are no spontaneous ions in the gas, so there is no current actually passing through. It must rely on external forces to ionize. When gas molecule gains energy, it may make the electrons in gas molecule detach and become free electrons. These electrons become the medium to transport current. At this time, gas has the ability of conducting electricity.
Because the electrons and positive ions formed by gas ionization move in the opposite direction under the action of electric field, a current is formed, and the gas conducts electricity at this time, thus losing the insulation performance of the gas in its normal state. The energy of gas ionization can be transformed into ionization energy.
Gas ionization can be divided into two categories: spontaneous ionization and non-spontaneous ionization. Non-spontaneous ionization of gases occurs under the action of external energy. The corona current is formed by the movement of electrons, anions and cations in the gas. Gas non-spontaneous ionization and spontaneous ionization are not necessarily proportional to the current passing through the gas and the potential difference. When the current increases to a certain extent, even if the potential difference is increased again, the current will not increase and a saturated current will be formed.
The completion of the gas conduction process in the pipeline ESP only relies on a small amount of free electrons in the atmosphere. At BC stage, the voltage rises to C', but the current does not increase. At this time, all electrons get enough kinetic energy to collide with neutral molecules in the gas. When the voltage is higher than C', because the energy obtained by the electrons in the gas is enough to ionize neutral molecules in the gas colliding with them, new ions are produced in the gas and current is transmitted by the gas ions.