Development Of Pulse Ozone Generator And Its Application In Flue Gas Treatment

Nowadays the pollutant control of industrial boiler is facing a severe situation that a variety of pollutants must be removed at the same time in our country. The development of removal technology of various pollutants which is efficient and low-energy-consuming is uregent for solving the emission of flue gas, purification of equipment space and the cost increase of investment and operating. The removal of flue gas including a variety of pollutant which applies ozone oxidation technology combined with chemical absorption is available. The development of ozone manufacturing equipment with large capacity, high reliability and cost-effective is not only the main problem of the process line, but also the key to the application of ozone in China.The experiment system of ozone generator was established, which includes a device of power supply, a device of gas source drying and purifying, a device of ozone generating, a cooling device, a device of ozone detection and a device of exhausted gas treatment. Bipolar pulse power supply is used for ozone generator in order to produce ozone more efficiently, and to make a comparison with the traditional AC power supply. Compared to AC power. the bipolar pulse power supply can get a higher ozone concentration and energy efficiency. Under the same ozone concentration, the nitrogen dioxide yields are smaller when the power supply of the bipolar pulse was applied to the experiment. The experimental study on the coupling of the pulse power supply and the ozone generator is carried out, and it proves that the single discharge tube has a capacitance of 9.2 nF. The stable voltage and current waveform can be get when the resonant capacitor is 10 μF and the resonant inductance is 99 μH.In addition, the experimental focuses on the single discharge tube. The greater the flow rate,the higher the ozone and ozone energy efficiency when using air source, because the large flow of air can take away the heat inside the reactor, which is benefit to heat dissipation within the reactor. The best flow is the 40L/min. However, he ozone efficiency is better when the flow rate is smaller when using oxygen source, and the best flow rate is 5L/min. Experiments show that ozone concentration and energy efficiency will change with the change of voltage, current,frequency and flow. These changes are ultimately reflected in the change of energy density. In order to stabilize the efficient occurrence of ozone, the energy density selection should be 300-700 J/L when using air source, and the energy density selection should be 2000-7000 J/L when using oxygen source. The ozone concentration is 15.5 mg/L and the energy efficiency was 82 g/kWh when the voltage is 5 kV,the frequency is 3000 Hz,and the flow rate is 40 L/min under air source conditions. The ozone concentration is 144.7 mg/L and the energy efficiency is 133.9g/kWh when the voltage is 5 kV, the frequency is 2000Hz, the flow rate is 5 L/min under oxygen source conditions.Hundred discharge tubes is used in the 35 t/h demonstration project of the Qinghua plant.When the energy density increases, the ozone concentration changes will be divided into three stages. When the energy density is between 3 kJ/L and 6 kJ /L, the ozone concentration grows slowly as the energy density increases. When the energy density is 6 kJ/L,the ozone concentration won’t increase,or even decline. In order to use energy effectively,the energy density should be in the first stage in the practical application. At the same energy density,the greater the flow rate is, the higher the ozone production is. When the flow rate is 40m3/h, the ozone production is 4.9 kg/h, and the energy consumption of ozone is 7.1 kWh/kgO3, The equipment solves the key problem of the high cost of oxidant in the wet joint removal process,which makes the practical application of wet combined desulfurization and denitrification process possible.