1. Increasing flame temperature: High oxygen purity can effectively increase the theoretical combustion temperature of pulverized coal particles. Simulation results and actual measurements have proved that oxygen-enriched combustion of pulverized coal in cement kilns can significantly increase the flame temperature and overall temperature.
2. Accelerating the combustion rate: Oxygen enrichment can effectively reduce the time required for complete combustion. The complete combustion time is longer when the oxygen enrichment rate is lower.
3. Improving heat transfer: Enriched oxygen can improve the radiative heat transfer in the kiln. The air-supported flame emissivity is 0.2104, while it increases to 0.2245 and the radiative heat transfer increases by 20.4% when enriched oxygen of 25% is used to support the combustion. Enriched oxygen also improves the concentration of CO2 and water vapor in the output, which also helps to enhance the flame emissivity and the radiative heat transfer capacity.
4. Increasing heat utilization rate: Enriched oxygen can reduce the flue gas loss. Oxygen-rich combustion can reduce the heat loss of exhaust gas. It's been proved that 1% increase of oxygen purity can lead to about 2% ~ 4.5% decrease of the flue gas amount and the heat utilization rate is higher at the same temperature of the exhaust gas. The kiln gas intake reduces by 16% and N2 by 20% after oxygen is enriched to 25%.
5. Enhancing low quality fuel combustion: Oxygen enrichment reduces the ignition temperature. Coals with low calorific value have high ignition point and low flame temperature, which is an applicational problem. Oxygen-enriched combustion otherwise can reduce the ignition temperature of low calorific-value coals, and increase the flame temperature, which precisely solves the issue.
6. Improving cement quality: Oxygen-enriched combustion can reduce the content of free calcium oxide f-CaO in the cement clinker. And every 1% increase in oxygen concentration reduces the content of free calcium oxide by 0.075%. Oxygen-enriched combustion can improve the liter weight of cement clinker and enhance its strength by increasing the flame temperature.
7. Increasing the output of cement clinker: Oxygen-rich combustion can stabilize the thermal system and improve the output of cement clinker, increasing the machine-hour output of rotary kiln by about 5% on average.
As the world's largest supplier of vacuum pressure swing adsorption (VPSA) oxygen generation plant, PKU Pioneer can provide customers with stable, reliable, economical and high-quality O2 for oxygen-enriched combustion in cement kilns, helping cement manufacturers optimize their processes and significantly save production costs. PKU Pioneer has entered into cooperation with the largest cement manufacturer in Korea. With reference to the existing cases of oxygen supply for cement kilns in China, PKU Pioneer formulated reasonable application solutions to effectively help the user save coal consumption and improve cement production & overall efficiency.