Abstract:
In order to get the particle emission characteristics of different stationary sources in cement enterprises, the field test was carried out with self designed dilution collection system of PM
2.5 located at Guanzhong area in Shaanxi Province. The results showed that the kiln head mainly emitted smaller particles and the size distribution was related to the condensation, coagulation, coacervation and other mechanisms. The kiln tail, coal mill, crushing and cement mill mainly emitted larger particle sand their size distribution were related to the physical properties such as crushing and grinding of raw materials, fuels and clinker; In consideration of the standard dry flow rate of exhaust gas, the control points of stationary source PM
2.5 are kiln head, coal mill, kiln tail, cement mill and crushing in turn. The overall level of particles mass concentration of Aitken mode and accumulation mode in kiln head was obviously higher than that of kiln tail, coal mill and crushing. The difference between maximum values was about 3 times to 1 orders of magnitude. The common characteristics of mass concentration distribution in the kiln head, kiln tail, coal mill and crushing was that the most particles mass at different levels was larger than 0.1 μm in the particle size distribution spectrum of PM
10, and the mass change was more intense. The overall level of particles number concentration of Aitken mode and accumulation mode in kiln head is obviously higher than that of kiln tail, coal mill and crushing. The difference between maximum values was about 1-2 orders of magnitude. The common characteristics of the number concentration distribution in the kiln head, kiln tail, coal mill and crushing was that the number of coarse particles mode is very small in size distribution spectrum of PM
10. The emission factors of kiln end, kiln head, coal mill, crushing and cement mill was 0.156 clinker g/t, 3.914 clinker g/t, 1.538 coal g/t, 0.016 stone g/t and 0.056 cement g/t respectively, the total amount of PM
2.5 emission was 207.48, 5205.62, 286.38, 28.73 and 131.50 t respectively, and the total amount of PM
2.5 emission from stationary sources was 5859.7 t. The research showed that the particle emission characteristics from different stationary sources in cement enterprises was larger difference and the particle emission was also different even if the same property stationary sources and the same kind of production process because of the different operating parameters of the enterprises, the stationary sources dust removal facilities, the particle detection methods and the instruments.