Theoretical And Experimental Study On Particulate Density And Granularity Measurement Based On Mie Scattering Theory

Particulate measurement is one of multi-discipline and multi-fieldtechnologies. It is known that most solid substances exist in the form ofparticulate including the nature substances such as soil, silt, atmosphere dust,flour of grain and sucrose, as well as artificial substances such as powder coal,catalyst, cement, chemical fertilizer, pigment and drug. Therefore, thetechnology related to measuring particulate and its application has a wideapplication in many industrial fields such as environmental protection,petrochemicals, medicine, coal, ocean, water conservancy, metallurgy, buildingmaterials, geology and foodstuff, etc.Although there are various principles to test particulate density andgranularity at present, the optical method has the meaning of further research forits peculiar features.The main contents are as follows:In chapter 2 the author analyzes the typical characteristics of the interactionbetween particulate and optical, reviews some related literatures aboutparticulate measurement, and compares the common measuring techniques andmethods with the typical ones. The laser particulate measuring method based onMie Scattering Theory is introduced, too. In the chapter 3 some related physicalconcepts, formulas and meanings in Mie Scattering Theory are summarized andillustrated, which will lay a solid foundation for further calculation. To get thegranularity of particulate by testing the intensity of scattering light, it isnecessary to know the theory of particulate scattering, i.e. comparing thescattering figure. According to two functions of intensity distribution based onMie scattering, scattering coefficient and efficiency factor of granularity arecalculated and scattering figure of granularity is described in the chapter 4. Thetesting method and its principle featuring the laser retro-scattering are putforward. On the basis of experiment with optical sensor and home-madesimulation chimney, it is feasible that this method is effective in a certain densityrange when the granularity is less than 10μm. In the chapter 6, the project formeasuring the density of granularity is given. The measurement data ofparticulate granularity and the method of calibrating granularity by slope will beput into practice in one state owned enterprise.The innovations are as follows:1 After analyzing and calculating the relation between the intensity ofscatted light and the granularity,the project and measuring system are designed.The experiment results verify the correctness of the theoretical calculation. Theslope relation between the intensity of scatted light and the granularity is usedfirstly to calibrate the granularity.2 The project of retro-lens is put forward to measure granularity in theactual smoking tunnel, increasing the optical path and decreasing difficulty incollimation.3 According to theoretical analysis and simulation, the back scattedmeasurement project of granularity is given using optical-fiber-sensor. Thecorrectness and feasibility of theoretical calculation and practical applicationare verified.4 The Mie Scattering Theory is fully studied;scattering coefficient andefficient factor are calculated and simulated.