Amostragem de partículas dispersas em correntes gasosas confinadas

• Ano de defesa: 1998
• Autor(a) principal: Costa, Maria Angélica Martins
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Programa de Pós-Graduação em Engenharia Química; UEM; Maringá, PR; Departamento de Engenharia Química
• Palavras-chave em Português: Particulados diversos; Corrente gasosa em dutos; Amostragem; Poluentes particulados; Poluentes atmosféricos; Brasil.; Engenharias; Engenharia Química
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/3723

In this work it was studied the sampling techniques of dispersed particulates into gaseous stream which are flowing ducts. A sampling study was carried out in order to determine concentration of each size of particle and the respective emission rates. This study was took place in a circular PVC duct having 12m. long and 0,1524 m of diameter. A gaseous air stream was produced in the duct to transport dispersed particles. The dispersion of particles was made by adding to the duct stream another air stream coming from a dust feed/dispersor, which contained high particle concentration. This allowed obtaining a dust gas stream flowing in PVC duct where sampling was carried out. The dust dispersed in the duct were alunima and titanium dioxide powders, which have particle size below 10µm. The gas stream sampling was performed under quasi-isokinetic conditions using probes aligned inside the duct. A laser particle counter was on-line used to analyse the sampled particles. This particle counter allows determining particle concentration for several size ranges, which can be used to estimate emission rates and efficiency of particle collection equipment. Velocities used to transport particles ranged from 11 to 36 m/s being the respective gas flow rate varied from 0,30 to 0,60 m3/s. From the concentration of particles by number, measured by the counter for 6 sizes ranges, it was possible to calculate the mass concentration of particles in the same ranges, that is between 0.3 and 10µm. Local concentration obtain in the duct are analysed according to the quasi-isokinetic conditions used in the sampling procedure. Total concentrations, which are representative of the cross sectional duct area, were determined for several gas flow rate in which particles were dispersed. These concentrations allowed estimating eventual emission rate of PM10 to the atmosphere. Obtained results indicate the feasibility of the particle counter to be used in duct sampling, particularly at low particle concentration. The reason for this is based on reliable obtained results in comparison to gravimetric methods which are time consuming, tedious to determine particle concentration and emission rates