dc.contributorAguiar, Mônica Lopes
dc.contributorhttp://lattes.cnpq.br/0431688649128529
dc.contributorhttp://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4779200E2
dc.creatorFelicetti, Marcos Alceu
dc.date.accessioned2004-09-22
dc.date.accessioned2016-06-02T19:56:33Z
dc.date.available2004-09-22
dc.date.available2016-06-02T19:56:33Z
dc.date.created2004-09-22
dc.date.created2016-06-02T19:56:33Z
dc.date.issued2004-03-31
dc.identifierFELICETTI, Marcos Alceu. Determinação da força de adesão entre partículas e uma superfície aplicando a técnica centrífuga.. 2004. 174 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2004.
dc.identifierhttps://repositorio.ufscar.br/handle/ufscar/4008
dc.description.abstractThe present work is dedicated to the investigation of the influence of particles size of the powdery material on the adhesion force of particle-substrate, using the centrifugal technique for different compression speeds and detachment. A centrifuge (MA - 860, Marconi Equipamentos), with maximum speed of rotation 14000 rpm, was used in the adhesion experiments and also a program of analysis of images (Image-Pro Plus 3.0). For the experiments development, two tubes were specially builded and installed in the headstock of the centrifuge. Inside of those tubes there are two adapters placed with the purpose to stand the proof disks containing the powdery material. The centrifugal force speed is generated to promote the compression (Press-on) or the detachment (Spin-off) of the particles on the surface of the disks. After the count of the particles initially stuck on the surface, the disks were returned back in the centrifuge to proceed the detachment of the particles, using different rotation speeds. After each increase of the rotational speed, the number of particles stuck on the surface of the disks is monitored. The centrifugal speed will exceed above of the adhesion force between the particle and the surface. At equilibrium, the magnitude of the centrifugal force applied equals the adhesion force. The influence of the applied forces in the adhesion of the phosphatic concentrate (ρ = 3,066 g/cm3 and dp = 14,91 µm), the manioc starch (ρ =1,491 g/cm3 and dp = 4,93 µm) and the dolomite limestone (ρ =2,838 g/cm3 and dp = 11,97 µm) on a substratum of stainless steel was investigated using the centrifugal technique. The range diameter studied for those particulate materials were of 10 - 17 µm, 17 - 24 µm and 24 - 31 µm. The particles of each powder were pressed initially on the surface of the substratum centrifuged to a private speed, and immediately after this phase, the adhesion profile was determined. All the powders obeyed a log-normal distribution of percentage of particles stuck in relation to adhesion force. It was obtained the force of geometric medium adhesion for all the powders and it was verified that there was a lineal increase with the force of compression applied initially. For polydisperse particles stuck on a surface, the necessary force to separate the particles varies proportionally to your size. And the adhesion force among particles of the three powdery materials, used in the experiments, and the surface of the disk of stainless steel increased with the increase of the size of the particles and with the increase of the compression force (press-on). the order of adherence indicated the following relationship: manioc starch > dolomite limestone > phosphatic concentrate.
dc.publisherUniversidade Federal de São Carlos
dc.publisherBR
dc.publisherUFSCar
dc.publisherPrograma de Pós-Graduação em Engenharia Química - PPGEQ
dc.rightsAcesso Aberto
dc.subjectAr - poluição
dc.subjectForça de adesão
dc.subjectVan der Waals, Força de
dc.subjectTécnica centrífuga
dc.subjectCompressão e descompressão de partículas
dc.titleDeterminação da força de adesão entre partículas e uma superfície aplicando a técnica centrífuga
dc.typeTesis


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