3 documents found, page 1 of 1
Heterogeneous studies in pulping of wood: Modelling mass transfer of alkali
Simão, João P. F.; Egas, Ana P. V.; Carvalho, M. Graça; Baptista, Cristina M. S. G.; Castro, José Almiro A. M.In this paper a heterogeneous lumped parameter model is proposed to describe the mass transfer of effective alkali during the kraft pulping of wood. This model, based on the spatial mean of the concentration profile of effective alkali along the chip thickness, enables the estimation of the effective diffusion coefficient that characterizes the internal resistance to mass transfer and the contribution of the ex...
Efeito da secagem no potencial papeleiro de pastas Kraft de eucalipto : uma exp...
Carvalho, M. Graça; Fernandes, João R.; Ferreira, Luís A.; Van Zeller, Carlos A.; Ferreira, João Pinho; Ferreira, Paulo J.
A comparative study of two automated techniques for measuring fiber length
Carvalho, M. Graça; Ferreira, Paulo J.; Martins, Alexandre A.; Figueiredo, M. MargaridaMeasurements from two automated fiber analyzers—Kajaani FS-200 and Galai CIS-100—are compared.The FS-200 measures fiber length and coarseness via an indirect optical method.The CIS-100 measures fiber length and width by analyzing video images of fibers. Length-weighted average fiber lengths for the FS-200 were 10–20% lower than those for the CIS-100. Reference measurements from microscopic image analysis sugges...