Effects of Some Wood Chip Properties on Pulp Quality
A series of TMP experiments were performed at CIPP’s TMP pilot plant, and some pulp properties were measured. By comparing chip and pulp properties, and using projections to latent structures (PLS) analysis, we were able to demonstrate that on-line CMS measurements can be used to predict some pulp properties. It should be pointed out that the focus of this paper is to show how CMS measurements can be used to predict some pulp properties. This prediction will suggest ways to control chip quality so as to ensure pulp quality. We tried to explain some important chip properties included in the measurements, but did not try to model them.
On-line chip analysis : new technology for an improved pulping process
ScanChip est un systeme en ligne d'analyse optique de mesure de la qualite des copeaux base sur leurs dimensions reelles. Les resultats, c'est a dire les differentes granulometries et les distributions en longueur, largeur et epaisseur des copeaux, sont disponibles sous forme numerique ou graphique. Ils peuvent etre visualises a l'ecran, imprimes sous forme de rapports, ou envoyes au systeme de controle existant de l'usine. Le systeme ScanChip fonctionne depuis 1992 dans une usine suedoise de pâte a papier, ou il est installe en aval du lessiveur continu. Cet emplacement permet que le systeme soit utilise pour emettre des alarmes au niveau de la qualite des copeaux, et un controle automatise des melanges de differents stocks de copeaux. D'autres positionnements du systeme permettent de mesurer la qualite des copeaux en sortie de dechiqueteuse ou celles des copeaux en provenance de fournisseurs. Un systeme d'analyse de ce type, qui procure instantanement des donnees sur la qualite des copeaux et achemine les resultats aux operateurs ou aux systemes de controle des procedes, peut aider a definir et controler la qualite des copeaux et les parametres des procedes de fabrication de la pâte et ainsi optimiser la production.
Effects of Equipment Dimensions on Liquid Mixing Time of Bubble Column with Draft Tube
The liquid mixing time of a bubble column with a draft tube is experimentally studied. The diameter and height of the column, the diameter and length of the draft tube, and the mode of sparging gas were changed and the liquid mixing time was measured.The lengths of bottom and top clearances have significant effects on the liquid mixing time. The liquid mixing time increases with increasing column aspect ratio of height to diameter. The liquid mixing time of the bubble column with a draft tube is longer than that of a standard bubble column when the column aspect ratio is relatively high. The liquid mixing time has a minimum when the diameter ratio of draft tube to column is 0.5 to 0.6. These effects of equipment dimensions are expressed by an equation. In the experiment using different solutions, the liquid mixing time becomes shorter with increasing liquid surface tension, or with increasing liquid viscosity.