Abstract
Pulp suspension flow is characterized by a complicated relationship between fiber flocculation and turbulence intensity. The object of this study is to clarify the influences of duct construction on the flow, and to develop a high-consistency paper-forming headbox. Optical measurements were carried out to investigate the extent of dispersion in the pulp suspension flow in a duct having various turbulence generating elements. The results are as follows : (1) Both dispersion and reflocculation were remarkable in the duct flow with an orifice which is a strong turbulence generator. (2) The saw-blade-type duct flow indicated a higher dispersion rate and mild reflocculation, and therefore is suitable as the element of a paper machine headbox. (3) The power spectra of the flocculation signal suggest that the dispersion and reflocculation of a suspension is related to the turbulence scale characterized by the flowing duct dimension.
