Heat transfer and friction loss of flowing kenaf core non-wood pulp fibre suspensions to curb reject papers

The heat and momentum transfer of crop pulp fibre suspensions were studied in a single pipe heat exchanger test loop. The data were produced at the pre-selected temperature, concentrations, and a range of flow rates. It was found that at the low fibre concentrations, the magnitude of heat transfer coefficient was higher than those of water data at the corresponding experimental conditions. However, the values progressively decreased below the water data at higher concentrations. The heat transfer data were affected by the variation of fibre characteristics, such as fibre flexibility, fibre length, fibre mechanical and chemical treatment, and the pulping methods used to liberate the fibres. The reduction of heat transfer coefficient was obtained with the enhancement of fibre flexibility observed by previous researchers for wood pulp fibres. In the present study, the characteristics of fibres and paper are correlated with heat and momentum transfer of suspensions of the fibres. Deviations in fibre properties can be monitored from the measurement of heat transfer coefficient or frictional pressure loss, and they can be adjusted by altering the degree of fibre refining treatment. Thus, the papers made from the fibre suspensions via in-situ monitoring could be uniform, consistent, and remain within the product specification. This could curb the rejected papers and ultimately reduce production costs and energy consumption.