Search

Experimental study and prediction of two-phase flow pattern distribution diagrams in multi-channel cylinder dryer, TAPPI Journal July 2023

ABSTRACT: The multi-channel cylinder dryer (MCD) is designed to improve heat transfer. Although there are numerous research studies on the pressure drop, heat transfer characteristics, and flow pattern in static state of MCD, there is little research on the flow pattern in the rotating state. In this paper, the distribution of flow pattern in MCD under different rotating speeds and steam mass flow rates is studied. Furthermore, the logistic regression method (LR) is used to predict the flow pattern diagrams. The results show that in the front section of the flow channel, the flow pattern is basically annular flow, which is not affected by mass flow rate and rotating speed. On the other hand, wavy flow, vortex flow, slug flow, and bubble flow can be observed when the fluid enters the middle and the end section. The higher the rotating speed and the steam mass flow rate, the more the flow pattern tends to be an annular and wavy flow. At the end of the passage, the flow pattern is mainly slug flow. The predicted flow pattern diagrams are in good agreement with the experimental result, and to obtain an effective flow pattern in the middle and the end section of the flow channel, the influence of increasing rotating speed is greater than that of increasing steam mass flow rate. However, the specific rotating speed, steam mass flow rate, and other parameters should still be set by combining with the actual situation. This work can provide some references for the further study of MCD flow characteristics.

A discrete element method to model coating layer mechanical properties with bimodal and pseudo-full particle size distributions, TAPPI Journal July 2023

ABSTRACT: The mechanical properties of paper coating layers are important in converting operations such as calendering, printing, and folding. While several experimental and theoretical studies have advanced our knowledge of these systems, a particle level understanding of issues like crack-at-the-fold are lacking.A discrete element method (DEM) model is used to describe bending and tension deformations of a coating layer. The particles in the model are either bimodal distributions or pseudo-full particle size distributions of spherical particles. The impact of particle size distribution on the predicted mechanical properties of the coating layer is reported. Inputs to the model include properties of the binder film and the binder concentration. The model predicts crack formation as a function of these parameters and also calculates the modulus, the maximum stress, and the strain-to-failure. The simulation results are compared to previous experimental results. Reasonable predictions were obtained for both tensile and bending for a range of latex-starch ratios and at various binder concentrations. The influence of particle packing density on mechanical properties is reported.

Over the Wire, Paper360º July/August 2023

Maximizing Capital Equipment: Practical Advice for Boxmakers, Paper360º July/August 2023

Featured Case Study: Corrugated Machine Cuts Start-up Time in Half, Paper360º July/August 2023

Committees Offer Technical Engagement for Corrugated Professionals, Paper360º July/August 2023

The Paper360° 2023 TOP 50 POWER LIST, Paper360º July/August 2023

Corra’s Journey, Part 4: The Creaser/Slotter Section, Paper360º July/August 2023

R&M FAULT ZONE SERIES:, Paper360º July/August 2023

Digital Transformation Can Help Balance Sustainability, Profitability, Paper360º July/August 2023