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88may148
Comments on "Unified theory of the mechanical properties of paper and other H-bond-dominated solids-Part 1, TAPPI JOURNAL May 1988
Journal articles
The relationship between print mottle and coating structure, TAPPI JOURNAL May 1988 88MAY47
The relationship between print mottle and coating structure, TAPPI JOURNAL May 1988
Journal articles
Mill experience with gate-roll-coated papers, TAPPI JOURNAL May 1988 88MAY53
Mill experience with gate-roll-coated papers, TAPPI JOURNAL May 1988
Journal articles
Applying pilot coater results to mill practice, TAPPI JOURNAL May 1988 88MAY61
Applying pilot coater results to mill practice, TAPPI JOURNAL May 1988
Journal articles
Meeting the needs of the fast-growing, fast-changing pressure-sensitive label industry, TAPPI JOURNAL May 1988 88MAY78
Meeting the needs of the fast-growing, fast-changing pressure-sensitive label industry, TAPPI JOURNAL May 1988
Journal articles
Trim-removal systems, TAPPI JOURNAL May 1988 88MAY87
Trim-removal systems, TAPPI JOURNAL May 1988
Journal articles
Optimization of a swirl burner for pulverized-wood fuels, TAPPI JOURNAL May 1988 88MAY91
Optimization of a swirl burner for pulverized-wood fuels, TAPPI JOURNAL May 1988
Journal articles
On-line layer discrimination of multilayer materials, TAPPI JOURNAL May 1988 88MAY97
On-line layer discrimination of multilayer materials, TAPPI JOURNAL May 1988
Journal articles
Magazine articles
Numerical analysis of the impact of rotor and screen hole plate design on the performance of a vertical pulper, TAPPI Journal April 2025
ABSTRACT: The dissolving of mechanical pulp is one of the most important process steps in stock preparation, since pulping occurs at the very beginning of the papermaking process. Efficient mixing of the pulp in a short amount of time is essential to achieve high furnish volume flow rates. The design of the rotor, as well as the pulper vat and inserts, significantly affects the overall performance of the pulper, such as mixing efficiency and power demand. Using advanced numerical methods such as computational fluid dynamics (CFD) can accelerate the development process. The CFD simulations allow for detailed analysis of flow phenomena, making it possible to study a real-size machine numerically. This approach is particularly advantageous because it can reduce the need for timeconsuming and costly experiments associated with scaling up test rigs. In this study, we compared two different rotor designs utilized in a vertical pulper and evaluated the numerical results with experimental data. Rotor A is designed for low turbulence and low power demand, while rotor B is designed for high turbulence with high power demand. The CFD results showed good agreement with the experimental measurements. We investigated how the rotor design influences the free fluid surface and the mixing efficiency. Our study also highlights the differences in results depending on whether water or furnish is simulated, which exhibit Newtonian or, respectively, non-Newtonian fluid behavior. Additionally, a detailed numerical investigation of various screen hole plate designs revealed that the newly developed hole design significantly reduces pressure loss compared to a standard drilled hole. This outcome was consistent for both types of fluids investigated: water and furnish.