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Kinetics of sulfur dioxide-alcohol-water (SAW) pulping of su

Kinetics of sulfur dioxide-alcohol-water (SAW) pulping of sugarcane straw (SCS), TAPPI JOURNAL June 2017

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.

Real Measurements Lead to Real Understandings and Better Operating Control of the Recovery Liquor Cycle, 2023 PEERS Conference

How to use total dissolved solids measurements to evaluate the performance of diffuser washers—A mill study, TAPPI Journal April 2020

ABSTRACT: Various types of pulp washing equipment are available. Each washing device has a unique mechanical construction, and the washing principle is often a combination of dilution, thickening, and displacement washing. In this work, the performance of the pressure diffuser washer is studied. In stepwise trials, the effect of the feed and discharge consistencies on the performance of the diffuser was studied. The effect of the downward velocity of the screen on the pressure diffuser’s washing efficiency was also studied. The measurement of total dissolved solids (TDS) by a process refractometer was used as a wash loss measurement unit and the refractometer’s results were used in the calculations of standardized Nordén efficiency (E10) values. The chemical oxygen demand (COD) and conductivity values were also measured and their results compared to the TDS results.The results indicated that feed consistency has a significant effect on the performance and effectiveness of the diffuser washers in the mill. It can also be stated that when the downward velocity of the screen is adjusted to too high a level, the washing efficiency of the pressure diffuser decreases. As a conclusion from the mill tests, it can be stated that even small process parameter changes can provide enhanced diffuser washing at the beginning of the washing line, which has a direct effect on the performance of post-oxygen washing.

Developing LignoBoost for the end user lignin quality requir

Developing LignoBoost for the end user lignin quality requirements, 2017PEERS

Evaluation of Acid Stage and of Hydrogen Peroxide on Alkalin

Evaluation of Acid Stage and of Hydrogen Peroxide on Alkaline Extraction of Eucalyptus Kraft Pulp, 2017PEERS

Process Evaluation for Sustainability Using TAPPI TIP 0404-63, TAPPICon25

Impact of Kraft Mill Chemistry on Economics: A Model-Based Approach to Optimizing Mill Profitability, 19PEERS

Impact of Kraft Mill Chemistry on Economics: A Model-Based Approach to Optimizing Mill Profitability, 19PEERS

Fluff Pulp Performance Improved by Alternative Pine Species, 19PEERS

Fluff Pulp Performance Improved by Alternative Pine Species, 19PEERS

Review of the Economics, Technologies and Products in the Non-wood Sector, 19PEERS

Review of the Economics, Technologies and Products in the Non-wood Sector, 19PEERS