Recovery boiler sootblowers: History and technological advances

TAPPI Journal ◽  
2015 ◽  
Vol 14 (1) ◽  
pp. 51-60
Author(s):  
HONGHI TRAN ◽  
DANNY TANDRA
Keyword(s):  
Cfd Modeling ◽  
Computing Systems ◽  
The Past ◽  
Technological Advances ◽  
Recovery Boilers ◽  
Computational Fluid Dynamics Cfd ◽  
Recovery Boiler ◽  
Steam Parameters ◽  
Insight Into ◽  
Deposit Removal

Sootblowing technology used in recovery boilers originated from that used in coal-fired boilers. It started with manual cleaning with hand lancing and hand blowing, and evolved slowly into online sootblowing using retractable sootblowers. Since 1991, intensive research and development has focused on sootblowing jet fundamentals and deposit removal in recovery boilers. The results have provided much insight into sootblower jet hydrodynamics, how a sootblower jet interacts with tubes and deposits, and factors influencing its deposit removal efficiency, and have led to two important innovations: fully-expanded sootblower nozzles that are used in virtually all recovery boilers today, and the low pressure sootblowing technology that has been implemented in several new recovery boilers. The availability of powerful computing systems, superfast microprocessors and data acquisition systems, and versatile computational fluid dynamics (CFD) modeling capability in the past two decades has also contributed greatly to the advancement of sootblowing technology. High quality infrared inspection cameras have enabled mills to inspect the deposit buildup conditions in the boiler during operation, and helped identify problems with sootblower lance swinging and superheater platens and boiler bank tube vibrations. As the recovery boiler firing capacity and steam parameters have increased markedly in recent years, sootblowers have become larger and longer, and this can present a challenge in terms of both sootblower design and operation.

CFD-modeling for more precise operation of the kraft recovery boiler

TAPPI Journal ◽  
2012 ◽  
Vol 11 (11) ◽  
pp. 19-27 ◽  
Author(s):  
MARKUS ENGBLOM ◽  
PASI MIIKKULAINEN ◽  
ANDERS BRINK ◽  
MIKKO HUPA
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
The Other ◽  
Cfd Modeling ◽  
Furnace Temperature ◽  
Model Predictions ◽  
Boiler Operation ◽  
Computational Fluid Dynamics Cfd ◽  
Recovery Boiler ◽  
Temperature Asymmetry

During kraft recovery boiler operation, situations can be encountered where the furnace temperature is asymmetric when comparing one side of the furnace to the other (i.e., left vs. right). In this paper, computational fluid dynamics (CFD) modeling is applied to study furnace load and liquor spraying as causes for asymmetric furnace temperatures in a 4450 tons dry solids (TDS)/day kraft recovery boiler. The model predictions are compared against validation measurements. Decrease in furnace load is identified as the main cause of the temperature asymmetry. The simulations also suggest that, at decreased load, relatively small differences in the tilts of individual liquor sprays can increase the temperature asymmetry.

scholarly journals CFD-modeling of fume formation in kraft recovery boilers

TAPPI Journal ◽  
2013 ◽  
Vol 12 (3) ◽  
pp. 25-32 ◽  
Author(s):  
AINO LEPPÄNEN ◽  
ERKKI VÄLIMÄKI ◽  
ANTTI OKSANEN ◽  
HONGHI TRAN
Keyword(s):  
Field Measurements ◽  
Enrichment Factors ◽  
Cfd Modeling ◽  
Cfd Model ◽  
Metal Chemistry ◽  
Kraft Recovery Boilers ◽  
Recovery Boilers ◽  
Computational Fluid Dynamics Cfd ◽  
Potassium Enrichment ◽  
Particle Mass Concentration

A computational fluid dynamics (CFD) model was developed to simulate alkali metal chemistry and fume particle formation in a kraft recovery boiler. The modeling results were partially validated against previously obtained field measurements. The model provides information about fume composition, chlorine and potassium enrichment factors, and particle mass concentration at different locations in the boiler.

scholarly journals Sedimentation Tanks for Treating Rainwater: CFD Simulations and PIV Experiments

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7852
Author(s):  
Krystian Czernek ◽  
Marek Ochowiak ◽  
Daniel Janecki ◽  
Tomasz Zawilski ◽  
Leszek Dudek ◽  
...  
Keyword(s):  
Fine Particles ◽  
Flow Patterns ◽  
Cfd Modeling ◽  
Rotational Flow ◽  
Cfd Simulations ◽  
Image Velocimetry ◽  
Standard Design ◽  
Computational Fluid Dynamics Cfd ◽  
Settling Process ◽  
Insight Into

The removal of solids is the most important step when treating rainwater. The article evaluates two designs of sedimentation tanks that can be used for the continuous separation of fine particles from water: OS—standard sedimentation tanks, and OW—swirl sedimentation tanks. The tanks were studied by conducting computational fluid dynamics (CFD) modeling and particle image velocimetry (PIV) experiments. The settling process in sedimentation tank was carried out at varying operating flow rates. A tank with a modified structure was used for the tests, where water was supplied by a nozzle placed at an angle. This solution made it possible to obtain a rotational flow that transported the suspended particles towards its wall, where downward axial velocity resulted in the settling of particles. Based on the research, it was observed that the flow patterns showed inward flow at the bottom of the tank and an upward flow and the lifting of the settled particles near the hatch at the bottom. The presented experimental measurements provided detailed insight into flow patterns, and valuable calibration and verification data for further CFD modeling. Traditional PIV techniques are useful in the case of standard design, whereas CFD is invaluable for supporting this work and for investigating the design of novel sedimentation tanks.

Run for Your Life! Childhood Physical Activity Effects on Brain and Cognition

2017 ◽  
Vol 6 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Charles H. Hillman ◽  
Kirk I. Erickson ◽  
Bradley D. Hatfield
Keyword(s):  
Physical Activity ◽  
Brain Health ◽  
School Aged Children ◽  
The Past ◽  
Real World Application ◽  
Technological Advances ◽  
Childhood Physical Activity ◽  
Scholastic Performance ◽  
Near Future ◽  
Insight Into

The past two decades have uncovered the beneficial relation of physical activity and other health behaviors on brain and cognition, with the majority of data emerging from older adult populations. More recently, a similar research thread has emerged in school-aged children, which offers insight into the relation of physical activity to scholastic performance, providing a real-world application of the benefits observed in the laboratory. Technological advances have similarly furthered our understanding of physical activity effects on cognitive and brain health. Given this emerging body of work, this manuscript reviews the basic findings within the field, but more importantly suggests triggers or signals from the emerging literature that will shape the field in the near future. The overall goal of this body of research is to increase cognitive and brain health to promote effective functioning of individuals across the lifespan.

FM Verification for the 21 st Century

2008 ◽  
Vol 18 (1) ◽  
pp. 4-9 ◽  
Author(s):  
Leisha Eiten ◽  
Dawna Lewis
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Current Technology ◽  
The Past ◽  
Technological Advances ◽  
Children With Hearing Loss

Background: For children with hearing loss, the benefits of FM systems in overcoming deleterious effects of noise, distance, and reverberation have led to recommendations for use beyond classroom settings. It is important that audiologists who recommend and fit these devices understand the rationale and procedures underlying fitting and verification. Objectives: This article reviews previousguidelines for FM verification, addresses technological advances, and introduces verification procedures appropriate for current FM and hearing-aid technology. Methods: Previous guidelines for verification of FM systems are reviewed. Those recommendations that are appropriate for current technology are addressed, as are procedures that are no longer adequate for hearing aids and FM systems utilizing more complex processing than in the past. Technological advances are discussed, and an updated approach to FM verification is proposed. Conclusions: Approaches to verification andfitting of FM systems must keep pace with advances in hearing-aid and FM technology. The transparency approach addressed in this paper is recommended for verification of FM systems coupled to hearing aids.

Catholicism and Cosmopolitanism: the Confluence of Three Catholic Scholars and the Cosmopolitan Democrats on State Sovereignty and the Future of Global Governance

2016 ◽  
Vol 3 (2) ◽  
pp. 37-51
Author(s):  
Matthew Bagot
Keyword(s):  
Global Governance ◽  
State Sovereignty ◽  
Current Debate ◽  
Past Century ◽  
Jacques Maritain ◽  
The Past ◽  
Technological Advances ◽  
The Future ◽  
Cosmopolitan Democracy ◽  
Catholic Tradition

One of the central questions in international relations today is how we should conceive of state sovereignty. The notion of sovereignty—’supreme authority within a territory’, as Daniel Philpott defines it—emerged after the Treaty of Westphalia in 1648 as a result of which the late medieval crisis of pluralism was settled. But recent changes in the international order, such as technological advances that have spurred globalization and the emerging norm of the Responsibility to Protect, have cast the notion of sovereignty into an unclear light. The purpose of this paper is to contribute to the current debate regarding sovereignty by exploring two schools of thought on the matter: first, three Catholic scholars from the past century—Luigi Sturzo, Jacques Maritain, and John Courtney Murray, S.J.—taken as representative of Catholic tradition; second, a number of contemporary political theorists of cosmopolitan democracy. The paper argues that there is a confluence between the Catholic thinkers and the cosmopolitan democrats regarding their understanding of state sovereignty and that, taken together, the two schools have much to contribute not only to our current understanding of sovereignty, but also to the future of global governance.

A summary of beach nourishment in China: The past decade of practices

Shore & Beach ◽  
2020 ◽  
pp. 65-73
Author(s):  
Gen Liu ◽  
Feng Cai ◽  
Hongshuai Qi ◽  
Jianhui Liu ◽  
Gang Lei ◽  
...  
Keyword(s):  
Beach Nourishment ◽  
Developed Countries ◽  
Ecological Design ◽  
Optimized Design ◽  
Limited Information ◽  
Personal Communications ◽  
Design Considerations ◽  
The Past ◽  
Technological Advances ◽  
Urban Beaches

Beach nourishment has been widely used for beach protection around the world. However, there is limited information about beach nourishment in China. This study offers an overview of beach nourishment practices, status and technological advances in China, based on the literature, reports, and personal communications. The results demonstrate that beach nourishment has been recognized as an effective and environmentally friendly measure to combat coastal erosion and has been increasingly adopted in China, especially in the past decade. The unique characteristics of coastal China resulted in a difference in beach nourishment between China and Western developed countries in terms of the types, objectives, and shapes of beach nourishment. For the types of nourishments in China, there were approximately the same number of restored beaches and newly constructed beaches. For fill sediment, homogeneous fill and heterogeneous fill comprised 51.1% and 48.9% of projects, respectively. The objective of beach nourishment was mainly to promote coastal tourism, and the shape of nourished beaches was dominated by headland bays. This study also indicated that China has achieved a number of technological advances in beach nourishment, including methods of beach nourishment on severely eroded coasts and muddy coasts, an optimized design of drain pipes involved in urban beaches, and ecological design considerations. From the past decade of practices, four aspects were proposed as considerations for future nourishment: sand sources, technique advances, ecological effects, and management of beach nourishments.

Upcoming Drifts In Bio-Similars

2020 ◽  
Vol 15 ◽  
Author(s):  
Geeta Aggarwal ◽  
Manju Nagpal ◽  
Ameya Sharma ◽  
Vivek Puri ◽  
Gitika Arora Dhingra
Keyword(s):  
Metabolic Diseases ◽  
Market Competition ◽  
Current Status ◽  
Medicinal Products ◽  
The Past ◽  
Biologic Activity ◽  
Emerging Trends ◽  
Regulatory Guidelines ◽  
Food Drug Administration ◽  
Insight Into

Background: Biopharmaceuticals such as Biologic medicinal products have been in clinical use over the past three decades and have benefited towards the therapy of degenerative and critical metabolic diseases. It is forecasted that market of biologics will be going to increase at a rate of 20% per year, and by 2025, more than ˃ 50% of new drug approvals may be biological products. The increasing utilization of the biologics necessitates for cost control, especially for innovators products that have enjoyed a lengthy period of exclusive use. As the first wave of biopharmaceuticals is expired or set to expire, it has led to various opportunities for the expansion of bio-similars i.e. copied versions of original biologics with same biologic activity. Development of biosimilars is expected to promote market competition, meet worldwide demand, sustain the healthcare systems and maintain the incentives for innovation. Methods: Appraisal of published articles from peer reviewed journals, PubMed literature, latest news and guidelines from European Medicine Agency, US Food Drug Administration (FDA) and India are used to identify data for review. Results: Main insight into the quality requirements concerning biologics, current status of regulation of biosimilars and upcoming challenges lying ahead for the upgrading of marketing authorization of bio-similars has been incorporated. Compiled literature on therapeutic status, regulatory guidelines and the emerging trends and opportunities of biosimilars has been thoroughly stated. Conclusion: Updates on biosimilars will support to investigate the possible impact of bio-similars on healthcare market.

scholarly journals Computational Investigation of Inclusion Removal in the Steel-Refining Ladle Process

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1048
Author(s):  
Xipeng Guo ◽  
Joel Godinez ◽  
Nicholas J. Walla ◽  
Armin K. Silaen ◽  
Helmut Oltmann ◽  
...  
Keyword(s):  
Multiphase Flow ◽  
Porous Plug ◽  
Cfd Modeling ◽  
Balance Model ◽  
Computational Investigation ◽  
Inclusion Removal ◽  
Inclusion Interaction ◽  
Computational Fluid Dynamics Cfd ◽  
Steel Refining ◽  
Transient Multiphase Flow

In a steel-refining ladle, the properties of manufactured steel can be notably degraded due to the presence of excessive inclusions. Stirring via gas injection through a porous plug is often used as part of the steel-refining process to reduce these inclusions. In this paper, 3D computational fluid dynamics (CFD) modeling is used to analyze transient multiphase flow and inclusion removal in a gas-stirred ladle. The effects of gas stirring with bubble-inclusion interaction are analyzed using the Euler–Euler approach for multiphase flow modeling, while the effects of inclusions aggregation and removal are modeled via a population balance model (PBM).

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