Selection Criteria for Plain and Segmented Finned Tubes for Heat Recovery Systems

1994 ◽  
Vol 116 (2) ◽  
pp. 406-410 ◽  
Author(s):  
D. R. Reid ◽  
J. Taborek
Keyword(s):  
High Frequency ◽  
Heat Recovery ◽  
Unit Area ◽  
Cost Effective ◽  
Operating Conditions ◽  
Finned Tubes ◽  
The Past ◽  
Welding Technology ◽  
Fin Design ◽  
Selection Of

Heat recovery heat exchangers with gas as one of the streams depend on the use of finned tubes to compensate for the inherently low gas heat transfer coefficient. Standard frequency welded “plain” fins were generally used in the past, until the high-frequency resistance welding technology permitted a cost-effective manufacture of “segmented” fins. The main advantage of this fin design (Fig. 1) is that it permits higher heat flux and hence smaller, lighter weight units for most operating conditions. While the criteria that dictate optimum design, such as compactness, weight, and cost per unit area favor the segmented fin design, a few other considerations such as fouling, ease of cleaning, and availability of dependable design methods have to be considered. This paper analyzes the performance parameters that affect the selection of either fin type.

scholarly journals Selection Criteria for Plain and Segmented Finned Tubes for Heat Recovery Systems

1993 ◽  
Author(s):  
Don R. Reid ◽  
Jerry Taborek
Keyword(s):  
High Frequency ◽  
Heat Recovery ◽  
Unit Area ◽  
Cost Effective ◽  
Operating Conditions ◽  
Finned Tubes ◽  
The Past ◽  
Welding Technology ◽  
Fin Design ◽  
Selection Of

Heat recovery heat exchangers with gas as one of the streams depend on the use of finned tubes to compensate for the inherently low gas heat transfer coefficient. Standard frequency welded “plain” fins were generally used in the past, until the high frequency resistance welding technology permitted a cost-effective manufacture of “segmented” fins. The main advantage of this fin design (Fig. 1) is that it permits higher heat flux and hence smaller, lighter weight units for most operating conditions. While the criteria which dictate optimum design, such as compactness, weight and cost per unit area favor the segmented fin design, a few other considerations such as fouling, ease of cleaning and availability of dependable design methods have to be considered. This paper analyzes the performance parameters which affect the selection of either fin type.

scholarly journals An Outlook of Drilling Technologies and Innovations: Present Status and Future Trends

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4499
Author(s):  
Catalin Teodoriu ◽  
Opeyemi Bello
Keyword(s):  
Oil And Gas ◽  
Academic Research ◽  
Cost Effective ◽  
Operational Performance ◽  
Great Effort ◽  
Technological Advancement ◽  
The Past ◽  
Drilling Operations ◽  
Drilling System ◽  
Selection Of

The present article analyzes the technological advancement and innovations related to drilling operations. It covers the review of currently proven and emerging technologies that could mitigate the drilling operational deficiencies and instabilities that could hinder operational performance activities and the economic part of drilling development with great effort to minimize their environmental footprint. Drilling system design and operations are among the major aspects and cost-effective endeavors of the oil and gas industries, which are therefore technology dependent. They are also considered to be among the most expensive operations in the world, as they require huge expenses daily. Drilling success, depending on prevalent conditions, is a function of several general factors. These include the selection of the best technologies and tools, procedural optimization, concrete problem-solving, accurate prediction, and rapid decision-making. Consequently, any sorts of tools or advanced technologies that can improve the time-efficient operational and economic performance of drilling activities are essential and demanded. The paper provides a review of available technologies and developmental innovations based on both company-based and academic research-enabled drilling solutions over the past 5 years in the field of drilling systems and technological design. The paper further highlighted potential technologies that could be tapped in from other industries and could possibly be adopted by pushing the conventional boundaries of drilling operations.

scholarly journals Assessment of Subsampling Strategies in Microspectroscopy of Environmental Microplastic Samples

2021 ◽  
Vol 8 ◽  
Author(s):  
Josef Brandt ◽  
Franziska Fischer ◽  
Elisavet Kanaki ◽  
Kristina Enders ◽  
Matthias Labrenz ◽  
...  
Keyword(s):  
Risk Assessment ◽  
High Frequency ◽  
Inhomogeneous Distribution ◽  
Accurate Analysis ◽  
Acceptable Error ◽  
Particle Measurements ◽  
The Past ◽  
Analysis Technique ◽  
Selection Of ◽  
Environmental Compartments

The analysis of environmental occurrence of microplastic (MP) particles has gained notable attention within the past decade. An effective risk assessment of MP litter requires elucidating sources of MP particles, their pathways of distribution and, ultimately, sinks. Therefore, sampling has to be done in high frequency, both spatially and temporally, resulting in a high number of samples to analyze. Microspectroscopy techniques, such as FTIR imaging or Raman particle measurements allow an accurate analysis of MP particles regarding their chemical classification and size. However, these methods are time-consuming, which gives motivation to establish subsampling protocols that require measuring less particles, while still obtaining reliable results. The challenge regarding the subsampling of environmental MP samples lies in the heterogeneity of MP types and the relatively low numbers of target particles. Herein, we present a comprehensive assessment of different proposed subsampling methods on a selection of real-world samples from different environmental compartments. The methods are analyzed and compared with respect to resulting MP count errors, which eventually allows giving recommendations for staying within acceptable error margins. Our results are based on measurements with Raman microspectroscopy, but are applicable to any other analysis technique. We show that the subsampling-errors are mainly due to statistical counting errors (i.e., extrapolation from low numbers) and only in edge cases additionally impacted by inhomogeneous distribution of particles on the filters. Keeping the subsampling-errors low can mainly be realized by increasing the fraction of MP particles in the samples.

Challenges in Characterization and Acceptance of Metal Matrix Composite “Carrier Plate” Material for Space Applications

2012 ◽  
Vol 710 ◽  
pp. 412-417
Author(s):  
A.K. Shah ◽  
M.H. Thaker ◽  
K.B. Vyas
Keyword(s):  
Thermal Management ◽  
Thermal Conduction ◽  
Cost Effective ◽  
Operating Conditions ◽  
Thermal Dissipation ◽  
Space Applications ◽  
New Family ◽  
Day By Day ◽  
Composite Carrier ◽  
Selection Of

In space applications, day by day, the electronic devices are becoming compact with increase in operating frequencies and high power requirements posing challenges in design and selection of materials for high thermal dissipation requirements. In order to achieve optimum performance from thermal management material, engineers have to focus on high reliable, cost effective alternatives. Such materials need to demonstrate excellent thermal conduction to minimize thermo-mechanical stress and fatigue due to operations like soldering, thermal cycling and severe operating conditions. The paper describes a new family of thermal management composite material called “SILVAR”.

Medical Literature Searches -How Many Bibliographic Databases are Needed for Sufficient Retrieval in Medical Topics?

1985 ◽  
Vol 24 (03) ◽  
pp. 163-165 ◽  
Author(s):  
K. John
Keyword(s):  
Medical Literature ◽  
Cost Effective ◽  
Medical Faculty ◽  
Bibliographic Databases ◽  
Literature Searches ◽  
Selection Of

SummaryAs many bibliographic services in medicine are offered, literature searches in eight databases at DIMDI were performed to find out which database is most important in medicine. The distribution of publications from members of the medical faculty of Frankfurt University was examined. No save prediction is possible as to which database will yield most articles. Overlapping from different databases is often rather low. The selection of an appropriate database mix for sufficient recall and in a cost-effective manner.is a task for an experienced searcher.

Integrated FAHP-VIKOR model for green supplier selection in a Nickle coating SME

2020 ◽  
pp. 133-139
Author(s):  
Sanatan Ratna ◽  
B Kumar
Keyword(s):  
Staff Training ◽  
Supplier Selection ◽  
Fuzzy Ahp ◽  
Research Work ◽  
Supplier Evaluation ◽  
Green Supplier Selection ◽  
The Past ◽  
Coating Industry ◽  
Sustainability Issue ◽  
Selection Of

In the past few decades, there has been lot of focus on the issue of sustainability. This has occurred due to the growing concerns related to climate change and the growing awareness about environmental concerns. Also, the competition at global level has led to the search for the most sustainable route in the industries. The current research work deals with the selection of green supplier in a Nickle coating industry based on certain weighted green attributes. For this purpose, a hybrid tool comprising of Fuzzy AHP (Fuzzy Analytical Hierarchy) and VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje) is used. The Fuzzy AHP is used for assigning proper weights to the selected criteria for supplier evaluation, while VIKOR is used for final supplier selection based on the weighted criteria. The three criterions for green supplier selection are, Ecological packaging, Corporate socio-environmental responsibility and Staff Training. The outcome of the integrated model may serve as a steppingstone to other SMEs in different sectors for selecting the most suitable supplier for addressing the sustainability issue.

Regulatory and sustainability initiatives lead to improved polyaminopolyamide epichlorohydrin (PAE) wet-strength resins and paper products

TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 519-532 ◽  
Author(s):  
Mark Crisp ◽  
Richard Riehle
Keyword(s):  
Health And Safety ◽  
Cost Effective ◽  
Worker Safety ◽  
Regulatory Requirements ◽  
Wet Strength ◽  
The Past ◽  
Consumer Safety ◽  
Federal Institute ◽  
Sustainability Initiatives ◽  
The Impact

Polyaminopolyamide-epichlorohydrin (PAE) resins are the predominant commercial products used to manufacture wet-strengthened paper products for grades requiring wet-strength permanence. Since their development in the late 1950s, the first generation (G1) resins have proven to be one of the most cost-effective technologies available to provide wet strength to paper. Throughout the past three decades, regulatory directives and sustainability initiatives from various organizations have driven the development of cleaner and safer PAE resins and paper products. Early efforts in this area focused on improving worker safety and reducing the impact of PAE resins on the environment. These efforts led to the development of resins containing significantly reduced levels of 1,3-dichloro-2-propanol (1,3-DCP) and 3-monochloropropane-1,2-diol (3-MCPD), potentially carcinogenic byproducts formed during the manufacturing process of PAE resins. As the levels of these byproducts decreased, the environmental, health, and safety (EH&S) profile of PAE resins and paper products improved. Recent initiatives from major retailers are focusing on product ingredient transparency and quality, thus encouraging the development of safer product formulations while maintaining performance. PAE resin research over the past 20 years has been directed toward regulatory requirements to improve consumer safety and minimize exposure to potentially carcinogenic materials found in various paper products. One of the best known regulatory requirements is the recommendations of the German Federal Institute for Risk Assessment (BfR), which defines the levels of 1,3-DCP and 3-MCPD that can be extracted by water from various food contact grades of paper. These criteria led to the development of third generation (G3) products that contain very low levels of 1,3-DCP (typically <10 parts per million in the as-received/delivered resin). This paper outlines the PAE resin chemical contributors to adsorbable organic halogens and 3-MCPD in paper and provides recommendations for the use of each PAE resin product generation (G1, G1.5, G2, G2.5, and G3).

CAD Of Anticorrosive Protection Of Steel Structures

2019 ◽  
pp. 18-23
Keyword(s):  
Protective Coating ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Cost Effective ◽  
Operating Conditions ◽  
Computational Tool ◽  
Protection Method ◽  
Cost Effective Method ◽  
The Cost ◽  
Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

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