Solution Space Exploration of the Process Design for Continuous Casting of Steel

2016 ◽  
Author(s):  
Maryam Sabeghi ◽  
Rishabh Shukla ◽  
Janet K. Allen ◽  
Farrokh Mistree
Keyword(s):  
Continuous Casting ◽  
Performance Measures ◽  
Solution Space ◽  
Quality Parameters ◽  
Operating Conditions ◽  
Production Costs ◽  
Steel Mill ◽  
Casting Operation ◽  
Conflicting Objectives ◽  
Plant Trials

Continuous casting is the process of solidifying molten metal to produce different products such as billet, bloom, or slab. This process can be formulated mathematically in terms of conflicting objectives including productivity, yield, quality and production costs to satisfy sets of constraints such as oscillation mark depth, metallurgical length and center line segregation. The objectives are conflicting in the sense that, if the productivity is increased, there is a reduction in other performance measures. These performance specifications are greatly influenced by operating conditions such as casting speed, superheat, mold oscillation frequency, and secondary cooling conditions. The process of identifying the set points for the continuous casting operation is iterative and expensive. The uncertainties inherent in modeling the phenomena computationally behooves exploration of the solution space to determine the quality of the solution and gain insight. In this paper, a method to explore the solution space is introduced. The method includes weight sensitivity and constraint sensitivity analysis. This analysis allows a designer to ascertain to what extent the solution is insensitive to uncertainties inherent in the modeling of the decision problem. This is a crucial step towards determining robust solutions for performance measures. The utility of the method is illustrated in providing decision support for the continuous casting operation in presence of variability in the operating parameters and conflicting end requirements, such as productivity and quality parameters. This method can be instantiated for exploring the solution space for ladle, tundish, rolling and annealing and thereby facilitating the exploration of the solution space for critical unit operations associated with steel product manufacturing. This development has the potential to reduce the number of plant trials necessary to determine the set points for manufacturing a new product mix with a new grade of steel using the existing equipment in a steel mill. The focus in this paper is on the method and not the results per se.

An Approach to Robust Process Design for Continuous Casting of Slab

2014 ◽  
Author(s):  
Rishabh Shukla ◽  
Sharad Goyal ◽  
Amarendra K. Singh ◽  
Jitesh H. Panchal ◽  
Janet K. Allen ◽  
...  
Keyword(s):  
Decision Support ◽  
Continuous Casting ◽  
Integrated Design ◽  
Performance Measure ◽  
Operating Conditions ◽  
Production Costs ◽  
Production Cycle ◽  
Performance Parameters ◽  
Steel Manufacturing ◽  
Conflicting Objectives

Continuous casting is a crucial step in the production of a variety of steel products. Its performance is measured in terms of conflicting objectives including productivity, yield, quality and production costs. These are conflicting in the sense that, if the productivity is increased, there is a reduction in other performance parameters. These performance parameters are greatly influenced by operating conditions such as casting speed, superheat, mold oscillation frequency, and secondary cooling conditions. An optimized solution for continuous casting process can be obtained. However uncertainty in operating parameters which affects the performance of caster is rarely considered. Moreover, the solution obtained is optimal with respect to a particular performance measure and does not provide a balance between all. In this paper an integrated design framework has been developed based on metamodels and the compromise Decision Support Problem (cDSP). The framework developed deals with uncertainty and yields robust solutions for performance measures. Further, the design space for continuous casting has been explored for different scenarios to determine satisficing solutions. The utility of the framework has been illustrated for providing decision support when an existing configuration for continuous casting is unable to meet the requirements. This approach can be instantiated for other unit operations involved in steel manufacturing and then may be integrated to simulate the entire production cycle of steel manufacturing. This in turn will enable development of materials with specific properties and reduce the time and cost incurred in the development of new materials and their manufacturing.

Design Exploration for Determining the Set Points of Continuous Casting Operation: An Industrial Application

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Rishabh Shukla ◽  
Sharad Goyal ◽  
Amarendra K. Singh ◽  
Jitesh H. Panchal ◽  
Janet K. Allen ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Cost Effective ◽  
Computational Method ◽  
Production Costs ◽  
Unit Operation ◽  
Secondary Cooling ◽  
Product Mix ◽  
Conflicting Objectives ◽  
Light Weighting ◽  
Downstream Processes

To compete with other materials and/or contribute toward light-weighting of vehicles, newer grades of steel are continuously invented and experimented upon. Due to the costs and time involved in such developments, manufacture of new grades of steel at an industrial scale is difficult. We propose a method that is useful for steel manufacturers interested in producing a steel product mix with new grades of steels by predicting the required change in the operating set points of each unit operation in the manufacturing chain of products with the new grade of steel. Here, we demonstrate a method to determine the set points of one unit operation, continuous casting which is measured in terms of conflicting objectives including productivity, quality, and production costs. These parameters are sensitive to the operating set points of casting speed, superheat, mold oscillation frequency, and secondary cooling conditions. To ensure targeted performance and address the challenges of uncertainty and conflicting objectives, an integrated computational method based on surrogate models and the compromise decision support problem (cDSP) is presented. The method is used to explore the design space available for casting operations and determine operating set points to meet requirements imposed on the caster from subsequent downstream processes. This method is of value to the steel industry and enables the rapid and cost effective production of a product mix with a new grade of steel.

Measuring Congestion and Reliability Impacts of Safety Projects

2021 ◽  
pp. 036119812110067
Author(s):  
Simona Babiceanu ◽  
Sanhita Lahiri ◽  
Mena Lockwood
Keyword(s):  
Performance Measures ◽  
Positive Impact ◽  
Operating Conditions ◽  
Vehicle Miles Traveled ◽  
Data Set ◽  
Data Points ◽  
Practical Recommendations

This study uses a suite of performance measures that was developed by taking into consideration various aspects of congestion and reliability, to assess impacts of safety projects on congestion. Safety projects are necessary to help move Virginia’s roadways toward safer operation, but can contribute to congestion and unreliability during execution, and can affect operations after execution. However, safety projects are assessed primarily for safety improvements, not for congestion. This study identifies an appropriate suite of measures, and quantifies and compares the congestion and reliability impacts of safety projects on roadways for the periods before, during, and after project execution. The paper presents the performance measures, examines their sensitivity based on operating conditions, defines thresholds for congestion and reliability, and demonstrates the measures using a set of Virginia safety projects. The data set consists of 10 projects totalling 92 mi and more than 1M data points. The study found that, overall, safety projects tended to have a positive impact on congestion and reliability after completion, and the congestion variability measures were sensitive to the threshold of reliability. The study concludes with practical recommendations for primary measures that may be used to measure overall impacts of safety projects: percent vehicle miles traveled (VMT) reliable with a customized threshold for Virginia; percent VMT delayed; and time to travel 10 mi. However, caution should be used when applying the results directly to other situations, because of the limited number of projects used in the study.

Conduction Roaster for Accelerated Roasting of Peanut

2021 ◽  
Vol 58 (02) ◽  
pp. 112-123
Author(s):  
Rakesh Kumar Raigar ◽  
Hari Niwas Mishra
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Rotational Speed ◽  
Specific Energy Consumption ◽  
Quality Parameters ◽  
Operating Conditions ◽  
Moisture Loss ◽  
Optimum Operating ◽  
Small Scale ◽  
Roasting Temperature

Roasting is one of the thermo-mechanical operation in cereals and oilseeds processing. Low-capacity machine for mechanisation of roasting is necessary for small-scale processing. A conduction-type motorised rotary roaster (8 kg per batch) was designed and developed for roasting of peanuts. Performance of the roaster was evaluated in terms of moisture loss, scorched kernels, and specific energy consumption for accelerated roasting of peanut. The effects of different roasting conditions were studied to determine the optimum operating conditions of the roaster. Quality indices of peanuts as moisture loss (kg.kg-1), scorched kernel (%), and specific energy consumption (kWh.kg-1) were dependent on the operating conditions. The optimum value of moisture loss (0.041± 0.003 kg.kg-1), scorched kernel (0.93± 0.0.004 % ), and specific energy consumption (0.185 ± 0.005 kWh.kg-1) were obtained at roasting temperature of 170°C, roasting time of 15 min, and rotational speed of 20 rpm for roasting peanut. The roasting characteristics of peanut decreased linearly with increase in the temperature and time; and decrease in the rotational speed. The inferior quality parameters were observed at higher temperatures, speed and medium time of roasting. The study indicated optimum roasting temperature of peanut to be 170°C, and further increase in the process temperature had undesirable effects on roasted peanut quality due to high loss of moisture.

Competitiveness of Timber Floor Elements: An Assessment of Structural Properties, Production, Costs, and Carbon Emissions

2021 ◽  
Vol 71 (2) ◽  
pp. 111-123
Author(s):  
Sveinung Nesheim ◽  
Kjell Arne Malo ◽  
Nathalie Labonnote
Keyword(s):  
Carbon Emissions ◽  
Solution Space ◽  
Wood Products ◽  
Production Costs ◽  
Low Carbon ◽  
Labor Costs ◽  
International Consensus ◽  
Novel Approach ◽  
Manufactured Products ◽  
Product Specifications

Abstract As long-spanning timber floor elements attempt to achieve a meaningful market share, proof of serviceability continues to be a demanding task as international consensus remains unsettled. Initiatives to improve vibration levels are achievable, but a lack of confidence in the market is resulting in increases in margins for both manufacturers and contractors. State-of-the-art concrete alternatives are offered at less than half the price, and even though timber floors offer reduced completion costs and low carbon emissions, the market is continuously reserved. Cost reductions for timber floor elements to competitive levels must be pursued throughout the product details and in the stages of manufacturing. As new wood products are introduced to the market, solution space is increased to levels that demand computerized optimization models, which require accurate expenditure predictions. To meet this challenge, a method called item-driven activity-based consumption (IDABC) has been developed and presented in this study. The method establishes an accurate relationship between product specifications and overall resource consumption linked to finished manufactured products. In addition to production time, method outcomes include cost distributions, including labor costs, and carbon emissions for both accrued materials and production-line activities. A novel approach to resource estimation linked to assembly friendliness is also presented. IDABC has been applied to a timber component and assembly line operated by a major manufacturer in Norway and demonstrates good agreement with empirical data.

scholarly journals Improvement of operation of steam cushion system for sensible thermal energy storage

2019 ◽  
Vol 116 ◽  
pp. 00107
Author(s):  
Ryszard Zwierzchowski
Keyword(s):  
Heat Flux ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Energy Savings ◽  
Operating Conditions ◽  
Production Costs ◽  
Technical Solution ◽  
Atmospheric Air ◽  
Suction Pipe

The paper contains a method for improvement of operation of steam cushion system including its energy savings analyses, for a Thermal Energy Storage (TES) tank. Energy savings analyses were performed using operational data from selected Combined Heat and Power plants, which supply heat to large cities in Poland and are furnished with the TES. The role of the steam cushion system in the TES tank is to prevent the stored water against absorbing oxygen from atmospheric air. In the TES tank, which is a non-pressure tank, oxygen from atmospheric air could penetrate to the network water through the surge chamber and safety valves. The steam pressure under the roof is generated from technological steam injected under the roof. Energy savings in the steam cushion system are generated by using an appropriate technical solution for the upper orifice and suction pipe for circulation water, i.e., to make it movable through the use of pontoons. An isolating buffer layer is created at the top of the tank with very small convective and turbulent heat transport, which causes limited heat transfer from steam bed to the stored water in the tank. This results in heat flux of approximately 10% of the heat flux that occurs in the typical technical solution of the upper orifice and suction pipe for circulation water in the TES tank. This technology offers great opportunities to improve the operating conditions of District Heating System, cutting energy production costs and emissions of pollutants to the atmosphere.

scholarly journals Selection of C-Type Filters for Reactive Power Compensation and Filtration of Higher Harmonics Injected into the Transmission System by Arc Furnaces

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2330
Author(s):  
Andrzej Grzegorz Lange ◽  
Grzegorz Redlarski
Keyword(s):  
Reactive Power ◽  
Second Harmonic ◽  
Transmission System ◽  
Operating Conditions ◽  
Arc Furnace ◽  
Steel Mill ◽  
Nonlinear Loads ◽  
Higher Harmonics ◽  
Current Harmonics ◽  
Arc Furnaces

This article presents a method for selecting the elements of a C-type filter working with a conventional LC-type filter for compensating reactive power and filtering out higher harmonics generated by arc furnaces and ladle furnaces. The study was conducted in a steel mill supplied by a 110 kV transmission system, where higher harmonic currents and nonlinear loads were measured. A series of computer simulations were performed under various operating conditions, and an algorithm for selecting the parameters of a third-order C-type filter (for suppressing the second harmonic) and two second-order LC-type filters (for suppressing the third harmonic) was proposed. The filtering system was tested in an arc furnace with the highest rated power, and harmonics in the current spectrum were evaluated. The results of the measurements were used to analyze the effectiveness of the compensation system comprising two passive C-type and LC-type filters at different system configurations. C-type filters significantly influenced current harmonics. The influence of the changes in the number of arc furnace transformers on the true Root Mean Square (RMS) of the currents injected into the 110 kV transmission system and on the voltages of the 110 kV busbars was discussed.

A Chaotic Krill Herd Algorithm for Optimal Solution of the Economic Dispatch Problem

2017 ◽  
Vol 31 ◽  
pp. 155-168 ◽  
Author(s):  
Bachir Bentouati ◽  
Saliha Chettih ◽  
Ragab Abdel-Aziz El-Sehiemy
Keyword(s):  
Optimization Problem ◽  
Economic Dispatch ◽  
Optimal Solution ◽  
Operating Conditions ◽  
Krill Herd Algorithm ◽  
Krill Herd ◽  
Conflicting Objectives ◽  
Metaheuristic Search ◽  
Elitism Scheme ◽  
Planning And Operation

The aim of economic dispatch (ED) problem is to provide an efficient utilization of energy resources to produce economic and secure operating conditions for the planning and operation of a power system. ED is formed as a nonlinear optimization problem with conflicting objectives and subjected to both inequality and equality constraints. An efficient improvement of krill herd (KH) algorithm, a powerful metaheuristic method, has been introduced in this paper. The KH algorithm inspired by the Lagrangian and evolutionary behaviour of the krill people in nature, has been investigated to solve ED problem on 6, 13, 20 and 40 generating units. The proposed chaotic krill herd (CKH)) improvement is done by incorporating the chaos approach to KH algorithm for raising the global convergence speed and for enhancing its performance. The elitism scheme serves to save the best krill during the procedure when updating the krill. The results show clearly the superiority of CKH in searching for the best cost value results when compared with well-known metaheuristic search algorithms.

Life Prediction of Cutting Tool by the Workpiece Cutting Condition

2011 ◽  
Vol 223 ◽  
pp. 554-563 ◽  
Author(s):  
Noemia Gomes de Mattos de Mesquita ◽  
José Eduardo Ferreira de Oliveira ◽  
Arimatea Quaresma Ferraz
Keyword(s):  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Operating Conditions ◽  
Production Costs ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Workpiece Material ◽  
The Cost

Stops to exchange cutting tool, to set up again the tool in a turning operation with CNC or to measure the workpiece dimensions have direct influence on production. The premature removal of the cutting tool results in high cost of machining, since the parcel relating to the cost of the cutting tool increases. On the other hand the late exchange of cutting tool also increases the cost of production because getting parts out of the preset tolerances may require rework for its use, when it does not cause bigger problems such as breaking of cutting tools or the loss of the part. Therefore, the right time to exchange the tool should be well defined when wanted to minimize production costs. When the flank wear is the limiting tool life, the time predetermination that a cutting tool must be used for the machining occurs within the limits of tolerance can be done without difficulty. This paper aims to show how the life of the cutting tool can be calculated taking into account the cutting parameters (cutting speed, feed and depth of cut), workpiece material, power of the machine, the dimensional tolerance of the part, the finishing surface, the geometry of the cutting tool and operating conditions of the machine tool, once known the parameters of Taylor algebraic structure. These parameters were raised for the ABNT 1038 steel machined with cutting tools of hard metal.

Reverse Osmosis Technology for Wastewater Reuse

1991 ◽  
Vol 24 (9) ◽  
pp. 215-227 ◽  
Author(s):  
B. J. Mariñas
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Quality Parameters ◽  
Operating Conditions ◽  
Water Quality Parameters ◽  
Feed Water ◽  
Hydraulic Pressure ◽  
Predominant Component ◽  
Percent Removal

Reverse osmosis technology has a great potential in the field of wastewater reclamation. A reverse osmosis plant includes the following processes: (1) feed water microfiltration and chemical conditioning, (2) membrane treatment, (3) permeate aeration, neutralization and disinfection, and (4) concentrate (liquid residue) treatment and disposal. The performance of reverse osmosis membranes depends on operating conditions and water quality parameters. Permeate productivity and contaminant removals increase with applied hydraulic pressure. Water quality parameters such as concentration, composition and pH also affect contaminant removal efficiencies. For example, the treatment of a simulated wastewater containing 10 mg/L of nitrate with a commercial polyamide-type reverse osmosis membrane resulted in membrane permeates containing approximately 0.05 mg/L of nitrate (or 99.5 percent removal) when sodium chloride was the major dissolved solid present in the feed water, and 1 mg/L (or 90 percent removal) when sodium sulfate was the predominant component. The removals of weak electrolyte contaminants are affected by feed water pH. For example, the removal of boron by a cellulose acetate-type membrane was reported to be greater than 99 percent at a pH of approximately 11, and less than 30 percent at a pH of 7. The practice of pre-treatment processes such as microfiltration and chemical conditioning can minimize performance deterioration resulting from membrane fouling by inorganic precipitates, organic macromolecules and microorganisms (biofouling).

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