scholarly journals Use of Taguchi Methods for Hierarchy of Influence Factors in the Application of Carbonitration in a Fluidized Bed Steel for 41Cr4 Steel

2021 ◽  
Vol 44 (3) ◽  
pp. 36-47
Author(s):  
Nelu CAZACU
Keyword(s):  
Fluidized Bed ◽  
Influence Factors ◽  
Taguchi Methods ◽  
Metallographic Analysis ◽  
Optimal Regime ◽  
Ammonia Gas ◽  
Number Of Factors ◽  
Granular Solid ◽  
Working Procedure ◽  
Hierarchy Of Influence

The work is based on carbonitriding in a fluidized layer with methane and ammonia gas applied to 41Cr4 steel samples. To achieve the best possible results, other factors must be taken into account, than those specific to carbonitring. It was necessary to use a partially factorial working procedure due to the increase in the number of factors. An A18 matrix has been used, with 18 lines of experiments in which three levels have been modified for 6 factors. The objective function was fixed at the final hardness after carbonitriding, hardening and tempering. The carbonitriding was performed in fluidized bed with granular solid ground and sorted to 0.1- to 0.16mm, and brought to fluidization with a mixture of methane and ammonia. The hardening has been done directly after carbonitriding in the fluidized bed. The experiments have been performed according to Taguchi Methods and the results indicate an optimal regime and the influence of the factors considered on the hardness after the thermo-chemical treatment and the thermal treatment. Metallographic analysis has been performed on the carbonitrided layer.

Influence Factors of Denitration Study on Catalyst Mn-Ce/TiO2

2013 ◽  
Vol 634-638 ◽  
pp. 526-530
Author(s):  
Chun Xiang Geng ◽  
Qian Qian Chai ◽  
Wei Yao ◽  
Chen Long Wang
Keyword(s):  
Reaction Temperature ◽  
Catalytic Reduction ◽  
Removal Rate ◽  
Load Capacity ◽  
Fixed Bed ◽  
Influence Factors ◽  
Space Velocity ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Ammonia Gas

Selective Catalytic Reduction (SCR) processes have been one of the most widely used denitration methods at present and the property of low tempreture catalyst becomes a hot research. The Mn-Ce/TiO2 catalyst was prepared by incipient impregnation method. The influence of load capacity, reaction temperature, O2 content, etc. on denitration were studied by a fixed bed catalyst reactor with ammonia gas. Results showed that catalyst with load capacity 18% performed high NO removal rate of 90% at conditions of reaction temperature 160°C, low space velocity, NH3/NO molar ratio 1: 1, O2 concentration 6%.

Chip Rebonding in Dry Turning of Nickel Based Alloys

2009 ◽  
Author(s):  
Jae-Wook Oh ◽  
Hsin-Yu Kuo ◽  
Kevin Meyer ◽  
Roger Lindle ◽  
Howard Weaver ◽  
...  
Keyword(s):  
High Speed ◽  
Cutting Speed ◽  
Taguchi Methods ◽  
Influential Factor ◽  
Metallographic Analysis ◽  
Dry Cutting ◽  
Workpiece Material ◽  
Screening Design ◽  
Machined Parts ◽  
On Chip

At some cutting conditions chips formed during high-speed face turning of nickel based alloys are re-bonded to the machined workpiece surface, even when coolant is applied. Unfortunately, chip-rebonding reduces surface quality, which leads to a shorter fatigue lives for machined parts. Although several researchers have documented this phenomenon and its effects, the root causes of this phenomenon is currently unknown. In order to determine the root causes of chip rebonding, past test samples exhibiting chip rebonding were first analyzed. Metallographic analysis revealed that the chip rebonding material is the same as the workpiece material and that the bonding is mechanically driven. Next, screening design of experiments (DOE) were completed to reliably reproduce chip rebonding in dry cutting cases. Chip rebonding detection and severity were measured using multiple equally spaced surface roughness measurements (Rt parameter). In addition, in-process cutting forces and tool wear measurements were recorded and compared. Finally Taguchi methods were applied to identify the key variables their influence on chip-rebonding. In dry cutting tests it was found that decreasing feed-rate while cutting at a constant cutting speed is the most influential factor in obtaining chip rebonding. High-speed video revealed that at lower feed-rates the chip curls back to the surface of workpiece, while at higher feed-rates the chip flows away from the cutting region with minimal curl. Additional testing performed verifies this theory.

Experimental Study on Sticking Behavior of Fluidized Bed in Reduction Process

2012 ◽  
Vol 482-484 ◽  
pp. 1354-1357
Author(s):  
Xing Juan Wang ◽  
Ran Liu ◽  
Jue Fang
Keyword(s):  
Fluidized Bed ◽  
Theoretical Basis ◽  
Iron Ore ◽  
Influence Factors ◽  
Reduction Process ◽  
Reduction Temperature ◽  
Gas Velocity ◽  
Construction Costs ◽  
Iron Ore Reduction ◽  
Reduce Energy Consumption

It is a good way that the fluidized bed is used as a substitute for reduction shaft in Corex process. Which can reduce energy consumption, environmental pollution and construction costs further, and also improve the competitiveness of Corex and blast furnace. At present, the sticking problem is present in iron ore reduction process and interrupts the reduction process, it has become a major obstacle on the development of fluidized bed. In this paper, a visualization hot model of fluidized bed is introduced. The influence factors on sticking behavior were analyzed from reduction temperature, gas velocity, atmosphere, degree of metallization or reduction and property of iron ore, the research provided a strong theoretical basis for controlling the sticking.

The Carbonic Acid Reaction of Phosphogypsum Decomposition Slag in the Three-Phase Fluidized Ded

2012 ◽  
Vol 550-553 ◽  
pp. 2921-2926 ◽  
Author(s):  
Yu Hang Chen ◽  
Li Ping Ma ◽  
Ren Yang ◽  
Hang Zhang ◽  
Long Gui Xie ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Gas Flow ◽  
Carbonic Acid ◽  
Influence Factors ◽  
Fluidized Bed Reactor ◽  
Inhibitory Effect ◽  
Co2 Gas ◽  
Solid Ratio ◽  
Three Phase ◽  
Acid Reaction

Through the study on influence factors of the carbonic acid reaction of phosphogypsum decomposition slag in the three-phase fluidized bed, the effect of different factors on the transformation of CaS in the phosphogypsum decomposition slag was discussed. Experiments show that Increasing CO2 gas flow and extending reaction time have benefit for the transformation of CaS. The conversion rate of CaS was increased firstly and then tended to flatten with the increase of the liquid-solid ratio. The rise of reaction temperature has a weak inhibitory effect for the transformation of CaS. Comparing with tank reactor, three-phase fluidized bed reactor is more advantageous to the carbonic acid reaction of phosphogypsum decomposition slag.

Mechanism Study and Influence Factors Analysis of Desulphurization in Flue Gas Circulating Fluidized Bed

2005 ◽  
Author(s):  
Yi Zhao ◽  
Shuang-Chen Ma ◽  
Xiao-Jun Sun
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Circulating Fluidized Bed ◽  
Influence Factors ◽  
Gas Absorption ◽  
Mechanism Study ◽  
Factors Analysis ◽  
Study Results ◽  
Two Phases

At present Flue Gas Desulphurization by Circulating Fluidized Bed (CFB FGD) has been widely used to partly take the place of the Spray Dry Absorbers (SDA) due to its simple system, excellent performance, occupying less area, and less cost, etc. It has been considered internationally as one of the most promising FGD technologies. The mechanism of FGD in CFB is introduced in the paper. Based on the mass transfer theory of two-phases, the fundaments of absorption and adsorption in CFB are analyzed. The influence of particle attrition on mass transfer coefficient of liquid phase is analyzed in terms of the special phenomenon in CFB. The result indicates that abrasion is beneficial to completely utilization of absorbents and further absorption, and it also has an inconspicuously enhanced effect on mass transfer. Fine particle agglomeration is analyzed in the paper and the study results show that the main course of FGD in CFB is absorbing process. Based on the gas absorption, the key parameters that influence desulphurization efficiency are analyzed finally. Mechanism study and influence factors analysis of FGD in CFB could be provided as the references for improving desulphurization.

Philosophies and Decision Making in Parole Board Members

2020 ◽  
Vol 100 (5) ◽  
pp. 640-661 ◽  
Author(s):  
Ebony L. Ruhland
Keyword(s):  
Decision Making ◽  
Influence Factors ◽  
Board Members ◽  
Number Of Factors ◽  
Parole Board ◽  
Parole Boards

Parole boards have discretion to make prison release decisions by applying a number of factors. While prior research has identified factors that are important, little is known about how parole board members interpret the factors and the degree to which members’ characteristics affect decision making. Using board transcripts, this study explored: (1) how members’ philosophies influence factors used in release decisions and; (2) how board members define and frame factor meanings. The findings provide insights into decisions that may create release disparities.

scholarly journals Study on Accounting Organization: Options and Influence Factors

2018 ◽  
Vol 24 (2) ◽  
pp. 31-36
Author(s):  
Alina-Teodora Ciuhureanu
Keyword(s):  
Influence Factors ◽  
Business Environment ◽  
Economic Environment ◽  
Number Of Factors ◽  
Development Region ◽  
Factors Of Influence ◽  
Main Factors ◽  
The Way

Abstract In the current economic environment that characterizes the business environment in Romania, organizing and conducting accounting is a challenge. The option of effective accounting organization is a choice of management that needs to be carefully analyzed but which is also based on a number of factors of influence. Starting from these aspects, we propose to analyze the way in which accounting is organized within the economic entities, taking into account their category and field of activity. We also sought to identify the main factors that influenced the choice of a way of organizing accounting. The study was conducted on a sample of 301 economic entities in the Development Region 7 Center - Romania

Grey Correlation Analysis of Sensitive Factors of Concrete Structures Durability

2008 ◽  
Vol 400-402 ◽  
pp. 471-476
Author(s):  
Jian Xin Liu ◽  
Ben Liang Liang
Keyword(s):  
Correlation Analysis ◽  
Influence Factors ◽  
Concrete Structures ◽  
Traditional Methods ◽  
Grey Correlation ◽  
Number Of Factors ◽  
Durability Design ◽  
Grey Correlation Analysis ◽  
Correlation Analysis Method ◽  
Grey Correlation Theory

Concrete structures durability is affected by a number of factors which have different sensitivity. According to level of sensitivity classified the influence factors could promote concrete structures durability design. The disadvantage of traditional methods of sensitivity analysis in concrete structures durability is the larger number of samples. The grey correlation theory was used to analyze the degree of the sensitivity of the influence factors and comparison with traditional methods of calculation. The results show that the grey correlation analysis method could quantify the levels of the sensitive factors and with higher reliability. A new way to study the durability of concrete structures was provided.

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