Turbulence Calculations of a Dual-Structure Oxygen Lance for Converter Based on Hydrodynamics

The oxygen lance is a piece of special equipment in the converter steelmaking process for blowing oxygen into the molten steel. After more than 80 years of development, the structure and function of the oxygen lance have undergone many changes. In this paper, based on the theory of hydrodynamics, the jet behavior characteristics of a dual-structure oxygen lance for the converter are determined and optimized by CFD simulations and compared with those of the traditional-structure oxygen lance. The research results show that multiple jets deflect to the central axis of the oxygen lance during movement and the inclination angle of the nozzle holes influences the jet deflection. A decrease in the nozzle hole angle results in an increase in the mutual suction between the streams. With the increasing flow rate through the large holes in the new dual-structure oxygen lance, the dynamic radial pressure increases at the middle of the jet. The jet flow characteristics of the new dual-structure oxygen lance are better than those of the traditional oxygen lance. Its impact on the molten pool includes greater momentum, a larger impact area, and a more uniform and powerful stirring of the molten pool. A nozzle angle of 14° combined with a flow rate ratio of 65% and a nozzle angle of 17° combined with a flow rate ratio of 35% are the optimal parameters for the new dual-structure oxygen lance.

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Determination of flow rate ratio for plate valve operating in two-phase medium

Chemical and Petroleum Engineering ◽

10.1007/bf01156186 ◽

1989 ◽

Vol 25 (7) ◽

pp. 394-396

Author(s):

V. E. Shcherba ◽

I. S. Berezin ◽

S. S. Danilenko ◽

I. E. Titov ◽

P. P. Filippov

Keyword(s):

Flow Rate ◽

Rate Ratio ◽

Flow Rate Ratio ◽

Two Phase ◽

Plate Valve ◽

Phase Medium

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Effect of the argon/monomer flow-rate ratio on the flowability trend of PECVD-processed micropowder

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2017.08.063 ◽

2017 ◽

Vol 328 ◽

pp. 480-487 ◽

Cited By ~ 1

Author(s):

V.R. Giampietro ◽

M. Gulas ◽

P. Rudolf von Rohr

Keyword(s):

Flow Rate ◽

Rate Ratio ◽

Flow Rate Ratio

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Minimal flow rate ratio of slurry and gas in lime/limestone flue gas scrubbing technology

Wärme- und Stoffübertragung ◽

10.1007/bf01589973 ◽

1992 ◽

Vol 27 (1) ◽

pp. 11-15

Author(s):

H. Voos ◽

E. Kuciel ◽

R. Kubisa

Keyword(s):

Flow Rate ◽

Flue Gas ◽

Rate Ratio ◽

Flow Rate Ratio ◽

Minimal Flow ◽

Minimal Flow Rate

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Effects of Respiration and Gravity on Infradiaphragmatic Venous Flow in Normal and Fontan Patients

Circulation ◽

10.1161/circ.102.suppl_3.iii-148 ◽

2000 ◽

Vol 102 (suppl_3) ◽

Author(s):

Tain-Yen Hsia ◽

Sachin Khambadkone ◽

Andrew N. Redington ◽

Francesco Migliavacca ◽

John E. Deanfield ◽

...

Keyword(s):

Flow Rate ◽

Rate Ratio ◽

Venous Return ◽

Fontan Circulation ◽

Flow Rate Ratio ◽

Venous Flow ◽

Beneficial Effects ◽

In Series ◽

Expiratory Flow ◽

Fontan Patients

Background —In the Fontan circulation, pulmonary and systemic vascular resistances are in series. The implications of this unique arrangement on infradiaphragmatic venous physiology are poorly understood. Methods and Results —We studied the effects of respiration and gravity on infradiaphragmatic venous flows in 20 normal healthy volunteers (control) and 48 Fontan patients (atriopulmonary connection [APC] n=15, total cavopulmonary connection [TCPC] n=30). Hepatic venous (HV), subhepatic inferior vena caval (IVC), and portal venous (PV) flow rates were measured with Doppler ultrasonography during inspiration and expiration in both the supine and upright positions. The inspiratory-to-expiratory flow rate ratio was calculated to reflect the effect of respiration, and the supine-to-upright flow rate ratio was calculated to assess the effect of gravity. HV flow depended heavily on inspiration in TCPC compared with both control and APC subjects (inspiratory-to-expiratory flow rate ratio 3.4, 1.7, and 1.6, respectively; P <0.0001). Normal PV flow was higher in expiration, but this effect was lost in TCPC and APC patients (inspiratory-to-expiratory flow rate ratio 0.8, 1.0, and 1.1, respectively; P =0.01). The respiratory influence on IVC flow was the same in all groups. Gravity decreased HV flow more in APC than in TCPC patients (supine-to-upright flow rate ratio 3.2 versus 2.1, respectively; P <0.04) but reduced PV flow equally in all groups. Conclusions —Gravity and respiration have important influences on infradiaphragmatic venous return in Fontan patients. Although gravity exerts a significant detrimental effect on lower body venous return, which is more marked in APC than in TCPC patients, the beneficial effects of respiration in TCPC patients are mediated primarily by an increase in HV flow. These effects may have important short- and long-term implications for the hemodynamics of the Fontan circulation.

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Numerical and experimental investigation on the depressurization capacity of a new type of depressure-dominated jet mill bit

Petroleum Science ◽

10.1007/s12182-020-00472-8 ◽

2020 ◽

Vol 17 (6) ◽

pp. 1602-1615

Author(s):

Xu-Yue Chen ◽

Tong Cao ◽

Kai-An Yu ◽

De-Li Gao ◽

Jin Yang ◽

...

Keyword(s):

Flow Rate ◽

Rate Ratio ◽

Area Ratio ◽

Low Flow ◽

Flow Rate Ratio ◽

Cuttings Transport ◽

Horizontal Drilling ◽

Hole Cleaning ◽

Bottom Hole ◽

New Type

AbstractEfficient cuttings transport and improving rate of penetration (ROP) are two major challenges in horizontal drilling and extended reach drilling. A type of jet mill bit (JMB) may provide an opportunity to catch the two birds with one stone: not only enhancing cuttings transport efficiency but also improving ROP by depressuring at the bottom hole. In this paper, the JMB is further improved and a new type of depressure-dominated JMB is presented; meanwhile, the depressurization capacity of the depressure-dominated JMB is investigated by numerical simulation and experiment. The numerical study shows that low flow-rate ratio helps to enhance the depressurization capacity of the depressure-dominated JMB; for both depressurization and bottom hole cleaning concern, the flow-rate ratio is suggested to be set at approximately 1:1. With all other parameter values being constant, lower dimensionless nozzle-to-throat-area ratio may result in higher depressurization capacity and better bottom hole cleaning, and the optimal dimensionless nozzle-to-throat-area ratio is at approximately 0.15. Experiments also indicate that reducing the dimensionless flow-rate ratio may help to increase the depressurization capacity of the depressure-dominated JMB. This work provides drilling engineers with a promising tool to improve ROP.

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The Characteristics of CH4-Vapor Catalytic Reforming Reaction Considering CO2 and CH4 Reaction in the Micro-Chamber

ASME 5th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2007-30143 ◽

2007 ◽

Author(s):

Jing-Yu Ran ◽

Li-Xiang Niu ◽

Qiang Tang ◽

Li Zhang

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Rate Ratio ◽

Reaction System ◽

Conversion Ratio ◽

Flow Rate Ratio ◽

Ni Catalyst ◽

Complex Reaction ◽

Catalytic Reforming

Methane and vapor catalytic-reaction is a complex reaction system, and especially CH4/CO2 reaction has an important influence to the methane/vapor reforming reaction. In this paper, the reaction character for methane and vapor catalytic reforming reaction in the micro-chamber wall with Ni catalyst is numerically investigated. The results show that the CH4/CO2 reaction has a vital influence on reactive characteristics in the different H2O/CH4 mole ratio and the mass flow-rate. With increasing the H2O/CH4 mole ratio, the concentration of H2 and CO2 increases, the concentration of CO increases and then decreases, but if the H2O/CH4 mole ratio is more than 2.5, the result is different. The reaction efficiency will descend while the flow-rate increases. The results also display that the methane conversion ratio, the vapor conversion ratio, and the hydrogen concentrations can be up to 81.73%, 69.42%, and 4.29%, while the H2O/CH4 mole ratio, flow-rate and methane/vapor mass flow-rate ratio are 2.5, 7 g/h and 0.1 respectively.

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Effect of CS2 Flow Rate on the Formation of Aligned Carbon Microcoils

Materials Science Forum ◽

10.4028/www.scientific.net/msf.947.40 ◽

2019 ◽

Vol 947 ◽

pp. 40-46

Author(s):

Hyun Ji Kim ◽

Sung Hoon Kim

Keyword(s):

Flow Rate ◽

Vapor Deposition ◽

Rate Ratio ◽

Chemical Vapor ◽

Regular Structure ◽

Flow Rate Ratio ◽

Total Flow ◽

Total Flow Rate ◽

Flow Rates ◽

Thermal Chemical Vapor Deposition

The formation of aligned carbon microcoils could be achieved using C2H2 as a source gas and CS2 as an incorporated additive gas under thermal chemical vapor deposition system. To elucidate the ratio of C2H2/CS2 for the formation of the aligned carbon microcoils, the CS2 flow rate was first manipulated under the identical C2H2 flow rate (500sccm) condition. The formation and the alignment of carbon microcoils could be only achieved under the ratio of C2H2/CS2 = 33.3 condition, namely the flow rates of CS2 = 15sccm and C2H2= 500sccm. The total flow rate of the used gases was varied under the identical C2H2/CS2 flow rate ratio (33.3) condition. The C2H2 flow rate was manipulated under the identical CS2 flow rate (15sccm) condition. It was found that the formation and the alignment of carbon microcoils could be only achieved under the condition of 15sccm of CS2 flow rate in the range of 200 ~ 500sccm of C2H2 flow rate, regardless of the flow rate ratio of C2H2/CS2 and the total flow rate. The crystal structure of the well-aligned CMCs reveals the increase in the (002) peak in XRD spectrum for the aligned carbon microcoils, indicating the existence of the more regular structure in the aligned carbon microcoils. Based on these results, the cause for the formation of the aligned carbon microcoils only in the case of the CS2 flow rate = 15sccm with the imaginary pictures for the flow rate ratio of C2H2/CS2 just above the substrate were proposed.

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Factors Influencing Hardness of a Coating Material for Coating a Machine Component

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.821.294 ◽

2019 ◽

Vol 821 ◽

pp. 294-300

Author(s):

Charnnarong Saikaew

Keyword(s):

Wear Resistance ◽

Flow Rate ◽

Rate Ratio ◽

Flow Rate Ratio ◽

Machine Component ◽

Operating Pressure ◽

Operating Condition ◽

Significant Process ◽

Process Factors ◽

Dc Current

This work investigated the influences of DC current, pressure and N2 to Ar gas flow rate on hardness of a TiN hard coating material for coating a fishing net-weaving machine component of a fishing net-weaving machine, namely upper hook. The target of this study was to maximize the hardness of TiN coated upper hook in order to maximize the corresponding wear resistance. Three process factors including DC current, operating pressure and N2 to Ar flow rate ratio were simultaneously investigated using the factorial design with replicates at the center point of the three factors method. Analysis of variance was used to investigate the effect of the three factors on the hardness of the TiN coated upper hook and the contour plots based on empirical model were plotted to obtain an appropriate operating condition of the statistically significant process factors with maximizing hardness value leading to the wear resistance of the upper hook. The results showed that the operating pressure and the N2 to Ar flow rate ratio and interaction among the three process factors significantly affected the average hardness at the level of significance of 0.05. Finally, an appropriate operating condition of the significant process factors was obtained at the higher levels of the operating pressure and the N2 to Ar flow rate ratio.

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Experimental Investigation of Effusion Cooling Performance on the Liner of a Scaled Three Injector Annular Combustor

Volume 5B: Heat Transfer ◽

10.1115/gt2016-57035 ◽

2016 ◽

Cited By ~ 2

Author(s):

Yongbin Ji ◽

Bing Ge ◽

Shusheng Zang ◽

Jiangpeng Yu ◽

Ji Zhang

Keyword(s):

Flow Rate ◽

Rate Ratio ◽

Equivalence Ratio ◽

Swirl Flow ◽

Main Flow ◽

Flow Rate Ratio ◽

Cooling Effectiveness ◽

Cooling Performance ◽

Swirl Flows ◽

Annular Combustor

Gas turbine combustors design nowadays is aimed at achieving extremely lower NOx emissions through involving more air into the combustor to perform lean combustion, which results in the reduction of cooling air ratio for the liner walls. In this context, effusion cooling, one of the most effective cooling strategies, is adopted on the liner for its advantages of providing well cooling protection with limited amount of air. The swirl flow structure generated by the injector to stabilize flame in most modern lean-burn combustor is very complex with recirculation and vortex breakdown. So the interaction between three dimensional main flow and jets issued from the effusion holes is significant when assessing effusion cooling performance on the liner. In the present work, detailed effusion cooling feature on both inner and outer liners of a scaled annular combustor equipped with three axial swirlers has been provided under non-reactive and reactive conditions. The main flow is electrically heated for the non-reactive condition, while premixed combustion is realized after methane is fueled into the injectors and mixed with the air in the surrounding passage for the reactive condition. Temperature distribution on the target bended plate with 7 rows of discrete cooling holes in an in-line layout is captured by infrared thermography, and the cooling effectiveness is then analyzed. Effects of coolant to mainstream flow rate ratio and equivalence ratio are evaluated respectively. Results show that the macro rotational flow generated by the swirl flows interacts with cooling film and leads to non-symmetric cooling protection circumferentially on both liners. Additionally, averaged cooling effectiveness is found to increase with the flow rate ratio. At reactive conditions, stagnation of the high temperature swirl flow impinging on the liner wall locates at X/D range of 0.4–0.5, which has not been observed at non-reactive conditions. Also cooling effectiveness results indicate that outer liner obtains better cooling protection than inner liner when reaction is activated. Finally, the effect of most interested parameter for combustion process equivalence ratio is surveyed at Φ=0.7, 0.8 and 0.9. With experimental results, the importance of the combustion is highlighted in weighing the effusion cooling performance on the real annular combustor liners, which can’t be predicted comprehensively by non-reactive investigations. To obtain more knowledge of this issue, future work concerned with the flow field and flame visualization needs to be done through experimental techniques and numerical methods.

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