scholarly journals Flow and Mixing Behavior in a New Bottom Blown Copper Smelting Furnace

2019 ◽  
Vol 20 (22) ◽  
pp. 5757 ◽  
Author(s):  
Pin Shao ◽  
Lepeng Jiang

A mathematical model was developed to describe gas–liquid flow and mixing behavior in a new bottom blown oxygen copper smelting furnace, and the model validation was carried out through a water model experiment. The effects of different nozzle locations, nozzle numbers, and gas flow rates on the gas–liquid flow, gas total volume, and mixing efficiency were investigated. The results show that the gas–liquid two-phase flow and mixing time predicted by the present model agree well with the experimental data. When the nozzles are located near the center of the bath bottom, the gas total volume is larger, but the mixing efficiency is very low. With the increase of nozzle arrangement angle, the mixing time decreased. However, the excessive angle arrangement of nozzles exceeding 21° was found to be detrimental to the bubble residence time and mixing efficiency. With the increase in nozzle numbers from nine to 13, the gas total volume in the furnace increases, and the mixing efficiency does not change greatly. When the number of nozzles is further increased to 18, the mixing efficiency begins to decrease significantly. As the gas flow rate increases from 4.7 m3/h to 14.1 m3/h, the gas total volume in the furnace increases, and the mixing time is rapidly reduced from 314.5 s to 251.5 s. When the gas flow rate exceeds 18.8 m3/h, the gas total volume and mixing efficiency change little.

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 565 ◽  
Author(s):  
Hongliang Zhao ◽  
Tingting Lu ◽  
Pan Yin ◽  
Liangzhao Mu ◽  
Fengqin Liu

In this study, a water-model experiment and numerical simulation were carried out in a pilot ISASMELT furnace to study the factors affecting mixing time. The experimental results were compared to the simulation results to test the accuracy of the latter. To study the internal factors that affect the mixing time, the turbulent viscosity and flow field were calculated using simulation. In addition, following previous research, external factors that influence the mixing time including the depth of the submerged lance, lance diameter, gas flow rate, and the presence of a swirler were studied to investigate their effect on the flow regime. The results indicated that the mixing time is controlled by the turbulent viscosity and velocity vector. In addition, it was found that the lance diameter should not exceed 3.55 cm to maintain sufficient energy for stirring the bath. Finally, the optimal gas flow rate that offers the best mixing efficiency was found to be 50 Nm3/h.


2016 ◽  
Vol 859 ◽  
pp. 153-157
Author(s):  
Pao Chi Chen ◽  
Sheng Zhong Lin

This work uses a continuous bubble-column scrubber for the absorption of CO2 with a 5M MEA solution under a constant pH environment to explore the effect of the pH of the solution and gas-flow rate (Qg) on the removal efficiency (E), absorption rate (RA), overall mass-transfer coefficient (KGa), liquid flow rate (QL), gas-liquid flow ratio (γ), and scrubbing factors (φ). From the outlet CO2 concentration with a two-film model, E, RA, KGa, QL, γ, and φ can be simultaneously determined at the steady state. Depending on the operating conditions, the results show that E (80-97%), RA(2.91x10-4-10.0x10-4mol/s-L), KGa (0.09-0.48 1/s), QL(8.74-230.8mL/min), γ (0.19-5.39), and φ (0.031-0.74 mol/mol-L) are found to be comparable with other solvents. In addition, RA, KGa, E, and QL have been used to correlate with pH and Qg, respectively, with the results further explained.


Konversi ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Erlinda Ningsih ◽  
Abas Sato ◽  
Mochammad Alfan Nafiuddin ◽  
Wisnu Setyo Putranto

Abstract- One of the most widely used processes for CO2 gas removal is Absorption. Carbon dioxide is the result of the fuel combustion process which of the hazardous gases. The aim of this research is to determine the total mass transfer coefficient and analyze the effect of the absorbent flow rate of the absorbent solution with the promoter and the gas flow rate to the total mass transfer coefficient value. The variables consisted of liquid flow rate: 1, 2, 3, 4, 5 liter/min, gas flow rate: 15, 25, 30, 40, 50 liter/min and MSG concentration: 0%, 1%, 3% and 5% by weight. The solution of Pottasium Carbonate as absorbent with MSG promoter is flowed through top column and CO2 gas flowed from bottom packed column. Liquids were analyzed by titration and the gas output was analyzed by GC. From this research, it is found that the flow rate of gas and the liquid flow rate is directly proportional to the value of KGa. The liquid flow rate variable 5 liters / minute, gas flow rate 15 l / min obtained value of KGa 11,1102 at concentration of MSG 5%. Keywords:  Absorption, CO2,  K2CO3, MSG. 


1994 ◽  
Vol 29 (10-11) ◽  
pp. 231-241 ◽  
Author(s):  
H. T. Chang ◽  
B. E. Rittmann

This paper presents a unified model that inter-relates gas flow rate, liquid flow rate, and hold-ups of each of the liquid, gas, and solid phases in three-phase, fluidized-bed biofilm (TPFBB) process. It describes how carrier properties, biofilm properties, and gas and liquid flow velocities control the system dynamics, which ultimately will affect the density, thickness, and distribution of the biofilm. The paper describes the development of the mathematical model to correlate the effects of gas flow rate, liquid flow rate, solid concentration, and biofilm thickness and density. This knowledge is critically needed in light of the use of TPFBB processes in treating industrial wastewater, which often has high substrate concentration. For example, the proper design of the TPFBB process requires mathematical description of the cause-effect relationship between biofilm growth and fluidization.


Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 555 ◽  
Author(s):  
Luis E. Jardón-Pérez ◽  
Daniel R. González-Morales ◽  
Gerardo Trápaga ◽  
Carlos González-Rivera ◽  
Marco A. Ramírez-Argáez

In this work, the effects of equal (50%/50%) or differentiated (75%/25%) gas flow ratio, gas flow rate, and slag thickness on mixing time and open eye area were studied in a physical model of a gas stirred ladle with dual plugs separated by an angle of 180°. The effect of the variables under study was determined using a two-level factorial design. Particle image velocimetry (PIV) was used to establish, through the analysis of the flow patterns and turbulence kinetic energy contours, the effect of the studied variables on the hydrodynamics of the system. Results revealed that differentiated injection ratio significantly changes the flow structure and greatly influences the behavior of the system regarding mixing time and open eye area. The Pareto front of the optimized results on both mixing time and open eye area was obtained through a multi-objective optimization using a genetic algorithm (NSGA-II). The results are conclusive in that the ladle must be operated using differentiated flow ratio for optimal performance.


SPE Journal ◽  
2006 ◽  
Vol 11 (02) ◽  
pp. 199-205 ◽  
Author(s):  
David I. Atkinson ◽  
Oyvind Reksten ◽  
Gerald Smith ◽  
Helge Moe

Summary Dedicated wet-gas flowmeters are now commercially available for the measurement of gas and liquid flow rates and offer a more compact measurement solution than does the traditional separator approach. The interpretation models of traditional multiphase flowmeters emphasize the liquid rate measurements and have been used to well test and meter mostly liquid-rich flow streams. These models were not developed for the measurement of gas flow rates, particularly those of wet gas. A new interpretation is described that allows a traditional multiphase flowmeter to operate in a dual mode either as a multiphase meter or as a wet-gas meter in 90 to 100% gas. The new interpretation model was developed for a commercially available multiphase flowmeter consisting of a venturi and a dual-energy composition meter. This combination results in excellent predictions of the gas flow rate; the liquid rate prediction is made with acceptable accuracy and no additional measurements. The wet gas and low-liquid-volume-fraction interpretation model is described together with the multiphase flowmeter. Examples of applying this model to data collected on flow loops are presented, with comparison to reference flow rates. The data from the Sintef and NEL flow loops show an error (including the reference meter error) in the gas flow rate, better than ± 2% reading (95% confidence interval), at line conditions; the absolute error (including the reference meter error) in the measured total liquid flow rate at line conditions was better than ± 2 m3/h (< ± 300 B/D: 95% confidence interval). This new interpretation model offers a significant advance in the metering of wet-gas multiphase flows and yields the possibility of high accuracies to meet the needs of gas-well testing and production allocation applications without the use of separators. Introduction There has been considerable focus in recent years on the development of new flow-measurement techniques for application to surface well testing and flow-measurement allocation in multiphase conditions without separating the phases. This has resulted in new technology from the industry for both gas and oil production. Today, there are wet-gas flowmeters, dedicated to the metering of wet-gas flows, and multiphase meters, for the metering of multiphase liquid flows. The common approach to wet-gas measurement relates gas and liquid flows to a "pseudo-gas flow rate" calculated from the standard single-phase equations. This addresses the need for gas measurement in the presence of liquids and can be applied to a limit of liquid flow [or gas volume fraction, (GVF)], though the accuracy of this approach decreases with decreasing GVF. The accurate determination of liquid rates by wet-gas meters is restricted in range. The application and performance of multiphase meters has been well documented through technical papers and industry forums, and after several years of development is maturing (Scheers 2004). Some multiphase measurement techniques can perform better, and the meters provide a more compact solution, than the traditional separation approach. It is not surprising that the use of multiphase flowmeters has grown significantly, the worldwide number doubling in little over a 2-year period (Mehdizadeh et al. 2002). Multiphase-flowmeter interpretation emphasizes the liquid rate measurement, and the application of multiphase flowmeters has been predominantly for liquid-rich flow stream allocation and well testing.


1989 ◽  
Vol 8 (2) ◽  
pp. 63-68
Author(s):  
A. J. Rautenbach ◽  
G. Kornelius

Spray columns are widely used in industry as a gas-liquid contacting apparatus because of the advantages of a high transfer area per unit volume and the tow gas side resistance. For a large number of systems, mass transfer parameters are not available and an experimental determination for the system benzene/wash oil was therefore carried out. The experimental technique and design are described. The variation in mass transfer coefficient as function of gas flow rate, liquid flow rate and column height agrees with those published elsewhere.


Nowadays, CO2 as the product of fossil fuel combustions, is polluting the air and the human environment, and it causes global warming. To reduce the negative effect of CO2 presence, it should be removed from the air by capturing methods. Hollow fiber membrane contactor (HFMC) system is one of the most efficient method for CO2 capturing than the other feasible capturing methods. In the present paper an HFMC absorbing system has been simulated using COMSOL Multiphysics software and the effect of flow rates of gas and liquid on the amount of CO2 removal has been studied. Aqueous solution of Mono-ethanolamine (MEA) is entered as the absorbent liquid in the tubes, and CO2 is removed from the shell side by the diffusion phenomena by participating in the chemical reaction with MEA. The results show that the higher liquid flow rate the higher %CO2 removal from the inserted gas. Against this result, the percentage of CO2 removal decreases with increasing the gas flow rate as expected. Higher gas flow rate leads the gas velocity to higher values and less possibility of absorbing by the diffusion method. The rate of the CO2 removal variation with liquid flow rate is higher than the CO2 removal variation whit the gas flow rate.


Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 917
Author(s):  
Luis E. Jardón-Pérez ◽  
Carlos González-Rivera ◽  
Marco A. Ramirez-Argaez ◽  
Abhishek Dutta

Ladle refining plays a crucial role in the steelmaking process, in which a gas stream is bubbled through molten steel to improve the rate of removal of impurities and enhance the transport phenomena that occur in a metallurgical reactor. In this study, the effect of dual gas injection using equal (50%:50%) and differentiated (75%:25%) flows was studied through numerical modeling, using computational fluid dynamics (CFD). The effect of gas flow rate and slag thickness on mixing time and slag eye area were studied numerically and compared with the physical model. The numerical model agrees with the physical model, showing that for optimal performance the ladle must be operated using differentiated flows. Although the numerical model can predict well the hydrodynamic behavior (velocity and turbulent kinetic energy) of the ladle, there is a deviation from the experimental mixing time when using both equal and differentiated gas injection at a high gas flow rate and a high slag thickness. This is probably due to the insufficient capture of the velocity field near the water–oil (steel–slag) interface and slag emulsification by the numerical model, as well as the complicated nature of correctly simulating the interaction between both gas plumes.


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