scholarly journals CONJUGATE HEAT TRANSFER IN THE PRODUCTION OF GLASS MICROSPHERES IN A GAS-FLAME REACTOR

2018 ◽  
Vol 62 (3) ◽  
pp. 353-363
Author(s):  
M. Yu. Liakh ◽  
A. V. Akulich ◽  
P. S. Grinchuk
Keyword(s):  
Flow Rate ◽  
Conjugate Heat Transfer ◽  
Gas Flow ◽  
Air Flow Rate ◽  
Gas Flow Rate ◽  
Operating Environment ◽  
Glass Microspheres ◽  
Flame Reactor ◽  
Differential Scanning Colorimetry ◽  
Gas Flame

A model for the process of glass microsphere production in a recuperative gas-flame reactor was proposed. Based on the described mathematical model of heating and motion of particles in a high-temperature gas stream, which takes into account conjugate heat exchange between the reactor’s operating environment and the recuperator, the appropriate processes were modeled and optimized by geometric and regime parameters. The particle location time in the reactor at a temperature above 1400 °С, which was determined by data of differential scanning colorimetry, was used as an optimized charac- С, which was determined by data of differential scanning colorimetry, was used as an optimized charac- , which was determined by data of differential scanning colorimetry, was used as an optimized characteristic.As a result of optimization calculations, the reactor parameters (diameter and height, natural gas flow rate, air flow rate in the recuperator) were found, as well as regime parameters (diameter and flow rate of glass particles), under which microspheres can be formed. The information obtained can be a basis for designing an effective gas-flame reactor for production of glass microspheres.

EFFECT OF FROTHER (MIBC) ADDITION ON THE CHARACTERISTICS OF MICROBUBBLES GENERATED BY AIR DISSOLVED NUCLEATION

2012 ◽  
Vol 1380 ◽  
Author(s):  
Estrella Martínez-Ramos ◽  
Roberto Pérez-Garibay ◽  
Jorge Rubio-Rojas
Keyword(s):  
Linear Relationship ◽  
Flow Rate ◽  
Gas Flow ◽  
Research Work ◽  
Experimental Results ◽  
Flow Density ◽  
Air Flow Rate ◽  
Gas Flow Rate ◽  
Bubble Sizes ◽  
Superficial Area

ABSTRACTAn identification of the characteristics of microbbubles dispersion is presented in this paper, when frother addition (MIBC) is modified in a biphasic system (air-water). Sauter diameter (d32), gas flow rate (Jg), superficial area flow density of the microbubbles (Sb) and air holdup (εg) are the measured variables in this research work. The studied frother additions were 0, 10 and 20 ppm. Similar to conventional bubble sizes, it was observed also, that air holdup increases with the air flow rate. The linear relationship between εg and Sb permits to conclude that superficial area flow density, a variable difficult to measure directly, may be estimated if air gas holdup is known. Furthermore, the experimental results showed that frother addition (MIBC) reduced the Sauter diameter, increasing all other variables.

Experiment Research on Air Flow Rate Measurement Using Tracer Gas Method

2011 ◽  
Vol 374-377 ◽  
pp. 520-523
Author(s):  
Xian Yang Zeng ◽  
Zuo He Chi ◽  
Ming Guang Zheng ◽  
Gong Gang Sun ◽  
Guang Xue Zhang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Internal Diameter ◽  
Sampling Point ◽  
Air Flow Rate ◽  
Gas Flow Rate ◽  
Flow Rate Measurement ◽  
Tracer Gas ◽  
Injection Point ◽  
Relative Errors

Experiment research on the air flow rate measurement using tracer gas method in a 300mm internal diameter and 90° elbow duct are presented, which CO and air are selected as tracer gas and gas stream. Results show that the relative errors between the flow rate measured by tracer gas method and turbine flowmeter are varied in the range of -2.15%~1.69% when the injection point is upstream of the elbow on 7D~13D (D is the internal diameter of the duct), and the sampling point is downstream of the elbow on 10D~14D. The further distances of the injection point and sampling point are apart, the less relative errors of the gas flow rate measured by tracer gas method and turbine flowmeter are made. The injection flow rate of tracer gas should be matched with the gas flow rate in the duct. It is a simple and effective method that gas flowmeter online calibration with tracer gas method on the large diameter industrial gas pipeline transportation.

How Dry Is Dry?

2018 ◽  
Author(s):  
C. Hartloper ◽  
K. K. Botros ◽  
V. Liu ◽  
G. Lalonde ◽  
J. Lu ◽  
...  
Keyword(s):  
Water Content ◽  
Flow Rate ◽  
Gas Flow ◽  
Dew Point ◽  
Mountainous Terrain ◽  
Drying Process ◽  
Air Flow Rate ◽  
Gas Flow Rate ◽  
Air Drying ◽  
Start Up

Air drying is used after dewatering to dry a pipeline or piping facility before commissioning it with natural gas. This process typically involves blowing dehydrated air through the pipe sections until they are determined to be suitably dry. The question addressed in this paper is: how dry is dry? A common metric used to judge the pipe section’s dryness is the drying air’s outlet water dew point. Typically, air drying continues until a suitably dry low water dew point, such as −40°C, is measured at the outlet of the pipeline or facility. However, there is currently a lack of understanding of how this final outlet water dew point relates to the remaining water and thus the subsequent start up of the pipeline or facility. If the outlet water dew point is higher than required, issues may arise upon start up; e.g., hydrates could form along the pipeline or at downstream facilities. Conversely, if the outlet water dew point is lower than required, unnecessary time would have been spent in drying, and hence higher cost. This paper advocates an approach to determine when air drying is complete that considers the start-up phase. The approach consists of two parts. In the first part, the air drying parameters (drying air flow rate, inlet water dew point, etc.) and the final outlet water dew point are used to quantify the volume and surface area of water remaining after the drying process is completed. In the second part, the evaporation of this water into the gas flowing through the pipeline/facility after commissioning and start up is modeled as a function of the gas flow rate, temperature, pressure and inlet water content. Then, the water content of the gas at the delivery points is calculated. This increase can then be evaluated in reference to the water content specifications at the delivery points. The approach is exemplified by a 31 km NPS 48 pipeline over a mountainous terrain.

SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

2017 ◽  
pp. 3-18 ◽  
Author(s):  
B.S. Soroka ◽  
V.V. Horupa
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Renewable Energy Sources ◽  
Combustion Process ◽  
Orifice Diameter ◽  
Firing Process ◽  
Gas Flow Rate ◽  
Gas Combustion ◽  
Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

On the Influence of Fluctuating Flow Rate Upon the Performance and Behaviour of Isothermal Reacting Systems

1998 ◽  
Vol 63 (6) ◽  
pp. 881-898
Author(s):  
Otakar Trnka ◽  
Miloslav Hartman
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Fluidized Bed Reactor ◽  
Computational Techniques ◽  
Continuous Stirred Tank Reactor ◽  
Gas Flow Rate ◽  
Solid Reaction ◽  
Continuous Stirred Tank ◽  
And Performance ◽  
Reacting Systems

Three simple computational techniques are proposed and employed to demonstrate the effect of fluctuating flow rate of feed on the behaviour and performance of an isothermal, continuous stirred tank reactor (CSTR). A fluidized bed reactor (FBR), in which a non-catalytic gas-solid reaction occurs, is also considered. The influence of amplitude and frequency of gas flow rate fluctuations on reactant concentrations at the exit of the CSTR is shown in four different situations.

scholarly journals Investigation on influences of loose gas on gas-solid flows in a circulating fluidized bed (CFB) reactor using full-loop numerical simulation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengju Huo ◽  
Xiaohong Li ◽  
Yang Liu ◽  
Haiying Qi
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Separation Efficiency ◽  
Circulation Rate ◽  
Solid Mass ◽  
Gas Flow Rate ◽  
Gas Leakage ◽  
Mass Circulation

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.

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