EFFECT OF COAL FLOW RATE AND BURNER LOCATION IN A PUSHER TYPE REHEATING FURNACE

2018 ◽  
Author(s):  
Saurav Chakraborty ◽  
Sajal Randhar ◽  
Abhimanyu Baruah ◽  
Prabal Talukdar
Keyword(s):  
Flow Rate ◽  
Reheating Furnace ◽  
Coal Flow

Modeling Pressurized Dense Phase Coal Fluidization and Transport

2019 ◽  
Author(s):  
Bradley R. Adams ◽  
Taylor L. Schroedter
Keyword(s):  
Flow Rate ◽  
Particle Interaction ◽  
Drop Out ◽  
Coal Bed ◽  
Flow Ratio ◽  
Feed System ◽  
Horizontal Pipe ◽  
Flow Rates ◽  
Coal Particles ◽  
Coal Flow

Abstract A transient gas-solid model based on CPFD Software’s Barracuda Virtual Reactor was developed for a feed system to a pilot-scale pressurized oxy-coal (POC) reactor. A simplified geometry with a vertical coal hopper feeding into a 0.635-cm diameter horizontal pipe was used to represent key elements of the feed system. Coal particles were transported with 20-atm CO2 gas. The feed system was required to maintain a steady flow of gas and solids at a coal flow rate of approximately 3.8 g/s and a CO2 to coal mass ratio in the range 1–2. Sensitivity of model results to mesh size and particle interaction sub-model settings was assessed. Two design concepts were evaluated. A gravity-fed concept was found to be infeasible due to inadequate coal flow rates even at very high CO2 to coal flow ratios. This was due to gravitational forces being insufficient to move the pressurized coal from the hopper into the CO2 stream at the desired rate. A fluidized bed concept was found to provide the desired coal flow rate and CO2 to coal flow ratio. CO2 injected at the hopper base first fluidized the vertical coal bed before transporting it through a horizontal exit pipe. A second CO2 inlet downstream of the hopper exit pipe was used to dilute the fluidized coal and increase pipe velocities to minimize coal drop out. The amount of coal transported from the hopper was dependent on the net CO2 hopper flow but independent of the CO2 dilution flow. This meant that the coal flow rate and CO2 to coal flow ratio could be controlled independently. Pipe exit coal flow rates were found to fluctuate at levels acceptable for steady burner operation.

Optimization of Heat Transfer Process in a Walking Beam Reheat Furnace Using Computational Fluid Dynamics

2018 ◽  
Author(s):  
Yuchao Chen ◽  
Armin K. Silaen ◽  
Nicholas Walla ◽  
Kurt Johnson ◽  
Chenn Q. Zhou
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Air Temperature ◽  
Flow Rate ◽  
Flame Length ◽  
Slab Surface ◽  
Gas Temperature ◽  
Reheating Furnace ◽  
Flame Angle

In the steelmaking process, reheating furnaces are used to reheat steel slabs to a target rolling temperature. The bottom intermediate zone inside the reheating furnace plays a decisive role in controlling the slab temperature distribution before slabs enter the soaking zone. Efforts to maintain a uniform slab surface temperature and thus enhance product quality require a good understanding of the furnace’s operation. However, traditional physical experiments are costly and have high risks as well. In this study, a three-dimensional steady-state computational fluid dynamics (CFD) model was developed to investigate the flow field in the bottom intermediate zone of a full-scale reheating furnace. The commercial software ANSYS Fluent® was used to solve the transport equations to predict the flame length, heat transfer, and gas temperature near the slab. Total input mass flow rate, preheated air temperature, and air/fuel ratio were selected to investigate the comprehensive influence of the furnace’s performance, which can be evaluated from the flame length, flame angle, and average gas temperature near the slab. Importantly, an orthogonal experimental design was conducted to optimize the evaluation factors by considering the multi influencing factors simultaneously. The simulation results indicate that a higher mass flow rate produces a lower upwards flame angle, which can prevent the hot spot detected on the slab surface. A higher preheated air temperature leads to a higher average gas temperature in this furnace; meanwhile, the flame becomes shorter by enhancing the air-fuel ratio.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE

1989 ◽  
Vol 47 ◽  
pp. 1000-1001
Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Succinic Anhydride ◽  
Volume Flow Rate ◽  
Mass Density ◽  
Uranyl Acetate ◽  
Volume Flow ◽  
Base Resin ◽  
And Performance ◽  
Acid Anhydrides

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.

Severe Drooling and Treatment With Botulinum Toxin

2012 ◽  
Vol 21 (1) ◽  
pp. 15-21
Author(s):  
Merete Bakke ◽  
Allan Bardow ◽  
Eigild Møller
Keyword(s):  
Botulinum Toxin ◽  
Side Effects ◽  
Health Risk ◽  
Flow Rate ◽  
Clinical Evidence ◽  
Acetylcholine Release ◽  
Psychosocial Problems ◽  
Rate Reduction ◽  
Local Inhibition ◽  
Surgical Treatments

Severe drooling is associated with discomfort and psychosocial problems and may constitute a health risk. A variety of different surgical and non-surgical treatments have been used to diminish drooling, some of them with little or uncertain effect and others more effective but irreversible or with side effects. Based on clinical evidence, injection with botulinum toxin (BTX) into the parotid and submandibular glands is a useful treatment option, because it is local, reversible, and with few side effects, although it has to be repeated. The mechanism of BTX is a local inhibition of acetylcholine release, which diminishes receptor-coupled secretion and results in a flow rate reduction of 25–50% for 2–7 months.

EFFECT OF BODY MASS INDEX ON PEAK EXPIRATORY FLOW RATE

2019 ◽  
Vol 3 (9) ◽  
Author(s):  
K. Subramanyam ◽  
Dr. P. Subhash Babu
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Peak Expiratory Flow ◽  
Flow Rate ◽  
Peak Expiratory Flow Rate ◽  
Normal Weight ◽  
The Body ◽  
Health Care Centre ◽  
Expiratory Flow ◽  
Group B

Obesity has become one of the major health issues in India. WHO defines obesity as “A condition with excessive fat accumulation in the body to the extent that the health and wellbeing are adversely affected”. Obesity results from a complex interaction of genetic, behavioral, environmental and socioeconomic factors causing an imbalance in energy production and expenditure. Peak expiratory flow rate is the maximum rate of airflow that can be generated during forced expiratory manoeuvre starting from total lung capacity. The simplicity of the method is its main advantage. It is measured by using a standard Wright Peak Flow Meter or mini Wright Meter. The aim of the study is to see the effect of body mass index on Peak Expiratory Flow Rate values in young adults. The place of a study was done tertiary health care centre, in India for the period of 6 months. Study was performed on 80 subjects age group 20 -30 years, categorised as normal weight BMI =18.5 -24.99 kg/m2 and overweight BMI =25-29.99 kg/m2. There were 40 normal weight BMI (Group A) and 40 over weight BMI (Group B). BMI affects PEFR. Increase in BMI decreases PEFR. Early identification of risk individuals prior to the onset of disease is imperative in our developing country. Keywords: BMI, PEFR.

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.

The standard unit mass flow rate of gas-liquid mixtures

2020 ◽  
pp. 13-16
Author(s):  
V.N. Petrov ◽  
◽  
V.F. Sopin ◽  
L.A. Akhmetzyanova ◽  
Ya.S. Petrova ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Liquid Mixtures ◽  
Unit Mass ◽  
Standard Unit
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