The Effect of Permeability on Lignite Fly Ash Pneumatic Conveying System Design

2018 ◽  
Vol 69 (2) ◽  
pp. 341-345
Author(s):  
Nikola Karlicic ◽  
Aleksandar Jovovic ◽  
Dejan Radic ◽  
Marko Obradovic ◽  
Dusan Todorovic ◽  
...  
Keyword(s):  
Fly Ash ◽  
Thermal Power ◽  
Heterogeneous Materials ◽  
Flow Mode ◽  
Low Grade ◽  
Pneumatic Conveying ◽  
Long Distance ◽  
Lignite Fly Ash ◽  
Minimum Fluidizing Velocity ◽  
Conveying System

The aim of this experimental study was to evaluate the effect of permeability on the mode of flow that lignite fly ash will support in a pneumatic conveying pipeline. This research was initiated by recurring problems with the long distance and high capacity low grade lignite ash pneumatic conveying system at the 1200 MWe thermal power plant, such as clogging, unsteady flow mode, significant increase of velocity due to pressure drop and erosive wear of pipeline. Ash samples were taken during pneumatic conveying system clogging for further analysis. The experiment was limited to measuring parameters that provide data to determine minimum fluidizing velocity and permeability. The results showed very heterogeneous materials of group B by Geldart, what caused specific phenomenon during the experimental fluidization tests. Minimum fluidizing velocity for this kind of material is not authoritative for defining pneumatic conveying system, since extremely heterogeneous materials at this air speed will remain stationary or will convey very slow or with stoppage, and that required velocities are from 10 to 15 times higher than minimum fluidizing velocity. According to the results, this ash is the most suitable for dense phase pneumatic conveying.

scholarly journals Effect of Lignite Fly Ash on the Growth and Reproduction of Earthworm Eisenia fetida

2009 ◽  
Vol 6 (2) ◽  
pp. 511-517 ◽  
Author(s):  
S. Sarojini ◽  
S. Ananthakrishnasamy ◽  
G. Manimegala ◽  
M. Prakash ◽  
G. Gunasekaran
Keyword(s):  
Fly Ash ◽  
Eisenia Fetida ◽  
Power Plants ◽  
Thermal Power ◽  
Biological Properties ◽  
Cow Dung ◽  
Physical Chemical ◽  
Lignite Fly Ash ◽  
Agricultural Use ◽  
Growth And Reproduction

Fly ash is an amorphous ferroalumino silicate, an important solid waste around thermal power plants. It creates problems leading to environmental degradation due to improper utilization or disposal. However, fly ash is a useful ameliorant that may improve the physical, chemical and biological properties of soils and is a source of readily available plant macro and micronutrients when it is used with biosolids. Supply of nutrients from fly ash with biosolids may enhance their agricultural use. The growth and reproduction ofEisenia fetidawas studied during vermicomposting of fly ash with cowdung and pressmud in four different proportions (T1,T2,T3& T4) and one controli.e.,cow dung and pressmud alone. The growth, cocoon and hatchlings production were observed at the interval of 15 days over a period of 60 days. The maximum worm growth and reproduction was observed in bedding material alone. Next to that the T1was observed as the best mixture for vermiculture.

Study on the characteristics of dense-phase pneumatic conveying of fly ash in long distance

2008 ◽  
Author(s):  
Zongming Liu ◽  
Weilin Zhao ◽  
Xiansong Li ◽  
Hua Yi ◽  
Congling Bu
Keyword(s):  
Fly Ash ◽  
Pneumatic Conveying ◽  
Dense Phase ◽  
Long Distance

Influence of Fluidizing Velocity on Fluidized Powder Conveying in a Horizontal Rectangular Channel

2011 ◽  
Author(s):  
Koichiro Ogata ◽  
Tomoya Furukawa ◽  
Yusuke Yamamoto
Keyword(s):  
Particle Density ◽  
Rectangular Channel ◽  
Porous Membrane ◽  
Horizontal Channel ◽  
Solid Loading ◽  
Pneumatic Conveying ◽  
Bed Height ◽  
Loading Ratio ◽  
Minimum Fluidizing Velocity ◽  
Conveying System

This study experimentally investigated the high dense pneumatic conveying of glass beads in a horizontal rectangular channel using the fluidizing air. The powder used belongs to Geldart A particle, where the mean diameter is 53 μm, the particle density is 2523kg/m3 and the minimum fluidizing velocity is 4.329mm/s. The fluidized powder conveying system consists of a powder supply hopper, a horizontal rectangular channel at the side of hopper and a receiving tank. The powder was fluidized by air through the porous membrane at the bottom of hopper and horizontal channel. Then, this system could be transported the fluidized powder toward the horizontal direction. In this study, the mass of transported powder, the bed height of powder in a hopper and the supply air pressure were measured when the fluidizing velocities at the bottom of hopper and horizontal channel were changed. The mass of transported powder with the fluidizing air to the bottom of hopper multiplied rapidly when the fluidizing velocity at the bottom of horizontal channel was larger than the minimum fluidizing velocity. Therefore, the fluidizing air at the bottom of hopper and horizontal channel was important to obtain smooth powder conveying on this system. Also, the mass flow rate of powder and the solid loading ratio were estimated from the mass of transported powder against the elapsed time. As the result, the solid loading ratio has taken a one peak when the fluidizing velocity at the bottom of channel was larger than the minimum fluidizing velocity. It was found from the analyzed solid loading ratio that the high dense powder conveying was possible in this system.

scholarly journals An Experimental Modeling for Dense Phase Pneumatic Conveying Capability using Multiple Hole Orifice in Air Supply Line for Dry Ash

2019 ◽  
Vol 8 (6S) ◽  
pp. 850-855
Keyword(s):  
Power Plant ◽  
Thermal Power ◽  
High Volume ◽  
Maintenance Cost ◽  
Pneumatic Conveying ◽  
Simple Task ◽  
Supply Line ◽  
Air Supply ◽  
Pipe Line ◽  
Conveying System

Optimization of dry ash flow is an important aspect in the field of dry ash conveying system in power plant. Material pickup and conveying to desired distance at desired rate with minimum conveying medium (air) is a primarily requirement of any pneumatic conveying dry ash system. Though it looks simple task to determine parameters of conveying medium i.e. air flow but significant challenges poses while designing air parameters at Material pickup point and to maintain to convey desired throughput to conveying distance. In today’s prevalent designs / technology for pneumatic dry ash conveying system, it uses valve as controlling device in air supply system. But such system of using valve as controlling device has certain drawbacks like a) Malfunctioning of valve due to moisture & ash accumulation leading to system failure. b) Unstable operation due to high vibration and temperature Compressed air is used for instruments control purpose as well as a conveying medium. Air is a compressible gas which makes controlling difficult when specific parameters needed at certain location depending on the ash collection rate & accordingly distribution piping layout. At such locations, we need a device i.e orifice in place of valve for the same in order to achieve the desired result. In general most of system designed for two stages 1) Air storage to maintain desired air parameters passing through system. 2) In 2nd phase of pneumatic conveying air supply lines, we require fine controlling of air parameters for air supply to multiple points / ash hoppers (108 Nos). Air required in system operation is controlled by valves in prevalent designs but due to drawbacks of valve (malfunction, high initial cost and high maintenance cost of valves), orifice is one of the most commonly used element in flow regulation because of its simple structure, construction, easy installation and reliable performance (as no moving part) the orifice is increasingly adopted in air supply lines of dry ash pneumatic conveying system. The work present experimental investigation of dry ash pneumatic conveying system using multiple hole orifice in conveying air supply line to enhance flow uniformity and mass distribution downstream of manifolds or at pickup point of material as a distributors at Koradi Thermal Power Plant and result where compare with previous data and the study is extended for different parameters like conveying pressure and fluidizing pressure mean in particle size of dry ash, orifice numbers, thickness of orifice and place of orifice mounting along with corresponding loading ratio. A new approach of modeling on similar pipe line configuration since scaling is not required, it has provided better accuracy and approximation when the result was compared with experimental data. This method of online experimentation is aimed to address the partial filling of pipe's cross section by the dune of dry ash which requires high volume conveying air,

scholarly journals GEOCHEMICAL ANALYSIS OF KOSTOLAC POWER PLANT FLY ASH: WORKING AND LIVING ENVIRONMENT INFLUENCE ASPECT

2018 ◽  
Vol 8 (1) ◽  
pp. 15-20 ◽  
Author(s):  
DRAGAN ĐORĐEVIĆ ◽  
MAJA STANKOVIĆ ◽  
NENAD KRSTIĆ ◽  
VLADIMIR DIMITRIJEVIĆ ◽  
NEMANJA ANASTASIJEVIĆ ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Power Plants ◽  
Thermal Power ◽  
Living Environment ◽  
Geochemical Analysis ◽  
Mineralogical Analysis ◽  
Respiratory Problems ◽  
Lignite Fly Ash ◽  
Fractionation Procedure

The aim of this study is geochemical analysis of flying ash generated by the combustion of lignite in the Kostolac A and B thermal power plants. The fractionation procedure of fly ash samples was done firstly, and then stereomicroscopy, FTIR, SEM / EDS and ICP-OES analyzes. The contents of heavy metals V, Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb were determined. The results showed that the concentrations of the tested heavy metals are within the limits that are not harmful to the human health. However, the mineralogical analysis of the mentioned ash indicates that the present glass and other high-temperature mineralogical components can cause respiratory problems and disfunction of other organs of the inhabitants of Kostolac and the immediate surrounding. The tested fly ash, also, can be used as a material in various fields of industry (e.g. construction). Key words: lignite, fly ash, Kostolac, heavy metals.

Modelling and analysis of flow of powders through long pipelines

2020 ◽  
Vol 17 (5) ◽  
pp. 709-718
Author(s):  
Shijo J.S. ◽  
Niranjana Behera
Keyword(s):  
Experimental Data ◽  
Fly Ash ◽  
Pressure Drop ◽  
Friction Factor ◽  
Power Plants ◽  
Thermal Power ◽  
Powder Materials ◽  
Pneumatic Conveying ◽  
Content Type ◽  
Dimensional Parameters

Purpose The purpose of this paper is to focus on predicting the pressure drop in fluidized dense phase pneumatic conveying of fine particles through pipelines by modelling the solids friction factor in terms of non-dimensional parameters using experimental data of definite pipeline configuration. Finally, the model is to be tested for a different pipeline configuration. Design/methodology/approach Solids friction factor has been expressed in terms of certain non-dimensional parameters such as density ratio, solids loading ratio and mean particle diameter to pipe diameter ratio, and a certain number of coefficients and exponents. Experimental data of five conveying materials (two types of fly ash, two types of alumina and one type of cement meal) for a pipeline configuration of diameter 53 mm and length 173 m and another conveying material EPS dust for two pipeline configurations (69-mm diameter, 168-m long; 105-mm diameter, 168-m long) have been used to calculate the unknown coefficients or exponents of the mathematical model for solids friction factor. Findings The developed model gives the best results in predicting the pressure drop for the pipelines that are less than 173-m long, but the model shows a large error for the pipelines more than 173-m long. Research limitations/implications Current research will be helpful for the researchers to model the process of pneumatic conveying through long distances. Practical implications The method will be helpful in conveying powder materials through long distances in cement or brick industry, alumina industry. Social implications Fly ash piles over at the nearby places of thermal power plants. Pneumatic conveying is the best method for transporting the fly ash from the location of power plants to the nearby brick industries or cement industries. Originality/value Solid friction factor has been presented in terms of four non-dimensional parameters and evaluated the accuracy in predicting the pressure drop for two different pipeline configurations.

A Review on Utilization of Fly- Ash and Pond-Ash as a Partial Replacement of Cement in Concrete Mix Design

2018 ◽  
pp. 413-418
Author(s):  
Harshkumar Patel ◽  
Yogesh Patel
Keyword(s):  
Fly Ash ◽  
Electricity Generation ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Strength Test ◽  
Partial Replacement ◽  
Pond Ash ◽  
Research Activities ◽  
Ash Disposal

Now-a-days energy planners are aiming to increase the use of renewable energy sources and nuclear to meet the electricity generation. But till now coal-based power plants are the major source of electricity generation. Disadvantages of coal-based thermal power plants is disposal problem of fly ash and pond ash. It was earlier considered as a total waste and environmental hazard thus its use was limited, but now its useful properties have been known as raw material for various application in construction field. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 180 MT fly is produced and only around 45% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash and fly-ash as cement in concrete mixes. In this present study of concrete produced using fly ash, pond ash and OPC 53 grade will be carried. An attempt will be made to investigate characteristics of OPC concrete with combined fly ash and pond ash mixed concrete for Compressive Strength test, Split Tensile Strength test, Flexural Strength test and Durability tests. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement in concrete.

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