Coal-Ash Composition as Related to High-Temperature Fireside Corrosion and Sulfur-Oxides Emission Control

1972 ◽  
Vol 94 (2) ◽  
pp. 142-148 ◽  
Author(s):  
R. W. Borio ◽  
R. P. Hensel
Keyword(s):  
High Temperature ◽  
Emission Control ◽  
Coal Ash ◽  
Sulfur Oxides ◽  
Fireside Corrosion ◽  
Ash Composition

Corrosion of Superheaters and Reheaters of Pulverized-Coal-Fired Boilers, II

1961 ◽  
Vol 83 (4) ◽  
pp. 468-474 ◽  
Author(s):  
Carl Cain ◽  
Wharton Nelson
Keyword(s):  
High Temperature ◽  
Liquid Phase ◽  
Gas Phase ◽  
Coal Ash ◽  
Pulverized Coal ◽  
Corrosion Mechanism ◽  
Fireside Corrosion ◽  
Factors Affecting ◽  
Ferritic Alloys ◽  
Tube Metal

This paper deals with studies of high-temperature fireside corrosion of reheater and superheater tubes in pulverized-coal-fired boilers. Factors affecting the temperature range and rate of corrosion by molten complex alkali sulfates are described. The influence of sulfides, produced by reaction of complex sulfates with tube metal, on corrosion rate is discussed. The similarity of coal-ash to oil-ash corrosion mechanism is brought out. Methods for distinguishing liquid phase from gas-phase corrosion on ferritic alloys are presented.

Ash Composition Influence on Fusibility of Coal Ash

2013 ◽  
Vol 448-453 ◽  
pp. 3009-3012
Author(s):  
Na Gao ◽  
Sheng Hua Liu ◽  
Yan Hong Guo
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Mineral Composition ◽  
General Trend ◽  
Coal Ash ◽  
Xrd Analysis ◽  
Fusion Temperature ◽  
Basic Oxide ◽  
Ash Composition ◽  
Ash Fusion Temperature

The coal of Zichang was selected as the sample coal, the physical properties of the ash is analyzed with ICP-AES. The ash fusion temperature was researched by adding different basic oxide contents. The results show that the general trend is decrease firstly, and then increase when adding basic oxides. Blended ash fusion temperatures do not change linearly with blending ratios and ash fusion will decrease when adding the contents of CaO, Na2O and MgO, but the effect is different. Na2O is best and CaO is second. Mineral composition and type at addition oxides were determined by XRD analysis. Some combinations of component coals mineral produce eutectic minerals at high temperature;It can explain the reason of oxides decrease the ash fusion. Vitreous minerals are formed to explain increase the fusion temperature.

Relationship between coal ash composition and ash fusion temperatures

Fuel ◽  
2013 ◽  
Vol 105 ◽  
pp. 293-300 ◽  
Author(s):  
Bo Liu ◽  
Qihui He ◽  
Zihao Jiang ◽  
Renfu Xu ◽  
Baixing Hu
Keyword(s):  
Coal Ash ◽  
Ash Composition

High-Temperature Erosion Resistance of Coatings for Gas Turbine

1992 ◽  
Vol 114 (2) ◽  
pp. 242-249 ◽  
Author(s):  
W. Tabakoff ◽  
A. Hamed ◽  
M. Metwally ◽  
M. Pasin
Keyword(s):  
High Temperature ◽  
Protective Coatings ◽  
Coal Ash ◽  
Mass Effect ◽  
Impact Angle ◽  
Unit Weight ◽  
Weight Losses ◽  
Aluminide Coatings ◽  
Particle Flows ◽  
The Impact

An experimental investigation was conducted to study the ash particle rebound characteristics and the associated erosion behavior of superalloys and aluminide coatings subjected to gas-particle flows at elevated temperature. A three-component LDV system was used to measure the restitution parameters of 15 micron mean diameter coal-ash particles impacting some widely used superalloys and coatings at different angles. The presented results show the variation of the particle restitution ratios with the impingement angle for the coated and uncoated superalloys. The erosion behaviors of INCO-738, MAR 246 and X40 superalloys and protective coatings C, N, RT22 and RT22B also have been investigated experimentally at high temperature using a specially designed erosion tunnel. The erosion results show the effect of velocity, temperature and the impact angle on the erosion rate (weight loss per unit weight of particles). Based on the experimental results of the particle mass effect on both weight losses and erosion rates, the coating lives have been estimated for different particle concentrations.

Influence of ash composition on high temperature CO2 sorption

2019 ◽  
Vol 7 (2) ◽  
pp. 103017 ◽  
Author(s):  
Barbora Miklová ◽  
Marek Staf ◽  
Veronika Kyselová
Keyword(s):  
High Temperature ◽  
Ash Composition ◽  
Co2 Sorption

A Thermodynamically Based Model for Ash Fusion Temperature

1987 ◽  
Vol 109 (3) ◽  
pp. 124-128 ◽  
Author(s):  
R. R. Rhinehart ◽  
A. A. Attar
Keyword(s):  
Standard Error ◽  
Coal Ash ◽  
Model Parameters ◽  
Fusion Temperature ◽  
Ash Composition ◽  
Parameter Correlation ◽  
Ash Fusion Temperature ◽  
Wide Range

This paper describes a thermodynamically based correlation between coal ash fusion temperatures and ash composition. A wide range of data from the literature was used to obtain the values of model parameters. A seven-parameter correlation is proposed which permits predicting the ash fusion temperature with a standard error ± 65°C or better.

A Laboratory Study of High-Temperature Corrosion on Fireside Surfaces of Coal-Fired Steam Generators

1968 ◽  
Vol 90 (2) ◽  
pp. 193-198 ◽  
Author(s):  
S. A. Goldberg ◽  
J. J. Gallagher ◽  
A. A. Orning
Keyword(s):  
High Temperature ◽  
Steam Generators ◽  
Fireside Corrosion ◽  
Significant Information ◽  
Metal Chlorides ◽  
Mixed Alkali ◽  
Electrolytic Corrosion ◽  
Gas Atmosphere ◽  
Experimental Approaches ◽  
Gas Flame

Three experimental approaches gave significant information on high-temperature fireside corrosion: 1 Sodium and potassium chlorides, injected through a gas flame, were deposited as such and then converted to sulfates on an iron surface. 2 Samples of mixed alkali and iron sulfates first showed decomposition and then formed melts at temperatures as low as 1070 deg F. This temperature is within the range that might be expected for fireside surface temperatures on superheater and reheater tubes of large steam generators. 3 Alkali metal chlorides and sulfates, in partial coverage of metal disks and in a flue gas atmosphere, formed fused deposits at temperatures as low as 900 deg F. Complex alkali iron sulfates may cause corrosion either by direct electrolytic corrosion or by altering the normally protective iron oxide scale so that the metal is exposed to direct oxidative corrosion.

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