Erratum: “Time-Dependent Deposition Characteristics of Fine Coal Fly Ash in a Laboratory Gas Turbine Environment” [ASME J. Turbomach., 2012, 135(2), p. 021003; DOI:10.1115/1.4006639]

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Robert G. Laycock ◽  
Thomas H. Fletcher
Keyword(s):  
Fly Ash ◽  
Gas Turbine ◽  
Coal Fly Ash ◽  
Time Dependent ◽  
Fine Coal

Time-Dependent Deposition Characteristics of Fine Coal Fly Ash in a Laboratory Gas Turbine Environment

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Robert G. Laycock ◽  
Thomas H. Fletcher
Keyword(s):  
Fly Ash ◽  
Surface Temperature ◽  
Gas Turbine ◽  
Gas Flow ◽  
Coal Fly Ash ◽  
Time Dependent ◽  
Gas Temperature ◽  
Brigham Young University ◽  
Fine Coal ◽  
Two Samples

Time-dependent deposition characteristics of fine coal fly ash were measured in the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University. Two samples of subbituminous coal fly ash, with mass mean diameters of 3 μm and 13 μm, were entrained in a hot gas flow with a gas temperature of 1288 °C and Mach number of 0.25. A nickel-based, superalloy metal coupon approximately 0.3 cm thick was held in a hot particle-laden gas stream to simulate deposition in a gas turbine. Tests were conducted with deposition times of 20, 40, and 60 min. Capture efficiencies and surface roughness characteristics (e.g., Ra) were obtained at different times. Capture efficiency increased exponentially with time, while Ra increased linearly with time. The increased deposition with time caused the surface temperature of the deposit to increase. The increased surface temperature caused more softening, increasing the propensity for impacting particles to stick to the surface. These data are important for improving models of deposition in turbines from syngas flows.

Time-Dependent Deposition Characteristics of Fine Coal Flyash in a Laboratory Gas Turbine Environment

2011 ◽  
Author(s):  
Robert G. Laycock ◽  
Thomas H. Fletcher
Keyword(s):  
Surface Temperature ◽  
Gas Turbine ◽  
Gas Flow ◽  
Coal Fly Ash ◽  
Time Dependent ◽  
Gas Temperature ◽  
Brigham Young University ◽  
Fine Coal ◽  
Two Samples ◽  
Nickel Base

Time-dependent deposition characteristics of fine coal flyash were measured in the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University. Two samples of subbituminous coal fly ash, with mass mean diameters of 3 and 13 μm, were entrained in a hot gas flow with a gas temperature of 1250°C and Mach number of 0.25. A nickel base super alloy metal coupon approximately 0.3 cm thick was held in a hot particle-laden gas stream to simulate deposition in a gas turbine. Tests were conducted with deposition times of 20, 40, and 60 minutes. Capture efficiencies and surface roughness characteristics (e.g., Ra) were obtained at different times. Capture efficiency increased exponentially with time while Ra increased linearly with time. The increased deposition with time caused the surface temperature of the deposit to increase. The increased surface temperature caused more softening, increasing the propensity for impacting particles to stick to the surface. These data are important for improving models of deposition in turbines from syngas flows.

Time-dependent leaching of coal fly ash by chelating agents

1983 ◽  
Vol 17 (3) ◽  
pp. 139-145 ◽  
Author(s):  
Wesley R. Harris ◽  
David. Silberman
Keyword(s):  
Fly Ash ◽  
Chelating Agents ◽  
Coal Fly Ash ◽  
Time Dependent

Independent Effects of Surface and Gas Temperature on Coal Fly Ash Deposition in Gas Turbines at Temperatures up to 1400 °C

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Robert Laycock ◽  
Thomas H. Fletcher
Keyword(s):  
Fly Ash ◽  
Surface Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Coal Fly Ash ◽  
Combined Cycle ◽  
Capture Efficiency ◽  
Gas Temperature ◽  
Independent Effects

Deposition of coal fly ash in gas turbines has been studied to support the concept of integrated gasification combined cycle (IGCC). Although particle filters are used in IGCC, small amounts of ash particles less than 5 μm in diameter enter the gas turbine. Previous deposition experiments in the literature have been conducted at temperatures up to about 1288 °C. However, few tests have been conducted that reveal the independent effects of gas and surface temperature, and most have been conducted at gas temperatures lower than 1400 °C. The independent effects of gas and surface temperature on particle deposition in a gas turbine environment were measured using the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University. Gas temperatures were measured with a type K thermocouple and surface temperatures were measured with two-color pyrometry. This facility was modified for testing at temperatures up to 1400 °C. Subbituminous coal fly ash, with a mass mean diameter of 4 μm, was entrained in a hot gas flow at a Mach number of 0.25. A nickel base super alloy metal coupon 2.5 cm in diameter was held in this gas stream to simulate deposition in a gas turbine. The gas temperature (and hence particle temperature) governs the softening and viscosity of the particle, while the surface temperature governs the stickiness of the deposit. Two test series were therefore conducted. The first series used backside cooling to hold the initial temperature of the deposition surface (Ts,i) constant at 1000 °C while varying the gas temperature (Tg) from 1250 °C to 1400 °C. The second series held Tg constant at 1400 °C while varying Ts,i from 1050 °C to 1200 °C by varying the amount of backside cooling. Capture efficiency and surface roughness were calculated. Capture efficiency increased with increasing Tg. Capture efficiency also initially increased with Ts,i until a certain threshold temperature where capture efficiency began to decrease with increasing Ts,i.

UTILIZATION OF COAL FLY ASH FROM POWER PLANTS - I. ASH CHARACTERIZATION

2008 ◽  
Vol 7 (3) ◽  
pp. 289-293 ◽  
Author(s):  
Maria Harja ◽  
Marinela Barbuta ◽  
Lacramioara Rusu ◽  
Nicolae Apostolescu
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Coal Fly Ash

scholarly journals Coal Fly Ash and Polyacrylamide Influence Transport and Redistribution of Soil Nitrogen in a Sandy Sloping Land

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Kai Yang ◽  
Zejun Tang ◽  
Jianzhang Feng
Keyword(s):  
Fly Ash ◽  
Sandy Soil ◽  
Coal Fly Ash ◽  
Soil Layer ◽  
Nutrient Retention ◽  
Soil Surface ◽  
Rainfall Event ◽  
N Losses ◽  
N Concentration ◽  
Application Rates

Sandy soils are prone to nutrient losses, and consequently do not have as much as agricultural productivity as other soils. In this study, coal fly ash (CFA) and anionic polyacrylamide (PAM) granules were used as a sandy soil amendment. The two additives were incorporated to the sandy soil layer (depth of 0.2 m, slope gradient of 10°) at three CFA dosages and two PAM dosages. Urea was applied uniformly onto the low-nitrogen (N) soil surface prior to the simulated rainfall experiment (rainfall intensity of 1.5 mm/min). The results showed that compared with no addition of CFA and PAM, the addition of CFA and/or PAM caused some increases in the cumulative NO3−-N and NH4+-N losses with surface runoff; when the rainfall event ended, 15% CFA alone treatment and 0.01–0.02% PAM alone treatment resulted in small but significant increases in the cumulative runoff-associated NO3−-N concentration (p < 0.05), meanwhile 10% CFA + 0.01% PAM treatment and 15% CFA alone treatment resulted in nonsignificant small increases in the cumulative runoff-associated NH4+-N concentration (p > 0.05). After the rainfall event, both CFA and PAM alone treatments increased the concentrations of NO3−-N and NH4+-N retained in the sandy soil layer compared with the unamended soil. As the CFA and PAM co-application rates increased, the additive effect of CFA and PAM on improving the nutrient retention of sandy soil increased.

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