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4700 |
Tubes damaged by erosion-corrosion because of the erosive action of the soot
blowers. (foto KEMA) (ref 50, Fig 1). |
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4701 |
The topotactically grown corrosion scale. In the oxide layer many sulphides
are found. The sulphides have also grown in the cracks of the oxide. (foto KEMA) (ref 50, Fig 2). |
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4702 |
At the metal-oxide interface the element Cl is sometimes found. In a few
cases this resulted in severe intergranular corrosion. (foto KEMA) (ref 50, Fig 3). |
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4710 |
A Scanning Electron Microscope image, the places of presence of heavy
metals are blue (detail of Figure 1). (foto KEMA) (ref 50, Fig 4). |
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4711 |
Typical Alligator Skin Cracks in one of the tubes at the rear water wall. (foto KEMA) (ref 50, Fig 5). |
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4712 |
The high-sulphide layer on the corrosion probe, after 4 weeks of operation. (foto KEMA) (ref 50, Fig 6). |
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4713 |
The oxide layer after adjustment of the burners and air curtain introduction. The layer is more protective now. (foto KEMA) (ref 50, Fig 7). |
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4714 |
The calculated and measured corrosion rate constants in a sulphidising gas. (foto KEMA) (ref 50, Fig 8). |
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4715 |
An example of calculating the corrosion at 375 °C of the tube wall based on the data of the gas measurements. A parabolic corrosion rate has been assumed. (foto KEMA) (ref 50, Fig 9). |
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4730 |
Figure 1. Optical microscopic image of the fire side tube deposit. |
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4731 |
Figure 2 SEM Backscatter electron image. The white particles contain lead. |
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4732 |
Figure 3. Decay chain of 238U |
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4740 |
The thermodynamically stable constituents of lead in an oxidizing gas environment O1. The lead condensation (dewpoint) temperature is 880°C at respectively 50 vppm HCl. (ref 51). |
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4741 |
In the oxidizing gas environment O2 the lead condensation (dewpoint) temperature is 770 °C at respectively 500 vppm HCl. (ref 51). |
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4742 |
In the oxidising gas O3 with 5000 vppm HCl lead condensates at 660 ° . (ref 51). |
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4743 |
The thermodynamically stable constituents of lead in the reducing gas environment R1. The lead condensation (dewpoint) temperatures are 680 °C at 500 vppm H2S and respectively 50 vppm HCl. (ref 51). |
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4744 |
In the reducing gas R2 with 500 vppm H2S and 500 vppm HCl Pb condensates at 670 °C . (ref 51). |
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4745 |
Lead has a condensation (dewpoint) temperature of 495 °C in the reducing gas R3 with 500 vppm H2S and 5000 vppm HCl. (ref 51). |
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4746 |
Lead condensates at 650, °C in the reducing gas R4 with 500 vpmm HCl and 50 vppm H2S. (ref 51). |
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4747 |
The lead condensation (dewpoint) temperature is 670 °C in the reducing gas environment R2at 500 vpmm HCl and respectively 500 vppm H2S. (ref 51). |
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4748 |
Pb condensates at 680 °C in the reducing gas environment R5 with at 500 vpmm HCl and 5000 vppm H2S. (ref 51). |
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4750 |
Cross section of one of the deposition probes after an exposure period of 4 months. The element Pb is present on the white areas on the interface between the thick porous deposit of fly ash and the outer oxide layer. (foto KEMA)(ref 51). |
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4760 |
Layer structure on a evaporator tube at oxidising and reducing firing conditions. (ref 37, Fig 2) |
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4761 |
Cross section of oxide layer on a evaporator tube in the DSM demonstration project (foto KEMA) (ref 37, Fig 3) |
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4762 |
Cross sections of samples exposed in sulfidising gas at 450°C. Samples C and D were exposed in NaCl containg sulfidising gas. (foto KEMA) (ref 37, Fig 4) |
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4763 |
Cross sections of samples exposed in sulfidising gas B with sodiumsulphate on the samples at 450°C. (foto KEMA) (ref 37, Fig 5). |
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4764 |
Tubes with Alligator Skin Cracking published in EPRI-rapport CS-4969 (Cialone, 1986). (ref 37, Fig 6). |
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4765 |
Figure from EPRI-rapport CS 4969. Photo A: cross section of of a crack filled with oxide and sulfide. Photo B: detail of the oxide and sulphide filled "Alligator Skin Crack". (ref 37, Fig 7). |
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4766 |
Afb. 8 Een 10CrMo910-staafje van een CERT-experiment bij 400 °C in het sulfiderend gas B. Zeer
duidelijke brosse breukindicaties worden aangetroffen. |
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4767 |
Afb. 9 Doorsnede van het CERT-staafje uit afb. 8. Er zijn verschillende typen scheuren aanwezig in het niet ingesnoerde gedeelte van het staaf je. |
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