Estimation of Thermodiffusion Influence on Formation of Transition Zones during Brazing

2016 ◽  
Vol 712 ◽  
pp. 379-383
Author(s):  
Marija V. Chepak-Gizbrekht
Keyword(s):  
Mass Transfer ◽  
Active Element ◽  
Transition Zones ◽  
Contact Boundaries

The work formulates a particular problem on redistribution of an active element from brazing alloy into brazed materials with due account for thermodiffusion effect. The analysis of the solution has demonstrated that thermodiffusion can facilitate the acceleration of mass transfer from brazing alloy into brazed materials and cause the accumulation of components in the vicinity of contact boundaries.

Characterization of dissolved material during the initial phase of softwood kraft pulping

TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 37-43 ◽  
Author(s):  
HANNU PAKKANEN ◽  
TEEMU PALOHEIMO ◽  
RAIMO ALÉN
Keyword(s):  
Mass Transfer ◽  
Molecular Mass ◽  
Initial Phase ◽  
Degradation Products ◽  
Kraft Pulping ◽  
Reaction Products ◽  
Cooking Temperature ◽  
Molecular Masses ◽  
Aliphatic Carboxylic Acids

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.

Prediction of Mass Transfer in Hot Metal Reactors

2019 ◽  
Author(s):  
L. Oliveira Campos ◽  
P. Gardin ◽  
S. Vincent
Keyword(s):  
Mass Transfer ◽  
Hot Metal

Diffusive mass transfer in island films

1978 ◽  
Vol 125 (7) ◽  
pp. 489-525 ◽  
Author(s):  
Ya.E. Geguzin ◽  
Yu.S. Kaganovskii
Keyword(s):  
Mass Transfer ◽  
Diffusive Mass Transfer ◽  
Island Films
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