*Absorción: Coeficientes de transferencia de masa. Problema 1... Parte 2
Música
The video starts with music.
Calculating Mass Transfer Coefficients
- Understanding the different units required for calculating mass transfer coefficients: mol fraction, mole ratio, weight fraction, molar density.
- Importance of having known coefficients in different units to proceed with calculations.
- Steps to calculate the individual volumetric coefficient starting from volumetric flux for ammonia.
- Formula for finding the individual volumetric coefficient using known and unknown concentrations in the liquid phase.
- Algebraic manipulation to derive the individual volumetric coefficient equation.
Density Calculations for Solutions
- Inability to solve for the coefficient without total liquid density unless considering diluted solutions where only water is predominant.
- Total liquid density calculation in grams per cubic centimeter.
- Conversion of total density from mass to moles per cubic foot.
Final Coefficient Calculation
- Transformation of total density into molar density and further calculations involving molecular weights to obtain a final value.
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In this section, the speaker discusses the calculation of the concentration unit coefficient in a liquid phase.
Calculation of Concentration Unit Coefficient
- The concentration unit coefficient is calculated as 118.27 pounds per hour per cubic foot multiplied by the Delta X.
- The unknown value, K subscript x uppercase, is determined by multiplying K lowercase x interfacial by X uppercase since we are in the liquid phase.
- The individual coefficient kla is obtained by multiplying kla with molar densities according to a transformation previously discussed.
- By equating terms in gas and liquid phases, an expression involving binomials is derived for Kx.
- For dilute solutions where values tend towards zero, Kx equals kla and its value is 118.27 pounds per hour per cubic foot.
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This part focuses on finding the individual volumetric mass transfer coefficient for weight fraction concentration in the liquid phase.
Finding Individual Volumetric Mass Transfer Coefficient
- To find the coefficient, start with a known value of molar density in the liquid phase.
- Convert this known value to a volumetric mass transfer coefficient for weight fraction and then to a relationship mall coefficient.
- Proceed to an X uppercase state coefficient and finally arrive at an individual volumetric mass transfer coefficient without weight fraction concentration.
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Here, the process of deriving coefficients involving molecular weights and concentrations is explained.
Deriving Coefficients with Molecular Weights
- Start with a volumetric flux equation equaling an unknown value.
- Express the individual volumetric mass transfer coefficient for weight fraction multiplied by its gradient as kla times (X minus Xa).
- Simplify further using molecular weights: divide by molecular weights to convert weight fractions to mole fractions.
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This segment delves into canceling terms through conversions from weight fractions to mole fractions.
Converting Weight Fractions to Mole Fractions
- Cancel out terms like X minus Xa through converting weight fractions to mole fractions.
- Utilize common factors such as total liquid density and molecular weights for simplification.
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The discussion centers on determining the molecular weight of solutions based on specific calculations.
Determining Molecular Weight of Solutions
- Calculate the molecular weight of solutions considering water's molecular weight as 18 pounds per pound-mole.
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Explanation of cubic foot, kla value, and their relationship.
Understanding Cubic Foot and kla Value
- : Discussion on the cubic foot measurement and its relevance.
- : Mention of multiplying by kla, with kla specified as 34 pounds.
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Exploring time and the cubic gradient at sea level in the interface.
Time and Cubic Gradient
- : Focus on time-related aspects.
- : Reference to the cubic gradient at sea level within the interface.
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Calculation involving cubic feet, density total, and maintaining values through a specific formula.
Calculating Cubic Feet and Density Total
- : Explanation of canceling out cubic feet to reach a total density figure.
- : Utilizing a formula resulting in 125.13 pounds per hour per cubic foot for fractional weight in the liquid phase at the interface.
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Determining individual volumetric mass transfer coefficient independently of component concentration for further calculations.
Individual Volumetric Mass Transfer Coefficient
- : Obtaining a coefficient independent of concentration for a specific component.
- : Exploring differences between diluted and concentrated concentrations affecting coefficients.
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Deriving coefficients based on known values and concentration factors for accurate calculations.
Deriving Coefficients
- : Dividing known values to determine coefficients accurately.
- : Describing the process to find individual volumetric coefficients based on component concentrations logarithmically.