Questions tagged [mass-transfer]
11 questions
4
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1 answer
Modelling gas desorption from a still solution (e.g. a beer)
The common way to model or estimate gas (e.g. CO2) desorption rate from a liquid solution is by using an equation similar to this one
$J_{CO_2} = -k_L a(H·C^G_{CO_2} - C^L_{CO_2})$
where $J_{CO_2}$ is the molar (or mass) flowrate, $k_L$ is the mass…
Toulousain
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2
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When teaching separation processes, which one should be introduced first? Distillation or absorption?
I am preparing a basic course on Separation Processes (5th semester, BSc Chemical Engineering). I can see that many well-known textbooks (e.g. Seader & Henley, Wankat) start by teaching in detail distillation and only then, the chapters on…
Toulousain
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2
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2 answers
Does a tank of liquid nitrogen increase in total internal energy after emptying?
Suppose there's a 10 liter perfectly-insulated sealed tank of saturated liquid nitrogen at 4 bar. Therefore the fluid has properties,
$\rho=740 \,\frac{\text{kg}}{\text{m}^3}$,
$m=7.4 \,\text{kg}$,
$\hat{u}=-93\,\frac{\text{kJ}}{\text{kg}}$,
and…
Victor
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1
vote
1 answer
Under what conditions is grinding unnecessary for liquid-solid leaching in mineral processing?
I am a chemical engineering student and I am having trouble understanding a passage in a separation process textbook I am reading. The passage is about the preparing solids for leaching, such as grinding and crushing ores. At the end of the…
wlsa
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1
vote
1 answer
How to create a mechanical equivalent to dropping object onto steel floor
(I was informed on the Physics board that this is an Engineering question, therefore they closed it there, and I moved it here)
First, I have next to zero formal physics training... I opted for all math & electronics electives back in my 1970s high…
RTC
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1
vote
2 answers
How to calculate heat and mass transfer rates from an enclosed box?
I'd like to know if it's possible to calculate the heat and mass transfer rates from a small volume to the environment.
Let's assume there is a box with a small opening at the top. The air inside the box is hot and humid (65 °C and 100% relative…
Sergio
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1
vote
0 answers
Slow integration of system ODE under specific conditions in adsorption problem
I am trying to solve the system of ODEs below. I am applying the finite differences to z, so I get a system of ODE that I can solve with a solver like ode45.
The problem is that under the conditions that interest me integration is too slow (time…
Synergix
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1
vote
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Please help solve this problem!
Fluid with mdot = 0.025 kg/s and Tm,i = 25oC is flowing through a long metal
cylindrical tube where the diameter is 0.032 m and the length is 2 m. The surface of the tube is heated with a heat flux of 3000x^2 W/m2.
Tony
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1
vote
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Adsorption - what models are used for dry scrubbing?
For scrubbing with activated carbon, air is generally brought through a dry adsorption media, where the contaminant is adsorbed onto the media.
I would like to know what mathematical model is used for this process. I presume the rate of adsorption…
Mark
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0
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Why do we consider the normal component of velocity in a flux and not the original direction of velocity?
Below is the equation of convective flux of an arbitrary property that is carried by particles. When particles move they carry their property along with them. Given a fixed surface in space, in order to calculate the amount of property crossing a…
user134613
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Solving a linear mass balance equation in the form of Ax = 0 with variables in vector x
I have been tasked with solving a series of linear equations in the form of Ax = b, where b is the zero vector. Specifically, I have a matrix E which is 4x7 and a column vector r which is 7x1, as pictured:
I must solve for Er = 0.I'm having…
