CN3124 2021 Part2 (Dr Cindy) by Cindy Lee

WELCOME to PART 2 of CN3124A

chellyc — 2021-02-28 12:24:37 UTC

Hi Students, you are welcome to discuss, ask questions related to the module in this platform. Visit this space frequently if you want to also see what are some topics discussed by your peers!

2021-03-02 04:05:05 UTC

Hi, Dr Cindy! For the sauter mean diameter, is it the diameter of a sphere with equivalent surface area/volume as the particle or volume/surface area? Thank you!

CN3124A Recordings

2021-03-03 12:34:44 UTC

Hi Prof, may we know how we can access the lecture recordings?

Unit balance for Darcy's Law

2021-03-04 04:09:54 UTC

Hi Prof, may I check what is wrong with the units below for the parameters in Darcy's Law? Cannot seem to balance the units
velocity, u (m/s)
viscosity, miu (Pa.s)
Permeability Coeff, K (dimensionless)
Thickness, L (m)
Pressure drop, -delta P (Pa)

Equations

2021-03-04 09:25:58 UTC

Dear Dr Cindy,

When do we use the formula for u and when do we use the formula for u' when solving questions? Do both of the formula work on cylindrical pipe?
A little confused here. Thanks!

CN3124A Tutorial Recording

2021-03-08 15:28:59 UTC

Hi Prof, when will the tutorial recordings be uploaded to luminus?

thanks in advance!

C-K equation

2021-03-09 04:06:11 UTC

Hi prof, when should we take the limitations of C-K equation into account?

Form of Ergun Equation for Packed Beds

2021-03-11 12:24:47 UTC

Hi Prof, when finding pressure drop using Ergun equation, is it better to use:
f' = 4.17(Re')^-1 + 0.29 (1st eqn in slide 24 of lecture notes)
or
the pressure drop equation (2nd eqn in slide 24 of lecture notes)?

The two equations can result in different answers, so is there a preferred one? Or is it okay as long as we indicate which eqn is used in our answers?

Homework for Part 2 of CN3124A

2021-03-11 12:38:27 UTC

Hi Prof, may I know when will the guidelines and deadlines for each homework be released?

thanks,

D and ds

2021-03-13 03:53:34 UTC

Hi Dr Cindy,

Does D and ds mean the same thing in the minimum fluidisation velocity equations?

L9 slide 20

2021-03-13 14:21:51 UTC

Hi Prof,
for the Ga number ranges given on slide 20, will there be a case where Ga = 3.6 ? and in this case which range should we be using ?

thanks

2021-03-15 04:03:16 UTC

Hi Prof, just to confirm, the D here we just change to small d notation to represent particle size instead right? cause u mentioned during lecture. so from this slide onwards, we use the notation small d instead right?

The value of S for S(1-E)

2021-03-15 04:29:04 UTC

Hi prof, why sometimes we take S=6 and sometimes we take S/d? Like for the modified Re the S is taken as 6, but for the f’ the S is taken as S/d. Thank you.

Ergun's eqn difference in calculated delta P/L when using f' and full equation for tutorial 8 q2

2021-03-16 12:26:02 UTC

Dear Prof
Redoing Tutorial 8 using the first equation instead of the f' with delta P/L relation gives slightly different values for he pressure drop. Which should we use for more accurate calculations?

Tutorial 9, q2 ii

2021-03-16 14:49:30 UTC

Dear Prof
When we do q2 ii, how do we know that we are still not in the fluidization regime? It seems that it is just coincidence that the velocity that we used in the calculation is not greater than u mf. Does this mean that normally, we should find u mf first to determine if we are still in the packed bed regime, or the fluidization regime?

Terminal Velocity

2021-03-17 09:11:17 UTC

Dear Prof,

Does entrainment and terminal veloctiy mean the same thing?

Quiz 2

2021-03-17 15:16:13 UTC

Dear Prof,

can we have the breakdown of the number of questions we have for the quiz? (For mcq and fill-in-blanks)

Lecture 10, what is G?

2021-03-18 04:09:09 UTC

Dear Prof in our textbook, it states that G is the particle flux (kg/(m^2 . s). Is there a difference between the G introduced in lecture and the one stated in the textbook?

Thanks in advance!

Unit 10, Up for Horizontal Transport

2021-03-18 04:25:27 UTC

Hi Prof,
for this Up correlation do we only use it if there is no other way to calculate Up (E.g no voidage given). Or must we use this Up specifically in the calculation of Fpw only?

2021-03-18 15:38:08 UTC

Hi Prof, the questions for the quiz won't be so excel intensive like tutorial 8 question3 right?

L8 example 1b

2021-03-18 17:33:37 UTC

For this example, why did u not calculate the value of Umf to determine if the velocity is high enough to cause the packed bed to fluidize?

Tutorial 9

2021-03-19 11:29:24 UTC

Hi Prof, is it possible if you can upload tutorial 9 solutions?

Area

2021-03-19 11:29:52 UTC

Hi prof, does all A in your portion refers to reference area in general?

Thurs Lecture

2021-03-20 03:44:45 UTC

Dear Prof,

When will thurs lecture recording be uploaded?

Thank you!

Google

2021-03-20 04:38:51 UTC

Dear Prof,

are we allowed to use google during the quiz?

Midterm

2021-03-21 13:19:35 UTC

Hi prof,
is the standard for the midterm qns similar to those of tutorial?

L8 Tutorial Q2

2021-03-22 07:05:05 UTC

Hi Prof., can I check why can we use the relation "1 - rho_bulk/rho_particle = e" when the fluid is water? In the lecture notes, it seems that we derived this based on the condition that the fluid is air.

2021-03-22 07:58:55 UTC

Hi Prof, is finding the mean bed voidage in part c within the scope of the quiz? This qn is from the TB

2021-03-22 08:14:56 UTC

Hi Prof, can you help me check my working for qn 7.4 part (b)? i feel like my flow of working is correct but idk why my answer does not tally with the TB's final answer of 7876 Pa. Thanks

2021-03-22 09:22:58 UTC

Hi Prof, is it possible to check my working for qn 7.6 part c as well

Homework 3

2021-03-24 05:03:09 UTC

Hi Prof, is there any page limit for HW3?

homework 3

2021-03-24 16:54:45 UTC

hi prof, free falling velocity is it terminal falling velocity?

Homework 3

2021-03-25 10:19:48 UTC

Hi prof, for HW3: Are we supposed to/ can we assume voidage Emf =0.4?

Homewok 3

2021-03-25 13:52:35 UTC

Hi prof for HW3, we don't have to do it on word right? I can just write on pen paper and then for the graphs, i just add it into the pdf?

HW 3

2021-03-25 15:20:03 UTC

Dear Dr cindy,

For the graph, can we plot using pen and paper or must we use excel?

Tutorial L10

2021-03-25 15:50:28 UTC

Hi prof, when will tutorial 10 be available, thank u !

Homework 3

2021-03-26 03:55:30 UTC

Hi prof, for the graph plotting part of the hw, are we supposed to use the umf values we calculated from part (i)?

homework 3

2021-03-26 03:59:13 UTC

Hi prof,
for the graph, is it ok to sketch it on paper and label the umf, ut and the respective delta P? or is it a must to plot it on excel?
thank you!

HW3

2021-03-26 11:28:37 UTC

Prof, is there any page limit for the HW3 and can i submit the excel file instead of pasting the graph in the word doc?

2021-03-26 11:46:03 UTC

Hi prof, for the graph, is it ok to sketch it on paper and label the umf, ut and the respective delta P? or is it a must to plot it on excel? thank you!

HW3

2021-03-26 11:56:26 UTC

Prof, for the Geldart classification, are we supposed to look at the table of the graph? or both are fine? if looking on the table, should we choose the line that is closest to the point?

homework 3

2021-03-27 05:38:32 UTC

hi prof is the homework marked on effort basis (like in sweekun's part) or based on accuracy?

HW3

2021-03-27 05:57:46 UTC

Hi Prof, may i ask what is the length of the bed?

(-ΔP) fluidised bed

2021-03-27 17:04:15 UTC

Hi Prof,
When u = 0 is the pressure drop 0 or infinity?

HW3

2021-03-27 17:35:57 UTC

Hi Prof,
For the plotting of graphs, must we plot 6 separate graphs? or can we combine the 300K and 350K graphs for Bed A into one graph?

HW3: Do we only show the worked calculations for the beds operating at air @ 300K? Or must we show for air at 350K as well?

2021-03-28 02:28:47 UTC

Prof, hw3 is just purely using calculations and plotting of graphs right? No explanations needed?

2021-03-28 03:10:37 UTC

Cyclone slide 8 error

2021-03-28 12:56:20 UTC

Hi Prof, I saw that the slides had S = ½DB + 1⁄8DB, which seems to be a typo.
The notes have the correlation as S = 2DB+1/8 DB instead. (I double checked with the textbook)

HW 3

2021-03-29 01:30:24 UTC

Hi prof,
for my hw i wrote the workings on paper and the graphs are in excel, so would it be ok if i submit 2 separate files put into one folder (one file is pdf of my workings and another is word/excel with all my graphs)?
Or should everything be in one file?
Thank you!

HW 3

2021-03-29 04:27:47 UTC

Dear Prof,

For the Hw i can do the calculations on pen and paper right? I don't have to do the calculations on word/excel right?Then for the graph i just use excel seperately.

Prof, is homework 3 similar to tutorial 9 qn 1?

2021-03-29 07:53:00 UTC

Tutorial 9

2021-03-29 14:43:26 UTC

Hi Prof, can you upload the solution to Q3 for tut 9? I can't seem to get the same value when I calculate n

Tutorial 10 Reynold's number

2021-03-29 14:44:21 UTC

Hi Prof, how did you obtain the (UpH-UfH) in the equation for the Reynold's number? Shouldnt it just be x*UpH*pf/miu ?

HW3

2021-03-30 06:09:32 UTC

Prof, may I know how many HW left are after HW3?

HW3

2021-03-30 06:43:56 UTC

Prof, for HW3 part 2, do we also need to show the working for pressure drop?

HW3

2021-03-30 08:40:10 UTC

Prof, do we need to submit the excel file tgt with the word as most of the pressure drop calculations were done on excel?

HW3

2021-03-31 09:34:49 UTC

Hi Prof, we have to assume a voidage and L of bed to obtain the u_mf? Then from there calculate the flowrates?

Tut 10

2021-03-31 15:21:09 UTC

Hi prof, will questions like tut 10 come out in exams? i am not sure if i can solve it within 2 hours

HW3: Geldart's classification

2021-03-31 15:26:01 UTC

Are we allowed to just follow the table in L9

HW3 graph

2021-04-01 00:03:30 UTC

Hi prof,
Since we are required to plot ΔP for u =0 to 3umf, at some point the bed should fluidise meaning voidage will change too. can we just assume that the bed is fixed hence voidage is constant to plot the graph?

hw3 file name

2021-04-01 02:57:19 UTC

Hi prof,
is there a specific format to name the file? thank you!

Tutorial 9 Qn 3

2021-04-01 03:57:15 UTC

Why do we get a different answer when solving this problem by equating the pressure drop equation for fluidized beds to the Ergun’s Eqn (as shown below)?

Is fundamentally incorrect to use this method?

Hw3

2021-04-01 04:02:49 UTC

Hi prof,

I understand that if I use ck eqn or ergun eqn, the answers would be slightly different. But its okay if I choose to use ergun for the entire hw right? Would I be penalized if I use ergun for laminar region even though I know ck more accurate?

HW 3

2021-04-01 07:59:02 UTC

Prof may I ask why is it necessary to plot the graph and not sketch? I have already plotted the graph on excel (only have 4 points) but I realize that it can easily be sketched too since there are no curves involved. So I would like know why is it as such. Thank you :)

HW4: Hi Prof, can you release HW4 earlier? We may need time to study for the upcoming exams, and may need to complete our assignments earlier.

2021-04-01 09:09:29 UTC

Design and Operation of Cyclone

2021-04-02 10:15:19 UTC

Prof, I wanna check on the design and operation of the reverse flow gas cyclones. In the video, you mention the high efficiency cyclone has a higher velocity and the higher rate means higher velocity as well. So may I know what exactly is the difference between these two cyclone types?

HW3 Graphs

2021-04-03 07:13:46 UTC

Is it just me or do some of the graphs look like straight lines even when using Ergun's? But when u do the math they are just really subtle curves. Will we get penalized if our ergun graph looks too linear?

L10

2021-04-03 16:19:18 UTC

Dear Prof

Pneumatic calculations will not be tested for exam and only the concept of it will be tested for exam right?

Rhodes Excersise 8.1

2021-04-04 04:57:24 UTC

Dear Prof,
May I check how should we arrive at the ans for part (b) of this qn? I modified your excel to use their given equation for the friction factor. But, i still obtained an answer of 0.492bar instead of 0.55 bar...
Thank you

Tut 10

2021-04-04 15:58:20 UTC

Hi Dr Cindy,

I am a bit confused and was wondering how the drag coefficient was calculated in the excel sheet. The formula used was 18.5*Re^-0.6. I can't seem to find any formula for this; I can only find the CD equations from chapter 2 of the Rhodes textbook. Is there a page or slide that this relation is from?

Also I do not know where the formula to calculate pressure drop due to fluid-pipe friction was obtained from for the horizontal section and also the f(e) for the vertical section.

Thank you!

Quiz and Hw 4

2021-04-05 06:51:12 UTC

Hi prof, sorry to rush you but will you be releasing the solutions for the quiz and hw 4 this week?

HW4

2021-04-05 11:44:03 UTC

Hi Prof,
are we making the same assumption of 1. U=1.5xUsalt
2. pressure for bends = 7.5x vertical pressure drop?
3. bends are 90 degree
4. properties of gas = air?
5. mass flow rate = 900kg/h?

Quiz Solutions

2021-04-05 18:12:29 UTC

Hi Prof,

Could you upload the answers for the quiz?

HW4 spreadsheet use

2021-04-06 01:49:33 UTC

Hi prof, since you stated to use the spreadsheet, do we directly state the values obtained from it (or do we need to write the working)? E.g Usalt

for HW3

2021-04-06 01:51:14 UTC

Hello prof, is it okay if I just show one sample calculation since the procedure for all 3 beds are rather similar for all 2 air temperatures?

Gas to solids feed ratio

2021-04-06 02:12:07 UTC

Hi prof, sorry just wanted to double check:
By the definition of solids loading, the gas to solids feed ratio is its inverse right (according to units)?

Quiz

2021-04-06 04:11:26 UTC

Hi Prof, could you upload the number of marks awarded for each question in the quiz?

HW 4 deadline

2021-04-06 04:54:34 UTC

Hi Prof, when is the HW 4 deadline?

HW4

2021-04-06 06:34:59 UTC

Hi prof, we are supposed to determine either a) b) or c) for both sand and catalyst right?

HW 3

2021-04-06 07:08:39 UTC

Hi Prof, do we have to submit the excel file that shows the data points that we used to plot the graph?

Or we don't have to submit the excel file plus the table of data point because I used 40 data points and I think it cannot fit on a single page....

HW4

2021-04-06 07:18:24 UTC

Hi Prof, Pressure drop (bar) across the pneumatic conveying line includes horizontal, vertical and bend?

T10

2021-04-06 10:34:27 UTC

Hi Prof, can I check that the U calculated in tutorial 10 is the superficial gas velocity? In this case, Usalt is the superficial gas velocity that is so slow that it causes saltation to occurs?

HW4 Excel Solver

2021-04-06 12:26:31 UTC

Hi prof, for excel solver to find Uchoke, is there any reference initializing values to use for Uch and Ech? Cos if we use different initializing values to iterate with solver we get very different answers... Just wanted to check for consistency thanks!

HW4

2021-04-06 14:08:36 UTC

Hi Prof, is it possible to just submit the excel file for HW4?

2021-04-06 14:39:51 UTC

Prof, how to find gas to solid feed ratio? Don't recall seeing it in lect notes..

HW 4

2021-04-06 14:40:45 UTC

Dear Prof
is it possible if you can extend the dateline of HW 4 to 19 April 2021 as many of us have tests on week 13.

Chapter 10

2021-04-06 15:27:38 UTC

Hi prof, for G in this chapter, is it solid flux instead of solid feed rate ? Or are they both the same ? As I know that for flux, it contain a m2 so its quite confusing.

HW4

2021-04-06 15:55:00 UTC

Prof, may I know where we can get the F(fw)L formula? Is it same as the formula that is used to calculate F(pw)L but why don't we need to multiply by (1-voidage) if we are using the same formula?

Also, are we supposed to show one sample calculation for one of the materials?

HW4

2021-04-06 16:28:35 UTC

Prof, for part 2 of the HW, do we need to do for the two pipe diameters if I choose sand as the target particle or we just need to find one type of particle and do for one pipe diameter?

HW4

2021-04-07 08:15:03 UTC

Hi Prof, can you do an announcement on LumiNUS when the submission folder is open? Thanks!

HW4

2021-04-07 08:28:47 UTC

Hi prof, do we need to determine the gas to solids ratio, pressure drop and Usalt for both sand and catalyst, for BOTH 78 and 63mm?

HW4

2021-04-07 10:03:57 UTC

Prof, can I check how we should write down the workings for the part II of the HW4 as we just simply use the excel solver? Or do we need to briefly write down the steps of how we perform the solving function?

Eqn for Uch

2021-04-07 10:19:52 UTC

Hi prof, may I check if there was an error in your lecture since you mentioned the D in this eqn is for ds but the HW4 states the D as dtube?

HW4

2021-04-07 14:26:48 UTC

Prof, is this the formula to calculate the gas to solids feeds ratio?

HW4

2021-04-07 15:21:53 UTC

Why are we required to find gas to solid liquid ratio first then pressure drop then U salt? I thought Usalt is needed for part i and ii... or the order doesn't matter?

L12 Crystallization

2021-04-08 02:47:16 UTC

Prof, could you explain why heat removed from the solution equals to heat lost from the solution?

Heat removed is the heat of vaporization while heat lost is the heat of crystallization + sensible heat. I get it for sensible heat = vaporization since sensible is a change of temperature and vaporization produce a cooling effect to the solvent. But why heat of crystallization is in this equation? Isn't heat loss from crystals remains in the solvent?

Cyclone Tutorial

2021-04-08 04:03:13 UTC

hi prof, for part 1d, how do you know that the same grade efficiency can be used as the previous parts despite a different distribution? is it because its the same device?

chellyc — 2021-04-08 04:10:58 UTC

Prof, I initialize ech as 0.9 and Uch as 1, when i use excel solver to set the 2 equations to zero by constraining and all, it gives " not able to find a feasibl

Carman Kozeny & Ergun's equations

2021-04-08 09:16:32 UTC

I would like to clear a doubt. If we decide to use either Ergun's or the Carman-Kozeny equation, in finding both Umf and pressure drop, we should be consistent right? (i.e use either equation throughout to find Umf and pressure drop instead of, for example, using Carman-Kozeny equation to find Umf given that Re' < 2 and then find the corresponding pressure drop using Ergun's?

Equation for Choking Velocity and Alpha Clarification

2021-04-08 16:07:28 UTC

Hi prof,

The constants of the second equation for Choking Velocity and Alpha in the textbook is different from your slides, so could I seek your clarification on which values to use? Attached are the images for both equations for your comparison.

Martin Rhodes:
2250, 1440

Slides:
2550, 1400

(P.S. In the excel sheet, the constant used for alpha is 1440, which is using the textbook value)

HW 4

2021-04-09 03:18:43 UTC

Prof, for the Usalt, Pressure drop and gas to solid ratio can just state the answers directly from excel right? Dont need to show working?

HW4

2021-04-09 09:01:43 UTC

Prof, for HW4 part II, I encountered a problem when using Excel Solver. If using the Excel solver to solve simultaneous equations, the final values of U(ch) and ε(ch) will always change for different initial values. For example, if I put 1 and 0.9 for U and ε, the U will be very close to 1. But if I input 7 and 0.9, the value of U will change to 7 instead. May I know why this would happen (I have checked the formula many times, it's correct :<)

But if I don't solve the simultaneous equations, I use ε to represent U and then solve the values of ε which lead to the change of U. Then here the outputs will stabilize. So we should use this method instead?

Excel Help

2021-04-09 10:46:42 UTC

Hi for those who are Excel Savy, could you enlighten me on what values do i use for Excel Solver. (Max, Min, Value) .... my solver only gives me corresponding value of Ech when Uch is 0 or 1 so how do i do the iteration???
-from a currently lost coursemate

Lecture 10

2021-04-10 03:08:26 UTC

Hello prof, for your lecture 10 slides for the rizk equation you wrote 1400x+1.96 but in the tutorial and the textbook it was 1440x+1.96 can you clarify which is correct? Also you used d in your slides but in the tutorial and the textbook you used x to represent particle size which i found slightly confusing as d could mean diameter.

is there tutorial L12 in week 13 ? ._.

2021-04-10 18:34:09 UTC

HW4

2021-04-10 21:08:57 UTC

Hi prof, is it possible to extend the deadline of HW4? There are too many submissions next week already :-(

Solver grading

2021-04-11 06:14:50 UTC

Hi prof just wanna clarify how you will grade us for our Uch value found using excel solver since using diff initialising values will give different values.. Is it if we use reasonable values to initialise the iteration that thats acceptable already? Thanks !

Tutorial 11 Solutions

2021-04-12 03:06:21 UTC

Hi prof, could you please upload the solutions for tutorial 11?

Return of graded hwk(s)

2021-04-14 08:48:54 UTC

Hi Dr Cindy,

Will we be returned our graded hwk(s) before finals?

Thank you.

Homework 4

2021-04-14 09:29:31 UTC

prof, in the excel sheet for cell M15 which calculates the pressure for 1 metre of vertical, the formula used is divided by 10. but in the homework the vertical length is 20 so we are supposed to change it to 20 right?

also, when we do goalseek for ev and f(ev), the answer changes slighlty depending on the initial assumption of ev. can we just assume ev to be 0.5?

2021-04-14 14:16:57 UTC

hi prof will you be able to provide any questions w solutions / worked examples for nucleation?

MSMPR

2021-04-16 05:26:49 UTC

Prof when you mentioned that MSMPR wont be tested, does this mean the crystal size distribution and the industrial crystallisers portion also will not be tested?

Finals Format

2021-04-16 05:35:55 UTC

Hi Prof!!

For the finals, isit all structured questions or will there be MCQ like in the quiz?

Finals

2021-04-16 09:16:58 UTC

Hi prof, may I ask if there are additional resources to practise for finals or is it just tutorials or rhodes textbook?

FAQ on CRYSTALLIZATION:

chellyc — 2021-04-16 09:17:23 UTC

I have some FAQ on CRYSTALLIZATION via email so id like to share them here:
1) how come method to find w1 in question 1 is different from question 2?
ANS:
In question 1:

When we say SOLUTION, it Is made up of 120 kg of SOLUTION = w1 kg water + (120-w1)kg of salt (NaCl)

Since we are given that the concentration c1 = 0.3899 (0.3899 kg salt will dissolve in 1 kg water)

Therefore, we know that every 1.3899kg SOLUTION will contain 1kg water, and 0.3899kg of SALT.

Therefore, by proportion, for 120kg SOLUTION, w1 = 120 * (1/1.3899) kg

In question 2:

You are given the 1000kg of salt, and that the solution concentration (saturated) is 0.838kg in every kg water.

Hence here, to calculate w1, you will use w1 =1/0838 * 1000kg

The way to calculate is always using material balance. Key is understanding the question statement.

2) Does solubility has the same meaning as concentration? Since we have assigned solubility as c1 and c2 in the questions.

Solubility is the saturation concentration at that particular temperature. We have assigned CONCENTRATION as c1 as solubility because they question defined the solution as SATURATED. (i.e. at saturation concentration)

HOPE THIS HELPS! :)

Final

2021-04-19 00:15:54 UTC

Hi prof, how many questions total will there be for the final exam?

Practice Questions

2021-04-19 09:17:06 UTC

Prof, the Rhode book does not have the crystallization chapter so can you provide more practice questions for this chapter?

2021-04-19 09:26:28 UTC

Hi Prof, regarding the additional qn u gave us during the final tutorial, so how do i go about solving this? u told us to use mass balance of solute eqn, so based on that eqn, i need to find w2 and R first is it? like how do i go about doing that?

Crystallization tutorial

2021-04-19 09:55:49 UTC

Prof, for tutorial 12 qn2 part 2, I didn’t get it right cuz I simply used the w1c1=w2c2 +y/R to calculate. But I don’t get what this result means if it is not hydrated salt? Can you please explain what this y means here ?

Some questions on Cyclone seperators in series

2021-04-19 12:28:49 UTC

Hi prof, for seperators in series, do the Eu increase for subsequent cyclones?
For each of these cyclones, the pressure drop is taken from the top to the bottom that cyclone only? Or does it include the pressure drop of previous cyclones above?
Also, we will need to be given the individual pressure drop, V or Dcyc to calculate the final cut size correct?

Final Exam timing

2021-04-19 17:43:09 UTC

Hi prof is it possible to change the final exam timing to earlier timing on 26 April?

L11 CyCLONE

2021-04-20 01:21:09 UTC

Hi prof, how do I know whether it is the cumulative distribution or the frequency/probability distribution? for eg in tut, they state "size distribution" and it was frequency distribution?
will cumulative have a 1 for the last number?

final

2021-04-20 01:25:57 UTC

Prof, will all calculations can be done using calculators(by hand), or will there be qns where excel is needed ?

grade efficiency

2021-04-20 01:33:19 UTC

prof, is G(x) curve fixed for a particular type of cyclone no matter the particle sized distribution?

cyclones in series or parallel

2021-04-20 02:24:29 UTC

Prof, how do we know if to arrange the cyclnes in series or parallel, is it by their volumetric flow rate ?
do we by default choose parallel?

2021-04-20 13:31:34 UTC

seperators in series, do the Eu increase for subsequent cyclones? For each of these cyclones, the pressure drop is taken from the top to the bottom that cyclone only? Or does it include the pressure drop of previous cyclones above? Also, we will need to be given the individual pressure drop, V or Dcyc to calculate the final cut size correct?

Finals

2021-04-20 14:54:08 UTC

Hi prof, can I check if we are allowed to use tablets to refer to notes??

Crystallization Tutorial Qn2

2021-04-21 08:52:18 UTC

Hi Prof, may I ask when do we use the mass balance equations for solute and solvent? So far we have only used the combined equation without 𝜔_2. So we only use the main equations when we have the value for 𝜔₂?

Cyclones in series

2021-04-21 23:43:58 UTC

Prof, not sure if can ask this, but would we be tested on calculations for cyclones in series? There was no worked example so do we need to know?

cyclones

2021-04-22 06:45:43 UTC

prof, how to choose whether to arrange in parallel or series in a qn ? do I default choose parallel and calc like in tut?

Hi prof for the Cyclone Tutorial if I just set 2 equations- 1 for Stk50 and 1 for Eu and try to solve simultaneously for n and Dcyc I get the wrong answer. Could you please tell me why this method is wrong

2021-04-22 09:09:16 UTC

Cyclones practice qn

2021-04-24 06:26:44 UTC

Hi prof, do you have extra practice qns for cyclone? Or the qn in finals will be similar to that of tutorials?

Tutorial 8 qn3

2021-04-24 12:59:16 UTC

Prof, since we are not allowed to use excel, qns like tutorial 8 qn 3 unlikely to be tested?

Can use pencil?

2021-04-24 14:55:48 UTC

Hi prof, this might sound lame but can i ask if i can use pencil for the final exams. Cause your email didnt say so. Just checking cause i used pencil for finals before and got marks deducted cause prof wanted pen

Tutorial 8 Q3

2021-04-24 15:16:57 UTC

Prof for the last part of q3, the mean voidage we calculated is lower than the prev part when using larger particles and you wrote 'large particles expand less' but doesnt lower voidage mean that the particles take up more space so = particles expand more ?

Cyclone Preparation

2021-04-24 16:29:25 UTC

Hi Prof, how else can we prepare for Cyclone Chapter? Cause the tutorial was pretty much excel intensive, but the use of excel is not within the requirement of finals. I got still understand the tutorial but yeah just wondering if there's any other possible advice? thanks

Are the cyclones arranged in series or parallel assumed to be all identical?

2021-04-25 01:49:15 UTC

So we usually account eg Dcyc for just one cyclone in the arrangement and it will be the same for the rest?
In series arrangemnet, the Dcyc will be the same too for each and every cyclones?

prof, are the pressure drop across the 1st cyclone different from the 2nd cyclone arranged in series?

2021-04-25 01:56:58 UTC

So the Characteristic velocity are different for the 2 cyclones arranged in series?
The EU and STK no. is different for the 2 cyclones in series right?

Prof, do we always assume no evaporation of solvent when the qn didnt state the E? Like in tut 12 q1, we assumed E=0 & R=1

2021-04-25 03:18:29 UTC

Prof, will we be required to use the Bo eqn? Primary and sec nucleation?

2021-04-25 04:04:43 UTC

Request for midterm questions

2021-04-25 04:14:46 UTC

Hi Prof, is there by chance you have like the softcopy of the questions from midterm on packed beds and fluidized beds? cause i want to do them for practice purposes. we only have the solutions but its hard to check the solution without the question. Thanks

Prof, at Umf, do we alr actually consider the bed to be fluidized bed? or it is similar to pack bed still?

2021-04-25 05:27:33 UTC

For Feed distribution of cyclone if given the distribution of Coarse product and asked to find distribution of Fine product do we use the dF/dx= Et(dfc/dx)+(1-Et)dFf/dx equation or just mass balance based on dF/dx- dFc/dx

2021-04-25 12:06:33 UTC

2021-04-25 15:31:13 UTC

before finding distribution of fine product

Excel clarifications

2021-04-26 02:21:58 UTC

Hello Prof, can I clarify that excel is banned during the finals? Even to use goal seek to find values?

Thank you Professor!

2021-04-27 06:05:38 UTC

It was a rough sem but I throughly enjoyed it Prof! Hoping to have you as my profs for future semesters!