it would be extremely helpful if you would include the units on the number. nevertheless, kudos!
@marsogreen24118 күн бұрын
Thank you for the video. For known/common material such as wood, mulch, wood chips, saw dust, milk powder, etc., are there published tables that approximate the critical point for the material? Wouldn't such data be useful as a starting point before embarking on experiments for system/energy optimization, or would that be inadvisable? Thanks in advance
@marsogreen241111 күн бұрын
Thank you for posting this lesson. Question: Any reason why one cannot condense the moisture out of the outgoing wet air at optimal (highest possible) temperature (as long as it's above ambient), and add only a small amount of ambient to replace lost air volume (due to the lower temp) by introducing a small sized air inlet in the ducting, which would essentially provide pressure equalization and small ambient air draw into the system?
@syedajmal5076Ай бұрын
Thank you sir!!
@rafilkhairullin3130Ай бұрын
Thanks for the great explanation, very helpful!
@nooshin3928Ай бұрын
stupid
@ClaireGlasgowАй бұрын
Where is the feed ratio specified
@PLE_LUАй бұрын
Channel moderator here: At 6:02 the text states "if the molar input of O2 is three times larger than the molar input of CH2O"…
@TangMinhHung2 ай бұрын
Thank you! but how do I comment on the adsorption process from the adsorption isotherm?
@SanjayYadav-fy4dg2 ай бұрын
Which software are you using?
@PLE_LU2 ай бұрын
The programming environment used here happens to be Anaconda with Spyder, but you can code and execute Python code using various other programming environments
@SanjayYadav-fy4dg2 ай бұрын
@@PLE_LU i want to learn evaporation sizing through this software, will you help me ?
@PLE_LU2 ай бұрын
1. Python is a programming language, not a software. What we demonstrate in this video is _one_ way to solve a set of non-linear of equations 2. The course this video is a part of is not a MOOC (Massive Online Open Course), we just make the videos we use in the course available to the world in the hope they might help more people than just our students. We cannot offer individual support outside of our courses.
@hamidboleydei2 ай бұрын
A quick question: When the saturation takes time, and I need to run column experiments for days, is it ok to stop the pump at the end of each day and start it to continue the experiments and sampling the next day?
@PLE_LU2 ай бұрын
I don't think there is a general answer to that question. There might be situations where it is ok, but if you stop the pump diffusion will continue and thus broadening of the front may be substantial. Also, as soon as you change operating conditions in a real life case, all bets are off. The only way to be sure if a change matters is to test if it matters
@hamidboleydei2 ай бұрын
@@PLE_LU thanks a lot for your reply. Appreciate it :)
@maiky58155 ай бұрын
great video thank you so much
@omidmosallanezhad31975 ай бұрын
it is a great explanation of the graphs and well understood presentation. thanks a lot.
@malikhassamzahid63016 ай бұрын
Can you share your LinkedIn profile, how can I contact you.?
@TobiasSchauer6 ай бұрын
why is Rmin 0,76?
@oxycope88216 ай бұрын
You are a fantastic teacher! Very happy that I came across these videos
@thescientist18396 ай бұрын
Whatever be the name. Lund university faculties are really talented.
@sarimiari94507 ай бұрын
Thanks for showing how to calculate Rm, unfortunately my prof did not explain it on a graph but only said that Rm=(L/V)min so I was confused and lost. Turns out it is very simple
@shnoalimhamadkaram15947 ай бұрын
Hi sir ,the explanatian is very amazing ,but generaly l do not know a thing ,when you wanna draw the trigonal between operating and equilibrium cerve if you draw large trigonal you will get a few amount of number of the tray but if you draw the trigonal by the small way you will get a more number of the trays , please explain for me how can l draw the trigonal😪
@PLE_LU7 ай бұрын
I don't think I understand your question. Drawing these lines between the operating lines and the equilibrium curve is analogous to alternating between solving a mass balance and solving the equation for the equilibrium between the phases. Please note that there is a newer playlist on distillation: kzbin.info/aero/PLvpgTFzUKO49J3fwJF9y61q17FSNDdoGN
@Gealamusic7 ай бұрын
Thank you
@Caillou3157 ай бұрын
Thanks for the video it was helpful. Greetings from Germany THM biotechnology 😅
@99Gara998 ай бұрын
Thank you. This is how people should teach things. Straight to the point.
@hamidboleydei8 ай бұрын
This sir's knowledge and experience is awesome and so helpful. Please give him my regards!
@jeromenuevo16278 ай бұрын
What parameters would you examine in point 3 to obtain the psychrometric properties if it's based on actual conditions without assuming 100% relative humidity?
@PLE_LU8 ай бұрын
Level 1 answer: Measure one more thing, e.g. the temperature in flow 3 Level 2 answer: In a real system, the dryer is never fully adiabatic, so measure both temperature and wet temperature in flow 3. Level 3 answer: In a real system you typically want your drying goods to become dry, right? So the underlying assumption that the drying goods is surface wet is violated and the air in the dryer will not follow the adiabatic cooling line and thus you definitely need to measure both the temperature and the wet temperature in flow 3. Compare the video on drying rate: kzbin.info/www/bejne/hKnaZ4Wbpb2qrdk
@jeromenuevo16278 ай бұрын
@@PLE_LU Thank you for your quick response. Btw, I’m currently designing a dryer for my undergraduate thesis and there’s no possible way to measure the temperature at point 3. What should I do to determine the properties at point 3?
@MostafaMASLOUHI8 ай бұрын
Thank you so much. I have looking for this and no one talk about this as you did.
@PLE_LU8 ай бұрын
Glad that it helped. My guess is that most mathematicians would dislike this video as I am not mathematically rigorous in the explanation 🙂
@minhduong38818 ай бұрын
May I ask how can u do it without an equilibrium line ? or how to graph an equilibrium graph ?
@PLE_LU8 ай бұрын
You need the equilibrium line. You can either interpolate from literature data, or use one of many "curve fits" (in which case you need literature data for the parameters). What curve fit to use depend on the system, van Laar is one of those "curve fits". Compare the video studio.kzbin.infolz-RWsMYx48/edit which explains how you can take the first steps if the system is ideal (which is usually never true). From there you have to find ways to calculate activity coefficients (using e.g. van Laar).
@minhduong38818 ай бұрын
@@PLE_LU Thank you for the advice .
@mohammadmoradi44688 ай бұрын
best of the bests
@karolinahagegard8 ай бұрын
This is lovely, but there's one thing I have to tell you: Only Swedes would ever talk about "moist air"... 😏 The term in English is "humid air"!
@PLE_LU8 ай бұрын
Thanks for the hint, but you are actually incorrect. The probably most common engineering way to express this is still _moist_ air, see e.g. www.engineeringtoolbox.com/moist-air-properties-d_1256.html So, in engineering we talk about moist air versus dry air. Moisture content = kg water/kg dry air, Relative humidity compares the humidity with the moisture content at saturation. How much the terminology varies between countries is beyond my knowledge, but moist air is definitely commonly used in engineering contexts.
@justsomeguy29189 ай бұрын
Doing mechanical engineering, thank you for your video
@rezakhanbani9 ай бұрын
wow i am just speechless about how many things we should have considered but the professor never told us to
@PLE_LU9 ай бұрын
Hi, maker of the video here: There is a more recent version of this video if you are interested (kzbin.info/www/bejne/b5i9lpmqirOYoM0) and we do have a playlist on distillation Regarding what we teachers don't mention, I often say to my students "Nature is a bitch" as a short for "reality is usually way more complicated than our models of reality". Deciding what to not mention and how drastic simplifications to make when designing a course is a rather tough task. Jack Cohen and Ian Stewart describes this kind of problem in the drastic term "Lie-to-children" (en.wikipedia.org/wiki/Lie-to-children), a term I personally came across when reading the book "The science of Discworld" that they co-authored with late fantasy writer Terry Pratchett. Other famous quotes on this topic include "The best material model of a cat is another, or preferably the same, cat" (Norbert Wiener) and "All models are wrong. Some models are useful" (G E P Box). Let me take two examples: Should we include in our teaching that the Celsius scale was redefined in 1990 (ITS-90) or that the SI-unit system was redesigned in 2019? Both these facts have interesting consequences for how we do science, but with the limited time we have in a specific course, it might not be the most important for the student to understand. And just a final example, since this is a topic that fascinates me: I recently went through all chemistry text books in our local university library. All but one had an incorrect definition of reaction rate. They define it as a change in concentration over time. You find the same definition all over the internet and in all kinds of books. Even IUPAC (goldbook.iupac.org/terms/view/R05156) states that this is the definition. That does not, however, make the definition correct. In fact rather than a definition, that the reaction rate _equals_ the time derivative of concentration is what you get if all of the following criteria are met * You have only one reaction * That reaction is irreversible * You have a closed system * The volume is constant over time If any of the criteria are not valid, the reaction rate does not equal the time derivative of concentration. If you compress air, the concentration of air molecules increases (PV=nRT => C=n/V=P/RT), but there is no reaction. If you add more water to salt solution, the concentration decreases, but there is no reaction. The oxygen level in the blood of your brain needs to stay fairly constant (the time derivative of concentration being essentially zero) for you to survive, but there is a reaction consuming oxygen. If that reaction stops, you die. Nearly all naturally occurring systems are flow systems and the so called definition of reaction rate that is used by almost everyone is obviously invalid in such systems. Yet the faulty definition is still used and taught and will continue to be used and taught because it is easier to explain for beginners. I myself often say "my jacket is warm" although that's physically incorrect. The correct term is that my jacket is a good insulator. Sorry, went of on a tangent here :D
@ThanushaS-p3i9 ай бұрын
thank you so much ............!!
@noopurkatiyar27139 ай бұрын
Is lignin comes under carbohydrate polymer
@PLE_LU9 ай бұрын
Editor here: Depends on your definition of "polymer". Lignin is a complex substance, see e.g. en.wikipedia.org/wiki/Lignin
@maowtis9 ай бұрын
thank you so much. Love the examples and explanation. helped me get a basic understanding of DOF’s
@PLE_LU9 ай бұрын
There is more on DoF in the playlist kzbin.info/aero/PLvpgTFzUKO48fgoP6fVAYoDJjsCeuoITr in case you're interested
@dalsenov10 ай бұрын
Very informative and useful information!
@dr.markevers833110 ай бұрын
There is an easier way now (As of Feb 2024!) :-): Download a csv file showing the Group information within a group set: In your course, click People. Click the tab of the group set that you want to download the groups' information. Click + Import on the top right. Click the Download Course Roster CSV link to download the list. Click X on the top right to return to the Canvas interface.
@evazhang323210 ай бұрын
Good day, Professor: I have some questions concerning the property of hygroscopics. I found some contradictions between hygroscopic and less or nonhygroscopicity for the same substance. later on, I realized they are in a different form. one is in crystalline form but another is in powder form. Please forgive me for the potentially confusing terms. for the same substance, for example, D-mannitol. when does it have the property of hygroscopicity and when does it have the property of nonhygroscopicity? Thank you!!!
@PLE_LU10 ай бұрын
This video is about the very basics of hygroscopic materials and simplifies in that it divides materials into two distinct categories: hygroscopic materials and non-hygroscopic materials. In reality, the line between the two categories is blurred. As usual, reality is more complex than our models of reality
@evazhang323210 ай бұрын
@@PLE_LU Thank you so much for the reply. Do you have any recommendation websites or public resources that can find info on the properties of hygroscopic of certain substances? like chemical property info in general. I have found sits that list detail info for melting point boling point, but not its hygroscopic info. does hygroscopic is a general property of a substance? or its a phenonmenon will change according to varies condition?
@PLE_LU10 ай бұрын
Sorry, I have no good further reading hints apart from that there is information sprinkled in various standard chemical engineering text books. Just to mention one thing, if you have substances that different form of crystals with varying amount of crystal water, you can get behaviour that definitely isn't covered in this video. You can also compare with pF curves for soil, i.e. how much negative pressure you need to apply to suck water out of soil at varying moisture levels. Soil also typically has a moisture threshold under which the structure changes turning it hydrofobic (which you might experience if you forget to water your indoor plants for too long.
@evazhang323210 ай бұрын
@@PLE_LU THANK YOU!!!
@saeedulhassan365511 ай бұрын
really interesting concept
@rachelhobbs618911 ай бұрын
Thank you so much, applied math student here! This was really helpful for my thesis
@ALAN-ig2cu Жыл бұрын
very clear, helpful!
@sayit12345 Жыл бұрын
this video will might help me to give me to understand about membrane tech at Lund, i wanna be a part of membrane Group at LUND through MESD...it's my passion to learn about membrane processing for water filtration.😊
@hassan21995 Жыл бұрын
very interesting with clear explanations.
@galyagonzalez9645 Жыл бұрын
It's been 5 years is their publication out?
@PLE_LU Жыл бұрын
Yes, findings have been published and doctoral thesis defended. See portal.research.lu.se/en/persons/alexander-betsholtz/publications/
@menglimarrero4296 Жыл бұрын
Nice video Let me ask sir What chart did you use?
@PLE_LU Жыл бұрын
A Mollier diagram for moist air. There are two competing conventions regarding in which direction to draw the axes, if that's what you're asking. If you're asking who wrote the code for drawing this particular copy of this variant of a Mollier diagram, the simple answer is: I did.
@Ali-hw8pc Жыл бұрын
Tack så mycket det här hjälpte väldigt mycket 😊❤
@whogashaga666 Жыл бұрын
Thanks for sharing this video, so so so useful.
@Khizar_Ansari Жыл бұрын
These notations are confusing. If Ntot is total mass transfer then what is NA?
@mattiasalveteg8797 Жыл бұрын
The notation predates the change in the SI-unit system where N_A nowadays should always be Avogadro's number. Here N_A is the total mass transfer OF SUBSTANCE A, i.e. the sum of convective and diffusive transport. As most introductory texts/books/videos on mass transfer it is assumed that we have binary systems, i.e. only two components (A and B). When you introduce a third or more components it gets a bit more complicated.
@joansneijder6764 Жыл бұрын
Holy Mother of God. This is by far the best explanation I've seen of this concept. Thank You.