Pavan,
I think LI's point about pipe ordering means that you don't order pipe with a nominal size and a specified thickness (unless you want a horrendously expensive custom pipe). Instead, you get a minimum thickness from design equations, then find the next thickness up, and order that...
Think about it this way. Shear stress is proportional to the differential velocity as a function of r (the du/dy term). Microscopically, the shell is immobile, and the surface molecules of the shell are being "pulled" (or pushed, if you want to think about the layer-to-layer friction that way)...
Best case has a near 0-0 intercept on the green line (stress-shear curve). That tells me it's a standard shear thinning fluid (shear thinning due to the clear viscosity drop with shear rate. The worst case has a non-zero, but still small stress intercept near 15 ish Pa (this is called the yield...
Farmer,
There were two points to the exercise. Firstly, to get an idea of your flow profile shape. I think it's pretty clear that you have, as you initially suspected, a "pluglike" flow of faster core material with a shell of slow/sluggish material.
Secondly, for your worst case material, it...
Farmer,
Look to see my note above (Notation correction: In the last part of my prior post, the picture for velocity profile includes mu and K. The author of that paper denoted K as the dP/dz, and used mu for what I called "K". Just an FYI, as the math won't math out otherwise. If you know what...
Notation correction: In the last part of my prior post, the picture for velocity profile includes mu and K. The author of that paper denoted K as the dP/dz, and used mu for what I called "K". Just an FYI, as the math won't math out otherwise. If you know what pressure drop you are getting...
Also, if you do the steps above, make sure to graph velocity, v, versus r (distance from center). This will give you a velocity profile in your pipe. Give the extreme shear-thinning nature here, I would expect to see velocity drop off from the center and very quickly approach 0.
You won't ever...
OP, since you have a rheology profile for your liquid, follow the below steps to get an equation that describes your fluid. Based on your graph, I would say your material is simply shear thinning, not a Bingham plastic, though starting out at a really high 0-shear of >1,000,000 cP.
Ostwald-de...
To be honest, the only time I've seen UA calculated as a whole unit is on existing heat exchangers where you need to track fouling over time. Since the A is fixed, you don't really need to look up the area on each individual heat exchanger. Instead, you divide the heat load by the LMTD to get...
I think OP means chlorine gas, which can indeed permeate through PTFE material. The mechanism by which this occurs is periodic substitution of a F with a Cl on the polymer chain. Though F affinity is higher, it can be substituted by a Cl. Since F affinity is higher, it will return to kick the Cl...
Firstly, thank you for all the help you’ve given thus far. I am sorry for the continued questions, but my company doesn’t have any experience with these types of alloys, so I am having to rely on senior Google and helpful strangers like yourself.
(Edit: Answered my own question. Found out...
I'll bring them out for good in 1 week and rinse/clean. This was a 1-week visual inspection made just due to the change in hue of some of the samples. We measured 4-point thickness on corners and also the weight before the test, so I'll be able to tell any thickness changes from corrosion and...
FYI we performed some initial corrosion tests in the lab with a few materials. In order of the pictures below, they are 2205, Alloy 20, and C276. This is 1-week of immersion under flowing conditions.
Also FYI, the pH condition of the material was 0.8, not 4.
It's quite obvious that C276 has...
Thermowell projection into the stream is usually minimized if flow velocity is high (due to very long well length). Due to the inherently long thermowell, pay particular attention to vortex-induced vibrations and the resonant frequency of the thermowell. This will likely set your maximal...
Having not spec'd a vessel for corrosive service before, what would typical specifications before for welding for corrosive environments? I assume there would be a limit on heat to limit the HAZ as well as certain cleanliness requirements, but haven't really delved into this area before.
Ed,
This is a developing process through R&D at the moment, so I don't have the exact pH. Given the nature of some of the reactants, I would expect a final pH of near 4 to be required as a starting baseline. Would going lower change material selection from C276 to something else?
How do...
I have a potential small reactor design that will alternate between high pH (10% by weigh NaOH, so 14+ pH) that is later taken to a slightly acidic side with HCl, resulting in a 6-10% salt (NaCl) solution. The reactor temperature will be ambient, so no high temp conditions. I've reviewed some...
Typically the Cv listed on the valve body and datasheet will be the 100% open Cv. A Cv of 0.4 does not sound oversized to me - an equal % CV will get down to 0.1 Cv around 60-70%, while a linear CV will likely be near 30% open to get a Cv of 0.11. In either case, the valve seems sized...
