Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. TiCl4

    Free Vent for API 650 Tank - Bug Screen / Bird Screen Requirement

    To LI's point, I have specified bird screens in the past, with ~1-2" diamond mesh screens. Going small diameter for a "bug" mesh (<0.25"?) does seem like a good recipe to get clogged with dirt or even just rust.
  2. TiCl4

    Free Vent for API 650 Tank - Bug Screen / Bird Screen Requirement

    Cab, In the past, I have gone with option 2A you presented - increase opening size until actual free area >=required free area. I don't know of any available correlations for pressure drop through a bird mesh, but your number of 50% area reduction seems reasonable. I seem to remember the mesh I...
  3. TiCl4

    Control Valve Pressure Survey

    Shvet is correct - Cv for control valves is calculated based on permanent pressure loss. If your taps are too close to outlet of the valve, you will be seeing a pressure drop that includes both permanent and recoverable pressure drop. Note that this arrangement is different that orifice flow...
  4. TiCl4

    Non-Newtonian fluid ratholing

    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)...
  5. TiCl4

    Non-Newtonian fluid ratholing

    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...
  6. TiCl4

    Non-Newtonian fluid ratholing

    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...
  7. TiCl4

    Non-Newtonian fluid ratholing

    You have an actual pressure drop of 1.5 bar per meter of pipe?
  8. TiCl4

    Non-Newtonian fluid ratholing

    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...
  9. TiCl4

    Non-Newtonian fluid ratholing

    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...
  10. TiCl4

    Non-Newtonian fluid ratholing

    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...
  11. TiCl4

    Non-Newtonian fluid ratholing

    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...
  12. TiCl4

    Heat Exchanger UA value - Query

    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...
  13. TiCl4

    chloride diffusion in ptfe vs eptfe

    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...
  14. TiCl4

    Thermowell in refratory

    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...
  15. TiCl4

    liquid butane flow control

    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...
  16. TiCl4

    liquid butane flow control

    Good point. What is the normal operating % of the control valve, and what is the CV value at 100% open? My rough math on this: 0.05 kg/s -> 1.3 gpm (s.g. of liq butane at 0.6). dP = 85 psig, maybe take 5 psig away from line losses = 80 psig. Q = Cv * (dP/s.g.)^0.5, estimated Cv = 0.11 I would...
  17. TiCl4

    liquid butane flow control

    There might be a few issues with the following solution, but this might be your best "cheap" try at fixing this: Put a restriction orifice in the line directly on the reactor inlet nozzle. Size this such that the majority of your pressure drop occurs through the orifice, not in the CV...
  18. TiCl4

    Hello, good time I want to convert

    Do you want the plant layout, isometrics, controls software setup, and fully trained operators supplied as well? Eng-tips isn't a place for free design and for others to do your job for you. Get out of here.
  19. TiCl4

    Centrifugal Pump Shear Rate Estimation?

    Thanks for the input all. Our vendor suggested Discflo as an option, but cautioned that motor HP will be much higher (lower efficiency, I guess). The current pump isan APT-33 with what is called a "special open" impeller. I'm not sure that extreme measures for low-shear are necessary, as this...
  20. TiCl4

    Centrifugal Pump Shear Rate Estimation?

    Ed, I had wondered if impeller tip speed was the most critical factor, but I admit some ignorance as to the design of centrifugal pump internals; for example, I know that they have some level of internal recirculation flow while operating, but don't know if different levels of internal recirc...

Part and Inventory Search

Back
Top