Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

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

Recent content by Rosalynn

  1. Rosalynn

    What's better for heating/cooling? DEG or TEG?

    Our minimum design operating pressure is 350 kPag (51 psig). This is in our surge drum, which operates at 40C and 350-500 kPa (the pressure is controlled by supply and bleed pressure regulators on the vapour space, using natural gas to blanket the vessel). The hot glycol headers are on the...
  2. Rosalynn

    What's better for heating/cooling? DEG or TEG?

    Hi, Andrew The maximum design bulk process temperature the glycol will see is 140C, in one heat exchanger. This exchanger is in parallel with several other exchangers, all operating at lower temperatures. The hot glycol return header will operate at 100-110C. The plant design currently...
  3. Rosalynn

    What's better for heating/cooling? DEG or TEG?

    Hi, Andrew The maximum process side temperature I have is 140C, in one exchanger in the plant. All others are 130C or less. Based on this, EG/DEG are candidates--please let me know if you disagree. I hadn't considered EG, but I will now--thanks. (I've heard in the past that EG's vapour...
  4. Rosalynn

    What's better for heating/cooling? DEG or TEG?

    Dear Yorkman, Propylene glycol doesn't quite have the thermal stability we need. While toxicity is important, the application is for the oil industry. Proper controls will be in place to minimize leaks and spills and for their mitigation if they occur. You're on TV? Cool. Thanks for the...
  5. Rosalynn

    What's better for heating/cooling? DEG or TEG?

    My past experience is with DEG/Water solutions for mild heating/cooling applications (40 deg C-150 deg C temperature range). However, many of my colleagues in my new place of work have experience only with TEG/Water solutions for these services. They say it's better because it's more stable at...
  6. Rosalynn

    Vessel Code?

    Hello, If ASME B31.3 applies to your jurisdition, this may be more appropriate for your device. It sounds to me more like a piping component than a vessel. If the individual components used are in compliance with B31.3, and they are assembled in compliance with B31.3, then you've got a pretty...
  7. Rosalynn

    Crude Flashing ok in S&T?

    Thanks to both Montemayor and J. Alvarez. Input much appreciated, and will keep all points in mind as I move forward. Regards, R
  8. Rosalynn

    Crude Flashing ok in S&T?

    The existing preheat train first heats the crude (enters at 80C or so) with a side draw (VGO at about 200C) from the asphalt column. Then the feed is further heated with the asphalt from the bottom of the asphalt stripper (300+C). The LMTD's in these exchangers are in the 70-80C range. The...
  9. Rosalynn

    Crude Flashing ok in S&T?

    I have a project to increase the throughput in an asphalt plant. One of my ideas is to increase the temperature entering the first flash vessel in the unit, by making the feed/preheat train more efficient. There is no fired heater upstream of the first flash vessel and to keep op costs and cap...
  10. Rosalynn

    Heat Trace Spill Tray Design Rules of Thumb?

    This is info for Isofilm, regarding the PQ curve for the glycol pump. The tracing for the spill tray will be part of a larger heat tracing network in the plant. The pumps deadhead at 350 ft of TDH and pump from a suction tank kept at 11 psig. The operating point on the curve is at 1633 USGPM...
  11. Rosalynn

    Heat Trace Spill Tray Design Rules of Thumb?

    D'oh! Sounds like what's called a pump curve around here. Ok, I'm going to the site this coming week. Will get the PQ curve and report the pertinent details asap. Thanks, R
  12. Rosalynn

    Heat Trace Spill Tray Design Rules of Thumb?

    Thanks isofilm, I'll check into FOAMGLAS. Hadn't heard of it before. Sorry, what's a PQ curve? I'm not familiar with that term. I believe that the glycol supply temperature is 70C, but need to confirm this (it may be a bit hotter); the geographical location is northern Alberta. Regards...
  13. Rosalynn

    Heat Trace Spill Tray Design Rules of Thumb?

    I need to heat trace a spill collection device to prevent icing up in winter. The heat medium is glycol/water; I'll find out the flow rate and supply temperature next week. The tracing will likely be laid in 2" of light-weight concrete, with the spill tray (steel) laid on top of that. My hokey...
  14. Rosalynn

    Why do balloons hit a wall of air?

    To wilg: You've given me a lot to think about. I even got out my old text book from school to look up drag coefficients as a result of seeing the Malewicki equation. Thanks! For now, I think I'll take a pass on the "coast" equation--it probably doesn't have a term for exerting the...
  15. Rosalynn

    Why do balloons hit a wall of air?

    I have read everybody's answers with interest. wilg and MintJulep came the closest to answering the question I thought I had asked. Thanks, guys! To wilg, regarding the Altitude Prediction chart equation: This looks really good. Are the units SI, metric, or Imperial? I'm assuming V is...

Part and Inventory Search