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  1. gedomin

    Rock salt specification for kerosene dryer filter

    Would appreciate, can somebody tell me what is the proper mesh size for the rock salt loaded into a kerosene/jet fuel dryer filter.
  2. gedomin

    Catalytic reforming unit

    One could ask: Was your primary coke burn interrupted and re-ignited?... one or more times? You could also check for catalyst channeling by analyzing reactor TI plot readings vrs time, during the coke burn. Compare last regeneration burn pattern with those of previous regens.
  3. gedomin

    Heat exchanger leak

    Sounds like a typical "Safety in Design" issue. A way for releiving liquid expansion must be insured. A PRV or procedural. This last at low or no cost. Procedure must instruct to ALWAYS leave a pathway (be specific) via one of the block valves, left open, for expansion relief. Install a...
  4. gedomin

    Stage Efficiency VS Overhead Vapor Fraction

    As a general practice, condenser efficiency shoud not be set different to 1, as it is a flash operation (V/L equilibrium). The problem you are finding is just as expected. As far as I know, experts prefer not using tray individual efficiencies. Better to set your model on theo trays. No. of theo...
  5. gedomin

    Octane barrel calc

    Linear programming tools help to obtain value of incremental qualities. PIMS from AspenTech is a powerful stuff... setting up your model is a pretty challenging exercise.
  6. gedomin

    how to calculate standard liquid flow rate

    Standard liquid flow is commonly understood at 60 degF and low pressure. From "Data Book on Hydrocarbons", page 145, we find a chart with a family of curves. Thermal expansion coefficient depends on molal average boiling point. You divide actual flow over expansion coefficient to obtain flow...
  7. gedomin

    Doppler type flow meter for saturated steam

    Has anybody experience or know about a supplier of a Doppler type flow meter for saturated steam ?
  8. gedomin

    Asphalt penetration

    Crudes detailed below seem best suitable for making asphalt. As you may note, cut points are beyond 700F, which indicates you must feed your topped crude into vacuum distillation. Cold Lake looks best. Residua converged to 290pen@25C Crude/Cut point degF/Yield on Crude vol%/Visc cSt@100C Bow...
  9. gedomin

    Asphalt penetration

    As said before, this is highly dependent on crude, depending on asphaltenes content. For low asphaltenes content, you might get no asphalt specs at all, even at high flash zone temps. May I ask what is the typical crude you are processing?
  10. gedomin

    Asphalt penetration

    Viscosity range ? You say Flash Point LESS than 270 degC. It shouldn't be an issue. How to predict Viscosity and Penetration vrs distillation cut point? These are highly dependent on crude type. Crude assay or actual plant data are required for estimating target distillation cut points. Wonder...
  11. gedomin

    Vac Resid Pipe Spec

    Last year story: An incident at a refinery, in California... Loss of containment. Cause was a pipe section of wrong material at a Vacuum Pipestill bottom. Upon investigation, a CS section was found installed by mistake, where proper alloy should be Cr-Mo (maybe 1.25/0.5 or higher). Material...
  12. gedomin

    Attachment of gaskets

    Current practice in my site is to stick a few pieces of scotch tape, radially, along the whole flange face, and over the gasket... Cut long enough pieces of tape. Clock reference: stick one piece of tape at 12, other sticks at 9 and at 3 if necessary. The same kind of tape you use for gift...
  13. gedomin

    Coriolis meter in Demin Regeneration

    We test the density reading by injecting fresh water for a while. Water temp = typicaly 30F. Expected reading should be very close to 1. This is our reference for setting a correction factor, in the DCS. Correction factor option was cheaper than running a rigorous calibration of the meter...
  14. gedomin

    Coriolis meter in Demin Regeneration

    I installed a Coriolis meter for measuring NaOH injection into a caustic wash system. It works fairly OK. The solution density-concentration curve is in the process computer, so operators set the injection rate in lbs/hr of pure chemical NaOH. A Math block translate flow and density readings...
  15. gedomin

    Fire PSV for PHE' s

    Gaskets are specified depending upon process conditions. Catastrophes shall be focused separately. PR devices have nothing to do with gasket selection. To mention: Important consideration in plant design is equipment spacing. It has to do with fire events. Oil industries have their standards...
  16. gedomin

    Fire PSV for PHE' s

    As far as I know, the contingency of a fire is not commonly the governing case for pressure relief analysis in heat exchangers, as is the case for vessels with important holdup volume, specially vaporizing liquid. Normal flow piping can provide an escape route for some contingencies, including...
  17. gedomin

    Conversion of Flow Transimitters Signals to Volumetric Readings

    Orifice meter output must be scaled into square root. Example: Flow span from 0 to 1000 gpm, and differential pressure span from 0 to 100 in H2O. 49 in H2O differential pressure corresponds to sqrt(49/100)*1000 = 700 gpm. During the pen recorders era, this reading was close to the center, at 49%...
  18. gedomin

    Hot Pinch and Cold Pinch

    Heat transfer is limited by either: T1-t2 (hot end) or T2-t1 (cold end). Say hot pinch and cold pinch, or temperature approach. T1 = Hot inlet temp T2 = Hot outlet temp t1 = cold inlet temp t2 = cold outlet temp Assume you are dealing with single phase on both sides If you try to design for a...
  19. gedomin

    Safe operating conditions for Autorefrigeration potential

    The contingency that governs is any leak of product to the atmosphere. Local temperature could potentially reach product boiling point. For the case of pure propane this is -43.8 degF (minus 43.8), at sea level.
  20. gedomin

    KEROSENE/ LIGHT DIESEL

    It seems your degree of fractionation is like typical for 5 or 6 actual trays between cuts. You can check against simulations. You've got to determine actual cut point between cuts, in order to set your running plans.
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