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 cowski 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. georgeverghese

    Dew point for RNG

    Most facilities / process engineers in the gas business should have a copy of the GPSA Handbook -see the chapter on Gas Dehydration where you will find the McKetta charts for water content of natural gas streams, covering pressures up to 10 000psia. At 4000psig, some extrapolation is required to...
  2. georgeverghese

    Real or ideal cp/cv for orifice sizing

    In all cases, it should be real gas isentropic exponent. There are pressure and temp ranges when real values approach ideal - see your thermo textbooks. Semi ideal and ideal values may be used as an approximation for low pressures, ambient temp ranges typically.
  3. georgeverghese

    U-bend before pump suction inlet.

    That is one way to keep the pump casing primed on shutdown, but I dont see a way to prime the suction riser going down to the cold well if it all dribbles out through a leaking foot valve.
  4. georgeverghese

    Wet scrubber - what happens if you continue to re-circulate a scrubbing liquid?

    Calcs I've done now tell me that at 50% DMF solution ( ie. 500grams DMF per litre of solution, assuming no volume change of mixing) the saturation ppmv for DMF in the vapor space is 2800ppmv at 40degC. ( H drops from 160 at 25degC to 48 at 40degC). So, in this batch mode 100% solvent recirc...
  5. georgeverghese

    Wet scrubber - what happens if you continue to re-circulate a scrubbing liquid?

    What are the units for your value of H? Compilation on the net tell me H at 298degK, 1 atm is 160gm moles/m3 of solution per 1Pa partial pressure of DMF in the vapor space, while d(ln H)/d(1/T) = 7500 (units in deg K) - does this match up with your value of H ? If you dont have the value of...
  6. georgeverghese

    Process Chill Water Loop for Multiple Machines with varying requirement.

    What about the pump performance - does it match the duty case Q- h requirement ? Ask a process engineer to sort this out for you. a) The "return line shutoff valve" can be replaced with a constant dP control loop, which should then act as a pump min flow control mechanism and provide a...
  7. georgeverghese

    TEMA DEU/CEU Heat Exchanger - Connection Challenges & Analysis

    If tube side fluid leakage to shellside is a significant safety or production related concern, then a double tubesheet may be used. Here, the tube bundle goes through 2 tubesheets in series. The interspace between the 2 tubesheets is operated at a pressure less than the min normal operating...
  8. georgeverghese

    Wet scrubber - what happens if you continue to re-circulate a scrubbing liquid?

    It depends on the gas flowrate and the number of NTUs' you have in this packed bed. Do you have this value for the NTUs' ( or some other similar data) for your column? Run the calcs for this with the expressions you find for rating packed beds in your chem engg textbook on mass transfer. For...
  9. georgeverghese

    TEMA DEU/CEU Heat Exchanger - Connection Challenges & Analysis

    Is there some key concern with tubeside to shellside leakage past tube to tube sheet joints in this case: "Exchanger Tubes: SAF 625 (Strength expanded and strength welded)" If it helps, at a considerable cost adder, use a double tubesheet.
  10. georgeverghese

    Wet scrubber - what happens if you continue to re-circulate a scrubbing liquid?

    Mass transfer is also affected when you have maldistribution of liquid over the cross section of the absorber column. The configuration of the first distributor, redistributors every several ft of length also are key factors, especially for packed bed units. Keep vapor velocity within...
  11. georgeverghese

    pumps

    It is very likely that you've got vapor carry under in to the suction line of P102 - this will result in reduced pumping capacity at P102 and erroneous readings from that flowmeter. Can you describe how this de aerator works ?
  12. georgeverghese

    Wet scrubber - what happens if you continue to re-circulate a scrubbing liquid?

    Agreed, it will stop absorbing when the recirc. absorbent liquid concentration reaches the Henry's Law limit at this operating temp
  13. georgeverghese

    pumps

    Is there some way of verifying if pump 101 is running at 4m3/hr and not 1.8m3/hr ?
  14. georgeverghese

    Plugging and wrong DP output

    Ask for remote seals on BOTH HP and LP sides of the dp cell - diaphragm seals - this should prevent any gunk / condensate from getting into the impulse lines.
  15. georgeverghese

    Compensating pressure in Cryogenic Storage Tank

    Adding on to Snickster's calcs, makeup vaporisation rate at external vaporiser for = 11.3kg/min. Heat of vaporisation for sat CO2 at Tsat = 242degK is = 300kJ/kg, which leads to a heating rate of 57kW. Add 10% design margin = 62kW. See if you have LP steam for this thermosyphon type heating...
  16. georgeverghese

    TEMA DEU/CEU Heat Exchanger - Connection Challenges & Analysis

    Hazop should have indicated that design T should be same on both sides. Design T should also state the range in temperatures from min design to max design for each side. Ask the plant operator what are the design cases for temp on both sides for diff thermal expansion consideration. Am not...
  17. georgeverghese

    Subject: Dyke Wall Capacity Criteria as per NFPA/OGRA – Class-wise Tank Scenarios in General Plot Plan

    While you may be blinkered on this task of determination of containment dyke volume, it should be obvious this is the final containment barrier in the event of a fire and tank rupture. There are many other prior safety / containment measures that must be implemented and maintained in order to...
  18. georgeverghese

    PSV Inlet and Outlet Pressure Drop Calculation Question

    Unless you have a unusually high dp on the exit line from the PSV, you get only a slightly lower predicted backpressure with adiabatic compressible flow expressions. In all cases, the isothermal approximation yields conservative results for developed backpressure. There is no harm in using the...
  19. georgeverghese

    Subject: Dyke Wall Capacity Criteria as per NFPA/OGRA – Class-wise Tank Scenarios in General Plot Plan

    See if this helps : especially para 5.8.2 discussing AS1940 requirements https://jyotisconsulting.com/wp-content/uploads/2020/10/Publication-Tank-Farm-Bund-Walls-Hydrocarbon-Processing-2006.pdf
  20. georgeverghese

    Cavitation while running 1 pump but not 2

    Do these pumps take suction through dedicated lines direct from the source expansion drum ? Could there be gas carry under through that first pump's feedline?

Part and Inventory Search

Back
Top