Pour point, as any cold property, is difficult to estimate because it depends more in feed composition than in any other parameter.
For flash point, you can use the API correlations or many others . Basically it depends in the lighter side of the distillation curve 10%_ASTM (light-end...
Could anyone tell me the UK/USA laws which regulate the occupation as chemical engineer? I refer to those laws which list all the competences and professional skills that are associated to a chemical engineer. Internet links are welcome. Thanks in advance
Hanon
Maybe you have a flooded wash bed due to coke accumulation during this run. It could be possible according to such a high dP compared to design. Try to do a pressure profile along the tower to see where the problems are located. If you have internal levels in the tower be aware of them: maybe...
Maybe you want to have a look to this paper "Four steps solve crude-tower overhead corrosion problems" by Lieberman
It quite useful for your case
Regards,
Hanon
If the steam condensates inside the exchanger you could laminate in a the pressure control valve to 13 barg because you will have almost the same heating power indepently of the inlet pressure. The main source of enthalpy is during condensation.
Otherwise if you try to use 17 barg you will have...
I have the rough idea (not confirmed) that an overflow weir is used to get a better water-hydrocarbon separation because the residence time is bigger in the water part and both liquid have more time to separte. So, an overflow weir is used (I think) when you need a high residence time in the...
These eyetors are located in the top part of a vacuum unit. The load is basically constant independently of using one or both in parallel. The parallel eyector was installed in a revamp of the unit but it has never got to work toghether with the high capacity one. The condensers are working...
May two parallel steam ejectors work properly in a Vacuum unit? The system consists of three pairs of 2 parallels ejector. Each stage is compounded by a common pipe which is divided into two ejectors. The discharges of both are again mixed and go to the condenser of this stage. It can not be ran...
I use the Chen equation which give explicitally the friction factor. I quite useful because it gives directly the friction factor for a given Reynold number without having to iterate as happen in other correlations which are implicit.
Regards, Hanon
The correction in Hydrocarbon densities as consecuence of density is collected in API 1250. It give you the mathematical formula to get the right density at the working temperature and at 15ºC. You can find it via google
Regards,
Hanon
Level control is fundamental. In my experience, bad level control is the main source inestabilities and global oscillation of a plant. A level bad tuned can make the plant to oscillate entirely. It should be tuned mayority as proporcional PID with huge integral time to avoid cycling. In your...
The sump is at the bottom of a central downcomer. Tower diameter = 2300 mm and tray spacing = 610 mm. For the design flow (around 30 m3/h) and taking into account 50% of downcomer volume the residence time is 30 secs., closer to the recommendation.
In other hand I have read that typical...
Residence time of about 1 minute is huge for a partial draw-off. The current sump was designed for a calculated residence time of 2.6 sec.!! ( is a box of 250x300x320 mm for design flows of about 30 m3/h). To satisfy this design criteria we should make a huge sump!. I will try to get Kister´s...
To predict the flow regime you can use the Baker correlation / chart that are available in many fluid books (for example in Practical Process Enginerring by Sandler & Luckiewicz ), and to estimate the pressure drop use the Lockart-Martinelli charts. Slug flow, as far as I know, is undesiderable...
The 90 m3/h is supposed to be the flowrate at liquid condition ( 56000 Kg/h with 630 Kg/m3 at P,T ) We don´t measure it because these conditions are for the future project. Currently our maximun tested draw-off flowrate is 60 m3/h measured at P,T : 1.4 Kg/cm2, 150 ºC). We can not try a test to...
Sorry for the writting error. The right conversion is 1.4 m/s = 4.66 ft/s instead of the previous 3.66. It was a numeric typing error. The calculation dH = 0.34·V^2 = 7.38" = 188 mm was right. Where can I find references about the minimmun residence time to V/L disengagement that you suggest. I...
I make an auto-answer. I got the API correlation (1997 version)
Close cup: FP = 0.69*T_10%_D86 - 118.2
Open cup : FP = 0.68*T_10%_D86 - 109.6
FP: flash point , ºF
T_10%_D86 : ASTM D86 10% tempearature , ºF
Thanks for your help. The actual pipe is 6" and we want to extract through the nozzle heavy naphta at 150ºC a 1.4 Kg/cm2 . I am not afraid for NPSH problems because the draw-off is located 20 meter above the pump. Q = 90.8 m3/h --> V = 1.4 m/s = 3.66 ft/s
I have used two correlations from...
We are trying to revamp a tower and as a result of this changes a high flow increase in a partial draw-off is required. I am interested in any correlation to predict a safe height to prevent flashing in the nozzle. Xurrently we are operating with 40 m3/h and a draw-off height of 220 mm but we...
