Having not spec'd a vessel for corrosive service before, what would typical specifications before for welding for corrosive environments? I assume there would be a limit on heat to limit the HAZ as well as certain cleanliness requirements, but haven't really delved into this area before.
Ed,
This is a developing process through R&D at the moment, so I don't have the exact pH. Given the nature of some of the reactants, I would expect a final pH of near 4 to be required as a starting baseline. Would going lower change material selection from C276 to something else?
How do...
I have a potential small reactor design that will alternate between high pH (10% by weigh NaOH, so 14+ pH) that is later taken to a slightly acidic side with HCl, resulting in a 6-10% salt (NaCl) solution. The reactor temperature will be ambient, so no high temp conditions. I've reviewed some...
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...
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...
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...
Your gc is wrong.
gc is functionally unitless. However, gc in imperial units is 32.2 (lbm*ft)/(lbf*s^2). gc in metric is 1 kg*m/N*s^2.
F = m*a, right? No, F = m*a/gc.
In metric, this means 9.81N = 1 kg * 9.81 m/s2
However, in Imperial units, 1lbm * 32.2 ft/s^2 = 32.2 lbm*ft/s^2. For whatever...
Because density is a function of molecular weight of the gas flowing through the meter as well, which is the crux of your issue. Density is a function of both pressure and molecular weight. Ideal gas: rho = P*(M.W.)/ (R*T).
Please explain your reasoning. Coriolis meters are good for gas flow, and are perfect for your application, as they can be used to directly measure volumetric flow rate. E&H E300, a middle-of-the-line model, has a +/- 0.5% error on gas mass flow, and a decent range on allowable gas velocity. The...
As an addendum, would UG-80 requirements for out-of-roundness come into play here? If a FEA analysis, as part of a API 579 / ASME FSS review, indicates the reactor could still retain its original MAWP and MAEP, but has deformations in excess of UG-80 requirements, would ASME VIII still disallow...
All,
A recent API 510 internal inspection of our pressure vessel has revealed some distressing information. The PV has a half-pipe jacket covering most of the sidewall. At some point in the past, internal pressure of the jacket exceeded MAWP by a fair margin, buckling the internal wall that is...
1503-44,
The hearings themselves are public - any member of the public can attend. The resultant emergency plans that come from these meetings, usually from non-responding facilities and local emergency crew (firefighters, etc) are likely documented, but I think they are only available on...
1503-44,
That is why RMP regulations now require annual communications of hazards and risks associated with an RMP-covered process. The communication must take place at a local emergency planning committee, LEPCs, which are open to the public. However, I doubt the general community knows of the...
This is likely due to how the GC program is set up. Elution times from the GC must be quite similar at the given setup, causing a unimodal or broad pead. Thus, the program was told that "x" to "y" time is considered a mixture of propane and butane since it does not have the resolution to...
I remember being involved in a process experiment using H2S injection for a reactive distillation process. We brought in a dozen 200 lb bottles of H2S for the trial and slowly fed them into the process. I pulled a rotating 12-hour shift with another engineer. We carried around H2S monitors and...
Waross,
Shelter in place can be appropriate at times rather than evacuation. If concentrations in outside air are high or unknown, calling for an evacuation will cause most people to leave their homes, traversing the high concentrations to get to their cars.
Even if they make it to the car...
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.
Just an example for ethylene carbonate:
C3H4O3(s) + 2.5(O2)(g) -> 3(CO2)(g) + 2(H2O)(l)
Hcomb = (2*HfH2O+3*HfCO2) - (HfC3H4O3+HfO2)
Hcomb = (2*(-285 kJ/mol) + 3*(-393.5 kJ/mol))-(-581 kJ/mol + 0) = -1,169 kJ/mol
Note that this is the standard heat of formation, meaning it is taken at 298 K...
N8Cole,
Write out the combustion chemical formula and use the heats of formation (often found in NIST database) to determine the heat of combustion.
For those that NIST does not have the data (i.e. dimethyl carbonate), I found an online source that estimates the properties as well...
A last point of mine may have been missed. Have you or anyone else actually measured O2 concentration near the manway? Before you call it an issue and put in countermeasures, you need to actually prove it is an issue, and to what degree.
