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Originally Posted by 5161440

If someone have "analysis synthesis design of chemical processes" plz do share

Originally Posted by Mohamed

Viscosity and density are two properties of liquids and gases (or referred as fluids). They are very useful physical quantities when it comes to describing statics and dynamics of these substances. Viscosity and density alone can describe more than half the properties of a fluid. Viscosity Viscosity is defined as a measure of the resistance of a fluid which is being deformed by either shear stress or tensile stress. In more common words, viscosity is the “internal friction” of a fluid. It’s also referred as the thickness of a fluid. Viscosity is simply the friction between two layers of a fluid when the two layers move relative to each other. Sir Isaac Newton was a pioneer in fluid mechanics. He postulated that, for a Newtonian fluid, the shear stress between layers is proportional to the velocity gradient in the direction perpendicular to the layers. The proportional constant (proportionality factor) used here is the viscosity of the fluid. The viscosity is usually denoted by the Greek letter “µ”. Viscosity of a fluid can be measured using Viscometers and Rheometers. The units of viscosity are Pascal-seconds (or Nm^-2s). The cgs system uses the unit “poise”, named after Jean Louis Marie Poiseuille, to measure viscosity. Viscosity of a fluid can also be measured by several experiments. The viscosity of a fluid depends on the temperature. The viscosity decreases as the temperature is increased. Viscosity equations and models are very complex for non-Newtonian fluids. Density Density is defined as mass per unit volume. Density plays a vital role in fluid mechanics. Events such as up thrust are dependent on the density. Density is what we normally refer to as “weight” of a fluid. Density is a concept with which we are really familiar. It can be obtained from the simple equation density=mass/volume. Its units are Kgm^-3. What is the difference between Viscosity and Density? While most of the people think that viscosity and density are both the same

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besides being a user of Prode Properties I work in a factory where there are several centrifugal compressors and I am interested to the different topics concerning design and rating of these complex machines,
I post a question about Polytropic Compression Of Wet Gas (Efficiency Evaluation) with Prode Properties and the answer given by PaoloPemi in Cheresources, it includes several examples which I think could be of interest for the readers

question
recently we changed the inlet spec's of our (two stages) centrifugal compressor (natural gas), now we have about 1% fraction of condensate (value estimated with both Peng Robinson or Soave thermo packages) at inlet,
the manufacturer said it's acceptable and we are reevaluating efficiency (and power consumption),
My questions concern the evaluation of polytropic efficiency in case of wet gas,
we have measured pressures, temperatures etc. and calculated the polytropic efficiency with Prode Properties (selecting the procedure for polytropic solution with phase equilibria), at the new operating condition the value is close to the original number (0.76) for dry gas (that could be Ok since we have only 1% condensate on inlet line and dry gas at outlet),

1) to improve the accuracy, should I attempt (and why) to evaluate directly (i.e. measure) the amount of condensate on inlet line?
Actually the liquid fraction is calculated by Prode with Peng Robinson model.

2) the outlet temperature estimated with the correlation for ideal gas tout = tin*(pout/pin)^(k*eff) is very different from the value calculated with Prode Properties (Prode calculates lower temperatures), I suppose it is Ok considering we have a pressure ratio of about 4 and some condensate to evaporate.

answer

I am not aware of standards discussing the calculation procedure to estimate the polytropic efficiency of a compressor under wet gas (gas + liquid) conditions, ...

Tags: centrifugal, compressor, polytropic, prode, properties

Categories

Oil And Gas Process

Hello,

I am try to design heat exchanger using Hetran. Does anyone have user manual.

Thanks & Regards,

Buch

Originally Posted by tonycaden

Dear All,

Does anyone have the excel software in MS VBA and excel for calculating volume corrections factors, if so could they upload or email them to "avenobueno@ymail.com".

Thanks

I have found several papers discussing this topic, one is "Improved control valve sizing for multiphase flow" from Hydrocarbon Processing March 200, the authors say "HNE-DS method basically assumes that the flow pattern in the control valve is homogeneous but gas and liquid are not in equilibrium – a non-equilibrium factor N represents the boiling delay"
your comment agrees with this statement.
By the way I found also an interesting thread comparing API PSV formulation for gas flow here

'http://www.cheresources.com/invision/topic/16104-psv-discharging-temperature'

the author has provided a Excel page to compare different procedures

Discharging temperature (PSV outlet)
1) calculated with isentropic + adiabatic flash (the default in nozzle.xls)
2) calculated with adiabatic flash
3) calculated with isentropic flash

Calculated Area
1) rigorous numerical solution of isentropic nozzle
2) API formulation for gas and vapors, ideal cp/cv
3) API formulation for gas and vapors, real cp/cv
4) API formulation for gas and vapors, real cp/cv, Zv = 1

all the required properties are calculated by Prode library , for personal/academic use you can download a free -with limited number of components- copy from 'www.prode.com'

I recommend to read this thread to everyone interested in PSV sizing.
psvcompare1.xls

Tags: flow, gas, hem, liquid, psv

Categories

Uncategorized

cbadia wrote
for a two phase discharge I am sizing a relief valve with the isentropic Nozzle unit available in Prode Properties,
the procedure allows to specificy the HEM (Homogeneous Equilibrium Model) and NHNE (Non-Homogeneous Non-Equilibrium Model) for isentropic flow.
While the HEM model gives results consistent with those calculated by Excel page nozzle.xls distributed with the program the NHNE model requires specific settings and may give results quite different.
Which is the best option (HEM or NHNE) for modeling a PSV discahrge ?

I think it depends from several factors as for example the size of the valve and the physical properties of the fluid,
my version of Prode Properties has three models
HEM (Homogeneous Equilibrium Model)
HNE-DS (Homogeneous Non Equilibrium, simplified model)
NHNE Non Homogeneous Non Equilibrium)
the last two require a specific parameter which for HNE-DS is available in several papers while for NHNE you have to estimate the value, generally I select HEM and I do a test with HNE-DS

Tags: hem, hne-ds, psv, two-phase

Categories

Uncategorized

Originally Posted by jrtn

who can share GEOFRAME and OPENWORKS?
thanks

Dear All

Does anyone have a copy of ASTM D4940 a standard to measure the conductivity of abrasives. I also need a copy of ISO8502-5 a standard for measuring chloride contamination of a blast cleaned surface

Many thanks

Hello World!

This is a question for all folks who know about the salaries of Drilling Engineers and Reservoir Engineers.

Can someone tell me who gets more money overall yearly; a Drilling Engineer or a Reservoir Engineer? I have completed my BASc. degree in Petroleum Engineering and I like both Drilling and Reservoir fields, but I have no special preference for writing SPE papers, using fancy software or all of those paraphernalia that do not directly impact my salary; I just want to get into a field that helps me to maximize my earning potential while I am single and have the energy to work long hours and work hard. Being away from family is no big disadvantage for me.

I have just checked the SPE salary surveys from 2007 to 2011 and it seems that over time, the base salary for drilling engineers has steadily overtaken the base salary of reservoir engineers. Even in times when D.E.'s and R.E.'s get the same base salaries, can I assume that Drilling Engineers always get more money than Reservoir Engineers anyways due to the offshore allowances, since R.E.'s don't spend much time offshore?

Respectfully,

Markus L.