Liquid Entrainment/Carryover from Inlet Separator

[ivegotgas]

Does anyone have any experience measuring entrained liquids from a gas stream.

We know we have a liquid carryover problem from our inlet separators but would like to quantify and identify the liquid.

We are proposing taking a gas sample and analyzing with a Hot GC run to charachterize the sample, then we can run the stream in a process simulator to determine the amount of condensation.

The main problem with this is obtaining a representative sample. I have heard that there is an ASTM standard for the sample procedure for taking gas samples for the purpose of liquid analysis, has anyone come across such a standard?

Thanks

 

[gr2vessels]

ivegotgas,
ivegot solution for you. Check out Perry Equipment website

http://www.perryequipment.com

for their DCM monitoring system(s). They have a few systems, very high accuracy, perhaps talk to them (similar systems are available in Europe also, try google for gas filter coalescers / monitoring systems).
Cheers, gr2vessels

 

[ivegotgas]

I should clarify. I am hoping to run a single test to determine the extent of liquid carryover, I am not looking to install monitoring systems at this time.

I am looking for a standard for sample collection, I've heard from others that ASTM has such a standard/procedure but I am having trouble finding it.

Thanks for the help so far.

 

[gr2vessels]

If you are able to provide a 2" flanged or threaded nozzle on the outlet pipe, minimum 3-5 diameters length from the flange face, they can give you one off test with their portable equipment or you can hire the equipment for a small number of tests, for vatious turn down conditions. It won't be economical to buy the testing equipment for one off test...The sample collection you mentioned is by now an obsolete and unaccurate method, the method of sizing the particles and count them "in process" is accurate, fast, reliable and a short time test could give you indication on process stability or a trend in time. Sorry, I can't help with the ASTM...
cheers,
gr2vessels

 

[mbeychok]

ivegot gas:

Does your vapor-liquid separator have a de-entrainment meshpad (or similar) just before the vapor outlet?

Milton Beychok
(Visit me at www.air-dispersion.com)
.

 

[monaco8774]

ivegot gas
This problem is very common. You have carryover and you want to prove and quantify it, heres a run down on ways to do it that I've used in the past starting from the cheapest to the most expensive:
1) Open a sample connection on gas outlet through a filter or rag to a suitable safe venting location - see what your picking up - more qualitative than quantitative this one but it does let you pick up intermittent faoming type problems and sort them from carry over/ entrainment ones
2) If you are getting reasonable amounts of produced water in your carryover you can use a simple chlorine test on the next scrubber or vessel along to estimate condensed water versus carryover
3) Expensive now - you can put a radioactive tracer liquid in upstream and measure directly how much is carried over versus ghow much goes out liquids this is done by guys like synetix and requires some planning but is pretty accurate if you have flowmeters on your system

Hope thats of use

 

[maddocks]

Several possibilities:

1.) Run a millipore test on a portion of the gas stream - basically this consists of running a small sidestream of the gas into a kind of coffee filter and analyzing what comes out on the surface of the filter paper. Not a very analytical test and can't tell you a lot.

2.) We've worked with local filter suppliers here in Calgary and Edmonton to run a small sidestream filter/coalescer (4") arrangement that runs for a preset time. They measure, and analyze the liquids collected and correlate that back to the main stream. Obviously the intent is to sell gas coalescer equipment but it's quite helpful in proving you have a problem.

Hope this helps

 

[73994]

I guess it all depends upon ur demister pad thickness, if u got one??? cuz in case u've one then the technique might be different as compare to no demister pad(wire mesh pad)...
I will refer u the GPSA standards for thsi purpose separator section, it will give u a rule of thumb to calculate such stuff, also Arnold's method of separator design gives u an idea of carry over stuff.
I have both the standards if I got any clue I'll let u knw
thanx
post the soln when ever u get it.

 

[jamesbanda]

Some considerations for you:

CALCULATE MAX Particle diameter that could be sent through your system: use stokes law based on velocity to determine what is the maximum particle size that can be conveyed in your system.
=2 [[ 9µ/(2g)(density1-density2) ] ^0.5 ]
Some reference particle sizes:
Atmosphic mist 4-50 microns
Drizzle 10-400 microns
Liquid boiling 20-1000 microns
rain drops 400-4000 microns

Does ti appear likely based on your system that you are getting those size droplets?

 

[davefitz]

There is a standard way to measure moisture in steam that leaves a steam drum. See astm d1066-06 and D1192. As I recall, the key is to provide isokinetic sampling and to have multiple sample ports across the pipe cross section if it is a large dia pipe, and there is a minimum distance between upstream elbows and the sample probes.