4 replies to this topic

[Ra v]

Hello Everyone,

 

Could anyone explain me filling system of High pressurized Argon Cylinders.

 

We recently order a filling unit of gaseous ARGON of 200 bars, but unfortunately we received a unit of 165 Bars. We are now in big trouble because of our clients demand is always 200 bars Cylinders.

 

Please check the excel sheet attached for the flow diagram.

 

Now we are trying to fill the Argon cylinders by using our oxygen Compressor (200 Bars) by some changes.

 

As you see the diagram, Initially there is a

 

• Fixed Liquid Argon tank--- Liquid Argon pump (165 Bars)---- Ambient Vaporiser----- Filling Station. ( Actual System)

 

Changes are

Bypassing the Liquid argon pump (165 Bars) 

 

• Liquid Argon Truck--- Ambient Vaporiser--- Surge Tank ------ Oxygen Compressor----- Filling Station.

Question.

 

1. Liquid Argon pumping rate is  200-600 Lph, which we bypassed and from liquid Ar Truck we connected a hose directly to Ambient vaporiser, Is this enough for changing the liquid phase to gaseous phase? If not what are points to be considered?

 

2. If the liquid Argon not able to transfered in gas phase , then what are the main problem with our oxygen compressor.

 

3 Our Oxygen compresor flow rate is 150 Nm3/hr and suction pressure is 1.5 Bars; inorder to maintain that we are installing a pressure regulators to control the suction pressure. i.e  20 Bars --- 1.5 Bars. Is it necessary to put one surge vessel before compressor.?

 

So please help me ,our main  problem is that if we order the new filling unit of 200 Bars, then it will easily take us 60 Days . our liquid argon truck is on the way and will reach in  10 days so to avoid the loss of argon in truck we need to fill them in cylinders.

 

Please suggest me any ideas how can we transfer? Are there any other ideas? 

 

Waiting for the replies.

Attached Files

•  Arg.xlsx   16.79KB   16 downloads

[Art Montemayor]

Ravi:

 

As per prior posts, I presume you are still operating industrial gas plants in the Congo.  I also assume you have standard industrial gas plant equipment available to you.  You indicate this by saying you have an oxygen compressor (reciprocating, obviously) and a liquid Argon pump (which, although shown as a centrifugal type on your sketch, is a reciprocating, plunger type pump).  By standard, I mean that traditionally this type of equipment has been designed and operated to compress and pump industrial gases to 3,000 psig (200 barg) without any difficulty all over the world.

 

Filling compressed gas cylinders is something I did for many years as a young engineer.  I designed, installed, and operated various industrial gas plants in developing countries and never had any problems filling compressed gas cylinders with oxygen, nitrogen, or argon while using a plunger pump (most were Air Products pumps and some were Supaircos) or a reciprocating compressor (some were Air Liquide and others were Norwalk).  I always used ¾” Schedule 160 brass pipe and fittings which I screwed together and subsequently silver-soldered all the screwed joints.  What you call a “platform” is, in reality, a filling manifold for the high pressure cylinders.

 

You furnish no details on your equipment or installation and therefore I must presume you have standard equipment that can easily take the 200 barg operating pressure.  This should all be verified and confirmed with the designer-manufacturer.  That is the first and most important step you should have already taken.  If you have already done this, then please furnish all the detailed name plate and data sheet information on the pump, compressor, vaporizer, and all piping - including the manifold.  I never used a surge tank or vessel and never found a need for one.

 

If you have a liquid argon plunger pump, then that is the preferred way to fill compressed gas cylinders efficiently and safely.  A compressor would have to be a 5-stage unit, with more problems and higher energy consumption.  It is much less cost to operate a liquid pump with an ambient vaporizer at 200 barg.  My experience shows that people in the industry stopped using compressors to fill cylinders since I did it in the 1960s.  Reciprocating pumps are much simpler and easier to operate.

 

I would not use or rely on the oxygen compressor.  I see this as an easy and simple application to resolve in the field since I did it for many years without difficulties.

[Ra v]

Hello Art,

 

Thanks for the reply.

 

You are correct as you said that using Liquid Argon Pump is much less cost to operate, but the problem is the installation provided by the manufacturer is for a capacity of filling cylinders of 150 Bars only. I checked the name plates on the equipment.

 

Liquid Argon pump (Reciprocating) : 200 - 600 LPH,  Working Pressure : 150 Bar , Designed Pressure : 165 Bars

Vaporizer : Working Pressure : 150 Bars , Design Pressure : 165 Bars

 

But as i said, in Congo the clients prefer 200 Bars Argon Cylinders.

 

Is it possible to use the actual installation to fill the Argon cylinders upto 200 bars, The safety valve provided by manufacturer is popping at 165 Bars. So we are really concerned about filling the cylinders upto 200 bars with the actual installation .

 

So in order to fill the cylinders of 200 Bars, we are using the Oxygen Compressor ( Reciprocating 5- Stage ) to fill the gaseous Argon which will come from Argon Ambient Vaporizer as shown in the excel sheet named changes.

 

Is it really effective way to supply liquid Argon directly from Argon truck to Ambient Vaporiser bypassing the Liquid Argon pump?? Please check the excel as shown in the Sheet 2 named :: Changes 

 

Will the Phase transfer takes place i.e Liquid Argon ---- Gas Argon at the outlet of Ambient Vaporizer

 

Please find the attached images of Liquid Argon Pump and Safety valve Name plate.

 

 

Regards

A Ravi

 

 

 

 

Attached Files

•  Arg-1.xlsx   21.17KB   8 downloads
•  DSC_0005.JPG   114.4KB   1 downloads
•  DSC_0006.JPG   88.84KB   1 downloads

[Art Montemayor]

Is the designer-manufacturer of your equipment Chinese, Japanese, or Korean?  I can read either.

 

You are stuck with some off-standard equipment or by a manufacturer that is unfamiliar on how the compressed gas industry has evolved and is operating in the Western Hemisphere and the greater part of the globe.  As a consequence, you have gotten stuck with some very cheap and seemingly inexperienced designers.  As I stated before, it has always been standard practice to design cylinder filling, handling, and even hydro-testing equipment to operate safely at pressures up to 3,500 psig.  When designed accordingly, it costs the manufacturer no more to do that than to design to 2,300 psig (160 barg).  The cost of the equipment results in almost the same total price.  Only an inexperienced or isolated engineer would fail to know that.  There are practical and marketing reasons for designing to 3,500 psig filling and testing pressures.  There are standard high pressure gas cylinders and tubes designed for nominal 3,000 psig service in industrial and laboratory applications and we have always found that it doesn't cost any more to build a pump for 3,500 psig discharge than for 2,300 psig.

 

Even the vaporizer piping will only have a slight increase in cost for the higher pressure.  If a manufacturer is going to design for a standard package, he always does it for the higher rating.  I am sure that your supplier designed for a higher pressure - but they won't admit it (which should tell you what quality of supplier you have!).  Have you checked to see what pressure limits you have on your filling manifold?  And I don't mean that you should merely read the name plates.  Calculate the required wall thicknesses and check with what you have.

 

You say you "are using the Oxygen Compressor ( Reciprocating 5- Stage ) to fill the gaseous Argon which will come from Argon Ambient Vaporizer as shown in the excel sheet named change".  If so, then you have already made a decision to do that and you are using the compressor.  All I can comment to that is:  Good luck.  If you and your supplier cannot identify the capacity of your ambient vaporizer at the high and low operating pressures, then all you can do is try it and see what happens.  You don't tell us the capacity of your oxygen compressor under the new conditions and how you plan to control its delivery capacity.  That is why I say good luck.  Your bosses have put you in dire situation by buying cheap equipment and they expect you to supply a gas market with the same deficient equipment.  It reminds me of my early years in similar situations - thanks to my managers who wouldn't buy dependable, recognized equipment nor take the time to find out what problems they caused with their ignorant decisions.  The only way I could guess that you might be able to control the compressor capacity is using a recycle control valve from the compressor discharge to the suction side of the 1st stage.

 

Without any more basic data or background information, I am afraid that is all I can contribute at this time.  Sorry.

[Ra v]

Hello Art,

 

Yeah the manufacturer is Chinese.

 

As you said, If the manufacturer did the equipment manufacturing at standard practice then i guess we can charge the cylinders at 200 Bars, that will be good for us  instead of looking for other option using oxygen compressor.

 

There are two pressure regulators before the suction of oxygen compressor i.e 20 Bar---- 6 bar and the other 6 Bar-----1 Bar. Because the oxygen compressor suction is designed at 0.8 --- 1.5 Bar. Capacity of compressor is 150 Nm3/Hr.

 

Ambient Vaporizer rating is mentioned on name plate as i said earlier, i.e Working Pressure : 150 BAR , so i was worried if we go for 200 Bar then that will cause a damage for equipment as well as personnel .

 

Let me find some more info from the manufacturer and then i can supply some relevant data to resolve this problem.

 

Regards

A Ravi