Drying of TitaniumTetraChloride ( TiCl4 ) 2

[chemengineerjunior]

Good Morning guys ,
As we are doing Acid cleaning in a pipe line which have 5 flanges till the end, after acid cleaning we will flush the pipe line with water , After drying of pipe line with air, Is there any chance of getting water deposited on the flange sites ???So our problem is that as the pipeline is handling TiCl4, TiCl4 + H20 -->> Ti02 + HCL .

So my questions are

1) with air is it possible to dry the pipe line or can u suggest some other gas that we can get complete dryness,

2) Is there any chance of getting water deposited on the flanges ? ( After drying with air , currently nitrogen cant be used for drying)

Its a Carbon Steel Line

 

[georgeverghese]

You could use -20degC to -40degC water dewpoint instrument air if you have a well operating mole sieves dryer in your plant to dry out this line. Purge with dry instr. air for several hours and then do a dewpoint check if you can.

Many plant instr. air systems with mole sieves dryers dont work well as they are bunged up with lube oil carry over from lube oil from oil flooded screw compressors.

 

[LittleInch]

You're new here so count this as a warning but double posting is not permitted and is usually red flagged.

Please don't do it again.

For others also see the same question in the pipeline forum.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[ash9144]

Use dry nitrogen. Gas providers, cylinders or bulk, provide nitrogen which has very low moisture content.

 

[EdStainless]

Unless your air has low dew point (-40) you won't get good drying. Using bulk (from liquid) Nitrogen would help.
Do you have any way to warm the flanges? Maybe some low powered electrical heat tracing on them would also help.
Why do you flush with water?
I thought that most of these systems were kept under dry inert gas purge at all times.

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P.E. Metallurgy, Plymouth Tube

 

[chemengineerjunior]

Thanks for all your replies

First of all sorry for double posting, It wont be repeated any more

@ash9144 and @EdStainless

Here in our case, we are doing chemical cleaning (acid cleaning) in a newly installed pipe line, and nitrogen is not available currently for drying ,
There are no heat tracing on the pipe lines as its new one.

But as your answers say we can use dry air with - 40 C dewpoint, so we need to purge the pipeline till we get -40C dewpoint at the exit point also ? Am i right ??

 

[Compositepro]

Drying water from crevices and low points in piping is very slow and not easy. The most reliable way is to bring the pipe above the boiling point of the fluid by applying heat or vacuum. At the boiling point, vaporization rate is limited by the rate of heat flow to the fluid. Below the boiling point the vaporization rate is limited by the diffusion rate of the vapor out of the crevice.
To visualize the difficulties it is helpful to think of crevices as similar to a Mason jar filled with water and with a 1 cm hole in the lid.

 

[don1980]

TiCl4 is violently reactive with water. This is not a casual question to toss out to a general audience. You need a very high-integrity procedure for drying this pipework to ensure that there is no moisture in any of the crevices (e.g. pipe flange connections). Contact your TiCl4 supplier to get the safety procedures generated by the TiCl4 manufacturer's association.

 

[EdStainless]

Honestly with this being a new installation I would ask people that have built these before.
I have done some plants that had similar issues, but not TiCl.
We acid cleaned, water rinsed, then flushed with a solvent. We brought in a tanker truck of liquid nitrogen and used that for final purge (and we heated the nitrogen).
If you have flange joints and -40 air you may need a couple of weeks to reach -30 DP, and there still could be some moisture in crevices.

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P.E. Metallurgy, Plymouth Tube

 

[ash9144]

Usually TiCl4 is handled in some type of dry solvent (ie Hexane, toluene, etc) If you are doing an acid flush then water flush why not come in with dry solvent and flush solvent through until dry? Flush solvent through until it is not increasing in moisture content.

 

[chemengineerjunior]

Thanks for all your replies.

After discussion we planned to dry the pipeline with dry air and get a dewpoint of -1C .

 

[EdStainless]

Is this in a place where the pipe is warm? Like at least 30C?
You should think about manually heating (maybe with an industrial heating blanket) just the flanges.

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P.E. Metallurgy, Plymouth Tube