Steam flowmeters 1

[WilliamBarbosa]

Hello everyone,

Im looking for the most accurate flowmeters for satured steam aplication. I work in a steam outsorcing company, and I`m look into deeply in this matter.

I appreciate if you share your experiences and advices and collaborate with this matter for any steam satured aplication.

Thanks!

 

[hacksaw]

As you well understand, the answer depends on the details.
For example, pressure, temperature, flow rates, line size/layout, and degree of saturation.

 

[WilliamBarbosa]

Hacksaw, tks for reply

I have specific case, with 180ton/h, 19 barg and a pipeline with 16 inches.
But I dont want to limit this discussion just with this case, I would also like to know if anyone has experience with other process conditions for satured steam.

 

[TiCl4]

If you were to actually "look into deeply in this matter", you'd contact a reputable instrument manufacturer or their distributor (i.e. Endress Hauser, Emerson, etc) rather than random internet strangers like myself. You could discuss in detail your application specifics, and explore orifice meters, turbine meters, vortex meters, etc. Of particular concern is the question of how much condensate is present in the system, as many standard measuring principles can't handle two-phase flow.

 

[hacksaw]

William

Flow measurement of saturated steam is never accurate because of continuous condensate blow down, so your answer is driven mostly by cost.

Just contact your suppliers, they have the options you need.

 

[KevinNZ]

If are using the meter for invoicing then you can consider an orifice plate designed to an international standard. The steam supplier and the purchaser then have a document they can agree on and the flow meter implementation can then be audited to this standard.

 

[hacksaw]

Kev,
Not recommended with saturating steam. It would be a meaningless result.

 

[LittleInch]

Try these guys. Some of the best.

https://www.spiraxsarco.com/global/en-GB/products/flowmetering/target-flowmeters

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

 

[goutam_freelance]

Vortex meter may be suitable. If steam is almost dry you can try Coriolis meter also. But as others said you need to consult a reputed supplier (or suppliers).

Engineers, think what we have done to the environment !

https://www.linkedin.com/in/goutam-das-59743b30/

 

[TBP]

Years ago, in a former life with a district energy company, we used vortex shedders for our steam metering. For larger lines like you're talking about, we installed an insertion shedder bar through a thread-o-let. Smaller lines at customers, we used Yokogawa wafer style. Where possible, we used Cadillac or Adsco condenste meters, which are awesome because they are deadly accurate, with an infinite turndown. The drawbacks are they cannot - of course - capture any steam or condensate leaks ahead of them, and they measure any liquid as condensate. We had a customer that had their steam to hot water HX fail internally, and the meter cheerfully read the hot water heating loop water as condensate, resulting in a sky-high bill. We used the insertion meter on the main steam line out of the powerhouse, and compared that number against the monthly customer meter reading total to calculate the system line losses.

 

[danw2]

In-line ultrasonic flowmeters. GE/Baker Hughes

Link

 

[KevinNZ]

@hacksaw

Orifice plates are used for saturated (dry) steam all the time for our industry including transfer meters. Including their close relative the venturi meter or measuring steam turbine performance.

Why do you think they are no good?

 

[WilliamBarbosa]

Hi guys.

Tks for all replies. I`ve been talking with my suppliers (Emerson, Yokogawa, GE) about this topic. But as I said, I wrote this topic to know more experiences (including outside of my country) with steam flowmeters.

 

[hacksaw]

KevNz,

The original post dealt with "saturated" steam, which without any degree of superheat, has so much condensate, "slugging" tends to occur. Eccentric plates might work for occassional liquid buildup with weep holes, but orifice plates especicially concentric plates tend to work best in single phase applications.

Dave

 

[TBP]

Hacksaw - While I'm painfully aware that saturated steam systems like you describe exist in large numbers, I would suggest that adapting a metering strategy to suit a poorly installed/maintained/operated system is just yet another band-aid. If a given system is in such a poor state, that I would recommend that steam metering is the least of their worries, and that they should look at fixing the issues (and they are ALL fixable) and that steam metering should be much further down on their list of priorities.

We've been using saturated steam for way over 200 years, and all the kinks were worked-out long, long ago...

 

[hacksaw]

TBP,
The initial criteria was accurate metering. That requires a punch list of process data and installation issues that have to be dealt with.

Agreed that saturated steam was described and most plant insure some degree of superheat to avoid slugging events, but lacking further detail rather limits the followup, kinda', sorta'

 

[TBP]

Most of the plants I have worked in made no effort of any kind to provide any level of superheat. There should be no "slugging events" in any saturated steam system - ever. I have prevented them in systems I have designed & installed, and corrected them in systems I have inherited.